on-line performance monitoring - gpilearn connect resources/real time...art on-line performance...

REAL-TIME PERFORMANCE MONITORING & OPTIMIZATION AT DUBAI

ELECTRICITY & WATER AUTHORITY’S COMBINED CYCLE POWER AND

DESALINATION PLANT IN DUBAI

Dr. Jeff Parmar & Mr. Matt Auer

General Physics, UK

Mr. Hiroyuki Ichikawa

Toshiba, Japan

Mr. Daming Yang & Mr. Shawn Whitecar, P.E.

General Physics Corporation, USA

_________________________________________________________________________

EtaPRO™, EPReporter™, EPTrendSetter™, EPAlert™, and Virtual Plant™ are trademarks of General Physics Corporation.

POWER-GEN MIDDLE EAST 2010 October 4- 6, 2010 Doha, Qatar

ABSTRACT

This paper describes a state-of-the-art real-time

performance monitoring and optimization system

installed at the Dubai Electricity and Water

Authority‟s (DEWA) Jebel Ali L1 Combined Cycle

Power Plant located in Jebel Ali in Dubai.

This plant provides gross electrical output of 796,700

kW and 70 million gallons (317,500 m3) per day of

potable water at design reference conditions of

ambient temperature of 50°C, relative humidity 34%

and ambient pressure of 1.0132bar to meet the needs

of Dubai‟s rapidly expanding economy. The Jebel Ali

L1 facility was a direct result of project agreements

for DEWA‟s Power and Water Production, which

were signed in Dubai in 2005 between Toshiba who

are the Engineering Procurement and Construction

Contractor of power plant package. The gas turbines

are supplied by General Electric and are of Frame

9FA.

The system provides real-time indication of power

and water plant Key Performance Indicators (KPI‟s),

including actual and expected values. A first

principles thermodynamic model integrating the

power and desalination processes was developed to

support both real-time and off-line “what-if” and

optimization strategies. The optimizer is fully

interactive at the desktop and allows engineers and

production managers to investigate any of over 50

different operating modes the plant is capable of

supporting. In addition to monitoring and modeling

plant processes, the system provides routine

archiving and reporting of all pertinent parameters.

The client/server software architecture provides end-

users access to the system from client/server

workstation.

By monitoring important performance parameters such

as gas turbine corrected power, HRSG and steam

turbine efficiencies, and target (or expected) steam

header pressure, plant performance can be optimized

wherever possible, and problems identified at an early

stage.

With an accurate measurement of plant performance

continuously compared with a proven benchmark,

plant personnel are able to better operate their

facilities in a competitive market, as well as ensure

that water and power production has been fully

optimized. This paper describes the design

methodology and installation process of the on-line

monitoring system, as well as pitfalls associated with

establishing achievable performance benchmarks.

Key features of the optimization system along with

the strategy employed for technology transfer to plant

staff are also discussed.

INTRODUCTION

The Jebel Ali L1 facility arose from project

agreements between DEWA and Toshiba‟s which

were signed in Dubai. The Jebel Ali L1 facility is a

nominal 800 MW combined cycle power and

desalination plant developed on a Build and Transfer

(BT) basis between a consortium of Toshiba,

Mitsubishi Corporation, Fisia Italimpianti, Alstom,

Doosan Heavy Industries and Lahmeyer

International. To maximize the profitability and

optimize water and power production, a state-of-the-

art on-line performance monitoring system was

installed to alert and advise the operating and

management staff of any deviation from the optimum

levels of performance. By monitoring important

performance parameters such as gas turbine corrected

power, HRSG and steam turbine efficiencies, and

target (or expected) condenser pressure, plant


2

performance can be optimized wherever possible, and

problems identified at an early stage.

The Jebel Ali L1 Combined Cycle Power Plant

consists of three blocks each with three GE Frame

9FA gas turbines (GTs), three Doosan Heat Recovery

Steam Generators (HRSGs) and two Toshiba steam

turbines (STs). The HRSGs are equipped with

supplementary or duct firing. There are two auxiliary

boilers which can supply steam to the steam turbines

for power production and steam for desalination

plant. The desalination plant has five distillers of sea

water fed by the steam produced from the HRSGs

and the auxiliary boilers The GTs can run in simple

cycle operation with by stacks installed at the exhaust

of each of the GTs. The gas turbines and the auxiliary

boilers are capable of firing light distillate oil which

is normally used as back up fuel in the event when

the natural gas fuel is not available or for other

operational reasons.

The Jebel Ali L1 Water Plant has been designed with

a capacity of 317,500 m3/day water produced by five

desalination units. The desalination units are of the

multi-stage flash type (MSF-type). The desalination

units are designed for a distillate production rate of

14 Million Gallons per Day (MIGD) (63,500 m3/day)

each, operating with suitable anti-scaling additive for

the make-up seawater at a top brine temperature of

108 °C and a seawater temperature range from 15 °C

to 35 °C.

During normal operation the plant is operated as a

single entity. This means that the three GTs, the three

HRSGs, the two STs, are interconnected in such a

way that “block concept” is not foreseen and any

equipment can be operated from any operating station

in the Central Control Room. The main steam

headers and the feed water headers operate as

interconnected systems.

The EPC Contractor, Toshiba in collaboration with

General Physics Corporation (GP) installed the on-

line performance and condition monitoring system,

EtaPRO™ supplied by GP. The main objectives of

installing the EtaPRO System are to readily identify

equipment performance deficiencies, cycle isolation

problems, instrumentation problems in timely manner

and above all, to optimize the generation of

electricity, water production and the steam for

cogeneration purposes. The installed system monitors

real time performance, archives process data and

calculates results, and automatically report on key

performance indicators. The installation of EtaPRO

will also be utilized to maximize the plant

profitability by alerting and advising the plant

operating and management staff of performance

improvement opportunities.

IMPROVING PLANT PERFORMANCE

The main purpose of the on-line performance and

condition monitoring system is to readily identify

equipment performance deficiencies, cycle isolation

problems or instrumentation problems on a real-time

basis. This requires the functionalities shown in

Figure 1.

Figure 1. Performance Improvement Functions

Real-time Monitoring (EtaPRO™ System). Plant

performance cannot be improved or maintained

unless it is measured and quantified in a consistent

and routine manner. This function is performed by

the EtaPRO System at Jebel Ali L1 Power Plant. The

EtaPRO System is a client/server application that

provides a comprehensive library of pre-engineered

performance calculations applicable to individual

equipment as well as the overall plant. Calculations

are customized to the requirements of the Jebel Ali‟s

specification. Process data required to support

calculations is acquired from the Toshiba‟s installed

Distributed Control System (DCS) at Jebel Ali L1.

The installed DCS system is TOSMAP-DS™. The

TOSMAP-DS utilizes the state-of- the-art

technologies which realize high-level controllability,

human friendly man-machine interface and versatile

communication with other system.

Trending (EPTrendSetter™). Trending of data is an

effective way to analyze aspects of plant behavior

and performance which cannot be perceived from the

minute-to-minute updates that occur on all the

EtaPRO screens. EtaPRO provides an intuitive but

powerful means of performing short and long-term

trending. This feature offers numerous options for

selecting and viewing historical data, including use of

data filters to identify steady-state operating periods,

high load operation, or operation near ISO or


3

reference ambient conditions. EtaPRO incorporates

the plant‟s shift schedule to allow comparison of

performance between crews if desired. Custom trends

can be saved as Trend Definitions, incorporating

specific data points, filters, scaling options, trend

colors, etc. and then readily access from the EtaPRO

Client navigation tree. Plant and equipment

performance can be trended and then saved for future

reference as Foot-Prints. This last feature is

especially useful for documenting post-overhaul

performance. As another example, steady-state gas

turbine output at base load operation within a narrow

ambient temperature range can be recovered over a

long period of time to detect output degradation. Data

can be trended by shift or crew and plotted against

time or another parameter. The ability to trend plant

and equipment performance over a long period of

time provides a significant diagnostic capability to

plant personnel. A picture of a typical trend is shown

in Figure 2. For example, if a change in gas turbine

efficiency is sudden, one might suspect mechanical

damage. Conversely, if the change occurs slowly

over time, erosion or deposits may be more likely.

Continuous real-time monitoring and trending allows

the engineer to gain greater insight into the process

than periodic special purpose performance tests.

Lastly, the ability to trend a KPI mitigates the larger

uncertainties associated with plant instrumentation

vs. special purpose test instruments.

Figure 2. EPTrendSetter

Modeling (VirtualPlant™ Software). The modern

power and desalination plant consists of several

components that operate over a wide range of

conditions. For example, the Jebel Ali L1 Plant can

operate from full power and water production (800

MW and 317,500 m3/day, respectively) down to only

enough power to meet auxiliary loads and many

combinations in between. Often new plants such as

Jebel Ali L1 are provided with a limited set of mass

and energy balances against which to compare plant

performance. Therefore, a critical part of any

monitoring system is a first–principles

thermodynamic model. This model integrates all

plant components to: provide expected levels of

equipment and plant performance, evaluate

equipment condition, validate process data, and

quantify the impact of off-design component

performance on overall plant heat rate and capacity.

GP‟s VirtualPlant thermodynamic modeling

framework meets each of these requirements at the

Jebel Ali L1 Plant.

Reporting (EPReporter™). Real-time displays are

valuable for operators and engineers when

monitoring performance or diagnosing equipment

deficiencies. However, many supervisory and

management personnel prefer to have information

pushed to them rather than having to mine or pull the

data themselves. This push vs. pull concept is

implemented using GP‟s EPReporter an automated

reporting tool that distributes MS Excel™ based

reports containing process data and KPIs to printers,

email addresses, and WEB pages. The reporting

process is automated to allow plant personnel to

focus their energies on problem resolution, not

cumbersome reporting tasks. Figure 3 shows the

EPReporter access page.

Figure 3. EPReporter

Problem Diagnosis (Diagnostic Help Charts). The

EtaPRO has the provision for providing assistance to

operators and engineers in diagnosing and resolving

“off-target” performance. Diagnostic Help Charts

provide a methodical approach for detecting the

cause(s) of low steam temperature, low gas turbine

exhaust temperature, low gas turbine compressor

efficiency etc. Each diagnostic incorporates proven


4

operating practices to help guide the operator or

engineer in detecting the root cause of a performance

deficiency.

VIRTUALPLANT OPTIMIZERS

GP‟s VirtualPlant technology, a rigorous first-

principles thermodynamic modeling framework, is

used for many purposes within the Jebel Ali L1

EtaPRO System. Plant models are executed on a real-

time basis to provide expected levels of performance

for the gas and steam turbines, heat recovery steam

generators and desalination trains. In addition, these

same models are used for both off-line and on-line

optimizers.

VirtualPlant models are created in the Cycle Builder,

which contains all the components necessary to

complete the power and water production systems.

Individual components are interconnected through

direction connections with one another. Mixer and

splitter components are used to direct flows as

necessary.

The model is solved by applying the laws of

conservation of mass and energy to each successive

component until the overall model converges within

the user-defined tolerance. Figure 4 shows the Jebel

Ali L1 model.

Real-time Targets. The VirtualPlant models are

configured to run on a continuous real-time basis for

the following four cases:

1. Base Load at Current Conditions

2. Part Load at Current Conditions

3. Base Load at Reference Conditions

4. Part Load at Reference Conditions

Case models are scheduled to run within the

VirtualPlant OPC Server, which acquires model

inputs (ambient and process data) from the EtaPRO

OPC Server. In turn, the EtaPRO Server acquires

model results continuously from the VirtualPlant

OPC Server. This two-way communication is an

effective way to share data between the two

Figure 4. VirtualPlant Cycle Builder (Jebel Ali L1 Power Station)


5

applications. Results from the four cases above are

used to present real-time targets for the EtaPRO

displays as well as to provide correction factors to

allow actual performance to be adjusted to reference

conditions for long-term trending.

On-line Optimization. The VirtualPlant model is

exercised in two ways to provide optimized

equipment settings for a current power and water

production:

1. Equipment Currently In Service.

2. Equipment Available for Service.

Models are executed in the VirtualPlant OPC Server

with results acquired by the EtaPRO System for

presentation to operators on a continuous real-time

basis.

Off-line Optimization. The VirtualPlant “What-If”

provides plant operations personnel, engineers, and

planner with a fully interactive and user-friendly tool

to perform detailed mass and energy balances of the

Jebel Ali L1 Power Plant, (see Figure 5).

The VirtualPlant allows operators to enter ambient

conditions, equipment constraints, water and power

production requirements, top brine temperature, etc.

and then determine the most effective settings for

loading the gas turbines and duct burners to achieve

the desired power and water production. Figure 6

shows the optimizer control panel.

The optimizer control panel allows end-users to

select equipment availability, choose individual

setpoints for gas turbine load, duct burner fuel

consumption, distillate production, and top brine

temperature. Operating constraints such as throttle

pressure and LP turbine exhaust flow are also set in

the control panel. Simple cycle operation as well as

gas turbine base load operation may be selected as

well. The optimizer also offers a Maximize Power

mode in which case the gas turbines and duct burners

are maximized for the ambient conditions while

meeting water production requirements.

The model is capable of giving over fifty different

modes of operations during different operating

conditions of ambient conditions. The model shows

the effect on the overall plant performance

(generation, heat rate and water production) with

different levels of supplementary or without

supplementary firing in the HRSGs. In addition,

detailed information about every component in

Figure 4 is also available.

Figure 5. VirtualPlant Off-line Optimizer

Figure 6. Off-line Optimizer Control Panel

The screen in Figure 4 depicts the full mass and

energy flows to facilitate evaluations of conceptual

changes in operating parameters as well as equipment

design and efficiency improvements if the station so

desired to carry out. The VirtualPlant “What-If” heat

balance is a first principle, rigorous engineering

model that fully integrates individual component

models to simulate the impact of any envisioned

operational or component design changes. Each

component can be rearranged or redesigned to model

and evaluate a variety of different options.

Operating parameters and templates are provided to

facilitate the users input of conceptual changes to the

existing plant design. Operating decisions such as

taking out supplementary firing in HRSGs, reducing

steam temperatures, reducing GT load, removing

desalination units from service etc. can be pre-

evaluated off-line without impacting the operation of

the actual plant with high degree of uncertainty of the

final results. Engineering evaluations, such as impact

of fouling in the desalination units, the use of duct


6

burners in the HRSGs the use of auxiliary boilers in

service can also be evaluated.

The VirtualPlant “What-If” can easily be utilized to

predict the performance of the plant at different

ambient conditions (with or without duct burners of

using gas turbines in simple cycle operation) for

dispatch purposes. The power off-taker normally

requires such information 24 hours before dispatch of

power in real time. This can drastically improve the

plant‟s ability to judge its power, efficiency and

water production capabilities and be very

competitively placed in the stacking order of

dispatch. In addition, the VirtualPlant will be used by

the station to optimize the sale of electricity, water

and steam at different supply and demand criteria.

INFRASTRUCTURE

The hardware and software infrastructures of the

Jebel Ali L1 EtaPRO System consist of standardized

components in a proven design.

Historian. The performance monitoring system is

tightly integrated with OSIsoft® technology,

allowing a direct connection to the DCS for data

acquisition, historical data retrieval, and PI tag

creation or maintenance. The system acquires all

process data (temperatures, pressures, flows, MWs,

etc.) from Jebel Ali‟s historian data base system and

the performance monitoring results are written back

to the historian system.

The performance monitoring system is installed to

allow sharing of performance information with all

levels of plant staff as well as corporate-wide, as

shown in Figure 7 below. The server is connected to

the local area network (LAN) of the Jebel Ali L1

Plant and its wide area network system (WAN). Any

desktop computer running the client application and

allowed access to the Jebel Ali L1 network has full

access to all the features of the performance

monitoring system, including viewing real-time

calculated results and retrieving historical data. The

system is protected through firewalls at strategic

locations. Due to internal security issues the remote

link to GP Support was not available during the

installation of the EtaPRO System and installation

was carried out at site.

Server. The server operates on a dedicated computer

installed by Toshiba/GP. The server acquires field

data, calculates performance, archives historical data,

and provides real-time or historical information to the

workstation "client" applications. The client software

will be used by Jebel Ali L1 users of all levels

including operators, engineers, managers and

supervisors to view or edit (with appropriate

password) the system configuration, displays, and

reports. The performance monitoring system is self-

Plant LAN

PI Server

PI InterfaceBuffer

DCS

Local Plant Clients

EtaPRO Server•EtaPRO Server•EPReporter•EP TrendSetter•PI-API•MS Office•pcAnywhere

DCS Data Highway

WANCorporate Clients

Control Room

PlantManager

Plant Engineer

GP Support (VPN)

Plant LAN

PI Server

PI InterfaceBuffer

DCS

Local Plant Clients

EtaPRO Server•EtaPRO Server•EPReporter•EP TrendSetter•PI-API•MS Office•pcAnywhere

DCS Data Highway

WANCorporate Clients

Control Room

PlantManager

Plant Engineer

GP Support (VPN)

Figure 7. Typical Hardware Arrangement

documenting. Each system is delivered with a series

of reports that describe the system configuration.

The Performance Engine provides a powerful

environment for turning process data into

Performance Information. The performance

monitoring system includes a comprehensive

Performance Calculation Library of over 500 proven

engineering calculations for assessing all types of

equipment and machinery, including gas turbines,

HRSGs, steam turbines, pumps, and desalination

units. Selecting from the extensive Performance

Calculation Library, the user can readily configure

and assess on-line performance of virtually every

major piece of plant equipment.

Client Software. The performance monitoring

software operates on Windows operating systems.

The EtaPRO Client application is used to view real-

time and historical information, and to configure and

maintain the system configuration on the server. The

workstations can update as fast as once every four

seconds, but are typically set for once a minute. Users

can monitor graphical displays, trend plant

parameters, generate reports, and modify the

configuration data (with password protection).

Automated Alerts. The EPAlert™ application

automatically sends a text message when abnormal

conditions occur within the plant. Users receive alerts

when plant status changes (unit trips, start-ups, full

load achieved, etc.). Alerts may be sent to mobile

phones, PDAs, IPAQ‟s, Blackberry®, etc. to notify

the user of plant or equipment changes.

Electronic Operations Log. The Operator Log is

designed to replace the manual log book in the

control room. A significant advantage of using the

EtaPRO Operations Log is that entries are

automatically cross-referenced with process data

trends. Figure 8 shows a typical log page.


7

Figure 8. Electronic Operations Log

INSTALLATION PROCESS

There are several key stages that have to be

systematically carried out prior to the software being

installed on the power plant‟s computers. These are

described here:

1. Collection of all design information supplied by

the Original Equipment Manufacturers (OEMs)

pertinent to the key components installed on the

power station. These include the gas turbines, the

boilers, the steam turbines, the auxiliary boiler

system, the desalination plant and the balance of

plant such as the boiler feed pumps, cooling

water pumps etc. To cover all operating

scenarios, design data is also required at part

loads and any abnormal eventualities.

2. The software model of the power plant at base

load is created using GP VirtualPlant tool. The

model incorporated with full design data is run

with different operating conditions at base load

and tuned to match the OEMs figures at off-

design conditions at base load. This involves

inserting correction factors at base load for all

ranges of operating conditions. The correction

factors include ambient temperature, ambient

pressure, ambient relative humidity, electrical

power factor, cooling water temperature, brine

water temperature etc. These correction factors

will have direct impact on the commodities

which are net revenue for the station. Jebel Ali

L1‟s net monetary revenue streams and

consequently its profitability are based on the

payments for the intake of fuel consumed and the

payment received for the generation of electrical

power and the production of desalination water.

3. Further VirtualPlant models are created to cater

for part load operations. The models created

include all gas turbines at part load operation,

different cases of gas turbine electrical output

including shut down of one or two or three gas

turbines. Cases also include total shut down of

GTs with only the auxiliary boilers and steam

turbine/s in operation for steam generation for

production of desalination water or GTs in

simple cycle operation. All models are tuned to

reflect the design data supplied for the equipment

hardware installed at Jebel Ali L1 Plant.

4. Once the design models are created in

VirtualPlant and match the design data at base

and part loads, the next task involves creating the

models to reflect the actual plant. In order to

replicate the plant „as is‟, actual test data collated

from technical documents and actual operating

conditions is inserted in the VirtualPlant models

and tuned to depict the operating conditions. The

tuning process may involve changing the design

data at this stage as the OEMs could have under

or over estimated the performance of the

hardware. This can be due to commercial,

technical and/or manufacturing/machining

reasons. If the plant was tested at different part

loads the VirtualPlant models are run to compare

the actual figures. The model may be fine tuned

to reflect the actual conditions at these loads. The

GPC‟s VirtualPlant software is also capable of

calculating the „What-If‟ scenarios for this plant.

5. In parallel with the above tasks, the plant‟s

existing hardware and the software DCS is

thoroughly checked for its compatibility with the

Toshiba/GPC‟s hardware and software system

prior to linking it together. The link continues to

the end users and can be used the Operators,

Engineers, Managers, Traders, Planners,

Dispatchers etc. This meticulous job involves

checking the existing station‟s historian and data

collection system. Each tag of the data with its

unique numbering system that is connected to

the DCS Software is checked for its integrity and

connectivity. The tags are used to display direct

readings in engineering units or the engineering

units are used for performance calculations. The

mathematical formula and/or equations are

tailored to meet specific plant criteria and display

screens in the EtaPRO system.


8

REAL-TIME PERFORMANCE MODULES

The performance monitoring system provides

engineers and supervisors with a convenient and

efficient means of tracking plant performance. Since

the Jebel Ali L1 Combined Cycle Plant and

desalination plant performance is subject to wide

variation with ambient conditions, component and

overall plant capacity and heat rate must be corrected

to current conditions on a minute-to-minute basis.

The following displays are typical of the Jebel Ali L1

facility, as well as other combined cycle plants

equipment with EtaPRO.

Operator Controllable Parameters. Industry

experience has shown that power plant operators play

a key role in any heat rate improvement program.

The Operator Controllable Parameters, as shown in

Figure 8, provide operators with the information

needed to operate at peak efficiency. A tabular listing

of key controllable parameters such as gas turbine

inlet air filter pressure differential, gas turbine inlet

temperature (for inlet cooling systems), condenser

pressure, cooling water temperature, and compressor

section efficiency are displayed, along with

appropriate “target” values. The performance

monitoring system displays the costs associated with

“off-target” operation, thereby allowing operators to

trade-off the savings of one parameter against another

to achieve optimal performance. A real-time strip

chart useful for detecting drifting performance shows

the deviation of any parameter including plant heat

rate from its target for the past hour. For the engineer,

the performance monitoring system provides the

unique capability to instantly substitute the “design”

values (one mouse click) for “target” values to

determine the cost of operating with deteriorated

equipment (real-time and historical data).

Gas Turbine. As shown in Figure 10, key

performance parameters such as heat rate, capacity,

combustion air flow and exhaust temperature are

corrected to “standard day” conditions to allow direct

comparison with design specifications or acceptance

test performance. This comparison provides

engineers with the information necessary to detect

“off-spec” performance. This module also computes

compressor efficiency and provides operators with

key operating “targets” for current loading and

ambient conditions.

The performance monitoring system monitors actual

gas turbine performance (heat rate, capacity, natural

gas fuel flow, exhaust flow, expander efficiency,

compressor efficiency, etc.) and compares actual

performance to expected performance at current

ambient (temperature, pressure and humidity) and

Figure 9. Operator Controllable Parameters

Figure 10. Gas Turbine Performance

operating conditions (part load, NOx control, etc.). In

addition to expected performance at current

conditions, the performance monitoring system also

has the capability to correct observed performance to

“Standard Reference” conditions.

Heat Recovery Steam Generator. Safely maintaining

optimum plant efficiency requires close attention by

the operating staff for proper coordination of gas

turbine and HRSG operation. The performance

monitoring system provides operators and engineers

with a profile of actual and expected performance

including HRSG efficiency, expected steam

generation and outlet temperatures for each section,

and heat transfer section effectiveness as presented in

Figure 11.

The performance monitoring system monitors actual

HRSG performance (ASME Loss Method efficiency,

input/output efficiency, effectiveness, and pinch

point) and compares this performance to expected

performance at current ambient conditions and

operating conditions. The performance monitoring

system uses a rigorous heat transfer model to predict

expected performance at part load and off-design

conditions. Performance indices of the HRSG, such


9

Figure 11. HRSG Performance

as heat transfer rate, effectiveness, and pinch point

analysis is provided for each HRSG section.

Steam Turbine. The performance monitoring system

calculates actual steam turbine performance (section

enthalpy-drop efficiencies, stage flow factors,

corrected stage pressures, turbine cycle heat rate, and

generator capacity) and compares actual performance

to expected performance at current ambient

conditions and operating conditions as displayed in

Figure 12. The system also has the capability of

calculating individual turbine section power outputs,

low-pressure turbine efficiency by energy balance,

and throttle flow corrected for initial conditions.

Figure 12. Steam Turbine Performance

Desalination Unit Performance. Perhaps more than

any other operating parameter, the performance ratio

of the desalination has the most significant impact on

turbine and the bottoming cycle heat rate. The

desalination performance determines how much

steam is extracted depending on the top and bottom

brine temperature, circulating water flow, tube

cleanliness, heat loading, and the sea water

temperature. Actual performance is compared to

expected values by using a detailed desalination

model to predict the water production under varying

operating conditions as shown in Figure 13.

Figure 13. Desalination Unit Performance

The performance monitoring system uses a detailed

desalination model to estimate design and target

performance for current operating and ambient

conditions such as heat load and circulating water

inlet temperature. Design performance is predicted

using the design parameters, while “target”

performance accounts for fouled desalination unit.

This approach allows the engineer to determine the

cost of operating with fouled unit over the long term.

Target parameters represent achievable performance

for the operating staff based on current equipment

condition.

On-line Optimizer. This application helps operators

identify the most efficient way of running the plant

by looking at the current operating conditions and

comparing that with the equipment that is already in

service and also with the equipment that would be

available. The screen depicts the main component of

the power plant and gives instantaneous picture of the

optimization of the plant in service and plant that is

not running but is available. The On-Line Optimizer

screen is shown in Figure 14.

TECHNOLOGY & OWNERSHIP TRANSFER

Key to achieving improved operation is a unique

combination of state-of-the-art software and

technology transfer through training and mentoring

for the plant operations team. This combination

provided the information needed for improved

information as well as a knowledgeable workforce

that understood how to use the "new" information

and tools to improve operations and business

processes.

Open System. The performance monitoring system is

a full-capability “open system” with extensive

features and capabilities to provide value over the life

of the system. This means that the Jebel Ali L1

Engineering and Operations personnel can expand

the breadth and depth of the performance monitoring

system without additional costs from the vendor. This

transfer is facilitated by use of an extensive library of


10

calculation and equipment design templates, and

workforce training.

Figure 14. On-Line Optimzer

Training & Documentation. The importance of

training and documentation is emphasized to assure

performance monitoring system “transfer of

ownership” as well as acceptance and use of the

performance monitoring system by operating

personnel.

System Administrator Training is a hands-on, in-

depth training session where the Jebel Ali L1

Technical Staff becomes familiar with the

performance monitoring system architecture from a

user-configuration standpoint. The training focuses

on database configuration; Virtual Plant

configuration; owner customizable features such as

developing new screens; scheduling and configuring

automated reports; modifying the data base;

exporting data files to spreadsheets; changing target

values; and troubleshooting tips and procedures. The

documentation describes the overall operation and

hardware configuration details.

User Training is a hands-on program that covers the

use of the system‟s features and capabilities. The

documentation describes the screen displays and how

to access different system capabilities. The User

Training and documentation are presented in English

to assure that all plant personnel accept and use the

performance monitoring system to increase

efficiency, reliability and capacity.

INITIAL RESULTS

Initial study shows that the Jebel Ali L1 Plant

presently has some areas identified for potential

savings. These areas include optimization of

electricity sales with desalination water and

cogeneration loads with HRSG with and without

supplementary firing. Additional plant runtime at

base load conditions is required to establish

performance baselines and check for other potential

savings. Engineering analyses continue with the

results presently being produced from the online

performance monitoring system.

The performance monitoring system will be used for

the following evaluation studies:

Gas turbines operating at different loads and the

impact on power, efficiency, desalination water

production and cogeneration steam supply

Use of duct burners when gas turbines are out of

service

Optimization of evaporative coolers

Optimization of the balance of plant including

the desalination system

Final results of these evaluation studies will be

presented later.

REFERENCES

1. DesJardins & Novelli, Global Generating Asset

Management Using Real-time Performance

Monitoring and Reporting, PowerGen

International 2002, Orlando, FL, USA.

2. DesJardins, Daycock & Fennell, Generation

Cost Forecasting Using On-line Thermodynamic

Models, Electric Power 2004, Baltimore, MD,

USA.

3. DesJardins, Daycock & Kram, Forecasting

Asset Performance Using Real-time

Thermodynamic Models, PowerGen International

2004, Orlando, FL, USA.

4. DesJardins, Parmar, Yang & Zafar, Real-time

Performance Monitoring & Optimization at Ras

Laffan Power Company’s Combined Cycle

Power and Desalination Plant in Qatar,

PowerGen Middle East 2007, Manama, Bahrain.

ACKNOWLEDGEMENT

GP is very grateful to all Jebel Ali Operation Staff for

all their cooperation given during the successful

handover of the EtaPRO System to DEWA. GP wish

to thank all Toshiba staff who assisted in the

installation of the EtaPRO System at Jebel Ali L1

Power Station.

on-line performance monitoring - gpilearn connect resources/real time...art on-line performance...

Documents