basis of design edit

PROJECT TITLE

GEOTHERMAL POWERPLANT SEPARATOR, SCRUBBER AND BRINE

DISPOSAL SYSTEM

BASIS OF DESIGN

PREPARED BY CHECKED BY APPROVED BY DOCUMENT NUMBER

SFF RAT PIC-E-NTV-627-003

DATE REVISION PAGE

2-2-2014 2-3-14 A 1 of 58

2 of 58BASIS OF DESIGN Sheet

GEOTHERMAL POWERPLANT SEPARATOR, SCRUBBER AND

BRINE DISPOSAL SYSTEM

Rev. No. A

Doc. No. PIC-E-NTV-627-003

TABLE OF CONTENTS

SECTION ITEM PAGE NO.

Abbreviations, Definitions, Standards, References 4-8

1. INSTRUMENTATION

1.0 Introduction 9

1.1

Site Description 9

1.2

Environmental Condition 10

1.3

Measurement Units 10

2.0 Instrumentation System Requirements 10

2.1

Process Equipment 11

2.1.1 Separator 11

2.1.2 Scrubber 11

2.1.3 Flash Tank 12

2.1.4 Level Drum 12

2.1.5 Pump Motor 12-13

2.2

Field Instruments 13

2.2.1 Level 13-14

2.2.2 Pressure 15-16

2.2.3 Flow 16-17

2.2.4 Others 18-21




Rev. No. A


2.3

Control Room 21

2.3.1 Facility 21

2.3.2 Environment and Location 21

2.4

Junction Boxes 22

3.0 Instrument Material Selection 22-23

4.0 Supply System 23

4.1

Electrical 23

4.2

Pneumatic 23-24

5.0 Equipment Protection 24-26

6.0 Earthing System 27

7.0 Cable Requirements 27

7.1

Cable Types 28

7.1.1 Instrument Cable 28

7.1.2 System Cable 28

7.1.3 Signal Cable 29

7.1.4 Power Cable 29

7.1.5 Special Cable 29

7.1.6 Junction boxes Cable 29

7.2

Cable Identification 30

7.3

Cable Shielding 30




Rev. No. A


7.4

Cable Marking 31

7.5

Cable Runs 31

7.6

Cable Installation 32

7.7

Cable Termination 32-33

2. CONTROL

1.0 Introduction 34

2.0 Operation System 34-35

3.0 Safeguarding System 35

4.0 Equipment Locations 35

4.1

Methods 36

4.2

Elevation 36

4.3

Operating Convenience 36-37

4.4

Plant Equipment Layout 37

5.0 Basic Control and Monitoring 37-40

6.0 DCS and PLC Requirements 40-43

7.0 System Architecture 43

7.1

Narrative 44-45

7.2

Drawing 45




Rev. No. A


3. SAFETY

1.0 Introduction 46-47

2.0 Safety System (Fail Action) 47-48

2.1

System Architecture (DeltaV SIS) 48-49

3.0 Emergency Shutdown System 49-50

4.0 Fire Detection System 50-51

5.0 Gas Detection System 51-52

6.0 Audible and Visual Alarms 53

4. NAMING CONVENTION

1.0 Introduction 54

2.0 Naming Convention 54-58

DEFINITION

Engineering Procurement Construction Company or EPC

It is the contractor that will make the detailed engineering design and work of the

project. In this case the Process Instrumentation Company will provide for it.

ABBREVIATIONS

UPS Uninterruptible Power Supply

VIM Virtual I/O Module

Trigon, 02/28/15,

Kung may maidadagdag pa kayo.pa-add na lang thanks

Trigon, 02/28/15,

Pa-double check. Pakitignan maigi kung lahat ng abbreviations dito sa basis na-identify dito sa list.thanks




Rev. No. A


PVC Polyvinyl Chloride

ESD Emergency Shut Down

IP Ingress Protection

HMI Human Machine Interface

NPT National Pipe Thread

AWG American Wire Gauge

AC Alternating Current

DC Direct Current

SS Stainless Steel

CS Carbon Steel

DCS Distributed Control System

PLC Programmable Logic Controller

VDU Visual Display Unit

MCC Motor Control Cabinet

SIS Safety Instrumented System

HART Highway Addressable Remote Transducer

AI Analog Input

AO Analog Output

DI Digital Input

DO Digital Output




Rev. No. A


FF Foundation Fieldbus

REFERENCES

The different standards reflected as references should be used upon the completion

of the project. The dated references shall be necessarily applied. If there are any

changes regarding on the dated references, the client and the contractor shall have an

agreement on whether they will apply it or not. The newest standards and codes shall

be used for the undated references.

International Electro technical Commission (IEC)

IEC 60331 Tests for Electric Cables under Fire Conditions

IEC 61131 Programmable Logic Controllers

Trigon, 02/28/15,

Since, hindi na kasama yung sa field instrumens, mababwasan ito. Pakibase sa content nito yung mga reference na ginamit.thanks




Rev. No. A


IEC 61158 Industrial communication networks – Fieldbus specifications

IEC 61508 Functional safety of electrical/electronic/programmable

electronic safety-related systems

IEC 61511 Functional safety – safety instrumented systems for the

process industry sector

IP RATINGS (Ingress Protection)

IP 65 Totally protected against dust ingress, protected against low

pressure water jets from any direction.

IP 55 Limited protection against dust ingress, protected against

low pressure water jets from any direction.

IP 42 Protected against solid objects over 1.0mm e.g. wires,

protected against falling drops of water, if the case is

disposed up to 15 from vertical.

International Society of Automation (ISA)

ISA 5.1 Instrumentation Symbols and Identification

ISA 5.4 Instrument Loop Diagrams

ISA 5.7 Process and Instrumentation Diagrams

ISA 7.0.01 Quality Standards for Instrument Air

ISA 71 Environmental Conditions for Process Measurement and

Control

ISA 75.01 Control Valve Sizing Equations




Rev. No. A


ISA75.04, Control Valve Stability

ISA75.07, Control Valve Noise Measurement and Prediction

ISA75.08, Control Valve Face-to-Face Dimensions

ISA77.22, Power Plant Automation

ISA/ANSI –S 84.01 Application of Safety Instrumented Systems for the Process

Industry

National Electrical Manufacturers Association (NEMA)

NEMA 250 Enclosures for Electrical Equipment (1000 Volts maximum)

National Fire Protection Association (NFPA)

NFPA 70 National Electrical Codes

NFPA 1 Fire Protection Code

NFPA 67 Guides on Explosion Protection for Gaseous Mixtures in

Pipe Systems

NFPA 59A Standard for the Production, Storage, and Handling of

Liquefied Natural Gas (LNG)

NFPA 72 National Fire Alarms and Signaling Code

American Petroleum Institute (API)

API RP 505 Recommended Practice for Classification of Locations for

Electrical Installation at Petroleum Facilities Classified as

Class I, Zone 0, Zone 1 and Zone 2 (2002).

API RP 500 Recommended Practice for Classification of Locations for

electrical Installation at Petroleum Facilities Classified as

Class I, Division 1 and Division 2.




Rev. No. A


Indian Standard (IS)

IS 5831 PVC insulation

A. INSTRUMENTATION

1. INTRODUCTION

The basis of design for instrumentation shall discuss the considerations under

the scope of plant process instrument general requirement e.g. type of materials,

operating ranges, standards for equipment protection and even overview of the

geographic location of the process field. The pre-determined process conditions

such as exposure to corrosive and toxic gases, process ambient temperature and

other factors that may degrade the functionality of the instrument installed shall be

the foundation in selecting the right material to be used. The purchase of the right

equipment shall determine the efficiency of the instrument and the length of its

service.

The basis of design for instrumentation shall state the plant process instrument

general requirement e.g. type of materials, operating ranges, type of connections,

standards for equipment protection and even overview of the geographic location of

the process field. Pre-determined process conditions such as exposure to corrosive




Rev. No. A


and toxic gases, process ambient temperature and other factors that may degrade

the functionality of the instrument installed shall be the foundation and basis for the

purchase of materials to be used. The basis for instrumentation shall determine

which equipment is suitable for the given application and the length of its service.

1.1 SITE DESCRIPTION

The Tiwi field is located about 300-km southeast of Manila in the Albay

Province. The Tiwi geothermal field will be located on the northeast flank of Mt.

Malinao, an extinct Quaternary stratovolcano in the East Philippine Volcanic Arc.

This arc is a belt of upper –Miocene to Recent calc-alkaline volcanoes

associated with subduction along the Philippine Trench. Mt. Malinao is composed

dominantly of <0.5 million year-old andesitic lavas and lesser pyroclastic rocks.

Tiwi Geothermal Power Plant coordinates are 13°27'54" N and 123°38'55"

E in DMS (Degrees Minutes and Seconds) or 13.4649487555258 latitude and

123.648541284874 longitudes (in decimal degrees). It has an elevation of ~45

meters.

Trigon, 02/28/15,

Include picture of location area if available. Thanks




Rev. No. A


©googlemaps.com

1.2 ENVIRONMENTAL CONDITION

The geothermal plant geographical location has a humid subtropical

climate with 1, 850 – 2, 300 mm annual rain fall. The ambient temperature is

ranging from 75.38 °F to 82.58 °F with relative humidity at 83-96% and 3.6 km/h

North wind speed.

1.3 MEASUREMENT UNITS

2. INSTRUMENTATION REQUIREMENTS

Liquid Flow Rate = GPMgpm

Gases Flow Rate = Nm3/h

Steam Flow Rate = kg/hr

Temperature = °C0F

Pressure = lb/in2

Vibration = dB

Level Relative = 0-100 %

Level Absolute =iIn. or

mm

Gage Pressure = psig

Trigon, 02/28/15,

Please update this based on the process. You can refer to gen specs/datasheet.thanks




Rev. No. A


This part contains the basic requirements of different instruments, and equipment

needed in the process of separator, scrubber and brine disposal system.

2.1 PROCESS EQUIPMENT

The selection of the process equipment shall be based on conditions and

the desired standards for which it is expected to comply. The main goal for

detailing these conditions is to be efficient in terms of equipment reliability.

2.1.1 SEPARATOR

The type of separator to be used is the Upgraded CE Natco. It

shall be constructed with 316L stainless steel to comply with the tank

design temperature and pressure which is 400 °F and 200 psi. The

diameter of the tank shall be 2743 mm and 7620 mm height. to

accommodate 600-800 kph flow rate capacity. Its operating parameters

shall range from130 – 180 psig at water level. Its two-phase entry will be

tangential. The height of steam outlet to inlet is recommended to be

positive with acceptable pressure drop of 7-10 psi.

Principle of Operation

The two phase fluid enters the separator through the two phase inlet

nozzle.

The separation process commences by utilizing the difference in

density of the liquid and the vapor phases of the two phase fluid.

Trigon, 02/28/15,

For revision and please include the ff.:*concept*principle of operation*construction (please include picture)*major separation process*impurities present with percentages*steam characteristics*design pressure and temp. and dimensionNote: Please refer to powerpoint presentation from GPC or research




Rev. No. A


It operates by using the centrifugal force of the spinning steam and

brine mixture inside the separator to force the brine to the wall of the

vessel.

The brine then drops to the bottom of the vessel exiting to the brine

outlet while the lighter steam and gas exits through a pipe extending

up the inside of the vessel.

The 2-phase phase fluid usually contains carryovers and impurities

present in the steam such as silica and chloride and non-condensable gas

(NCG). The carryovers can be removed by the centrifugal action possible

with the separator’s design while silica and chloride and non-condensable

gases are found to be difficult to remove, proper selection of materials that

can withstand their effects must be put into consideration.

2.1.2 SCRUBBER

The scrubber purifies the steam by separating the pure steam from

other impurities that the separator failed to remove. This is done to meet

the minimum requirements of the power plant. TheThe plant steam quality

requirements are as follows:

Silica Maximum of 1.0 ppm

Chloride Maximum of 1.0 ppm

Steam Quality Minimum of 99.75%

Non-Condensable gases Should be between 1.0 to 3.0 ppm

Trigon, 02/28/15,

Please do not erase this part.

Trigon, 02/28/15,

For revision and please include the ff.:*concept*principle of operation*construction/design (please include picture)*design pressure and temp. and dimensionNote: Please refer to powerpoint presentation from GPC or research




Rev. No. A


The steam quality can be achieved by using Porta-test scrubber. This high

pressure scrubber shall have an inner diameter of 3657 mm with 1066.8 mm

height. It s shall be built to operate atdesign temperature and pressure will be

405⁰F deg. Fahrenheit temperature and pressureand of 200 pPsig.

Principle of Operation

Primary separation takes place as gas enters through a tangential nozzle,

creating centrifugal force and forcing the heavier liquid particles to the vessel

wall. From there, the liquids drain to the stilled chamber in the bottom of the

vessel.

Secondary separation occurs as the spinning gas converges at the center

of the separator and enters the vortex finder tube. Inside the vortex finder tube,

the gas spins at a higher velocity and forces any remaining entrained liquid to the

tube wall. This liquid is swept upward toward the gas outlet. Prior to exiting the

vessel, the liquid and a 10% side stream of gas are drawn through a small gap in

the vortex finder tube and returned to the primary separation section. A low

pressure area in the primary separation section created by the spinning gas

provides the necessary differential pressure driving force.

2.1.3 FLASH TANK

Flash tank is where a pressurized high-temperature water enters,

as water enters the flash tank a sudden decrease in the pressure causes

the liquid to vaporize into steam. This vapor is released into the

atmospheresteam and the cois thendensate is disposed to the sumpuse

for power generation. Its material construction shall be the made with

carbon steel same with the scrubber since the pressure andwith design

temperature and pressure of experienced by the vessels is measured to

Trigon, 03/01/15,

For revision. Please make it more detailed. Include the ff: *concept*principle of operation*construction/design (please include picture)*design pressure and temp. and dimensionNote: Please refer to powerpoint presentation from GPC or research




Rev. No. A


be around 200 psi at 400 °F and 200 psi. The flash tank parts are brine

inlet and outlet and vapor outlet for vapor venting, and manhole for

maintenance and inspection.The vessel must be made of corrosion

resistant materials.

2.1.4 LEVEL DRUM

Level drum is ashall hold condensate holding vessel acquired from

scrubber which is expected to hold liquid with high pressure and

temperature condensate and. low pressure vapors. The level drum

dimension shall be: 406.4mm inner diameter and height of 1524 mm

constructed with materials carbon steel designed with that are capable to

operate at 200 psi and 400°F.

2.1.5 Seal Water Tank

Seal water tank stores fresh water supply that is to be fed into the

brine pumps. The tank shall be constructed with carbon steel material and

shall be designed with low temperature and pressure.

2.1.65 PUMP MOTOR

The pump that will be used for saturate disposal must be able to

operate at 405°F temperature with low pressure head required. The

centrifugal pump used to drive brines and other fluids in geothermal

Trigon, 03/01/15,

Make it more detailed. Please include the ff:*type of pump*operation*design/construction

Trigon, 03/01/15,

For revision. Please make it more detailed. Include the ff: *concept*principle of operation*construction/design (please include picture)*design pressure and temp. and dimensionNote: Please refer to powerpoint presentation from GPC or research




Rev. No. A


process shall adopt ISO 5199:2002 Technical specifications for centrifugal

pumps— Class II. Its casing is preferred to be made up of carbon steel

with hard iron impeller for erosion-corrosion and abrasion resistance. It’s

working parts including float, valves and mechanical linkage shall be 316L

stainless steel. Zinc anodes and epoxy paintings for protection shall be

considered. The pPump motor will be driven by 3-phase with YB-type –

explosion proof motor squirrel-cage induction motor.

2.1.6 PIPELINES

Pipelines shall be routed as short as possible to minimize turns and

incline. The most important aspect in its design is usually to keep the route

monotonic and the incline slight in order to minimize pressure drop and

slug flow conditions in the pipeline. Pipe insulation shall be designed to

lessen pressure drop during steam transmission.

For the separator and scrubber steam pipelines, stainless steel

shall be used where the properties of steel e.g. corrosion resistant, high

tolerance to pressure and temperature can increase productivity. The

pipeline for brine disposal shall be made up of carbon steel for a thicker

material selection.

The pipelines shall be according to its application. For steam

pipelines, the material construction shall be made up of 316L stainless

steel with design pressure and temperature of 200 psi and 400°F. As well

as the pipelines for brines with minimum material requirement of carbon

steel construction.

2.2 FIELD INSTRUMENTS

Trigon, 03/01/15,

*type of pipeline*material (pakiexplain na rin kung bakit yun ung material.Please include this: yung upper part ng scrubber at separator, stainless steel yung pipe kapag naman sa lower part ng separator, scrubber at yung buong brine,carbon steel naman ung piping




Rev. No. A


All field instruments must withstand the extreme process for which they

are installed for. The highest range of pressure involved is at 200 psi while

temperature is expected to be at around 405 °F. The type of material

construction must protect the mechanical and electrical components of an

instrument to give accurate results and prolong its service.

2.2.1 LEVEL

The saturated fluid and condensate level shall be controlled using

equipment that determines the said process variable. This equipment

follows the standards that satisfy the requirement for which it is intended

to be use.

LEVEL TRANSMITTERS

Level transmitters are used to measure and indicate level in the

process. It shall have an electrical output signal of 4-20mA in order to

transmit signal to the controllers and other instruments. Transmitters with

flush flange connected both sides are used for direct mounting, capillary or

process connections.

The pipe size and fittings for the level installation shall be in inch

and threads in NPT. The transmitter shall use 1199 Remote Seal to form a

Tuned-System Assembly that improves performance and reduced cost.

Other installed components shall be 316 SST conduit plug. For process

connections, ½” NPT is used. The enclosure rating shall be IP66 for

ingress protection of the transmitter.




Rev. No. A


LEVEL GAUGES

Level Gauges are installed so that the liquid level in the transparent

sight tube is same as the liquid inside the tank. Level gauge shall

compose of the following parts: armored shield with two flanges, sight

tubing and two self-sealing Super-Seal inserts. Only the PTFE Teflon

Super-seal inserts and the borosilicate sight tubing are exposed to the

process fluids. The standard shields shall be epoxy-coated carbon steel.

For installation, the support brackets should be longer than 10 ft. or

heavier than 75 lbs. and the alignment should be in vertical position.

LEVEL SWITCHES

Level Switches sense high or low liquid levels. These shall operate

in safety shutdown systems and use a displacer-style sensor located in an

external cage. The displacer cage with 4” diameter shall have two NPT

pipe plugs for easy relocation. For electrical connections, the external size

shall be ½ NPT. The standard construction material of level switch shall

comply the metallurgical requirements of NACE MR0175-200.

2.2.2 PRESSURE

Pressure is measured to determine its effect to the process and for

the equipment safety monitoring. Turbines requires specific amount of




Rev. No. A


pressure to be applied, by measurements acquired from process

instruments, the operators can determine whether the amount of pressure

can drive the turbines or not.

DIFFERENTIAL PRESSURE TRANSMITTER

The differential pressure transmitter shall consist of a mechanical

measuring system with elastic pressure element of magnetic-field-

dependent sensor with amplifier and case. The resulting differential

voltage from the coupled sensor is amplified to current signals. It shall

have a standard output signal of 4-20mA. The maximum working pressure

may be 100 up to 250 psig.

The pressure connections shall be 2xG ½ female. Wetted parts and

case shall be made of stainless steel and NiCrCo alloy. It shall meet the

standard for the ingress protection of the transmitter which is IP65.

PRESSURE TRANSMITTER

Pressure transmitters shall be in-line to the process pipeline and

shall provide gage pressure measurement and indication. It shall have an

output signal of 4-20mA based on HART protocol. A change in signal is

directly proportional to the pressure measured by the diaphragm sensor.

The pressure range shall be -14.7 to 300psi. The maximum measured

error shall have a tolerance of +/-0.15% of span. Isolating diaphragm and

wetted material parts shall be 316L SST and Alloy C-276. ½-14 NPT

female may use for the process connection.

PRESSURE INDICATORS




Rev. No. A


Pressure indicators shall be used for local indication. The

measuring element shall be diaphragm seal to protect from slurry fluids.

Using this type of indicator, the size of flanged shall be 1 ½”. The range

shall read approximately 1/3 to 2/3 of full scale and its maximum error

shall not exceed 1% of the span. The window material shall be of Shatter-

proof glass.

Its process connection shall be bottom entry type of SS 316 and ½”

NPT. The indicators shall capable of withstanding 130% of maximum

range without affecting its accuracy. The enclosure shall be weather proof

to NEMA 4X/IP66.

2.2.3 FLOW

An instrument for flow determination is designed to compensate the

information that the level controllers cannot acquire from level instruments.

The accuracy of these instruments can be preserved by using appropriate

instrument material construction.

ORIFICE PLATE FLOW METER

Orifice flowmeter shall be comprise of a concentric square edged

orifice plate designed for flange tap and capable of withstanding

differential pressure equal to full line pressure without zero or calibration

change. Flange taps shall be of size ½” NPT.




Rev. No. A


It shall meet the requirements of BS 1042 and ISO 5167 in all

aspects in measuring flowrate. For two wires, the output signal shall be 4-

20mA. The wetted materials such as orifice assembly, stem, and manifold

shall be made of 316L stainless steel.

PITOT TUBE FLOW METER

The Pitot tube flow meter shall have cross-sectional T shape that

allows flow separation at a fixed point. It shall be comprised of high and

low pressure plenums and shall have the ability to accommodate RTD

integral to the sensor. Also, the sensor shape shall promote less turbulent

zones on the backside of the sensor.

These flowmeters shall be made in 316L stainless steel and

hastelloy 276, and can withstand in the maximum pressure and

temperature of 200 psig at 405 °F. The mounting material shall be

constructed from same material as process pipe. Threaded and welded

opposite side support assemblies shall be applicable.

2.2.4 OTHERS

This includes the other general instruments involved in the

separator, scrubber and brine disposal system such as valves, actuators,

etc. which are not classify in the four process variable measurement.

CONVERTERS




Rev. No. A


Converters are used to change an analog signal (4-20mA) to a

proportional linear pneumatic output (3-15psig) or vice versa. For split

ranging, it shall be recalibrated to provide higher output signals.

The minimum supply pressure shall be 3 to 15 psig. For safety

purposes, it should be enclosed when installed in outdoor environment

with an enclosure rating of IEC standards IP65.

HAND SWITCHES

Hand Switches are electrical switches actuated by hand motion.

The switches shall have three position changeover sequence for open, off

and auto control. The position indexing options may be 900 or 450. The

current rating should be 6A with a rated voltage of 690V. Silver/Nickel

shall be the contact material. For finger terminal protection, IP2X standard

shall be used.

HAND CONTROLLERS

Hand Controllers shall be protected against transient voltages and

reverse polarity. The supply voltage and current may be 24V AC/DC at

250mA.The temperature operating condition may be 32°F to 122 °F.

These controllers must be installed inside a NEMA 3 (IEC IP54), or

better enclosure and mount to standard 35mm DIN rail track.

ACTUATORS

The cylinder type actuators shall be used in the whole process.

These actuators shall be direct acting that provides fail-to-open for




Rev. No. A


normally close valves. The standard pressure range shall be 3-15psig. Its

maximum operating pressure may be up to 150psig. The connection shall

be in NPT.

Cylinder actuators shall be supplied with a compound link and lever

arrangement designed to minimize water hammer by providing

characterized opening and closing. Each unit shall comply AWWA C540-

93 Standard for Power Actuating Devices. All wetted parts of the cylinder

shall be nonmetallic, except the cylinder rod which shall be chromium

plated stainless steel. The rod seals shall be of the nonadjustable, wear

compensating type.

CONTROL VALVES

The control valves body shall be made of high temperature cast

steel. The temperature range should be -320 to 800°F and its pressure

rating shall comply the ANSI Class 125-300. These control valves shall

consist of a body with trim, bonnet and pneumatic actuator with metal

bellows or insulating extension. Also, these valves shall have fail-safe

action upon loss of air supply. All control valves scale shall be calibrated

from 0-100% and may installed vertically and horizontally.

SOLENOID VALVE

The solenoid pilot-operated diaphragm valve is suitable for

controlling air pressure. For general atmospheres, the material shall be

brass body. It can be used to pilot large actuators for quick closing of

control valves. It shall be resilient seating for tight shutoff and can be




Rev. No. A


mounted in any position. For pipe sizes from 3/8”-1” NPT, with pressure

ranges from 10psi to 250 psi.

PRESSURE SAFETY VALVE

Pressure safety valve with rupture disk housing shall be made of

316 SS base on IP 65, IP 66 IEC 61508. The size of the rupture disk

device is generally the same as the PRV inlet connection. It shall be loop

powered with the 4-20mA transmitter signal to the controller. Proper

cabling type and diameter shall be used for input power as well as for the

output signal. Shielded stranded copper shall be. It shall have a size

between 10 to 14 AWG.

2.3 CONTROL ROOM

The control room shall provide shelter for operators and workstations and

must be constructed with materials that do not easily corrode. It must be

enclosed to avoid exposure from hydrogen sulfide and other air contaminants

that may deteriorate control room facilities. Air filters can be installed to provide

total protection against air impurities.

2.3.1 FACILITY

The centralized control room shall consist of workstations, alarm

consoles, HMI- interface, ESD switches/pushbuttons and visual and

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Make it more detailed.

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Delete this part




Rev. No. A


audible alarms. Auxiliary power source such as gGenerators and

uninterruptible power supply will be considered in case of power failure

occurs. Air-conditioning units shall be installed to protect control facilities

from overheating and for operator comfort. Fire extinguisher must also be

available.

Marshalling cabinets will be located at an area opposite to the

operator consoles or workstations, as well as the system cabinets. The

preferred entry of wirings from the field to its designated cabinets is top

entry since the central control room will be designed to be at ground level

with certain elevation..

2.3.2 ENVIRONMENT AND LOCATION

The central cControl rooms will be located 1400700 m at most from

the process field to avoid being exposed from the heat released by the

steam and hydrogen sulfide which can cause severe corrosion. The

ambient temperature inside the control room must be maintained at 18

deg. Celsius with 50% relative humidity and 0.1ms-1 maximum air speed.

2.4 JUNCTION BOXES

Junction boxes provide termination of process instruments cables

because instrument wire cannot send signals at a further receiver. These boxes

are within process areas where nearby instruments are found and therefore

Trigon, 03/01/15,

Please ask junie or research for further details.

Trigon, 03/01/15,

Please include the environment conditons like ambient temp, humidity, etc.




Rev. No. A


exposed to hazardous and corrosive environment. The minimum standards for

junction boxes will be based on NEMA enclosure type which covers corrosion

resistance and ability to protect from rain and submersion or the NEMA 4x types.

The enclosure will be made up of 316L stainless steel with 1.5 mm thickness.

The cables that will be inserted into the junction box will be protected by epoxy

stainless steel cable glands to prevent entry of corrosive gases inside the

junction box.

All the wires of field instruments are terminated to the junction boxes. An

area in the fieldn area may consist of different junction boxes depending on its

capacitysignal type. Each instrument has input and output signals which can be

classified either Analog or Digital.Instruments with analog signals will be

terminated in analog junction boxes, while cables with digital signals are

terminated in digital junction boxes.

These boxes shall be elevated with minimum elevation of 1.5 feet,

depending on its size and capacity.

There are cases considering the assigned I/O signal type to the field instruments. If the

accessories are separated from its main field device, then the I/O signal type is

assigned to the accessories instead to the main field device. For example, if the

transducer (I/P Converter) is separated to the control valve, then the Analog Output

signal from the control valve is assigned to the transducer (I/P Converter).

3.0 INSTRUMENT MATERIAL SELECTION

Instrument material selection must be according to its application. In geothermal

process where critical and extreme conditions are involved, material selection must

always consider the process temperature and pressure to prevent degradation of the

Trigon, 03/01/15,

Yung mga list ng manufacturers paki-include. Then hindi tayo pumipili ng material na made in china




Rev. No. A


instrument’s accuracy. Instruments that havewhich involve direct contact with

superheated fluid or steam must have an operating range prior to actual measurements

with additional tolerance. for fluids at 400 °F and can handle pressure at 200 Psi. Also,

materials should be corrosion resistiveresistant to corrosion since the underground

steam releases hydrogen sulfide which reacts fast with metals with no corrosion proof.

The manufacturers below are expected to meet or supply the instruments required in

the production of steam.

List of Manufacturers/suppliers: to follow

For the selection of instruments,

Rosemount instruments are taken into consideration as well as Fisher in

selecting the appropriate valves for the process.

4.0 SUPPLY SYSTEM

Power supply of the control system shall be of highest available quality for

reliability and long service life. Power supplies for all transmitters, controllers, signal

converters, electric system and components in shutdown system shall be supplied from

UPS. Power distribution to each instrument shall be through proper, independent switch

and fuse. Protective fuses shall be of indicating cartridge type mounted in fuse holders.

4.1 ELECTRICAL

In general, the following Power Supplies shall be used for instrumentation

and Control: -For Process Platforms: 220V AC + 5%, 60HZ + 1% (UPS) for all

instruments control. However, all components e.g. instruments, system shall be

suitable for 220 V + 10% AC, 60 Hz + 3%; For Process & Well Platforms: 24V




Rev. No. A


DC + 5% Battery Negative earthed for Platform interlock system, solenoid valves,

fFire and gGas system and status lamp.

. 4.2 PNEUMATIC

For pneumaticPneumatic instruments, dry instrument gas / air supply

compressor output shall range from shall 100 psi minimum to 200 psi. For

pneumatic valve actuation, the operating air supply pressure shall range from

120 psi to 150 psi.be as follows:

100 psi (minimum)

200 psi (normal)

300 psi (maximum)

5.0 EQUIPMENT PROTECTION

Since a process involving geothermal is hazardous, all aspects involve in here

must be clearly stated and finalized. One of the most important parts of a system is the

equipment. Without these equipments, a system can’t be operational and so, for the

safety of this equipment, certain protection is defined.

5.1 ENVIRONMENTAL PROTECTION

All instruments/equipments must be suitable with the working environment

as well as its position whenn the installed. The basis for installation should also

consider equipment exposure to several factors like wind, temperature, vibration,

shock and many others. It must also withstand these conditions during shipment

or storage.

Trigon, 03/01/15,

Please make sure that all the electrical and pneumatic supply are based on the process.




Rev. No. A


5.2 INGRESS PROTECTION

All field instruments shall have ingress protection to IP 65 or better.

Pneumatic field instruments used for control applications shall have ingress

protection to IP 55 or better. All instruments installed inside pressurized

equipment / control rooms shall have ingress protection to IP 42 as a minimum.

5.3 TROPICALIZATION

All electrical components shall be tropicalized to protect against humidity,

moisture and fungal growth by means of hermetically sealed units, protective

coating on circuit boards, gold plated edge connectors, etc.

5.4 HERMETIC SEALING

All relays and switches shall be hermetically sealed, and those utilized in

24 V DC control logic circuits shall have gold plated contacts rated 0.5 Amp at 24

V DC. Those interfacing with field equipment shall be rated 2 Amp 24 V DC.

5.5 HAZARDOUS AREA INSTRUMENTATION

The Contractor shall classify hazardous areas in accordance with API 500

and specify various equipments accordingly. All instruments which are mounted

outside of normally pressurized control / equipment rooms shall be certified by

bodies such as FM / UL / BASEEFA / CSA / DGMS / CMRS for use in Class I,

Division I, Group D, T3 hazardous area, even if the instrument’s location is

classified as a normally non-hazardous area. Intrinsic safety approval shall be




Rev. No. A


based on entity concept and necessary compatibility checks shall be carried out

by Contractor before selecting any equipment. Intrinsically safe protection using

external barriers shall be provided for all process transmitter loops (closed as

well as open). Isolating barriers shall be of the plug-in type, mounted on modular

back plane termination units. Each input and output in a loop shall have a

separate barrier. No barrier shall be shared between two loops in input / output.

All other instrument loops shall be provided with explosion proof / flame proof

protection. Solenoid valves, electric hand switches, signaling lamps and Intercom

/ Paging system shall be Explosion proof / flame proof to Ex d or NEMA 7. If

specialist instrumentation cannot be provided with the above methods of

protection, then alternative methods suitable for the classified area and certified

by an acceptable Authority may be proposed. The Contractor shall submit a

technical report justifying the instrument selection for the Company’s

consideration.

5.6 R F INTERFERENCE

All equipment shall remain unaffected by radio transmissions (Levels of

permissible RFI shall be as per IEC 801). Band-pass and / or band stop filers

shall be fitted, as necessary.

5.7 SEALING

Seal systems shall be used to isolate instrument from the process fluid

encountered in the following services:

a. Wet gas, which may condense in the instrument lines.




Rev. No. A


b. Process fluids that vaporize condense or solidify under operating pressure and

ambient temperature.

c. Process fluids that will subject the element to high temperature.

d. Process fluids that will subject the element to high temperature.

e. Viscous liquids.

Sealing may be accomplished with diaphragm seals. All venting

instrument and pilot valves shall have bug screens fitted to atmospheric vents.

6.0 EARTHING SYSTEM

Safety of the system as well as its people is the two most important aspects to be

considered. Earthing system is provided to protect a system from sudden mishap or

short circuit that can harm lives of inhabitants.

6.1 ELECTRICAL SAFETY EARTH

Bonded to the site structure and utilized for electrical safety of metal

enclosures and chassis on all instrument and electrical components.

6.2 INSTRUMENT CLEAN EARTH

Instrument clean earth will serve as basis for the earthing of DC instruments that

are usually located near or inside the control rooms. Data and communication busses

are earthed due to vulnerability of low level CMOS and microprocessor circuits and to

prevent noise interference or risk of data/communication loss.




Rev. No. A


6.3 INTRINSICALLY SAFE EARTH

Process equipment such as motors, lightings, and power distribution

system which runs at 120VAC, 220VAC and 480 VAC are power earthed due to

high current level switching and to prevent radio frequency or electromagnetic

interference.

.

7.0 CABLE REQUIREMENTS

A well-designed and applicable system cable is necessary to achieve the

required performance of the system.

7.1 CABLE TYPES

There are several cable types for each area to be used for. Certain

standards must be followed in choosing the right cable for each function. The

inner and outer jacket of the cables shall be made of extruded flame retardant

194 °F PVC to IS 5831 type ST2. The O2 index of PVC shall be over 30. The

temperature index shall be over 482 °F.The following products shall be within the

jurisdiction of this Group: NEC, NEMA and, IEC.

7.1.1 INSTRUMENT CABLE

Cables with soft annealed bare or tinned copper conductors and

PVC flame retardant insulations and jackets are the standard offering for

300V Power-limited tray instrumentation installation. The specified cable

to be use is #18 AWG, 8 pair tinned copper conductor with PO (Polyofelin)

insulation.




Rev. No. A


7.1.2 SYSTEM CABLE

The core of a single-mode fiber is smaller (<10 micrometers) and

requires more expensive components and interconnection methods, but

allows much longer, higher-performance links. Installed cable shall be

8.3/125micron core/cladding, single mode, and graded index glass fiber.

All materials in the cable are to be dielectric. A multipair shielded #20

AWG type of cable is used in the system. It is made up of copper with

PVC jacket material.

7.1.3 SIGNAL CABLE

Typical cable shall be #18 AWG twisted pair, PVC insulation, braid

or foil shield, with drain wire, PVC jacket with rated voltage of 220-

600VAC. The drain wire shall be connected at one end of the cable

choosing the end with the lowest impedance ground source.

Multi-pair cables shall have the following additional features:

Color coding or tagging of the wires.

Individual pair shielding apart from overall shielding.

Maximum of 12 pairs per cable




Rev. No. A


7.1.4 POWER CABLE

Power Cables shall be PVC sheathed 3 core, minimum of 2.5mm2

conductor area (Max. conductor resistance of 7.41Ω/km), 0.9 mm nominal

thickness of insulation, and minimum thickness of inner sheath of 0.3mm.

7.1.5 JUNCTION BOX CABLE

Instrument cable and signal cable are terminated inside the junction

box. Typical cable shall be #18 AWG shielded twisted pair. The specified

home run cable used is a traditional MC Cable with interlocking metal-tape

armor. This MC Cable carries no limit of current-carrying conductors as

per NEC® Table 310.15(B)(3)(a). Several cable types are used for

different junction boxes.

JB No. Cable Type

DJB-A-001 1 pair

DJB-C-003 2 pair

DJB-A-001 8 pair

DJB-A-003 5 pair

DJB-B-001 6 pair

DJB-C-003 2 pair

AJB-A-002, AJB-C-004, 2 core

AJB-A-002 18 core




Rev. No. A


AJB-A-004 25 core

AJB-B-002 12 core

AJB-C-004 28 core

7.2 CABLE IDENTIFICATION

All wiring, cables, tubes, multi-tube bundles, junction boxes and auxiliary

equipment shall be suitably identified clearly as per tag or addresses. Plastic

adhesive tapes shall not be used for instrument identification. All wiring shall be

tagged with slip on or clip-on wire marker at both ends with the wire number

specified on the drawings.

Terminals for power cables, polarity, ground connection, shall be identified

according to the specified tag.

Cable cores shall be colored as follows:

24VDC Digital Circuits: Positive: Red, Negative: Black, Ground: Yellow green

Analog Circuits: Positive: White, Negative: Black

Cable outer sheaths shall be colored as follows:

Intrinsically Safe: Blue

Non-IS Cables: Black

Trigon, 03/01/15,

Pakicheck din to.pwede kayo magtanong sa naka-assign sa cable listing.

Trigon, 03/01/15,

Please make sure that all cables involved in the process are applicable.




Rev. No. A


7.3 CABLE SHIELDING

All instrument signal cables shall be braid/foil shielded/shield grounded at

the same point as the signal circuit.

7.4 CABLE MARKING

All cables shall be identified with stainless steel cable markers securely

fixed to the cable with cable tie wraps at the following locations:

All cable glands

Entering and leaving cable ladders, ducts, and supports

Both sides of walls or bulkheads

Cable markers shall be fitted during or immediately after cable termination.

7.5 CABLE RUNS

All cables going to and from control panels shall be supported with the

cable manager or tray. Power cables shall not be combined along with the

control cables in one cable manager. Cables in intrinsically safe circuits shall

preferably be not run in the cable manager for cables in non-intrinsically safe

circuits. If run in the same cable manager, a metallic earthed separator shall be

provided. Conduits carrying intrinsically safe cables shall be painted with the blue

color bands at each end.

The entry and exit of the conduit shall be smooth and free from burrs.

Cables shall be put inside the conduit to prevent damage. Splices shall be made

Trigon, 03/01/15,

Research further. Include the material type and size of conduit and cable runs.

Trigon, 03/01/15,

Research further

Trigon, 03/01/15,

Paki-verify maigi to kasi baka maquestion .you can ask ne or jeff about shielding




Rev. No. A


only at the end of each terminal of the instrument cables going to the junction

boxes.

7.6 CABLE INSTALLATION

All cables including serial link and data highway cables going to or from

the equipment rooms shall be armored and continuously screened with screen

grounded at the equipment room end only.

For ease of instrument disconnection, an adjustable elbow or union shall

be provided between the terminating gland and the instrument.

A neat loop of 250mm diameter shall be left immediately adjacent to all

instrument devices in the field.

Cabling for locally mounted instruments carrying sensitive signals and

normal/emergency walkways or other installation that can interfere with the

equipment shall be separated.

Cable transits shall be used to provide gas-tight cable penetrations

through decks or firewalls.

7.7 CABLE TERMINATION

All cable glands shall be double compression type and explosion proof.

Cable glands subjected to salt water spray shall be weather proof. All

terminations shall be screw type terminals for 2.5mm2 conductors (minimum)




Rev. No. A


Insulated crimp lugs shall be used for all cable core connections, with only one

conductor per terminal side.

Cables shall be terminated in 316 SS glands. The inner sheath shall be left

on the cable after the gland, and removed at the point of entry into wiring duct.

Cable cores shall not be “pig-tail” finish. Electrical tapes or other safety

accessories shall be provided for safety.

Cable screens and drain wires shall be securely insulated at the final field

termination.

The communications conductor of a cable shall be terminated in the bottom

terminal of a row of terminals.

Printed sleeve-type ferrules shall be used in both terminals of control wires

or any other cables depending on the size of the wire being used.

Only one conductor shall be used per terminal side.

Cable entry to control room/ other rooms shall be through listed multicable

transits.

Terminal blocks shall be vibration proof, din rail mounted, stack on type and

shall use screws for terminals. Fused terminal blocks shall also be used for

safety purposes. Termination of shall be through the use of wire lugs / ferrules.




Rev. No. A


Cable termination of skid items: Manufacturer supplying skid mounted

equipment or vessels with instrumentation (alarms, shutdowns, control functions)

shall be accessible and terminated on a central junction box near skid boundary,

available for hook up by contractor.

B. CONTROL

1. INTRODUCTION

Geothermal powerplant separator, scrubber and brine disposal system

process control shall be according to DCS and PLC control system. User

interface and remote control capability of the said types of control are the basis

for control for the processes involved. Less human intervention shall be adopted

using the advanced control system.

2. OPERATION SYSTEM

Central DCS located at control room shall monitor and control all process

units for the entire project. Control room shall provide adequate space and

guarantee a safe, effective and efficient control and monitoring of the plant. Every

major and minor unit of the plant shall operate independently from its dedicated

console, providing machine edition HMI and VDU-based DCS Monitor Interfaces.

Each of these consoles shall have 32” LED monitor.

The DCS operator interface (VDU based) shall be the primary integrated

window for operation of the control and safeguarding systems and shall provide

access to:

Trigon, 03/01/15,

Include PLC

Trigon, 03/01/15,

Paki-check if applicable sa process natin.




Rev. No. A


1. Process Control

2. Sequence Control

3. Equipment Status

4. Alarm Overview

5. Trip Status Overview

6. Real-time Trending

7. Fire and Gas Detection Status

2. SAFEGUARDING SYSTEM

The main objective of the plant and its control system is to, safely, reliably, and

continuously produce on-specification product. Without compromising these objectives,

the control systems shall also be designed to maximize plant availability, minimize plant

energy consumption, adverse environmental impact and requirements for operator

interventions. The principle objective of the safeguarding systems is the protection of

personnel, environment, plant and equipment and the maintenance of safe operating

conditions compatible with production requirements.

This shall result in control and safeguarding design that is:

1. Safe

2. Simple to maintain and operate

3. Reliable and flexible to accommodate changes in technology and

operating requirements.

4. Low cost




Rev. No. A


3. EQUIPMENT LOCATIONS

The location plan for equipment installation shall be based on methods where

instruments are accessible for maintenance. Instrument installation shall be based on

the manufacturer’s specifications.

3.1 METHODS

Two general methods are used to position equipment:

Group Pattern where vessels, exchangers, columns, pumps and

etc., are group in separate areas. This method shall be applied in

the project.

Flowline Pattern where equipments are laid out as arranged in the

process flowsheet.

For the process, a compromise between the two shall be used for ease of

operation and maintenance.

3.2 ELEVATION

Heavy and bulky units such as columns, tanks, and etc. shall be

placed on the ground with proper support to avoid high expense of

elevating equipments.

Therefore, pumps or other equipments shall be used to force the

fluids to flow unnaturally.




Rev. No. A


3.3 OPERATING CONVENIENCE

Equipments requiring frequent attention shall be grouped together

to facilitate operation and maintenance. However, the safety

clearance between the units has to be observed to ensure safest

possible arrangement and the most hazard prone equipment shall

be placed at the location most convenient for it to be removed.

Equipments that provide local indication shall be mounted within

eye level for ease access of operator.

A rectangular setup with a central overhead pipe rack permits

equipment to be installed along both sides of the pipe way with

ease of access.

3.4 PLANT EQUIPMENT LAYOUT

Pumps shall be located in line along each side of an access way

with the motors aligned outwards for easy access and

maintenance.

Equipments requiring large cranes for services shall be located at

the perimeter of the rectangular set up, adjacent to the main road.

Compressors shall be installed to allow for rapid dismantling and

reassembly thus avoiding from the needs to have a standby unit.

Compressors with bottom suctions and discharge connections shall




Rev. No. A


be used, supporting it on a platform above ground level

(approximately 2.5 m or so).

4. BASIC CONTROL AND MONITORIING

This level comprises basic control and monitoring of process, utility,

equipment and auxiliary systems and is implemented in DCS. These

functions can be categorized as follows:

4.1 UNIT MONITORING

Unit monitoring comprises all Human Machine Interface (HMI)

function provided to those responsible for monitoring and control of the

process and its environment. These includes alarm and monitoring

display, group and detail displays, custom graphic displays, data historian

and retrieval, reporting, etc.

4.2 REGULATORY CONTROL

Basic regulatory control provides closed loop control functions for

stable and safe operation around steady points of operation. The basic

control functions comprise mainly of flow, level and pressure control loops

required as a minimum to operate and control the process. These loops

may include extended regulatory control functions such as: split range

control, override control, ratio control, and cascade control. They may also

include control based on calculated variables, such as heat duty control,

pressure compensated temperature control, etc. all of these shall be

realized on the central DCS system only.




Rev. No. A


5. BASIC SEQUENCE, CONTROL, LOGIC, INTERLOCKS

All Sequence control, interlocks and logic shall be realized in the central DCS to

provide automatic performing of task in a defined sequence.

5.1 SEQUENCES

Sequences shall be used where appropriate for frequently repeated

series of control actions. All sequences shall include feedback for the

operator of the current step and status of the sequence. All transitions

must be configured with an alternative path in the event of the failure of an

action that drives the process to a safe state. If possible, large sequences

should be broken into smaller components that can be activated from a

supervisory sequence. For example, if a pump with inlet and outlet valves

is part of a sequence, the pump start/stop can be made into a smaller

sequence called from the main process sequence.

5.2 INTERLOCK

Interlocks refer to logic that would be used to control the operation

of devices. In general all interlocks must default to a state that would drive

the process to a safe state. Any interlocks that are uncertain or have bad

signals transmission would be assumed to be in the fault state. The

system will be configured to include bypass interlocking operation

whenever presence of inconvenient process occurs.

Hardwired Interlock

A signal wired directly to the motor control relay. Hardwired

interlocks may be required by construction codes or for fundamental




Rev. No. A


safety. These interlocks could only be bypassed by inserting jumpers in

the field which should never be required.

Safety Interlock

A logic required for the safe operation of a device and

equipment protection. These interlocks cannot be bypassed except by

changing the control logic.

Process Interlock

A logic required for the normal operation of a device in the

process. In local mode process interlocks could be bypassed. In the

transition to remote mode, all process interlocks would be activated.

Permissive

A condition that must be true for a device to change state but

when the state has changed it would be ignored.

All interlocks, except permissive, would be latched in the control

system and require acknowledgement by the operator. Motor controls

would only start on a direct start command and would not be set to trigger

when an interlock clears or is acknowledged.

6. DCS DESIGN REQUIREMENTS

The process shall have workstations, for control, for monitoring, for

maintenance, and for data archiving. Control shall be centralized in

Trigon, 03/01/15,

Since may changes sa system archi. Pakidagdag:*PLC design requirements*HMI design requirements




Rev. No. A


one control room. Each workstation must compose of one engineer

to monitor the plant operation. EXIDA will be used to provide

functional safety and security software feature in the system.

Redundancy of smart switch must be provided for 100% reliable

communication.

The DCS shall be using Delta-V S series controller for economical

and reliable control of the plant. Also SIS (Safety instrumented

System) as supported by S-series, will be used for safe and

maintainable control of ESD devices and MCC (Motor Control

Cabinet) devices. Stand-by controller or a redundant controller

must be used as a backup control for emergency situation.

Redundancy of controllers, power supply, network switch, I/O

modules and other significant devices must be provided as a

backup during emergency situation, e.g. emergency shutdown.

The controllers must have enough number of AI, AO, DI, and DO

modules to support digital and analog devices. Also it shall support

HART devices, thus it must contain HART module.

Complete software, hardware, and communication load shall not

exceed 50% system load even after the complete implementation

of project and running pick load. This also includes redundant

processor.

The system shall have 50% margin in software memory load for

future spare addition without replacing or upgrading existing system




Rev. No. A


hardware or software at all levels. Also it shall be capable of

loading up to 100% without overrun or degradation of performance.

It also must report all type of load limit alarm, diagnostic alarms up

to channel level, communication alarm system, hardware failure

alarm and other global information with alarm facility on engineering

or operator station in real time with 1 second resolution.

System shall support various types of control, interlock, sequence

algorithm and shall also support various types of high level

programming language like function block and sequential function

chart in real time control application in addition to standard control

algorithms available in DCS.

The system shall also support several of hourly shifts, daily and

monthly, report logs, totalizes reports, snap shots reports, etc in

Microsoft excel format only. The layout and type of reports or data,

number of tags per report, etc shall be as per owner’s requirement.

All operator stations and engineering stations shall be equipped

with MS Office license copy. And system shall support minimum of

1000 tag historian software at 1 second interval.

Purchaser shall provide 230Vac +/- 10% at 50Hz -3/+1 Hz, UPS

grade, floating/grounded power supply for complete DCS system at

cabinet room. All digital inputs shall have 24Vdc interrogation

voltage level. All digital outputs shall drive 24Vdc, 2 NONC, socket

mounted, interposing relays with 230D AC/5Amp contact ratings.

All field loads from digital output, including solenoid valves, MCC

switch gear signals, etc. shall be interfaced via these interposing




Rev. No. A


relays only to avoid interference problems in low voltage instrument

signal cables.

There shall not be any interposing relays for field Digital inputs but

all MCC digital inputs shall be wired to DCS via interposing relays.

While preparing the DCS database, all configurations like graphic

symbols, color codes, control or logic schematics, etc. shall be

based on ISA standards.

7. SYSTEM ARCHITECTURE

7.1 NARRATIVE

The proposed DCS System Architecture for Geothermal Power Plant

Separator, Scrubber and Brine Disposal System is composed of five workstations. It

includes Delta-V Pro-plus for Engineering Workstation, Operator workstation, AMS

Suite for Maintenance workstation, OPC server and Historian workstation for alarm

logging. These workstations gather the data from field devices to execute commands

and to monitor the status of field devices for maintenance purposes.

Delta-V Pro-plus is used in engineering workstation, where the operator or

an engineer has an access in making changes in the control system program. Since

Operator workstation is for monitoring and manually operating the system, it does not

need any Delta-V Pro-plus. AMS Suite for maintenance workstation is used to monitor

field devices status, whether they should be calibrated or replaced with other devices,

this intelligent device manager avoid further damage of the field devices and secure that

plant operation is efficient. Historian workstation archived all the alarms and log errors

Trigon, 03/01/15,

May changes sa system archi. Please check




Rev. No. A


to trace them and monitor that the process is in its normal state and is efficiently

running.

These workstations communicate with two smart switches via Industrial

Ethernet to avoid error in delivering the signals from the controllers to the workstation.

Redundant S-series controllers and SIS (Safety Instrumented System) are useused as

a back-up if the active controllers fail to work. SIS or Safety Instrumented System

controller is used for those ESD field instrument. HART module is used for HART

(Highly Addressable Remote Transducer) devices. All digital devices will only be in a

conventional type of wiring. A motor control cabinet (MCC) is provided for centralized

control of motor. All MCC devices are controlled by active S-series controller and SIS

controller for safety control via interposing relay cabinet to avoid interference problem in

low voltage instrument signal cables and communicate via HART protocol.

7.2 DRAWING

(See Document No. PIC-E-SYS-396-001)

C. SAFETY

1. INTRODUCTION

Trigon, 03/01/15,

Please include the layers of protection (detailed) na ggamitin sa process natin. May figure nun e about sa layers of protection pasearch na lang.Under alarms, Paki-include yung action for example: LALL- off LCV blah blah..




Rev. No. A


The production of steam can acquire can cause several types of hazards which

are being pre-determined to evaluate the appropriate safety standards to be followed.

These standards are guidelines for the purchase of materials that are applicable for

the area that is classified according to the hazards that are most likely to occur and for

personnel safety considerations. Potential hazards include process hazards, presence

of flammable fluids and combustible gas or vapors, and toxic gases.

Area classifications are based on the presence of possible cause of hazards that

are pre-determined and assumed in a specific location. The most commonly used

codes are from IEC/NEC standards which defines the level of hazard present that may

affect process equipment and personnel’s health.

Geothermal process hazards are due to the critical temperature and pressure by

which the control system is operating. Another hazard that must be put into

consideration is the emission of hydrogen sulfide and CO2. Hydrogen sulfide is a

highly flammable, explosive gas, and can cause possible life-threatening situations if

not properly addressed. In addition, hydrogen sulfide gas burns and produces other

toxic vapors and gases, such as sulfur dioxide. Excessive amount of carbon dioxide

released to the surface is health threatening and creates environmental issues. At this

stage government involvement is felt.

Basis of Safety and Layers of Protection

Plant safety integrity can be measured by the level of protection it applies. Safety

starts with the basic control system. The BPCS or the basic process control system




Rev. No. A


provides significant safety through proper design. This automatic sequence has

already considered safety procedures but is not reliable enough to sustain external

sources of hazards. Sometimes the equipment itself can be the source of unsafe

process control. Process equipment exposed to high temperature and pressure and

corrosive environment application are prone to deterioration.

The next layer is still based on the control system wherein automated shutdown

routine is enforced as long as it is within the scope of the configured cause and effect

matrix.

The next layer for protection is the intervention of the operators. In this situation

the accurate decision making determines whether alarming condition can be put into

stabilized state. Operators shall follow enacted protocols as a guide to proper response

to emergencies whenever it occurs.

Another high degree of protection uses automatic SIS. The safety instrumented

system is based on ANSI/ISA 84 functionality safety standards which state the

requirement under IEC/NEC 61511. Automatic SIS does not only include the process

level safety but also for the safety of the personnel. By integration of fire and gas and

basic process control system emergency detection the automatic, SIS is able to

determine the action to take. These actions are configured in the engineering

workstation. Safety instrumented system is also capable of diagnosing the process

equipment reliability.

The next active layer is by means of rupture disks, valves, etc.to mechanically

release process variable at an uncontrolled stage and prevent explosion or fire.

The final layer is the emergency response which includes evacuation plans,

firefighting, etc. and means to minimize ongoing damage, injury or loss of life. Plant

safety regulating body shall impose protocol whenever an emergency occurs. They

shall also assigned areas for evacuation which shall be designed to be accessible all

the time. These areas must be safe all the time even during presence of hazards in




Rev. No. A


other plant areas. Medical teams and means of transport for evacuation shall also be

considered due to critical process environment.

2. Safety System (Fail Safe Action)

Geothermal power plant process control system safety and efficiency shall not

only be based on the configured final control element response to configured sequence.

Programmed sequences are dependent on system supplies such as pneumatic and

electrical supplies. When these supplies fail, process sequence are interrupted which

will make process control unstable. Fail safe actions must not be dependent on the

program which the final control elements follows but must beare mechanically capable

of giving the safest possible position in case power interruptions occur. The required

predetermined control element’s fail-safe actions of final control elements areis shown

in Table 1. Also, provided at Table 2 is the action taken at a specific process alarm

condition..

Table 1. Control Element Fail Actions

Tag No.Loop

No.Description Service Fail action

LCV-103B L-103B Level control valve Discharge saturate to D-1200 Fail-to-open

LCV-103B L-103A Level control valve Discharge saturate to D-1100 Fail-to-open

LCV-104 L-104 Level control valve

-Brine disposal to wells 33,77,

31A, 50 & binary

-To hot brine injection

Fail-to-Close

LCV-504 L-504 Level Control Valve-Condensate discharged to

sump S-1100Fail-to-Open

PCV-505A P-505A Pressure Control Valve -Reduce outgoing steam Fail-to-Open




Rev. No. A


pressure to secondary rock

muffler (M-700)

PCV-505B P-505B Pressure Control Valve

-Reduce outgoing steam

pressure to secondary rock

muffler (M-700)

Fail-to-Open

Table 2. Alarm Summary and Actions

ALARMS

Loop

No. Description Actions

LAH-102 L-102 Level alarm high Start P-300B, opens LCV-103A

LAHH-102 L-102 Level alarm very high Start P-300C, opens LCV-103B

LAL-104 L-104 Level Alarm very low Disables AVS-102

LALL-104 L-104 Level alarm very low Trips P-300A and Closes LCV-104

PAH-306A P-306 Pressure Alarm High Trips P-300A

PAH-306B P-306 Pressure Alarm High Trips P-300B

PAH-306C P-306 Pressure Alarm High Trips P-300C

PAH-105 P-105 Pressure Alarm High Trips all active brine pumps

LAH-203 L-203 Level Alarm High Start P-200

LAL-203 L-203 Level Alarm Low Stop P-200

dPAHH-301A P-300

Differential Pressure Alarm

Very High Trip P-300A

dPAHH-301B P-300


Very High Trip P-300B




Rev. No. A


dPAHH-301C P-300


Very High Trip P-300C

VAH-302A/B/C

V-300A/

B/C Vibration Alarm High Operator action/SIS

PAH-306A P-306 Pressure Alarm High Trip P-300A

PAH-306B P-306 Pressure Alarm High Trip P-300B

PAH-306C P-306 Pressure Alarm High Trip P-300C

PAH/PAHH-

305A/B/C P-305

High and Very High

Pressure Alarm

Close LCV-104 on condition that all Brine

Pumps are tripped

LAH-401 L-401 Level Alarm High Start P-400A/B

LAL-401 L-401 Level Alarm Low Operator Action

LALL-401 L-401 Level Alarm Very Low Trip P-400A/B

FAL-308A F-308 Flow Alarm Low Trip P-300A

FAL-308B F-308 Flow Alarm Low Trip P-300B

FAL-308C F-308 Flow Alarm Low Trip P-300C

LAHH-502/

LAHH-503

L-502/L-

503Level Alarm Very High

Disable AVS-502B, Open LCV-504 and

closed solenoid valve for PCV-505A and

PCV-505B air supply.

LAH-502B/

LAH-503

L-502/L-

503 Level Alarm High Disable AVS-502B, Open LCV-504




Rev. No. A


2.1 System Architecture (Delta V SIS)

The integrated Delta V SIS in the system architecture shall have a

separate controller from the basic process controllers to achieve a higher degree of

plant and personnel protection and in compliance with IEC 61508 and IEC 61511

standards. The geothermal process control system shall have a redundant safety

instrumented system to maximize safety and efficiency within process control.

Safety instrumented system is composed of any combination of sensors, logic

solvers, and final elements which is separated from the process control system.

This can include safety instrumented control functions, safety instrumented

protection functions, or both.

The role of the workstations for safety purposes in the system architecture is as

follows: 1.) Proplus Station for cause and effect matrix configuration; 2.) Operator

workstation for process monitoring and remote intervention to process controls

specially during occurrence of process emergencies; 3.) Application workstations

(Historian) for alarm data archiving coming from process control transmitters and

fire and gas detectors; 4.) Application workstations configured as OPC is

responsible for open communication between devices with different protocols and

5) Application workstations for maintenance which diagnose process equipment

problems before they occur. The communication between controller and

supervisory level will be made possible using Ethernet.

The Delta V SIS controller will act as back-up system for which the main purpose

is to monitor continuously the ability of sensors, logic solvers, and final elements to

perform on demand, with faults diagnosed before they cause spurious trips and

implement response to alarms in case the basic process control system fails.

Unstable process control results to alarming conditions that affects plant integrity in

operating at stable and safe conditions.




Rev. No. A


3. Emergency Shutdown System

The imposed safety system will include an emergency shutdown that is not

dependent on loop action as it independently shutdown control elements. The ESD

system is integrated in to the fire and gas system where both prevent and provide safety

from incidents and unnecessary shutdowns. All plant areas will be provided with safety

fire and gas detecting instruments in compliance with the standards imposed by the

regulating bodies for safety.

ESD system shall be hierarchal. Minor alarm action will trip an instrument so that

technicians can troubleshoot the area affected. Hierarchal ESD minimize dead time

costs or losses due to production loss.

An overall shutdown will be located at the central control room. The officers-in-

charge or authorized personnel are responsible in tripping this centralized ESD push

button except for extreme and critical situations. Safety board will assign level of

alarming condition where crews nearby can use this emergency button.

Strategic location for ESD stations with panels for system conditions, alarm

monitoring and location of affected area will be provided. Response is predetermined for

officer in charge to choose the corresponding action to a specific alarm condition. Push

buttons installed for a specific emergency response are hard-wire and normally de-

energized to prevent short circuit, line breaks, or ground fault. ESD can also be initiated

using the safety console integrated into the control system. Only authorized personnel

can activate the ESD.




Rev. No. A


ESD initiation will be based on the following:

ESD TYPE RESPONSE

ESD #1 Unit shutdown

ESD #2 Process Shutdown

ESD #3 Over All shutdown

ESD Summary

Process Emergency Status - Initiate fail safe actions

Fire Emergency Status - ESD initiation is based on fire alarm status

Gas Emergency Status - ESD initiation is based on gas alarm status

3. Leak Detection System

Process equipments which areis responsible for process variable such as steam,

brine and fresh water supply transmission shall be monitored to keep thesethese

equipments reliable in transmitting the expected process output.

A level transmitter is integrated in all non-submersible pumps to detect fluids that

comesfluids that come out from these pumps. The transmitter will link its

measurement to the SIS controller to give the corresponding action to take. The

action usually taken at this condition is tripping the working pump and gives its work

to a back-up pump.

4. Fire Detection System

The fire detection system is integrated into the design to minimize risk of

equipment destruction and personnel safety. Smoke detectors and other fire




Rev. No. A


detecting instruments are looped separately from process design but are integrated

into the delta V SIS for to provide interlocks to process equipment and provide safety

action in case fire occurs. Multiple installation of fire detecting instruments in an area

will increase the accuracy in terms of locating the defective area. Fire detecting

instruments are hard wired to delta V SIS controllers therefore special modules will

not be required.

Operator interfaces and indicators shall be installed to determine level of risk and

location of fire. Stations for manual fire alarm trigger will also be installed in different

plant areas. When these alarms are triggered by officers in charge, it usually intends

to imply a heightened level alert and response would be overall emergency

shutdown and evacuation. Personnel are obliged to report emergency status and

provide appropriate response to these alarms.

Fire detector output such as audible and visual consoles will be based on how

critical the present situation is. This is to provide accurate response in case fire

occurs.

Below are areas within geothermal power plant that are prone to fire and explosion.

Location # of Detectors ESD InitiationActive Alarm Consoles

HMI Audible Visual Workstations

Separator Multiple detection ESD #1-2

Scrubber Multiple detection ESD #1-2

Flash tanks Single detection ESD #1

Pipelines Multiple detection ESD #1-3




Rev. No. A


Level Drums Single detection ESD #1-2

Control Room Multiple detection ESD #3

Other control

system loopsSingle detection ESD #1

5. Gas Detection System

Gas detection system comprise of instruments that measures level of risk once

an unstable amount of toxic gases or combustible gases reaches the surface or

exposed to an area. These gases are usually in the form of carbon dioxide and

hydrogen sulfide. Gas detectors are either installed at multiple points in an area or

single gas detectors.

Alarms will only read normal gas condition, toxic or combustible gas level rising

and alarming level of gas detected.

Gas detection system does not require special module in a controller. Its 4-20

mA signal to controller can support interfacing with the controller level and into the

supervisory level for complete safety compliance with IEC 61511.

Plant areas that usually exposed to this combustible and toxic gas are usually

found in venting areas. These areas include the well-field and the plant-site vent

mufflers. Pipelines will also be provided with gas detectors for cases where leaks occur.




Rev. No. A


Graphical and tabulated data will be recorded in the in the historian workstation

for periodically evaluation of plant safety status. Location, alarm status and options for

alarm action will be displayed in HMI’s and workstations.

Below are the details for gas detection locations, console and ESD response

Location # of Detectors ESD InitiationActive Alarm Consoles

HMI Audible Visual Workstations

Separator Multiple detection ESD #1-3

Scrubber Multiple detection ESD #1-3

Flash tanks Single detection ESD #1-3

Rock mufflers Single detection ESD #1

Pipelines Multiple detection ESD #1

Level Drums Single detection ESD #1

Well Field Multiple Detection ESD #3

6. Audible and Visual Alarms

OSHA standards and guidelines which focus on the personnel safety shall be

implemented as well as the general industry standards. Installation of audible and visual

alarms especially for remote plants comply the requirements stated by the said

standards. To alert the personnel in case of emergency is the main objectives of these




Rev. No. A


alarm hardware. Indication of these consoles shall only mean occurrence of

emergencies involving life threatening events.

The design for geothermal plant alarms shall indicate the following events:

Visual alarms (in the form of emergency lamps)

Indications:

Green – plant operating in normal condition

Yellow – presence of unstable process/environmental issue

Red- ESD 3 response or evacuation

Audible alarms (usually Beacons/ Alarm Bells)

Indications:

No sound - Plant operating in normal conditions

Non-continuous sound - presence of unstable process/environmental issue

Continuous sound - ESD 3 response or evacuation

D. NAMING CONVENTION

1. SCOPE

This document contains the naming convention of different deliverables, and

used as a reference for easy identification of each part.

1. NAMING CONVENTION

The naming convention of each deliverable can be determined by the following:

“X” symbolizes alphabet letters (e.g. A, B, C, D…)

“0” symbolizes numbers (e.g. 0, 1, 2, 3..)

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CLASSIFICATION

BASIS OF DESIGN Sheet



Rev. No. A


1. DOCUMENT/DRAWING

XXX – X – XXX – 000 - 000

Example: PIC-E-PID-396-001

Company Name – PIC (Process Instrumentation Company) is the company

name used in this document.

Classification – To determine either Engineering (E) or Design (D) is

involved in the deliverables.

Deliverable - The list of requirements provided by the company.

No. Code - This is used for determining the main deliverables.

Sheet No. - This is used for determining the subtopics of main deliverables.

Abbrv. Description

PID Process and Instrument Diagram

NTV Narrative

SARC System Architecture

SPC Specification

SHT Data Sheet

INDX Index

SHEET NO.

NO. CODE

DELIVERABLE

COMPANY NAME




Rev. No. A


IOL I/O List

JBL Junction Box List/Schedule

CBL Cable List/Schedule

IAM Instrument Air Manifold

WRG Wiring Diagram

LPD Loop Diagram

LOC Location (JB/IAM)

INS Installation

DELIVERABLES NO.CODE

Abbrv. DescriptionNo.

Code

DWG Drawing 396

NAR Narrative 627

IDX Index 439

SPC Specifications and Datasheets 773

LST List 578

SCD Schedule 723




Rev. No. A


2.2 JUNCTION BOX

XXX – X - 000

Example: DJB-A-001

JUNCTION BOX NO.

AREATYPE OF SIGNAL




Rev. No. A


Type of Signal - The instrument’s signal type can either be Analog (A) or

Digital (D). After determining its signal type, “JB” initials is followed which

stands for Junction Box.

Area- It represents “A” which stands for Area.

Junction Box No. - It identifies the number of junction box within the area.

2. DEVICE CABLE

XX – XXX - 000

Example: DC-LSH-102

Device Cable- It represents “DC” which stands for Device Cable.

Instrument Tag No. – The instrument tag number is based on its function

and loop in the process.

3. SYSTEM CABLE

XX – XXX - 000

Example: DC-LSH-102

System Cable- It represents “SC” which stands for System Cable.

INSTRUMENT TAG NO.

DEVICE CABLE

INSTRUMENT TAG NO.

SYSTEM CABLE




Rev. No. A


Instrument Tag No. – The instrument tag number is based on its function

and loop in the process.

4. LINE

0 – XX – X/X000 - X/X000 - 00

Example: 24”-CS-D1100-T100-01

Size- It indicates the pipe size in the process line, and usually measured in

inches.

Material- The pipe in the process is made of carbon steel (CS).

From and To Equipment – These specify the connection of pipe between

equipment. In this case, “-“ is removed in the tag name of equipment.

5. MARSHALLING CABINET

XX –000

Example: MC-LIT-104

Marshalling Cabinet - It represents “MC” which stands for Marshalling

Cabinet.

NUMBER

TO EQUIPMENT

FROM EQUIPMENT

MATERIALSIZE

MARSHALLING CABINET NO.

MARSHALLING CABINET




Rev. No. A


Marshalling Cabinet No. - It identifies the number of junction box within the

area.

6. MAIN CABLE

XX – XXX – X – 000: 0 - 0

Example: MC-DJB-A-001:1-1

Main Cable - It represents “MC” which stands for Main Cable.

Junction Box – The place where the main cable is located.

Terminal Block No. – The main cable is terminated in a certain terminal

block no.

Terminal Strip No. - The numerator value of the terminal strip is used.

JUNCTION BOX

MAIN CABLE

TERMINAL BLOCK NO.

TERMINAL STRIP NO.




Rev. No. A


basis of design edit

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