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Reference Manual Aspen Flare System Analyzer

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Page 1: Flarenet modelling

Reference Manual

Aspen Flare System Analyzer

Page 2: Flarenet modelling

Version: V7.3March 2011

Copyright (c) 1981-2011 by Aspen Technology, Inc. All rights reserved.

Aspen Flare System Analyzer, Aspen Flarenet, Aspen Plus, Aspen HYSYS, Aspen Plus Dynamics, andthe aspen leaf logo are trademarks or registered trademarks of Aspen Technology, Inc., Burlington,MA. All other brand and product names are trademarks or registered trademarks of their respectivecompanies.

This document is intended as a guide to using AspenTech's software. This documentation containsAspenTech proprietary and confidential information and may not be disclosed, used, or copied withoutthe prior consent of AspenTech or as set forth in the applicable license agreement. Users are solelyresponsible for the proper use of the software and the application of the results obtained.

Although AspenTech has tested the software and reviewed the documentation, the sole warranty forthe software may be found in the applicable license agreement between AspenTech and the user.ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITHRESPECT TO THIS DOCUMENTATION, ITS QUALITY, PERFORMANCE, MERCHANTABILITY, OR FITNESSFOR A PARTICULAR PURPOSE.

Aspen Technology, Inc.200 Wheeler RoadBurlington, MA 01803-5501USAPhone: (781) 221-6400Toll free: (888) 996-7001Website http://www.aspentech.com

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Contents i

Contents

1 Introduction.........................................................................................................1

About this document.........................................................................................1Audience.........................................................................................................1Related Documentation.....................................................................................1Technical Support ............................................................................................1

2 Components .........................................................................................................3

Overview.........................................................................................................3Selecting Components ......................................................................................4

Component Types ..................................................................................4Component List......................................................................................4Matching the Name String .......................................................................5Removing Selected Components ..............................................................5

Adding/Editing Components...............................................................................6Add Hypothetical Component/Edit Component ...........................................6Identification Tab ...................................................................................6Critical Tab............................................................................................7Other Tab..............................................................................................9Editing Database Components .................................................................9Estimating Unknown Properties.............................................................. 10

Organizing the Component List ........................................................................ 11Changing the Components .................................................................... 11Combining Components ........................................................................ 11

Binary Interaction Parameters ......................................................................... 11

3 Scenarios ...........................................................................................................15

Overview....................................................................................................... 15Scenario Manager .......................................................................................... 16Adding/Editing Scenarios................................................................................. 17

General Tab......................................................................................... 18Constraints Tab.................................................................................... 19Sources Tab ........................................................................................ 20Estimates Tab...................................................................................... 21

Scenario Tools ............................................................................................... 23Adding Single Source Scenarios ............................................................. 23

4 Pipe Network......................................................................................................25

Overview....................................................................................................... 25Pipe Manager................................................................................................. 25Ignoring/Restoring Pipes ................................................................................. 26

Connections Tab .................................................................................. 27Dimensions Tab ................................................................................... 29

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ii Contents

Fittings Tab ......................................................................................... 30Heat Transfer Tab ................................................................................ 32Methods Tab........................................................................................ 33Summary Tab ...................................................................................... 37Multiple Editing .................................................................................... 38Pipe Class Editor .................................................................................. 39

5 Nodes.................................................................................................................41

Overview....................................................................................................... 41Node Manager ............................................................................................... 41Ignoring/Restoring Nodes................................................................................ 42Connection Nodes .......................................................................................... 43

Connector ........................................................................................... 43Flow Bleed........................................................................................... 47Horizontal Separator............................................................................. 50Orifice Plate......................................................................................... 56Tee .................................................................................................... 60Vertical Separator ................................................................................ 65Summary Tab ...................................................................................... 70

Boundary Nodes............................................................................................. 71Control Valve....................................................................................... 71Relief Valve ......................................................................................... 81Source Tools........................................................................................ 94Flare Tip ............................................................................................. 95

6 Calculations......................................................................................................101

Starting the Calculations ............................................................................... 101Efficient Modeling Techniques ........................................................................ 102

Data Entry......................................................................................... 102Calculation Speed............................................................................... 103Sizing Calculations ............................................................................. 104

7 Databases ........................................................................................................107

Overview..................................................................................................... 107Database Features ....................................................................................... 108

Grid Controls ..................................................................................... 108Maneuvering Through the Table ........................................................... 109Printing............................................................................................. 109Adding/Deleting Data.......................................................................... 109

Setting The Password ................................................................................... 110Pipe Schedule Database Editor....................................................................... 110Fittings Database Editor ................................................................................ 112Component Database Editor .......................................................................... 112

Importing Component Data ................................................................. 113

8 Automation ......................................................................................................115

Overview..................................................................................................... 115Objects ....................................................................................................... 116

Object Hierarchy ................................................................................ 116The Aspen Flare System Analyzer Type Library ...................................... 117Object Browser .................................................................................. 117

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Contents iii

Automation Syntax............................................................................. 120Examples: Accessing Aspen Flare System Analyzer Object Properties ....... 123

Aspen Flare System Analyzer Object Reference................................................ 126Application ........................................................................................ 127Bleed................................................................................................ 128Bleeds .............................................................................................. 128Component........................................................................................ 129Components ...................................................................................... 130Connector ......................................................................................... 130Connectors........................................................................................ 131ControlValve...................................................................................... 132ControlValves .................................................................................... 133HorizontalSeparator............................................................................ 133HorizontalSeparators .......................................................................... 134Nodes ............................................................................................... 134OrificePlate........................................................................................ 135OrificePlates ...................................................................................... 135Pipe.................................................................................................. 136Pipes ................................................................................................ 138ReliefValve ........................................................................................ 139ReliefValves....................................................................................... 141Scenario ........................................................................................... 141Scenarios .......................................................................................... 142Solver............................................................................................... 142Tee .................................................................................................. 143Tees ................................................................................................. 144Tip ................................................................................................... 145Tips.................................................................................................. 146VerticalSeparator ............................................................................... 146VerticalSeparators.............................................................................. 147

Example – Automation In Visual Basic ............................................................ 147Updating Automation Files From Previous Versions ........................................... 155

9 Theoretical Basis ..............................................................................................157

Pressure Drop.............................................................................................. 157Pipe Pressure Drop Method.................................................................. 157Fittings Pressure Change Methods ........................................................ 165

Vapor-Liquid Equilibrium ............................................................................... 175Compressible Gas............................................................................... 175Vapor Pressure .................................................................................. 175Soave Redlich Kwong.......................................................................... 176Peng Robinson ................................................................................... 177

Physical Properties ....................................................................................... 178Vapor Density .................................................................................... 178Liquid Density.................................................................................... 178Vapor Viscosity .................................................................................. 179Liquid Viscosity .................................................................................. 179Liquid Phase Mixing Rules for Viscosity.................................................. 181Thermal Conductivity.......................................................................... 182Enthalpy ........................................................................................... 182

Noise .......................................................................................................... 186

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iv Contents

A File Format.......................................................................................................189

Import/Export Details ................................................................................... 189Process Descriptions........................................................................... 189Definition File Formats ........................................................................ 192Recognized Objects and Items ............................................................. 197

Report Files Format ...................................................................................... 215

B References .......................................................................................................221

C Glossary of Terms ............................................................................................223

Adiabatic Flow ............................................................................................. 223Choked Flow................................................................................................ 223Critical Pressure ........................................................................................... 223Critical Temperature ..................................................................................... 223Dongle........................................................................................................ 223Equivalent Length ........................................................................................ 223Isothermal Flow ........................................................................................... 224MABP.......................................................................................................... 224Mach Number .............................................................................................. 224Node .......................................................................................................... 224Reduced Pressure......................................................................................... 224Reduced Temperature................................................................................... 224Scenario ..................................................................................................... 224Schedule..................................................................................................... 225Security Device............................................................................................ 225Source ........................................................................................................ 225Static Pressure............................................................................................. 225Tailpipe....................................................................................................... 225Total Pressure.............................................................................................. 225Velocity Pressure.......................................................................................... 225

Index ..................................................................................................................226

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1 Introduction 1

1 Introduction

This section provides information on the following topics:

About this Document

Audience

Related Documentation

Technical Support

About this documentThe guide provides a detailed description of all the features and functionalitywithin Aspen Flare System Analyzer (previously called Aspen FLARENET).

AudienceThis guide is intended for process and process systems engineers.

Related DocumentationTitle Content

Aspen Flare System AnalyzerGetting Started Guide

Tutorials covering the basic use of AspenFlare System Analyzer

Technical SupportAspenTech customers with a valid license and software maintenanceagreement can register to access the online AspenTech Support Center at:

http://support.aspentech.com

This Web support site allows you to:

Access current product documentation

Search for tech tips, solutions and frequently asked questions (FAQs)

Search for and download application examples

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2 1 Introduction

Search for and download service packs and product updates

Submit and track technical issues

Send suggestions

Report product defects

Review lists of known deficiencies and defects

Registered users can also subscribe to our Technical Support e-Bulletins.These e-Bulletins are used to alert users to important technical supportinformation such as:

Technical advisories

Product updates and releases

Customer support is also available by phone, fax, and email. The most up-to-date contact information is available at the AspenTech Support Center athttp://support.aspentech.com.

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2 Components 3

2 Components

This section provides information on the following topics:

Overview

Selecting Components

Adding/Editing Components

Organizing the Component List

Binary Interaction Parameters

OverviewData for all components that will be used in the simulation must be selectedbefore the sources are defined. These components may be taken from thestandard component library, or you may define your own components, knownas hypothetical components.

You may select components from Component Manager, which can beaccessed by clicking Components in the Build group on the Home tab of theRibbon.

The Component Manager window will be displayed:

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4

Fig 2.1

This view displays all of theComponents, and provides various tools which you can use to add and editdatabase and hypothetical components.

Selecting Components

Component TypesYou may filter the list of available components to include only those belongingto a specific family.respectively, Invertexample, if only HydrocarbonsInvert, then these two check boxes would be cleared, while the remainingcheck boxes would be

Component ListComponents can be chosen from theto the Selected C

1 Arrow Keyscomponent.

2 PageUp/PageDownpage forward or backward.

This view displays all of the Available Components and Selected, and provides various tools which you can use to add and edit

and hypothetical components.

Selecting Components

Component TypesYou may filter the list of available components to include only those belongingto a specific family. All and None turn all of the filters on and off,

Invert toggles the status of each check box individually. As anexample, if only Hydrocarbons (HC) and Misc were selected, and you clicked

, then these two check boxes would be cleared, while the remainingcheck boxes would be selected.

Component ListComponents can be chosen from the Available Components

Components list, using one of the following methods:

– Use the arrow keys to move the highlight up or down one

PageUp/PageDown - Press these keyboard keys to advance an entirepage forward or backward.

2 Components

Selected, and provides various tools which you can use to add and edit

You may filter the list of available components to include only those belongingand off,

box individually. As anwere selected, and you clicked

, then these two check boxes would be cleared, while the remaining

list, and addedlist, using one of the following methods:

to move the highlight up or down one

Press these keyboard keys to advance an entire

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2 Components 5

3 Home/End - Press Home to move to the start of the list and End tomove to the end of the list.

4 Scroll Bar - Use the scroll bar to move up and down through the list.

Note: You can select multiple components by using the SHIFT or CTRL keys asyou select components.

5 Enter the component name from keyboard - When you type a letteror number, you will move to the next component in the list which startswith that character. If you repeatedly enter the same character, you willcycle through all of the components which start with that character.

To add a component, you must first highlight it (by moving through the listuntil that component is highlighted) and click to select, then transfer it bydouble-clicking it or clicking Add.

Matching the Name StringThe interpretation of your input is limited to the Component Types whichare checked.

Another way to add components is through the Selection Filter feature. TheSelection Filter box accepts keyboard input, and is used to locate thecomponent(s) in the current list that best matches your input.

You may use wildcard characters as follows:

? - Represents a single character.

* - Represents a group of characters of undefined length.

Any filter string has an implied * character at the end.

Some examples are shown here:

Filter Result

methan methanol, methane, etc.

*anol methanol, ethanol, propanol, etc.

?-propanol 1-propanol, 2-propanol

*ane methane, ethane, propane, i-butane, etc.

As you are typing into the Selection Filter box, the component list isupdated, matching what you have presently typed. You may not have to enterthe complete name or formula before it appears in the component list.

Removing Selected ComponentsYou can remove any component from the Selected Components list:1

Highlight the component(s) you want to delete.

2 Click Remove.

You can select multiple components using Shift-click and Ctrl-click to removethem all. Once the components are removed from the list, any sourcecompositions that used this component will be normalized.

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6

Adding/Editing ComponentsTo create a new component (hypothetical), clickcomponents are set up in thPreviously defined hypothetical components can be changed by selectingthem in the Selected Component

Add Hypothetical Component/EditComponentUpon clicking either

Identification TabThe minimum data requirements for creating a component are specified here

Fig 2.2

Component Types

Hydrocarbon (

Miscellaneous (

Amine

Adding/Editing ComponentsTo create a new component (hypothetical), click Hypotheticalcomponents are set up in the same manner as database components.Previously defined hypothetical components can be changed by selecting

Selected Components list and clicking Edit.

Add Hypothetical Component/EditComponentUpon clicking either Hypothetical or Edit, the Component Editor

Identification TabThe minimum data requirements for creating a component are specified here

Component Types

Hydrocarbon (HC)

Miscellaneous (Misc)

2 Components

Adding/Editing ComponentsHypothetical. Hypothetical

e same manner as database components.Previously defined hypothetical components can be changed by selecting

mponent Editor opens up.

The minimum data requirements for creating a component are specified here:

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2 Components 7

Alcohol

Ketone

Aldehyde

Ester

Carboxylic Acid (Carbacid)

Halogen

Nitrile

Phenol

Ether

The following fields are available on this tab:

Input Field Description

Name An alphanumeric name for the component (e.g. - Hypo -1).

Type The type of component (or family) can be selected from the listprovided. There is a wide selection of families to choose from, whichallows better estimation methods to be chosen for that component.

ID The ID number is provided automatically for new components andcannot be edited.

Mol. Wt. The molecular weight of the component.

NBP The normal boiling point of the component.

Std. Density The density of the component as liquid at 1 atm and 60 F.

Watson K The Watson characterization factor.

Critical TabCritical properties are specified here.

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8

Fig 2.3

The following field

Input Field

Critical Pres.

Critical Temp.

Critical Volume

Char. Volume

Acentric Factor

Acent. Fact. (SRK)

The following fields are available on this tab:

Description

The critical pressure of the component. If the componentrepresents more than a single real component, the pseudocritical pressure should be used.

The critical temperature of the component. If the componentrepresents more than a single real component, the pseudocritical temperature should be used.

The critical volume of the component. If the componentrepresents more than a single real component, the psecritical volume should be used.

The characteristic volume of the component. If the componentrepresents more than a single real component, the pseudocharacteristic volume should be used.

The acentric factor of the component.

Acent. Fact. (SRK) The Soave-Redlich-Kwong acentric factor of the component(also called the COSTALD Acentricity).

2 Components

The critical pressure of the component. If the componentrepresents more than a single real component, the pseudo

e of the component. If the componentrepresents more than a single real component, the pseudo

The critical volume of the component. If the componentrepresents more than a single real component, the pseudo

The characteristic volume of the component. If the componentrepresents more than a single real component, the pseudo

Kwong acentric factor of the component

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2 Components

Other TabCoefficients for the polynomial equations for the prediction of Ideal Gasthermodynamic properties and parameters for the vispecified here:

Fig 2.4

The following fields are available on this tab:

Input Field

Hi A, Hi B, Hi C, Hi D, Hi E, andHi F

Entropy Coef.

Viscosity A and Viscosity B

Editing Database ComponentsIf you want to change the data for one of the database components, e.g.Methane, you will find thatcomponent will display

Other TabCoefficients for the polynomial equations for the prediction of Ideal Gasthermodynamic properties and parameters for the viscosity calculations are

The following fields are available on this tab:

Description

Hi A, Hi B, Hi C, Hi D, Hi E, and The coefficients for the ideal gas specific enthalpyequation:

The coefficient for the entropy equation.

Viscosity A and Viscosity B Viscosity coefficients used in the NBS Method (Elyand Hanley, 1983).

Editing Database ComponentsIf you want to change the data for one of the database components, e.g.Methane, you will find that opening the Component Editor for thiscomponent will display read-only values that cannot be changed.

Hi

A BT CT2 DT3 ET4 FT+ + + + +=

9

Coefficients for the polynomial equations for the prediction of Ideal Gasscosity calculations are

The coefficients for the ideal gas specific enthalpy

nt for the entropy equation.

Viscosity coefficients used in the NBS Method (Ely

If you want to change the data for one of the database components, e.g.for this

values that cannot be changed.

FT5

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10

Fig 2.5

In order to update the data for a database component it must first bechanged to a hypothetical comp

At the very minimum, you need to specify the Molecular Weight. However, itis a good practice to specify at least two of the following properties:

Molecular Weight (

Normal Boiling Point (

Standard Density (

This is done by clicking

Estimating Unknown PropertiesIf any of the above data is unknown, clickproperties.

Supply as many properties as are known, soaccurate as possible.

In order to update the data for a database component it must first bechanged to a hypothetical component.

At the very minimum, you need to specify the Molecular Weight. However, itis a good practice to specify at least two of the following properties:

Molecular Weight (Mol. Wt.)

Normal Boiling Point (NBP)

Standard Density (Std. Density)

clicking Hypothetical in the Component Editor

Estimating Unknown PropertiesIf any of the above data is unknown, click Estimate to fill-in the unknown

Supply as many properties as are known, so that the estimation can be asaccurate as possible.

2 Components

In order to update the data for a database component it must first be

At the very minimum, you need to specify the Molecular Weight. However, itis a good practice to specify at least two of the following properties:

Component Editor.

in the unknown

that the estimation can be as

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2 Components 11

Organizing the Component ListThe Selected Components list can be organized in the following differentways.

Changing the ComponentsYou can switch the components in the Selected Components list with theones in the Available Components list while maintaining the source molefractions.

In Component Manager, select the components in both the SelectedComponents and the Available Components lists. Click Switch to switchthe two components.

Combining ComponentsMultiple components can be combined and represented by a single componentto reduce the number of components in the model.

To combine multiple components:

1 Select the components you want to combine by Ctrl-clicking them in theSelected Components list.

2 Click Combine.

The Component Combination window will be displayed, and ask you toselect which basis should be used. The highlighted component in the boxat the upper part of the window is the target component to combine yourselected components into. Once the basis has been selected the combinedcomponents will update each source in the model by summing thecomposition of all of the combined components and assigning it to thetarget component.

Reducing the number of components in this way is useful since it can greatlyspeed the calculations. This is especially true where a model contains sourcesdefined with a long list of hypothetical components.

For example, consider a model containing the hypothetical componentsBP200, BP225, BP250, BP275, BP300 boiling at 200°C, 225°C, 250°C, 275°Cand 300°C respectively. Since these components are likely to stay in theliquid phase throughout the flare system, they may be combined into a singlecomponent, BP250 without significant loss of accuracy. As another example,in a purely gas phase flare system it is possible to combine isomers such as i-Butane and n-Butane into a single component n-Butane withoutcompromising results.

Binary Interaction ParametersBinary Interaction Coefficients, often known as KIJ’s, are factors that are usedin equations of state to better fit the interaction between pairs of componentsand hence improve the accuracy of VLE calculations. You are allowed tospecify binary interaction parameters for the Peng Robinson and Soave

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12

Redlich Kwong VLE methods or to estimate them through thetab of the Component Manager

Fig 2.6

To define binary interaction coefficientsRobinson or Soave Redlich Kwongat the top of the window.

Note: Binary interacCompressible Gas

Individual binary interaction parameters are set by selecting the requiredentry in the matrix and typing in the new value.

Note: The matrix is symmetrian entry will also update the corresponding entry in the table. E.g. updatingthe entry in the Methane column, Propane row will also update the entry inthe Propane column, Methane row.

Individual binaryrequired entry in the matrix and clickingmethod is based on the componentscritical volume.

It is possible to set several binaeither by Ctrl-clicking the two corners of a rectangular area in the matrix. Theselected entries can then be estimated by clickingby clicking Zero HC

Redlich Kwong VLE methods or to estimate them through the Binary CoeffsComponent Manager as shown here.

To define binary interaction coefficients, first select either theSoave Redlich Kwong VLE method from the VLE Method

at the top of the window.

Binary interaction coefficients are not used by either theGas or Vapor Pressure VLE methods at present

Individual binary interaction parameters are set by selecting the requiredentry in the matrix and typing in the new value.

The matrix is symmetrical i.e. KJI is the same value as Kan entry will also update the corresponding entry in the table. E.g. updatingthe entry in the Methane column, Propane row will also update the entry inthe Propane column, Methane row.

Individual binary interaction parameters may be estimated by selecting therequired entry in the matrix and clicking Estimate HC. The estimationmethod is based on the components' boiling point, standard liquid density and

It is possible to set several binary interaction parameters at the same timeclicking the two corners of a rectangular area in the matrix. The

selected entries can then be estimated by clicking Estimate HCZero HC-HC.

2 Components

Binary Coeffs

first select either the PengVLE Method list

tion coefficients are not used by either theVLE methods at present.

Individual binary interaction parameters are set by selecting the required

is the same value as KJI, and updatingan entry will also update the corresponding entry in the table. E.g. updatingthe entry in the Methane column, Propane row will also update the entry in

interaction parameters may be estimated by selecting the. The estimation

boiling point, standard liquid density and

ry interaction parameters at the same timeclicking the two corners of a rectangular area in the matrix. The

HC or set to 0.0

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2 Components 13

Clicking Reset All causes all interaction parameters to be set to their defaultvalues. Generally this is 0.0 for hydrocarbon components with non zerovalues being supplied only for common polar components.

If the Auto Estimate check box is selected, then the interaction parametersfor new components are automatically estimated as they are added to themodel.

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14 2 Components

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3 Scenarios 15

3 Scenarios

This section provides information on the following topics:

Overview

Scenario Manager

Adding/Editing Scenarios

Scenario Tools

OverviewA scenario defines a set of source conditions (flows, compositions, pressuresand temperatures) for the entire network. The design of a typical flare headersystem will be comprised of many scenarios for each of which the headersystem must have adequate hydraulic capacity. Typical scenarios mightcorrespond to:

Plant wide power failure

Plant wide cooling medium or instrument air failure

Localized control valve failure

Localized fire or Depressurization

The scenario management allows you to simultaneously design and rate theheader system for all of the possible relief scenarios.

Note: Although the major relief scenarios will normally constrain the size ofthe main headers, care should be taken in the evaluation of velocities in theindividual relief valve tailpipes and sub headers. When looking at relief valveswhich might operate alone, lower back pressures in the main headers maylead to localized high velocities and consequently choked flow in the tail pipes.

As well as having different source conditions, each scenario can have uniquedesign limitations that will be used either to size the pipes or to highlightproblems when an existing flare system is being rated. For example, a Machnumber limit of 0.30 might be applied for normal flaring compared to a Machnumber limit of 0.50 or greater at the peak flows encountered during plantblowdown.

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16 3 Scenarios

Scenario ManagerScenarios can also be selected by selecting the scenario from the list in Rungroup on the Home tab of the Ribbon.

Fig 3.1

Scenarios are managed via the Scenario Manager. This window allows youto add, edit or delete scenarios as well as to select the current scenario forwhich scenario specific data is displayed. All cases have at least one scenario.

To access the Scenario Manager

On the Home tab, in Build, click Scenarios.

Scenario Manager will be displayed:

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3 Scenarios

Fig 3.2

The Scenario Managercurrent scenario. Several buttons are available:

Button

Clone

Edit

Delete

Current

Close

Adding/Editing ScenariosAspen Flare System Analyzer has no prescenarios which can

To add a scenario,then click Clone

To edit a scenario, highlight it, and then click

The Scenario Editor

Scenario Manager displays all scenarios in the case, and indicates thecurrent scenario. Several buttons are available:

Description

Clones the highlighted scenario and adds a new scenario tothe Scenarios list.

Edits the highlighted scenario.

Removes the currently highlighted scenario. There mustalways be at least one scenario in the case.

To make a scenario the current one, highlight the appropriatescenario, and then click Current.

Closes the Scenario Manager.

Adding/Editing ScenariosAspen Flare System Analyzer has no pre-programmed limits on the number ofscenarios which can be defined within a single case.

To add a scenario, highlight a existing scenario in the Scenariosin the Scenario Manager.

To edit a scenario, highlight it, and then click Edit.

The Scenario Editor will be displayed.

17

displays all scenarios in the case, and indicates the

es the highlighted scenario and adds a new scenario to

Removes the currently highlighted scenario. There must

rent one, highlight the appropriate

Adding/Editing Scenariosprogrammed limits on the number of

Scenarios list, and

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18

General TabYou may provide the following information on the

Fig 3.3

Data

Name

System Back Pres

General TabYou may provide the following information on the General tab:

Description

An alphanumeric description of the scenario (e.g. PowerFailure).

System Back Pres. The system back pressure at the Flare Tip exit. Thinormally be atmospheric pressure, but can be set to representsystem design conditions at the exit point. If left empty, thevalue on the Calculation Options Editor will be used. Theminimum value is 0.01 bar (absolute pressure).

3 Scenarios

tab:

An alphanumeric description of the scenario (e.g. Power

ip exit. This willnormally be atmospheric pressure, but can be set to representsystem design conditions at the exit point. If left empty, the

will be used. Theminimum value is 0.01 bar (absolute pressure).

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3 Scenarios

Constraints TabThis tab requires the following information for both headers and tailpipes.

Fig 3.4

Tailpipes are indicated by thePipe Editor. You may provide different design information (Noise at 1 m, Vapor VelTailpipes. Any boxes may be left empty, in which case they will be ignored.

Data

Mach Number

Vapor Velocity

Liquid Velocity

Constraints Tabis tab requires the following information for both headers and tailpipes.

Tailpipes are indicated by the Tailpipe field on the Connections. You may provide different design information (Mach Number

Vapor Velocity, Liquid Velocity) for the Headers. Any boxes may be left empty, in which case they will be ignored.

Description

The maximum allowable Mach number for all pipe segments.Calculated values that exceed this number will be highlighted in theresults.

The maximum allowable vapor velocity. Calculated velocities thatexceed this value will be indicated in the results.

The maximum allowable liquid velocity. Calculated velocities thatexceed this value will be indicated in the results.

19

is tab requires the following information for both headers and tailpipes.

Connections box of theMach Number,

Headers and. Any boxes may be left empty, in which case they will be ignored.

The maximum allowable Mach number for all pipe segments.e highlighted in the

The maximum allowable vapor velocity. Calculated velocities that

The maximum allowable liquid velocity. Calculated velocities that

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20 3 Scenarios

Rho V2 The density times the velocity square. This value is normally usedas a limiting factor to prevent erosion.

Noise The maximum allowable sound pressure level at a distance of 1meter for all pipe segments. This is an average value over thelength of the pipe. Calculated values that exceed this specificationwill be highlighted in the results.

Check Vel.Constraint

Specify either Mixture Velocity or Phase Superficial Velocity isused while checking the velocity constraints for design in ascenario.

Note: Whilst rating the network you may define a Mach number constraint of1.00, in order to highlight only choked flow conditions. This is notrecommended for design calculations where a more reasonable value such as0.5 or 0.7 will lead to a more rapid solution towards the maximum allowableback pressure constraints.

Sources TabIf a source is ignored, the MABP constraint is ignored by sizing calculations.

When you select the Sources tab, you will see that all sources are displayedon this tab.

Note: If you are setting up a new case, the Sources tab will not show anysources.

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3 Scenarios

Fig 3.5

This tab is useful in that you can easily toggle whether or not individualsources are to be included in the current scenario,unnecessarily delete sources or set the flow of a source to zero.

Estimates TabThe Estimates tab allows some control over the selection and initialization offlowrates for pipes which are to be used as tears in the solution of loosystems. The use to which each field is put is dependent upon theAnalyzer setting on the

The check boxes in thepipes from being used as tearsbeing used as a tear or clear it to allow it. This setting has no effect if theSimultaneous structural analyzer is used.

When the Convergentrecommends a tear locatiIf the structural analyzer does find that the pipe may be a valid tear locationthen this value is ignored.

This tab is useful in that you can easily toggle whether or not individualsources are to be included in the current scenario, without having to eitherunnecessarily delete sources or set the flow of a source to zero.

Estimates Tabtab allows some control over the selection and initialization of

flowrates for pipes which are to be used as tears in the solution of loosystems. The use to which each field is put is dependent upon the

setting on the Solver tab of Calculation Options Editor

The check boxes in the No Tear column of the table allow you to preventpipes from being used as tears - select the check box to prevent a pipe frombeing used as a tear or clear it to allow it. This setting has no effect if the

structural analyzer is used.

Convergent structural analyzer is used, the Molar Flowrecommends a tear location and initial value for the flow at the tear location.If the structural analyzer does find that the pipe may be a valid tear locationthen this value is ignored.

21

This tab is useful in that you can easily toggle whether or not individualwithout having to either

unnecessarily delete sources or set the flow of a source to zero.

tab allows some control over the selection and initialization offlowrates for pipes which are to be used as tears in the solution of loopedsystems. The use to which each field is put is dependent upon the Structure

Calculation Options Editor.

column of the table allow you to preventt the check box to prevent a pipe from

being used as a tear or clear it to allow it. This setting has no effect if the

Molar Flow columnon and initial value for the flow at the tear location.

If the structural analyzer does find that the pipe may be a valid tear location,

Page 28: Flarenet modelling

22

When the Simultaneousis used to seed thlong as the structural analysis succeeds but the pipe will not necessarily beselected as a tear pipe. In the event that the structural analysis fails with anyMolar Flow estimates

Fig 3.6

Since the Simultaneousperformance than thespecify information on theimproving the speed of convergence of the model. In the event that a modelproves problematic to converge, a number of additional columns are availableto tune the convergence algorithms. These may be exposed by stretching theview horizontally.

The Max. Step column defines the maximum change to the flow in a tearpipe over a single iteration whilst theconstrain the flow in a tear pipe. Not all these values are used by all theSolver algorithms.

Simultaneous structural analyzer is used, the Molar Flowis used to seed the analyzer. This value will always impact the initialization aslong as the structural analysis succeeds but the pipe will not necessarily beselected as a tear pipe. In the event that the structural analysis fails with any

estimates, the model will be initialized by the default values.

Simultaneous structural analyzer generally offers betterperformance than the Convergent analyzer it will rarely be necessary tospecify information on the Estimates tab other than for the purimproving the speed of convergence of the model. In the event that a modelproves problematic to converge, a number of additional columns are availableto tune the convergence algorithms. These may be exposed by stretching theview horizontally.

column defines the maximum change to the flow in a tearpipe over a single iteration whilst the Max. Flow and Min. Flowconstrain the flow in a tear pipe. Not all these values are used by all the

algorithms.

3 Scenarios

Molar Flow columne analyzer. This value will always impact the initialization as

long as the structural analysis succeeds but the pipe will not necessarily beselected as a tear pipe. In the event that the structural analysis fails with any

will be initialized by the default values.

structural analyzer generally offers betteranalyzer it will rarely be necessary to

tab other than for the purpose ofimproving the speed of convergence of the model. In the event that a modelproves problematic to converge, a number of additional columns are availableto tune the convergence algorithms. These may be exposed by stretching the

column defines the maximum change to the flow in a tearMin. Flow columns

constrain the flow in a tear pipe. Not all these values are used by all the Loop

Page 29: Flarenet modelling

3 Scenarios 23

Max. Step Max. Flow Min. Flow

Newton-Raphson 3 3 3

Broyden 3 3 3

Force Convergent

Conjugate Gradient Minimisation

Quasi-Newton Minimization

Scenario ToolsThe complete analysis of a flare system should ideally include analysis of thesystem for the scenarios in which each source relieves on its own. For a largenetwork with many sources, it can become tedious to define each of thesescenarios. These can automatically be added to your model as follows.

Adding Single Source ScenariosClick Source Tools from the Tools group on the Home tab of the Ribbon,then select Add Single Source Scenarios or use the hot key combinationAlt, H, U, A. Click OK for the message that pops up.

This will analyze your model and add a scenario for each source that has anon-zero flow rate defined in at least one scenario. Source data will be copiedfrom the scenario in which it has the highest flow rate.

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24 3 Scenarios

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4 Pipe Network 25

4 Pipe Network

This section provides information on the following topics:

Overview

Pipe Manager

Ignoring/Restoring Pipes

Multiple Editing

OverviewThe pipe network comprises a series of interconnected pipes. These pipes canbe added, edited and deleted from the Pipe Manager.

Pipe ManagerTo access the Pipe Manager, click Pipes in the Build group on the Hometab of the Ribbon.

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26

Fig 4.1

The following buttons are available:

Button Description

Add Adds a new pipe segment. This new pipe will be named with a numberdepending upon the number of pipes already ad

Edit Edits the currently highlighted pipe segment.

Delete Removes the currently highlighted pipe segment.

Close Closes the

Ignoring/Restoring PipesWhen you ignore a single pipe, all upstream pipes are automatically ignored.

You can ignore single or multiple pipes within the model. When you ignore asingle pipe, all upstream nodes are automatically ignored. This enables you todo what if type calculations, where part of the network can be excluded fromthe calculation without the needappropriate nodes.

To ignore a pipe:

1 Open the Pipe Editor

2 On the Connections

The following buttons are available:

Description

Adds a new pipe segment. This new pipe will be named with a numberdepending upon the number of pipes already added.

Edits the currently highlighted pipe segment.

Removes the currently highlighted pipe segment.

Closes the Pipe Manager.

Ignoring/Restoring PipesWhen you ignore a single pipe, all upstream pipes are automatically ignored.

ignore single or multiple pipes within the model. When you ignore asingle pipe, all upstream nodes are automatically ignored. This enables you to

type calculations, where part of the network can be excluded fromthe calculation without the need for deletion and reinstallation of theappropriate nodes.

To ignore a pipe:

Pipe Editor window of the pipe that you want to ignore.

Connections tab, select the Ignore check box.

4 Pipe Network

Adds a new pipe segment. This new pipe will be named with a number

Ignoring/Restoring PipesWhen you ignore a single pipe, all upstream pipes are automatically ignored.

ignore single or multiple pipes within the model. When you ignore asingle pipe, all upstream nodes are automatically ignored. This enables you to

type calculations, where part of the network can be excluded fromfor deletion and reinstallation of the

window of the pipe that you want to ignore.

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4 Pipe Network 27

Fig 4.2

To restore a pipe that has previously been ignored:

1 Open the Pipe Editor window of the pipe that you want to restore.

2 On the Connections tab, clear the Ignore check box.

Connections TabThe name of the pipe segment and connectivity information is specified here.

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28

Fig 4.3

The following fields are available on this tab:

Input Data Description

Name An alphanumeric description of the pipe segment.

Location An alphanusegment.

UpstreamNode

This is the name of the node upstream of the pipe. The list allowsyou to select from a list of existing unconnected nodes in the model.

DownstreamNode

This is the nameyou to select from a list of existing unconnected nodes in the model.

Tailpipe This list allows you to select whether the pipe should be treated as atailpipe. If set tooption is selected in thepressure drop for this pipe will be calculated using the rated flow inplace of the relieving flow rate.

Ignore This checkcalculationnodes and pipes will be ignored during calculations.

Fitting Loss The fitting loss for the pipe segment. You cannot change the valueshown in this box. Instead, calculated value on thebe updated by clicking

The following fields are available on this tab:

Description

An alphanumeric description of the pipe segment.

An alphanumeric description of the location within the plant for thesegment.

This is the name of the node upstream of the pipe. The list allowsyou to select from a list of existing unconnected nodes in the model.

This is the name of the node upstream of the pipe. The list allowsyou to select from a list of existing unconnected nodes in the model.

This list allows you to select whether the pipe should be treated as atailpipe. If set to Yes and the Rated Flow for Tailpipoption is selected in the Calculation Options dialog box, thepressure drop for this pipe will be calculated using the rated flow inplace of the relieving flow rate.

This check box may be selected to remove the pipe fromcalculations temporarily. When selected the pipe and all upstreamnodes and pipes will be ignored during calculations.

The fitting loss for the pipe segment. You cannot change the valueshown in this box. Instead, calculated value on thebe updated by clicking Link or Paste.

4 Pipe Network

meric description of the location within the plant for the

This is the name of the node upstream of the pipe. The list allowsyou to select from a list of existing unconnected nodes in the model.

of the node upstream of the pipe. The list allowsyou to select from a list of existing unconnected nodes in the model.

This list allows you to select whether the pipe should be treated as aRated Flow for Tailpipes calculation

dialog box, thepressure drop for this pipe will be calculated using the rated flow in

box may be selected to remove the pipe froms temporarily. When selected the pipe and all upstream

nodes and pipes will be ignored during calculations.

The fitting loss for the pipe segment. You cannot change the valueshown in this box. Instead, calculated value on the Fittings tab can

Page 35: Flarenet modelling

4 Pipe Network

You have the option of modeling a pipe segment as a main header or atailpipe. The ability to classify a pipe as either a tailpipe or a header allowsyou to perform calculations in which the pressure drop for tailpidetermined by the rated flow and that for headers is determined by thenominal flow. This is in accordance with API

In the Scenario EditorVapor and Liquid Velocitiesheaders and the tailpipes.

Dimensions TabThe physical dimensions and characteristics of the pipe segment are specifiedhere.

Fig 4.4

The following fields are available on this tab:

Input Data

Length

You have the option of modeling a pipe segment as a main header or atailpipe. The ability to classify a pipe as either a tailpipe or a header allowsyou to perform calculations in which the pressure drop for tailpidetermined by the rated flow and that for headers is determined by thenominal flow. This is in accordance with API-RP-521.

Scenario Editor, you can set design limits for the Mach NumberLiquid Velocities, Rho V2 and Noise separately for the main

headers and the tailpipes.

Dimensions TabThe physical dimensions and characteristics of the pipe segment are specified

The following fields are available on this tab:

Description

The physical length of the pipe segment. This length is used inassociation with the fittings loss coefficients to calculate theequivalent length of the pipe. If you have equivalent length datafor your network, enter this data here as the sum of the actual

29

You have the option of modeling a pipe segment as a main header or atailpipe. The ability to classify a pipe as either a tailpipe or a header allowsyou to perform calculations in which the pressure drop for tailpipes isdetermined by the rated flow and that for headers is determined by the

Mach Number,ly for the main

The physical dimensions and characteristics of the pipe segment are specified

the pipe segment. This length is used inassociation with the fittings loss coefficients to calculate theequivalent length of the pipe. If you have equivalent length datafor your network, enter this data here as the sum of the actual

Page 36: Flarenet modelling

30 4 Pipe Network

Input Data Description

length plus the equivalent length of the fittings and enter zero forthe fittings loss coefficients.

Elevation Change A positive elevation indicates that the outlet is higher than theinlet.

Material The pipe material, either Carbon Steel or Stainless Steel.

Roughness The surface roughness of the pipe segment. Whenever a materialis selected, the absolute roughness is initialized to the defaultvalue for the material as defined on the Preferences view.

ThermalConductivity

The thermal conductivity of the pipe wall. This is used by theheat transfer calculations when these are enabled.

NominalDiameter

The nominal pipe diameter used to describe the pipe size. Forpipes with a nominal diameter of 14 inches or more, this will bethe same as the outside diameter of the pipe.

Schedule Select a schedule number from the list, you will be able to selecta nominal pipe diameter from the pipe databases. It will not benecessary to specify the Internal Diameter or the WallThickness for the pipe.

InternalDiameter

The pipe diameter used for the pressure drop calculations.

Wall Thickness The thickness of the pipe wall. Valid values are any positivenumber or zero.

Use Class Select Yes to restrict the pipe sizes to those defined by the PipeClass.

Sizeable If you wish the pipe segment to be resized by sizing calculations,Yes should be selected. For example, a model of a networkcontaining a representation of the knockout drum, as a pipesegment would normally leave this unchecked such that sizingcalculations for the pipes would not change the knockout drumsize.

Schedule Numbers

Carbon Steel:

10, 20, 30, 40, 60, 80, 100, 120, 140, 160, STD, XS, XXS, User

Stainless Steel:

5S, 10S, 40S, 80S

Fittings TabA list of pipe fittings may be added to the pipe segment. These fittings will bemodeled as an additional equivalent length applied linearly over the physicallength of the pipe segment.

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4 Pipe Network

Fig 4.5

The following fields are available on this tab:

Input Data

LengthMultiplier

Fittings Loss

From the Database Fittingthen click Add to mselect as many fittings as required. The final fitting loss equation, which willbe a sum of all the selected fittings, will appear in a display field underneaththe Selected Fitting

Click Link to transfer the coefficients for this equation into thefield on the Connections

Click Paste to transfer the coefficients for the fitting equation into theFittings Loss field

To remove the selected fitting individually, select the fitting and click

The following fields are available on this tab:

Description

The length of the pipe is multiplied by this value to determine theequivalent length used for the pressure drop calculation. If leftblank then the value on the Calculation Options EditorThis option is useful for making an allowance for bends and otherfittings if these are not known.

The fittings "K" factor is calculated from the following equation inwhich Ft is the friction factor for fully developed turbulent flow:

K = A + BFt

Database Fittings list, select the appropriate type of fitting, andto move the selection to the Selected Fittings

select as many fittings as required. The final fitting loss equation, which willbe a sum of all the selected fittings, will appear in a display field underneath

Selected Fittings list.

to transfer the coefficients for this equation into theConnections tab, while maintaining the list of fittings.

to transfer the coefficients for the fitting equation into thefield. The selected list of fittings will not be retained.

To remove the selected fitting individually, select the fitting and click

31

ue to determine theequivalent length used for the pressure drop calculation. If left

Calculation Options Editor is used.This option is useful for making an allowance for bends and other

The fittings "K" factor is calculated from the following equation inis the friction factor for fully developed turbulent flow:

list, select the appropriate type of fitting, ands list. You can

select as many fittings as required. The final fitting loss equation, which willbe a sum of all the selected fittings, will appear in a display field underneath

to transfer the coefficients for this equation into the Fittings Loss, while maintaining the list of fittings.

to transfer the coefficients for the fitting equation into theof fittings will not be retained.

To remove the selected fitting individually, select the fitting and click Delete.

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32

Note: The network cannot be sized correctly if you specify equivalent lengthdata to model fittings losses, since the equivalent length of aa function of the pipe diameter and will therefore be incorrect when thediameters change.

Heat Transfer TabThe pipe segment may perform calculations taking into account heat transferwith the external air.

Fig 4.6

The following field

Input Data

External Conditions Group

External Medium

Temperature

The network cannot be sized correctly if you specify equivalent lengthdata to model fittings losses, since the equivalent length of any pipe fitting isa function of the pipe diameter and will therefore be incorrect when thediameters change.

Heat Transfer TabThe pipe segment may perform calculations taking into account heat transferwith the external air.

The following fields are available on this tab:

Description

External Conditions Group

Select the external medium. Two options arecurrently available: Air or Sea Water

Enter the temperature of the external air. If this fieldis left blank, the global value set via theOptions Editor is used.

4 Pipe Network

The network cannot be sized correctly if you specify equivalent lengthny pipe fitting is

a function of the pipe diameter and will therefore be incorrect when the

The pipe segment may perform calculations taking into account heat transfer

Select the external medium. Two options areSea Water.

Enter the temperature of the external air. If this fieldthe global value set via the Calculation

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4 Pipe Network 33

Input Data Description

External Medium Velocity Enter the velocity of the external medium. If this fieldis left blank, the global value set via the CalculationOptions Editor is used.

Heat Transfer Enabled This list selects whether heat transfer calculations areto be performed for the pipe. Furthermore, settingonly enables heat transfer calculations if the EnableHeat Transfer option is also selected in theCalculation Options Editor.

External Radiative HTC This list selects whether or not the external radiativeheat transfer coefficient is included within the heattransfer calculations.

Emissivity Enter the fractional Emissivity to be used forradiative heat transfer calculations.

Multiple Element Calculation This list selects whether the heat transfer calculationis done using a single element or the same number ofelements as the pressure drop calculation. If Yes isselected, the heat transfer calculation sues the samenumber of elements as the pressure drop calculation

Insulation Group

Description A brief description to identify the type of pipeinsulation.

Thickness Supply the insulation thickness.

Thermal Conductivity Enter the insulation thermal conductivity.

Heating Group

Outlet Temp You can explicitly set an outlet temperature for thissegment, or leave it blank. A heater in a flareknockout drum is an example of process equipmentthat may require a fixed outlet temperature.

Duty Enter the heating duty and the outlet temperaturewill be calculated based on the inlet temperature andthe defined duty.

Methods TabCalculation methods are specified here.

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34

Fig 4.7

The following fields are available on this tab:

Input Field Description

VLE Method Group

VLE Method The options for the Vafollows (see

The following fields are available on this tab:

Description

VLE Method Group

The options for the Vapor-Liquid Equilibrium calculations are asfollows (see Chapter 9 Theoretical Basis for more details):

Compressible Gas - Real Gas relationship. This is onlyavailable when the Enthalpy Method on theOptions Editor is Ideal Gas.

Peng Robinson - Peng Robinson Equation of Stateavailable when the Enthalpy Method on theOptions Editor is NOT Ideal Gas.

Soave Redlich Kwong - Soave Redlich Kwong Equation ofState. This is available when the Enthalpy MethodCalculation Options Editor is NOT Ideal Gas

Vapor Pressure - Vapor Pressure method as described in APITechnical Data Book Volume 113. This is available when theEnthalpy Method on the Calculation Options EditorNOT Ideal Gas.

Model Default - If this is selected, the Default method for theVLE method (as defined on the Calculation Options Editorwill be used.

4 Pipe Network

Liquid Equilibrium calculations are asfor more details):

This is onlyon the Calculation

Peng Robinson Equation of State. This ison the Calculation

Soave Redlich Kwong Equation ofEnthalpy Method on the

Ideal Gas.

Vapor Pressure method as described in APIThis is available when the

Calculation Options Editor is

If this is selected, the Default method for theCalculation Options Editor)

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4 Pipe Network 35

Input Field Description

Pressure Drop Group

Horizontaland InclinedPipes

The Horizontal/Inclined methods apply only when you haveselected Two-Phase pressure drop. The options are:

Isothermal Gas - This is a compressible gas method thatassumes isothermal expansion of the gas as it passes alongthe pipe. Aspen Flare System Analyzer uses averagedproperties of the fluid over the length of the pipe. The outlettemperature from the pipe is calculated by adiabatic heatbalance either with or without heat transfer. Pressure lossesdue to change in elevation are ignored.

Adiabatic Gas - This is a compressible gas method thatassumes adiabatic expansion of the gas as it passes along thepipe. As with the Isothermal Gas method, pressure losses dueto changes in elevation are ignored.

Beggs & Brill - The Beggs and Brill method is based on workdone with an air-water mixture at many different conditions,and is applicable for inclined flow.

Dukler - Dukler breaks the pressure drop in two-phasesystems into three components - friction, elevation andacceleration. Each component is evaluated independently andadded algebraically to determine the overall pressure drop.

Lockhart Martinelli – Lockhart Martinelli correlations modelsthe two phase pressure drop in terms of a single phasepressure drop multiplied by a correction factor. Accelerationchanges are not included.

Beggs and Brill (No Acc.) – The Beggs and Brill methodswithout the acceleration term.

Beggs and Brill (Homog.) – The Beggs and Brill methods witha homogeneous acceleration term.

Dukler (AGA Head) - Uses the AGA equation for thecalculation of the static head term rather than the Eatonequation which can be poor when you have small quantities ofliquid in the system.

Model Default - If this is selected, the Default method for theHorizontal/Inclined method (as defined on the CalculationOptions Editor) will be used.

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36 4 Pipe Network

Input Field Description

VerticalPipes

The Vertical method applies only when you have selected Two-Phasepressure drop. The options are:

Isothermal Gas - This is a compressible gas method thatassumes isothermal expansion of the gas as it passes alongthe pipe. Aspen Flare System Analyzer uses averagedproperties of the fluid over the length of the pipe. The outlettemperature from the pipe is calculated by adiabatic heatbalance either with or without heat transfer. Pressure lossesdue to change in elevation are ignored.

Adiabatic Gas - This is a compressible gas method thatassumes adiabatic expansion of the gas as it passes along thepipe. As with the Isothermal Gas method, pressure losses dueto changes in elevation are ignored.

Beggs & Brill - Although the Beggs and Brill method was notoriginally intended for use with vertical pipes, it isnevertheless commonly used for this purpose, and istherefore included as an option for vertical pressure dropmethods. For more details, see Chapter 9 Theoretical Basis.

Dukler - Although the Dukler method is not generallyapplicable to vertical pipes, it is included here to allowcomparison with the other methods.

Orkiszewski - This is a pressure drop correlation for vertical,two-phase flow for four different flow regimes - bubble, slug,annular-slug transition and annular mist. For more details,see Appendix A - Theoretical Basis.

Lockhart Martinelli – Lockhart Martinelli correlations modelsthe two phase pressure drop in terms of a single phasepressure drop multiplied by a correction factor. Accelerationchanges are not included.

Beggs and Brill (No Acc.) – The Beggs and Brill methodswithout the acceleration term.

Beggs and Brill (Homog.) – The Beggs and Brill methods witha homogeneous acceleration term.

Model Default - If this is selected, the Default method for theVertical method (as defined on the Calculation OptionsEditor) will be used.

Elements For two-phase calculations, the pipe segment is divided into aspecified number of elements. On each element, energy and materialbalances are solved along with the pressure drop correlation. Insimulations involving high heat transfer rates, many increments maybe necessary, due to the non-linearity of the temperature profile.Obviously, as the number of increments increases, so does thecalculation time; therefore, you should try to select a number ofincrements that reflects the required accuracy.

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4 Pipe Network 37

Input Field Description

FrictionFactorMethod

The Friction Factor Method applies only when you have entered avalue for friction factor. The options are:

Round - This method has been maintained primarily forhistorical purposes in order for older Aspen Flare SystemAnalyzer calculations to be matched. It tends to over predictthe friction factor by up to 10% in the fully turbulent region.

Chen - It should always be the method of preference since itgives better predictions at the fully turbulent flow conditionsnormally found within flare systems.

Model Default - If this is selected, the Default method for theFriction Factor Method (as defined on the CalculationOptions Editor) will be used.

Static HeadContribution

The following options are available:

Include - The static head contribution to total pressure drop inthe pipe segments is included.

Ignore Downhill Recovery - The static head recovery term isignored for downhill sections of pipe.

Ignore - The static head contribution to the pressure dropcalculation for all pipe segments is ignored.

Include is applied by default.

Solver Group

DampingFactor

The damping factor used in the iterative solution procedure. If this isleft blank, the value in the Calculation Options Editor is used.

Note: When you are sizing a flare system, the initial pipe diameters mayaffect the solution when there is a liquid phase and the liquid knockout drumis modeled. You should initially size a network using vapor phase methods.

Summary TabThe results of the calculation are displayed.

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38

Fig 4.8

Multiple EditingYou can edit multiple pipe segments simultaneouslthe Pipe Managerpressed. After you have finished selecting pipe segments, clickthe common Pipe Editor

The common pipe editor view differs from that of the single pin the following respects:

Only fields that can be edited in multiple mode are displayed.

The input fieldsthat the value should remain at the pre edit value.

In the following figure of theLengthnot be changed. We specify new values for thethe Thermal ConductivitySizeable

Multiple EditingYou can edit multiple pipe segments simultaneously by highlighting them in

Pipe Manager with the mouse cursor while keeping the Spressed. After you have finished selecting pipe segments, click

Pipe Editor.

The common pipe editor view differs from that of the single pipe editor viewin the following respects:

Only fields that can be edited in multiple mode are displayed.

The input fields have an additional entry, *. This entry indicatesthat the value should remain at the pre edit value.

In the following figure of the Dimensions tab; we enter * for theLength and Elevation Change fields to indicate that these mustnot be changed. We specify new values for the Roughness

Thermal Conductivity. We select * for the Use ClassSizeable boxes to indicate that these must be changed.

4 Pipe Network

y by highlighting them inShift key

pressed. After you have finished selecting pipe segments, click Edit to open

ipe editor view

Only fields that can be edited in multiple mode are displayed.

have an additional entry, *. This entry indicates

tab; we enter * for thefields to indicate that these must

Roughness andUse Class and

must be changed.

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4 Pipe Network

Fig 4.9

Pipe Class EditorThe Pipe Class Editornominal diameter, for bothcalculations. It also allows you to restrict the range of pipe sizes that may beselected during design calculations.

To access the Pipe Class Editortab.

Pipe Class EditorPipe Class Editor allows you to edit the allowable schedules for each

nominal diameter, for both Carbon Steel and Stainless Steels. It also allows you to restrict the range of pipe sizes that may be

selected during design calculations.

Pipe Class Editor, click Pipe Class in Tools, on the

39

allows you to edit the allowable schedules for eachStainless Steel, during sizing

s. It also allows you to restrict the range of pipe sizes that may be

, on the Home

Page 46: Flarenet modelling

40 4 Pipe Network

Fig 4.10

Note: If you have selected Use Pipe Class in the Preference Editor, theseare the schedules which will be used.

Page 47: Flarenet modelling

5 Nodes 41

5 Nodes

This section provides information on the following topics:

Overview

Node Manager

Ignoring/Restoring Nodes

Connection Nodes

Boundary Nodes

OverviewPipes are connected via nodes, which can be added, edited and deleted fromthe Node Manager. Sources are also added through the Node Manager.

Node ManagerTo access the Node Manager:

Click Nodes in Build, on the Home tab.

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42

Fig 5.1

The following buttons are available:

Button Description

Add You will be prompted to select the type of node. This new node will benamed with a number depending upon the number of nodes of thattype already added.

Edit Allows you to edit the currently highlighted node. The form varies,depending

Delete Allows you to remove the currently highlighted node.

Close Closes the

Ignoring/Restoring NodesWhen you ignore a single node, all upstream nodes are automatically ignored.

You can ignore sinsingle node, all upstream nodes are automatically ignored. This enables youto do what if type calculations, where part of the network can be excludedfrom the calculation without the need for deletappropriate nodes.

To ignore a node

1 Open the node editor

2 On the Connectionsfigure shows this for a connector node

The following buttons are available:

Description

You will be prompted to select the type of node. This new node will benamed with a number depending upon the number of nodes of thattype already added.

Allows you to edit the currently highlighted node. The form varies,depending on the type of node, as discussed below.

Allows you to remove the currently highlighted node.

Closes the Node Manager.

Ignoring/Restoring NodesWhen you ignore a single node, all upstream nodes are automatically ignored.

You can ignore single or multiple nodes within the model. When you ignore asingle node, all upstream nodes are automatically ignored. This enables you

type calculations, where part of the network can be excludedfrom the calculation without the need for deletion and reinstallation of theappropriate nodes.

To ignore a node:

Open the node editor of the node that you want to ignore.

Connections tab, select the Ignore check box. The fofigure shows this for a connector node.

5 Nodes

You will be prompted to select the type of node. This new node will benamed with a number depending upon the number of nodes of that

Allows you to edit the currently highlighted node. The form varies,

Ignoring/Restoring NodesWhen you ignore a single node, all upstream nodes are automatically ignored.

gle or multiple nodes within the model. When you ignore asingle node, all upstream nodes are automatically ignored. This enables you

type calculations, where part of the network can be excludedion and reinstallation of the

box. The following

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5 Nodes 43

Fig 5.2

To restore a node that has previously been ignored:

1 Open the node editor of the node that you want to restore.

2 On the Connections tab, clear the Ignore check box.

Connection NodesThe following types of connection nodes are available in Aspen Flare SystemAnalyzer. A connection node is one that links two or more pipe segments.

Connector

Flow Bleed

Horizontal Separator

Orifice Plate

Tee

Vertical Separator

ConnectorThe Connector is used to model the connection of two pipes. The diametersof the pipes may be different.

Page 50: Flarenet modelling

44

Connections Tab

The name of the connector and connectivity information is

Fig 5.3

The location can have an alphanumeric name. This feature is useful for largeflowsheets, because you can provide a different “location” name to differentsections to make it more comprehensible.

The following fields are available

Field Description

Name The alphanumeric description of the1).

Location You may want to specify the location of the node in the plant.

Upstream/Downstream

Either type in the name of the pipe segment or select

At You can specify the end of the pipe segment attached to theconnector.

Ignore Select thecalculations. Clear the check

Calculations Tab

Calculation methods are spec

Connections Tab

The name of the connector and connectivity information is specified here.

The location can have an alphanumeric name. This feature is useful for largeflowsheets, because you can provide a different “location” name to differentsections to make it more comprehensible.

The following fields are available on this tab:

Description

The alphanumeric description of the Connector (e.g.1).

You may want to specify the location of the node in the plant.

Either type in the name of the pipe segment or select

You can specify the end of the pipe segment attached to theconnector.

Select the Ignore check box to ignore this connector in thecalculations. Clear the check box to re-enable it.

Calculations Tab

Calculation methods are specified here.

5 Nodes

specified here.

The location can have an alphanumeric name. This feature is useful for largeflowsheets, because you can provide a different “location” name to different

(e.g. - HP Connect

You may want to specify the location of the node in the plant.

Either type in the name of the pipe segment or select from the list.

You can specify the end of the pipe segment attached to the

box to ignore this connector in the

Page 51: Flarenet modelling

5 Nodes

Fig 5.4

The following fields are available on this tab:

Field Description

Angle Specify the connector expansion angle. If not defined, it will becalculated

Length Enter the connector length. If not defined, it will be calculaAngle

Fitting LossMethod

The available options are:

IsothermalPressure Drop

If this option is set tochange calculations in the connector will not update during iterativecalculations for pressure loss i.e. a PT flash will be used to updatethe inlet properties. If the option isflash will be used to update the inlet properties.

The connector will do one size change calculation between the inletand outlet diameters selecting expansion or contraction asappropriate.

Setting this option toat cost of a minor loss of accuracy.

Two PhaseCorrection

If this option is set toflow will be calculated using properties corrected for liquid slip. If settocalculating the pressure loss coefficient.

The following fields are available on this tab:

Description

Specify the connector expansion angle. If not defined, it will becalculated from Length.

Enter the connector length. If not defined, it will be calculaAngle.

The available options are:

Equal Static Pressure – Pressure drop calculation is ignoredand static pressure is balanced.

Calculated – Pressure drop is calculated in accordance withthe Swage method.

If this option is set to Yes, the inlet temperatures used for the sizechange calculations in the connector will not update during iterativecalculations for pressure loss i.e. a PT flash will be used to updatethe inlet properties. If the option is set to No, a more rigorous PHflash will be used to update the inlet properties.

The connector will do one size change calculation between the inletand outlet diameters selecting expansion or contraction asappropriate.

Setting this option to Yes can speed up calculations in some casesat cost of a minor loss of accuracy.

If this option is set to Yes, the pressure loss coefficient in two phaseflow will be calculated using properties corrected for liquid slip. If setto No, the homogenous properties of the fluid will be used incalculating the pressure loss coefficient.

45

Specify the connector expansion angle. If not defined, it will be

Enter the connector length. If not defined, it will be calculated from

Pressure drop calculation is ignored

Pressure drop is calculated in accordance with

, the inlet temperatures used for the sizechange calculations in the connector will not update during iterativecalculations for pressure loss i.e. a PT flash will be used to update

a more rigorous PH

The connector will do one size change calculation between the inletand outlet diameters selecting expansion or contraction as

ed up calculations in some cases

the pressure loss coefficient in two phaseflow will be calculated using properties corrected for liquid slip. If set

enous properties of the fluid will be used in

Page 52: Flarenet modelling

46 5 Nodes

Field Description

SwageMethod

The following options are available:

Compressible - pressure losses will be calculated assumingcompressible flow through the connector at all times.

Incompressible (Crane) - pressure losses will be calculatedassuming incompressible flow through the connector at alltimes. Loss coefficients are calculated using Cranecoefficients.

Transition - pressure losses will be calculated initially usingthe assumption of incompressible flow. If the pressure lossexpressed as a percentage of the inlet pressure is greaterthan the defined compressible transition value then thepressure drop will be recalculated using the compressibleflow method.

Incompressible (HTFS) - pressure losses will be calculatedassuming incompressible flow through the connector at alltimes. Loss coefficients are calculated using HTFScorrelations

The Incompressible method calculations are faster but will beless accurate at higher pressure drops. The Transition methodcan cause instabilities in some cases if the calculated pressuredrop is close to the transition value.

Balance Total Pressure – Frictional pressure drop is ignoredand total pressure is balanced between upstream &downstream.

CompressibleTransition

This entry defines the pressure drop as a percentage of the inletpressure at which compressible flow pressure drop calculationsshould be used. It applies only when the Transition method isselected.

Summary Tab

The result of the calculations at each of the pipe connections is displayed.

Page 53: Flarenet modelling

5 Nodes

Fig 5.5

Flow BleedThe Flow Bleed is a simple calculation block that allows you to;

Specify a fixed pressure drop

Specify a constrained flow offtake whfrom the following equation

Offtake = Multiplier x Inlet Flow + Offset

The calculated Offtake is constrained to maximum and minimum values.

Connections Tab

The name of the flow bleed and connectivity information is speci

Flow BleedThe Flow Bleed is a simple calculation block that allows you to;

Specify a fixed pressure drop.

Specify a constrained flow offtake where the flow offtake is calculatedfrom the following equation:

Offtake = Multiplier x Inlet Flow + Offset

The calculated Offtake is constrained to maximum and minimum values.

Connections Tab

The name of the flow bleed and connectivity information is speci

47

The Flow Bleed is a simple calculation block that allows you to;

ere the flow offtake is calculated

The calculated Offtake is constrained to maximum and minimum values.

The name of the flow bleed and connectivity information is specified here.

Page 54: Flarenet modelling

48

Fig 5.6

The following fields are available on this tab:

Field Description

Name The alphanumeric description of theXX).

Location You may want to specify the location of the

Upstream/Downstream

Either type in the name of the pipe segment or select from the list.

At You can specify the end of the pipe segment attached to theb

Ignore Select thecalculations. Clear the check

Calculations Tab

Calculation methods are specified here.

The following fields are available on this tab:

Description

The alphanumeric description of the Flow Bleed (e.g.XX).

You may want to specify the location of the node in the plant.

Either type in the name of the pipe segment or select from the list.

You can specify the end of the pipe segment attached to thebleed.

Select the Ignore check box to ignore this flow bleed in thecalculations. Clear the check box to re-enable it.

Calculations Tab

Calculation methods are specified here.

5 Nodes

(e.g. - HP Connect

in the plant.

Either type in the name of the pipe segment or select from the list.

You can specify the end of the pipe segment attached to the flow

box to ignore this flow bleed in the

Page 55: Flarenet modelling

5 Nodes

Fig 5.7

The following fields are available on this tab:

Field

Offtake Multiplier

Offtake Offset

Offtake Minimum

OfftakeMaximum

Pressure Drop

Summary Tab

The result of the calculations at each of the pipe connections is displayed.

The following fields are available on this tab:

Description

Specify the Offtake multiplier. The default value is 0.

Specify the Offset for the Offtake to compensate for the changesin the inlet flow.

Specify the minimum value for the Offtake.

Specify the maximum value for the Offtake.

Enter the pressure drop across the Flow Bleed.

ry Tab

The result of the calculations at each of the pipe connections is displayed.

49

Specify the Offtake multiplier. The default value is 0.

et for the Offtake to compensate for the changes

The result of the calculations at each of the pipe connections is displayed.

Page 56: Flarenet modelling

50

Fig 5.8

Horizontal SeparatorHorizontal separators are used to allow liquid to separate from the feedstream so that it can be removed from the flare system. The liquid phase inthe horizontal separatorSystem Analyzer, thesecondary inlet/outlet, and one vapor outl

Connections Tab

The name of the horizontal separator and connectivity information is specifiedhere.

Horizontal Separatoreparators are used to allow liquid to separate from the feed

m so that it can be removed from the flare system. The liquid phase ineparator feed is removed from the network. In Aspen Flare

System Analyzer, the Horizontal Separator has one primary inlet, onesecondary inlet/outlet, and one vapor outlet stream.

Connections Tab

The name of the horizontal separator and connectivity information is specified

5 Nodes

eparators are used to allow liquid to separate from the feedm so that it can be removed from the flare system. The liquid phase in

feed is removed from the network. In Aspen Flarehas one primary inlet, one

The name of the horizontal separator and connectivity information is specified

Page 57: Flarenet modelling

5 Nodes

Fig 5.9

You only need to provide 2 of 3 connections to be able to solve the separator.This allows for solution(s) to partially built network

The following fields are available on this tab:

Field

Name

Location

(Primary/Secondary)Inlet/Outlet

At

Ignore

Calculations Tab

Calculation methods are specified here.

You only need to provide 2 of 3 connections to be able to solve the separator.This allows for solution(s) to partially built networks.

The following fields are available on this tab:

Description

The alphanumeric description of the Horizontal Separator(e.g. - HP KO Drum).

You may want to specify the location of the nodeThe location can have an alphanumeric name. This feature isuseful for large flowsheets, because you can provide a different“location” name to different sections to make it morecomprehensible.

Either type in the name of the pipe segment or selectlist.

You can specify the end of the pipe segment attached to thehorizontal separator.

Select the Ignore check box to ignore this horizontal separatorin the calculations. Clear the check box to re-enable it.

Calculations Tab

tion methods are specified here.

51

You only need to provide 2 of 3 connections to be able to solve the separator.

Horizontal Separator

node in the plant.hanumeric name. This feature is

useful for large flowsheets, because you can provide a different“location” name to different sections to make it more

Either type in the name of the pipe segment or select from the

You can specify the end of the pipe segment attached to the

box to ignore this horizontal separatorenable it.

Page 58: Flarenet modelling

52

Fig 5.10

The following fields are available on this tab:

Field

Dimensions Group

Diameter

Liquid Level

Methods Group

Fitting LossMethod

The following fields are available on this tab:

Description

Dimensions Group

The internal diameter of the vessel.

The liquid level in the vessel. Pressure drop is calculated basedupon the vapor space above the liquid.

The available options are;

Equal Static Pressure – Pressure drop calculation is ignoredand static pressure is balanced.

Calculated_Ignore Vena Contracta – Pressure drop iscalculated in accordance with the Swageignores the loss due vena contracta.

Calculated – Pressure drop is calculated in accordance withthe Swage method including the loss due vena contracta.

5 Nodes

The liquid level in the vessel. Pressure drop is calculated based

Pressure drop calculation is ignored

Pressure drop ismethod but

Pressure drop is calculated in accordance withmethod including the loss due vena contracta.

Page 59: Flarenet modelling

5 Nodes 53

Field Description

IsothermalPressure Drop

If this option is set to Yes, the inlet temperatures used for the sizechange calculations in the separator will not update duringiterative calculations for pressure loss i.e. a PT flash will be used toupdate the inlet properties. If the option is set to No, a morerigorous PH flash will be used to update the inlet properties.

The horizontal separator does three size change calculations, onebetween each stream connection and the vessel body. Normallythese will be expansion calculations for the primary and secondaryinlets and a contraction calculation for the vapor outlet but theywill automatically change if flows are reversed.

Setting this option to Yes can speed up calculations in some casesat cost of a minor loss of accuracy.

Size Change Group

Two PhaseCorrection

If this option is set to Yes, the pressure loss coefficient in twophase flow will be calculated using properties corrected for liquidslip. If set to No, the homogenous properties of the fluid will beused in calculating the pressure loss coefficient.

Method The following options are available:

Compressible - Pressure losses will be calculated assumingcompressible flow through the connector at all times.

Incompressible (Crane) - Pressure losses will be calculatedassuming incompressible flow through the connector at alltimes. Loss coefficients are calculated using Cranecoefficients.

Transition - Pressure losses will be calculated initially usingthe assumption of incompressible flow. If the pressure lossexpressed as a percentage of the inlet pressure is greaterthan the defined compressible transition value then thepressure drop will be recalculated using the compressibleflow method.

Incompressible (HTFS) - Pressure losses will be calculatedassuming incompressible flow through the connector at alltimes. Loss coefficients are calculated using HTFScorrelations

The Incompressible method calculations are faster but will beless accurate at higher pressure drops. The Transition methodcan cause instabilities in some cases if the calculated pressuredrop is close to the transition value.

Balance Total Pressure – Frictional pressure drop is ignoredand total pressure is balanced between upstream &downstream.

CompressibleTransition

This entry defines the pressure drop as a percentage of the inletpressure at which compressible flow pressure drop calculationsshould be used. It applies only when the Transition method isselected.

Page 60: Flarenet modelling

54

Field

BodyDimension

Composition Tab

If the inlet feed flashes in the separator and as a result ofmixture is converted into liquid fully andThis can cause instability in the pressure solution of the whole network. Toavoid this, Aspen Flare System Analyzervery small vapor fraction for the vapor outlet (<0.001%).composition of the vapor phase here.

Fig 5.11

Description

If this option is set to Full Body Area, the calculation for theprimary inlet/vessel and secondary inlet/vessel size change wiuse the whole vessel area. If Partial Body Area on Flowselected, the vessel area is reduced in proportion to theappropriate flow, i.e. if the secondary inlet volumetric flow is 20%of the total volumetric flow in the tee then 20% of the body areawill be used in the size change calculation. The use of theBody Area on Flow option has the effect of increasing thepressure loss calculated by simple fixed K factors.

Composition Tab

If the inlet feed flashes in the separator and as a result of the flash, theis converted into liquid fully and the vapor outlet will have no flow.

instability in the pressure solution of the whole network. ToAspen Flare System Analyzer creates an arbitrary vapor phase with

all vapor fraction for the vapor outlet (<0.001%). Youcomposition of the vapor phase here.

5 Nodes

the calculation for theprimary inlet/vessel and secondary inlet/vessel size change will

Partial Body Area on Flow isthe vessel area is reduced in proportion to the

i.e. if the secondary inlet volumetric flow is 20%of the total volumetric flow in the tee then 20% of the body area

ill be used in the size change calculation. The use of the Partialoption has the effect of increasing the

pressure loss calculated by simple fixed K factors.

the flash, thethe vapor outlet will have no flow.

instability in the pressure solution of the whole network. Tocreates an arbitrary vapor phase with

can specify the

Page 61: Flarenet modelling

5 Nodes

Design Tab

Fig 5.12

Field

Min Drop Diameter

Drain Volume

Maximum Holdup time

Design Length

Settling Velocity

Summary Tab

The result of the calculations at each of the pipe connections is displayed.

Design Tab

Description

Min Drop Diameter Enter the diameter of the minimum drop size to beremoved.

Enter the drain volume.

Maximum Holdup time Enter maximum holdup time before the horizontalseparator will be drained.

Minimum length of the horizontal separator required tosatisfy design conditions.

Settling velocity of the minimum drop size to be removed.

Summary Tab

The result of the calculations at each of the pipe connections is displayed.

55

Enter the diameter of the minimum drop size to be

Enter maximum holdup time before the horizontal

ength of the horizontal separator required to

minimum drop size to be removed.

The result of the calculations at each of the pipe connections is displayed.

Page 62: Flarenet modelling

56

Fig 5.13

Orifice PlateAn Orifice Plateperpendicular to the flat upstream face of the plate placed crossways in thepipe. Orifice plates are generally used to restrict the flow downstream of ablow down valve or restrict the flow from a high pressure section of a flaresystem to a low pressure section. They may also be used to allow flowmeasurement.

Connections Tab

The name of the orifice plate and connectivity information is specified here.

Orifice PlateOrifice Plate is a thin plate, which has a clean-cut hole with straight walls

perpendicular to the flat upstream face of the plate placed crossways in thepipe. Orifice plates are generally used to restrict the flow downstream of ablow down valve or restrict the flow from a high pressure section of a flareystem to a low pressure section. They may also be used to allow flow

Connections Tab

The name of the orifice plate and connectivity information is specified here.

5 Nodes

ole with straight wallsperpendicular to the flat upstream face of the plate placed crossways in thepipe. Orifice plates are generally used to restrict the flow downstream of ablow down valve or restrict the flow from a high pressure section of a flareystem to a low pressure section. They may also be used to allow flow

The name of the orifice plate and connectivity information is specified here.

Page 63: Flarenet modelling

5 Nodes

Fig 5.14

The following fields are available on this tab:

Field

Name

Location

Upstream/Downstream

At

Ignore

Calculations Tab

Calculation methods are specified here.

The following fields are available on this tab:

Description

The alphanumeric description of the Orifice PlateHP OP).

You may want to specify the location of theplant.

Upstream/Downstream Either type in the name of the pipe segment or select fromthe list.

You can specify the end of the pipe segment attached tothe orifice plate.

Select the Ignore check box to ignore this orificethe calculations. Clear the check box to re-

Calculations Tab

Calculation methods are specified here.

57

Orifice Plate (e.g. -

You may want to specify the location of the node in the

Either type in the name of the pipe segment or select from

e end of the pipe segment attached to

box to ignore this orifice plate in-enable it.

Page 64: Flarenet modelling

58

Fig 5.15

Note: You only need to provide 1 of 3 sizing parameters. For Example, if youentered the DiameterUpstream Diameter Ratio

The following fields are available on this tab:

Field Description

Dimensions Group

Diameter

UpstreamDiameter Ratio

DownstreamDiameter Ratio

Methods Group

Fitting LossMethod

The following options

ou only need to provide 1 of 3 sizing parameters. For Example, if youDiameter, Aspen Flare System Analyzer will then

Upstream Diameter Ratio and the Downstream Diameter Ratio

The following fields are available on this tab:

Description

Dimensions Group

The diameter of the orifice hole.

The ratio of the throat diameter to the upstream pipe diameter.

The ratio of the throat diameter to the downstream pipe diameter

The following options are available:

Ignored - If this option is selected, the fitting losses for theorifice plate would not be calculated. Static pressure isbalanced.

Thin Orifice - The fitting losses for the orifice plate will becalculated using the equations for the thin orifice plate.

Contraction/Expansion - For this method, orifice plates will bemodeled as a sudden contraction from the inlet line size tothe diameter of the hole followed by a sudden expansionthe diameter of the hole to the outlet line size.

5 Nodes

ou only need to provide 1 of 3 sizing parameters. For Example, if youthen calculate the

Downstream Diameter Ratio.

ratio of the throat diameter to the upstream pipe diameter.

he ratio of the throat diameter to the downstream pipe diameter.

If this option is selected, the fitting losses for theorifice plate would not be calculated. Static pressure is

ice plate will becalculated using the equations for the thin orifice plate.

For this method, orifice plates will bemodeled as a sudden contraction from the inlet line size tothe diameter of the hole followed by a sudden expansion fromthe diameter of the hole to the outlet line size.

Page 65: Flarenet modelling

5 Nodes 59

Field Description

IsothermalPressureDrop

If this option is set to Yes, the inlet temperatures used for the sizechange calculations in the orifice plate will not update during iterativecalculations for pressure loss i.e. a PT flash will be used to update theinlet properties. If the option is set to No, a more rigorous PH flashwill be used to update the inlet properties.

The orifice plate will do one contraction calculation and one expansioncalculation if the Fitting Loss Method is set toContraction/Expansion. Setting this option to Yes can speed upcalculations in some cases at cost of a minor loss of accuracy.

Size Change Group

Two PhaseCorrection

If this option is set to Yes, the pressure loss coefficient in two phaseflow will be calculated using properties corrected for liquid slip. If setto No, the homogeneous properties of the fluid will be used incalculating the pressure loss coefficient.

Method The following options are available:

Compressible - Pressure losses will be calculated assumingcompressible flow through the connector at all times.

Incompressible (Crane) - Pressure losses will be calculatedassuming incompressible flow through the connector at alltimes. Loss coefficients are calculated using Cranecoefficients.

Transition - Pressure losses will be calculated initially usingthe assumption of incompressible flow. If the pressure lossexpressed as a percentage of the inlet pressure is greaterthan the defined compressible transition value then thepressure drop will be recalculated using the compressible flowmethod.

Incompressible (HTFS) - Pressure losses will be calculatedassuming incompressible flow through the connector at alltimes. Loss coefficients are calculated using HTFScorrelations.

The Incompressible method calculations are faster but will be lessaccurate at higher pressure drops. The Transition method can causeinstabilities in some cases if the calculated pressure drop is close tothe transition value.

Balance Total Pressure – Frictional pressure drop is ignoredand total pressure is balanced between upstream &downstream.

CompressibleTransition

This entry defines the pressure drop as a percentage of the inletpressure at which compressible flow pressure drop calculationsshould be used. It applies only when the Transition method isselected.

Page 66: Flarenet modelling

60

Summary Tab

Fig 5.16

The result of the calculations at each of the pipe connections is displayed.

TeeThe Tee is used to model the connection of three pipespipes may be different.

Connections Tab

The name of the tee and connectivity information is specified here.

Summary Tab

The result of the calculations at each of the pipe connections is displayed.

is used to model the connection of three pipes. The diameters of thepipes may be different.

Connections Tab

The name of the tee and connectivity information is specified here.

5 Nodes

The result of the calculations at each of the pipe connections is displayed.

. The diameters of the

The name of the tee and connectivity information is specified here.

Page 67: Flarenet modelling

5 Nodes

Fig 5.17

You only need to provide 2 of 3 connections to be able to solve the tee. Thisallows for solution(s) to partially

The following fields are available on this tab:

Field

Name

Location

Upstream/Downstream/Branch

At

Ignore

Calculations Tab

Calculation methods are specified here.

You only need to provide 2 of 3 connections to be able to solve the tee. Thisallows for solution(s) to partially built networks.

The following fields are available on this tab:

Description

The alphanumeric description of theTee 1).

You may want to specify the location of the node inthe plant. The location can have an alphanumername. This feature is useful for large flowsheets,because you can provide a different “location” nameto different sections to make it more comprehensible.

Upstream/Downstream/Branch Either type in the name of the pipe segment or selectfrom the list.

You can specify the end of the pipe segment attachedwith the tee.

Select the Ignore check box to ignore this tee in thecalculations. Clear the check box to re

Calculations Tab

Calculation methods are specified here.

61

You only need to provide 2 of 3 connections to be able to solve the tee. This

The alphanumeric description of the Tee (e.g. - HP

You may want to specify the location of the node inthe plant. The location can have an alphanumericname. This feature is useful for large flowsheets,because you can provide a different “location” nameto different sections to make it more comprehensible.

Either type in the name of the pipe segment or select

You can specify the end of the pipe segment attached

box to ignore this tee in thebox to re-enable it.

Page 68: Flarenet modelling

62

Fig 5.18

The following fields are available on this tab:

Field Description

Dimensions Group

Theta Specify thetee.

Body Specify the diameter of the body of the tee.

Methods Group

e following fields are available on this tab:

Description

Dimensions Group

Specify the angle of the branch to the upstream connectiontee.

Specify the diameter of the body of the tee. Allowable choices are:

Run - The diameter will be that of the inlet pipe.

Tail - The diameter will be that of the outlet pipe.

Branch - The diameter will be that of the branch pipe.

Auto - Set the body diameter to be larger of the inlet andbranch pipe diameters.

5 Nodes

connection of the

Allowable choices are:

ill be that of the inlet pipe.

he diameter will be that of the outlet pipe.

he diameter will be that of the branch pipe.

the body diameter to be larger of the inlet and

Page 69: Flarenet modelling

5 Nodes 63

Field Description

Fitting LossMethod

The available options are:

Equal Static Pressure – Pressure drop calculation is ignoredand static pressure is balanced.

Simple - This method uses a constant, flow rationindependent K factor for the loss through the branch andrun.

Miller - This method uses a K factor which is interpolatedusing Miller Curves, which are functions of the flow and arearatios of the branch to the total flow as well as the branchangle. Loss coefficients at low values of the branch are tobody area are extrapolated from the data presented on thecharts.

Miller (Area Ratio Limited) – This method uses a K factorwhich is interpolated using Miller Curves, which arefunctions of the flow and area ratios of the branch to thetotal flow as well as the branch angle. The ratio of thebranch area to body area is constrained by the lower limitpresented on the charts.

Equal Static Pressure – Pressure drop calculation is ignoredand static pressure is balanced.

Gardel – This method calculates the K factor using theanalytical equations of Gardel.

Miller ChartExtrapolation

The available options are:

None – No extrapolation is used. If the data falls outside theMiller chart, a fixed value of K (K=8.0) is used.

Miller Area Ratio Squared – Uses a K factor which isextrapolated using Miller Curves, assuming that the Kfactors are functions of the flow and area ratio squared, ofthe branch to the total flow as well as the branch angle.

Gardel – Uses the Gardel method to calculate K factor if theK factor is out of bounds in miller chart.

Connector IfIncomplete

If this option is set to Yes, Aspen Flare System Analyzer will treatthe Tee as a straight connector, ignoring the effect of the branch onpressure drop.

The Tee will do three size change calculations between inlet/body,branch/body and body/outlet selecting expansion or contractioncalculations as appropriate.

Setting this option to Yes can speed up calculations in some casesat cost of a minor loss of accuracy.

IsothermalPressure Drop

If this option is set to Yes, the inlet temperatures used for the sizechange calculations in the tee will not update during iterativecalculations for pressure loss, i.e. a PT flash will be used to updatethe inlet properties. If the option is set to No, a more rigorous PHflash will be used to update the inlet properties.

Swage Method Group

Two PhaseCorrection

If this option is set to Yes, the pressure loss coefficient in two phaseflow will be calculated using properties corrected for liquid slip. If setto No, the homogenous properties of the fluid will be used incalculating the pressure loss coefficient.

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64 5 Nodes

Field Description

Method The following options are available:

Compressible - Pressure losses will be calculated assumingcompressible flow through the tee at all times.

Incompressible (Crane) - Pressure losses will be calculatedassuming incompressible flow through the tee at all times.Loss coefficients are calculated using Crane coefficients.

Transition - Pressure losses will be calculated initially usingthe assumption of incompressible flow. If the pressure lossexpressed as a percentage of the inlet pressure is greaterthan the defined compressible transition value then thepressure drop will be recalculated using the compressibleflow method.

Incompressible (HTFS) - Pressure losses will be calculatedassuming incompressible flow through the tee at all times.Loss coefficients are calculated using HTFS correlations.

The Incompressible method calculations are faster but will be lessaccurate at higher pressure drops. The Transition method cancause instabilities in some cases if the calculated pressure drop isclose to the transition value.

Balance Total Pressure – Frictional pressure drop is ignoredand total pressure is balanced between upstream &downstream.

CompressibleTransition

This entry defines the pressure drop as a percentage of the inletpressure at which compressible flow pressure drop calculationsshould be used. It applies only when the Transition method isselected.

BodyDimension

If this option is set to Full Body Area, the calculation for theinlet/body and branch/body size change will use the whole bodyarea. If Partial Body Area on Flow is selected, the body area isreduced in proportion to the appropriate flow, i.e. if the branchvolumetric flow is 20% of the total volumetric flow in the tee then20% of the body area will be used in the size change calculation.This option is ignored if the fittings loss method is set to Miller. Theuse of the Partial Body Area on Flow option has the effect ofincreasing the pressure loss calculated by simple fixed K factorsbringing the results closer to those calculated by the ore accurateMiller K factors.

Summary Tab

The result of the calculations at each of the pipe connections is displayed.

Page 71: Flarenet modelling

5 Nodes

Fig 5.19

Vertical SeparatorVertical separators are used to allow liquid to separate from the feed streamso that it can be removed from the flare system. The liquid phase in thevertical separator feed is removed from the network. In Aspen Flare SystemAnalyzer, the Vertical Separatorstream.

Connections Tab

The name of the vertical separator and connectivity information is specifiedhere.

Vertical Separatoreparators are used to allow liquid to separate from the feed stream

so that it can be removed from the flare system. The liquid phase in theeparator feed is removed from the network. In Aspen Flare System

Vertical Separator has only one inlet and one vapor outlet

Connections Tab

The name of the vertical separator and connectivity information is specified

65

eparators are used to allow liquid to separate from the feed streamso that it can be removed from the flare system. The liquid phase in the

eparator feed is removed from the network. In Aspen Flare Systemhas only one inlet and one vapor outlet

The name of the vertical separator and connectivity information is specified

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66

Fig 5.20

The location can have an alphanumeric name. This feature is useful forflowsheets, because you can provide a different “location” name to differentsections to make it more comprehensible.

The following fields are available on this tab:

Field Description

Name The alphanumeric description of theDrum).

Location You may want to specify the location of the

Inlet/Outlet Either type in the name of the pipe segment or select from the list.

At You can specify the end of the pipe segment attached to theseparato

Ignore Select thecalculations. Clear the check

Calculations Tab

Calculation methods are specified here.

The location can have an alphanumeric name. This feature is useful forflowsheets, because you can provide a different “location” name to differentsections to make it more comprehensible.

The following fields are available on this tab:

Description

The alphanumeric description of the Vertical SeparatorDrum).

You may want to specify the location of the node in the plant.

Either type in the name of the pipe segment or select from the list.

You can specify the end of the pipe segment attached to theeparator.

Select the Ignore check box to ignore this vertical separator in thecalculations. Clear the check box to re-enable it.

Calculations Tab

Calculation methods are specified here.

5 Nodes

The location can have an alphanumeric name. This feature is useful for largeflowsheets, because you can provide a different “location” name to different

Vertical Separator (e.g. - HP KO

in the plant.

Either type in the name of the pipe segment or select from the list.

You can specify the end of the pipe segment attached to the vertical

box to ignore this vertical separator in the

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5 Nodes

Fig 5.21

The following fields are available on this tab:

Field D

Diameter The internal diameter of the vessel.

Methods Group

Fitting LossMethod

The available options are:

IsothermalPressure Drop

If this optiochange calculations in the separator will not update during iterativecalculations for pressure loss i.e. a PT flash will be used to updatethe inlet properties. If the option is set toflash will be used to update the inlet properties.

The vertical separator will do one expansion calculation for the inletstream entering the vessel and one contraction calculation for theflow from the vessel to the outlet. These will automaticflows through the vessel are reversed.

Setting this option toat cost of a minor loss of accuracy.

Size Change Group

The following fields are available on this tab:

Description

The internal diameter of the vessel.

The available options are:

Equal Static Pressure – Pressure drop calculation is ignoredand static pressure is balanced.

Calculated Ignore Vena Contracta – Pressure drop iscalculated in accordance with the Swage method butignores the loss due vena contracta.

Calculated – Pressure drop is calculated in accordance withthe Swage method including the loss due vena contracta.

If this option is set to Yes, the inlet temperatures used for the sizechange calculations in the separator will not update during iterativecalculations for pressure loss i.e. a PT flash will be used to updatethe inlet properties. If the option is set to No, a more rflash will be used to update the inlet properties.

The vertical separator will do one expansion calculation for the inletstream entering the vessel and one contraction calculation for theflow from the vessel to the outlet. These will automaticflows through the vessel are reversed.

Setting this option to Yes can speed up calculations in some casesat cost of a minor loss of accuracy.

Size Change Group

67

Pressure drop calculation is ignored

sure drop ismethod but

Pressure drop is calculated in accordance withmethod including the loss due vena contracta.

, the inlet temperatures used for the sizechange calculations in the separator will not update during iterativecalculations for pressure loss i.e. a PT flash will be used to update

a more rigorous PH

The vertical separator will do one expansion calculation for the inletstream entering the vessel and one contraction calculation for theflow from the vessel to the outlet. These will automatically change if

can speed up calculations in some cases

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68 5 Nodes

Field Description

Two PhaseCorrection

If this option is set to Yes, the pressure loss coefficient in two phaseflow will be calculated using properties corrected for liquid slip. If setto No, the homogenous properties of the fluid will be used incalculating the pressure loss coefficient.

Method The following options are available:

Compressible - Pressure losses will be calculated assumingcompressible flow through the connector at all times.

Incompressible (Crane) - Pressure losses will be calculatedassuming incompressible flow through the connector at alltimes. Loss coefficients are calculated using Cranecoefficients.

Transition - Pressure losses will be calculated initially usingthe assumption of incompressible flow. If the pressure lossexpressed as a percentage of the inlet pressure is greaterthan the defined compressible transition value then thepressure drop will be recalculated using the compressibleflow method.

Incompressible (HTFS) - Pressure losses will be calculatedassuming incompressible flow through the connector at alltimes. Loss coefficients are calculated using HTFScorrelations.

The Incompressible method calculations are faster but will be lessaccurate at higher pressure drops. The Transition method cancause instabilities in some cases if the calculated pressure drop isclose to the transition value.

Balance Total Pressure – Frictional pressure drop is ignoredand total pressure is balanced between upstream &downstream.

CompressibleTransition

This entry defines the pressure drop as a percentage of the inletpressure at which compressible flow pressure drop calculationsshould be used. It applies only when the Transition method isselected.

Composition Tab

If the inlet feed flashes in the separator, as a result of the flash, the mixtureis converted into liquid fully and the vapor outlet will have no flow. This cancause instability in the pressure solution of the whole network. To avoid this,Aspen Flare System Analyzer creates an arbitrary vapor phase with very smallvapor fraction for the vapor outlet (<0.001%). You can specify thecomposition of the vapor phase here.

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5 Nodes

Fig 5.22

69

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70

Design Tab

Fig 5.23

Field

Min Drop Diameter

Design Diameter

Settling Velocity

Summary Tab

The result of the calculations at each of the pipe connections is displayed.

Design Tab

Description

Min Drop Diameter Enter the diameter of the minimum drop size to beremoved.

Minimum diameter of the vertical separator required tosatisfy design conditions.

Settling velocity of the minimum drop size to be removed.

Summary Tab

The result of the calculations at each of the pipe connections is displayed.

5 Nodes

Enter the diameter of the minimum drop size to be

Minimum diameter of the vertical separator required to

elocity of the minimum drop size to be removed.

The result of the calculations at each of the pipe connections is displayed.

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5 Nodes

Fig 5.24

Boundary NodesThe following types of boundary nodes are available in Aspen Flare SystemAnalyzer. A bounda

Control Valve

Relief Valve

Flare Tip

The relief valve and control valve node types represent sources or inflows intothe system. Thealternative types of sourcespurge valves.

Control ValveThe Control Valvevalves, bursting disks and blow down valves. The most significant differenceto the Relief Valve

Connections Tab

The name of the control valve and connectivity information is specified here.

Boundary NodesThe following types of boundary nodes are available in Aspen Flare SystemAnalyzer. A boundary node is one that is connected to only one pipe segment.

Control Valve

Relief Valve

The relief valve and control valve node types represent sources or inflows intothe system. The Control Valve, in particular, may also be used to model

ive types of sources, such as blow down valves, rupture disks, and

Control ValveControl Valve is used to model a constant flow source, such as purge

ting disks and blow down valves. The most significant differenceRelief Valve is that the rated flow equals the nominal flow.

Connections Tab

The name of the control valve and connectivity information is specified here.

71

The following types of boundary nodes are available in Aspen Flare Systemry node is one that is connected to only one pipe segment.

The relief valve and control valve node types represent sources or inflows into, in particular, may also be used to model

rupture disks, and

such as purgeting disks and blow down valves. The most significant difference

is that the rated flow equals the nominal flow.

The name of the control valve and connectivity information is specified here.

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72

Fig 5.25

The location can hflowsheets, because you can provide a different “location” name to differentsections to make it more comprehensible.

The following fields are available on this tab:

Field Description

Name The al

Location You may want to specify the location of the

Outlet Either type in the name of the pipe segment or select from the list.

At You can specify where the pipe segment isvalve.

Ignore Select thecalculations. Clear the check

Conditions Tab

Fluid conditions are specified here.

The location can have an alphanumeric name. This feature is useful for largeflowsheets, because you can provide a different “location” name to differentsections to make it more comprehensible.

The following fields are available on this tab:

Description

The alphanumeric description of the Control Valve (e.g.

You may want to specify the location of the node in the plant.

Either type in the name of the pipe segment or select from the list.

You can specify where the pipe segment is to be attached to thealve.

Select the Ignore check box to ignore this control valve in thecalculations. Clear the check box to re-enable it.

Conditions Tab

Fluid conditions are specified here.

5 Nodes

ave an alphanumeric name. This feature is useful for largeflowsheets, because you can provide a different “location” name to different

(e.g. - FCV 1).

in the plant.

Either type in the name of the pipe segment or select from the list.

to be attached to the control

box to ignore this control valve in the

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5 Nodes

Fig 5.26

It is recommended that a valueto an isenthalpic flash from the upstream conditions down to theBack Pressure. This will give the highest probable entry temperature intothe system which will in turn give the highest velocities.

The following fields are available on this tab:

Field Description

Conditions Group

Inlet Pressure

Inlet Temp.Spec.

It is recommended that a value for Outlet Temperature which correspondsto an isenthalpic flash from the upstream conditions down to the

. This will give the highest probable entry temperature intothe system which will in turn give the highest velocities.

lowing fields are available on this tab:

Description

Conditions Group

The pressure of the source on the upstream side of the valve.

The temperature specification of the source on the upsof the control valve. You can select the fluid condition from the liston the left side. The available options are:

Actual - The given inlet temperature is the actual fluidtemperature.

Superheat - If this option is selected, enter the amount ofsuperheat.

Subcool - If this option is selected, enter the amount ofsubcooling.

73

which correspondsto an isenthalpic flash from the upstream conditions down to the Allowable

. This will give the highest probable entry temperature into

The pressure of the source on the upstream side of the valve.

The temperature specification of the source on the upstream sideYou can select the fluid condition from the list

The given inlet temperature is the actual fluid

If this option is selected, enter the amount of

s option is selected, enter the amount of

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74 5 Nodes

Field Description

Allowable BackPressure

The Allowed Back Pressure is the pressure that is allowed toexist at the outlet of a pressure relief device as a result of thepressure in the discharge system. It is the sum of thesuperimposed and built-up back pressure. Clicking Set calculatesthe Allowable Back Pressure as a function of the InletPressure. Selecting the Auto check box will automaticallycalculate the Allowable Back Pressure whenever the InletPressure changes.

OutletTemperature

This is the temperature of the source at the flange on thedownstream side of the valve.

If the enthalpy method chosen is the Ideal Gas model, thistemperature is used to determine the enthalpy of the source at theentrance to the pipe network; otherwise, this enthalpy is calculatedfrom the upstream pressure and temperature. If Set was clicked,and the enthalpy model is Peng Robinson, Soave RedlichKwong or Lee Kesler, the outlet temperature will be calculatedfrom the upstream temperature and pressure after isenthalpicexpansion to the defined Allowable Back Pressure.

Mass Flow This is the mass flow of the source. This is generally the flow rategenerated by the upset condition.

Dimensions Group

FlangeDiameter

This is the diameter of the flange at the valve discharge. The flangediameter may be left unknown in which case it will be assumed to bethe same as the outlet pipe.

Composition Tab

The fluid composition is specified here.

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5 Nodes

Fig 5.27

The following fields are available on

Field Description

Basis TMole Fraction

Mol. Wt. Thethe composition basis selected is

If the composition basis selected isFractionchange the component fractions.

Fluid Type Ifto calculate a binaryweight. If the two components of the specified fluid type are notfound

ComponentFractions

The fluid composition in either mole or mass fractions. You can onlyenter data here iffractions. You can normalize the composition either manually editingthe component fractions or by clicking

If the compositioncomponent fractions are estimaweight.

The following fields are available on this tab:

Description

The composition basis, which may be either MolecularMole Fraction or Mass Fraction.

The molecular weight of the fluid. You can only enter data here ifthe composition basis selected is molecular weight.

If the composition basis selected is Mole FractionFraction, the molecular weight is updated when you enter orchange the component fractions.

If molecular weight is selected , you need to select theto calculate a binary composition in order to match the molecularweight. If the two components of the specified fluid type are notfound, the other components are used.

The fluid composition in either mole or mass fractions. You can onlyenter data here if the composition basis selected is mole or massfractions. You can normalize the composition either manually editingthe component fractions or by clicking Normalise.

If the composition Basis selected is molecular weight, thecomponent fractions are estimated when you change the molecularweight.

75

ecular Weight,

molecular weight of the fluid. You can only enter data here if.

or Mass, the molecular weight is updated when you enter or

you need to select the Fluid Typecomposition in order to match the molecular

weight. If the two components of the specified fluid type are not

The fluid composition in either mole or mass fractions. You can onlythe composition basis selected is mole or mass

fractions. You can normalize the composition either manually editing

selected is molecular weight, theted when you change the molecular

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76

Field Description

CloneCompositionFrom

This button allows the copying of compositional data from anothercontrol

Normalise Normalises the composition such that the sum of the componentfractions is 1.

Methods Tab

Calculation methods are specified here.

Fig 5.28

The following fields are available on this tab:

Fields Description

Description

This button allows the copying of compositional data from anothercontrol valve in the same scenario.

Normalises the composition such that the sum of the componentfractions is 1.

Methods Tab

Calculation methods are specified here.

The following fields are available on this tab:

Description

5 Nodes

This button allows the copying of compositional data from another

Normalises the composition such that the sum of the component

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5 Nodes 77

Fields Description

VLE Method The options for the Vapor-Liquid Equilibrium calculations are asfollows (see Chapter 9 Theoretical Basis):

Compressible Gas – Real Gas relationship. This is onlyavailable when the Enthalpy Method on the CalculationOptions Editor is Ideal Gas.

Peng Robinson – Peng Robinson Equation of State. This isonly available when the Enthalpy Method on theCalculation Options Editor is NOT Ideal Gas.

Soave Redlich Kwong – Soave Redlich Kwong Equation ofState. This is only available when the Enthalpy Method onthe Calculation Options Editor is NOT Ideal Gas.

Vapour Pressure – Vapour Pressure method as described inAPI Technical Data Book– Volume 113. This is only availablewhen the Enthalpy Method on the Calculation OptionsEditor is NOT Ideal Gas.

Model Default - If this is selected, the Default method forthe VLE method (as defined on the Calculation OptionsEditor) will be used.

Swage Group

Fitting LossMethod

The available options are;

Equal Static Pressure – Pressure drop calculation is ignoredand static pressure is balanced.

Calculated – Pressure drop is calculated in accordance withthe Swage method.

IsothermalPressure Drop

If this option is set to Yes, the inlet temperatures used for the sizechange calculations in the control valve will not update duringiterative calculations for pressure loss i.e. a PT flash will be used toupdate the inlet properties. If the option is set to No, a morerigorous PH flash will be used to update the inlet properties.

The control valve will do one size change calculation from thedefined flange diameter to the outlet pipe diameter. This willnormally be an expansion.

Setting this option to Yes can speed up calculations in some casesat cost of a minor loss of accuracy.

Two PhaseCorrection

If this option is set to Yes, the pressure loss coefficient in two phaseflow will be calculated using properties corrected for liquid slip. If setto No, the homogeneous properties of the fluid will be used incalculating the pressure loss coefficient.

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78 5 Nodes

Fields Description

Method The following options are available:

Compressible - Pressure losses will be calculated assumingcompressible flow through the connector at all times.

Incompressible (Crane) - Pressure losses will be calculatedassuming incompressible flow through the connector at alltimes. Loss coefficients are calculated using Cranecoefficients.

Transition - Pressure losses will be calculated initially usingthe assumption of incompressible flow. If the pressure lossexpressed as a percentage of the inlet pressure is greaterthan the defined compressible transition value then thepressure drop will be recalculated using the compressibleflow method.

Incompressible (HTFS) - Pressure losses will be calculatedassuming incompressible flow through the connector at alltimes. Loss coefficients are calculated using HTFScorrelations.

The Incompressible method calculations are faster but will be lessaccurate at higher pressure drops. The Transition method cancause instabilities in some cases if the calculated pressure drop isclose to the transition value.

Balance Total Pressure – Frictional pressure drop is ignoredand total pressure is balanced between upstream &downstream.

CompressibleTransition

This entry defines the pressure drop as a percentage of the inletpressure at which compressible flow pressure drop calculationsshould be used. It applies only when the Transition method isselected.

Estimated Properties at Header Conditions Group

VapourFraction

The initial estimates for the flow profile in looped systems aregenerated based on the assumption of vapor phase flow without anyliquid knockout in the system. It is not uncommon for sources topass through a knockout drum before connection to the mainheader. Specification of an estimate of vapor fraction of the fluid atthe knockout drum can considerably enhance the automaticallygenerated flow profile. If not specified, for the initial estimates, thefluid is assumed to be vapor only at the header condition.

Vapour Mol.Wt.

Specify the estimated vapor molecular weight for the vapor fractiongiven above. If provided, this value is used to assist the automaticgeneration of the flow profile for looped systems. If not specified, forthe initial estimates, the vapour molecular weight is assumed to bethe same as the overall fluid molecular weight at the headercondition.

Inlet Piping Tab

Details of the piping between the protected equipment and the inlet to thecontrol valve are specified here. This data is used to calculate the pressuredrop in the inlet piping. The diameter of the inlet piping is also used tocalculate the inlet velocity of the source fluid when the Include KineticEnergy option is selected in the Calculation Options Editor.

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5 Nodes

Fig 5.29

The available fields are:

Fields Description

Routing Group

Length The length of the inlet piping.

ElevationChange

The change in elevation of the inlet piping. Ththan the length of the piping.

Properties Group

Material The material of the inlet pipeSteel

Roughness The surface roughness of the inlet pipe. Whenever a material isselected, the absolute roughnthe material as defined on the

Diameter Group

NominalDiameter

The nominal pipe diameter used to describe the inlet pipe size. Forpipes with a nominal diameter of 14 inches or more, this wisame as the outside diameter of the pipe.

Schedule If a pipe schedule is selected, you will be able to select a nominal pipediameter from the pipe databases. It will not be necessary to specifythe internal diameter.

The available fields are:

Description

The length of the inlet piping.

The change in elevation of the inlet piping. This cannot be greaterthan the length of the piping.

Properties Group

The material of the inlet pipe, either Carbon Steel orSteel.

The surface roughness of the inlet pipe. Whenever a material isselected, the absolute roughness is initialized to the default value forthe material as defined on the Preferences Editor.

Diameter Group

The nominal pipe diameter used to describe the inlet pipe size. Forpipes with a nominal diameter of 14 inches or more, this wisame as the outside diameter of the pipe.

If a pipe schedule is selected, you will be able to select a nominal pipediameter from the pipe databases. It will not be necessary to specifythe internal diameter.

79

is cannot be greater

or Stainless

The surface roughness of the inlet pipe. Whenever a material isess is initialized to the default value for

The nominal pipe diameter used to describe the inlet pipe size. Forpipes with a nominal diameter of 14 inches or more, this will be the

If a pipe schedule is selected, you will be able to select a nominal pipediameter from the pipe databases. It will not be necessary to specify

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80

Fields Description

InternalDiameter

The pipe

Use PipeClass

Selectdefined by the

Fittings Groups

LossCoefficient

Enter the A and B parameters for the following fittequation in which Fflow:

K = A +

Summary Tab

The result of the calculations is displayed.

Fig 5.30

Description

The pipe diameter used for the pressure drop calculations.

Select Yes to restrict the sizes of the inlet piping selected to thosedefined by the Pipe Class tool.

Enter the A and B parameters for the following fittings K factorequation in which Ft is the friction factor for fully developed turbulentflow:

K = A + BFt

Summary Tab

The result of the calculations is displayed.

5 Nodes

diameter used for the pressure drop calculations.

to restrict the sizes of the inlet piping selected to those

ings K factoris the friction factor for fully developed turbulent

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5 Nodes

Relief ValveThe Relief Valve source can be used to model types of spring loaded reliefvalves. Relief valves are used frequently in many industries in order toprevent dangerous situations occurring from pressure build

Connections Tab

The name of the relief valve and connectivity information is specified here.

Fig 5.31

The location can have an alphanumeric name. This feature is useful for largeflowsheets, because you can provide a different “location” name to differentsections to make it

ief Valvesource can be used to model types of spring loaded relief

valves. Relief valves are used frequently in many industries in order toprevent dangerous situations occurring from pressure build-ups in a system.

Connections Tab

ame of the relief valve and connectivity information is specified here.

The location can have an alphanumeric name. This feature is useful for largeflowsheets, because you can provide a different “location” name to differentsections to make it more comprehensible.

81

source can be used to model types of spring loaded reliefvalves. Relief valves are used frequently in many industries in order to

ups in a system.

ame of the relief valve and connectivity information is specified here.

The location can have an alphanumeric name. This feature is useful for largeflowsheets, because you can provide a different “location” name to different

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82 5 Nodes

The following fields are available on this tab:

Field Description

Name The alphanumeric description of the Relief Valve (e.g. - FCV 1).

Location You may want to specify the location of the node in the plant.

Outlet Either type in the name of the pipe segment or select from the list.

At You can specify where the pipe segment is to be attached to the reliefvalve.

Ignore Select the Ignore check box to ignore this relief valve in thecalculations. Clear the check box to re-enable it.

Conditions Tab

Fluid conditions are specified here.

Page 89: Flarenet modelling

5 Nodes

Fig 5.32

It is recommended that a value forto an isenthalpic flash from the upstream conditions down to theBack Pressure. This will give the highestthe system which will in turn give the highest velocities.

The following fields are available on this tab:

Field

Conditions Group

MAWP

It is recommended that a value for Outlet Temperature which correspondsto an isenthalpic flash from the upstream conditions down to the

. This will give the highest probable entry temperature intothe system which will in turn give the highest velocities.

The following fields are available on this tab:

Description

Conditions Group

The Maximum Allowable Working Pressure (MAWPmaximum gauge pressure permissible in a vessel at its operatingtemperature. It is normally equal to the relief valve set pressureunless you have a low pressure vessel.

83

which correspondsto an isenthalpic flash from the upstream conditions down to the Allowable

probable entry temperature into

MAWP) is thee permissible in a vessel at its operating

temperature. It is normally equal to the relief valve set pressure

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84 5 Nodes

Field Description

Contingency In general there are two types of process upset conditions:

Operating - The relieving pressure is 110% of MAWPunless you have a multiple valve assembly in which case itis 116% of MAWP. Some of the operating upset examplesare cooling failure, power failure and instrument air failure.

Fire - The relieving pressure is 121% of MAWP.

RelievingPressure

The Relieving Pressure is equal to the valve set pressure plus theoverpressure. You can either enter the value or have it calculatedusing the MAWP and the Contingency by clicking Set. If youentered a value less than the MAWP, a warning message will begenerated.

Selection of the Auto check box will automatically calculated therelieving pressure from the MAWP and Contingency wheneverthese values change.

Inlet Temp.Spec.

The temperature specification of the source on the upstream side ofthe relief valve. You can select the fluid condition from the dropdown box on the right hand side of this field. The available optionsare:

Actual - It uses the given inlet temperature as the actualfluid temperature.

Superheat - If this option is selected, enter the amount ofsuperheat.

Subcool - If this option is selected, enter the amount ofsubcooling.

Allowable BackPressure

The Allowable Back Pressure is the pressure that is allowed toexist at the outlet of a pressure relief device as a result of thepressure in the discharge system. It is the sum of thesuperimposed and built-up back pressure. Clicking Set calculatesthe Allowable Back Pressure as a function of the valve type andMAWP.

If the Auto check box is selected then the allowed back pressure isautomatically updated whenever the valve type or MAWP ischanged.

OutletTemperature

This is the temperature of the source on the downstream side ofthe valve.

If the enthalpy method chosen is the Ideal Gas model, then thistemperature is used to determine the enthalpy of the source at theentrance to the pipe network, otherwise this enthalpy is calculatedby isenthalpic flash from the upstream pressure and temperature.

If Set is pressed and the enthalpy model is Peng Robinson,Soave Redlich Kwong or Lee Kesler, the outlet temperature willbe calculated from the upstream temperature and pressure afterexpansion to the defined Allowable Back Pressure.

Mass Flow The nominal mass flow of the source. This is generally the flowrategenerated by the upset condition.

Rated Flow It is the rated mass flow of the source. This is generally theflowrate that the relief valve is capable of passing.

Clicking Set calculates the rated flow from the MAWP, valve type,orifice area, valve count, upstream pressure, upstream temperatureand sizing method. If the Auto check box is selected, the ratedflow will be automatically updated after any change in these values.

Rated Flow Parameters

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5 Nodes 85

Field Description

K(Cp/Cp-R) K is the Ideal Gas ratio of specific heats.

Compressibility Compressibility Factor for the deviation of the actual gas from aperfect gas evaluated at inlet conditions. (Z= PV/MRT)

Valve Design Group

FlangeDiameter

The diameter of the valve discharge flange. The flange diametermay be left unknown in which case it will be assumed to be thesame as the outlet pipe.

Number ofValves

Specify the number of valves for the source.

Orifice AreaPer Valve

The orifice area per valve may be set by selecting the orifice sizecode from the list. The corresponding orifice area will then bedisplayed. If the size code is set to the blank entry, the orifice areaper valve may be entered manually.

Valve Type The choices are:

Balanced - A spring loaded pressure relief valve thatincorporates a means for minimizing the effect of backpressure on the performance characteristics.

Conventional - A spring loaded pressure relief valve whoseperformance characteristics are directly affected by changesin the back pressure on the valve.

Pilot - A pilot-operated pressure relief valve in which thepilot is a self-actuated device. The major relieving device iscombined with and is controlled by the pilot.

Mech. BP Limit The maximum mechanical back pressure that can be applied to thevalve.

Composition Tab

The fluid composition is specified here.

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86

Fig 5.33

The following fields are available on this tab:

Field Description

Basis The composition basis, which may be eitherFraction

Mol. Wt. The molecular weight of the fluid. You can only enter data here if thecompositi

If the composition basis selected isthe molecular weight is updated when you enter or change thecomponent fractions.

Fluid Type If Molecular Weight is selected in the composition basselect thematch the molecular weight. If the two components of the specified fluidtype are not found

e following fields are available on this tab:

Description

The composition basis, which may be either MolecularFraction or Mass Fraction.

he molecular weight of the fluid. You can only enter data here if thecomposition basis selected is Molecular Weight.

If the composition basis selected is Mole Fraction orthe molecular weight is updated when you enter or change thecomponent fractions.

If Molecular Weight is selected in the composition basselect the Fluid Type to calculate a binary composition in order tomatch the molecular weight. If the two components of the specified fluidtype are not found, the other components are used.

5 Nodes

ecular Weight, Mole

he molecular weight of the fluid. You can only enter data here if the

or Mass Fraction,the molecular weight is updated when you enter or change the

If Molecular Weight is selected in the composition basis list, you need toto calculate a binary composition in order to

match the molecular weight. If the two components of the specified fluid

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5 Nodes 87

Field Description

ComponentFractions

The fluid composition in either mole or mass fractions. You can onlyenter data here if the composition basis selected is mole or massFraction. You can normalize the composition by either manually editingthe component fractions or by clicking Normalise.

If the composition basis selected is Molecular Weight, the componentfractions are estimated when you change the molecular weight.

CloneCompositionFrom

This button allows the copying of compositional data from another reliefvalve in the same scenario.

Normalise Normalises the composition such that the sum of the componentfractions is 1.

Methods Tab

Calculation methods are specified here.

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88

Fig 5.34

The following fields are available on this tab:

Field

The following fields are available on this tab:

Description

5 Nodes

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5 Nodes 89

Field Description

VLE Method The options for the Vapor-Liquid Equilibrium calculations are asfollows (see Chapter 9 Theoretical Basis):

Compressible Gas – Real Gas relationship. This is onlyavailable when the Enthalpy Method on the CalculationOptions Editor is Ideal Gas.

Peng Robinson – Peng Robinson Equation of State. This isonly available when the Enthalpy Method on theCalculation Options Editor is NOT Ideal Gas.

Soave Redlich Kwong – Soave Redlich Kwong Equation ofState. This is only available when the Enthalpy Methodon the Calculation Options Editor is NOT Ideal Gas.

Vapour Pressure – Vapour Pressure method as described inAPI Technical Data Book– Volume 113. This is onlyavailable when the Enthalpy Method on the CalculationOptions Editor is NOT Ideal Gas.

Model Default - If this is selected, the Default method forthe VLE method (as defined on the Calculation OptionsEditor) will be used.

Swage Group

Fitting LossMethod

The available options are;

Equal Static Pressure – Pressure drop calculation is ignoredand static pressure is balanced.

Calculated – Pressure drop is calculated in accordance withthe Swage method.

IsothermalPressure Drop

If this option is set to Yes, the inlet temperatures used for the sizechange calculations in the relief valve will not update duringiterative calculations for pressure loss i.e. a PT flash will be used toupdate the inlet properties. If the option is set to No, a morerigorous PH flash will be used to update the inlet properties.

The relief valve will do one size change calculation from thedefined flange diameter to the outlet pipe diameter. This willnormally be an expansion. Setting this option to Yes can speed upcalculations in some cases at cost of a minor loss of accuracy.

Two PhaseCorrection

If this option is set to Yes, the pressure loss coefficient in twophase flow will be calculated using properties corrected for liquidslip. If set to No, the homogeneous properties of the fluid will beused in calculating the pressure loss coefficient.

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90 5 Nodes

Field Description

Method The following options are available:

Compressible - Pressure losses will be calculated assumingcompressible flow through the connector at all times.

Incompressible (Crane) - Pressure losses will be calculatedassuming incompressible flow through the connector at alltimes. Loss coefficients are calculated using Cranecoefficients.

Transition - Pressure losses will be calculated initially usingthe assumption of incompressible flow. If the pressure lossexpressed as a percentage of the inlet pressure is greaterthan the defined compressible transition value then thepressure drop will be recalculated using the compressibleflow method.

Incompressible (HTFS) - Pressure losses will be calculatedassuming incompressible flow through the connector at alltimes. Loss coefficients are calculated using HTFScorrelations.

The Incompressible method calculations are faster but will beless accurate at higher pressure drops. The Transition methodcan cause instabilities in some cases if the calculated pressuredrop is close to the transition value.

Balance Total Pressure – Frictional pressure drop is ignoredand total pressure is balanced between upstream &downstream.

CompressibleTransition

This entry defines the pressure drop as a percentage of the inletpressure at which compressible flow pressure drop calculationsshould be used. It applies only when the Transition method isselected.

Sizing Method Group

Sizing Method The four sizing method options available are:

API (1976) – American Petroleum Institute method in the1976 edition of RP 520 pt 1. No account is made of liquidflashing as it passes through the relief valve, thus thismethod is not recommended for either two phase orflashing fluids.

API (1993) – American Petroleum Institute method in the1993 edition of RP 520 pt 1. Liquid flashing is handled by asimplified approach in which the fluid is flashed to theoutlet pressure. The relative quantities of each phase atthe outlet condition are then used at the inlet of the valveto determine the two phase capacity

API(2000) – American Petroleum Institute method in the2000 edition of RP 520 pt 1. This method is often referredto as the Diers or Leung method. This is therecommended method for all two phase fluids.

HEM – Homogeneous Equilibrium method.

Back Pressure Back pressure to be used for rating the relief valve. If this value isnot specified, the Allowable Back Pressure is used.

MultiPhase Cd Discharge coefficient to be used of relief valve in multiphaseservice.

Liquid Cd Discharge coefficient to be used for relief valves in liquid service.

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Field Description

Kb User defined back pressure correction factor. If this field is leftblank, the back pressure correction factor is calculated. This valueshould only be specified in exceptional cases.

Energy Balance Group

Isentropic Flash Select Yes to use an isentropic flash between the inlet and outletotherwise an isenthalpic flash will be done.

IsentropicEfficiency

Fractional isentropic efficiency for the isentropic flash.

Estimated Properties at Header Conditions Group

Vapour Fraction The initial estimates for the flow profile in looped systems aregenerated based on the assumption of vapor phase flow withoutany liquid knockout in the system. It is not uncommon for sourcesto pass through a knockout drum before connection to the mainheader. Specification of an estimate of vapor fraction of the fluid atthe knockout drum can considerably enhance the automaticallygenerated flow profile. If provided, this value is used to assist theautomatic generation of the flow profile for looped systems. If notspecified, for the initial estimates, the fluid is assumed to bevapour only at the header condition.

Vapour Mol.Wt.

Specify the estimated vapor molecular weight for the vaporfraction given above. If provided, this value is used to assist theautomatic generation of the flow profile for looped systems. If notspecified, for the initial estimates, the vapour molecular weight isassumed to be the same as the overall fluid molecular weight atthe header condition.

Inlet Piping Tab

Details of the piping between the protected equipment and the inlet to therelief valve are specified here. This data is used to calculate the pressure dropin the inlet piping to ensure that it does not exceed the recommended limit of3% of the inlet pressure. The diameter of the inlet piping is also used tocalculate the inlet velocity of the source fluid when the Include KineticEnergy option is selected in the Calculation Options Editor.

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92

Fig 5.35

The available fields are:

Field Description

Routing Group

Length The length of the

ElevationChange

The change in elevation of the inlet piping. Tthan the

Properties Group

Material The material of the inlet pipeSteel

Roughness The surfaceselected, the absolute roughness is initialized to the default value forthe material as defined on the

Diameter Group

The available fields are:

Description

The length of the inlet piping.

The change in elevation of the inlet piping. This cannot be greaterthan the Length of the piping.

Properties Group

The material of the inlet pipe, either Carbon Steel orSteel.

The surface roughness of the inlet pipe. Whenever a material isselected, the absolute roughness is initialized to the default value forthe material as defined on the Preferences Editor.

Diameter Group

5 Nodes

his cannot be greater

or Stainless

roughness of the inlet pipe. Whenever a material isselected, the absolute roughness is initialized to the default value for

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5 Nodes 93

Field Description

NominalDiameter

The nominal pipe diameter used to describe the inlet pipe size. Forpipes with a nominal diameter of 14 inches or more, this will be thesame as the outside diameter of the pipe.

Schedule If a pipe schedule is selected, you will be able to select a nominal pipediameter from the pipe databases. It will not be necessary to specifythe internal diameter.

InternalDiameter

The pipe diameter used for the pressure drop calculations.

Use PipeClass

Select Yes to restrict the sizes of the inlet piping selected to thosedefined by the Pipe Class tool.

Fittings Groups

LossCoefficient

Enter the A and B parameters for the following fittings K factorequation in which Ft is the friction factor for fully developed turbulentflow:

K = A + BFt

Summary Tab

The result of the calculations is displayed.

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94

Fig 5.36

Source ToolsThe initial sizing of a flare system is time consuming both in terms of timetaken to build the model and the computation time. Using anmethod can speed up the calculation during the initialSpeed is an important issue during sizing calculations especially for a complexmultiple scenario case. Typically, the back pressure should be used forcalculations. Rigorous rating calculation for all scenarios can be done by thePeng Robinsonpressure dependency and provides the

Source ToolsThe initial sizing of a flare system is time consuming both in terms of timetaken to build the model and the computation time. Using an Ideal Gasmethod can speed up the calculation during the initial sizing estimation.Speed is an important issue during sizing calculations especially for a complexmultiple scenario case. Typically, the back pressure should be used forcalculations. Rigorous rating calculation for all scenarios can be done by the

enthalpy method or any other enthalpy methods withpressure dependency and provides the downstream temperature.

5 Nodes

The initial sizing of a flare system is time consuming both in terms of timeIdeal Gas

sizing estimation.Speed is an important issue during sizing calculations especially for a complexmultiple scenario case. Typically, the back pressure should be used forcalculations. Rigorous rating calculation for all scenarios can be done by the

enthalpy method or any other enthalpy methods withtemperature.

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Updating Downstream Temperatures

The downstream temperatures are only used to define the system entrytemperature when ideal gas enthalpies are used. After several cycles of ratingand sizing calculations, the original values for each source may no longer bevalid. These values may be updated to reflect the results of the lastcalculation using an equation of state enthalpy method as follows:

Click Source Tools in Tools on the Home tab; select Refresh SourceTemperatures from the list.

Adding Single Source Scenarios

The thorough evaluation of a flare network will require the evaluation of manyscenarios. In most systems, there will be the possibility of each relief valvelifting on its own. In the case of a petrochemical complex, this could haveseveral hundred relief valves and the task of setting up the scenarios for eachrelief valve would be time consuming and error prone.

Once all the major scenarios have been defined, select Add Single SourceScenarios from Source Tools. Click Yes to allow Aspen Flare SystemAnalyzer to analyze the existing scenarios to determine the greatest flow ratefor each relief valve and create a scenario using this data.

Flare TipThe Flare Tip is used to model outflows from the system. It can model eitherignited combustible gas flare tips or open vents. Nonphysical equipment suchas a connection to a fixed pressure exit at a plant boundary can also bemodeled.

Connections Tab

The name of the flare tip and connectivity information is specified here.

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96

Fig 5.37

The location can have an alphanumeric name. This feature is useful for largeflowsheets, because you can provide a different “location” name to differentsections to make it more comprehensible.

The following fields are available on this tab:

Field

Name

Location

Upstream node

At

Ignore

Calculations Tab

Calculation methods are specified here.

n can have an alphanumeric name. This feature is useful for largeflowsheets, because you can provide a different “location” name to differentsections to make it more comprehensible.

The following fields are available on this tab:

Description

The alphanumeric description of the Flare Tip (e.g.Tip).

You may want to specify the location of the node in the plant.

Either type in the name of the pipe segment or select from list.

You can specify the end of the pipe segment attached to the flaretip.

Select the Ignore check box to ignore this flare tip in thecalculations. Clear the check box to re-enable it.

Calculations Tab

Calculation methods are specified here.

5 Nodes

n can have an alphanumeric name. This feature is useful for largeflowsheets, because you can provide a different “location” name to different

(e.g. - HP Flare

You may want to specify the location of the node in the plant.

Either type in the name of the pipe segment or select from list.

e pipe segment attached to the flare

box to ignore this flare tip in the

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5 Nodes

Fig 5.38

The following fields are a

Field

Diameter

Methods Group

Use Curves

Fitting LossCoefficient

Fittings LossCoefficient Basis

IsothermalPressure Drop

The following fields are available on this tab:

Description

You can specify a diameter for the tip. If this value is notspecified then the diameter of the connected pipe is used.

Select this check box if you are supplying pressure drop ccalculate the pressure drop of the flare tip. Data for these curvesis entered on the Curves tab.

The fitting loss coefficient will be used to calculate the pressuredrop through the flare tip.

Select whether the supplied Fittings Loss Coefficientcalculate the total pressure loss including velocity pressure lossor static pressure loss only.

If this option is set to Yes, the inlet temperatures used for thesize change calculations in the flare tip will not update duringiterative calculations for pressure loss i.e. a PT flash will be usedto update the inlet properties. If the option is set torigorous PH flash will be used to update the inlet prope

The flare tip will do a one size calculation for the change indiameter between inlet pipe and the flare tip.

Setting this option to Yes can speed up calculations in somecases at cost of a minor loss of accuracy.

97

You can specify a diameter for the tip. If this value is notspecified then the diameter of the connected pipe is used.

box if you are supplying pressure drop curves tocalculate the pressure drop of the flare tip. Data for these curves

The fitting loss coefficient will be used to calculate the pressure

Fittings Loss Coefficient willlocity pressure loss

, the inlet temperatures used for theze change calculations in the flare tip will not update during

iterative calculations for pressure loss i.e. a PT flash will be usedto update the inlet properties. If the option is set to No, a morerigorous PH flash will be used to update the inlet properties.

The flare tip will do a one size calculation for the change in

can speed up calculations in some

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98

Curves Tab

User specified pressurused if the Use Curves

Fig 5.39

The following fields are available on this tab:

Field

Ref. Temp.

PressureCorrection

Mol. Wt.Extrapolation

FlowExtrapolation

Curves Tab

User specified pressure drop curves are specified here. These will only beUse Curves field on the Calculation tab is unchecked.

The following fields are available on this tab:

Description

Enter the reference temperature to which the prcurves correspond. All curves must be for the same referencetemperature.

If checked, the static pressure correction takes into accountdensity differences due to both the calculated inlet pressure andcalculated inlet pressure. The temperature correction isautomatically applied, but this box must be checked in order forpressure effects to be modeled. This box should normally bechecked.

If this is selected, extrapolation beyond the range of suppliemolecular weight curves is performed if necessary; otherwise,the bounding molecular weight curve is used.

If this is selected, extrapolation beyond the range of suppliedmass flow rates is performed if necessary; otherwise, thebounding mass flow is used.

5 Nodes

e drop curves are specified here. These will only beab is unchecked.

Enter the reference temperature to which the pressure dropcurves correspond. All curves must be for the same reference

the static pressure correction takes into accountdensity differences due to both the calculated inlet pressure and

sure. The temperature correction isbut this box must be checked in order for

pressure effects to be modeled. This box should normally be

If this is selected, extrapolation beyond the range of suppliedmolecular weight curves is performed if necessary; otherwise,

If this is selected, extrapolation beyond the range of suppliedmass flow rates is performed if necessary; otherwise, the

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Field

Mol. Wt.

Mass Flow/Pres.Drop

Summary Tab

The result of the calculation is displayed.

Fig 5.40

Description

Enter the molecular weight at which the pressure drop curveapplies. Add Mol. Wt. can be used to add additional curves. Thelist can then be used to select which pressure drop curve isdisplayed. Delete Mol. Wt. will delete the selected pressure dropcurve.

These pairs of data define points in the pressure drop curve.Points may be added and removed from the curve by usingPoint and Delete Point. Pressure drops for flows between thosein the table are calculated using linear interpolation.

Summary Tab

The result of the calculation is displayed.

99

Enter the molecular weight at which the pressure drop curvecan be used to add additional curves. The

list can then be used to select which pressure drop curve isthe selected pressure drop

These pairs of data define points in the pressure drop curve.Points may be added and removed from the curve by using Add

. Pressure drops for flows between thosere calculated using linear interpolation.

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6 Calculations

6 Calculations

This section provides information on the following topics:

Starting the Calculations

Efficient Modeling Techniques

Starting the CaThe following words before the object on the status bar show the type ofcalculation being performed

B = Mass and Energy Calculations

P = Pressure Drop Calculations

To start the calculations, selectthe Ribbon.

The status of the rating calculations is shown on the Status Barthe left corner of the Status Bar shows the status of the current case. Thesecond display fieliteration number, then the maximum pressure error for that iteration andfinally the name of the pipe segment responsible for the error. The thirddisplay field shows firstly the number of iteratiand then the error in the objective function being solved by the loop solver.The right corner of the Status Bar shows thethe percentage zoom setting to quickly zoom in or zoom out when viewing tProcess Flowsheet.

Fig 6.1

To abort calculations

Note: Due to speed considerations, it is recommended that sizing calculationsbe performed subject to the constraints:Enthalpy Method, or

6 Calculations

This section provides information on the following topics:

Starting the Calculations

Efficient Modeling Techniques

Starting the CalculationsThe following words before the object on the status bar show the type ofcalculation being performed:

B = Mass and Energy Calculations

P = Pressure Drop Calculations

To start the calculations, select Run from the Run group, on the

The status of the rating calculations is shown on the Status Barthe left corner of the Status Bar shows the status of the current case. Thesecond display field on the Status Bar shows firstly the inner properties loopiteration number, then the maximum pressure error for that iteration andfinally the name of the pipe segment responsible for the error. The thirddisplay field shows firstly the number of iterations taken by the loop solver,and then the error in the objective function being solved by the loop solver.The right corner of the Status Bar shows the Zoom Slider. You can slide tothe percentage zoom setting to quickly zoom in or zoom out when viewing tProcess Flowsheet.

To abort calculations, click Stop, which activates during calculations.

Due to speed considerations, it is recommended that sizing calculationsbe performed subject to the constraints: Compressible Gas VLE

, or no Heat Transfer Calculations.

101

The following words before the object on the status bar show the type of

the Home tab of

The status of the rating calculations is shown on the Status Bar. The icon onthe left corner of the Status Bar shows the status of the current case. The

d on the Status Bar shows firstly the inner properties loopiteration number, then the maximum pressure error for that iteration andfinally the name of the pipe segment responsible for the error. The third

ons taken by the loop solver,and then the error in the objective function being solved by the loop solver.

. You can slide tothe percentage zoom setting to quickly zoom in or zoom out when viewing the

during calculations.

Due to speed considerations, it is recommended that sizing calculationsVLE, Ideal Gas

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102 6 Calculations

Efficient Modeling TechniquesEfficient modeling of a flare network requires some forethought in order tomeet the primary objectives which are in general:

1 Definition of the design constraints for the flare system. These are usuallydefined by company standards or by local health and safety regulations. Ifunavailable, standard texts such as API-RP-521 can be used to selectpreliminary acceptable values.

2 Efficient acquisition of the data for the piping configuration and layout.

3 Definition of the scenarios or contingencies which should be evaluated.Grass roots design will require analysis of a far wider range of scenarios tothose required by the simple expansion of a flare system to incorporate anew relief valve.

4 Rapid construction of the computer model of the flare system.

5 Fast and efficient calculation of the computer model of the flare system.

Objectives 1 to 3 can only be achieved by the use of engineering skill andjudgment. Once complete, the efficient use of Aspen Flare System Analyzercan lead to a satisfactory project conclusion.

Data EntryAspen Flare System Analyzer has a wide range of methods for entering thedata for each object within the model. In general, you should use the methodthat you are most comfortable with, but experience has shown that use of theProcess Flowsheet environment for definition of the piping configuration andlayout can save many man days of labor with large flare networks.

Although there is no set order in which the model must be built, therecommended sequence of data entry for building the model is:

1 Define the project description, user name, etc. by selecting Descriptionfrom the Application Menu which is displayed after clicking the aspenONEButton on the upper left corner of the application window.

2 Set preferences for the default piping materials, type of Tee, compositionbasis, etc. from the Preferences Editor, accessed via the ApplicationMenu. These may be overwritten on an object by object basis at anystage. Ensure that the Edit Objects On Add check box is selected if youwant to edit the object data as each new flowsheet object is created.

3 Define a pipe class if appropriate. This will ensure that you only use pipesizes as allowed by your project. Open the Pipe Class Editor in the Toolsgroup on the Home tab of the Ribbon.

4 With the Calculation Options Editor, define default calculation methodsfor VLE, Pressure Drop, etc. To open this view, click Options in the Rungroup on the Home tab.

5 Define all the source nodes (relief valves and control valves) for the firstscenario. The first scenario should be the one that has the greatest levelof common data amongst the complete set of scenarios. Therecommended method of creation is to drag the nodes from the Paletteto the Process Flowsheet.

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6 Calculations 103

6 Define the design constraints on Mach number, noise, etc. for the firstscenario using the Scenario Manager. To access this dialog box, in theBuild group on the Home tab, click Scenarios.

7 Define the pipe network (common to all scenarios). If the network is to besized, some care must be taken in defining reasonable estimates for thepipe diameters.

8 Add the next scenario by clicking Add on the Scenario Manager. Thedata for the sources should be cloned from the previously defined scenariothat has the most similar data. Edit the design constraints of this scenarioif necessary.

9 Make the new scenario current. Highlight it on the Scenario Managerand click Current.

10 Edit the source data for each source for the new scenario. Double-clicksources on the Process Flowsheet.

11 Repeat steps 8 through 10 for all scenarios.

Calculation SpeedCalculation time will often be only a small percentage of the time taken toconstruct the computer model. However, on low specification personalcomputers, a sizing calculation for a complex multiple scenario model couldtake several hours, if not days, when care is not taken in the selection of thethermodynamic models or in the definition of the component slate.

When considering the desired accuracy for the calculations, due considerationmust be given to the fact that you are modeling a system that will rarelycome close to a steady state condition, with a steady state modeling tool.

Component Slate

As a rule of thumb you can assume that the calculation time is proportional tothe square of the number of components. This is especially true when theVLE is calculated by an equation of state instead of treating the fluids as asimple compressible gas.

Flare systems generally operate at conditions in which heavy componentssuch as hexane or heavier will stay in the liquid phase throughout the system.You should therefore endeavor to characterize the heavy ends of petroleumfluids by as few components as possible. The properties that you use for thecharacterization should be optimized to:

Ensure the component stays in the liquid phase.

Match the liquid phase density.

VLE Method

Source compositions may be modeled either by definition of a molecularweight or by a detailed component by component analysis. When acomposition is defined solely by molecular weight, Aspen Flare SystemAnalyzer analyzes the user defined component slate to select a pair ofcomponents whose molecular weights straddle the defined value. A binarycomposition is then calculated to match this value. This type of fluidcharacterization is only suitable for network analyses in which the fluids are

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104 6 Calculations

assumed to be vapor, since the VLE behavior cannot be reasonably predictedfrom this level of detail. Thus the Compressible Gas VLE method is the onlyone that should ever be used in association with molecular weight modeling.

When modeling using a detailed component by component analysis, if you areconfident that the system will be liquid free, then the Compressible Gas VLEmethod should be used since it does not have the overhead of determiningthe vapor/liquid equilibrium split. The computation time for the fluidproperties then becomes several orders of magnitudes faster that thoseinvolving a liquid phase.

When modeling a system in which two phase effects are important,consideration must be given to the pressures both upstream of the sourcesand within the flare piping. The Vapor Pressure VLE method, which is thefastest of the multiphase methods, is, strictly speaking, only valid forpressures below 10 bar. The reduced temperature of the fluid should also begreater than 0.3. Experience has shown that it also works to an acceptabledegree of accuracy for flare system analysis at pressures well beyond this. Ifspeed is an issue, it is recommended that a scenario with as many activesources as possible be rated both using one of the cubic equations of stateand this method. If acceptable agreement between the results is achieved, itmay be reasonably assumed that the extrapolation is valid.

Sizing CalculationsThe final calculations upon which a flare system is built should of course bemade using the most detailed model consistent with the quality of dataavailable, but for initial sizing calculations, a number of points should beconsidered when selecting appropriate calculation methods.

There is not generally a great deal of difference between the pressuredrops calculated for a two phase system, whether calculated bytreating the system as a compressible gas or as a two phase fluid. Thisoccurs since the fluid condenses the velocities will decrease while thetwo-phase friction factor will increase.

Unless choked flow is allowed in the system, the back pressure oneach source should not vary greatly with line size. The specification ofa reasonable fixed downstream temperature for each source to beused with the ideal gas enthalpy model should therefore givereasonable results.

The recommended procedure for performing sizing calculations is as follows:

1 Build the network using reasonable estimates for the pipe diameters.Estimate the diameters from:

PM

Wd

300

d = Diameter (m)

W = Mass flow (kg/s)

P = Tip pressure (bar abs)

M = Design mach number

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6 Calculations 105

2 Rate the network for all the scenarios with your desired detailed model forthe VLE and enthalpies. This will give reasonable temperaturesdownstream of each source.

3 Copy the calculated temperatures downstream of each source to thesource data by selecting Refresh Source Temperatures from SourceTools in the Tools group on the Home tab of the Ribbon.

4 Size the network for all scenarios using Compress Gas VLE and IdealGas enthalpies.

5 Rate the network for all the scenarios with your desired detailed model forthe VLE and enthalpies. If there are any design violations, make adebottlenecking calculation with these methods.

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7 Databases 107

7 Databases

This section provides information on the following topics:

Overview

Database Features

Setting the Password

Pipe Schedule Database Editor

Fittings Database Editor

Component Database Editor

OverviewThe data for the various installable components of the model are stored inuser-modifiable database files.

The database files are:

PIPE_SCHEDULE.MDB - The pipe schedule database. This containsdata for both carbon steel and stainless steel pipe.

FITTINGS.MDB - The pipe fittings database.

COMPONENTS.MDB - The pure component database.

These files are initially installed to the Database sub-directory in your AspenFlare System Analyzer working directory.

Note: You may add and edit your own data to the databases. However, youcannot edit or delete any of the original data.

The databases may be password protected by a single password common toeach. If the password has been disabled, or an incorrect access password hasbeen entered, the databases may be reviewed in read-only mode. You musthave defined an access password before any database can be edited.

Note: Original data is always read-only.

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108 7 Databases

Database FeaturesThe Navigation Pane and tabbed environment provide a new user friendly wayto navigate and view simultaneously multiple results and input views. Inputand Results open in a tabbed environment like Microsoft Internet Explorer. Allthe windows are dockable allowing you to organize and customize theworkspace.

Grid ControlsThe data view is supported with rich grid controls for all input and resultviews. The grid controls permit you to sort, custom filter on every columnfield. With filtering, you can restrict the data and choose to view only thosethat want to see.

To access the filters in the data grid, click the filter icon in the columnheader to display a list in which you can choose from.

You may use the following pre-defined auto filters:

Blanks

NonBlanks

Above Average

Below Average

Top 10

Top 10 percentile

Bottom 10

Bottom 10 percentile

If you need to add a custom filter, select Custom from the list. The CustomFilter Selection window is displayed.

You need to add and edit the Operator and Operand in the table, thengroup them with logical conjunction and disjunction to setup a custom filter.The following buttons are available:

Button Description

Add Condition Add a condition in the table. You need to choose a proper Operator,and then input a value for the Operand to complete the newcondition.

RemoveCondition (s)

Remove one or more previously added conditions. Press Ctrl to selectmultiple rows in the table.

Group Selected

'And' Group Group the selected conditions and perform the logical AND operationfor the group. Multiple conditions need to be selected before thisbutton is activated.

'Or' Group Group the selected conditions and perform the logical OR operationfor the group. Multiple conditions need to be selected before thisbutton is activated.

Toggle Toggle the selected logical groups between the logical operationsAND and OR.

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7 Databases

Button

Ungroup

A logical formula is displayed under the table toconditions added. Click

Maneuvering Through the TableClick the table to select a record, and then navigate through thethe navigator and scroll bar controls.

Fig 7.1

PrintingClick Print All to print the pipe schedule, fittings or component data,depending on which editor you are currently using. Aspen Flare SystemAnalyzer prints format

Adding/Deleting DataWhen Add is clicked,the last record on the table. You shoulddata.

1. When you add items, they will then become immediately available to thesimulation.

2. Click Delete

Description

Upgroup the selected conditions.

A logical formula is displayed under the table to show the relation for all theconditions added. Click OK to apply the custom filter.

Maneuvering Through the TableClick the table to select a record, and then navigate through thethe navigator and scroll bar controls.

to print the pipe schedule, fittings or component data,depending on which editor you are currently using. Aspen Flare SystemAnalyzer prints formatted output using the default printer settings.

Adding/Deleting Datais clicked, a new record that contains dummy data is inserted as

the last record on the table. You should override this data with your actual

When you add items, they will then become immediately available to the

to delete the current record.

109

show the relation for all the

Click the table to select a record, and then navigate through the table using

to print the pipe schedule, fittings or component data,depending on which editor you are currently using. Aspen Flare System

ted output using the default printer settings.

a new record that contains dummy data is inserted asoverride this data with your actual

When you add items, they will then become immediately available to the

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110

Note: You can only delete your own data.

3. Click OK to confirm

Setting The PasswordTo set or modify the password:

Select Set Passwordclicking the aspenONE button on the upper left corner of the applicationwindow.

The Password Editor

Fig 7.2

If you have already set your password, you first need to enter the existingpassword before supplying the new one.

1. Enter your existing password in the

2. Enter your new password in both thePassword boxes,

Pipe Schedule Database EditorThe Pipe Schedule Database Editordata for all pipes in the database, and to add and edit user

1 To use the Pipe Schedule Database EditorDatabase Editoryou enter the password, tbe displayed.

You can only delete your own data.

confirm the update for database.

Setting The PasswordTo set or modify the password:

Set Password from the Application Menu that can be opened byclicking the aspenONE button on the upper left corner of the application

ord Editor window will now be displayed.

If you have already set your password, you first need to enter the existingpassword before supplying the new one.

Enter your existing password in the Old Password box.

Enter your new password in both the New Password andboxes, and then click OK. Click Cancel to abort the procedure.

Pipe Schedule Database EditorPipe Schedule Database Editor allows you to view the pipe schedule

s in the database, and to add and edit user-defined entries.

Pipe Schedule Database Editor, select Pipe ScheduleDatabase Editor from the Databases tab on the Navigation Paneyou enter the password, the Pipe Schedule Database Editor

7 Databases

that can be opened byclicking the aspenONE button on the upper left corner of the application

If you have already set your password, you first need to enter the existing

and Confirm Newto abort the procedure.

Pipe Schedule Database Editorallows you to view the pipe schedule

defined entries.

Pipe Schedulen the Navigation Pane. After

Pipe Schedule Database Editor view will

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7 Databases

Fig 7.3

2 If you have already set your password, you will need to enter thepassword before accessing the databases.

3 Select the mateither Carbon

The Nominal Diameterand Group for each entry are tabulated.

The database can be modified by either adding or deAdd or Delete, respectively. Clickprinter defined in thePage Setup in the

For information on the Database view feaSchedule, Fittings and Components Databases, see

If you have already set your password, you will need to enter thepassword before accessing the databases.

Select the material you want to view from the Material list. This may beCarbon Steel or Stainless Steel.

Diameter, Schedule, Internal Diameter, Wall Thicknessfor each entry are tabulated.

The database can be modified by either adding or deleting the entries using, respectively. Click Print All to print the database to the

printer defined in the Page Setup dialog box that can is openedin the Print Preview window.

For information on the Database view features that are common to the PipeSchedule, Fittings and Components Databases, see Database Features

111

If you have already set your password, you will need to enter the

list. This may be

Wall Thickness

leting the entries usingto print the database to the

dialog box that can is opened from File |

tures that are common to the PipeDatabase Features.

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112

Fittings Database EditorThe Fittings Database Editorfittings types in the database, and to add and edit user

To display the Fittings Database Editorfrom the Databasepassword, the Fittings D

Fig 7.4

The description of each fitting, as well as the A and B term in the pipe fittingequation is tabulated. The Reference defines the literature source for thedata.

The pipe fitting equation is:

tBFAK

For information on the Database view features that are common to the PipeSchedule, Fittings and Components Databases, see

Component Database EditorThe Component Datfor all the pure components in the database, and to add and edit userentries.

Fittings Database EditorFittings Database Editor allows you to view the pipe fitt

fittings types in the database, and to add and edit user-defined entries.

Fittings Database Editor, select Fittings Database EditorDatabases tab on the Navigation Pane. After you enter the

Fittings Database Editor will be displayed.

The description of each fitting, as well as the A and B term in the pipe fittingequation is tabulated. The Reference defines the literature source for the

The pipe fitting equation is:

For information on the Database view features that are common to the PipeSchedule, Fittings and Components Databases, see Database Features

Component Database EditorComponent Database Editor allows you to view the component data

for all the pure components in the database, and to add and edit user

7 Databases

allows you to view the pipe fittings data for alldefined entries.

Database Editor. After you enter the

The description of each fitting, as well as the A and B term in the pipe fittingequation is tabulated. The Reference defines the literature source for the

For information on the Database view features that are common to the PipeDatabase Features.

Component Database Editorallows you to view the component data

for all the pure components in the database, and to add and edit user-defined

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7 Databases

To display the Component Database EditorDatabase Editorenter the password, the

Fig 7.5

The data for each component in the database is tabulated.

For information on the Database view features that are common to the PipeSchedule, Fittings and Componen

Importing Component DataAdditional components may be added to the database via an ASCII file whoseformat is given in

Component Database Editor, select ComponentDatabase Editor from the Database tab on the Navigation Paenter the password, the Component Database Editor will be displayed.

The data for each component in the database is tabulated.

For information on the Database view features that are common to the PipeSchedule, Fittings and Components Databases, see Database Features

Importing Component DataAdditional components may be added to the database via an ASCII file whoseformat is given in Appendix A – File Format.

113

Componentstab on the Navigation Pane. After you

will be displayed.

For information on the Database view features that are common to the PipeDatabase Features.

Additional components may be added to the database via an ASCII file whose

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8 Automation

This section provides information on the following topics:

Overview

Objects

Aspen Flare System Analyzer Object Reference

Example

Updating Automation Files From Previous Versions

OverviewAutomation, defined in its simplest terms, is the ability to drive oneapplication from another. For example, the developers of Product A havedecided in their design phase that it would make their product more usable ifthey exposed Product A’s objects, thereby making it accessible to automation.Since Products B, C and D all have the ability to connect to the applicationthat have exposed objects, each can programmatically interact with productA.

The exposure of its objects makes Aspen Flare System Analyzer a verypowerful and useful tool in the design of hybrid solutions. Since access to anapplication through Automation is language-independent, anyone who canwrite code in Visual Basic, C++ or Java, to name three languages, can writeapplications that will interact with Aspen Flare System Analyzer. There are anumber of applications that can be used to access Aspen Flare SystemAnalyzer through Automation, including Microsoft Visual Basic, Microsoft Exceland Visio. With so many combinations of applications that can transferinformation, the possibilities are numerous and the potential for innovativesolutions is endless.

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ObjectsThe key to understanding Automation lies in the concept of objects. An objectis a container that holds a set of related functions and variables. InAutomation terminology, the functions of an object are called Methods andthe variables are called Properties. Consider the example of a simple car. Ifit were an object, a car would have a set of properties such as; make, color,engine, etc. The car object might also have methods such as; drive, refuel,etc. By utilizing the properties and methods of the car object it is possible todefine, manipulate and interact with the object.

Fig 8.1

Each property of the car is a variable that has a value associated with it. Thecolor could be either a string or a hexadecimal number associated with aspecific color. The gas mileage could be a floating-point value. Methods arenothing more than the functions and subroutines associated with the object.

An object is a container that holds all the attributes associated with it. Anobject can contain other objects that are a logical subset of the main object.The car object might contain other objects such as engine or tire. Theseobjects have their own set of independent properties and methods. An enginecan have properties related to the number of valves and the size of thepistons. The tires would have properties such as the tread type or modelnumber.

Object HierarchyThe path that is followed to get to a specific property may involve severalobjects. The path and structure of objects is referred to as the objecthierarchy. In Visual Basic the properties and methods of an object areaccessed by hooking together the appropriate objects through a dot operator(.) function. Each dot operator in the object hierarchy is a function call. Inmany cases it is beneficial to reduce the number of calls by settingintermediate object variables.

For instance, expanding on our previous example involving the car, supposethere exists an object called Car and you wish to set the value of its enginesize. You could approach the problem in one of two ways.

Direct specification of object property

Car.Engine.Size = 3

Indirect specification of object property

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Dim Eng1 as Object

Set Eng1 - Car.Engine.Size

Eng1 = 3

If the Engine size is a property that you wish to access quite often in yourcode, using the indirect method of specification might be easier as it reducesthe amount of code thereby reducing the possibility of error.

The Aspen Flare System Analyzer TypeLibraryIn order to do anything with objects it is first necessary to know what objectsare available. When an application is exposed to Automation, a separate file isusually created that lists all the objects and their respective properties andmethods. This file is called the type library and nearly all programs thatsupport Automation have one of these files available. With the help of anObject Browser, such as the one built into Microsoft Excel, you now have away to view all the objects, properties, and methods in the application byexamining the type library. For Aspen Flare System Analyzer, the type libraryis contained within the file AspenTech.FlareSystemAnalyzer.Interfaces.dll.

The Aspen Flare System Analyzer type library reveals numerous objects thatcontain many combine properties and methods. The type library shows theassociated properties and methods for every object, and returns type forevery property. The type library shows what types of arguments are requiredand what type of value might be returned for every method.

Accessing a specific property or method is accomplished in a hierarchicalfashion by following a chain of exposed objects. The first object in the chain isan object from which all other objects can be accessed. This object willtypically be the main application. In Aspen Flare System Analyzer, thestarting object is the Application object. All other objects are accessible fromthis starting object.

Object BrowserThe type library itself does not exist in a form that is immediately viewable toyou. In order to view the type library, you require the use of an applicationcommonly referred to as an Object Browser. The Object Browser willinterpret the type library and display the relevant information. Microsoft Exceland Visual Basic both include a built in Object Browser.

Accessing the Object Browser in Excel for V7.3Onwards1 Press <Left Alt><F11> or select Visual Basic Editor from Macro group

in the Tools menu (For Excel 2007 or later, please select Visual Basic inthe Code group on the Developer tab).

2 Within the Visual Basic Editor, choose References from the Tools menu.

3 Select the box next to AspenTech.FlareSystemAnalyzer.Interfaces. Ifthis is not displayed, use Browse to locateAspenTech.FlareSystemAnalyzer.Interfaces.dll.

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4 Click OK.

5 Choose Object Browser

6 Click the arrow in the box at the upper left of the window, and then sAspenTech.FlareSystemAnalyzer

Example: Navigating through the type library

This example shows how to navigate through tdetermine the object hierarchy necessary to access a particular property. Thedesired property is the mass flow of a relief valve called “PSV 1” in thecurrently active scenario.

The first step is to start with the starting objeFlare System Analyzer is always the

Fig 8.2

Selecting the Applicationproperties and methods. Examination of the list of properties does not reveala relief valve object so access to a particular relief valve must be throughanother object. The properties that are links to other objects can bedetermined by looking at the type shown when a property is selected. If thetype is not Stringmost likely an object. The object type shown will be found somewhere in theobject list and the next step is to determine the object hierarchy.

With prior experience in Aspen Flare System Analyzer, theobject is a logical choice.

Object Browser from the View menu or press <F2>.

arrow in the box at the upper left of the window, and then sFlareSystemAnalyzer.Interfaces.dll from the list.

Example: Navigating through the type library

This example shows how to navigate through the type library in order todetermine the object hierarchy necessary to access a particular property. Thedesired property is the mass flow of a relief valve called “PSV 1” in thecurrently active scenario.

The first step is to start with the starting object that in the case of AspenFlare System Analyzer is always the Application object.

Application object in the browser reveals all of its relatedproperties and methods. Examination of the list of properties does not reveal

valve object so access to a particular relief valve must be throughanother object. The properties that are links to other objects can bedetermined by looking at the type shown when a property is selected. If the

String, Boolean, Variant, Double, Integer or Longmost likely an object. The object type shown will be found somewhere in theobject list and the next step is to determine the object hierarchy.

With prior experience in Aspen Flare System Analyzer, the ReliefValvesa logical choice.

8 Automation

<F2>.

arrow in the box at the upper left of the window, and then selectfrom the list.

Example: Navigating through the type library

he type library in order todetermine the object hierarchy necessary to access a particular property. Thedesired property is the mass flow of a relief valve called “PSV 1” in the

ct that in the case of Aspen

object in the browser reveals all of its relatedproperties and methods. Examination of the list of properties does not reveal

valve object so access to a particular relief valve must be throughanother object. The properties that are links to other objects can bedetermined by looking at the type shown when a property is selected. If the

Long then it ismost likely an object. The object type shown will be found somewhere in theobject list and the next step is to determine the object hierarchy.

ReliefValves

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8 Automation

Fig 8.3

The ReliefValvessimple object that is a collection of other objects with some properties andmethods for navigation through the collection.

Fig 8.4

The Item properIReliefValve, The argument named “What” is of type Variant which is thedefault argument type for an argument unless otherwise specified. Allcollection objects within Aspen Flare System Analyzer allow accessindividual member of the collection either by index number (like an array) or

ReliefValves object is shown to be of type IReliefValve. This object is asimple object that is a collection of other objects with some properties andmethods for navigation through the collection.

property is shown to return an indexed object of type, The argument named “What” is of type Variant which is the

default argument type for an argument unless otherwise specified. Allcollection objects within Aspen Flare System Analyzer allow accessindividual member of the collection either by index number (like an array) or

119

. This object is asimple object that is a collection of other objects with some properties and

ty is shown to return an indexed object of type, The argument named “What” is of type Variant which is the

default argument type for an argument unless otherwise specified. Allcollection objects within Aspen Flare System Analyzer allow access to anindividual member of the collection either by index number (like an array) or

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directly by name. Named arguments are case insensitive so “PSV 1” is thesame as “psv 1”. Either approach is equally valid.

Examining the IReliefValvePropertyByName

Fig 8.5

This property is a read/write property that is used to access all data for arelief valve.

The argument is a case insensitive string that describes the variable that wewish to access. In thlist of property names for each type of object is given at the end of thischapter.

The resulting syntax to access the desired property is:

ReliefValves.Item(“PSV1”).PropertyByName(“MassFlow”)

Automation Syntax

Declaring Objects

An object in Visual Basic is another type of variable and should be declared.Objects can be declared using the generic type identifierpreferred method however uses the type library reference to declare theobject variables by an explicit object name.

Early Binding:

Dim | Public | Privatelibrary

Late Binding:

directly by name. Named arguments are case insensitive so “PSV 1” is thesame as “psv 1”. Either approach is equally valid.

IReliefValve object type shows a property calledPropertyByName, which is type Variant.

This property is a read/write property that is used to access all data for a

The argument is a case insensitive string that describes the variable that wewish to access. In this case this string would have the valve “MassFlow”. A fulllist of property names for each type of object is given at the end of this

The resulting syntax to access the desired property is:

ReliefValves.Item(“PSV1”).PropertyByName(“MassFlow”)

omation Syntax

Declaring Objects

An object in Visual Basic is another type of variable and should be declared.Objects can be declared using the generic type identifier objectpreferred method however uses the type library reference to declare the

ect variables by an explicit object name.

| Public | Private Objectvar as ObjectName as specified in the type

8 Automation

directly by name. Named arguments are case insensitive so “PSV 1” is the

property called

This property is a read/write property that is used to access all data for a

The argument is a case insensitive string that describes the variable that weis case this string would have the valve “MassFlow”. A full

list of property names for each type of object is given at the end of this

An object in Visual Basic is another type of variable and should be declared.object. The

preferred method however uses the type library reference to declare the

ObjectName as specified in the type

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Dim | Public | Private objectvar as Object

Once a reference to a type library has been established, the actual name ofthe object as it appears in the type library can be used. This is called earlybinding. It offers some advantages over late binding, including speed andaccess to Microsoft’s IntelliSense functionality when using Visual Basic orVBA.

Example: Object Declaration

Early Binding:

Public fnApp as Object

Public thisPsv as Object

Late Binding:

Public fnApp as AspenTech.FlareSystemAnalyzer.Interfaces.Application

Public thisPsv as AspenTech.FlareSystemAnalyzer.Interfaces.IReliefValve

The Set Keyword

Syntax:

Set objectvar = object.[object...].object | Nothing

Connections or references to object variables are made by using the Setkeyword.

Example: Set

Assuming fnApp is set to the Application Object

Dim thisPsv as AspenTech.FlareSystemAnalyzer.Interfaces.IReliefValve

Set thisPsv - fnApp.ReliefValves.item(1)

CreateObject, GetObject

Syntax for creating an instance of an application:

CreateObject (class)

GetObject ([pathname] [,class])

Where class is the starting object as specified in the type library.

In order to begin communication between the client and server applications,an initial link to the server application must be established. In Aspen FlareSystem Analyzer this is accomplished through the starting objectApplication.

The CreateObject function will start a new instance of the main application.CreateObject is used in Aspen Flare System Analyzer with theAspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.Interfaces.Application class as defined in the type library. This connects to themain application interface of Aspen Flare System Analyzer.

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Example: CreateObject

Dim FnApp As Object

Set FnApp = CreateObject(“AspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.Interfaces.Application”)

The following example uses early binding in the object declaration to createan instance of Aspen Flare System Analyzer and then load a specified model.

Example: CreateObject

Dim FnApp AsAspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.Interfaces.Application

Set FnApp = CreateObject(“AspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.Interfaces.Application”)

FnApp.OpenModel “c:\Aspen Flare System Analyzer<version>\Samples\Ole\Excel\olesample.fnw”

The GetObject function will connect to an instance of the server applicationthat is already running. If an instance of the application is not already runningthen a new instance will be started.

Object Properties, Methods and Hierarchy

Syntax for creating and accessing properties:

Set objectvar = object.[object.object...] .object

Variable = object.[object.object...] .object.property

Syntax for accessing methods:

Function Method

returnvalue = object.method ([argument1, argument2, ...])

Subroutine method

object.method argument1, argument2, ...

The sequence of objects is set through a special dot function. Properties andmethods for an object are also accesses through the dot function. It ispreferable to keep the sequences of objects to a minimum since each dotfunction is a call to a link between the client and the server application.

The object hierarchy is an important and fundamental concept for utilizingautomation. A particular property can only be accessed by following a specificchain of objects. The chain always begins with the Application object andends with the object containing the desired property.

The methods of objects are accessed in the same fashion as properties byutilizing the dot function. A method for a particular object is nothing morethan a function or subroutine whose behavior is related to the object in somefashion.

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Typically the methods of an object will require arguments to be passed whenthe method is called. The type library will provide information about whicharguments are necessary to call a particular method. A function will return avalue.

Note: Subroutines in Visual Basic do not require parentheses around theargument list.

Examples: Accessing Aspen Flare SystemAnalyzer Object PropertiesDim FnApp AsAspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.Interfaces.Application

Dim SepDiam as Double

Set FnApp = CreateObject(“AspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.Interfaces.Application”)

FnApp.OpenModel “c:\Aspen Flare System Analyzer<version>\Samples\Ole\Excel\olesample.fnw”

SepDiam - FnApp.HorizontalSeparators.Item[1].PropertyByName(“Diameter”)

This example starts up Aspen Flare System Analyzer and opens a specificcase. The diameter of a specific horizontal separator is then obtained. Thediameter is obtained through a connection of the Application andHorizontalSeparators objects.

Dim FnApp AsAspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.Interfaces.Application

Dim Seps asAspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.Interfaces.IHorizontalSeparators

Dim Sep asAspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.Interfaces.IHorizontalSeparator

Dim SepDiam as Double

Set FnApp = CreateObject(“AspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.Interfaces.Application”)

FnApp.OpenModel “c:\Aspen Flare System Analyzer<version>\Samples\Ole\Excel\olesample.fnw”

Set Seps = FnApp.HorizontalSeparators

Set Sep = Seps.Item[I]

SepDiam = Sep.PropertyByName (“Diameter”)

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This example also gets the diameter of a specific horizontal separator, butcreates all the intermediate objects so that when the diameter value isactually requested the chain of objects only contains one object.

Collection Objects

Syntax: Properties of a Collection Object:

Item(Index) -- Accesses a particular member of the collection by nameor number

Count -- Returns the number of objects in the collection

Syntax: Enumeration of Objects:Dim Element as ObjectDim iElement as LongDim nElements as LongFor iElement=1 to nElementsSet Element = FnApp.Elements.Item(iElement)

[statements]

Next [element]

A collection object is an object that contains a set of other objects. This issimilar to an array of objects. The difference between an array of objects anda collection object is that a collection object is that a collection object containsa set of properties and methods for manipulating the objects in the collection.The Count property returns the number of items in the collection and theItem property takes an index value or name as the argument and returns areference to the object within the collection.

Examples: Accessing Collection Objects

Dim myPsvs as AspenTech.FlareSystemAnalyzer.Interfaces.IReliefValves

Dim name as String

Dim i As Integer

Set myPsvs = myApp.ReliefValves

For i = 1 To myPsvs.Count

name = myPsvs.Item(i).PropertyByName(“Name”)

MsgBox name

Next i

This example connects to a collection of relief valves by setting the myPsvsobject. A For loop is created that uses the Count and item properties of acollection in order to display a message box that display the name of eachrelief valve in turn. The items in the collection are indexed beginning at 1. Theapplication object is assumed to have been already set to myApp.

Variants

Syntax: Using variant values:

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Dim myvariant as Variant

myvariant = [object.property]

To determine the upper and lower bound of the variant:

UBound(arrayname[,dimension])

LBound(arrayname[,dimension])

A property can return a variety of variable type. Values such asTemperature or Pressure are returned as Doubles or 32-bit floating pointvalues. The Name property returns a String value. Visual Basic provides anadditional variable called Variant. A Variant is a variable that can take onthe form of any type of variable including Integer, Long, Double, String,Array, and Objects.

If the property of an object returns an array whose size can vary dependingupon the case, then a Variant is used to access that value. For example, theComposition property of a ControlValve returns an array of Doubles sizedto the number of components in the model.

In Visual Basic, if a variable is not explicitly declared then it is implicitly aVariant. Variants have considerably more storage associated with their useso for a large application it is good practice to limit the number of Variantsbeing used. It is also just good programming practice to explicitly declarevariables whenever possible.

Example: Using Variants in Aspen Flare SystemAnalyzer

Dim myPsvs as AspenTech.FlareSystemAnalyzer.Interfaces.IReliefValve

Dim molefracs as Variant

Dim i As Integer

Set myPsv = myApp.ReliefValves.Item(1)

molefracs = myPsv.PropertyByName (“Composition”)

For i = LBound(molefracs) To Ubound (molefracs)

Debug.Print molefracs(i)

Next i

This example shows how to get the mole fractions of a relief valve for thecurrent scenario. The values are sent to the Visual Basic Immediate window.The application object is assumed to have been already set to myApp.

Unknown Values

There are a number of occasions where a variable may be unknown such asall the calculated values prior to the calculation or the flange size of a controlvalve. In all cases this is represented by the valuefntVariableStatus_fntUnknownValue.

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Example: Using Unknown Values in Aspen FlareSystem Analyzer

Dim myValve as AspenTech.FlareSystemAnalyzer.Interfaces.IControlValves

Dim myValves as AspenTech.FlareSystemAnalyzer.Interfaces.IControlValve

Dim flange as Double

Dim name as String

Set myValves = myApp.ControlValves

For i=1 to myValves.Count

flange = myValves.Item(i).PropertyByName (“FlangeDiameter”)

If flange = fntVariableStatus_fntUnknownValue Then

name = myValve.PropertyByName(“Name”)

MsgBox name

EndIf

Next i

This example loops through all the control valves and displays the name ofany whose flange diameter is unknown. The application object is assumed tohave been already set to myApp.

Aspen Flare System AnalyzerObject ReferenceThe following subsections summarize the methods and properties available foreach object available within Aspen Flare System Analyzer. They are orderedpurely alphabetically.

For each object the attributes comprise the type (or class) of object followedby the access characteristics which may be read-only or read/write. Ingeneral, data has the read/write attribute and calculated values have theread-only attribute.

Each method is shown with the method name including any arguments, adescription of the method and a description of the arguments.

Each property is shown with the property name including any arguments, adescription of the property, the property attributes and a description of thearguments. Optional arguments are shown in square brackets [].

Many objects support a PropertyByName property. In such cases a furthertable gives the valid property names which are case insensitive as well as theproperty attributes and the units of measure where appropriate. The propertynames will generally match the field descriptions on the corresponding viewsbut they never contain any space characters.

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ApplicationDescription : Application object

Methods

Name Description Arguments

OpenModel(fileName AsString)

Open an Aspen FlareSystem Analyzer model

fileName = Model filename

SaveModel(fileName AsString)

Save an Aspen FlareSystem Analyzer model

fileName = Model filename

DoImport(imType AsimportType, source AsString, Definition AsString, Flag As Reserved)As Integer

Import an Aspen FlareSystem Analyzer Model

imType = 0,1,2 forxml,xls,mdb files

source = Import filename

Definition = Definition filename

Flag = 0

DoExport(exType AsexportType, source AsString, Definition AsString, Flag As Reserved)As Integer

Export an Aspen FlareSystem Analyzer Model

exType = 0,1,2 for xml, xls,mdb files

source = Export filename

Definition = Definition filename

Flag = 0

LaunchFlarenet([fileNameAs String])

Display the Aspen FlareSystem Analyzerapplication window

fileName = Model filename

Quit() Quit Aspen Flare SystemAnalyzer.

Please call this method beforeyour scripts end.

Note: The LaunchFlarenet method only launches the Aspen Flare SystemAnalyzer Graphical User Interface (GUI) in a separate process which cannotbe controlled directly. The Quit method cannot terminate the GUI opened bythe LaunchFlarenet method.

Properties

Name Description Attributes Arguments

Bleeds Collection of flow bleedobjects

IBleeds, read-only

Components Collection of componentobjects

IComponents,read-only

Connectors Collection of connectorobjects

IConnectors,read-only

ControlValves Collection of control valveobjects

IControlValves,read-only

HorizontalSeparators

Collection of horizontalseparator objects

IHorizontalSeparators,read-only

Nodes Collection of node objects INodes, read-only

OrificePlates Collection of orifice plateobjects

IOrificePlates,read-only

Pipes Collection of pipe objects IPipes, read-only

ReliefValves Collection of relief valveobjects

IReliefValves,read-only

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Name Description Attributes Arguments

Scenarios Collection of scenario objects IScenarios, read-only

Solver Solver object ISolver, read-only

Tees Collection of tee objects ITees, read-only

Tips Collection of flare tip objects ITips, read-only

VerticalSeparators Collection of verticalseparator objects

IVerticalSeparators, read-only

BleedDescription : Flow bleed object

Attributes : IBleed, read-only

Methods

Name Description Arguments

Connect(ConnectionIdx AsfntNodeEnd, Pipe As IPipe,PipeConnectionIdx AsfntPipeEnd)

Connect to a pipe ConnectionIdx = Connectionon bleed

Pipe = Pipe to connect to

PipeConnectionIdx =Connection on pipe

Disconnect(ConnectionIdxAs fntNodeEnd)

Disconnect from apipe

ConnectionIdx = Connectionon bleed

Properties

Name Description Attributes Arguments

PropertyByName(What As String)

Property value for anamed property

Variant, read/write What = Propertyname

PropertyNames Collection of all theproperty names

String, read-only

Named Properties For PropertyByName()

Name Units Attributes

Ignored fntYesNo, read/write

Location String, read/write

Name String, read/write

OfftakeMaximum kg/hr Double, read/write

OfftakeMinimum kg/hr Double, read/write

OfftakeMultiplier Double, read/write

OfftakeOffset kg/hr Double, read/write

PressureDrop bar Double, read/write

BleedsDescription : Collection of flow bleed objects

Attributes : IBleeds, read-only

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Methods

Name Description Arguments

Add ([Name As String],[Xcoordinate As Single =0] [Ycoordinate As Single= 0])

Add a newbleed

Name: If omitted a new name isautomatically generated

Xcoordinate = X coordinate on theProcess Flowsheet (Twips)

Ycoordinate = Y coordinate on theProcess Flowsheet (Twips)

Delete (What) Delete a bleed What = Index as Name (String) orNumber (Integer/Long)

Properties

Name Description Attributes Arguments

Count Number of items in thecollection

Long, read-only

Item(What)

Indexed item in thecollection

IBleed, read-only

What = Index as Name(String) or Number(Integer/Long)

ComponentDescription : Component object

Attributes : IComponent, read-only

Methods

Name Description Arguments

Clear (Optional CnamecompName As String= Nothing)

Clear all component data Cname = ComponentName. If omitted allcomponents will becleared.

EstimateUnknown Estimate all unknown component data

Properties

Name Description Attributes Arguments

IsValid Validate componentdata is complete

Boolean, read-only

PropertyByName(What As String)

Property value for anamed property

Variant, read/write What = Propertyname

PropertyNames Collection of all theproperty names

String, read-only

Named Properties For PropertyByName()

Name Units Attributes

AcentricFactor Double, read/write

AcentricFactorSrk Double, read/write

CharacteristicVolume m3/kgmole Double, read/write

CriticalPressure bar abs Double, read/write

CriticalTemperature K Double, read/write

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Name Units Attributes

CriticalVolume m3/kgmole Double, read/write

EnthalpyCoefficients kJ/kgmole

kJ/kgmole/K

kJ/kgmole/K2

kJ/kgmole/K3

kJ/kgmole/K4

kJ/kgmole/K5

Double(1 To 6), read/write

EntropyCoefficient Double, read/write

Id Integer, read/write

MolecularWeight Double, read/write

Name String, read/write

NormalBoilingPoint K Double, read/write

StandardDensity kg/m3 Double, read/write

Type fntCompType, read/write

WatsonK Double, read/write

ViscosityCoefficient Double(1 To 2), read/write

ComponentsDescription : Collection of component objects

Attributes : IComponents, read-only

Methods

Name Description Arguments

AddLibrary(What AsVariant)

Add a librarycomponent

What = Component identifier aseither name (String) or ID(Integer/Long)

AddHypothetical(WhatAs String)

Add a namedhypothetical component

What = Name for newcomponent

Delete(What) Delete a component What = Index as component aseither Name (String) or Number(Integer/Long)

Properties

Name Description Attributes Arguments

Count Number of items inthe collection

Long, read-only

Item(What) Indexed item in thecollection

IComponent,read-only

What = Index as Name(String) Or Number(Integer/Long)

ConnectorDescription : Connector node object

Attributes : IConnector, read-only

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Methods

Name Description Arguments

Connect(ConnectionIdxAs fntNodeEnd, Pipe AsIPipe, PipeConnectionIdxAs fntPipeEnd)

Connect to a pipe ConnectionIdx = Connection onconnector

Pipe = Pipe to connect to

PipeConnectionIdx = Connectionon pipe

Disconnect(ConnectionIdxAs fntNodeEnd)

Disconnect from apipe

ConnectionIdx = Connection onconnector

Properties

Name Description Attributes Arguments

PropertyByName(What As String)

Property value for anamed property

Variant,read/write

What = Property name

PropertyNames Collection of all theproperty names

String, read-only

Named Properties For PropertyByName()

Name Units Attributes

Angle radians Double, read/write

Ignored fntYesNo, read/write

Length m Double, read/write

Location String, read/write

Name String, read/write

ConnectorsDescription : Collection of connector objects

Attributes : IConnectors, read-only

Methods

Name Description Arguments

Add ([Name As String],[Xcoordinate As Single =0] [Ycoordinate As Single= 0])

Add a newconnector

Name: If omitted a new name isautomatically generated

Xcoordinate = X coordinate on theProcess Flowsheet (Twips)

Ycoordinate = Y coordinate on theProcess Flowsheet (Twips)

Delete (What) Delete a connector What = Index as Name (String) orNumber (Integer/Long)

Properties

Name Description Attributes Arguments

Count Number of items in thecollection

Long, read-only

Item(What) Indexed item in thecollection

IConnector, read-only

What = Index asName (String) OrNumber(Integer/Long)

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ControlValveDescription : Control valve object

Attributes : IControlValve, read-only

Methods

Name Description Arguments

Connect(ConnectionIdxAs fntNodeEnd, Pipe AsIPipe, PipeConnectionIdxAs fntPipeEnd)

Connect to a pipe ConnectionIdx = Connection oncontrol valve

Pipe = Pipe to connect to

PipeConnectionIdx = Connectionon pipe

Disconnect(ConnectionIdxAs fntNodeEnd)

Disconnect from apipe

ConnectionIdx = Connection oncontrol valve

Properties

Name Description Attributes Arguments

PropertyByName(What As String,

[Scenario])

Property value fora named property

Variant,read/write

What = Property name

Scenario = Scenario Indexas Name (String) orNumber (Integer/Long)

PropertyNames Collection of allthe propertynames

String, read-only

Named Properties For PropertyByName()

Name Units Attributes

Composition fractions Double (1 To ?), read/write

CompositionBasis fntCompBasis, read/write

Energy kJ/hr Double, read-only

Enthalpy kJ/kgmole Double, read-only

Entropy kJ/kgmole/K Double, read-only

FlangeDiameter mm Double, read/write

FluidType fntCompType, read/write

Ignored fntYesNo, read/write

Location String, read/write

LockMabp fntYesNo, read/write

Mabp bar abs Double, read-only

MassFlow kg/hr Double, read/write

MolecularWeight Double, read/write

Name String, read/write

OutletMachNumber Double, read-only

OutletSonicVelocity m/s Double, read-only

OutletTemperature C Double, read-only

OutletTemperatureSpecification C Double, read-only

OutletVelocity m/s Double, read-only

ReliefPressure bar abs Double, read-only

StaticOutletPressure bar abs Double, read-only

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Name Units Attributes

StaticInletPipePressureDrop bar Double, read-only

Temperature C Double, read-only

TemperatureSepcification fntTempSpec, read/write

TotalOutletPressure bar abs Double, read-only

TotalInletPipePressureDrop bar Double, read-only

VapourFraction molar fraction Double, read-only

ControlValvesDescription : Collection of control valve objects

Attributes : IControlValves

Methods

Name Description Arguments

Add ([Name As String],[Xcoordinate As Single =0] [Ycoordinate As Single= 0])

Add a newcontrol valve

Name: If omitted a new name isautomatically generated

Xcoordinate = X coordinate on theProcess Flowsheet (Twips)

Ycoordinate = Y coordinate on theProcess Flowsheet (Twips)

Delete(What) Delete a controlvalve

What = Index as Name (String) orNumber (Integer/Long)

Properties

Name Description Attributes Arguments

Count Number of items inthe collection

Long, read-only

Item(What) Indexed item in thecollection

IControlValve,read-only

What = Index as Name(String) or Number(Integer/Long)

HorizontalSeparatorDescription : Horizontal separator object

Attributes : IHorizontalSeparator, read-only

Methods

Name Description Arguments

Connect(ConnectionIdxAs fntNodeEnd, Pipe AsIPipe, PipeConnectionIdxAs fntPipeEnd)

Connect to a pipe ConnectionIdx = Connection onhorizontal separator

Pipe = Pipe to connect to

PipeConnectionIdx = Connection onpipe

Disconnect(ConnectionIdxAs fntNodeEnd)

Disconnect froma pipe

ConnectionIdx = Connection onhorizontal separator

Properties

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Name Description Attributes Arguments

PropertyByName(What As String)

Property value for a namedproperty

Variant,read/write

What = Propertyname

PropertyNames Collection of all the propertynames

String, read-only

Named Properties For PropertyByName()

Name Units Attributes

Diameter mm Double, read/write

Ignored fntYesNo, read/write

LiquidLevel mm Double, read/write

Location String, read/write

Name String, read/write

HorizontalSeparatorsDescription : Collection of horizontal separator objects

Attributes : IHorizontalSeparators, read-only

Method

Name Description Arguments

Add ([Name AsString],[Xcoordinate AsSingle = 0][Ycoordinate AsSingle = 0])

Add a newhorizontalseparator

Name: If omitted a new name isautomatically generated

Xcoordinate = X coordinate on theProcess Flowsheet (Twips)

Ycoordinate = Y coordinate on theProcess Flowsheet (Twips)

Delete(What) Delete a horizontalseparator

What = Index as Name (String) orNumber (Integer/Long)

Properties

Name Description Attributes Arguments

Count Number of itemsin the collection

Long, read-only

Item(What) Indexed item inthe collection

IHorizontalSeparator, read-only

What = Index as Name (String)Or Number (Integer/Long)

NodesDescription : Collection of all node objects

Attributes : INodes, read-only

Properties

Name Description Attributes Arguments

Count Number of items in thecollection

Long, read-only

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OrificePlateDescription : Orifice plate object

Attributes : IOrificePlate, read-only

Method

Name Description Arguments

Connect(ConnectionIdxAs fntNodeEnd, Pipe AsIPipe, PipeConnectionIdxAs fntPipeEnd)

Connect to apipe

ConnectionIdx = Connection onorifice plate

Pipe = Pipe to connect to

PipeConnectionIdx = Connection onpipe

Disconnect(ConnectionIdxAs fntNodeEnd)

Disconnect froma pipe

ConnectionIdx = Connection onorifice plate

Properties

Name Description Attributes Arguments

PropertyByName(What As String)

Property value for anamed property

Variant,read/write

What = Property name

PropertyNames Variant array of all theproperty names

Variant, read-only

Named Properties For PropertyByName()

Name Units Attributes

Diameter mm Double, read/write

DratioIn Double, read/write

DratioOut Double, read/write

Ignored fntYesNo, read/write

Location String, read/write

Name String, read/write

OrificePlatesDescription : Collection of orifice plate objects

Attributes : IOrificePlates, read-only

Methods

Name Description Arguments

Add ([Name As String],[Xcoordinate As Single =0] [Ycoordinate As Single= 0])

Add a neworifice plate

Name: If omitted a new name isautomatically generated

Xcoordinate = X coordinate on theProcess Flowsheet (Twips)

Ycoordinate = Y coordinate on theProcess Flowsheet (Twips)

Delete(What) Delete an orificeplate

What = Index as Name (String) orNumber (Integer/Long)

Properties

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Name Description Attributes Arguments

Count Number of items in thecollection

Long, read-only

Item(What)

Indexed item in thecollection

IOrificePlate, read-only

What = Index asName (String) OrNumber(Integer/Long)

PipeDescription : Pipe object

Attributes : IPipe, read-only

Methods

Name Description Arguments

AddFitting(FittingNameAs String, [Count AsLong = 1])

Add a fitting to thefittings list

FittingName = Name offitting defined in the pipefittings database

Count = Number of fittingsof this type to add

Connect(ConnectionIdxas fntPipeEnd, Node AsObject,NodeConnectionIdx asfntNodeEnd)

Connect to a node ConnectionIdx =Connection on pipe

Node = Node to connect to

NodeConnectionIdx =Connection on node

DeleteAllFittings() Delete all fittingsfrom the fittings list

DeleteFittingByIndex(FittingIndex As Long)

Delete a fitting fromthe fittings list

FittingIndex = Index offitting in the fittings list todelete

DeleteFittingByName(FittingName As String,[Count As Long = 1])

Delete a fitting fromthe fittings list

FittingName = Name offitting defined in the pipefittings database

Count = Number of fittingsof this type to delete

Disconnect(ConnectionIdx As fntPipeEnd)

Disconnect from anode

ConnectionIdx =Connection on pipe

GetFittingCount() AsLong

Get number offittings in the fittinglist

GetFittingName(FittingIndex As Long) AsString

Get name of indexedpipe fitting

FittingIndex = Index offitting in the fittings list toretrieve name for

Properties

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Name Description Attributes Arguments

PropertyByName(What As String,

[Scenario],[Phase],

[PipeEnd])

Property value for anamed property

Variant,read /write

What = Property name

Scenario = Scenario Index asName (String) or Number(Integer/Long)

Phase = Phase Index(fntFluidPhase)

PipeEnd = Pipe end(fntPipeEnd)

PropertyNames Collection of all theproperty names

String, read-only

UseFittings Flag to indicate if afittings list is usedinstead of losscoefficients

Boolean,read/write

Named Properties For PropertyByName()

Name Units Attributes

AccelerationPressureDrop bar Double, read-only

AmbientTemperature C Double, read-only

CanSize fntYesNo, read/write

MoleFractions Double(1 To ?), read-only

Density kg/m3 Double, read-only

Duty kJ/hr Double, read-only

ElevationChange m Double, read/write

ElevationPressureDrop bar Double, read-only

Emissivity Double, read-only

Energy kJ/hr Double, read-only

Enthalpy kJ/kgmole Double, read-only

Entropy kJ/kgmole/K Double, read-only

EquivalentLength m Double, read-only

ExternalDuty W Double, read/write

ExternalHeatTransferCoefficient W/m2/K Double, read-only

ExternalRadiativeHeatTransferCoefficient W/m2/K Double, read-only

ExternalTemperature C Double, read-only

FittingsLossConstant Double, read-only

FittingsLossMultiplier Double, read-only

FittingsPressureDrop bar Double, read-only

FlowRegime fntFlowRegime, read-only

FrictionFactor Double, read-only

FrictionPressureDrop bar Double, read-only

HeatCapacity kJ/kgmole/K Double, read-only

HeatTransfer kJ/hr Double, read-only

Ignored fntYesNo, read/write

IgnoreHeadRecovery fntYesNo, read/write

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Name Units Attributes

InsulationName String, read/write

InsulationThickness mm Double, read/ write

InsulationThermalConductivity W/m/K Double, read/write

InternalDiameter mm Double, read/write

Length m Double, read/write

LengthMultiplier Double, read/write

Location String, read/write

MachNumber Double, read-only

MassFlow kg/hr Double, read/write

Material fntPipeMaterial,read/write

MolecularWeight Double, read-only

MolarFlow kgmole/hr Double, read-only

Name String, read/write

Noise dB Double, read-only

NominalDiameter String, read/write

OutletTemperatureSpecification C Double, read/write

OverallHeatTransferCoefficient W/m2/K Double, read-only

UsePipeClass fntYesNo, read/write

PhaseFraction Double, read-only

PressureDrop bar Double, read-only

RatedMassFlow kg/hr Double, read-only

ReynoldsNumber Double, read-only

RhoV2 kg/m/s2 Double, read-only

Roughness mm Double, read/write

StaticPressure bar abs Double, read-only

Schedule String, read/write

SurfaceTension dynes/cm Double, read-only

TailPipe fntYesNo, read/write

Temperature C Double, read-only

ThermalConductivity W/m/K Double, read-only

TotalPressure bar abs Double, read-only

VapourFraction molar fraction Double, read-only

Velocity m/s Double, read-only

Viscosity cP Double, read-only

WallThermalConductivity W/m/K Double, read/write

WallTemperature C Double, read-only

WallThickness mm Double, read/write

WindSpeed m/s Double, read/write

Zfactor Double, read-only

PipesDescription : Collection of pipes

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Attributes : IPipes

Methods

Name Description Arguments

Add ([Name As String],[Xcoordinate As Single =0] [Ycoordinate As Single= 0])

Add a newpipe

Name: If omitted a new name isautomatically generated

Xcoordinate = X coordinate on theProcess Flowsheet (Twips)

Ycoordinate = Y coordinate on theProcess Flowsheet (Twips)

Delete(What) Delete a pipe What = Index as Name (String) orNumber (Integer/Long)

Properties

Name Description Attributes Arguments

Count Number of items in thecollection

Long, read-only

Item(What)

Indexed item in thecollection

IPipe, read-only What = Index as Name(String)

or Number (Integer/Long)

ReliefValveDescription : Relief valve object

Attributes : IReliefValve, read-only

Methods

Name Description Arguments

Connect(ConnectionIdx AsfntNodeEnd, Pipe As IPipe,pipeConnectionIdx AsfntPipeEnd)

Connect to apipe

ConnectionIdx = Connection on reliefvalve

Pipe = Pipe to connect to

PipeConnectionIdx = Connection onpipe

Disconnect(ConnectionIdxAs fntNodeEnd)

Disconnectfrom a pipe

ConnectionIdx = Connection on reliefvalve

Properties

Name Description Attributes Arguments

PropertyByName(What As String,

[Scenario])

Property value for anamed property

Variant,read/write

What = Property name

Scenario = ScenarioIndex as Name (String)or Number(Integer/Long)

PropertyNames Collection of all theproperty names

String, read-only

Named Properties For PropertyByName()

Name Units Attributes

Composition fractions Double (1 To ?),read/write

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Name Units Attributes

CompositionBasis fntCompBasis,read/write

Contingency fntContingency,read/write

Energy kJ/hr Double, read-only

Enthalpy kJ/kgmole Double, read-only

Entropy kJ/kgmole/K Double, read-only

FlangeDiameter mm Double, read/write

FluidType fntCompType,read/write

HemCd Double, read/write

HemLiqCd Double. Read/write

Ignored fntYesNo, read/write

Kb Double, read/write

Location String, read/write

LockMabp fntYesNo, read/write

LockReliefPressure fntYesNo, read/write

LockRatedMassFlow fntYesNo, read/write

Mabp bar abs Double, read-only

MassFlow kg/hr Double, read/write

Mawp bar abs Double, read/write

MechanicalPressure bar abs Double, read/write

MolecularWeight Double, read/write

Name String, read/write

Orifice String, read/write

OutletMachNumber Double, read-only

OutletSonicVelocity m/s Double, read-only

OutletTemperature C Double, read-only

OutletTemperatureSpecification C Double, read-only

OutletVelocity m/s Double, read-only

RatedMassFlow kg/hr Double, read/write

ReliefPressure bar abs Double, read-only

SizingBackPressure Bar abs Double, read/write

SizingMethod Integer, read/write

StaticOutletPressure bar abs Double, read-only

StaticInletPipePressureDrop bar Double, read-only

Temperature C Double, read-only

TemperatureSpecification fntTempSpec,read/write

TotalOutletPressure bar abs Double, read-only

TotalInletPipePressureDrop bar Double, read-only

ValveArea mm2 Double, read/write

ValveCount Integer, read/write

ValveType fntPsvType, read/write

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Name Units Attributes

VapourFraction molar fraction Double, read-only

ReliefValvesDescription : Collection of relief valve objects

Attributes : IReleifValves

Methods

Name Description Arguments

Add ([Name As String],[Xcoordinate As Single =0] [Ycoordinate As Single= 0])

Add a new reliefvalve

Name: If omitted a new name isautomatically generated

Xcoordinate = X coordinate onthe Process Flowsheet (Twips)

Ycoordinate = Y coordinated onthe Process Flowsheet (Twips)

Delete(What) Delete a relief valve What = Index as Name (String)or Number (Integer/Long)

Properties

Name Description Attributes Arguments

Count Number of items inthe collection

Long, read-only

Item(What) Indexed item in thecollection

IReliefValve,read-only

What = Index as Name(String) or Number(Integer/Long)

ScenarioDescription : Scenario object

Attributes : IScenario, read-only

Properties

Name Description Attributes Arguments

PropertyByName(What As String)

Property value for anamed property

Variant,read/write

What = Property name

PropertyNames Variant array of all theproperty names

String, read-only

Named Properties For PropertyByName()

Name Units Attributes

AtmosphericPressure bar abs Double, read/write

Calculate fntYesNo, read/write

HeaderLiquidVelocityLimit m/s Double, read/write

HeaderMachLimit Double, read/write

HeaderNoiseLimit dB Double, read/write

HeaderRhoV2Limit kg/m/s2 Double, read/write

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Name Units Attributes

HeaderVapourVelocityLimit m/s Double, read/write

Name String, read/write

TailpipeLiquidVelocityLimit m/s Double, read/write

TailpipeMachLimit Double, read/write

TailpipeNoiseLimit dB Double, read/write

TailpipeRhoV2Limit kg/m/s2 Double, read/write

TailpipeVapourVelocityLimit m/s Double, read/write

ScenariosDescription : Collection of scenario objects

Attributes : IScenarios, read-only

Methods

Name Description Arguments

Add([Name AsString],

[CloneIdx AsLong = 1])

Add a new scenario Name = New scenario name

CloneIdx = Index of scenario to copy datafrom for initialization

Delete(What) Delete a scenario What = Index as Name (String) or Number(Integer/Long)

Properties

Name Description Attributes Arguments

Active Set active scenario What = Index as Name(String) or Number(Integer/Long)

ActiveScenario Get active scenario IScenario, read-only

Count Number of items in thecollection

Long, read-only

Item(What) Indexed item in thecollection

IScenario, read-only

What = Index as Name(String) or Number(Integer/Long)

SolverDescription : Solver object

Attributes : ISolver, read-only

Methods

Name Description Arguments

Halt Stop calculations

Start Start calculations

Properties

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Name Description Attributes Arguments

IsActive Get calculation status Boolean, read-only

PropertyByName(What As String)

Property value for anamed property

Variant,read/write

What = Propertyname

PropertyNames Collection of all theproperty names

String, read-only

Named Properties For PropertyByName()

Name Units Attributes

AmbientTemperature C Double, read/write

AtmosphericPressure bar abs Double, read/write

CalculationMode fntCalcMode, read/write

CheckChokedFlow fntYesNo, read/write

Elements Integer, read/write

EnableHeatTransfer fntYesNo, read/write

EnthalpyMethod fntEnthMethod,read/write

InitialPressure bar abs Double, read/write

KineticEnergyBasis fntKeBasis, read/write

LengthMultiplier Double, read/write

LoopIteration Integer, read-only

LoopIterationLimit Integer, read/write

LoopTolerance % Double, read/write

PressureDropMethod fntPresDropMethod(0 to2), read/write

PropertyIteration Integer, read-only

PropertyIterationLimit Integer, read/write

PropertyTolerance % Double, read/write

ScenarioMode fntScenarioMode,read/write

UnitOperationTolerance % Double, read/write

UseKineticEnergy fntYesNo, read/write

UseRatedFlow fntYesNo, read/write

VleMethod fntVleMethod,read/write

WindSpeed Double, read/write

TeeDescription : Tee object

Attributes : ITee, read-only

Methods

Name Description Arguments

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Name Description Arguments

Connect(ConnectionIdx AsfntNodeEnd, Pipe As IPipe,PipeConnectionIdx AsfntPipeEnd)

Connect to a pipe ConnectionIdx =Connection to tee

Pipe = Pipe to connect to

PipeConnectionIdx =Connection on pipe

Disconnect(ConnectionIdxAs fntNodeEnd)

Disconnect from a pipe ConnectionIdx =Connection on tee

Properties

Name Description Attributes Arguments

PropertyByName(What As String)

Property value for anamed property

Variant,read/write

What = Property name

PropertyNames Collection of all theproperty names

String, read-only

Named Properties For PropertyByName()

Name Units Attributes

Angle fntTeeAngle, read/write

Body fntTeeEnd, read/write

Ignored fntYesNo, read/write

Location String, read/write

Name String, read/write

TeesDescription : Collection of tee objects

Attributes : ITees, read-only

Method

Name Description Arguments

Add ([Name As String],[Xcoordinate As Single =0] [Ycoordinate As Single= 0])

Add a new tee Name: If omitted a new name isautomatically generated

Xcoordinate = X coordinate on theProcess Flowsheet (Twips)

Ycoordinate = Y coordinate on theProcess Flowsheet (Twips)

Delete(What) Delete a tee What = Index as Name (String) orNumber (Integer/Long)

Properties

Name Description Attributes Arguments

Count Number of items inthe collection

Long, read-only

Item(What) Indexed item in thecollection

ITee, read-only What = Index as Name(String) Or Number(Integer/Long)

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TipDescription : Flare tip object

Attributes : ITip, read-only

Methods

Name Description Arguments

AddCurve() Add a pressure dropcurve

AddCurvePoint(Index As Long) Append a point to apressure drop curve

Index = Index of curve

Connect(ConnectionIdx AsfntNodeEnd, Pipe As IPipe,PipeConnectionIdx AsfntPipeEnd)

Connect to a pipe ConnectionIdx =Connection to tee

Pipe = Pipe to connect to

PipeConnectionIdx =Connection on pipe

DeleteCurve(Index As Long) Delete a pressure dropcurve

Index = Index of curve

DeleteCurvePoint(Index As Long,Which As Long)

Index = Index of curve

Which = Index of point

Disconnect(ConnectionIdx AsfntNodeEnd)

Disconnect from a pipe ConnectionIdx =Connection on flare tip

Properties

Name Description Attributes Arguments

CurveMolWt(Index As Long)

Molecular weight ofindexed pressure dropcurve

Double, read/write Index = Curve index

CurvePointMassFlow(Index AsLong, Which AsLong)

Mass flow of point on apressure drop curve(kg/hr)

Double, read/write Index = Index of curve

Which = Index of point

CurvePointPressureDrop(Index AsLong, Which AsLong)

Pressure drop of pointon a pressure dropcurve (bar)

Double, read/write Index = Index of curve

Which = Index of point

PropertyByName(What As String)

Property value for anamed property

Variant,read/write

What = Property name

PropertyNames Collection of all theproperty names

String, read-only

Named Properties For PropertyByName()

Name Units Attributes

Diameter mm Double, read/write

Ignored fntYesNo, read/write

K Double, read/write

Kbasis fntKbasis, read/write

Location String, read/write

Name String, read/write

Reference Temperature Double, read/write

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Name Units Attributes

UseCurves fntYesNo, read/write

TipsDescription : Collection of flare tip objects

Attributes : ITips, read-only

Methods

Name Description Arguments

Add ([Name AsString], [XcoordinateAs Single = 0][Ycoordinate As Single= 0])

Add a newflare tip

Name: If omitted a new name isautomatically generated

Xcoordinate = X coordinate on theProcess Flowsheet (Twips)

Ycoordinate = Y coordinate on theProcess Flowsheet (Twips)

Delete(What) Delete a flaretip

What = Index as Name (String) orNumber (Integer/Long)

Properties

Name Description Attributes Arguments

Count Number of items inthe collection

Long, read-only

Item(What) Indexed item in thecollection

ITip, read-only What = Index as Name(String) Or Number(Integer/Long)

VerticalSeparatorDescription : Vertical separator object

Attributes : IVerticalSeparator, read-only

Methods

Name Description Arguments

Connect(ConnectionIdx AsfntNodeEnd, Pipe As IPipe,PipeConnectionIdx AsfntPipeEnd)

Connect to a pipe ConnectionIdx = Connectionon vertical separator

Pipe = Pipe to connect to

PipeConnectionIdx =Connection on pipe

Disconnect(ConnectionIdxAs fntNodeEnd)

Disconnect from apipe

ConnectionIdx = Connectionon vertical separator

Properties

Name Description Attributes Arguments

PropertyByName(What As String)

Property value for anamed property

Variant,read/write

What = Property name

PropertyNames Collection of all theproperty names

String, read-only

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Named Properties For PropertyByName()

Name Units Attributes

Diameter mm Double, read/write

Ignored Boolean, read/write

Location String, read/write

Name String, read/write

VerticalSeparatorsDescription : Collection of vertical separator objects

Attributes : IVerticalSeparators, read-only

Methods

Name Description Arguments

Add ([Name As String],[Xcoordinate As Single =0] [Ycoordinate As Single= 0])

Add a newverticalseparator

Name: If omitted a new name isautomatically generated

Xcoordinate = X coordinate on theProcess Flowsheet (Twips)

Ycoordinate = Y coordinate on theProcess Flowsheet (Twips)

Delete(What) Delete a verticalseparator

What = Index as Name (String) orNumber (Integer/Long)

Properties

Name Description Attributes Arguments

Count Number of items inthe collection

Long, read-only

Item(What) Indexed item in thecollection

IVerticalSeparator, read-only

What = Index as Name(String) Or Number(Integer/Long)

Example – Automation InVisual BasicThis example shows how that Aspen Flare System Analyzer can be used as anautomation server by a program that analyses an Aspen Flare SystemAnalyzer model to search for the maximum and minimum values of a userdefined named property within all the pipes.

Note: Although Visual Basic 6 is recommended for this example, you maycreate the Automation application in the Visual Basic editor provided inMicrosoft Excel 2007® (or later) and Microsoft Word 2007® (or later).

1 Open a new project in Visual Basic 6®. From the New tab of the NewProject property view; select the Standard EXE icon and click OK. Yourscreen should appear similar as below.

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148

Fig 8.6

2 By default you should have a form associated with thName field of thefrmBounds.

Note: This complete example has also been pre\Samples\Ole\Vb

3 In the Caption field typProperty Boundsform.

4 Before adding objects to the fordifferent objects that will be rProperties wvalue such that the

5 From the Tool Box selectshown below.

By default you should have a form associated with the project. In thefield of the Properties window, give the form the name:

This complete example has also been pre-built and is located in theVb\Bounds directory.

In the Caption field type: Aspen Flare System AnalyzerProperty Bounds. This caption should now appear in the title bar of the

Before adding objects to the form, resize the view to accommodate thedifferent objects that will be required. In the Width filed found in the

window, change the width of the form to 6900value such that the form is sufficiently wide to fully display the caption.

From the Tool Box select Text Box; create a text box on the form as.

8 Automation

e project. In thegive the form the name:

built and is located in the

Model Pipe. This caption should now appear in the title bar of the

, resize the view to accommodate thefiled found in the

00 or to anyis sufficiently wide to fully display the caption.

te a text box on the form as

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8 Automation

Fig 8.7

6 Ensure that the text box is the active control. This can be done in one oftwo ways:

Select the text box on the form so that the object guides appear aroundthe object.

From the boxof the text box you have just created.

7 In the Properties windows, set the name of the text box asebModelNamedefault text that appears inside the edit box by entering a new name inthe Text field.

8 You may add a label to the form. i.e. to identify the object from others, byselecting thetext box you have just created.

9 Ensuring that the label control is active using one of the methodssuggested in step 6, go to thein the Caption

Ensure that the text box is the active control. This can be done in one of

Select the text box on the form so that the object guides appear aroundthe object.

box found at the top of the Properties window,of the text box you have just created.

In the Properties windows, set the name of the text box asebModelName in the Name field. If you wish, you may also change thedefault text that appears inside the edit box by entering a new name in

field.

You may add a label to the form. i.e. to identify the object from others, byselecting the Label tool and drawing the label on the form just above thetext box you have just created.

Ensuring that the label control is active using one of the methodssuggested in step 6, go to the Properties Window and change the text

Caption field to Model Name.

149

Ensure that the text box is the active control. This can be done in one of

Select the text box on the form so that the object guides appear around

select the name

In the Properties windows, set the name of the text box aslso change the

default text that appears inside the edit box by entering a new name in

You may add a label to the form. i.e. to identify the object from others, byabel on the form just above the

Ensuring that the label control is active using one of the methodsand change the text

Page 156: Flarenet modelling

150

Fig 8.8

10 Add the following objects to the form using the previously describedmethods.

Fig 8.9

11 Only two more objects are required on the form. Select theButton control from the tool bar and add two buttons to the form asshown below.

Add the following objects to the form using the previously described

Only two more objects are required on the form. Select thecontrol from the tool bar and add two buttons to the form as

below.

8 Automation

Add the following objects to the form using the previously described

Only two more objects are required on the form. Select the Commandcontrol from the tool bar and add two buttons to the form as

Page 157: Flarenet modelling

8 Automation

Fig 8.10

12 You are now ready to begin defining the events behind the form andobjects. You may enter the code environment using a number of methods

Click View Code

Select Code from the

Double-click the

You are now ready to begin defining the events behind the form andobjects. You may enter the code environment using a number of methods

View Code in the Project window.

from the View menu.

click the frmBounds form.

151

You are now ready to begin defining the events behind the form andobjects. You may enter the code environment using a number of methods:

Page 158: Flarenet modelling

152

Fig 8.11

The Private Sub Form_Load()you enter the code environment by double

13 Begin by declaring the following variables under the Option ExplicitDeclaration.

Fig 8.12

14 Add a reference to the Aspen Flare System Analyzer type library to allowaccess to predefined constantmenu.

Private Sub Form_Load() method definition will only be visible ifyou enter the code environment by double-clicking the form.

Begin by declaring the following variables under the Option Explicit

Add a reference to the Aspen Flare System Analyzer type library to allowaccess to predefined constants by selecting References from the

8 Automation

method definition will only be visible ifclicking the form.

Begin by declaring the following variables under the Option Explicit

Add a reference to the Aspen Flare System Analyzer type library to allowfrom the Project

Page 159: Flarenet modelling

8 Automation

Fig 8.13

15 The first subroutine should already be declared. Thesubroutine is the first subroutine called once the program is run. It isusually used to initializEnter the following code into the

Code

Private SubForm_Load()

ebModelName.Text = ""ebPropertyName.Text =""ebMinValue.Text = ""ebMaxValue.Text = ""

End Sub

16 The next section of code to be added is what will occur when the name ofthe model is changed in the

Code

Private SubebModelName_Validate(CancelAs Boolean)

ModelName = ebModelName.Text

End Sub

The first subroutine should already be declared. The Form_Loadsubroutine is the first subroutine called once the program is run. It isusually used to initialize the variables and objects used by the program.Enter the following code into the Form_Load subroutine.

Explanation

Private SubForm_Load()

Signifies the start of the form load subroutine.You do not have to add as it should already bethere.

elName.Text = ""ebPropertyName.Text =

ebMinValue.Text = ""ebMaxValue.Text = ""

Clears all the text fields.

Signifies the end of the initialization subroutine.This line does not need to be added.

ection of code to be added is what will occur when the name ofthe model is changed in the ebModelName box.

Explanation

Private SubebModelName_Validate(CancelAs Boolean)

Signifies the start of the subroutine.

ModelName = ebModelName.Text Copies the entered name for the modelto the String Variable ModelName

Signifies the end of the subroutine.

153

Form_Loadsubroutine is the first subroutine called once the program is run. It is

e the variables and objects used by the program.

Signifies the start of the form load subroutine.You do not have to add as it should already be

Signifies the end of the initialization subroutine.This line does not need to be added.

ection of code to be added is what will occur when the name of

Signifies the start of the subroutine.

e entered name for the modelto the String Variable ModelName

Signifies the end of the subroutine.

Page 160: Flarenet modelling

154 8 Automation

17 The next section of code to be added is what will occur when the desiredproperty is changed in the ebPropertyName box.

Code Explanation

Private SubebPropertyName_Validate(Cancel As Boolean)

Signifies the start of the subroutine.

PropertyName =ebPropertyName.Text

Copies the entered name for theproperty to the String VariablePropertyName

End Sub Signifies the end of the subroutine.

18 The final two routines define the actions of the two buttons: btnUpdateand btnExit.

Code Explanation

Private Sub btnUpdate_Click() Signifies the start of the subroutine.

Dim OwnedByMe As BooleanDim MaxVal As DoubleDim MinVal As DoubleDim Pipe AsAspenTech.FlareSystemAnalyzer.InterfacesObjectDim iPipe As LongDim npipes As LongDim WorkVal As Double

Declare work variables.

On Error Resume Next Prevents an error from being raisedif, for example, an invalid name forthe property is selected.

If Trim$(ModelName) = "" ThenOwnedByMe = FalseSet FnApp = GetObject(,

"AspenTech.FlareSystemAnalyzer.Interfaces.Application")Else

Set FnApp =CreateObject("AspenTech.FlareSystemAnalyzer.Interfaces.Application")

OwnedByMe = TrueFnApp.OpenModel ModelName

End If

If a model name is defined thenopens the model defined by theString variable ModelName;otherwise, connects to the currentlyrunning instance of Aspen FlareSystem Analyzer.

If Not FnApp Is Nothing Then Ensure successful connection to theApplication object.

MaxVal = -10000000000#MinVal = 10000000000#

Initializes the maximum andminimum values to values outsidethe range of possible values.

npipes = FnApp.Pipes.CountFor iPipe = 1 To npipes

Set pipe =FnApp.Pipes.Item(iPipe)

Loop through all the pipes in themodel.

Page 161: Flarenet modelling

8 Automation 155

Code Explanation

WorkVal =Pipe.PropertyByName(PropertyName)

Get the property named and storesin the String variablePropertyName.

If WorkVal <>fntVariableStatus_fntUnknownValue Then

Check for an unknown value. Do notconsider the value further if it isunknown.

If WorkVal > MaxVal Then MaxVal= WorkVal

Update maximum value.

If WorkVal < MinVal Then MinVal= WorkVal

Update minimum value.

End IfNext iPipe

End of loop and value update.

ebMinValue.Text =Format$(MinVal, "0.000e+00")ebMaxValue.Text =Format$(MaxVal, "0.000e+00")

Update the displayed values in theebMinValue and ebMaxValue Textboxes.

Set FnApp = NothingEnd If

Disconnect the Application object.

End Sub Signifies the end of the subroutine.

Private SubbtnExit_Click()

Signifies the start of the subroutine.

Set FnApp = Nothing Releases the connection to Aspen FlareSystem Analyzer.

Unload MeEnd

Unload the form and end the program.

End Sub Signifies the end of the subroutine.

19 You are now ready to compile and run the program. Before you begin,please ensure that you have a copy of Aspen Flare System Analyzer onthe computer.

20 To compile the program do one of the following:

Click the Start button...

Select Start from the Run menu.

Press <F5> from the keyboard.

Visual Basic will inform you of any errors that occur during compile time.

Updating Automation FilesFrom Previous VersionsAspen Flare System Analyzer now uses a new .Net interface to provide accessto the software via automation. As a result a few changes have to be made inthe way the VB6 application code accesses the available methods andproperties. If you have an existing application, it may fail to run with the new

Page 162: Flarenet modelling

156 8 Automation

interface. Below are some notes on what needs to be updated in yourapplications to ensure it runs successfully in this new version.

1 Currently Application.Visible can only be set to False. The user

cannot make the application visible. The application will be running asusual in the background. The LaunchFlarenet method described in thischapter can be used to launch a separate process showing the graphicaluser interface. This process can only be controlled manually and needs tobe manually terminated as well.

2 In the declarations Integer should be replaced by Long.

3 Objects cannot be enumerated in a collection. Previously you could writethe following code:Dim Pipe As ObjectFor Each Pipe In FnApp.Pipes

WorkVal = Pipe.PropertyByName(PropertyName)…

Next

Now this type of code must be written as follows:Dim iPipe As LongDim npipes As LongFor iPipe = 1 To npipes

Set pipe = FnApp.Pipes.Item(iPipe)WorkVal = pipe.PropertyByName(PropertyName)…

Next iPipe

4 In VB6 enum values are actually constants, thus Enum members can beused directly without the Enum type, e.g. fntUnknownValue. In VB.Net

the Enum type is just a type, not a constant. Also in VB6 it is not possibleto have items of the same name under different Enums, e.g.fntFlowRegime.fntUnknownValue and

fntVariableStatus.fntUnknownValue. Therefore to avoid this issue,

MicroSoft determines that all Enum items should be renamed by havingtheir Enum type as prefix followed by character _. Thus existing codemust be modified to include the new Enum item names. For instance,instead of fntUnknownValue for Variable Status, we now have

fntVariableStatus_fntUnknownValue. Please look in the

AspenTech.FlareSystem.Analyzer Object Browser for the new Enum items’names.

Page 163: Flarenet modelling

9 Theoretical Basis 157

9 Theoretical Basis

Pressure Drop

Pipe Pressure Drop Method

Vapor Phase Pressure Drop Methods

Pressure drop can be calculated either from the theoretically derived equationfor isothermal flow of a compressible fluid in a horizontal pipe2:

02

2In

221

22

2

1

2

a

GLf

RT

PPM

P

P

a

Gf

9.1

weightMolecularM

eTemperaturT

lengthEquivalentL

diameterInternal

factorfrictionFanningf

constantgasUniversalR

pressureDownstreamP

pressureUpstreamP

pipeofareasectionalCrossa

flowMassG

where

f

2

1

:

Page 164: Flarenet modelling

158 9 Theoretical Basis

Or from the theoretically derived equation for adiabatic flow of a compressiblefluid in a horizontal pipe2:

1

2

2

2

1

2

1

1 Inγ

1γ1

1-γ

V

V

V

V

G

a

V

PLAf f

9.2

heatsspecificofRatio

lengthEquivalentL

diameterInternal

factorfrictionFanningf

volumespecificDownstreamV

volumespecificUpstreamV

constantgasUniversalR

pressureUpstreamP

pipeofareasectionalCrossa

flowMassG

where

f

γ

:

2

1

1

The friction factor is calculated using an equation appropriate for the flowregime. These equations correlate the friction factor to the pipe diameter,Reynolds number and roughness of the pipe4:

Turbulent Flow (Re > 4000)

The friction factor may be calculated from either the Round equation:

5.6135.0log61.3

1e

fRe

Re

f

9.3

roughnesspipeAbsolutee

diameterInternal

numberReynoldsRe

factorfrictionFanningf

where

f

:

Or from the Chen21 equation:

8981.01098.1149.7

8257.2

/log

0452.5

7065.3

/log4

1

Re

e

Re

e

f f

Page 165: Flarenet modelling

9 Theoretical Basis 159

9.4

roughnesspipeAbsolutee

diameterInternal

numberReynoldsRe

factorfrictionFanningf

where

f

:

Transition Flow (2100 Re 4000)

Re

e

Re

e

Re

e

f f

0.13

7.3log

02.5

7.3log

02.5

7.3log0.4

1

9.5

roughnesspipeAbsolutee

diameterInternal

numberReynoldsRe

factorfrictionFanningf

where

f

:

Laminar Flow (Re < 2100)

Ref f

16

9.6

numberReynoldsRe

factorfrictionFanningf

where

f

:

The Moody friction factor is related to the Fanning friction factor by:

fm ff 4

9.7

factorfrictionMoodyf

factorfrictionFanningf

where

m

f

:

Page 166: Flarenet modelling

160 9 Theoretical Basis

2-Phase Pressure Drop

Although the Beggs and Brill method was not intended for use with verticalpipes, it is nevertheless commonly used for this purpose, and is thereforeincluded as an option for vertical pressure drop methods.

Beggs and Brill

The Beggs and Brill9 method is based on work done with an air-water mixtureat many different conditions, and is applicable for inclined flow. In the Beggsand Brill correlation, the flow regime is determined using the Froude numberand inlet liquid content. The flow map used is based on horizontal flow andhas four regimes: segregated, intermittent, distributed and transition. Oncethe flow regime has been determined, the liquid hold-up for a horizontal pipeis calculated, using the correlation applicable to that regime. A factor isapplied to this hold-up to account for pipe inclination. From the hold-up, atwo-phase friction factor is calculated and the pressure gradient determined.

Fig 9.1

The boundaries between regions are defined in terms of two constants andthe Froude number10:

321 0207.0481.0757.362.4exp xxxL

9.8

5322 000625.00179.0609.1602.4061.1exp xxxxL

Page 167: Flarenet modelling

9 Theoretical Basis 161

9.9

flowratevolumetricsituInq

qqqcontentliquidInput

Inx

where

gasliquidliquid

λ

:

According to Beggs and Brill:

1 If the Froude number is less than L1, the flow pattern is segregated.

2 If the Froude number is greater than both L1 and L2, the flow pattern isdistributed.

3 If the Froude number is greater than L1 and smaller than L2 the flowpattern is intermittent.

Dukler Method

The Dukler10 method breaks the pressure drop into three components -Friction, Elevation and Acceleration. The total pressure drop is the sum of thepressure drop due to these components:

AEFTotal PPPP

9.10

onacceleratitoduepressureinChangeP

elevationtoduepressureinChangeP

frictiontoduepressureinChangeP

pressureinchangeTotalP

where

A

E

F

Total

:

The pressure drop due to friction is:

Dg

VLfP

c

mmTPF

144

ρ22

9.11

)(

)/2.32(g

)/(ρ

)/(

)(

)(

:

2

3

ftpipeofdiameterInsideD

slbfftlbmconstantnalGravitatio

ftlbmixturephasetwoofDensity

sftvelocity

equalassumingpipelineinmixturephasetwotheofVelocityV

ftpipelinetheoflengthEquivalentL

yempiricalldeterminedfactorfrictionphaseTwof

where

c

m

m

TP

Page 168: Flarenet modelling

162 9 Theoretical Basis

The pressure drop due to elevation is as follows:

144

ρ

HEP

Lh

E

9.12

changeselevationofSumH

densityLiquid

yempiricalldeterminedfactorheadLiquidE

where

L

h

ρ

)(

:

The pressure drop due to acceleration is usually very small in oil/gasdistribution systems, but becomes significant in flare systems:

θcos

ρ

1

ρρ

1

ρ

144

1 2222

2

USL

LPLL

L

GPLg

DSL

LPLL

L

GPLg

c

AR

Q

R

Q

R

Q

R

Q

AgP

9.13

bendpipetheofAngle

capacitypipelineofpercentageaaspipelineinholdupLiquidR

hrftpressureandetemperaturpipelineatflowingliquidofVolumeQ

hrftpressureandetemperaturpipelineatflowinggasofVolumeQ

densityGas

areasectionalCrossA

where

L

LPL

GPL

g

θ

)/(

)/(

ρ

:

3

3

Orkiszewski Method

The Orkiszewski11,12 method assumes there are four different flow regimesexisting in vertical two-phase flow - bubble, slug, annular-slug transition andannular-mist.

The bubble flow regime consists mainly of liquid with a small amount of afree-gas phase. The gas phase consists of small, randomly distributed gasbubbles with varying diameters. The gas phase has little effect on thepressure gradient (with the exception of its density).

In the slug flow regime, the gas phase is most pronounced. The gas bubblescoalesce and form stable bubbles of approximately the same size and shape.The gas bubbles are separated by slugs of a continuous liquid phase. There isa film of liquid around the gas bubbles. The gas bubbles move faster than theliquid phase. At high flow velocities, the liquid can become entrained in thegas bubbles. The gas and liquid phases may have significant effects on thepressure gradient.

Transition flow is the regime where the change from a continuous liquid phaseto a continuous gas phase occurs. In this regime, the gas phase becomes

Page 169: Flarenet modelling

9 Theoretical Basis 163

more dominant, with a significant amount of liquid becoming entrained in thegas phase. The liquid slug between the gas bubbles virtually disappears in thetransition regime.

In the annular-mist regime, the gas phase is continuous and is the controllingphase. The bulk of the liquid is entrained and carried in the gas phase.

Orkiszewski defined bubble flow, slug flow, mist flow and gas velocitynumbers which are used to determine the appropriate flow regime.

If the ratio of superficial gas velocity to the non-slip velocity is less than thebubble flow number, then bubble flow exists, for which the pressure drop is:

Dg

R

V

fPc

L

sL

Ltp2

ρ

2

9.14

)(

)/2.32(

)/(

)/(ρ

)/(

:

2

3

2

ftdiameterHydraulicD

slbfftlbmconstantnalGravitatiog

velocityslipnonondependentfactoressDimensionlR

sftvelocityliquidlSuperficiaV

ftlbdensityLiquid

factorfrictionphaseTwof

lengthoffootperftlbdropPressureP

where

c

L

sL

L

tp

If the ratio of superficial gas velocity to the non-slip velocity is greater thanthe bubble flow number, and the gas velocity number is smaller than the slugflow number, then slug flow exists. The pressure drop in this case is:

rns

rsL

c

nsLtp

VV

VV

Dg

VfP

2

ρ 2

9.15

Constant

velocityriseBubbleV

velocityslipNonV

where

r

ns

:

The pressure drop calculation for mist flow is as follows:

Dg

VfP

c

sg

gtp2

ρ

2

Page 170: Flarenet modelling

164 9 Theoretical Basis

9.16

)/(ρ

)/(

:

3ftlbdensityGas

sftvelocitygaslSuperficiaV

where

g

sg

The pressure drop for transition flow is:

ms PxPP 1

9.17

numbersvelocitygasandflowslugflowmistondependentfactorWeightingx

flowmixedfordropPressurePm

flowslugfordropPressurePs

where

,,,

:

The pressure drop calculated by the previous equations, are for a one-footlength of pipe. These are converted to total pressure drop by:

246371144

ρ

p

ftotal

total

PA

GQ

PLP

9.18

)(

)(

)(

)(

)/(

)/(/

)/(ρ

:

2

3

3

ftsegmentlineofLengthL

abovecalculatedasdroppressureUnitP

psiasegmentinpressureAveragep

ftpipeofareasectionalCrossA

sftrateflowGasG

slbgasliquidcombinedofrateMassQ

ftlbregimeflowingtheofDensity

where

p

f

total

Page 171: Flarenet modelling

9 Theoretical Basis 165

Fittings Pressure Change MethodsThe correlations used for the calculation of the pressure change across afitting are expressed using either the change in static pressure or the changein total pressure. Static pressure and total pressure are related by therelationship:

2

ρ 2vPP st

9.19

In this equation and all subsequent equations, the subscript t refers to totalpressure and the subscript s refers to the static pressure.

Enlargers/Contractions

The pressure change across an enlargement or contraction may be calculatedusing either incompressible or compressible methods. For two phase systemsa correction factor that takes into account the effect of slip between thephases may be applied.

Figure A.2 and A.3 define the configurations for enlargements andcontractions. In these figures the subscript 1 always refers to the fitting inletand subscript 2 always refers to the fitting outlet.

Fig 9.2

Fig 9.3

Page 172: Flarenet modelling

166 9 Theoretical Basis

Fitting Friction Loss Coefficient

The friction loss coefficients for Enlargements & Contractions are given by:

Sudden and Gradual Enlargement

For an enlarger, both Crane & HTFS methods use the same the fittings losscoefficients which are defined by Crane26. These methods are based on theratio of smaller diameter to larger diameter (β).

If < 45

221 β1

2

θsin6.2

K

9.20

Otherwise

221 β1K

9.21

2

diameterlarger odiameter tsmaller of ratio theis β where,

d

d

Sudden and Gradual Contraction

For a contraction the fittings loss coefficient in Crane & HTFS methods arecalculated differently for abrupt sudden contractions. Otherwise thecoefficients are same for Crane & HTFS methods. These calculation methodsare as described below:

Crane

The fitting loss coefficient is calculated as per HTFS27. These methods are

based on the ratio of smaller diameter to larger diameter (β).

21σ

ctCKK

9.22

57806.00.39543σ

σ5385.4σ24265.14σ54038.8σ2211.190.5

1.52.52

tK

9.23

2

1

d

d

where:

Page 173: Flarenet modelling

9 Theoretical Basis 167

The contraction coefficient, is defined by

25.079028.4θ'6240.9 θ'1θ'03614.00179.0 leCc

9.24

oθ/180θ'

:

where

HTFS

The fittings loss coefficients are defined by HTFS27. These methods are same

as the previous Crane method (Equations A.22 – A.24) except for suddencontractions where the contraction coefficient is calculated differently.

If θ = 180 (Abrupt contraction)

σ-10.411

1

cC

9.25

Incompressible Single Phase Flow

The total pressure change across the fitting is given by:

2

ρ 211

1

vKPt

9.26

Velocityv

densityMass

tcoefficienlossFittingsK

changepressureTotalp

where

ρ

:

1

Incompressible Two Phase Flow

Sudden and Gradual Enlargement

The static pressure change across the fitting is given by HTFS27

2

2121

σ

11

LO

l

s

mK

P

9.27

g

g

g

l

g

gLO

xx

ε-1

1

ρ

ρ

ε

222

Page 174: Flarenet modelling

168 9 Theoretical Basis

9.28

tcoefficienlossFittingsK

fractionmassPhasex

fractionvoidPhase

densitymassPhase

fluxMassm

where

1

ε

ρ

:

Sudden and Gradual Contraction

The static pressure change across the fitting is given by HTFS27

222

2

σ1LO

l

ts

mKP

9.29

222 1 gLLO x

9.30

2

2 11

XX

CL

9.31

5.0

ρ

ρ1

l

g

g

g

x

xX

9.32

5.05.0

ρ

ρ

ρ

ρ

l

g

g

lC

9.33

tcoefficienlossFittingsK

fractionmassPhasex

fractionvoidPhase

densitymassPhase

fluxMassm

where

1

ε

ρ

:

Page 175: Flarenet modelling

9 Theoretical Basis 169

Compressible Single Phase Flow

Sudden and Gradual Enlargement

The static pressure change across the fitting is given by HTFS27

1

σρ

ρ

σρ 2

1

1

21m

Ps

9.34

densitymassPhase

fluxMassm

where

ρ

:

Sudden and Gradual Contraction

The static pressure change across the fitting is calculated using the two-phasemethod given in Compressible Two Phase Flow below. The single-phaseproperties are used in place of the two-phase properties.

Compressible Two Phase Flow

Sudden and Gradual Enlargement

The static pressure change across the fitting is given by HTFS27

1

221

σσE

Es v

vmP

9.35

bygivenvolumespecificEquivalentv

where

E

:

1

11

11

5.0

2

l

g

R

R

g

glgRggE

v

v

u

u

xxvxuvxv

9.36

5.0

l

HR

v

vu

9.37

lgggH vxvxv 1

Page 176: Flarenet modelling

170 9 Theoretical Basis

9.38

fractionmassPhasex

densitymassPhase

fluxMassm

where

ρ

:

Sudden and Gradual Contraction

The pressure loss comprises two components. These are the contraction ofthe fluid as is passed from the inlet to the vena contracta plus the expansionof the fluid as it passes from the vena contracta to the outlet. In the followingequations the subscript t refers to the condition at the vena contracta.

For the flow from the inlet to the vena conracta, the pressure change ismodeled in accordance with HTFS27 by:

2

2

11

121

ζ

11 σ

11

cE

EtE

E

E

Cv

v

P

vmd

v

v

9.39

1

ζP

P

9.40

For the flow from the vena contracta to the outlet the pressure change ismodeled used the methods for Sudden and Gradual Expansion given above.

Tees

Tees can be modeled either by using a flow independent loss coefficient foreach flow path or by using variable loss coefficients that are a function of thevolumetric flow and area for each flow path as well as the branch angle. Thefollowing numbering scheme is used to reference the flow paths.

Fig 9.4

Constant Loss Coefficients

The following static pressure loss coefficients values are suggested by theAPI23:

Page 177: Flarenet modelling

9 Theoretical Basis 171

θ13K 23K 12K

31K 32K 21K

<90o 0.76 0.50 1.37 0.76 0.50 1.37

90o 1.37 0.38 1.37 1.37 0.38 1.37

The selection of the coefficient value is dependent on the angle and thedirection of flow through the tee.

For flow into the run, the loss coefficient for tee is:

θ13K 12K

90o 0.38 1.37

<>90o 0.50 1.37

For flow into the branch, the loss coefficient for tee is:

θ 21K23K

90o 1.37 1.37

<>90o 1.37 0.76

For flow into the tail, the loss coefficient for tee is:

θ31K 23K

90o 0.38 1.37

<>90o 0.50 0.76

4.32,1: AFigureinshownasassignedareandnumbersReferencewhere

The static pressure change across the fitting is given by:

2

ρ 2vKPs

9.41

Variable Loss Coefficients

The loss coefficients are a function of the branch angle, branch area to totalflow area ratio and branch volumetric flow to total volumetric flow ratio.These coefficients can be determined either from graphical representation byMiller25 or from the Gardel28 equations. Using these methods, static pressurechanges can be calculated from:

Combining Flow

2

ρ

2

ρ

2

ρ

223

3

233

1

211

13v

Pv

Pv

K

Page 178: Flarenet modelling

172 9 Theoretical Basis

9.42

2

ρ

2

ρ

2

ρ

223

3

233

2

222

23 v

Pv

Pv

K

9.43

Dividing Flow

2

ρ

2

ρ

2

ρ

223

1

211

3

233

31 v

Pv

Pv

K

9.44

2

ρ

2

ρ

2

ρ

223

2

222

3

233

32v

Pv

Pv

K

9.45

Miller Method

A typical Miller chart for 23K in combining flow is shown.

Fig 9.5

Gardel Method

Page 179: Flarenet modelling

9 Theoretical Basis 173

These coefficients can also be calculated analytically from the Gardel28

Equations given below:

Combining flow:

rr

rr

qq

qqK

12

cos1

118.01

cos2.1192.0

2

2

2

13

rr

rr

qq

qqK

12

138.01cos

62.11103.022

23

9.46

Dividing Flow

rr

rr

qq

qqK

12

tan1

14.0

9.011.04.0

3.02

tan3.1195.02

2

2

31

rrrr qqqqK 12.035.0103.022

32

9.47

Where,

qr = Ratio of volumetric flow rate in branch to total volumetric flow rate

Φ = Area ratio of pipe connected with the branch to the pipe carrying the total flow

ρ = Ratio of the fillet radius of the branch to the radius of the pipe connected with the branch

θ = Angle between branch and main flow as shown in Fig 9.4

Orifice Plates

Orifice plates can be modeled either as a sudden contraction from the inletpipe size to the orifice diameter followed by a sudden expansion from theorifice diameter to the outlet pipe size or by using the HTFS equation for athin orifice plate.

1

21β5082.12

4 ρ2β1

β

2.825 0.08956 mPs

9.48

See Incompressible Single Phase Flow on Page 263 for a definition of thesymbols.

Page 180: Flarenet modelling

174 9 Theoretical Basis

Vertical Separators

The Pressure change across the separator comprises the followingcomponents:

Expansion of the multiphase inlet from the inlet diameter, d1, to the bodydiameter dbody.

Contraction of vapor phase outlet from the body diameter, dbody, to the outletdiameter, d2

Friction losses are ignored.

Fig 9.6

Horizontal Separators

The Pressure change across the separator comprises the followingcomponents calculated using the methods described in Incompressible SinglePhase Flow on Page 263:

Expansion of the multiphase inlet from the inlet diameter, d1, to the vaporspace characterized by equivalent diameter of the vapor area.

Contraction of vapor phase outlet from the vapor space characterized by theequivalent diameter of the vapor area, to the outlet diameter, d2

Friction losses are ignored.

Fig 9.7

Page 181: Flarenet modelling

9 Theoretical Basis 175

Vapor-Liquid Equilibrium

Compressible GasThe PVT relationship is expressed as:

ZRTPV

9.49

eTemperaturT

constantGasR

factorilityCompressibZ

VolumeV

PressureP

where

:

The compressibility factor Z is a function of reduced temperature andpressure. The overall critical temperature and pressure are determined usingapplicable mixing rules.

Vapor PressureThe following equations are used for estimating the vapor pressure, given thecomponent critical properties3:

1*0** InωInIn rrr ppp

9.50

60* 169347.0In28862.109648.6

92714.5In rr

r

r TTT

p

Page 182: Flarenet modelling

176 9 Theoretical Basis

9.51

61* 43577.0In4721.136875.16

2518.15In rr

r

r TTT

p

9.52

)(

)(

)/(

ω

)(

)(

)/(

:

*

**

RetemperaturCriticalT

ReTemperaturT

TTetemperaturReducedT

factorAcentric

abspsipressureCriticalp

abspsipressureVapourp

pppressurevapourReducedp

where

oc

o

cr

c

cr

This equation is restricted to reduced temperatures greater than 0.30, andshould not be used below the freezing point. Its use was intended forhydrocarbons, but it generally works well with water.

Soave Redlich KwongIt was noted by Wilson (1965, 1966) that the main drawback of the Redlich-Kwong equation of state was its inability of accurately reproducing the vaporpressures of pure component constituents of a given mixture. He proposed amodification to the RK equation of state using the acentricity as a correlatingparameter, but this approach was widely ignored until 1972, when Soave(1972) proposed a modification of the SRK equation of this form:

bVV

TTa

bV

RTP c

ω,,

9.53

The a term was fitted in such a way as to reproduce the vapor pressure ofhydrocarbons using the acentric factor as a correlating parameter. This led tothe following development:

bVV

a

bV

RTP c

α

9.54

RK22

assametheP

TRa a

c

cac

Page 183: Flarenet modelling

9 Theoretical Basis 177

9.55

5.011α rTS

9.56

20.176ω-ω574.1480.0 S

9.57

The reduced form is:

2599.0

3.8473α

2559.0

3

rrr

rr

VVV

TP

9.58

The SRK equation of state can represent with good accuracy the behavior ofhydrocarbon systems for separation operations, and since it is readilyconverted into computer code, its usage has been extensive in the last twentyyears. Other derived thermodynamic properties, like enthalpies and entropies,are reasonably accurate for engineering work, and the SRK equation enjoyswide acceptance in the engineering community today.

Peng RobinsonPeng and Robinson (1976) noted that although the SRK was an improvementover the RK equation for VLE calculations, the densities for the liquid phasewere still in considerable disagreement with experimental values due to auniversal critical compressibility factor of 0.3333, which was still too high.They proposed a modification to the RK equation which reduced the criticalcompressibility to about 0.307, and which would also represent the VLE ofnatural gas systems accurately. This improved equation is represented by:

bVbbVV

a

bV

RTP c

α

9.59

c

cc

P

TRa

22

45724.0

9.60

c

c

P

RTb 07780.0

9.61

They used the same functional dependency for the term as Soave:

Page 184: Flarenet modelling

178 9 Theoretical Basis

5.011α rTS

9.62

20.26992ω-ω5422.137464.0 S

9.63

0642.05068.0

4.8514α

2534.0

2573.32

rrr

rr

VVV

TP

9.64

The accuracy of the SRK and PR equations of state are roughly the same(except for density calculations).

Physical Properties

Vapor DensityVapor density is calculated using the compressibility factor calculated fromthe Berthalot equation5. This equation correlates the compressibility factor tothe pseudo reduced pressure and pseudo reduced temperature.

2

0.60.10703.00.1

rr

r

TT

PZ

9.65

ZRT

PMρ

9.66

Liquid DensitySaturated liquid volumes are obtained using a corresponding states equationdeveloped by R. W. Hankinson and G. H. Thompson14 which explicitly relatesthe liquid volume of a pure component to its reduced temperature and asecond parameter termed the characteristic volume. This method has beenadopted as an API standard. The pure compound parameters needed in thecorresponding states liquid density (COSTALD) calculations are taken fromthe original tables published by Hankinson and Thompson, and the API databook for components contained in Aspen Flare System Analyzer's library. Theparameters for hypothetical components are based on the API gravity and thegeneralized Lu equation. Although the COSTALD method was developed forsaturated liquid densities, it can be applied to sub-cooled liquid densities, i.e.,

Page 185: Flarenet modelling

9 Theoretical Basis 179

at pressures greater than the vapor pressure, using the Chueh and Prausnitzcorrection factor for compressed fluids. The COSTALD model was modified toimprove its accuracy to predict the density for all systems whose pseudo-reduced temperature is below 1.0. Above this temperature, the equation ofstate compressibility factor is used to calculate the liquid density.

Vapor ViscosityVapor viscosity is calculated from the Golubev3 method. These equationscorrelate the vapor viscosity to molecular weight, temperature and thepseudo critical properties.

Tr > 1.0

167.0

)/29.071.0(667.05.0

0.10000

5.3μ

c

Trc

T

TPM r

9.67

Tr ≤ 1.0

167.0

)965.0(667.05.0

0.10000

5.3μ

c

rc

T

TPM

9.68

Liquid ViscosityAspen Flare System Analyzer will automatically select the model best suitedfor predicting the phase viscosities of the system under study. The modelselected will be from one of the three available in Aspen Flare SystemAnalyzer: a modification of the NBS method (Ely and Hanley), Twu's model,and a modification of the Letsou-Stiel correlation. Aspen Flare SystemAnalyzer will select the appropriate model using the following criteria:

Chemical System Liquid Phase Methodology

Lt Hydrocarbons (NBP < 155 F) Mod Ely & Hanley

Hvy Hydrocarbons (NBP > 155 F) Twu

Non-Ideal Chemicals Mod Letsou-Stiel

All the models are based on corresponding states principles and have beenmodified for more reliable application. These models were selected since theywere found from internal validation to yield the most reliable results for thechemical systems shown. Viscosity predictions for light hydrocarbon liquidphases and vapor phases were found to be handled more reliably by an in-house modification of the original Ely and Hanley model, heavier hydrocarbonliquids were more effectively handled by Twu's model, and chemical systemswere more accurately handled by an in-house modification of the originalLetsou-Stiel model.

Page 186: Flarenet modelling

180 9 Theoretical Basis

A complete description of the original corresponding states (NBS) model usedfor viscosity predictions is presented by Ely and Hanley in their NBSpublication16. The original model has been modified to eliminate the iterativeprocedure for calculating the system shape factors. The generalized Leech-Leland shape factor models have been replaced by component specificmodels. Aspen Flare System Analyzer constructs a PVT map for eachcomponent and regresses the shape factor constants such that the PVT mapcan be reproduced using the reference fluid.

Note: The PVT map is constructed using the COSTALD for the liquid region.The shape factor constants for all the library components have already beenregressed and are stored with the pure component properties.

Pseudo component shape factor constants are regressed when the physicalproperties are supplied. Kinematic or dynamic viscosity versus temperaturecurves may be supplied to replace Aspen Flare System Analyzer's internalpure component viscosity correlations. Aspen Flare System Analyzer uses theviscosity curves, whether supplied or internally calculated, with the physicalproperties to generate a PVT map and regress the shape factor constants.Pure component data is not required, but if it is available it will increase theaccuracy of the calculation.

The general model employs methane as a reference fluid and is applicable tothe entire range of non-polar fluid mixtures in the hydrocarbon industry.Accuracy for highly aromatic or naphthenic oil will be increased by supplyingviscosity curves when available, since the pure component propertygenerators were developed for average crude oils. The model also handleswater and acid gases as well as quantum gases.

Although the modified NBS model handles these systems very well, the Twumethod was found to do a better job of predicting the viscosities of heavierhydrocarbon liquids. The Twu model18 is also based on corresponding statesprinciples, but has implemented a viscosity correlation for n-alkanes as itsreference fluid instead of methane. A complete description of this model isgiven in the paper18 titled "Internally Consistent Correlation for PredictingLiquid Viscosities of Petroleum Fractions".

For chemical systems the modified NBS model of Ely and Hanley is used forpredicting vapor phase viscosities, whereas a modified form of the Letsou-Stiel model15 is used for predicting the liquid viscosities. This method is alsobased on corresponding states principles and was found to performsatisfactorily for the components tested.

The parameters supplied for all Aspen Flare System Analyzer pure librarycomponents have been fit to match existing viscosity data over a broadoperating range. Although this will yield good viscosity predictions as anaverage over the entire range, improved accuracy over a more narrowoperating range can be achieved by supplying viscosity curves for any givencomponent. This may be achieved either by modifying an existing librarycomponent through Aspen Flare System Analyzer's component librarian or byentering the desired component as a hypothetical and supplying its viscositycurve.

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9 Theoretical Basis 181

Liquid Phase Mixing Rules for ViscosityThe estimates of the apparent liquid phase viscosity of immiscibleHydrocarbon Liquid - Aqueous mixtures are calculated using the following"mixing rules":

If the volume fraction of the hydrocarbon phase is greater than or equal to0.33, the following equation is used19:

oilvoileff e 16.3μμ

9.69

phasenHydrocarbofractionVolumev

phasenHydrocarboofViscosity

viscosityApparent

where

oil

oil

eff

μ

μ

:

If the volume fraction of the hydrocarbon phase is less than 0.33, thefollowing equation is used20:

OH

OHoil

OHoil

oileff v2

2

2 μμμ

μ4.0μ5.21μ

9.70

phasenHydrocarbofractionVolumev

phaseAqueousofViscosity

phasenHydrocarboofViscosity

viscosityApparent

where

oil

OH

oil

eff

μ

μ

:

The remaining properties of the pseudo phase are calculated as follows:

)( weightmolecularmwxmw iieff

9.71

)(//1ρ densitymixturepx iieff

9.72

)( heatspecificmistureCpxCp iieff

Page 188: Flarenet modelling

182 9 Theoretical Basis

9.73

Thermal ConductivityAs in viscosity predictions, a number of different models and componentspecific correlations are implemented for prediction of liquid and vapor phasethermal conductivities. The text by Reid, Prausnitz and Polings15 was used asa general guideline in determining which model was best suited for each classof components. For hydrocarbon systems the corresponding states methodproposed by Ely and Hanley16 is generally used. The method requiresmolecular weight, acentric factor and ideal heat capacity for each component.These parameters are tabulated for all library components and may either beinput or calculated for hypothetical components. It is recommended that all ofthese parameters be supplied for non-hydrocarbon hypotheticals to ensurereliable thermal conductivity coefficients and enthalpy departures.

The modifications to the method are identical to those for the viscositycalculations. Shape factors calculated in the viscosity routines are useddirectly in the thermal conductivity equations. The accuracy of the methodwill depend on the consistency of the original PVT map.

The Sato-Reidel method15 is used for liquid phase thermal conductivitypredictions of glycols and acids, the Latini et al. Method15 is used for esters,alcohols and light hydrocarbons in the range of C3 - C7, and the Missenardand Reidel method15 is used for the remaining components.

For vapor phase thermal conductivity predictions, the Misic and Thodos, andChung et al. 15 methods are used. The effect of higher pressure on thermalconductivities is taken into account by the Chung et al. method.

As in viscosity, the thermal conductivity for two liquid phases is approximatedby using empirical mixing rules for generating a single pseudo liquid phaseproperty.

Enthalpy

Ideal Gas

The ideal gas enthalpy is calculated from the following equation:

432 TETDTCTBAH iiiiiideal

9.74

termscapacityheatgasIdealEDCBA

eTemperaturT

enthalpyIdealH

where

,,,,

:

Page 189: Flarenet modelling

9 Theoretical Basis 183

Lee-Kesler

The Lee-Kesler enthalpy method corrects the ideal gas enthalpy fortemperature and pressure.

depideal HHH

9.75

s

c

depr

c

dep

r

s

c

dep

c

dep

RT

H

RT

H

RT

H

RT

H

ω

ω

9.76

E

VT

d

VT

T

cc

VT

T

b

T

bb

ZTRT

H

rr

k

rr

r

kk

rr

t

k

r

kk

kr

k

c

dep

352

332

0.15

22

23

2243

2

9.77

2

γ

234 γ

1β0.1βγ2

r

k

V

r

kkk

kr

k

eVT

cE

9.78

enthalpydeparturegasIdealH

termsKeslerLeedcb

enthalpyIdealH

fluidSimples

fluidReferencer

factorAcentric

enthalpySpecificH

etemperaturCriticalT

where

dep

ideal

c

γβ,,,,

ω

:

Equations of State

The Enthalpy and Entropy calculations are performed rigorously using thefollowing exact thermodynamic relations:

dVPT

PT

RTZ

RT

HHV

V

ID

11

Page 190: Flarenet modelling

184 9 Theoretical Basis

9.79

dVVT

P

RP

PZ

R

SSV

Vo

IDo

11InIn

9.80

For the Peng Robinson Equation of State, we have:

bV

bV

dt

daTa

bRTZ

RT

HH ID

12

12In

2

11

5.0

5.0

5.1

9.81

BZ

BZ

adT

Tda

B

A

P

PBZ

R

SSo

IDo

12

12In

2InIn

5.0

5.0

5.1

9.82

ijji

N

i

N

jji kaaxxa

where

1

:

5.0

1 1

9.83

For the SRK Equation of State:

V

b

dt

daTa

bRTZ

RT

HH ID

1In1

1

9.84

Z

B

adT

Tda

B

A

P

PBZ

R

SSo

IDo 1InInIn

9.85

A and B term definitions are provided below:

Term Peng-Robinson Soave-Redlich-Kwong

ib

ci

ci

P

RT077796.0

ci

ci

P

RT08664.0

ia icia α icia α

Page 191: Flarenet modelling

9 Theoretical Basis 185

Term Peng-Robinson Soave-Redlich-Kwong

cia

ci

ci

P

RT2

457235.0

ci

ci

P

RT2

42748.0

iα 5.011 rii Tm 5.011 rii Tm

im 2ω26992.0ω54226.137646.0 ii 2ω176.0ω57.148.0 ii

ijji

N

i

N

jji kaaxxa

where

1

:

5.0

1 1

9.86

N

iiibxb

and

1

9.87

EntropyS

EnthalpyH

constantgasIdealR

stateReference

gasIdealIDo

Page 192: Flarenet modelling

186 9 Theoretical Basis

NoiseThe sound pressure level at a given distance from the pipe is calculated fromthe following equations. In these equations the noise producing mechanism isassumed to be solely due to the pressure drop due to friction.

4

π36.1

2

L

PWm v

9.88

tr

LWSPL m

r

2

13

π4

η10log10

9.89

velocityfluidAveragev

lossontransmissiwallPipet

pressureinChangeP

efficiencyAcoustic

diameterInternal

pipefromDistancer

levelpressureSoundSPL

lengthEquivalentL

where

η

:

Page 193: Flarenet modelling

9 Theoretical Basis 187

Fig 9.8

The transmission loss due to the pipe wall is calculated from:

0.365.0

0.17

mvt

9.90

velocityfluidAveragev

diameterInternal

areaunitpermasswallPipem

where

:

The acoustical efficiency is calculated from the equation below.

5388.9ln*9986.4exp MPr

9.91

where

Pr = Ratio of higher absolute Pr over lower absolute Pr between two ends ofthe pipe (i.e. if upstream pr.> downstream pr., Pr = upstreampr./downstream pr. Else if upstream pr.< downstream pr., Pr = downstreampr./upstream pr.)

M = Mach No.

0 .0 0.2 0 .4 0 .6 0.8 1.0

Mach N um ber

10 - 11

10 - 10

10 - 9

10 - 8

10 - 7

10 - 6

1 0-5

10 - 4

10 - 3

Aco

usti

cal

Eff

icie

nc

y

pt = 1 0.0

p t = 1.0

p t = 0.1

Page 194: Flarenet modelling

188 9 Theoretical Basis

Page 195: Flarenet modelling

A File Format 189

A File Format

Import/Export DetailsThis section provides further details of the import and export capabilities ofAspen Flare System Analyzer.

Important! The definition format for Import/Export has changed since AspenFlare System Analyzer V7.3. As a result, if you are using Aspen Flare SystemAnalyzer V7.3 or later, you cannot import files generated from Aspen FlareSystem Analyzer V7.2 and earlier versions or export on top of a file that hasbeen generated using Aspen Flare System Analyzer V7.2 or earlier versions.

Process Descriptions

Import Wizard

The purpose of this section of the documentation is to describe step by stepthe operation of the import wizard.

End of Step 1

At this stage the import process verifies that the specified import file existsand opens it. The import wizard is then configured for the appropriate filetype.

Any errors are reported.

End of Step 2

At this stage the import process opens the specified import definition file orthe default or new import definition file as specified in Preferences asappropriate. A check is made that the import definition file type matches thefile type specified in step 1. The version of the import definition file is thenchecked; data object and data item elements are added to update to thecurrent Aspen Flare System Analyzer version if required.

The next step is to process the file to build the object selector tree view forStep 3. Any problems in reading the import definition file are reported.

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190 A File Format

Step 3

During this step, the Import Wizard extracts Source tab data and FieldDetails for each data item as different data objects are selected. Whenever anew data object is selected, the data on the Source tab is validated and anyproblems are reported.

End of Step 4

The first action taken is to save the import definition file if required,prompting for the file name to be used. The import process then begins. Indetail, the steps are:

1 Clear current results.

2 Open log file if required.

3 Read components one by one. For each component check to see if italready exists in the current Aspen Flare System Analyzer case. If not,add the component to list. For database components, use informationfrom database; otherwise, use the data values from file.

4 Read binary interaction parameter data.

5 Read data for pipes, connector nodes and source nodes one object type ata time; updating the progress view as appropriate.

6 As each instance of a particular object type is read, check if it alreadyexists. If so, use the data read to update it; otherwise, create a newinstance of the appropriate object type.

7 Make connections between pipes and nodes. Processing allows for onlyone end of the connection to be read.

8 Read scenario data. Existing scenarios will be updated, and new onescreated if required.

9 Read Solver options.

10 Update automatic calculations to reflect new data values.

11 Refresh all views.

12 Close log file, and then close Import Data File. Any background copy ofExcel will be closed at this point.

13 Close the Import Wizard and finish.

General Data Object Import Procedure

For each object type that is read, the detailed import procedure is as follows:

1 Check to see if import of this object type is required. Quit reading thistype of data object if not.

2 Process the data object definition data from the Import Definition File.Search for and open the specified source object. Quit if any errors areencountered.

3 Search the source data object for an instance of the appropriate objecttype using the defined select criteria if required. For Access imports, thiswill be a row in the specified table; for Excel imports, this will be a row orcolumn range in the specified worksheet where cell offset 1,1 is not blank;for XML imports, this will be an item element within the specified groupelement.

4 Repeat steps 2 and 3 to open any sub section data objects.

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A File Format 191

5 Read data items from source one by one.

6 Update counters for number of instances read and search data source fornext object instance. For an Access imports, this will be the next row; forExcel imports, the next row or column range; for XML imports, the nextitem element. Selection criteria will apply if specified. Quit if the nextinstance cannot be found.

7 Repeat steps 5 and 6 until all instances have been read.

Export Process

The purpose of this section of the documentation is to describe step by stepthe operation of the export wizard.

End of Step 1

At this stage the export process checks to see if the target export file exists.If so, it opens the file; otherwise, a new file with the defined name is created.The Export Wizard is then configured for the appropriate file type.

Any errors are reported.

End of Step 2

At this stage, the export process opens the specified export definition file orthe default or new export definition file specified in Preferences asappropriate. A check is made that the export definition file type matches thefile type specified in step 1. The version of the export definition file is thenchecked and data object and data item elements are added to update it to thecurrent Aspen Flare System Analyzer version if required.

The next step is to process the file to build the object selector tree view forStep 3. Any problems in reading the export definition file are reported.

Step 3

During this step, the Export Wizard extracts Target tab data and FieldDetails for each data item as different data objects are selected. Whenever anew data object is selected, the data on the Target tab is validated and anyproblems are reported.

End of Step 4

The first action taken is to save the export definition file if required,prompting for the file name to be used. The export process then begins. Indetail the steps are:

1 Clear existing data from export file if requested.

2 Write components data.

3 Write binary interaction parameter data.

4 Write pipe data.

5 Write connector node and source node data, working through each type ofnode in turn.

6 Write scenario data for scenarios that are selected for calculation.

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192 A File Format

7 Write results data for scenarios that are selected for calculation.

8 Write solver options.

9 Save export file. Any background copy of Excel will be closed at this point.

10 Close the Export Wizard.

General Data Object Export Procedure

For each object type that is written, the detailed export procedure is asfollows:

1 Check that export of this data object type is required. Quit if not.

2 Create target data object using information from export definition file. ForAccess export, this will create a table with the correct fields; for Excelexport, a worksheet with the correct name; for XML export, a group tagwith the correct name. Quit if any errors are encountered.

3 Create target data objects as required for any data subsections.

4 For each instance of the data object to be written, search the output file tosee if this instance already exists. If so, select this to be overwritten;otherwise, create a new instance for the data object in the output file. ForAccess export, this will be a new row in that target table; for Excel export,the next row or column range where cell offset 1,1 is blank; for XMLexport, a new item element. Quit if the new target instance cannot befound.

5 Write the values to the target object instance.

6 Update counters for number of items read and mark target instance ascomplete.

7 Repeat steps 4 to 6 until each instance of this data object has beenwritten.

Definition File FormatsThe import and export definition files are XML formatted data files thatdescribe how the various Aspen Flare System Analyzer data objects and theircorresponding data items should be read from or written to the supportedexternal file formats. This section of the documentation describes the layoutof these files.

Import File Formats

File Header

The top level element of an import definition file must have the tag nameFlarenetImport and contain the following attributes:

Attribute Description

LastModified This is a date string that indicates the date that the file was lastupdated.

FlarenetVersion This indicates the version of Aspen Flare System Analyzer that thefile is applicable to.

FileType This indicates the type of external file import that is described inthis definition file. Valid values are Access, Excel or XML.

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A File Format 193

Data Object Elements

The child elements of the FlarenetImport tag define the various data objectsthat may be imported by Aspen Flare System Analyzer. These parent dataobject elements may contain child data object elements that describe datasubsections which may be imported from a different location to the parentdata object. For example, a pipe data object has a data subsection defined forthe PFD layout information.

A data object element has the following attributes:

Attribute Description

ObjectName This defines the source of the data object in the external file. Its usagedepends on the type of external file as follows:

Access – The entry defines a database table.

Excel – The entry defines a worksheet.

XML – The entry defines the tag name of a group element.

Import This indicates whether this object type is to be imported. Valid valuesare Yes or No.

Contained This indicates whether the data for this object is contained in the sameexternal data source as the parent object. Valid values are Yes or No.This setting is always No for a parent data object.

DataBy This entry appears in Excel import definition files only. It defines howthe data for this object is organized. Valid values are Row, Column orSheet.

StartAt This entry appears in Excel import definition files only. When DataBy isset to Row or Column, it defines the starting row or column for thedata. When DataBy is set to Sheet, it defines the tag by whichworksheets of the requisite layout can be identified.

PerItem This entry appears in Excel import definition files only. It defines thenumber of rows or columns occupied by a single instance of a dataobject, including any spacing, when DataBy is set to Row or Column.

ItemTag This entry appears in XML import definition files only. It defines theelement tag name used to identify each instance of a data object withinthe group tag name defined in the ObjectName attribute.

A list of valid Data Object elements names is given in Data Objects List.

Data Item Elements

Each data object element contains data item elements that define the locationof the individual data item in the external data source. A data item elementcontains the following attributes:

Attribute Description

Import This indicates whether the item is to be imported. Valid values are Yesor No.

Page 200: Flarenet modelling

194 A File Format

Attribute Description

Offset This defines the location of the data value in the external file. Its usagedepends on the type of external file, but data substitution codes can bedefined for the offset in all cases – see Data Substitution Codes.

Access – The entry defines a field within the database table forthe object.

Excel – The entry defines a cell within the worksheet for theobject. The cell is defined either by a single row or column offsetor by a row, column offset.

XML – The entry defines the tag name of an element within theitem tag element for the object.

A list of the data item elements that are recognized for each data object isgiven in Data Items List.

Export File Formats

File Header

The top level element of an export definition file must have the tag nameFlarenetExport and contain the following attributes:

Attribute Description

LastModified This is a date string that indicates the date that the file was lastupdated.

FlarenetVersion This indicates the version of Aspen Flare System Analyzer that thefile is applicable to.

FileType This indicates the type of external file export that is described in thisdefinition file. Valid values are Access, Excel or XML.

Data Object Elements

The child elements of the FlarenetExport tag define the various data objectsthat may be exported by Aspen Flare System Analyzer. These parent dataobject elements may contain child data object elements that describe datasubsections which may be exported to a different location to the parent dataobject.

A data object element has the following attributes:

Attribute Description

ObjectName This defines the name of the data object that will be created and writtento in the external file. Its usage depends on the type of external file asfollows:

Access – The entry defines a database table.

Excel – The entry defines a worksheet.

XML – The entry defines the tag name of a group element.

Export This indicates whether this object type is to be exported. Valid valuesare Yes or No.

Contained This indicates whether the data for this object is to be written to thesame external data source as the parent object. Valid values are Yes orNo. This setting is always No for a parent data object.

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Attribute Description

DataBy This entry appears in Excel export definition files only. It defines howthe data for this object is organized. Valid values are Row, Column orSheet.

StartAt This entry appears in Excel export definition files only. When DataBy isset to Row or Column, it defines the starting row or column for thedata. When DataBy is set to Sheet, it defines the name of theworksheet that will be copied to create a worksheet for each instance ofthe data object. This name must begin with a “%” character.

PerItem This entry appears in Excel export definition files only. It defines thenumber of rows or columns occupied by a single instance of a dataobject, including any spacing, when DataBy is set to Row or Column.

ItemTag This entry appears in XML export definition files only. It defines theelement tag name used to identify each instance of a data object withinthe group tag name defined in the ObjectName attribute.

A list of valid Data Object elements names is given in Data Objects List.

Data Item Elements

Each data object element contains data item elements that define how anindividual data item is to be written to the external data source. A data itemelement contains the following attributes:

Attribute Description

Export This indicates whether the item is to be exported. Valid values are Yesor No.

Offset This defines the location where the data value will be written in theexternal file. Its usage depends on the type of external file, but datasubstitution codes can be defined for the offset in all cases – see DataSubstitution Codes.

Access – The entry defines a field within the database table forthe object.

Excel – The entry defines a cell within the worksheet for theobject. The cell is defined either by a single row or column offsetor by a row, column offset.

XML – The entry defines the tag name of an element within theitem tag element for the object.

Type This appears in Access export definition files only. It defines the datatype of the field to be created for this item. Valid values are Text fortext strings, Long for integer values, Double for floating point values.

Length This appears in Access export definition files only. It defines the length ofthe field to be created. For fields of type Text, it defines the length ofthe text string in characters; for fields of types Long and Double, it isset to 0 and will be ignored though it must be present.

A list of the data item elements that are recognized for each data object isgiven in Data Items List.

Data Substitution Codes

As indicated in the above data substitution codes may be defined in the Offsetattribute for item import and export data items. The details of these codes areas follows:

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Offset Codes

The following codes are recognized and processed in the Offset attribute inboth import and export definition files.

“%ObjectName”

where ObjectName is the name of a data object element, will be replacedby a value that iterates as successive instances of that type of object areread or written for this instance of the parent data object. It is used toprovide a value that iterates through repeated data items, e.g. componentdata or pipe fitting data. ObjectName may refer to any data objectelement that is a parent of the data item. The code is usually used inconjunction with a + symbol to add the iteration value to some constantvalue.

In an Access or XML import or export definition file, the + symbol meansthat the iteration value is concatenated with the constant value. E.g.Frac+%Composition will be expanded to Frac1, Frac2 etc.

In an Excel import or export definition file, *, -, and / symbols as well asthe + symbol are recognized to combine the iteration value with aconstant value to calculate a cell address. E.g. 2,2+%Composition will beexpanded to the cell references 2,3 then 2,4 etc. See the CurveMassFlowdata item in the TipCurveData data object in the definition fileDefExcel.fni for a more complicated example.

“#ObjectName”

where ObjectName is the name of a data object element, will be replacedby the total number of instances of that type of data object that havebeen read. ObjectName may refer to any data object element that is achild of the current data object element. The value returned is usuallycombined with some constant value through a + or other symbols as forthe “%ObjectName” code.

“?Composition”

is a special code that is used exactly as it stands. “?Composition” will bereplaced by each component name or offset in turn as successivecomponent composition data items are read or written. It is generallyused in conjunction with a + symbol to each component name or offset tosome constant value.

In an Access or XML import or export definition file, ?Composition willreturn component names in turn from the master component list. e.g.Frac+?Composition will be evaluated as FracMethane, FracEthane etc.

In an Excel import or export definition, ?Composition will return the indexnumber of a component in the master component list to allow it to beused to calculate a cell offset.

In both cases, the master component list is the union of the componentsin the current Aspen Flare System Analyzer case and the import or exportdefinition files. Essentially this code allows unambiguous specification of acomponent identity when merging of the component lists between a AspenFlare System Analyzer case and an import or export definition file.

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Recognized Objects and Items

Data Objects List

Data object elements for the following data objects and sub-sections arerecognized in import and export definition files.

Element Tag Sub Section DataObject Elements

Description

Components None Component data

BIPs None Binary interaction parameters

Connectors PFDLayout Connector nodes

ControlValves PFDLayout

Composition

SourceData

Control valve source nodes

FlowBleeds PFDLayout Flow bleed nodes

HorizontalSeparators Composition

PFDLayout

Horizontal separator nodes

OrificePlates PFDLayout Orifice plate nodes

Fitting None Fitting data for pipes

Pipes PFDLayout

Fitting

Pipes

ReliefValves PFDLayout

SourceData

Relief valve source nodes

Tees PFDLayout Tee nodes

FlareTips PFDLayout

Curves

Flare tip nodes

Curves Points Tip pressure drop curves

Points None Data points in tip pressure drop curve

VerticalSeparators PFDLayout Vertical separator nodes

Solvers None Solver options

Scenarios SourceData Scenario data

Composition None Component composition data

SourceData Composition Scenario specific source data

PFDLayout None PFD layout information

Results Phase Summary results data for each pipe.Export definition files only.

Phase CompResults Properties for each phase at each end ofeach pipe. Export definition files only.

CompResults None Composition results for each pipe. Exportdefinition files only.

Data Items List

The data items that can be read for each data object are as follows:

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Components

Attribute Description

Hypothetical The hypothetical components

Name The component name

Id The component ID number

Type The component type

Formula The component formula

MolWt The component molecular weight

NBP The component normal boiling point (K)

StdDensity The component standard density (kg/m3)

WatsonK The component Watson K value

Pc The component critical pressure (bar a)

Tc The component critical temperature (K)

Vc The component critical volume (m3/kgmole)

Vchar The component characteristic volume (m3/kgmole)

Omega The component acentric factor

OmegaSRK The component SRK acentric factor

Ha The enthalpy A coefficient (kJ/kgmole)

Hb The enthalpy B coefficient (kJ/kgmole/K)

Hc The enthalpy C coefficient (kJ/kgmole/K2)

Hd The enthalpy C coefficient (kJ/kgmole/K3)

He The enthalpy C coefficient (kJ/kgmole/K4)

Hf The enthalpy C coefficient (kJ/kgmole/K5)

S The entropy coefficient

ViscA The viscosity A parameter

ViscB The viscosity B parameter

HeatOFCombustion The heat of combustion

NBPValue The value of normal boiling point

PcValue The value of critical pressure

TcValue The value of critical temperature

BIPs

Attribute Description

PropPkg The code for the property package:

0 – Vapor pressure

1 – Peng Robinson

2 – Soave Redlich Kwong

3 – Compressible Gas

Comp1 The name of the first component

Comp2 The name of the second component

Kij12 Value of interaction parameter for comp1 / comp2

Kij21 Value of interaction parameter for comp2 / comp1

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Connectors

Attribute Description

FittingLossMethod Code for the fitting loss method: 0 = ignored, 1 =calculated

IsothermalDPOption Code for enabling isothermal pressure dropcalculations: 0 = No, 1 = Yes

TwoPhaseCorrection Code for two phase correction option: 0 = No, 1 = Yes

SwageMethod Code for size change calculation method: 0 =Compressible, 1 = Incompressible, 2 = Transition

CompressibleTransition DP percent of inlet pressure for transition (%)

Length Length of the swage (mm)

Angle The internal angle of the swage (radians)

ChokeMethod Choke flow check

MaxConnectionCount Maximum possible connection count

DescribeCalculations Describe calculations

Name The connector name

Location The location text

Ignore The ignored flag: 0 = not ignored, 1=ignored

UpstreamConnection The name of the upstream pipe

UpstreamConnectionAt Code for the upstream pipe connection point: 0 =upstream end, 1 = downstream end

DownstreamConnnection The name of the downstream pipe

DownstreamConnnectionAt Code for the downstream pipe connection point: 0 =upstream end, 1 = downstream end

ConnectedCount Connection count

ControlValves

Attribute Description

DescribeCalculations Describe calculations

MaxConnectionCount Maximum possible connection count

Ignore Ignore flag

KMultiply Fittings loss Ft factor for inlet pipe

KOffset Fittings loss offset for inlet pipe

FlangeDiameter Internal diameter of flange (mm)

ElevationChange The elevation change of the inlet piping (m)

Length The length of the inlet piping (m)

InternalDiameter The inlet pipe diameter (mm)

Schedule The inlet pipe schedule

NominalDiameter The inlet pipe nominal diameter

Roughness The inlet pipe roughness (mm)

Material The code for the inlet pipe material: 0 = CarbonSteel, 1 = Stainless steel

Thickness Code for the thickness of the pipe wall

UsePipeClass Code for enabling pipe class usage: 0 = No, 1 =Yes

Name The control valve name

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Attribute Description

Location The location text

UpstreamConnnection The name of the upstream pipe

UpstreamConnnectionAt Code for the upstream pipe connection point: 0 =upstream end, 1 = downstream end

ConnectedCount Connection count

FlowBleeds

Attribute Description

OfftakeMultiplier Flow bleed multiplier

OfftakeOffset Bleed flow offset (kg/h)

OfftakeMinimum Minimum bleed flow (kg/h)

OfftakeMaximum Maximum bleed flow (kg/h)

PressureDrop Pressure drop over bleed (bar)

DescribeCalculations Describe calculations

MaxConnectionCount Maximum possible connection count

Name The flow bleed name

Location The location text

Ignore The ignored flag: 0 = not ignored, 1=ignored

UpstreamConnection The name of the upstream pipe

UpstreamConnectionAt Code for the upstream pipe connection point

0 = upstream end, 1 = downstream end

DownstreamConnnection The name of the downstream pipe

DownstreamConnnectionAt Code for the downstream pipe connection point

0 = upstream end, 1 = downstream end

ConnectedCount Connection count

HorizontalSeparators

Attribute Description

LiquidLevel The liquid level (mm)

Diameter The vessel diameter (mm)

FittingLossMethod Code for fittings loss calculation: 0 = Ignored, 1 =Calculated

IsothermalPressureDrop Code for enabling isothermal pressure dropcalculations: 0 = No, 1 = Yes

TwoPhaseCorrection Code for two phase correction option: 0 = No, 1 = Yes

SwageMethod Code for size change calculation method: 0 =Compressible, 1 = Incompressible, 2 = Transition

CompressibleTransition DP percent of inlet pressure for transition (%)

BodyDimension Code for body area usage: 0 = Full body area, 1 =Partial body area on flow

ChokeMethod Choke flow check

CannotTear Cannot tear

DesignLength Design length

Ddrop Ddrop

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Attribute Description

DrainVol Drain volume

Holduptime Holdup time

Vsettling V settling

IsTear Is tear

PresBody Body pressure

TempBody Body temperature

VelBody Body velocity

DenBody Body density

DescribeCalculations Describe calculations

MaxConnectionCount Maximum possible connection count

Name The horizontal separator name

Ignore The ignored flag: 0 = not ignored, 1=ignored

Location The location text

UpstreamConnection The name of the upstream pipe

UpstreamConnectionAt Code for the upstream pipe connection point: 0 =upstream end, 1 = downstream end

BranchstreamConnection The name of the branch stream pipe

BranchstreamConnectionAt Code for the branch stream pipe connection point: 0 =upstream end, 1 = downstream end

DownstreamConnection The name of the downstream pipe

DownstreamConnectionAt Code for the downstream pipe connection point: 0 =upstream end, 1 = downstream end

ConnectedCount Connection count

OrificePlates

Attribute Description

FittingLossMethod Code for pressure loss method: 0 = Ignored, 1 = ThinPlate, 2 = Contraction/Expansion

IsothermalPressureDrop Code for enabling isothermal pressure drop calculations:0 = No, 1 = Yes

TwoPhaseCorrection Code for two phase correction option: 0 = No, 1 = Yes

SwageMethod Code for size change calculation method: 0 =Compressible, 1 = Incompressible, 2 = Transition=

CompressibleTransition DP percent of inlet pressure for transition (%)

DownstreamDiameterRatio Ratio of orifice to downstream diameter

UpstreamDiameterRatio Ratio of orifice to upstream diameter

Diameter Diameter of orifice (mm)

ChokeMethod Choke flow check

DescribeCalculations Describe calculations

MaxConnectionCount Maximum possible connection count

Name The orifice plate name

Location The location text

Ignore The ignored flag: 0 = not ignored, 1=ignored

UpstreamConnection The name of the upstream pipe

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Attribute Description

UpstreamConnectionAt The code for the upstream pipe connection point: 0 =upstream end, 1 = downstream end

DownstreamConnnection The name of the downstream pipe

DownstreamConnnectionAt The code for the downstream pipe connection point: 0 =upstream end, 1 = downstream end

ConnectedCount Connection count

Pipes

Attribute Description

LimitReached Reached limit or not

TailPipe Code to identify tailpipe: 0 = No, 1 = Yes

Sizeable Code for indicating sizeable pipe: 0 = No, 1 = Yes

UsePipeClass Code for pipe class usage: 0 = No, 1 = Yes

WallThickness Pipe wall thickness (mm)

InternalDiameter Pipe internal diameter (mm)

Schedule Pipe schedule

NominalDiameter Pipe nominal diameter

ThermalConductivity Pipe material thermal conductivity (W/m/C)

Roughness Pipe absolute roughness (mm)

Material Code for pipe material: 0 = Carbon steel, 1 =Stainless steel

ElevationChange Pipe elevation change (m)

Length Pipe length (m)

FittingsLossMultiply Fittings loss Ft factor

FittingsLossOffset Fittings loss offset

LengthMultiplier Multiplier for pipe length

MultipleElementCalculation Code for the multiple element heat transfercalculation: 0 = No, 1 = Yes

Emissivity The material fractional emissivity

ExternalRadiativeHTC Code for including radiative heat transfer: 0 = No, 1= Yes

HeatTransferEnabled Code to enable heat transfer calculations: 0 = No, 1= Yes

WindVelocity Wind speed (m/s)

Temperature Temperature outside pipe (C)

InsulationThermalConductivity Insulation thermal conductivity (W/m/C)

Thickness Insulation thickness (mm)

InsulationName Insulation description

Duty Duty (kJ/h)

OutletTemperatureSpecification Temperature leaving pipe (C)

DampingFactor Damping factor

VLEMethod Code for VLE method: 0 = Default, 1 = CompressibleGas, 2 = Peng Robinson, 3 = Soave Redlich Kwong,4 = Vapor Pressure

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Attribute Description

StaticHeadContribution Code for the static head contribution: 0 = Include, 1= Ignore Downhill Recovery, 2 = Ignore

FrictionFactorMethod Code for friction factor method: 0 = Default, 1 =Round, 2 = Chen

Elements Number of elements for pipe calculation

VerticalPipe Code for DP method for vertical pipes: 0 = Default, 1= Isothermal gas, 2 – Adiabatic gas, 3 =Beggs&Brill, 4 = Dukler, 5 = Orkisewski

InclinedPipeMethod Code for DP method for inclined pipes: 0 = Default,1 = Isothermal gas, 2 – Adiabatic gas, 3 =Beggs&Brill, 4 = Dukler

HorizontalPipeMethod Code for DP method for horizontal pipes: 0 =Default, 1 = Isothermal gas, 2 – Adiabatic gas, 3 =Beggs&Brill, 4 = Dukler

ExternalMedium Code for the external medium: 0 = Air, 1 = SeaWater

RoughnessForFitting Roughness for fitting

Klocked K locked

Kusing K using

CalcStatus Calculation status

FittingCount Number of fittings linked to this pipe

PhysicalLength Physical length

MaxConnectionCount Maximum possible connection count

Name Name

Ignore The ignored flag: 0 = not ignored, 1=ignored

Location The location text

DescribeCalculations Describe calculations

UpstreamConnection The name of the upstream node

UpstreamConnectionAt Code for the upstream node connection point: 0,1,2depending on upstream node

DownstreamConnnection The name of the downstream node

DownstreamConnnectionAt Code for the downstream pipe connection point:0,1,2 depending on downstream node

ConnectedCount Connection count

Fitting

Attribute Description

ItemName The name of the fitting

ID Description of the fitting

KOffset Fitting loss constant

KMultiplier Fitting loss Ft factor

ReliefValves

Attribute Description

MAWP Maximum allowable working pressure (bar a)

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Attribute Description

MechPres Mechanical pressure limit (bar a)

ValveType Type code for valve: 0 = Balanced, 1 =Conventional

OrificeType Standard type code for orifice

ValveArea Area of each valve orifice (mm2)

ValveCount Number of valves

IsenTropicFlash Isentropic flash

DescribeCalculations Describe calculations

MaxConnectionCount Maximum possible connection count

Ignore Ignore flag

KMultiply Fittings loss Ft factor for inlet pipe

KOffset Fittings loss offset for inlet pipe

FlangeDiameter Internal diameter of flange (mm)

ElevationChange The elevation change of the inlet piping (m)

Length The length of the inlet piping (m)

InternalDiameter The inlet pipe diameter (mm)

Schedule The inlet pipe schedule

NominalDiameter The inlet pipe nominal diameter

Roughness The inlet pipe roughness (mm)

Material Code for the inlet pipe material: 0 = Carbon Steel,1 = Stainless steel

Thickness Thickness

UsePipeClass Code for enabling pipe class usage: 0 = No, 1 =Yes

Name The relief valve name

Location The location text

UpstreamConnnection The name of the upstream pipe

UpstreamConnnectionAt Code for the upstream pipe connection point: 0 =upstream end, 1 = downstream end

ConnectedCount Connection count

Tees

Attribute Description

Body Code for body type: 0 = Run, 1 = Tail, 2 = Branch, 3= Auto

Theta Code for branch angle: 0 = 30 deg, 1 = 45 deg, 2 =60 deg, 3 = 90 deg

ThetaAsReal Theta as real

FittingLossMethod Code for fittings loss calculation: 0 = Ignored, 1 =Simple, 2 = Miller

MillerChartExtrapolation Code for Miller chart extrapolation: 0 = None, 1 =Miller Ratio Squared, 2 = Gardel

ConnectorIfIncomplete Code to use connector calculation: 0 = No, 1 = Yes

IsothermalPressureDrop Code for enabling isothermal pressure dropcalculations: 0 = No, 1 = Yes

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Attribute Description

TwoPhaseCorrection Code for two phase correction option: 0 = No, 1 =Yes

SwageMethod Code for size change calculation method: 0 =Compressible, 1 = Incompressible, 2 = Transition

CompressibleTransition DP percent of inlet pressure for transition (%)

BodyDimension Code for body area usage: 0 = Full body area, 1 =Partial body area on flow

ChokeMethod Choke flow check

Orientation Orientation

Separate Separate

CannotTear Cannot tear

DescribeCalculations Describe calculations

MaxConnectionCount Maximum possible connection count

Name The tee name

Location The location text

Ignore The ignored flag: 0 = not ignored, 1=ignored

UpstreamConnection The name of the upstream pipe

UpstreamConnectionAt Code for the upstream pipe connection point: 0 =upstream end, 1 = downstream end

BranchstreamConnection The name of the branch stream pipe

BranchstreamConnectionAt Code for the branch stream pipe connection point: 0= upstream end, 1 = downstream end

DownstreamConnection The name of the downstream pipe

DownstreamConnectionAt Code for the downstream pipe connection point: 0 =upstream end, 1 = downstream end

ConnectedCount Connection count

FlareTips

Attribute Description

Diameter Diameter of flare (mm)

CompressibleTransition DP percent of inlet pressure for transition (%)

Method Method

TwoPhaseCorrection Code for two phase correction option: 0 = No, 1 = Yes

IsothermalPressureDrop Code for enabling isothermal pressure drop calculations:0 = No, 1 = Yes

FittingLossCoefficient Fittings loss coefficient

FittingLossCoefficientBasis Code for fittings loss basis: 0 = Total pressure, 1 =static pressure

UseCurves Code for curve usage: 0 = No, 1 = Yes

NumCurves Number of pressure drop curves

FlowExtrapolation Flow extrapolation

MolWtExtrapolation Molecular weight extrapolation

PressureCorrection Pressure correction

RefTemp Reference temperature for curve data (C)

Sizeable Code for indicating sizeable pipe

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Attribute Description

UsePipeClass Code for enabling Pipe Class usage

WallThickness Wall thickness

InternalDiameter Internal diameter

Schedule Pipe schedule

NominalDiameter Pipe nominal diameter

ThermalConductivity Pipe material thermal conductivity (W/m/C)

Roughness Pipe roughness

Material Code for the inlet pipe material

ChokeMethod Choke flow check

DescribeCalculations Describe calculations

MaxConnectionCount Maximum possible connection count

Name The flare tip name

Location The location text

Ignore The ignored flag: 0 = not ignored, 1=ignored

UpstreamConnection The name of the upstream pipe

UpstreamConnectionAt Code for the upstream pipe connection point: 0 =upstream end, 1 = downstream end

ConnectedCount Connection count

Curves

Attribute Description

TipName The name of the top (30 chars)

MolWt The reference molecular weight for the curve

CurveNumPoints The number of points in the curve

Points

Attribute Description

CurveDataPointNo The number of the curve data point

MolWt The mole weight of the curve

MassFlow The mass flow for the curve data point (kg/h)

PresDrop The pressure drop for the curve data point (bar)

VerticalSeparators

Attribute Description

Diameter The vessel diameter (mm)

FittingLossMethod Code for fittings loss calculation: 0 = Ignored, 1 =Calculated

IsothermalPressureDrop Code for enabling isothermal pressure drop calculations:0 = No, 1 = Yes

TwoPhaseCorrection Code for two phase correction option: 0 = No, 1 = Yes

SwageMethod Code for size change calculation method: 0 =Compressible, 1 = Incompressible, 2 = Transition

CompressibleTransition DP percent of inlet pressure for transition (%)

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Attribute Description

ChokeMethod Choke flow check

DesignDiameter Design diameter

Ddrop Ddrop

Vsettling V settling

PresBody Body pressure

TempBody Body temperature

VelBody Body velocity

DenBody Body density

DescribeCalculations Describe calculations

MaxConnectionCount Maximum possible connection count

Name The vertical separator name

Location The location text

Ignore The ignored flag: 0 = not ignored, 1=ignored

UpstreamConnection The name of the upstream pipe

UpstreamConnectionAt Code for the upstream pipe connection point: 0 =upstream end, 1 = downstream end

DownstreamConnection The name of the downstream pipe

DownstreamConnectionAt Code for the downstream pipe connection point: 0 =upstream end, 1 = downstream end

ConnectedCount Connection count

Scenarios

Attribute Description

Name The scenario name (30 chars)

OptionVelConstr Option velocity constraint

Done Done

HeaderMach Header mach number limit

HeaderVapVel Header vapor velocity limit (m/s)

HeaderLiqVel Header liquid velocity limit (m/s)

HeaderRV2 Header momentum limit (kg/m/s2)

HeaderNoise Header noise limit (dB)

TailPipeMach Tailpipe mach number limit

TailPipeVapVel Tailpipe vapor velocity limit (m/s)

TailPipeLiqVel Tailpipe liquid velocity limit (m/s)

TailPipeRV2 Tailpipe momentum limit (kg/m/s2)

TailPipeNoise Tailpipe noise limit (dB)

Pressure System back pressure (bar a)

CalculateMe Calculate me

SolverOptions

Attribute Description

AmbientTemperature External temperature (C)

AtmosphericPressure Atmospheric pressure (bar a)

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Attribute Description

CheckChoke Check for choke flow: 0 = No, 1 = Yes

Choke Code for choke calculation method: 0 = Simple, 1 =HEM

HeatTransfer Enable heat transfer calculations: 0 = No, 1 = Yes

ExternalRadiation External radiation

Mode Code for calculation mode: 0 = Rating, 1 = Design, 2= Debottleneck

RatedFlow Use rated flow for inlet pipes

RatedFlowNodes Use rated flow for downstream nodes attached totailpipes

RatedFlowTailPipe Use rated flow for tailpipes: 0 = No, 1 = Yes

WindSpeed Wind velocity (m/s)

UseKineticEnergy Include kinetic energy: 0 = No, 1 = Yes

IgnoreSepKineticEnergy Ignore kinetic energy in separators: 0 = No, 1 - Yes

KineticEnergyBasis Code for kinetic energy basis: 0 = Inlet Pipe Velocity,1 = Zero velocity

CalcIgnoredSources Calculate ignored sources as zero flow: 0 = No, 1 =Yes

MabpForInactiveValves Check MABP for inactive sources: 0 = No, 1 = Yes

IgnoreSourceSizeChangeWhenSizing

Ignore valve flange size change in design calculations:0 = No, 1 = Yes

MaxmumSystemVelocity Maximum system velocity

AllScenarios Code to indicate which scenarios are calculated: 0 =Current, 1 = All, 2 = Selected

VLE Code for VLE method: 0 = Compressible gas, 1 =Peng Robinson, 2 = Soave Redlich Kwong, 3 = VaporPressure

Enthalpy Code for enthalpy method: 0 = Ideal gas, 1 =PengRobinson, 2 = Soave Redlich Kwong, 3 = LeeKesler

VleSourceOutletTemp VLE source outlet temperature

EnthalpySourceOutletTemp Enthalpy source outlet temperature

Horizontal Code for horizontal pressure drop method: 0 =Isothermal gas, 1 = Adiabatic Gas, 2 = Beggs&Brill 3= Dukler

Inclined Code for inclined pressure drop method: 0 =Isothermal gas, 1 = Adiabatic Gas, 2 = Beggs&Brill 3= Dukler

Vertical Code for vertical pressure drop method: 0 =Isothermal gas, 1 = Adiabatic Gas, 2 = Beggs&Brill 3= Dukler, 4 = Orkisewski

Elements Number of elements for two phase calculations

FrictionFactor Code for friction factor method: 0 = Round, 1 = Chen

UsePipeRoughnessForFitting Use pipe roughness for fitting

RoughnessForFitting Roughness for fitting

WarnMachForSizing Warn Mach for sizing

WarnVelocityForSizing Warn velocity for sizing

WarnRhoV2ForSizing Warn RhoV2 for sizing

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Attribute Description

WarnNoiseForSizing Warn noise for sizing

WarnIceFormForSizing Warn Ice form for sizing

WarnBPForSizing Warn BPF for sizing

WarnChokeForSizing Warn choke flow for sizing

WarnSlugForSizing Warn slug flow for sizing

WarnTempForSizing Warn temperature for sizing

WarnPressureBasis Warn pressure basis

WarnPhysPropFailure Warn physical properties failure

WarnHeatBalanceFailure Warn heat balance failure

WarnChokePresFailure Warn choke pressure failure

WarnPresDropFailure Warn pressure drop failure

WarnLiqWithVapMethodFailure

Warn liquid with vapour only method failure

WarnCorrRangeFailure Warn correlation out of range failure

WarnInitWhileSizing Warn initialization while sizing

WarnSizeChangeWhileSizing Warn size change while sizing

WarnLimitReachedWhileSizing

Warn limit reached while sizing

PresTolProperties Pressure tolerance in properties loop (%)

PresTolUnitOp Pressure tolerance for unit operation calculations (%)

PresTolLoop Pressure tolerance for loop calculations (%)

MassToLoop Mass balance tolerance in outer loop (%)

IterationsProperties Number of iterations in inner (properties) loop

IterationsLoop Number of iterations for loop calculations

DamperProperties Damping factor for inner (properties) loop

DamperLoop Damping factor for loop calculations

LoopMethod Select loop convergence method: 0=Newton Raphson,1=Broyden, 2=Force Convergent

LoopAnalyser Select analyzer for looped systems: 0 = Convergent, 1= Simultaneous

EchoLoops Are loop calculations echoed: 0 = No, 1 = Yes

KeepBad Keep bad

UpdateEstimates Update flow estimates from solution: 0 = No, 1 = Yes

InitalPressure Initial pressure for property calculations (bar a)

LengthMultiplier Pipe length multiplication factor

InitPhaseMethodForSizing Initialization phase method for sizing

UpstreamMinTemp Upstream minimum temperature

DownstreamMinTemp Downstream minimum temperature

UpstreamMaxTemp Upstream maximum temperature

DownstreamMaxTemp Downstream maximum temperature

InletFlowCheck Inlet flow check

GaugeInletCheck Gauge inlet check

IgnoreInlet Ignore inlet

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SourceData

Attribute Description

ScenarioName The name of the scenario

SourceName The name of the source

MassFlow Mass flow of the source (kg/h)

Ignored The ignored flag: 0 = not ignored, 1=ignored

PresAllow Allowable pressure

OutletTemperature Outlet temperature (C)

InletTemp Inlet temperature

InletTempSpec Inlet specified temperature value (C)

InletPressure Inlet pressure

LockMABP Auto update of MABP: 0 = No, 1 = Yes

VLEMethod Code for VLE method: 0 = Model default, 1 =Compressible gas, 2 = Peng Robinson, 3 = SoaveRedlich Kwong, 4 = Vapor Pressure

FittingLossMethod Code for fitting loss calculation: 0 = Ignored, 1 =Calculated

IsothermalPressureDrop Code for enabling isothermal pressure dropcalculations: 0 = No, 1 = Yes

TwoPhaseCorrection Code for two phase correction option: 0 = No, 1 =Yes

SwageMethod Code for size change calculation method: 0 =Compressible, 1 = Incompressible, 2 = Transition

CompressibleTransition DP percent of inlet pressure for transition (%)

VapourFraction Vapour fraction

VapourMolWt Vapour molecular weight

IsentropicEfficiency Isentropic efficiency

SizingMethod Code for PSV sizing method: 0 = API, 1 = HEM

BackPressure Back pressure

MultiPhaseCd Multi-phase Cd

LiquidCd Liquid Cd

Kb Kb

RuptureDisk Rupture disk

PresCalc Static pressure

DenCalc Calculated density

VelCalc Velocity

TempCalc Temperature

ChokeMethod Choke flow check

Energy Energy

Enthalpy Enthalpy

Entropy Entropy

Quality Quality

Tempincalc Calculated inlet temperature

SonicCalc Calculated sonic

NonRecoverablePresDrop Piping non-recoverable pressure drop

InletVelocity Inlet velocity

Page 217: Flarenet modelling

A File Format 211

Attribute Description

InletDensity Inlet density

StaticPresDrop Static pressure drop

TotalPresDrop Total pressure drop

HasProblem Has problem flag

HeaderVapourFraction Header vapour fraction

HeaderVapourMolWt Header vapour molecular weight

HasProblemDp Constraint violation: pressure drop

HasProblemVel Constraint violation: velocity

HasProblemMach Constraint violation: Mach number

HasProblemChoke Constraint violation: choke

HasProblemRhoV2 Constraint violation: RhoV2

HasProblemPres Constraint violation: pressure

HasProblemTemp Constraint violation: temperature

VfCalc Vf calculation

StagnationEnthalpy Stagnation enthalpy

StagnationEnthalpyCalc Calculated stagnation enthalpy

FlowPathCount Flow path count

FlowPathName Flow path name

FlowPathType Flow path type

RatedFlow Rated flow of the source (kg/h)

Contingency Code for sizing contingency: 0 = Operating, 1 = Fire

LockRatedFlow Auto update of rated flow: 0 = No, 1 = Yes

LockReliefPressure Auto update of relieving pressure: 0 = No, 1 = Yes

CpCvRatio Cp Cv ratio

Compressibility Compressibility

InletPresTotalCalc Total inlet pressure

PresTotalCalc Total pressure

MachNo Mach number

RhoV2Calc Rho V2

MolarFlow Molar flow

MolWt Fluid molecular weight

StaticPresDropForSummary Valve static pressure drop

TotalPresDropForSummary Valve total pressure drop

Composition

Attribute Description

ScenarioName The name of the scenario

SourceName The name of the source

FluidType Fluid type

Basis Code for composition input basis: 0 = MolWt, 1 = Molefraction, 2 = Mass fraction

MolWt Molecular weight

Page 218: Flarenet modelling

212 A File Format

PFDLayout

Attribute Description

ItemName The name of the PFD item

XPosition The X coordinate of the item

YPosition The Y coordinate of the item

LabelXPosition The X coordinate of the item label

LabelYPosition The X coordinate of the item label

RotationFlipType Code for icon rotation: 0 = None, 1 = Rotate 90°, 2 = Rotate180°, 3 = Rotate 270°, 4 = Flip X, 5 = Rotate 90° + Flip Y, 6 =Flip Y, 7 = Rotate 90° + Flip X

Results

Attribute Description

ScenarioName The name of the scenario

SegmentName The name of the pipe segment

MolWt Molecular weight

MolarFlow Molar weight

MassFlow The mass flow (kg/h)

UpstreamTestFlow Test flow of upstream

DownstreamTestFlow Test flow of downstream

dp_F Pressure drop due to friction (bar)

dp_A Pressure drop due to acceleration (bar)

dp_E Pressure drop due to elevation change (bar)

dp Pressure drop

Noise Noise (dB)

HtcInternal Internal heat transfer coefficient (W/m2/C)

HtcConvExternal External heat transfer coefficient (W/m2/C)

HtcOverall Overall heat transfer coefficient (W/m2/C)

UpstreamVelocityNonRated Upstream non-rated velocity

DownstreamVelocityNonRated Downstream non-rated velocity

UpstreamVelocityRated Upstream rated velocity

DownstreamVelocityRated Downstream rated velocity

UpstreamVelocity Velocity at upstream end of pipe (m/s)

DownstreamVelocity Velocity at downstream end of pipe (m/s)

UpstreamSonicVelocity Upstream sonic velocity

DownstreamSonicVelocity Downstream sonic velocity

UpstreamPresTotalNonRated Upstream total non-rated pressure

DownstreamPresTotalNonRated Downstream total non-rated pressure

UpstreamPresTotalRated Upstream total rated pressure

DownstreamPresTotalRated Downstream total rated pressure

UpstreamPresTotal Upstream total pressure

DownstreamPresTotal Downstream total pressure

UpstreamPresStatic Upstream static pressure

DownstreamPresStatic Downstream static pressure

Page 219: Flarenet modelling

A File Format 213

Attribute Description

UpstreamTemperature Temperature at upstream end of pipe (C)

DownstreamTemperature Temperature at downstream end of pipe (C)

UpstreamEnthalpy Energy at upstream end of pipe (kJ/kgmole)

DownstreamEnthalpy Energy at downstream end of pipe (kJ/kgmole)

UpstreamDensity Density at upstream end of pipe (kg/m3)

DownstreamDensity Density at downstream end of pipe (kg/m3)

UpstreamFlowRegime Flow regime at upstream end of pipe

DownstreamFlowRegime Flow regime at downstream end of pipe

CanCalc Can calculate

Duty Heat transferred (kJ/h)

FrictionFactor Friction factor

Dp_Fittings Pressure drop due to fittings (bar)

RatedFlow The rated flow (kg/h)

ReynoldsNonRated Reynolds non-rated

ReynoldsRated Reynolds rated

Reynolds Reynolds number

SourcePres Pressure of attached source node (bar a)

Equivlength Equivalent length (m)

UpstreamEnergy Energy at upstream end of pipe (kJ/h)

DownstreamEnergy Energy at downstream end of pipe (kJ/h)

UpstreamEnthalpyEnergy Upstream enthalpy energy

DownstreamEnthalpyEnergy Downstream enthalpy energy

UpstreamMachNoNonRated Upstream non-rated Mach number

DownstreamMachNoNonRated Downstream non-rated Mach number

UpstreamMachNoRated Upstream rated Mach number

DownstreamMachNoRated Downstream rated Mach number

UpstreamMachNo Mach number at upstream end of pipe

DownstreamMachNo Mach number at downstream end of pipe

UpstreamPresProp Upstream pressure property

DownstreamPresProp Downstream pressure property

UpstreamRhoV2NonRated Upstream non-rated Rho V2

DownstreamRhoV2NonRated Downstream non-rated Rho V2

UpstreamRhoV2Rated Upstream rated Rho V2

DownstreamRhoV2Rated Downstream rated Rho V2

UpstreamRhoV2 Momentum at upstream end of pipe (kg/m/s2)

DownstreamRhoV2 Momentum at downstream end of pipe (kg/m/s2)

UpstreamVapourFraction Upstream vapour fraction

DownstreamVapourFraction Downstream vapour fraction

UpstreamProbChoked Upstream probable choked

DownstreamProbChoked Downstream probable choked

UpstreamProbMachNo Upstream probable Mach number

DownstreamProbMachNo Downstream probable Mach number

ProbNoise Probable noise

Page 220: Flarenet modelling

214 A File Format

Attribute Description

ProbSourcePres Probable source pressure

ProbSource Probable source

UpstreamProbRhoV2 Upstream probable Rho V2

DownstreamProbRhoV3 Downstream probable Rho V2

ProbSlugs Probable slug flows

UpstreamProbTemp Upstream probable temperature

DownstreamProbTemp Downstream probable temperature

UpstreamProbVelLiq Upstream probable liquid velocity

DownstreamProbVelLiq Downstream probable liquid velocity

UpstreamProbVelVap Upstream probable vapour velocity

DownstreamProbVelVap Downstream probable vapour velocity

PresBody Body pressure

DenBody Body density

VelBody Body velocity

Estimate Estimate

CannotTear Cannot tear

WallTemperature Temperature of pipe wall (C)

MaxStep Maximum step

MaxFlow Maximum flow

MinFlow Minimum flow

HtcRadExt External radiative HTC

ExtTemperature External temperature

UpstreamVelLiqNonRated Upstream non-rated liquid velocity

DownstreamVelLiqNonRated Downstream non-rated liquid velocity

UpstreamVelLiqRated Upstream rated liquid velocity

DownstreamVelLiqRated Downstream rated liquid velocity

UpstreamVelLiq Upstream liquid velocity

DownstreamVelLiq Downstream liquid velocity

UpstreamVelVapNonRated Upstream non-rated vapour velocity

DownstreamVelVapNonRated Downstream non-rated vapour velocity

UpstreamVelVapRated Upstream rated vapour velocity

DownstreamVelVapRated Downstream rated vapour velocity

UpstreamVelVap Upstream vapour velocity

DownstreamVelVap Downstream vapour velocity

PresDrop Pressure drop over pipe (bar)

UpstreamPressure Pressure at upstream end of pipe (bar a)

DownstreamPressure Pressure at downstream end of pipe (bar a)

TotalPresDrop Total pressure drop

EquivlengthForPipeSummary Equivalent length

Phase

Attribute Description

ScenarioName The name of the scenario

Page 221: Flarenet modelling

A File Format 215

Attribute Description

SegmentName The name of the pipe segment

SegmentEnd End of the pipe segment

Phase Phase description

Density Density of the phase (kg/m3)

Enthalpy Energy of the phase (kJ/kgmole)

Entropy Entropy of the phase (kJ/kgmole/K)

Fraction Fraction of the phase

HeatCap Heat capacity of the phase (kJ/kgmole/K)

MolWt Mol Wt of the phase

SurfTen Surface tension of the phase (dyne/cm)

ThermCond Thermal conductivity of the phase (W/m/K)

Viscosity Viscosity of the phase (cP)

ZFactor Z Factor of the phase

CompResults

Attribute Description

ScenarioName The name of the scenario

SegmentName The name of the pipe segment

FluidType Fluid type

Basis Basis

MolWt The molecular weight of the fluid

Fraction The mole fraction of each component

Report File FormatsThe printouts can be customized to a limited extent using a XML file with theextension “.xml”. This file may be edited using any ASCII text editor such asthe NOTEPAD application distributed with Microsoft Windows.

The default “.xml” file for the printed reports is: ReportFormat.xml

By default, the report format file is located in the Aspen Flare SystemAnalyzer program directory. You can change the location and “.xml“ file forthe reports on the Reports tab on the Preferences Editor.

Page 222: Flarenet modelling

216

Fig A.1

The following defines which variable may be printed with each report:

Variable Name

ambient

backpres

basis

class

conductivity

connections

densitydown

densityup

description

dsn

duty

elevation

energy

energyflowdown

The following defines which variable may be printed with each report:

Variable Description

Ambient temperature

Back pressure

Composition basis

Pipe class

Thermal conductivity

Item connections

Downstream density

Upstream density

Description

Downstream node

Heat loss

Elevation change

Energy

Downstream energy flow

A File Format

The following defines which variable may be printed with each report:

Page 223: Flarenet modelling

A File Format 217

Variable Name Variable Description

energyflowup Upstream energy flow

enthalpy Enthalpy

enthalpyflowdown Downstream enthalpy flow

enthalpyflowup Upstream enthalpy flow

enthalpyup Upstream enthalpy

enthalpydown Downstream enthalpy

entropy Entropy

entropydown Downstream entropy

entropyup Upstream entropy

equivlength Equivalent length

exttemperature External temperature

fittinglist Fitting list

fittingsa Fitting loss A

fittingsb Fitting loss B

flange Flange diameter

fractiondown Downstream phase fraction

fractionup Upstream phase fraction

frictionfractor Friction factor

group Item group

headmach Header mach number

headvelvap Header vapor velocity

headvelliq Header liquid velocity

headrhov2 Header rho V2

headnoise Header noise

heatcapdown Downstream heat capacity

heatcapup Upstream heat capacity

hia Enthalpy A coefficient

hib Enthalpy B coefficient

hic Enthalpy C coefficient

hid Enthalpy D coefficient

hie Enthalpy E coefficient

hif Enthalpy F coefficient

htcradext External radiative HTC

htcoverall Overall HTC

htcexternal External HTC

htcinternal Internal HTC

id Item ID

ignored Item ignored

inletlength Inlet pipe length

Page 224: Flarenet modelling

218 A File Format

Variable Name Variable Description

inletelevation Inlet pipe elevation change

inletmaterial Inlet pipe material

inletroughness Inlet pipe roughness

inletnominal Inlet pipe nominal diameter

inletschedule Inlet pipe schedule

inletinternal Inlet pipe internal diameter

inletclass Inlet pipe class

Inletfittingsa Inlet pipe fitting loss A

Inletfittingsb Inlet pipe fitting loss B

insname Insulation description

insthick Insulation thickness

insconductivity Insulation conductivity

internal Internal diameter

length Segment length

lmultiply Length multiplier

location Segment location

machdown Downstream mach number

machup Upstream mach number

massflow Mass flow

material Material of construction

methoddamping Damping factor

methodelements Two phase elements

methodfriction Friction factor

methodfitlos Fitting loss method

methodhordp Horizontal 2 phase pressure drop method

methodincdp Inclined pressure drop

methodverdp Vertical 2 phase pressure drop method

methodvle VLE method

molarflow Molar flow

molwt Molecular weight

molwtdown Downstream molecular weight

molwtup Upstream molecular weight

multiply Fittings equation multiplier

name Item name

nbp Normal boiling point

node Node

nodetype Node type

noise Noise

nominal Nominal pipe diameter

Page 225: Flarenet modelling

A File Format 219

Variable Name Variable Description

number Index number

offset Fittings equation offset

omega Acentric factor

omegasrk SRK acentric factor

orificearea Orifice area

orifice Orifice

pc Critical pressure

phase Phase label

pressource Static source back pressure

presallow Allowable back pressure

presdown Downstream static pressure

presdrop Pressure drop

presdropfriction Static pipe friction loss

presdropacceleration Static pipe acceleration loss

presdropelevation Static pipe elevation loss

presdropfittings Static pipe fitting loss

presin Inlet pressure

preslimit Back pressure limit

presup Upstream static pressure

ratedflow Rated mass flow

refer Literature reference

regime Flow regime

resize Resizable flag

reynolds Reynolds number

rhov2up Upstream rho V2

rhov2down Downstream rho V2

roughness Wall roughness

schedule Pipe schedule

si Entropy coefficient

stddensity Standard density

surftendown Downstream surface tension

surftenup Upstream surface tension

tailmach Tailpipe mach No.

tailnoise Tailpipe noise

tailpipe Tailpipe flag

tailrhov2 Tailpipe rho V2

tailvelliq Tailpipe liquid velocity

tailvelvap Tailpipe vapor velocity

tc Critical temperature

Page 226: Flarenet modelling

220 A File Format

Variable Name Variable Description

tempcalc Inlet temperature calculations

tempdown Downstream temperature

tempout Outlet temperature

tempspec Inlet temperature specification

tempup Upstream temperature

thermconddown Downstream thermal conductivity

thermcondup Upstream thermal conductivity

type Item type

usn Upstream node

valvecount Number of valves

valvetype Valve type

vapfrac Source vapor fraction

vc Critical volume

vchar Characteristic volume

veldown Downstream velocity

velup Upstream velocity

visca Viscosity A coefficient

viscb Viscosity B coefficient

viscdown Downstream viscosity

viscup Upstream viscosity

wall Wall thickness

walltemperature Wall temperature

watson Watson characterisation parameter

wind Wind velocity

zfactordown Downstream compressibility factor

zfactorup Upstream compressibility factor

Page 227: Flarenet modelling

B References 221

B References

1 “GPSA Engineering Data Book”.

2 “Chemical Engineering Volume 1”, J. M. Coulson and J. F. Richardson,Pergamon Press, 2nd Edition.

3 “Viscosity of Gases And Mixtures”, I. F. Golubev, National TechnicalInformation Services, TT7050022, 1959.

4 “Chemical Process Computations 1, Chemical Engineering-DataProcessing”, Raman, Raghu, Elsevier Applied Science Publishers Ltd, 1985.

5 “Journal Of Physics”, D. J. Berthalot, P.3 ,263.

6 “Technical Data Book-Petroleum Refining”, American Petroleum Institute,1977.

7 “A Computer Program for the Prediction of Viscosity and ThermalConductivity in Hydrocarbon Mixtures”, J.F. Ely and H.J.M. Hanley, NBSTechnical Note, 1039, 1983.

8 R.W. Hankinson and G.H. Thompson, AIChE Journal, 25, 653, 1979.

9 “A Study of Two-Phase Flow in Inclined Pipes”, H.D. Beggs and J.P. Brill, J.Petrol. Technol., P. 607, May, 1973.

10 “Gas Conditioning and Processing”, R. N. Maddox and L. L. Lilly, Volume 3,1982 by Campbell Petroleum Series, 2nd edition, 1990.

11 J. Orkiszewski, Journal of Petroleum Technology, B29-B38, June, 1967.

12 “Gas Conditioning and Processing”, R. N. Maddox and L. L. Lilly, Volume 3,1982 by Campbell Petroleum Series, 2nd edition, 1990.

13 API Technical Data Book Volume 1, American Petroleum Institute, 1983.

14 R.W. Hankinson and G.H. Thompson, A.I.Ch.E. Journal, 25, No. 4, P.6531979.

15 “The Properties of Gases &Liquids”, R.C. Reid, J.M. Prausnitz and B.E.Poling, McGraw-Hill, Inc., 1987.

16 “A Computer Program for the Prediction of Viscosity and ThermalConductivity in Hydrocarbon Mixtures”, J.F. Ely and H.J.M. Hanly, NBSTechnical Note 1039.

17 “Molecular Thermodynamics of Fluid Phase Equilibria”,J.M. Pausnitz, R.N.Lichtenthaler and E.G. Azevedo, 2nd Edition, McGraw-Hill, Inc. 1986.

18 C.H. Twu, IEC. Proc Des & Dev, 24, P. 1287, 1985.

19 “Viscosity of Crude-Oil Emulsions”, W. Woelfin, Spring Meeting, PacificCoast District, Division of Production, Los Angeles, Calif., Mar. 10, 1942.

20 W.R. Gambill, Chem Eng., March 9, 1959.

Page 228: Flarenet modelling

222 B References

21 “An Explicit Equation for Friction Factor in Pipe”, N.H. Chen, Ind. Eng.Chem. Fund., 18, 296, 1979.

22 “Sizing, Selection, and Installation of Pressure - Relieving Devices inRefineries”, API Recommended Practice 520, Part I, 6th Edition, AmericanPetroleum Institute, March, 1993.

23 “Guide for Pressure-Relieving and Depressuring Systems”, APIRecommended Practice 521, 3rd Edition, American Petroleum Institute,November, 1990.

24 “Easily Size Relief Devices and Piping for Two-Phase Flow”, J.C. Leung,Chem. Eng. Prog., P. 28, December, 1996.

25 “Internal Flow Systems”, D.M. Miller, 2nd Edition, BHR Group Limited,1990.

26 “Flow of Fluids Through Valves, Fittings and Pipe”, Crane Technical Paper410M. 1988.

27 “PIPE 3, Single and Two-Phase Pressure Drop Calculations in PipelineSystems”, HTFS Design Report 38, 1996.

28 “Les Pertes de Charges dans les Écoulements au Travers de”, A. Gardel,Bulletin Technique de la Suisse Romande, 83, 1957.

Page 229: Flarenet modelling

C Glossary of Terms 223

C Glossary of Terms

Adiabatic FlowAdiabatic flow is the constant enthalpy flow of a fluid in a pipe.

Choked FlowThe velocity of a fluid in a pipe of constant cross-sectional area cannot exceedthe sonic velocity of the fluid. If the flow of fluid in a pipe is great enough thatthe sonic velocity is reached, then a pressure discontinuity is seen at the exitend of the pipe.

Critical PressureThe critical pressure is the pressure at which the vapor density and liquiddensity of a substance may be the same.

Critical TemperatureThe critical temperature is the temperature at which the vapor density andliquid density of a substance may be the same.

DongleSee Security Device.

Equivalent LengthThe equivalent length of a pipe is the straight length of pipe which wouldcreate the same pressure drop as the actual pipe length plus losses due tobends and fittings.

Page 230: Flarenet modelling

224 C Glossary of Terms

Isothermal FlowIsothermal flow is the constant temperature flow of a fluid in a pipe. Ingeneral when the pressure of a gas reduces, there is a small change intemperature. This assumption leads to a small error in the calculated pressureprofile. In practice, for pipes of length at least 1000 diameters, this differencedoes not exceed 5% and in fact never exceeds 20%.

MABPThe Maximum Allowable Back Pressure on a relief device is the maximumpressure that can exist at the outlet of the device without affecting thecapacity of the device.

In general the MABP for a conventional pressure relief valve should notexceed 10% of the set pressure at 10% overpressure.

In general the MABP for a balanced pressure relief valve should not exceed40% of the set pressure at 10% overpressure.

Mach NumberMach number is the ratio of the fluid velocity to the sonic velocity in the fluid.

NodeNodes define the connection points between pipes, and pipes with sources.Each node must have a unique name.

Reduced PressureReduced pressure is the ratio of the absolute pressure to the critical pressureof the fluid.

Reduced TemperatureReduced temperature is the ratio of the absolute temperature to the criticaltemperature of the fluid.

ScenarioA scenario represents a set of flow and compositional data for all sources inthe system. It may also represent a particular set of limiting operatingconditions.

Page 231: Flarenet modelling

C Glossary of Terms 225

ScheduleThe schedule of a pipe defines a standard thickness for a given nominal pipesize. In general, flare and vent systems are constructed from schedule 40 or80 pipe.

Security DeviceThe hardware device that is connected to the parallel port of the computer.

SourceA source refers to a fluid entering the piping network regardless of the type ofpipe fitting from which it enters. the fluid is defined in terms of itscomposition, mass flowrate, pressure and temperature.

Static PressureThe pressure acting equally in all directions at a point in the fluid.

Physical properties are calculated at the static pressure condition.

TailpipeThe section of pipe between the discharge flange of the source valve and themain collection header is generally referred to as a tailpipe.

Total PressureThe sum of the static and velocity pressures.

Velocity Pressure

Given by2

ρU2

, also called the kinematic pressure.

Page 232: Flarenet modelling

226 Index

Index

A

Automation 115

B

binary interaction parameters 11

C

calculationssizing 104speed 103status 101stop 101type 101

Component Editor 6Component Manager 3components

binary interaction parameters 11changing 11combining 11estimating unknown properties 10list 4name string 5selecting 4selection filter 5type 4updating with user data 10

Connector 43Control Valve 71

D

dataadding/deleting 109filters 108printing 109protection 110tables 109

Database Editor

Page 233: Flarenet modelling

Index 227

component 112fittings 112pipe schedule 110

database featuresadding/deleting data 109grid controls 108

F

Flare Tip 95Flow Bleed 47

H

Horizontal Separator 50

M

modeling flare networksprimary objectives 102recommended sequence 102

N

Node Manager 41nodes

Connector 43Control Valve 71Flare Tip 95Flow Bleed 47Horizontal Separator 50Orifice Plate 56Relief Valve 81Tee 60Vertical Separator 65

Nodes 41noise 186

O

Orifice Plate 56

P

passwordsetting 110

physical properties 178Pipe Class Editor 39Pipe Manager 25pipes

multiple editing 38Pipe Class 39

pressure drop methods 157

Page 234: Flarenet modelling

228 Index

R

Relief Valve 81

S

Scenario Editor 17Scenario Manager 16scenario selector 16scenarios 15

adding single source 23adding/editing 17tools 23

sizingrecommended procedure 104

source tools 94adding single source scenarios 95updating downstream temperatures 95

sourcesControl Valve 71Relief Valve 81tools 94

Status bar 101

T

Tee 60

V

vapour-liquid equilibrium 175Vertical Separator 65VLE method 103