Specification for Power Station - Lankaneth-pawanlankaneth-pawan.com/wp-content/uploads/2016/07/O-12...Specification for Power Station Version 1.0 SP-1118 Page 7 30/06/1999 OP12 Preparation

Specification for Power Station

Specification for Power Station Version 1.0

SP-1118 Page 1 30/06/1999

Authorised For Issue October 2004

Signed : ...........................................................

CFDH, Electrical Engineering

The following is a brief summary of the 4 most recent revisions to this document. Details of all

revisions prior to these are held on file by the issuing department.

Version No. Date Author Scope / Remarks

Version 0 Dec 97 BEB/4 Original issued as ERD-65-04

Version 1.0 June 99 Harith Al Amry,

A/TTE/2

Converted to Specification as per PDO Policy

Cascade & minor changes to the text

Version 2.0 Oct-04 Harith Al Amry,

TTE/5

Minor changes

Version 1.0 Specification for Power Station

30/06/1999 Page 2 SP-1118

Contents

1. Introduction ............................................................................................. 5

1.1 PURPOSE ............................................................................................................ 5

1.2 APPLICABLE STANDARDS, SPECIFICATIONS AND CODES ................... 5 1.2.1 PDO Standards...................................................................................................... 5

1.2.2 SIOP/SIEP Standards ............................................................................................ 7

1.2.3 International Standards ....................................................................................... 11

1.3 COMPLIANCE WITH STANDARDS ............................................................. 12 1.3.1 Language and Units of Measurement .................................................................. 12

1.4 PRODUCT/ASSET WARRANTY ................................................................... 12 1.4.1 PDO System ........................................................................................................ 12

2. Scope ....................................................................................................... 14

2.1 PLANT LAYOUT ............................................................................................. 14 2.1.1 General 14

2.1.2 Plant Orientation ................................................................................................. 14

2.1.3 Equipment Spacing ............................................................................................. 14

2.1.4 Piping and Cable Routing ................................................................................... 15

2.1.5 Hazardous Areas ................................................................................................. 15

2.2 GAS TURBINE GENERATOR AND AUXILIARY EQUIPMENT ............... 15 2.2.1 General Requirements ......................................................................................... 15

2.2.2 Duty and Conditions of Operation ...................................................................... 16

2.2.3 Extent of Supply ................................................................................................. 16

2.2.4 Design and Construction Requirements .............................................................. 16

2.2.5 Pipework and Fittings ......................................................................................... 23

2.2.6 Fire and Gas Detection and Protection Equipment ............................................. 23

2.2.7 Doors .................................................................................................................. 24

2.2.8 Heaters and Ventilators ....................................................................................... 24

2.2.9 Thermal Insulation .............................................................................................. 24

2.2.10 Generator and Excitation System ........................................................................ 25

2.2.11 Wiring and Terminal Boxes ................................................................................ 29

2.2.12 Temperature Classification of Electrical Equipment .......................................... 29

2.3 EMERGENCY DIESEL GENERATING SET ................................................. 30 2.3.1 General ................................................................................................................ 30

2.3.2 Duty .................................................................................................................... 30

2.3.3 Location .............................................................................................................. 30

2.3.4 Diesel Engine ...................................................................................................... 31

2.3.5 Fuel System ......................................................................................................... 31

2.3.6 Generator ............................................................................................................ 32

2.3.7 Controls, Protections and Instrumentation .......................................................... 32

2.3.8 Starting ................................................................................................................ 33

2.3.9 Fire Protection .................................................................................................... 33

2.4 GAS TREATMENT PLANT ............................................................................ 33 2.4.1 General ................................................................................................................ 33

2.4.2 Scope of Supply .................................................................................................. 33

2.4.3 Gas Supply and Analysis .................................................................................... 34

2.4.4 Design Criteria .................................................................................................... 34

2.4.5 Fuel Gas and Condensate Pipelines .................................................................... 34

2.4.6 Gas Treatment Skid ............................................................................................ 34

2.4.7 Water Bath Heater .............................................................................................. 35

2.4.8 Pressure Reducing Station .................................................................................. 35

2.4.9 Fuel Gas Knock Out Vessel ................................................................................ 35

2.4.10 Pipeline Filters .................................................................................................... 36

2.4.11 Filter Separators .................................................................................................. 36


SP-1118 Page 3 30/06/1999

2.4.12 Drains and Condensate Disposal ......................................................................... 36

2.4.13 Pressure Vessels .................................................................................................. 37

2.4.14 Purge Connections and Sampling Points ............................................................. 37

2.4.15 Material Selection ............................................................................................... 37

2.4.16 Emergency and Process Shut-Down (ESD & PSD) Valves ................................ 37

2.4.17 Electrical Equipment Requirements .................................................................... 38

2.4.18 Instrumentation and Control ................................................................................ 39

2.4.19 Vent System ........................................................................................................ 39

2.4.20 Flow Metering and Computation ......................................................................... 39

2.5 INSTRUMENT AIR SYSTEM .......................................................................... 39 2.5.1 Instrument Air Package ....................................................................................... 39

2.5.2 Gas Turbine Generator Air Requirements ........................................................... 40

2.5.3 Instrument Air Distribution Pipework ................................................................. 40

2.6 FIRE ALARM AND PROTECTION SYSTEM ................................................ 40 2.6.1 General ................................................................................................................ 40

2.6.2 Description and Scope of Work .......................................................................... 40

2.6.3 Fire Detectors ...................................................................................................... 41

2.6.4 Combustible Gas Detectors ................................................................................. 41

2.6.5 Manual Break Glass Call Points .......................................................................... 41

2.6.6 Automatic Actions and Alarms ........................................................................... 41

2.6.7 Audible Alarm ..................................................................................................... 42

2.6.8 System Monitor and Alarm Panel ....................................................................... 42

2.6.9 Cabling ................................................................................................................ 42

2.6.10 Fire Protection and Safety ................................................................................... 42

2.6.11 Station Evacuation Alarm ................................................................................... 43

2.6.12 Interfaces with Other Systems ............................................................................. 43

2.7 PAINTING AND SURFACE PROTECTION ................................................... 43 2.7.1 General ................................................................................................................ 43

2.7.2 Control Building and Sunshades ......................................................................... 43

2.7.3 Gas Turbine Generator ........................................................................................ 44

2.7.4 Auxiliary Equipment ........................................................................................... 44

2.7.5 Gas Treatment Plant ............................................................................................ 44

2.7.6 Piping .................................................................................................................. 44

2.8 ELECTRICAL SYSTEM ................................................................................... 44 2.8.1 General Requirements and Philosophy................................................................ 44

2.8.2 Transformers ....................................................................................................... 45

2.8.3 132kV System ..................................................................................................... 46

2.8.4 MV/LV Switchgear ............................................................................................. 46

2.8.5 Electrical Motors ................................................................................................. 47

2.8.6 DC UPS System .................................................................................................. 47

2.8.7 AC UPS Systems ................................................................................................. 48

2.8.8 Relays .................................................................................................................. 48

2.8.9 Cables .................................................................................................................. 49

2.8.10 Earthing and Lightning Protection System .......................................................... 49

2.8.11 Lighting and Small Power System ...................................................................... 50

2.9 INSTRUMENTATION, CONTROL AND MONITORING SYSTEMS .......... 51 2.9.1 General ................................................................................................................ 51

2.9.2 Control and Operation Philosophy ...................................................................... 51

2.9.3 Gas Turbine Generator Instrumentation .............................................................. 53

2.9.4 Generator Control Panel ...................................................................................... 54

2.9.5 Dedicated Remote Control System ..................................................................... 54

2.9.6 SCADA ............................................................................................................... 55

2.9.7 Metering .............................................................................................................. 55

2.10 EMERGENCY SHUTDOWN SYSTEM........................................................... 55 2.10.1 General ................................................................................................................ 55

2.10.2 PSD ..................................................................................................................... 56

2.10.3 ESD ..................................................................................................................... 56

2.10.4 Resetting After A PSD Or ESD .......................................................................... 56


30/06/1999 Page 4 SP-1118

2.11 ENVIRONMENTAL CONSIDERATIONS ..................................................... 56

2.12 CIVIL WORKS ................................................................................................. 56

APPENDICES

APPENDIX 1 : STANDARD DRAWINGS ................................................................................... 57

APPENDIX A : GLOSSARY OF DEFINITIONS, TERMS AND ABBREVIATIONS ................ 58

SP USER-COMMENT FORM ........................................................................................................ 60


SP-1118 Page 5 30/06/1999

1. Introduction

1.1 PURPOSE

Design engineering, supply, installation, testing and commissioning of Gas Turbine Power

Stations in the range of 25MW to 60 MW in PDO system shall be governed by this SP. The

Power Station shall be governed by, but not limited to, the provisions specified, and shall be

undertaken to the highest standards of engineering, material supply and workmanship to give

the most reliable system. For any specific application additional information and data will be

necessary to define the particular requirement for that case.

This Standard shall be utilised with one or more of the referenced SPs and international

standards to complete the PDO requirement.

1.2 APPLICABLE STANDARDS, SPECIFICATIONS AND CODES

The following Standards, specifications and codes should be consulted when applying the

requirement of this Standard. All listed documents shall be latest issue except those

documents prescribed by date.

1.2.1 PDO Standards

Doc no. Title Disc

07-01 Code of practice for Inspection of Static Equipment Mech

07-02 Methods for NDE Mech

08-01 Pressure Relieving System Process

08-06 Flare and Vent Systems Process

08-10 Drain Systems Process

08-11 Isolation of Process Equipment Process

09-03 Layout of Plant Equipment and Facilities Process

10-15 Supervisory Control & Data Acquisition System(SCADA) Inst

11-01 Civil and Building Standard Drawings Civil

11-02 Site Selection & Soil Investigation Manual Civil

11-03 Guide to Civil Engineering Materials Testing Civil

17-01 (A-T) Civil and Building Construction Specifications Civil

17-02 (A-F) Building Services Construction Specifications Civil

17-04 Civil and Building Design Criteria Manual Civil

17-08 Guide to Safe Road Works Civil

19-07 Civil and Building Guide to Concrete Construction Civil

28-03 Application/Selection of Standard Pipe Supports Mech

28-04 Standard Drawings & Standard Sunshades Civil

29-11 Instrument Air Compressor Package Mech

30-01 Instrument Engineering Design Standards Inst

30-03 Instrumentation Standard Drawings Inst

30-04 Standard Control Building (amend/suppl. to DEP

31.76.10.10)

Civil

30-05 Instrumentation for Equipment Packages Inst


30/06/1999 Page 6 SP-1118

43-01 Welding of on-plot pipework Mech

43-05 Colour Coding of On-plot Pipework Process

43-06 Specification for welding of claa-2 pipelines (Flowlines) Mech

48-01 Painting and Coating Systems Mech

48-06 Surface Preparation & Protective Coating of Oil and Gas

Facilities

Mech

49-01 Corrosion Control Procedures Mech

50-02 Cathodic Protection Standard Drawings Elec

63-01 Electrical Installation Practice Elec

64-01 Amendment/Supplement to DEP 33.64.10.10 Elec

64-04 Electrical Standard Drawings Elec

64-06 Electrical Protection Systems Elec

64-07 (10-18) Electrical Identification of Underground cables & other

standards

Elec

64-07 (23 / SI) Ops Restr. on Holec Capitole 3 & 3N low voltage

switchboards

Elec

64-09 Earthing and Bonding Elec

65-01 Construction of Cathodic Protection Systems Elec

65-02 Cathodic Protection Materials and Equipment Specifications Elec


65-12 Design of Cathodic Protection Systems Elec




71-01 Installation of Telephone Cable Network Elec

80-01 Inspection of lifting equipment Mech

84-01 Precommissioning, Flushing etc. Mech

88-02 Fire & Gas Detection and Protection Safety

88-03 Guide to SAFOP on Electrical System Elec

88-05 Safe working Proc. On Cathodically Protected Structures Elec

97-01 Operation of Cosasco Retrieving Equipment Mech

EPG-01 PDO Emergency Procedures Guide - Part 1, Corporate Plan Gen

EPG-02 PDO Emergency Procedures Guide - Part 2, Quick Response

Guide

Gen

EPG-03 PDO Emergency Procedures Guide - Part 3, Vol. 1 Safety

Serv. Function

Gen

OP02 Use and Storage of Flare Cartridges Gen

OP06 Testing of Protection Relays on the Electrical Systems Gen

OP07 Testing of Instrument Safeguarding Systems Gen

OP08 Flow Factor Updating Gen

OP09 Operator Routine Functions Gen

OP10 Work Practice & Regulation References Gen


SP-1118 Page 7 30/06/1999

OP12 Preparation of Tanks & Vessels for Internal Work Gen

OP13 Locking Practice at Unattended Stations Gen

OP15 Safeguarding Systems & Equipment Testing Gen

OP17 Gas Testing Gen

OP18 Use and Handling of Chemicals Gen

OP19 Pressure Relief Valve Isolation/locking Procedure Gen

OP20 Overtime Procedures Gen

OP23 Removal of Sweet or Sour Instruments Gen

SI06 Testing Operations Safeguarding Systems Gen

SI07 Electrical Protective Systems Gen

SI09 Operations Asset Management Gen

SI14 Operations Procedure Variance (Temporary) Gen

SI16 Disposal of Chemical Wastes Gen

SI23 Change of Alarm Settings Gen

SI24 Inspection/ Overhaul of Static Equipment Gen

SI26 Isolation of Process Equipment Gen

SI28 Locked Value Control Procedure Gen

SRD/G/03 Guidelines for Hazard Management Gen

SRD/S/02 Fire Extinguishers Gen

SRD/S/03 Guidance and Standards for Personal H2S Monitor Gen

TCC/006/92 Network User Guide Gen

WP01 Ops & Maintenance of a Daniel Senior Orifice Fitting Gen

WP06 Iron Sulphide (FeS) Removal From Process Equipment Gen

WP14 Commissioning - Instrument Air Packages Gen

WP17 Commissioning - Relief & Flare Systems Gen

WP20 Timekeeping in the Interior Gen

1.2.2 SIOP/SIEP Standards

Doc no. Title Disc.

00.00.05.05 Index to DEP publications and standard specifications Gen

00.00.06.06 Index to standard drawings Gen

00.00.10.05 Standard forms (binder) Gen

00.00.20.10 The use of SI quantities and units (Endorsement of ISO 31

and ISO 1000)

Gen

01.00.01.30 Definition and determination of temperature and pressure

levels

Process

01.00.02.12 Preparation of safeguarding memoranda and process

safeguarding flow schemes

Process

20.21.00.31 Fouling resistance for heat transfer equipment Process

30.10.02.11 Metallic materials - Selected standards Mech

30.10.02.13 Non-metallic materials - Selection and application Mech


30/06/1999 Page 8 SP-1118

30.10.02.31 Metallic materials for use in less than 45 deg or lethal

substances Mech

30.10.60.18 Welding of metals Mech

30.10.60.22 Welding and inspection requirements for equipment not

covered by recognised standards and/or codes

Mech

30.10.73.10 Cathodic protection Mech

30.10.73.31 Design of Cathodic protection systems for onshore buried

pipelines

Elec

30.46.00.31 Thermal insulation for hot services Mech

30.46.00.32 Thermal insulation for cold and dual-temperature services Mech

30.48.00.31 Painting and coating for new equipment Mech

30.48.40.31 Int. Alu-Zinc Spray of Tanks and vessels Mech

30.48.41.31 Electroless nickel plating (Amendments/Supplements to

ASTM B 733)

Mech

31.10.00.31 Noise control Mech

31.10.03.10 Symbols and identification system – Mechanical Mech

31.21.01.30 Shell-and-tube heat exchangers (Amendments/Supplements

to TEMA standards)

Mech

31.21.01.31 Selected construction materials for shell-and-tube heat

exchangers

Mech

31.21.70.31 Air-cooled heat exchange equipment

(Amendments/Supplements to API Std 661)

Mech

31.22.05.11 Gas/liquid separators - Type selection and design rules Process

31.22.10.32 Pressure vessels (Amendments/Supplements to BS 5500) Mech

31.22.10.35 Manufacturing report for pressure vessels Mech

31.22.20.31 Pressure vessels (Amendments/Supplements to ASME

Section VIII )

Mech

31.24.00.30 Fired heaters, including waste heat boilers

(Amendments/Supplements to API 560)

Mech

31.25.00.10 Guide for the selection of hoisting facilities and weather

protection for rotating equipment

Mech

31.29.00.10 Installation of rotating equipment Mech

31.29.00.32 Special purpose gear units for petroleum, chemical and gas

industry services (Amendments/Supplements to API STD

613)

Mech

31.29.02.11 Pumps – Selection, testing and installation Mech

31.29.02.30 Centrifugal pumps (Amendments/Supplements to API Std

610)

Mech

31.29.12.30 Reciprocating positive displacement pumps and metering

pumps (Amendments/Supplements to API Std 674 and API

Std 675)

Mech

31.29.40.32 Rotary-type positive displacement compressors

(Amendments/Supplements to API Std 619)

Mech

31.29.40.33 Packaged, integrally geared, centrifugal plant and instrument

air compressors (Amendments/Supplements to API Std 672)

Mech

31.29.47.30 Centrifugal fans Mech


SP-1118 Page 9 30/06/1999

31.29.60.32 Lubrication, shaft-sealing and control oil systems for special-

purpose application (Amendments/Supplements to API Std

614)

Mech

31.29.70.31 Combustion Gas Turbines (Amendments to API 616) Mech

31.29.80.30 Diesel fuelled compression ignition engines Mech

31.36.10.30 Hydraulic systems for operation of valves Mech

31.37.00.11 Instrument air supply Inst

31.38.01.10 Piping classes – Basis of Design Mech

31.38.01.11 Piping - General requirements Mech

31.38.01.21 Specification for piping systems Mech

31.38.01.29 Pipe supports Mech

31.38.01.31 Shop and field fabrication of steel piping Mech

31.38.60.10 Hot-tapping on pipelines, piping and equipment Mech

31.40.10.14 Pipeline overpressure protection Process

31.40.60.11 Pipeline leak detection Inst

31.46.00.31 Acoustic insulation for pipes, valves and fittings Mech

31.76.10.10 Heating, ventilation and air conditioning for plant buildings Mech.

31.76.10.11 Installation, testing and balancing, and commissioning of

HVAC systems

Mech

32.10.03.10 Symbols and identification system - Instrumentation. Part 1:

- Process (engineering) flow schemes

Inst


- Functional logic diagrams

Inst


- Instrumentation loop diagrams

Inst

32.30.10.30 System cabinets Inst

32.30.20.11 Instrumentation for Fire, gas and smoke detection systems Inst

32.31.00.10 Instrument engineering procedures Inst

32.31.00.32 Instruments for measurement and control Inst

32.31.09.31 Instrumentation for equipment packages Inst

32.32.00.11 Turbine fiscal metering systems for liquid hydrocarbon Inst

32.32.10.10 Flow instruments Inst

32.36.01.16 Sizing of control valves Inst

32.36.01.17 Control valves: Selection and specification Inst

32.37.00.33 Mounting of plant instruments Inst

32.37.10.11 Instrument impulse lines Inst

32.37.20.10 Instrument signal lines Inst

32.37.20.31 System cabling Inst

32.37.51.11 Instrument air lines Inst

32.45.10.10 Instrumentation of depressurising systems Inst

32.71.00.10 Plant telecommunication Telecom

32.71.00.11 Telecommunication standards Telecom

32.71.00.30 Structured cabling systems for telecommunications Telecom


30/06/1999 Page 10 SP-1118

32.80.10.10 Classification and implementation of instrumented protective

functions

Inst

33.10.03.10 Symbols and identification system - Electrical Elec

33.64.10.10 Electrical engineering guidelines Elec

33.65.11.31 Synchronous AC generators 1250 kVA and above Elec

33.65.11.32 Packaged unit AC generator sets Elec

33.65.40.31 Power transformers (Amendments/Supplements to IEC 76

and IEC

Elec

33.65.50.31 Static DC uninterruptible power supply unit (Static DC UPS

unit)

Elec

33.65.50.32 Static AC uninterruptible power supply unit (Static AC UPS

unit)

Elec

33.66.05.31 Electric motors - Cage-induction and synchronous type Elec

33.66.05.33 Electrical variable speed drive systems Elec

33.67.01.31 Low-voltage switchgear and controlgear assemblies

(Amendments/Supplements to IEC 439-1)

Elec

33.67.51.31 High-voltage switchgear and controlgear assembles

(Amendments/Supplements to IEC 298)

Elec

33.68.30.32 Electrical trace heating Elec

34.00.01.30 Minimum requirements for structural design and engineering Civil

34.11.00.10 Site investigations Civil

34.11.00.11 Site preparation and earthworks Civil

34.11.00.12 Geotechnical and foundation engineering Civil

34.13.20.31 Roads, paving, surfacing, slope protection and fencing Civil

34.14.20.31 Drainage and primary treatment facilities Civil

34.17.00.32 Minimum requirements for design and engineering of

buildings

Civil

34.17.10.30 Reinforced control buildings/Field auxiliary rooms Civil

34.18.51.10 Minimum requirements for the construction and maintenance

of tank foundations, bund walls and drainage systems for

small storage installations

Civil

34.19.20.11 Fire hazards and fireproofing/cold splash protection of steel

structures

Civil

34.19.20.31 Reinforced concrete foundations and structures Civil

34.24.26.31 Steel stacks (Amendments/Supplements to CICIND Model

Code)

Civil

34.28.00.31 Steel structures Civil

44.24.90.31 Refractory bricks and shapes Mech

61.10.08.11 Field inspection prior to commissioning of mechanical

equipment

Mech

61.38.10.10 Shop and field fabrication of orifice meter runs Mech

61.40.20.30 Welding of pipelines and related

facilities(Amendments/Supplements to ANSI/API)

Mech

62.10.08.11 Field inspection and testing of instruments and instrument

systems

Inst


SP-1118 Page 11 30/06/1999

62.10.09.11 Factory inspection and testing of instruments and instrument

systems

Inst

62.37.10.12 Instrument installation procedures Inst

63.10.08.11 Field commissioning and maintenance of electrical

installations and equipment

Elec

64.24.32.30 Insulating and dense refractory concrete linings Mech

70.08.10.10 Equipment and tools for maintenance and inspection. Part 1:

Inspection - Tools and NDT instruments

Mech


- Mechanical maintenance - Equipment, tools and bolt

tensioning

Mech


- Electrical workshop - Test equipment and tools

Mech

70.08.10.14 Equipment and tools for maintenance and inspection. Part 5:-

Instrument technical centre and workshop - Equipment and

tools

Mech

70.10.70.11 The preservation of old and new equipment and piping

standing idle

Mech

70.10.80.11 Cleaning of equipment Mech

70.10.90.11 Spare parts Mech

80.00.10.10 Area classification (amendments/supplements to IP 15) Process

80.45.10.10 Pressure relief and flare system Process

80.46.30.11 Interlocking systems for safety/relief valves Mech

80.47.10.10 Fire-fighting agents Safety

80.47.10.30 Assessment of the fire safety of onshore installations Safety

80.47.10.31 Active fire protection systems and equipment for onshore

facilities

Safety

80.47.10.32 Portable and mobile equipment for fire-fighting Safety

A-4-1 Fuel systems Mech

L-5-1/2/3 External fusion-bonded epoxy powder coating for line pipe Mech

W-5-1/2/3 Repair by welding of aluminium and aluminium-alloy

castings

Mech

W-6-1/2/3 Equipment made of 2.25 Cr - 1 Mo steel in quenched and

tempered condition

Mech

W-7-1/2/3 Aluminium-bronze sand castings (Amendments/Supplements

to ASTM B 148)

Mech

T.2.238.761 Integrated motor control system Elec

EP 92-0980 Guidelines for Manual Sampling and Analysis of

Hydrocarbon Fluids

Process

ERD

1.2.3 International Standards

All relevant international standards as referred to in the individual DEP/SP shall be

applicable.


30/06/1999 Page 12 SP-1118

1.3 COMPLIANCE WITH STANDARDS

All requirements of this Specification shall apply except where equipment manufacturer's

standards are more stringent, then the latter shall apply.

The user shall obtain the written approval from the technical authority within PDO for any

deviations from this Specification. The appropriate technical authorities are set out in ERD-

00-02.

In all cases the Company shall determine the adequacy of Works executed by the Contractor

in accordance with this Specification.

1.3.1 Language and Units of Measurement

The English language and the SI system of units shall be used through out for all the

documentation and drawings. Where necessary for a specific application, alternative units

may be indicated in brackets behind the SI units.

1.4 PRODUCT/ASSET WARRANTY

The entire power station package and all individual equipment forming part of it shall be

guaranteed to meet specified technical particulars listed in this Specification and all referred

standards and codes. It shall have an expected technical lifetime of at least 20 years.

Clarification to how this requirement will be met shall be provided in the quotation, in

particular giving attention to the redundancy and availability of spare parts.

If the guaranteed performance of the power station and all equipment forming part of it is

not met and/or if any equipment fails to comply with the specification requirement in any

respect whatsoever at any stage of manufacture, test or erection, the Company 's

Representative may reject the package, or defective equipment thereof, whichever he

considers necessary, and after adjustment or modification as directed by the Company's

Representative, the Contractor shall conduct further inspection and/or test.

All repair procedures shall not be performed without the prior approval of the Company's

Representative. In the event of a defect on any equipment/component being of such a nature

that the specification requirements cannot be fulfilled by adjustment or modification, such

item shall be replaced by the Contractor, at his own expense to the entire satisfaction of the

Company's Representative. Any equipment/component of the power station package repaired

to an approved procedure shall not be accepted as a part of the Works as a permanent

solution or replacement unless the Contractor guarantees in writing that the repaired

equipment shall have the same service lifetime and efficiency as the equipment/ component

originally manufactured.

The Contractor shall also warrant all equipment and component parts forming the power

station package against defective material, design and /or workmanship. Contractor shall

assume single point of responsibility for equipment warranty and performance guarantee for

all equipment forming this power station package.

The approval of the Company's Representative of inspection and/or test results will not

prejudice the right of the Company's Representative to reject whole or part of the package if

it does not comply with the contract document when erected or prove completely satisfactory

in service.

Product/asset warranty shall further refer to the requirement as specified in the commercial

package of the contract document.

1.4.1 PDO System

PDO electrical system is one electrical network covering the operational areas of PDO in

north and south Oman. North Oman and South Oman electrical systems are interconnected

with a single 132kV overhead line. Refer to the single line diagrams EFD 4 0252 001 E1

and EFD 4 0252 002 E1 for the North Oman and South Oman systems respectively.


SP-1118 Page 13 30/06/1999

The electrical system consists of Gas Turbine generators stations (maximum generator set

size of 30 MW at approximately 50C (Frame - 6)), interconnected with a 132kV electrical

transmission network and a distribution electrical network of 33kV.

The Generating stations are unattended and are remotely controlled from the Dedicated

Remote Control System located at Yibal using GE’s SMART REMOTE system for North

Oman and using DMACS control system for South Oman. SCADA Master Control Centres

located at Yibal and slave Control Centre at Marmul act as a standby system for the

Dedicated Remote Control Systems. However, the requirement is now to have all North and

South Power Stations controlled from Yibal Central Control Room.


30/06/1999 Page 14 SP-1118

2. Scope

2.1 PLANT LAYOUT

2.1.1 General

The Gas Turbine Power Station shall be designed for accommodating upto three numbers

Gas Turbines of the specified capacity. All the common facilities and plant layout shall be

designed for the ultimate configuration of three units, unless stated otherwise..

The plant configuration of simple cycle Frame 6 power plants is well established in PDO.

The enclosed plant layout Drg. STD-3-1800-001 shows a typical 3 x 30 MW plant

configuration. As PDO have yet to install gas turbine units larger than 30 MW there are no

existing design references but in principle the plant layout requirements will be similar to the

smaller 30 MW units. The larger 60 MW gas turbines may have additional off base

auxiliaries compared to the smaller unit.

Gas turbine units shall be installed parallel to each other, except when the proposed site is

suitable only for gas turbine generators placed in line.

2.1.2 Plant Orientation

The power plant is divided into four distinct areas

Gas supply, treatment and venting

Gas turbine generators

Control building and station auxiliaries

Electrical export

The typical layout drawing STD-3-1800-001 shall be referred for the locations for the site

utilities such as water, air, fuel and oil.

The content of these areas will be to some extent project specific as gas treatment

requirements and electrical interconnection will vary from project to project. The orientation

will be developed to suit the dimensions of the land available, direction of incoming gas

supplies and best route for electrical export, wind direction, location of existing facilities

with respect to the Power Plant site.

The gas treatment plant and electrical equipment shall not be situated besides each other.

The preferred orientation is with the gas treatment facilities on one side of the gas turbines

and the electrical and control systems on the other side. This arrangement simplifies the

plant layout and minimises common areas.

The control building shall be a minimum of 15 metres from the Power Island consisting of

the Gas turbine, generator and the generator transformer.

The vent area shall be located to suit prevailing wind conditions and to minimise the risk of

any release from the vent blowing towards the power plant or adjacent facilities.

The emergency diesel generator, if specified in the Project specifications, shall be positioned

adjacent to the control room, but no nearer than 15 metres to the building. The emergency

generator and the station instrument air package can be located under a common sunshade.

The sunshade shall include an additional covered area for storage.

2.1.3 Equipment Spacing

The plant spacing should generally be in compliance with ERD 09-03. The gas turbine

generator, generator transformer, control compartment and off base auxiliaries are

considered as one Module.


SP-1118 Page 15 30/06/1999

The minimum distance between 30 MW gas turbine centre lines is 30 metres. The minimum

gas turbine spacing for sites which will have Waste Heat Recovery Units (WHRUs) or plan

to have WHRUs in the future shall be 65 metres between gas turbine centre lines, based on

the WHRU being positioned at 90 degrees to the gas turbine axis. This spacing could be

reduced if small WHRUs are to be installed or the WHRU is placed in parallel to the gas

turbine.

For larger gas turbines with cold-end drive with provision for WHRUS, the WHRU shall be

placed on the same centreline as the gas turbine.

The gas treatment plant for a single gas turbine unit may consist of several skid mounted

packages but shall be considered as one HP Module. The distance between unit modules

shall be 30 metres.

The vent stack area shall normally be 40 metres by 40 metres. If the radiation of the ignited

vent or gas dispersal calculations indicate a larger area requirement the height of the stack

shall be increased in the first instance up to a maximum vent height of 30 metres. Only if the

increase in stack height does not provide a solution should the vent sterile area be increased.

2.1.4 Piping and Cable Routing

2.1.4.1 Piping

Piping in the gas treatment plant and vent stack area shall be located above ground.

Pipework around the gas turbine area should be buried to provide clear access for

maintenance.

2.1.4.2 Cabling

The cabling around the gas turbine and between the adjacent gas turbine auxiliaries shall be

placed in concrete trenches with concrete covers. Cabling between the gas turbine and the

control room may be direct buried.

2.1.5 Hazardous Areas

All the equipment in the gas treatment plant and vent stack areas are to be considered as a

Zone 2 Hazardous area in accordance with IP 15. The gas turbine gas compartment/module

vent shall be considered as a Zone 2 hazardous area. The exact gas and temperature

groupings shall be to match the gas composition available for the individual project.

2.2 GAS TURBINE GENERATOR AND AUXILIARY EQUIPMENT

2.2.1 General Requirements

The gas turbine generator unit shall be supplied complete with all auxiliary equipment

necessary for its safe and efficient operation with the specified fuel and shall be designed for

outdoor installation in a packaged enclosure suitable for the specified climatic conditions.

The unit shall be capable of continuous operation. The gas turbine shall be of the heavy duty

Industrial type to the manufacturers latest standard

Unless otherwise specified the gas turbine shall be designed to fire natural gas using a single

combustion system.


30/06/1999 Page 16 SP-1118

2.2.2 Duty and Conditions of Operation

The power station will be required to operate satisfactorily at any load up to its peak load

rating in parallel with the existing electrical system under any ambient or climatic conditions,

which may occur.

The site base load rating shall be the equivalent of the ISO standard base load rating as

defined in ISO 3977 Section 7.3.

The unit shall have the capability to operate for limited periods of time at a peak rating equal

to at least 110% of the base load rating.

2.2.3 Extent of Supply

The gas turbine unit shall be complete with all equipment and accessories necessary for the

safe, efficient and reliable operation of the plant including but not necessarily limited to the

following:

Skid mounted, packaged gas turbine and generator, complete with auxiliaries, gearbox,

driven coupling etc.

Starting system

Barring gear

Lubricating oil system which shall provide the lubrication requirements for the gas

turbine, gearbox and generator, complete with all pumps, filters, coolers, controls etc.

Fuel system for operation on the specified fuel complete with all ancillary equipment

and controls.

Inlet air system complete with self cleaning filtration system, silencer, ducting, trash

screens, plenum and all necessary ancillary equipment and controls. A similar system for

alternator cooling air shall be provided.

A mist eliminator shall be installed in the inlet air system.

Complete ancillary cooling systems

Offline Compressor blade cleaning equipment for inter-connection to water wash skid.

All interconnecting pipework, valves, drains, vents and supports for all equipment.

Acoustic and thermal insulation

Interconnecting cabling and switchgear

Separate Microprocessor based control and machine monitoring system.

Fire and gas detection system

Special tools and cleaning equipment

2.2.4 Design and Construction Requirements

2.2.4.1 General

The design of the gas turbine and all auxiliary equipment shall have been fully proven by

extensive successful operation in commercial service.

The gas turbine generator unit shall be designed to ensure that the base load continuous

operating period between major overhauls is not less than 72000 hours, combustion

inspection every 12000 hours,hot gas path inspection every 36000 hours when operating on

the specified fuel and under the specified climatic conditions. This figure may be modified

by an agreed formula to take account of peak load operation and number of starts. Formula


SP-1118 Page 17 30/06/1999

to determine the number of equivalent base load hours to take into consideration peak fired

hours and the number of starts shall be submitted.

2.2.4.2 Hazardous Area Classification

The areas adjacent to the gas turbine and fuel system shall be given a hazardous area

designation according to the requirements of IP 15 taking into account the nature of the fuel.

Only one flanged connection adjacent to the gas turbine for hydrocarbon services is

permitted. Other flange connections for temporary filters, etc. shall be located adjacent to

the fuel gas treatment plant.

2.2.4.3 Package Enclosures

The Gas turbine Generator unit shall be of the packaged type suitable for outdoor installation

in the specified site climatic conditions. The gas turbine generator enclosure shall be

fire/explosion protected and consist of several interconnected compartments forming a

weather protective housing constructed of steel and structurally attached to each

compartment base. Each enclosure compartment shall provide thermal insulation, acoustical

attenuation and fire extinguishing media containment. Each compartment shall be designed

to provide adequate access for operation and maintenance purposes and for easy removal of

all major items of equipment.

The Generator and exciter shall be housed in a single acoustic enclosure allowing free access

to all parts of the equipment.

Each enclosure compartment shall be provided with fluorescent lighting and adequate

number of switched socket outlets to facilitate the use of power tools and inspection

equipment during maintenance and overhaul operations.

2.2.4.4 Compressor

The Compressor shall be designed to operate at speed corresponding to system frequencies

of 47.5 Hz to 52.5Hz with sufficient margin from its surge line characteristic such that it is

unconditionally stable at all conditions of load and ambient temperature and to allow for

reasonable amounts of blade fouling. Provision shall be made for accurately measuring

mean compressor delivery temperature and static delivery pressure.

The variable inlet guide vanes shall be supplied to the latest material specification.

2.2.4.5 Combustion System

Combustion efficiency shall be sufficiently high to ensure a colourless exhaust. A dry low

NOX combustion system shall be provided capable of achieving NOX and CO emissions of

25 ppm and 15 ppm respectively, at full load.

2.2.4.6 Skid

The skids for the gas turbine and generator shall be of substantial continuously welded

construction and have floor plate covering the top surface with cut-outs for supports.

The primary members shall be adequately crossbraced to prevent flexing or distortion of skid

during transporting and installation. Equipment mounted on the skid shall not be considered

as bracing the skid.

Minimum metal thickness at point of equipment bolting shall be 10 mm.

Pad-eye or equal lifting lugs, designed for minimum load factor of 2.0, for lifting sling

attachments and one point pickup using spreader beams, shall be attached to facilitate

loading and unloading.

Each skid unit shall be stiff enough to absorb loads experienced during lifting and transit

over unmade roads without permanent deformation and without damage occurring to any

component part of the package. Skids shall have shock recorders installed to monitor transit

loading shocks.

Each skid shall be provided with two earth connection points for connecting to the main

station earthing system. All non-current carrying metalwork on the skid, which is not


30/06/1999 Page 18 SP-1118

permanently welded, to the skid base shall be bonded to the base using adequately sized

earth cables.

2.2.4.7 Unit Fuel System

The acceptable limits for variations in the physical properties and constituents, which are

consistent with satisfactory operation of the gas turbine up to its maximum peak load rating,

shall be defined by the manufacturer. In particular, the maximum acceptable levels of

sulphur and metallic compounds, or combinations of these compounds, in the fuel delivered

to the fuel nozzles shall be defined. Analysis of samples of the specified fuel to confirm its

suitability for satisfactory operation of the gas turbine shall be carried out by the supplier.

The fuel control system shall be capable of providing speed control for manual and

automatic synchronising purposes such that the generator frequency can be varied and

maintained within + 0.5% between 45 Hz (full load) and 52 Hz (no load) with a nominal 4%

full load droop.

2.2.4.8 Ventilation and Air Conditioning

The GT unit auxiliary control cabin shall be environmentally controlled by means of 2 x

100% capacity, heavy duty air conditioning systems supplied by PDO approved vendors,

designed to maintain a dry bulb temperature within the range 22ºC to 25ºC and a relative

humidity between 45% and 55% under all ambient conditions. The design of the equipment

shall take into account the maximum heat load from all sources particularly solar gain,

personnel occupancy, lighting and any other heat releasing media.

The Gas turbine-generator enclosure shall be provided with a forced ventilation system

designed to:

Remove sufficient heat at the maximum ambient temperatures specified, to provide an

acceptable internal environment for all equipment installed inside the compartment,

without the need to reduce the output when one fan is running.

Dilute the concentration of any gas leaking from equipment.

The accessory and turbine compartments shall be ventilated by means of 2 x 100% fans (one

operating and one standby) taking suction from the main air inlet duct to the gas turbine

(filtered air). Each fan shall be able to be selected for operating or standby mode manually.

Each fan shall be provided with a outlet damper and differential pressure measurement,

which shall automatically start the standby fan on failure of the operating fan (low

differential pressure). The ventilation and other equipment mounted on the roof of the gas

turbine package shall be accessible by stairs and walkways.

The generator and load gear compartments shall be ventilated by the generator cooling air.

Special attention to reduce the temperature inside the load gear compartment shall be given.

Options to be considered are the use of a back to front flow pattern or a modified barrier wall

on the turbine exhaust side.

2.2.4.9 Turbine

The turbine casings, ducting and moving and stationary blading shall be designed to

withstand the maximum temperature scatter which may occur in service under adverse

combustion conditions, with the machine running at the design maximum mean turbine inlet

temperature. The casings, blading and ducts shall withstand, without premature failure, the

thermal shock associated with repeated starting and loading.

If bolts are to be tightened under heat or by extension by hydraulic or mechanic means, one

full set of the necessary equipment shall be supplied.

Hot gas path inspection shall be possible via suitable plugged openings to introduce

borescope-type equipment

All instrumentation required to measure gas turbine exhaust temperatures shall be provided

and this shall show any imbalance in the temperature distribution in relation to the first stage

blades.

2.2.4.10 Governor


SP-1118 Page 19 30/06/1999

A solid state electro/hydraulic or mechanical/hydraulic speed sensing governor shall be

provided which is capable of stable control of the ac generator frequency, when operating as

an independent unit, and of the fuel energy input to the turbine and AC generator load when

operating in parallel with an existing supply system, in accordance with ISO.3977.

The Governor controls shall have facility for selection of automatic change over between

peak load mode and base load mode, when the GT experiences a sudden load change.

The governor shall be capable of control in either of the pre-selected mode namely., speed

droop or isochronous mode. The speed droop characteristic shall be adjustable on site from

0% to 10% in increments no greater than 0.5% but shall not be directly accessible to the unit

operator. The control range of speed control loop shall have a no load speed adjustment

from 96% of rated speed to an upper limit compatible with the above specified range of

speed droop characteristic.

The means for adjustment of the speed control shall be provided both on the Generator

control panel, SCADA system and on the Dedicated Remote Control system. Means shall

also be provided on the Unit Control Panel to manually override the governor and/or speed

control so that controlled no load testing of the overspeed trips can be made.

Upon an instantaneous full load rejection, the governor and associated control equipment

shall maintain the transient speed of the unit within acceptable limits, at least 2% below the

overspeed trip point when operating within its design capability.

The control systems shall be capable of retarding the rate of load acceptance to within

permissible limits, irrespective of any action on the part of the operator.

2.2.4.11 Overspeed Trips

Duplicate overspeed trips shall be provided which will shut down the machine in the event of

overspeed exceeding 10%.

Both trips are to sense shaft speed and either shall cause the fuel supply to be cut off by an

independent method.

The means of cutting off the fuel supply shall be fail-safe, i.e. depressurising a hydraulic

signal or, if not entirely mechanical in action by de-energising electrical devices not vice

versa.

2.2.4.12 Dynamics and Shaft Assembly

i) General

The vibration equipment shall be selected from the PDO’s approved vendor list or include

the manufacturers standard system and this shall be used for protection of the train. In

addition, displacement probes and key phasor shall be installed for condition monitoring and

alarm purposes. Galvanic isolators shall be in accordance with ERD-30-01. The vibration

limits specified below are mandatory:

ii) Factory tests

At all times after run-up until shut-down (i.e. 100% operating speed including warm-up and

cool-down), the vibration level shall not exceed 5 mm/s peak to peak.

iii) Field tests

The performance testing of the GTG shall be carried out at peak, full and half loads in

accordance with ISO 3977.

Load acceptance and load rejection tests for 100% load shall be carried out, when possible.

Gas samples shall be tested by an independent body.

At all times after run-up until shut-down (i.e. 100% operating speed including warm-up and

cool-down), the vibration level shall not exceed 6.4 mm/s 0-peak, except during the warm-up

period where a peak level of 8 mm/s 0-peak is acceptable.

Balancing in the field to achieve the above vibration levels is not acceptable.

A full vibration signature, which includes frequency analysis, run-up/shut-down, bode plots,

run out and orbit measurements shall be made during the factory tests.


30/06/1999 Page 20 SP-1118

A full report of lateral and torsional dynamic behaviour is to be prepared and submitted,

including model applied to verify bearing wear behaviour, overhang weight influences etc.

iv) Lateral Critical Speed

The first and second critical speeds shall be at least 10 percent below or 20 percent above the

operating speed range.

The critical speed below 105 percent of operating speed shall be determined during a

mechanical running test if it has not been established by previous tests.

v) Torsional Critical Speeds

No torsional critical speed shall be within less than 10 percent of the first or second harmonic

of the rotational frequency in the operating speed range.

No torsional critical speeds shall be within 10 percent of load-gear tooth-passing frequencies

within the operating speed range, except where a node exists at this gear teeth.

The system of turbine, load gear and generator with base plate, anchor bolts and foundations

shall be checked for sensitivity and shall be stable for a three-phase short-circuit effect.

vi) Vibration and Balance

Individual shafts, discs and couplings shall be dynamically balanced before assembly so that

the security of vibration of the complete unit during operation does not exceed the specified

margins.

2.2.4.13 Main Load Gearbox and Auxiliary Geared Drive

The main load gearbox and auxiliary geared drive shall be of proven design and specifically

designed for continuous operation. A sump type gearbox is preferred.

The main gearbox shall be capable of transmitting the maximum power developed by the gas

turbine under any condition of operation and also to withstand the short circuit torque and

the maximum torque generated by the alternator during faulty synchronisation. It shall also

be capable of withstanding 20% overspeed for 5 minutes.

Service factor for gearing shall not be less than 1.5. Gearbox design shall be in accordance

with AGMA 420 and 421, as applicable.

All high speed gears shall be provided with hydro-dynamic white metal journal and thrust

bearings, which together with the gear teeth shall be lubricated from the gas turbine

lubricating oil system. The complete kinematic chain, including all couplings, shall be

dynamically balanced.

All gearing shall be totally enclosed in a fabricated steel housing, dust and oil proof,

horizontally split to allow easy inspection of all internal components without breaking the

alignment. All casing mating steel surfaces shall be "stone ground" to ensure that no oil

leakages occur during operation.

2.2.4.14 Couplings

Couplings shall be of a type not requiring routine maintenance or inspection between periods

of major overhaul.

Couplings of an all metal flexible element design are preferred.

The couplings shall be designed to withstand, without damage, the torque that would be

imposed upon them during generator short circuit conditions.

2.2.4.15 Compressor Cleaning Equipment

To prevent build-up of deposits on the compressor blading a permanently installed off-load

compressor washing system shall be provided such that the compressor can be efficiently

cleaned without the necessity for opening up or dismantling any part of the machine.

The Compressor bellmouth shall be fitted with a ring pipe manifold and nozzles for injection

of the water/detergent mixture while the machine is cold cranked. Isolating valves shall be

provided on the cooling and sealing air lines to ensure that the effluent is directed to the

casing drains.


SP-1118 Page 21 30/06/1999

A compressor washing skid shall be supplied which shall include the following:

Galvanised steel water storage vessel complete with motor driven pump, electric

immersion heater, level gauge, temperature and level switches.

All necessary valves and interconnecting piping

All necessary controls and instrumentation

Structural steel base

All equipment necessary for the storage and handling of the cleaning agent shall be provided

including suitable water storage facilities on the site.

2.2.4.16 Rotor Turning Device

A rotor turning device consisting of an electro-hydraulic ratchet system, supplied by a DC

driven pump and torque converter, shall be provided to turn the shaft during the cool down

period.

2.2.4.17 Starting System

i) General

It shall be possible to run the gas turbine continuously in the unfired condition for

compressor cleaning purposes.

The gas turbine start-up sequence shall be automatic in operation.

ii) Diesel Engine or Electro-Hydraulic Starting

The starting of the gas turbine shall be either by means of diesel engine or electro-hydraulic

starting as specified in the individual project specifications.

Where diesel engine is specified, the diesel engine shall be capable of "black starting" and

shall be rated so that at least six immediate consecutive "blackstarts" can be attempted.

The diesel engine starting system shall be complete with all equipment including self

contained oil system, jacket water cooling system, dc starter motor, dry type filter, batteries

and charger system, fuel system and tank, hydraulic torque converter and hydraulically

operated, solenoid-valve controlled jaw clutch with automatic disengagement at turbine self-

sustaining speed.

2.2.4.18 Lubricating Oil System

i) General

The lubricating provisions for the turbine, generator, main gearbox and accessory gearbox

shall be incorporated in a common lubrication system. The lubrication system shall be

vented to atmosphere and shall include, but not necessarily be limited to, the following

equipment:

Main lubrication oil pump shaft driven from the accessory gearbox.

Oil reservoir integral with the turbine base

Full flow AC motor driven auxiliary lubrication oil pump

Partial flow DC motor driven emergency lubrication oil pump

Full flow AC motor driven auxiliary hydraulic oil pump

Lubrication oil heater

Pressure relief valve in the main pump discharge

Dual full flow 5 micron filters with changeover valve for lubrication and trip oil systems

plus dual 5 micron filters for hydraulic oil system.

Bearing header pressure regulator

Air blast cooler for direct cooling of the oil


30/06/1999 Page 22 SP-1118

The tank vent and all bearing vents, (including the generator) shall be piped to the turbine

exhaust gas outlet such that oil vapour is entrained into the exhaust gas efflux. The vent

pipework shall be designed such that no oil drips back along the outside of the pipework.

The complete lube oil system including off skid pipework and cooler tubes/headers shall be

manufactured from 316 SS except for the lube oil storage tank, which may be carbon steel.

ii) Cooling System

Lubricating oil coolers shall be of the air blast type cooling the oil directly and shall comply

with the requirements of this specification and API 661 as modified by DEP 31.21.70.31.

The lubricating oil cooling system shall include thermostatically operated bypass valves and

fans to maintain oil temperature within safe operating limits.

The number of fan units provided shall be such that peak load can be maintained under the

most adverse ambient conditions with one fan unit out of service.

The cooling system shall be designed for ambient air conditions of 60ºC and 50% RH with a

10% margin in heat transfer surface.

Single speed fans shall be provided and shall be of the forced draught type located below the

cooler. The fans shall be driven by suitably designed "V" belts and pulleys. V belts shall be

designed for transmitting the maximum load at the design ambient conditions.

Any greasing points shall be accessible from ground level without the need to dismantle

guards etc. A central greasing point is preferred.

The fans and coolers shall be protected against foreign objects by means of non sparking bolt

on screens constructed from 8 SWG 50 mm square galvanised wire mesh.

All valves and instrumentation shall be accessible from ground level and provided with

suitable platforms and walkways. The lowest point of the cooler/fan assembly shall be a

minimum of 2.3 metres above ground level.

iii) Flushing Procedure

The entire lubrication oil system shall be flushed with the bearings and other lubricated items

by-passed for as long as necessary to obtain a thoroughly clean system.

All flushing oil, temporary pipework, strainers and any other equipment required shall be

supplied.

2.2.4.19 Air Intake and Exhaust System

i) Air Intake System

The intake system shall comprise of self cleansing filtration equipment, mist separator,

silencing, ducting, trash screens, guidevanes, internal lighting and all necessary support

structures, walkways, ladders and fittings. The minimum filtration efficiency shall be 95%

for 10 micrometre particle size as defined by the NBS weight method.

All ladders, platforms and special lifting and handling devices necessary for access to, and

maintenance of the filtration equipment shall be included. Air tight inspection doors shall be

provided in such number and position as to allow access to all parts of the intake works for

inspection and maintenance. In particular, it shall be possible to carry out a close-up visual

inspection of the first blade rows of the gas turbine compressor. All doors shall be provided

with locks. Refer to PDO standard drawing 23003 A, type A.

The design shall assume a maximum 3 second wind gust velocity of 47 m/s from any

direction. The intake structure shall be arranged at a suitable height above ground level to

prevent undue ingress of dust and in any event shall have a minimum ground clearance of 3.5

m.

All ductwork shall have a minimum thickness of 5 mm. Automatic bypass doors are not

required.

The self cleaning inlet filtration system shall utilise single stage high efficiency media filters,

which shall be automatically cleaned of accumulated dust thereby maintaining the inlet

pressure drop below a pre-set upper limit.


SP-1118 Page 23 30/06/1999

The air filtration system offered shall be capable of operating under any possible

combination of adverse site conditions that occur (such as high atmospheric dust loading

together with high humidity) without adversely affecting the gas turbine, the filtration system

or the effectiveness of the filter cleaning process.

The air supply for the filter cleaning system shall be a 'bled' air from the gas turbine

compressor. The air shall be cooled and dried by means of desiccant dryer units, which shall

be of the "heatless" twin vessel type suitable for continuous operation. The capacity of the

bled air system and the quality of the air shall be suitable for the pulse cleaning requirements

of two gas turbine and generators inlet air filtration systems. As a back-up supply and for

off-load cleaning the system shall be connected to the station air supply via a normally closed

valve.

A fully automatic sequential system shall be provided, operating a series of solenoid-

operated valves, each of which shall control the cleaning of a small number of filters. The

sequential system shall be controlled by:

Filter differential pressure

Timer Control

Manual initiation

A differential pressure gauge and associated switch be provided for monitoring high

differential pressure and similar equipment for monitoring low pressure and or for low

pressure in the pulse cleaning air supply.

All air distribution pipework shall be manufactured from stainless steel.

The filter elements are required to have a guaranteed life of two years.

Lifting equipment and access trolleys to assist in the replacement of filters and for

maintenance of the air inlet filtration system shall be provided.

ii) Exhaust Gas System

The exhaust gas system shall be complete with all necessary gas-tight ducting, expansion

joints, turning vanes, stack, supporting steelwork, flanges, inspection doors, silencers and

any other equipment required to complete the system.

The height above ground level of the exhaust stacks shall be such to ensure that the 24 hour

concentration of sulphur dioxide (SO2) does not exceed 300 micrograms per cubic metre, but

a minimum of 15 metres above grade level shall be maintained.

2.2.5 Pipework and Fittings

Pipework inside the gas turbine package can be to the manufacturer’s standard but as a

minimum shall be based on a recognised International standard and suitable for the specified

fuel gas, suitable for the medium specified. (E-g) sour gas NACE standards.

All pipework and fittings shall comply with DEP's 31.38.01.10, 31.38.01.11 and 31.38.01.15

for equipment outside the gas turbine package.

Pipework joints shall be welded wherever possible subject to the requirements for site

installation and maintenance. All pipes and fittings shall be suitably cleaned and protected

prior to delivery and the ends suitably protected.

2.2.6 Fire and Gas Detection and Protection Equipment

2.2.6.1 General

The system supplied shall be complete in all respects and integrated into the Station Fire

Protection System. The system shall comply with the requirements of PDO standard ERD

No. PDO-ES-DE-88-02 "Fire and Gas Detection and Protection". Microprocessor based fire

alarm systems are acceptable if provided in accordance with DEP 32.30.20.11.

2.2.6.2 Fixed Fire Protection System


30/06/1999 Page 24 SP-1118

A fixed fire protection system shall be provided within the Gas Turbine/Generator acoustic

enclosure to meet the requirements of PDO standard ERD No. 88-02 "Fire and Gas

Detection and Protection".

The fire protection medium shall not be piped to the GT unit auxiliary control cabin.

Safety signs shall be provided in accordance with Section 5.8 of PDO standard ERD No. 88-

02 "Fire and Gas Detection and Protection".

A facility to inhibit the release of the extinguisher shall be provided adjacent to each

compartment on each side of the Gas turbine package and shall consist of a lockable two

position switch complete with local and remote indications of isolation. A suitable door

interlock to inhibit release of the extinguisher when the compartment door is open shall be

provided.

2.2.6.3 Fire and Gas Detectors

A minimum of four Ultra Violet (UV) detectors shall be provided for each of the following

gas turbine enclosures:

GT unit Auxiliary cabin.

Turbine compartment.

Gearbox compartment

Generator and exciter compartment

The detectors shall preferably be located on the inside of the enclosure doors to facilitate

maintenance without having to enter the turbine compartment or shut-down the machine.

In addition, the turbine compartment and any other compartment in which a fire risk exists

shall be provided with a minimum of three heat detectors of fixed temperature, rate

compensated type.

A minimum of three gas detectors shall be installed in the discharge ventilation air ductwork

of the gas turbine enclosure. If there are other separate compartments where fuel gas could

escape then each associated ventilation ductwork shall contain a minimum of 3 units. The

detectors shall be located at a convenient location to enable maintenance to be performed

without shutting down the gas turbine.

The end of line resistors shall be outside the hot enclosures.

Manual alarm call points, break glass type or equivalent, shall be provided and located near

enclosure access doors.

2.2.7 Doors

Hinged personnel access doors to the compartments shall be provided and designed so that

they can be opened by a pushknob on the inside. On no account shall it be possible to lock

the doors to prevent such exit.

Each access door shall be provided with a suitable lock, lockable from the outside only, and

capable of being quickly overridden from the inside if the door should be locked whilst the

enclosure is occupied.

2.2.8 Heaters and Ventilators

Electrically operated heaters and/or fans shall be provided to ensure that air circulation in the

machine and duct air space is maintained so as to prevent condensation and corrosion during

periods of shutdown. Such heaters shall be automatic in operation with thermostats and shall

be interlocked with the machine start-up and shut-down sequences that they do not operate

when the machine is running.

2.2.9 Thermal Insulation


SP-1118 Page 25 30/06/1999

All external thermal insulation with the exception of the exhaust ducting, shall be of the

blanket type and be capable of removal and replacement for overhaul purposes without

damage. Thermal insulation shall be provided, where appropriate, to prevent adjacent

concrete surfaces from reaching excessive temperatures and for personnel protection.

Non-asbestos, chemically inert, thermal insulation shall be applied to all normally accessible

exposed surfaces of equipment which may exceed a temperature of 65ºC, when the ambient

temperature is 50ºC.

The insulation shall be encased by metal cladding or other approved means. Where the

cladding is readily accessible to personnel during the unit operation its surface temperature

shall not exceed 65ºC. If this is not practical additional guarding or warning notices shall be

provided.

2.2.10 Generator and Excitation System

2.2.10.1 Generator

Generator shall comply with DEP 33.65.11.31 and shall meet the specific requirements of

this SP.

At the rated speed the Generator shall have sufficient capacity to continuously match the

rated output of the gas turbine at a lagging power factor of 0.8 under the ambient

conditions specified. Further the generator capacity shall match the turbine output at 0.8 PF

lag without exceeding class B temperature limits at site conditions for the ambient

temperature range of - 5ºC to 50ºC at site conditions with the cooling system operating

normally and shall match the peak load output of gas turbine without exceeding the Class F

temperature limits

The generator shall be capable of supplying its rated output at rated voltage and rated power

factor at a frequency which may vary between 1.02 pu and 0.96 pu. The supplier shall

guarantee the lead power factor capability under the condition when the automatic AVR

channel is not in operation and the machine is under manual control. The generator shall be

capable of absorbing 10MVAR when the HV system voltage is 10% higher than the nominal

voltage.

The short circuit ratio shall be based on the no-load excitation current at rated generator

voltage and the short-circuit excitation current at rated generator current. It shall be not less

than allowed by IEC-34.3.

The generator shall be totally enclosed, degree of protection IP54 having brushless excitation

with main and pilot exciters.

Generator and exciter shall be provided with anti-condensation heaters.

2.2.10.2 Excitation System

The generator excitation shall comply with the requirements for IEC 34-3. The excitation

system shall be of the rotating field exciter type with a rotating diode rectifier, thus providing

a completely brushless form of excitation. The AC source for the excitation shall be derived

from a separate AC pilot exciter mounted on the generator shaft. The excitation system shall

be suitable for control by the static type of automatic voltage regulator.

Provision shall be made for testing the excitation equipment without the operation of the

main generator. The equipment shall be complete in every respect and designed for the

highest degree of reliability and minimum maintenance requirements.

2.2.10.3 Exciter

i) General

The nominal exciter response as defined in Appendix A, of IEC 34-3, shall not be less than

1.0. The continuous rated current and voltage of the main exciter at the maximum specified

ambient temperature, shall not be less than 110% of the generator excitation current and

voltage required to maintain rated output at the terminals of the generator.


30/06/1999 Page 26 SP-1118

The ceiling voltage shall not be less than 120% of the machine excitation voltage. The

exciter shall be enclosed to degree of protection IP54 and cooled by means of cooling air

taken from and returned to the generator cooling system.

ii) Rectifier for A.C.Exciters

The rectifier bridge shall comprise a simple three phase full wave configuration. The silicon

diodes shall be mounted on heat sinks suitable for providing adequate heat transfer to the

cooling medium. Each bridge arm shall consist of two or more diodes in parallel per arm

with suitable protection incorporated.

The maximum reverse voltage appearing across the rectifier bridge shall be determined from

a calculation of the induced voltage following a faulty synchronisation. The provision of

inverse voltage suppression is not acceptable. The total capacity of the diodes in the rectifier

bridge should be such as to provide a reserve capability of at least 20%.

The diodes shall be continuously rated such that at generator full load, field forcing and fault

conditions can be carried with one failed device per bridge section. Diode failure indication

in the operating condition shall be provided.

2.2.10.4 Voltage Regulation

i) General

The system shall be capable of either automatic or manual operation and should incorporate

appropriate auto/manual changeover facilities.

The system shall include suitable limit control features, fault detection and protection

features including transformer overfluxing protection. Excitation limiter shall be ambient

temperature compensated.

The voltage regulation and main exciter field suppression equipment shall be supplied as part

of the Generator Control Panel and shall be a high standard of quality and reliability and

fully suitable for the control and protection of the generator.

ii) Automatic Voltage Control

The automatic voltage regulator shall be of the continuously acting type with no dead bands

enabling control of the excitation over the whole generator operating characteristic.

The AVR shall be capable of maintaining the generator terminal voltage within 1.0% of the

set value for any voltage deviation over the whole load range of the generator.

Stabilising adjustment facilities, gain and feedback adjustments shall be graduated and

secured from interference.

The voltage response characteristic shall be given for AVR damping control at normal,

maximum and minimum setting respectively. At normal position of the stabilising control

the generator voltage response times for a 10% step-change on open-circuit shall not exceed

a recovery time t = 0.5 seconds and a settling time t = 2.0 seconds. The value of the

overshoot voltage shall not exceed 50% of the step-change applied or 10% of rated voltage

under the most extreme condition of field forcing.

iii) Protective Devices

A minimum excitation limit device shall be incorporated to prevent the AVR reducing the

generator excitation below a value, which might endanger power system stability limits. The

limit unit shall be arranged to provide an alarm and interlock in the event of extreme low

excitation when operating under either automatic or manual excitation control.

The characteristic of the VAR-limiter shall be adjustable and facilities shall be provided so

that the VAR-limiter operating characteristic can be adjusted to any setting within the range.

Over-excitation protection shall be incorporated to ensure that if excessive excitation is

sustained beyond an adjustable preset current/time limit, the excitation is automatically

ramped down. The current/time setting shall be such that no damage will be caused to any

part of the AVR or the excitation system.

The AVR shall in addition include the following protective devices, which shall trip the AVR

and change to manual control and/or initiate appropriate alarms:


SP-1118 Page 27 30/06/1999

Over voltage protection

Overcurrent protection

V.T. fuse failure protection

AVR failure protection

Overfluxing protection (volts/Hz protection)

AVR power supply failure protection

The overfluxing protection shall be part of the excitation control system and shall be

operative during both automatic and manual modes of excitation control. The protection

shall prevent the transformer magnetic flux from rising to a value at which the

voltage/frequency ratio, pre-set within the range 1.00 to 1.24, would be exceeded. This

protection shall ensure that generator and unit auxiliary transformer V/Hz withstand

capability is not exceeded.

iv) Manual Control

Facility for manually controlling the excitation shall be provided, primarily for generator

commissioning and maintenance purposes. Control shall be possible from approximately

30% rated voltage at no-load to a maximum of 115% rated voltage at full load.

Means for both local and remote operation of the manual control shall be provided. An

auto/manual balance indicator and change-over facility shall be provided at the Generator

Control Panel (GCP) however, remote changeover shall be inhibited when the local control

is in use.

A follow-up device shall be provided to automatically adjust the standby excitation control

so that in the event of a changeover from automatic to manual control there will be a

minimum change in the level of excitation

An automatic limiter shall stop the automatic follow-up device or the manual voltage

controller, from reducing the manual voltage regulator setting below the prescribed safe

limits of excitation for the generator when under manual control. The characteristics of the

limiter shall have the same range of adjustment as the VAR limiter of the AVR channel, but

when commissioned shall be set for less leading conditions than the VAR limiter.

v) Current Compounding

Quadrature droop compensation shall be provided to ensure correct sharing of reactive

power in accordance with generator rating.

The compensation shall have an adjustable compounding range of +10% and shall be so

connected that the compounding can readily be taken out of service. The current transformer

required for compounding shall be included as part of the excitation equipment.

2.2.10.5 Generator and Exciter Field Suppression Equipment

Generator field suppression equipment shall be provided for minimising as much as possible

the damage caused by the certain internal generator and excitation system faults i.e. those

faults, which cannot be switched off by tripping the generator breaker.

The exciter field suppression equipment shall be provided and may be accommodated within

the AVR cubicle. The field switches shall be capable of making and breaking the circuits

under the most onerous fault conditions. The switches shall be suitable for local and remote

as well as automatic operation. The generator field switch shall also be suitable for manual

operation.

Means shall be provided for indicating locally and remotely whether the switches are in the

open or closed position. The field suppression resistor shall be non-inductive and rated to

suppress maximum field current as quickly as possible.

2.2.10.6 Generator Cooling

Generator cooling shall be of the protected ventilated type with a filtered ambient air supply

through a ductwork system and circulated by fans on the rotor. The exhaust air shall be

ducted to atmosphere. The inlet filtration system shall consist of a pulse air cleaning system,

of the same design and make as the gas turbine air intake system.


30/06/1999 Page 28 SP-1118

2.2.10.7 Generator Temperature Measurement Equipment

Temperature detectors and indicators of approved type shall be provided for measuring the

maximum internal temperature of the generator and the cooling medium temperatures.

Provision shall be made for the following minimum requirements:

(a) Stator windings, between coils in slot 9 positions

(b) Stator core 3 positions

(c) Ambient air inlet 2 positions

(d) Hot air outlet 2 positions

(e) Spare on terminal board for test purposes 2 positions

Each indicator shall have adjustable contacts for initiating a high temperature alarm, which

shall be independent of the multipoint temperature scanner.

The leads from the temperature detectors shall be brought out to a terminal box on the

generator in such a position, which is accessible during normal operation of the unit. All

temperature detectors shall have the same characteristics. A multi-point temperature scanner

scaled 0 to 150ºC with selector switch shall be provided in the Generator Control Panel.

2.2.10.8 Parallel Operation

The generator shall operate satisfactorily as a single unit or in parallel with all or any other

units under all normal working conditions. Unit/parallel selection shall be automatic with

manual override. It may be assumed that the other units run satisfactorily in parallel with

each other and have no abnormal characteristics. The Generators will be operating in

parallel with other Generators in the PDO system. Study to ensure that no system

oscillations develop should be carried out and, if required, means of damping these

oscillations by power system stabiliser shall be provided.

2.2.10.9 Neutral Earthing

The generator star point shall be earthed through the primary winding of a earthing

transformer with an unbreakable grid type resistor connected across its secondary winding.

Means of disconnecting and isolating the generator star point shall be provided.

The distribution transformer shall be of the air cooled type with cast resin Class H insulation.

The equipment shall be located within the generator enclosure.

2.2.10.10 Main Terminals

Busbars and connections shall generally comply with BS 159 and shall be of electrolytic

copper.

Outgoing line terminals shall be brought out into a separate terminal box and in order to

enable the outgoing connections to be made. The terminals and the leads from the winding

to the terminals shall be suitably insulated and rigidly supported. The design shall be such as

to reduce the probability of a phase to phase or three phase fault. Earthing points shall be

provided at outgoing line terminals for applying maintenance earth.

The star point terminals shall be brought out and connected together for earthing. The

arrangement shall incorporate current transformer with terminal boxes for connecting the

secondary connections to the outgoing multicore cables.

The spacing of the terminals and accommodation within the terminal boxes shall be

verminproof with adequate clearances.

The phase ends shall be appropriately marked and painted red, yellow and blue respectively,

in the order of their phase sequence.

The insulation of busbars and their connections shall be capable of withstanding without

damage the thermal and magnetic effects of a short-duration solid phase to earth, or phase to

phase fault at the stator terminals.

A line side cubicle shall be provided where all the line terminals shall be brought out through

bushings. This cubicle shall be suitable for external cable termination or busduct connection.


SP-1118 Page 29 30/06/1999

Access to busbars and associated connections shall be gained only by the removal of bolted

or screwed access covers or doors, which shall be indelibly, marked "DANGER HIGH

VOLTAGE". Two suitable earth terminals shall be provided on the stator frame.

2.2.11 Wiring and Terminal Boxes

All electric wiring on the skid shall be 1000 volt grade and fire resistant. Wiring not

protected by metal conduit or covers shall be by means of steel wire armoured cables. All

cable glands, plugs and sockets shall be flameproof and waterproof type.

All terminal boxes shall be accessible when the machine is in operation.

One or more separate terminal boxes shall be provided for each of the following:

Generator Line

Generator Neutral

Stator Winding Temperature Detectors

Stator and Exciter Heaters

Main Exciter terminations

Pilot Exciter terminations

Temperature and Pressure Switches etc.

Gas Turbine D.C. connections.

Gas Turbine A.C. connections.

Gas Turbine thermocouples.

All spares cable cores shall be terminated using a separate terminal for each core.

2.2.12 Temperature Classification of Electrical Equipment

Hazardous area classification shall be as per IP Code 1P 15.

For each enclosure of the gas turbine and other enclosures the maximum final temperature

attained at the maximum rated load at the maximum ambient temperature conditions shall be

determined during the design phase. The Temperatures determined shall include any

temperature rise which may occur due to a complete cycle of peak load duty at maximum

specified ambient temperature which is following by the rated base load operation at

specified maximum ambient temperature. All the equipment inside the enclosure including

but not limited to cables, terminal blocks, lighting, etc. shall be designed and certified to

work in the temperatures determined in the design phase.


30/06/1999 Page 30 SP-1118

2.3 EMERGENCY DIESEL GENERATING SET

2.3.1 General

An auxiliary diesel generator shall be provided at the Power Station to facilitate ‘black start’,

supply certain essential loads during periods of non-availability of the units and supply

critical station auxiliaries during prolonged shutdowns.

The diesel generator shall be a skid mounted, packaged unit and shall be complete with the

following:

Controls

Cooling System

Lubrication System

Fuel Supply System

Exhaust System

Starting System

Enclosure suitable for external location

The complete package to be located under a Sunshade.

The diesel engine shall comply with the requirements stipulated in DEP’s 33.65.11.32 and

31.29.80.30.

2.3.2 Duty

The diesel generator set shall be continuously rated at a site ambient air temperature of 50ºC

and pressure of 98 kPa(a). Reference shall be made to SP-1103 Appendix 2 as regards the

ambient temperature to be considered for the selection of electrical equipment. The diesel

engine shall be provided with a jacket water heater to enable quick starting and loading

capability. The sizing shall consider a total of three gas turbines in the Power Station.

During periods when the power station is under total black-out, the diesel generator shall

supply the following loads :

All equipment and panel heaters

Fuel gas treatment electric water bath heater

All battery systems at boost charge rateAll loads connected to the DC systems and load

of one battery set on boost charge

Essential instrument supplies

GT Package enclosure lighting, ventilation and air-conditioning

Instrument air compressor package

Control building small power requirements, lighting, ventilation and air conditioning

Emergency lighting of outdoor areas.

Any other loads identified during the design phase as “essential load”.

The generator sizing calculation shall allow for a 15% margin.

2.3.3 Location

The diesel engine set shall be provided in a packaged enclosure. The enclosure shall be

suitable for the environmental conditions at site and shall be designed to prevent the ingress

of dust, sand and moisture.


SP-1118 Page 31 30/06/1999

2.3.4 Diesel Engine

The diesel engine shall be of the four-stroke type and may be either naturally aspirated or

turbo-charged and shall operate at a nominal speed of 1500 rev/min or less.

Cooling shall be by means of a radiator mounted on the engine skid and an engine driven fan

and water pump. The radiator shall be fitted with a duct flange and ductwork so that the

cooling air will be exhausted outside the enclosure. An automatic, thermostatically

controlled jacket water heater shall be provided to maintain the jacket water temperature

during periods of shutdown.

Combustion air shall be drawn via an inlet air filter.

The exhaust shall be routed via a flexible connection and silencer to the outside and arranged

to discharge at a high level.

Oil breathers etc. shall not discharge into the enclosure but shall be routed to an external

source.

All rotating parts shall be adequately guarded.

2.3.5 Fuel System

The fuel will be locally available diesel oil equivalent to Class A2.

A header tank shall be provided, sized to hold sufficient fuel for 12 hours operation of the

diesel generator when operating at 100% MCR and shall be complete with the following:

Access ladder

Cover to enable internal inspection

Overflow and drain with valve

Outlet valve

Filling nozzle and semi rotary filling pump

Return nozzle

Vent with flame arrestor

Level gauge

Separate concrete bund for the fuel tank

Level alarms

All interconnecting pipework between the tank and the diesel engine shall be provided and

the engine shall be fitted with a fuel filter. No screwed or socket welded connections are

permitted.

The fuel supply line shall be fitted with a solenoid operated ESD Valve which shall be

integrated with the fire protection system.

2.3.5.1 Fuel Supply Pipework

Inlet connection shall be a 50 mm NB (BSP) connection with brass cap.

Materials for pipework, valves and fittings shall be according to PDO DEP 31.38.01.15.

The pipework shall be separate from the supply to the Gas Turbine starting diesel tank.

2.3.5.2 Fuel Loading

A quick connection coupling (PDO approved type) and a flexible hose filling point to enable

filling of diesel storage tank shall be provided.

The filling point shall be located inside the station boundary in an area suitable for filling by

road tanker. Provision shall be made for earthing the tanker during unloading with a flexible

earthing cable reel. The cable is to be stored in a weatherproof container adjacent to the

filling point.


30/06/1999 Page 32 SP-1118

2.3.6 Generator

The generator shall have a continuous maximum net rating to match the peak load output of

the diesel engine between 5C and 50C at 0.8 power factor (lagging) without exceeding

temperature rise limits specified for Class B insulation. Generator shall be Class F insulated.

Generator shall conform to IEC-34. The rated voltage shall be 415V at a rated frequency of

50Hz. The enclosure shall be drip-proof screen protected and cooled by means of open

circuit air cooling. The unit will be required to operate in parallel with the station auxiliary

power system for maintenance purposes. Synchronising facilities required to achieve this

shall be provided on station LV board.

The generator shall be provided with a rotating brushless excitation system based on a full

wave rotating rectifier assembly with AC exciter. Means shall be provided for both manually

and automatically controlling the excitation. The automatic voltage regulator shall be of the

solid state type.

The generator stator shall be star connected with the neutral brought out for connection to the

system earth via a motor operated earth switch with suitable interlocks. The neutral shall be

isolated from the station LV board when the generator breaker is off.

Suitable anti-condensation heaters shall be provided which shall be energised automatically

when the generator is shutdown.

2.3.7 Controls, Protections and Instrumentation

All necessary controls and safety devices shall be provided, which shall be housed in a

combined diesel generator and instrument air package control panel located in the control

room. All interconnecting wiring shall be provided.

The diesel generator shall be arranged for automatic starting by a single manual initiation at

the control panel or on loss of voltage to the 415V Station Auxiliaries Switchboard and auto

restoration when mains supply is restored. The starting cycle shall include a prelubrication

or cranking period to ensure proper lubricating oil circulation before the machine is fired.

The generator shall be capable of being synchronised to the station LV board for routine load

testing.

It shall be possible to lock the start pushbutton to prevent unauthorised starting.

The following indications and control functions shall be provided on the

instrumentation/control panel.

Auto/Off/Manual selector switch - Keylock operation

Unmanned/manned selection switch - Keylock operation

Start pushbutton

Stop pushbutton

Emergency stop pushbutton

Voltmeter/Ammeter phase selection switch, Power factor meter, Frequency meter, kW

meter and kWh meter.

Speed raise/lower pushbutton

Excitation raise/lower

Trip reset pushbutton

All individual trip indications.

The Generator electrical protection shall be in accordance with the drawing STD-4-6101-02-

3-A (protection Scheme - 2 of LV Generators).

Normal shutting down of the unit shall include a cool down running period if required to suit

the diesel engine. Initiation of shut-down using the emergency stop pushbutton shall cause

the machine to shut-down immediately.


SP-1118 Page 33 30/06/1999

2.3.8 Starting

Starting shall be by batteries, which shall be sized for at least 6 consecutive start attempts. A

battery charger with float/boost selection shall also be provided. The batteries and battery

charger shall preferably be mounted on the package skid.

A supply to the battery charger shall be provided from the Station 415V switchboard.

The diesel generator set shall be capable of starting without any external electrical supplies

being available.

2.3.9 Fire Protection

A fixed dry powder or water mist fire protection system shall be provided for the enclosure.

2.4 GAS TREATMENT PLANT

2.4.1 General

Each gas turbine shall have its own gas treatment plant. The complete fuel gas supply and

treatment system shall be designed to supply the gas turbine from the terminal points as

defined by the Company. The design of the gas supply and treatment system shall be such

that it is capable of supplying the gas turbine with clean gas at the correct pressure and at a

temperature that will avoid any danger of condensate and debris entering the gas turbine.

The design and scope of the gas treatment facilities described in this section are typical of

PDO’s preferred design for power plant gas treatment facilities. Variations in fuel gas

source, supply and composition may require modification to the proposed design.

The PEFS of the gas treatment system are typical of the plants installed and should only be

used as a guideline. The configuration of the plant shall be designed to suit the properties and

composition of the selected fuel gas.

2.4.2 Scope of Supply

The scope of supply for each gas treatment plant shall normally include, but not be limited to

the following:

Liquid Knock-out vessel

Water bath type electrical heater

2 x 100% Pressure reducing station

Condensate collection system, including drain tank and condensate transfer pumps

2 x 100 % Filter Separators

Flow metering

All pipework, valves, controls and instrumentation necessary for the safe and efficient

operation of the fuel gas supply system.

Vent stack and sterile area.

If a dry fuel gas is to be used then the knock-out vessel should be replaced or supplemented

with a upstream strainer for dust removal.

The scope of the fuel gas supply and condensate return system may include off-plot pipeline

requirements, if specified by the Company in the individual project scope.


30/06/1999 Page 34 SP-1118

2.4.3 Gas Supply and Analysis

The Company will provide the best available fuel gas analysis including supply pressure and

temperature. However, this shall be verified by carrying out the gas composition analysing

and reviewing available Company data. The worst case data (Sample analysis or Historical)

should be applied for design.

Variations in Wobbe index greater than 5 percent when firing a variety of gases could result

in instability or the need to install a second burner system.

2.4.4 Design Criteria

The gas turbine will be required to operate on any combination of the specified fuel gases.

The system shall be arranged in such a way as to facilitate easy and quick removal of the

filter elements for cleaning or replacement.

The layout of the pipework to the gas treatment skids should be carefully designed to ensure

that no liquid slugs are carried over to the gas turbine following a period of extended

shutdown.

The onplot gas supply piping from the terminal points up to the fuel gas treatment plant area

shall be the same size as the offplot fuel gas supply pipeline to avoid future bottlenecking

should the plant be extended in the future.

Each fuel treatment plant shall be designed to meet the maximum peak load requirements of

the gas turbine supplied at all site ambient air temperatures between 5ºC and 50ºC.

All carbon steel pipework and pressure vessels shall have a corrosion allowance of at least

3mm.

The main inlet valve to the treatment skid shall be provided with a bypass for pressure

equalisation. If the pressure reduction is accomplished in two stages then there shall be

adequate length of pipe between two stages to secure minimum turbulence.

The capacity of the condensate collection system shall be sufficient to continue to operate at

full load for 24 hours from the time of the liquid high level alarm, without being able to

export condensate. Failure of any part of the condensate system shall not result in a

complete shut down of the plant.

Means shall be provided to directly export condensate under its own pressure without the use

of pumping from the collection tanks.

2.4.5 Fuel Gas and Condensate Pipelines

The offplot fuel gas and condensate pipelines between the power plant and facilities, shall be

designed in accordance with ANSI B31.4 AND B31.8, except where modified by DEP

31.40.00.10. Carbon steel pipelines shall have a corrosion allowance of 3mm.

The Company shall advise either the size of the pipelines or the number of generating units

the pipeline shall be sized for.

Both pipelines shall be buried and cathodically protected, unless specified otherwise. The

pipelines shall be constructed in accordance with PDO pipeline specification PCS 1.

Where pipeline cleaning is required, the launcher and receiver shall be designed in

accordance with the relevant SP.

2.4.6 Gas Treatment Skid

A skid mounted gas treatment plant shall be provided capable of removing contaminants

from the fuel gas to achieve the required quality for the gas turbine unit, and supplying the

required quantity of gas at the specified conditions.


SP-1118 Page 35 30/06/1999

The gas treatment plant shall normally consist of a K.O. Vessel, water bath type heater,

pressure reducing station and filter separator unit.

All plant and equipment necessary for the safe and efficient operation of the plant shall be

provided.

All automatic valves shall be pneumatically operated. Instrument air requirements shall be

supplied from the compressed air system.

Screwed connections or socket welded fittings on any part of the fuel gas supply, drain or

vent systems are not acceptable.

2.4.7 Water Bath Heater

One 100% duty indirect type gas heater shall be provided in the fuel gas plant. All plant and

equipment necessary for safe and efficient automatic operation is to be included.

The heater coil is to be designed in accordance with API 12K and the electric heater is to be

BASEEFA certified.

The capacity of the heater shall be adequate to ensure that the temperature of the fuel gas to

the burner is sufficiently high. A gas temperature of at least 28oC higher than the gas dew

point temperature shall be achieved (downstream of the unit pressure control valve) under all

operating conditions.

The heater shall be of the water bath type with two 100% (duty/standby) electric immersion

heaters. The heater shall preferably be fitted with an expansion dome suitable for supply of

make-up water from the existing station water storage and supply system. Each heater

element shall be split into 2 x 50% steps to provide a step control for heating.

When the gas turbine is out of service for an extended period the heater shall automatically

shutdown.

Precautions necessary to inhibit scaling inside the heater vessel shall be taken. The heater

shall be fitted with inspection manholes, vent, drains and safety devices. A manually

operated bypass shall be fitted and shall be capable of being positively isolated.

2.4.8 Pressure Reducing Station

A pressure reducing station shall be provided to regulate the supply gas pressure to the gas

turbine (note final pressure regulation will be undertaken by the gas turbine pressure control

valve).

The pressure reducing station shall consist of 2 x 100% pressure let-down lines each

consisting of two pressure regulating valves in series such that should one valve fail in the

open position the other shall be able to accept the total pressure drop. The pressure reducing

control valves shall be of the pneumatic type controlled by downstream pressure (measured

by means of pressure transmitters). The use of gas as the control medium is not permitted.

The pressure reducing valves shall not be considered as fail-safe protection against over

pressure. It shall be ensured that, with both valves failed in the open position, the relief

valves and vent system will protect the downstream pipework from over pressure.

2.4.9 Fuel Gas Knock Out Vessel

A single vertically mounted 100% duty liquid knock-out vessel shall be provided. It shall be

complete with all inspection manholes, demister, vents and automatic and manual drains.

The vessel and its internal components shall be essentially maintenance free for continuous

unattended operation.

The vessel shall be sized in accordance with the DEP 31.22.05.11.Gen. liquid holding

requirements and installation of level alarms are to be reviewed and consideration should be

given to the unmanned status of the site.


30/06/1999 Page 36 SP-1118

It shall be ensured that adequate safeguarding facilities are provided to prevent gas blow-by,

liquid carryover and liquid overfilling. The mechanical integrity of the vessel is to be

maintained under all circumstances (i.e. fire).

All vessel nozzles shall be provided with weldneck flanges. The minimum nozzle size shall

be 50 mm.

2.4.10 Pipeline Filters

Pipeline filters are to be installed in pipelines, when pipeline dust is likely to be encountered.

Two 100% duty filters shall be provided upstream of the pressure reducing station, complete

with access cover, vents, drains and instrumentation.

The 2 x 100% filters shall be provided with pressure differential switches and actuated

changeover valves. Increase in the backpressure on the duty filter shall result in automatic

changeover to the standby unit, without interruption to the fuel gas supply. Filter high

differential pressure shall be repeated as an alarm to the control room.

The filters shall be of a high efficiency type with removable filter elements that can be

cleaned without the use of any additional lifting equipment. The filters, changeover valves

and instrumentation shall be mounted on a single skid and to allow access for maintenance

and filter element cleaning. Access covers shall be interlocked to prevent accidental opening

while in operation. Filter elements shall preferably be manufactured from stainless steel but

alternatives may be considered dependent on particle size, composition and flowrate.

In the event of actuator supply failure, the actuator shall stay in its current position.

The pipeline dust collected in the filter is often pyrophoric, erosive and corrosive. To

prevent ignition when opening the filter it shall be first dampened with water. The design

shall include the above provisions.

The Company will advise the likely mass flowrate, composition and particle size of the

pipeline dust/debris so that the filter and element can be adequately sized.

2.4.11 Filter Separators

Two 100% duty two stage filter separator units shall be provided on the skid. The first stage

shall be Fibreglass filter-coalescer elements working on the agglomeration principle. This

filter pack shall collect all relatively large liquid droplets and most of the solid particles. The

second stage shall be a mist eliminator preferably of the vane impingement type with the high

separation efficiency for smaller liquid and solid particles.

The agglomeration section and the second stage mist eliminators shall be arranged in such a

way as to facilitate easy and quick removal of the elements for cleaning or replacement.

An adequately sized liquid collection zone shall be provided at the bottom of the tank. Liquid

droplets collected in the coalescer elements as well as in the mist eliminator shall eventually

drain into this collection zone.

Duplicate automatic drains shall be provided, one for each stage. A "fail-safe" liquid level

control mechanism to prevent the escape of gas during normal operation shall be provided on

the vessel.

2.4.12 Drains and Condensate Disposal

The drains from each item of plant shall be fitted with a manual isolating and non-return

valves. The drains from the gas treatment skid shall be grouped and connected to a common

drains header. Drain lines shall be sized to conform to PDO standards and must take into

consideration the flashing of the liquids on pressure reduction through the level control

valves. The minimum pipe size for condensate drains shall be 40 mm.

Adequate drainage liquid handling facilities must be installed, to cater for liquid disposal

when the plant is shutdown for maintenance etc. and for normal "continuous" liquids


SP-1118 Page 37 30/06/1999

disposal from the knock-out vessel and Filter/Coaleser Separators. Due consideration of the

system pressures and flashing nature of the hydrocarbon liquids must be provided.

The condensate collection tank shall be buried.

2.4.13 Pressure Vessels

The knock-out vessel, gas filters/separators shell and the heater shell shall be designed as

pressure vessels in accordance with BS 5500 or ASME as amended by the latest issue of

DEP 21.22.10.32. The minimum nozzle size for process and instrumentation connections

shall be 1½ inches.

Holes required to form the dished head shall not be sealed with a screwed plug.

If required, the vessel size shall be increased beyond the volumes calculated to satisfy the

process design to accept PDO vessel instrumentation requirements.

2.4.14 Purge Connections and Sampling Points

Sufficient valved connections and vents shall be provided to permit the gas system to be

purged with an inert gas and checked both after erection and for subsequent maintenance.

Purging and test connections shall be valved with blank flanges.

A manually operated sampling point shall be provided upstream and downstream of the

treatment plant.

2.4.15 Material Selection

All materials shall be in accordance with the SP’s and DEP’s. Piping materials shall be in

accordance with the piping classes shown on the PEFS. Alternative specifications shall be

considered only where the specified material is in conflict with the process requirements.

Requirements for low temperature materials on the relief systems shall be reviewed.

All fuel gas pipework between the fuel gas treatment plant and the gas turbine fuel nozzle

shall be 316 SS.

Asbestos materials or gaskets shall not be used.

If a gas containing H2S is to be used, all materials for the fuel gas system shall be selected on

the basis of sour service in accordance with PDO ERD 08-02, Material Selection for Sour

Service, but as a minimum all material in contact with the process medium shall comply with

NACE MR-01-75 latest issue and all process pipework shall use the sour gas piping classes.

Pipeline dust is both corrosive and erosive and can rapidly deteriorate valve seating. Valve

materials for use under these conditions shall be carefully reviewed.

A material selection report shall be prepared to verify the selection of the materials to be

used for the gas treatment plant and pipelines.

2.4.16 Emergency and Process Shut-Down (ESD & PSD) Valves

As a minimum pneumatically operated valves shall be provided in the following locations:

Incoming fuel gas supplies to the gas treatment plant

Downstream of gas treatment plant

Vent valve downstream of gas treatment plant

Condensate return

All the above valves shall be designed to fail in the closed position except the vent valve,

which shall fail in the open position.


30/06/1999 Page 38 SP-1118

Other ESD valves may be required at facilities other than the power plant. These will be

independent of the power plant ESD system but will be connected to the existing ESD logic

at that facility.

All pneumatic actuators shall be selected from the PDO’s list of approved vendors and shall

be with the following features:

Direct coupled position indicator

second closing time

All accessories such as filter regulators, solenoid valves bolted to a stainless steel

mounting plate fixed to the actuator.

Minimum tube size of 3/8" OD. Minimum wall thickness of 0.065 inch for mounting

plate. Larger sizes as required.

Only SWAGELOCK compression fittings to be used.

Actuator shall be without hand wheel

Equipment certified as a minimum for use in a flammable atmosphere, Zone 1 Gas

Group II B, Temperature Class T3, BASEEFA, CENELEC or PTB certifying authorities

only is acceptable.

Ingress protection Class of IP 54 (IEC S29)

Solenoid valve with stainless steel body 3/8" NPTF screwed connections and Viton 'O'

sect/ring seals.

Quick exhaust valve, Pneutrol or equivalent with aluminium body and 3/8" NPTF

screwed connections.

Dust excluder, VERSA type DE-4 or equivalent.

Hermetically sealed snap acting limit switches with type EEX(d) protection.

Norgren or Masoneilan instrument air filters with SS316 filter bowls. Plastic filter

bowls are not acceptable.

The actuator shall be able to hold the ESD valve in its normal position at an air supply

pressure of 450 kPa(g) and be able to withstand the maximum air supply pressure.

Actuators shall be sized to provide sufficient torque to fully stroke the valve against the

specified maximum process differential pressure.

ESD valve actuators shall be sized to provide sufficient torque to fully stroke (open and

close) the valve with maximum process pressure on one side and atmospheric pressure on the

other. The required safety factor between the delivered actuator torque and the required

valve torque shall be as indicated hereafter:

"Actuator design torque" shall be based on new valves (shelf condition), handling non-

lubricating process fluids and shall be equal to the valve torque required for the specified

maximum differential pressure, in addition to the valve static (friction) torque.

"Actuator Operating torque" shall be twice the Actuator design torque.

The "maximum process pressure" is the maximum pressure permitted for that piping class.

The stroking time shall be 3 seconds and is defined as being the time taken between signal

activation and full valve travel position being reached with the corresponding air supply

pressure and with all accessories fitted.

2.4.17 Electrical Equipment Requirements

Due account shall be taken of the hazardous nature of the fuel and shall design all electrical

systems in accordance with the IP Code of practice. All electrical equipment associated with

the fuel treatment plant shall be suitable for installation in a Zone 1 hazardous area. The

hazardous area classification shall be in line with IP Part 15.


SP-1118 Page 39 30/06/1999

2.4.18 Instrumentation and Control

The fuel gas supply and treatment plant shall be provided with all instrumentation and alarms

necessary for unattended, remote, fail safe operation.

All instruments shall be provided with isolating valves, vent and drain connections. Isolation

valves shall allow instruments to be removed from services while the plant is in operation.

Stainless steel tubing shall be used for all instrumentation and control pneumatic lines. PVC

or nylon tubing is not acceptable.

The instrumentation and controls provided on the fuel gas skid shall be either pneumatically

operated or suitable for a Zone 1 hazardous area in accordance with IP Part 15. The use of

the fuel gas as a pneumatic control medium is not permitted. All equipment shall be suitable

for the outdoor environment at station sites. Reliability and minimum maintenance are of

vital importance. Instruments shall be provided with adequate protection, including

sunshades.

All instrument connections shall be provided with MONOFLANGE valves for instrument

isolation.

2.4.19 Vent System

Facilities shall be designed to route the surplus gas and emergency relief to a 'local'

independent vent located inside the Power Station plot.

Interconnection to an existing flare system can be considered only if the operation and

shutdown requirement of the two plants have been studied.

Vent height and sterile area shall be verified by gas dispersion calculations for the gas

turbine units to ensure that there is no risk of a flammable mixture existing beyond the sterile

area or in the case of H2S gases, an unsafe percentage at operator level at any location.

Radiation calculations shall be undertaken to ensure conformance to the SP criteria in the

event that the vent ignites. The minimum vent height shall be 10 metres and the minimum

sterile area radius for the vent shall be 20 metres. These dimensions would have to be

increased if necessary for H2S gas compositions.

2.4.20 Flow Metering and Computation

A fuel gas flow metering unit shall be installed downstream of the filter separators. The unit

shall monitor the fuel gas flow, pressure, temperature and density for eventual computation

of corrected volumetric flow. Transmitters shall be used as the interface between the points

of measurement and the computation rack located on the instrumentation panel within the

control building.

2.5 INSTRUMENT AIR SYSTEM

2.5.1 Instrument Air Package

The instrument air package shall be in accordance with ERD 29-11, and located under a

sunshade.

The capacity of the system shall be determined such as to provide, all compressed/instrument

air requirements for the gas turbines, gas treatment plant, an allowance for system losses and

auxiliary equipment, plus 10% of the total as a contingency.

The package shall be sized for the installation of three gas turbines and all auxiliaries as a

minimum.


30/06/1999 Page 40 SP-1118

For up to and including 3 generating units the pulse cleaning air consumption from only one

gas turbine generator need be considered. For four or more units simultaneous cleaning of

two units shall be considered when determining the capacity of the package.

Power plant instrument air packages are normally classified as non-critical services, and

consequentially only one air drier set need be provided.

The following Instrument air package indications shall be provided on the combined diesel

generator/instrument air package control panel located in the control room:

Low pressure alarm

Compressor temperature high

Compressor inlet pressure low

Differential pressure high

Drier running and alarms

Compressor running/standby/stopped indication

Dewpoint Alarm

The package drain header shall be routed to a soakaway.

2.5.2 Gas Turbine Generator Air Requirements

A connection shall be provided between the Instrument air system and the gas turbine inlet

air filtration system and the generator filtration system. During normal operation of the gas

turbine the connection shall be isolated as the filter cleaning air requirements will be

supplied by “bled air” from the gas turbine compressor. During periods of gas turbine

outage the instrument air system shall be available for filter cleaning.

2.5.3 Instrument Air Distribution Pipework

Where the instrument air system has been sized for a future unit, a branch to supply the

compressed air requirements for the additional gas turbine and its auxiliaries shall be

provided, complete with isolation valve and spectacle blind.

Each take-off point shall be provided with an isolation valve location at the edge of the

equipment skid.

Instrument air piping shall be in accordance with the piping classes given in DEP

31.38.01.11.

2.6 FIRE ALARM AND PROTECTION SYSTEM

2.6.1 General

This section of the Specification covers the fire and flammable gas detection and alarm

system for the gas turbine power plant:

All equipment, other than that forming part of the monitoring and alarm panel and power

supplies, must be suitable for the desert environment and be certified by a nationally

recognised authority.

All systems shall meet the requirements of PDO Specification ERD 88-02 entitled "Fire and

Gas Detection and Protection".

2.6.2 Description and Scope of Work

A fire and gas panel shall be provided. The panel shall be designed and equipped with

adequate spare capacity to accommodate up to 3 gas turbines including all auxiliaries.

The station will be divided into the following Fire Zones as a minimum:-


SP-1118 Page 41 30/06/1999

Fuel Gas skid (One zone per unit)

Emergency Diesel Generator

Individual rooms in the control building (one zone per room)

Gas Turbine unit Auxiliary Control cabin (one zone per unit)

Gas Turbine Enclosure (one zone per unit)

Generator Enclosure (one zone per unit)

Switchyard (if applicable)

Possible additional fire zones may be required if additional plant is installed (such as a

WHRU).

2.6.3 Fire Detectors

2.6.3.1 Combustion (Smoke) Detectors

Combustion (smoke) detectors shall be provided in the following zones.

Gas Turbine Unit Auxiliary Control Cabin

A minimum of 2 detectors in each room of the control building

2.6.3.2 Ultra Violet Detectors

Ultra violet detectors for the gas turbine generators are covered in section 2.2.6.3.

If other separate enclosed areas that are fire risk zones are identified, then a minimum of 4

detectors shall be provided for each of these additional zones. A voting system shall be

employed.

2.6.3.3 Heat Detectors (Fixed Temperature Rate Compensated Type)

The heat detection system shall be designed to act totally independently and as a back-up for

the UV detection system as applicable and shall be provided in the following Zones.

Gas Turbine Generator Enclosure (min. 4)

Gas Treatment plant water bath heaters

All other areas not monitored by the UV detectors.

If other separate compartments that are fire risk zones are provided, then a minimum of 4

detectors shall be provided for these additional compartments.

2.6.4 Combustible Gas Detectors

Gas detectors shall be installed in the discharge ventilation air ductwork of Gas Turbine

Enclosure (min. 3).

If other separate compartments where fuel gas could escape then each associated ventilation

discharge ductwork shall contain a minimum of 3 units.

2.6.5 Manual Break Glass Call Points

Manual call alarm points shall be located at all personnel escape doors, gates and distributed

around the plant.

2.6.6 Automatic Actions and Alarms

i) Detection of a fire in a building shall trip the associated ventilation and/or air

conditioning systems as appropriate.

ii) Detection of combustible gas or fire in any zone shall initiate the station audible alarm

system.


30/06/1999 Page 42 SP-1118

iii) Activation of two UV detectors in the same zone or one heat detector shall initiate

executive action in accordance with Table 3 of PDO Specification ERD 88-02.

iv) Detection of combustible gas within the discharge ventilation air ductwork of Gas

Turbine Enclosure shall initiate executive action in accordance with Table 3 of PDO

Specification ERD 88-02.

v) An automatic CO2 total flooding system shall be installed within the turbine enclosure

and in any other adjacent auxiliary equipment enclosures provided, with the exception of

the generator enclosure. Detection of a fire shall initiate the flood system, which shall

discharge into all protected sections of the enclosure simultaneously. A CO2 activated

alarm shall be provided.

2.6.7 Audible Alarm

A two tone electronic sounders shall be provided in the following zones:

Gas turbine enclosure

Fuel gas treatment plant

All rooms within the control building

Sufficient number of sounders in each location to meet the requirements of ERD 88-02 shall

be provided.

2.6.8 System Monitor and Alarm Panel

The Fire and Gas Panel (FGP) shall be located in the Power Station Control Room.

The capacity of the fire & gas panel shall be such as to incorporate:

Fire zones as detailed in Section 2.6.2 including future requirements

4 off spare zones.

Fire alarm logic shall be executed in solid state or micro-processor system mounted in 19 in.

subracks.

A mimic diagram outlining the site layout and defining the individual zones shall be provided

on the FGP. An LED shall be provided for each separate zone and activation shall indicate a

fire or gas hazard in the particular zone.

Indication of Fire and Gas Panel override facilities shall be provided. A "charge on"

indicating light shall be provided on FGP. A lamp test facility shall be provided.

The power supply and panel layout shall be such as to allow unhindered operation of one gas

turbine unit, while maintenance is being carried out on the equipment in the panel related to

another unit.

2.6.9 Cabling

The fire system detectors and audible alarm units shall be connected to the Fire and Gas

Panel using Pirelli cable type FP200 or equivalent. Cables used externally shall be steel wire

armoured.

2.6.10 Fire Protection and Safety

2.6.10.1 General

Adequate number of fire extinguishers suitable for the plant shall be provided considering

the following list as being minimum requirements:

a) LV Switchgear room 3 off 5.5 kg. Dry powder


SP-1118 Page 43 30/06/1999

b) Control Room 6 off 5.5 kg. Dry powder

c) Unit Gas Treatment Skid/Lube

oil/Air coolers

6 off 12 kg. Dry powder

d) External Transformer 1 off 75 kg. Dry powder trolley

e) Gas Turbine 1 off 75 kg. Dry powder trolley

f) GT Unit Auxiliary control cabin 2 off 5.5 kg. Dry powder or CO2

g) Battery room 2 off 5.5 Kg. Dry powder or CO2

2.6.10.2 Portable Fire Extinguishers

All internal extinguishers used inside buildings shall be wall mounted in the vertical position

and all supporting brackets. Outdoor units shall be mounted on PDO standard design

supports.

Externally mounted extinguishers shall be suitable for the site ambient conditions to which

they are exposed and shall be installed in supporting cubicles.

2.6.10.3 Mobile Trolley Extinguisher

The Unit shall be of the fully tropicalised type and fitted with a sunshade.

2.6.10.4 Resuscitation Unit

A St. John's Ambulance resuscitation unit shall be provided in the LV switchroom. Each unit

shall be mounted on an aluminium base and have both Arabic and English inscriptions.

2.6.10.5 First Aid Box

Two (2) nos. fully equipped first aid boxes shall be provided.

2.6.11 Station Evacuation Alarm

A manually activated evacuation alarm pushbutton shall be provided and shall have the

following features incorporated:

It shall initiate the station audible fire alarm system provided.

The siren shall be silenced manually by an "acknowledge button" or automatically, by a

timing circuit, after 15 minutes.

2.6.12 Interfaces with Other Systems

A common fire alarm signal and CO2 discharged alarm shall be generated within the system

and repeated to the turbine control locally and to the dedicated remote control system to the

Yibal or Marmul control room.

2.7 PAINTING AND SURFACE PROTECTION

2.7.1 General

In general, equipment shall be painted in accordance with ERD 48-01, though manufacturers

painting systems will be considered where indicated.

2.7.2 Control Building and Sunshades


30/06/1999 Page 44 SP-1118

The painting, surface protection and finishes shall be in accordance with PDO standard

requirements for building and civil works. PDO standard colour schemes shall be adhered

to.

Sunshades shall be painted in accordance with PDO standard requirements.

2.7.3 Gas Turbine Generator

The gas turbine and generator and supporting steelwork may be finished in the manufacturers

standard colour scheme provided the paint system is suitable for the ambient and

environmental conditions.

2.7.4 Auxiliary Equipment

Individual standard items of manufacturers equipment, such as the emergency generator and

instrument air compressors may use the manufacturers painting system provided it is suitable

for use in the plant. However, equipment skids, piping, air receivers, etc. shall be painted in

accordance with PDO’s requirements.

2.7.5 Gas Treatment Plant

The complete gas treatment plant shall be painted in accordance with PDO requirements.

2.7.6 Piping

2.7.6.1 Onplot Piping

Onplot buried pipework shall be cathodically protected, where it is required based on the

design.

All pipework shall be protected in accordance with ERD-48-06 and other related DEPs and

SPs.

2.7.6.2 Offplot Piping

All offplot buried pipework shall be cathodically protected. All piping shall be installed in

accordance with pipeline Construction Specification PCS-1.

All pipework shall be protected in accordance with ERD-48-06 and other related DEPs and

SPs.

2.8 ELECTRICAL SYSTEM

2.8.1 General Requirements and Philosophy.

2.8.1.1 Unit System

Each generator shall have a dedicated generator transformer for stepping up the power to

33kV or 132kV as specified in the individual project specification. The generator shall be

connected to the generator transformer through cables or busduct for a current rating up to

2500A and through a busduct for current ratings above 2500A . The type of busduct shall be

subject to approval by PDO.

Each generator shall be provided with a dedicated unit auxiliary transformer and unit

auxiliary LV switchgear . The unit auxiliary transformer shall be connected to the generator

terminals directly.

Each generator shall have a Unit auxiliary control cabin which shall house the following:


SP-1118 Page 45 30/06/1999

The Unit auxiliary LV switchgear

The Unit DC system

2.8.1.2 Station System

The Power station shall be provided with a station auxiliary LV power supply system with 2

X 100% rated station auxiliary transformers. The station auxiliary transformers and the LV

board shall be designed for feeding all the station auxiliary loads for the ultimate

configuration of three units and the auxiliary load of one Gas Turbine generator.

2.8.2 Transformers

2.8.2.1 General

This section covers the requirements of Generator Transformers, Unit, Station Auxiliary

Transformers and the Generator Neutral Earthing Transformers.

For specific requirements of the transformer, the individual project specification shall be

referred.

i) General

The Transformer shall be suitable for outdoor installation in the ambient conditions stated in

this Specification and shall comply with IEC-76 and DEP-33-65-40-31 including the

amendments and supplements to DEP (SP-1117). Generator Neutral Earthing Transformers

shall be housed within the Generator enclosure.

ii) Cooling

The type of cooling shall be ONAN or ONAF. Where an ONAF unit is supplied, the

transformer shall be capable of operating under the ONAN condition up to at least 75% of

full rated load.

Generator Transformer shall be fitted with two coolers or two banks of radiators each

capable of dissipating 50 per cent of the losses at continuous maximum rating.

Failure of one fan in each group of blowers shall not reduce the continuous maximum rating

of the transformer.

2.8.2.2 Continuous Maximum Rating

Transformers shall have the rating stated in Appendix 1 and shall comply with the

requirements as regards temperature rise and overload on all taps irrespective of the direction

of power flow and with the voltage of the lower voltage winding at the normal voltage.

Unit auxiliary transformers shall be rated to carry the full load auxiliary requirements of the

unit plus 25 per cent. The transformer shall be ONAN cooled and may be installed adjacent

to the gas turbine skid.

The Sstation auxiliary transformer shall be rated to carry the maximum of the following loads

in addition to the cool down load of the gas turbine generator and maximum station load of

the station services load plus 25%, with a minimum rating of 1600 kVA.

a) Coasting down/cool down loads, whichever is higher, of two gas turbine generators

Or

b) Start-up loads of one generator plus coasting down/cool downs, which ever is higher, of

one gas turbine

Highest load of either (a) or (b) condition of above shall be taken into account.

Generator transformers shall be rated to carry gas turbine peak load continuously at all

ambient temperatures with a margin of 10% minimum.

Rating of generator neutral earthing transformer (and associated resistor) shall be based on

the following criteria.


30/06/1999 Page 46 SP-1118

The effective neutral resistance as seen from the earthing transformer primary side shall

not be greater than the 1/3 of the total phase to earth capacitance of the generator stator

windings, the LV winding of the Generator transformer and the cables between the

generator and the generator transformer.

The transformer rated primary voltage shall not be less than 1.3 times the generator line

voltage. Rated secondary voltage shall be less than 500V.

The transformer shall be rated for 5 minute duty cycle.

The resistor shall have 10 second rating.

The transformer and resistor shall additionally dissipate losses due to 3rd harmonic

currents.

2.8.2.3 Ability to Withstand Short Circuit

All Transformers shall be capable of withstanding, on any tapping and without damage the

thermal and dynamic effects of external short circuits as per the system fault levels indicated

in Appendix-1 under the conditions stated in IEC 76 part 5.

2.8.2.4 Generator Neutral Earthing Resistor

The neutral earthing resistor shall be of metal grid type with drip proof enclosure giving a

degree of protection of IP21. The framework and enclosure shall be of galvanised steel.

The grids shall be adequately supported on steel rods and porcelain insulators and be

designed to withstand the currents flowing under fault conditions.

Adequate barriers shall be provided to prevent internal flashover.

A removable bolted link shall be provided in the high voltage connection to the resistor for

testing purposes. The link shall be located between the cable box and the resistor. The

neutral earthing resistor shall conform to the requirements of IEEE - 32.

2.8.3 132kV System

The 132kV substation, if applicable, shall be designed as per SP-1113. Switchyard

equipment shall conform to the Company standard SP-1113.

2.8.4 MV/LV Switchgear

2.8.4.1 MV Switchgear(11 & 33kV)

The MV Switchgear and Control gear shall comply with the requirements of DEP

33.67.51.31-Gen. and SP-1120.

2.8.4.2 415V Switchgear

i) General

The 415V switchgear shall comply with DEP 33.67.01.31, PDO SP-1121. The protection

required for switchboards shall be as per PDO Standard drawings SP-1104. In addition

under-voltage protection shall be provided.

In addition for operational reasons, all AC switchboards shall include a common (or

individual per circuit) second stage two-element type no-volt relays with adjustable time

delayed operation for tripping any motor contactor or circuit breaker otherwise left closed

during a sustained failure of supply to the associated AC switchboard.

Separate compartments shall be provided for each function e.g. starter and protective devices

in one compartment. Access to each compartment shall be by separate doors. The motor

circuits shall be in accordance with Shell Standard Drawings S 67004.

ii) Station Auxiliary Board

A 415V Station Auxiliary Switchboard shall be provided for the Power Station. This board

shall supply lighting, ventilation, air conditioning, air compressor and other station loads,


SP-1118 Page 47 30/06/1999

which cannot be assigned uniquely to the gas turbine generator. This board shall have

synchronising facilities to parallel auxiliary diesel generator for load test purposes.

All the incoming and bus coupler breakers shall be provided with facility for momentary

paralleling for live transfer of entire load on to one station auxiliary transformer.

The system shall also provide for detecting the loss of voltage on any generator phase during

running and initiate automatic opening of the Unit auxiliary breaker and closing of the stand

by supply breaker.

During start-up the auxiliary loads of the Gas Turbine generators will be fed from the station

auxiliary LV board. After the Gas Turbine generator reaches a pre-determined speed, the

auxiliary loads shall be transferred to the unit auxiliary transformer through an auto-

changeover scheme. This system shall be on a break before make basis.

iii) 415V A.C. Unit LV Board

The 415V Unit Auxiliary Switchboard shall be used to supply the auxiliary loads associated

uniquely with the gas turbine generator.

It shall be in the form of a floor mounted, metal-clad enclosure, and shall be installed in the

Generator Unit Auxiliary Cabin.

The standby supply breaker (The feeder from the Station auxiliary board) shall be

electrically interlocked with the Unit Auxiliary Transformer secondary breaker such that both

supplies cannot be connected to the Unit LV board at the same time. In addition a voltage

sensing relay with time delay with shall initiate automatic tripping of the standby supply

breaker when the generator has reached a pre determined speed and closing of the Unit

Auxiliary breaker when generator volts are detected on start-up. This system shall be on a

break before make basis.

The relay shall also detect the loss of voltage on any generator phase and initiate automatic

opening of the Unit auxiliary breaker and closing of the stand by supply breaker. Provision

shall be made for changeover of supplies such that all drives shall ride through any

momentary loss of voltage without tripping.

In addition essential instrumentation shall be provided with a safe supply so that no mal-

operation or tripping of the turbine generator shall occur during such transients. Manual

override of the above transfer scheme shall be provided to allow manual transfer from the

Unit Auxiliary Transformer supply to the station supply when the gas turbine is running.

2.8.5 Electrical Motors

All AC and DC motors supplied for the Power station shall comply with the requirements of

DEP 33.66.05.31 & SP-1119.

2.8.6 DC UPS System

2.8.6.1 General

This section covers the general requirements of the DC system.

The system shall comply with the requirements of DEP 33.65.50.31. Specific requirements

of DC system for the Power Station are covered under this section.

The DC System shall include the following:

For each gas turbine unit one 110V (or 125V) DC battery system shall be provided. The

battery system shall comprise 1x 100% batteries, 2 x 100% float & boost chargers and 1

x 100% Distribution Board. The gas turbine unit DC system shall be located in the GT

unit auxiliary cabin.

Two sets of 24V DC batteries (2 x 100% capacity) and 2 x 100% capacity battery

chargers and DC Distribution Board shall be provided for the station auxiliary DC

requirements (Control/relay panels, LV Switchgear, etc.). The station DC system shall

be located in the Power Station Control Building. Where the tie up is at 33kV level with


30/06/1999 Page 48 SP-1118

new 33kV switchgear line up, 110V DC system shall be provided as above instead of

24V DC for the 33kV Switchgear, LV Switchgear and control panels.

Two sets of 48V DC batteries (2 x 100% capacity) and 2 x 100% capacity battery

chargers and DC Distribution Board shall be provided for the Telecommunication

System, where applicable. The DC system shall be located in the Power Station control

building.

The gas turbine DC system shall be capable of supplying the DC supply load, with batteries

fully charged for two abortive starts followed by a successful start, one hour's running and

then a normal shut down (or emergency shut-down if more onerous) of gas turbine

generating set.

The gas turbine battery chargers and ancillary distribution boards and controls shall be

located in the GT Unit auxiliary Cabin. Batteries shall be mounted in adequately ventilated

enclosure in this cabin.

2.8.6.2 Type of Batteries

The batteries shall be of the high performance nickel cadmium pocket plate type complying

with IEC 623. Electrolyte shall be potassium hydroxide conforming to BS 5633.

2.8.6.3 Battery Duties

The rating of each battery shall be determined to meet the requirements of the duty cycle as

under :

Gas Turbine Generator unit dc system - 8 Hours

Station dc system - 8 Hours

Telecommunication DC system - 10 Hours.

Except for the GT unit DC system, all the DC systems shall be designed for the ultimate

configuration of three GTs. GT unit batteries shall be designed for 8 hours duty cycle for

supplying normal load, including emergency lighting load, in addition to the duty described

under section 2.8.6.1. Additionally the batteries shall have a design provision of 25 % of the

capacity for future loads.

2.8.7 AC UPS Systems

UPS systems as described below shall be provided.

An AC UPS system shall be provided at the remote operator station for the dedicated remote

control system, if it is found that the existing facilities are inadequate.

An AC UPS system shall be provided to meet all the AC control supply requirements at the

Power station.

The AC UPS shall comply with DEP 33.65.50.32

2.8.8 Relays

2.8.8.1 General

The electrical protection systems shall be in accordance with PDO Specification, SP-1107

2.8.8.2 Generator Protection

Generator protection schemes shall be as per PDO Specification, SP-1107 and Standard

drawing STD-4-6100-01-3-D.

The Single Line Diagrams show the maximum number of functions that can be grouped in a

single multi-function relay. If the multi-function protection relay can offer more number of

functions in a relay (e.g. LGPG of GEC Alsthom or equivalent), then two relays shall be

offered providing a 100% redundancy.


SP-1118 Page 49 30/06/1999

2.8.8.3 Synchronising Facility

i) Generator Synchronising - Manual

The manual synchronising facility for the generator shall include a synchroscope, check

synchronising relay, double voltmeter, double frequency meter, Synchronisation in progress

lamp and raise/lower controls for voltage and speed.

The synchronism check relays shall include functions to check the voltage, slip and phase

displacement and to allow for either the incoming or running circuits to be dead as may be

necessary to allow full flexibility of normal start-up and emergency operation. A separate

dead bus bar close check relay and/or dead line close check relay, shall be provided and this

shall monitor the condition once the selection is made.

ii) Generator Synchronising - Auto

Automatic synchronising facilities shall be provided for the generator and this when initiated

shall regulate the speed of associated generator prime mover and also adjust the automatic

voltage regulator to obtain the correct incoming generator voltage to match the running

frequency and voltage. When synchronising conditions are correct the equipment shall close

the associated generator circuit breaker. The automatic synchronising relay shall be

supervised with a separate sync. check relay to ensure that the circuit breaker is not closed

due to a wrong permissive signal of a failed auto synchronising relay.

2.8.8.4 Other Protections

All other protection schemes shall be as per PDO Specification, SP-1107.

2.8.9 Cables

2.8.9.1 General

The cables and other accessories shall be as specified in DEP-33-64-10-10-Gen and as

amended by SP-1103.

All HV cables shall be rated such that each conductor and the metal sheath/screen shall be

capable of carrying the maximum fault current expected for 1 second and its final

temperature shall not exceed 250ºC.

Any screening and cable segregation shall be as per the requirements of DEP's 33.64.10.10-

Gen, DEP-32-37.00.31-Gen, & DEP.33.71.00-31-Gen as amended by relevant SP's to

prevent spurious signals being induced into the cables.

2.8.9.2 Cable Installation

Cables, other than those within buildings, shall be laid direct in the ground. All electrical

installation work including cable installation shall be as per PDO Specification document

SP-1099 and DEP 33-64.10.10-GEN and PDO standard drawing SP1105.

2.8.9.3 Instrumentation Cables/Junction Boxes

Instrumentation cables shall be supplied as per PDO Standard ERD 30-03, DEP 32.37.20.10

and ERD 30.01.

Separate junction boxes shall be provided for volt-free signals, SOV signals and 4-20 mA

signals.

2.8.10 Earthing and Lightning Protection System

The earthing system to be provided shall be in accordance with SP-1103, SP-1109, DEP 33-

64.10.10-GEN, SP-1099 and SP-1105 (standard drawings). The earthing of all equipment

and the provision of earthing systems, electrical connections for the outdoor substations shall

be in accordance with the recommendations in the "Guide for Safety in Sub-station

grounding" IEEE No.80 and SP-1113.


30/06/1999 Page 50 SP-1118

2.8.10.1 Lightning Protection

The complete power station shall be adequately protected against lightning using tall masts

generally located around the periphery. No horizontal wires between masts are to be used.

The masts may be used as lighting poles.

Each lightning mast shall have a lightning conductor at the top and be provided with its own

earth electrode connected through a solid down connector, with necessary test points.

The lightning protection system shall be connected to the station earthing system.

The lightning protection system for the entire plant shall be designed as per BS 6651.

2.8.11 Lighting and Small Power System

Lighting and small power system shall be designed to cover all indoor and outdoor

requirements including all plant lighting , perimeter security lighting, roadway lighting,

building lighting and DC emergency lighting. The design shall be as per DEP 33.64.10.10-

Gen and SP-1103. Specific requirements for the Power Stations are covered in this section.

2.8.11.1 Lighting

The type of light fittings and the required illumination levels shall be as per the Table given

below :

AREA TYPE OF

LAMPS

ILLUMINATION LEVEL

REQUIRED(lux)

Normal Emergency

Gas Turbine area Sodium Vapour 25

Gas Turbine Generator

Enclosure

Sodium Vapour 150 10

Roadway Lighting Sodium Vapour 25

Perimeter/Security Lighting Sodium Vapour 10

GT Unit auxiliary cabin Fluorescent 400 40

Fuel handling , storage area

& other areas

Sodium Vapour 25

Gas treatment plant,

Instrument air com-pressor

skid and other aux. systems

skids

Sodium Vapour 150

Control Building Rooms

Control room Fluorescent 500 125

SCADA/Telecom room Fluorescent 500 125

HV Switchgear room Fluorescent 400 100

Battery room Fluorescent 250 25

Office Fluorescent 400 40

Stores Fluorescent 250 25

LV room Fluorescent 300 30

Toilet / passage Fluorescent 100 10

Outdoor lighting shall be controlled by photo-electric cell. Photo-electric cell shall be

suitable for mounting outdoor. A manual bypass shall be provided for the photoelectric

switching circuits.

In the Gas turbine generator skid, each enclosure / compartment or cabinet shall be provided

with a minimum of two fluorescent light fittings controlled from a switch location outside

and adjacent to the enclosure or cabinet main access door. DC powered lighting systems

shall also be provided for standby duty

In Gas turbine generator enclosure, the emergency lamps may be fluorescent or incandescent

types.

2.8.11.2 Convenience Receptacles


SP-1118 Page 51 30/06/1999

Sockets with plugs of rating 30A(TPN) and 60A(TPN) shall be provided at various places in

the Plant area and control building .The sockets shall be distributed in such a way that from

any point the nearest socket shall be accessible within 30M.200A (TPN) sockets with plugs

shall be provided for each Generator Transformer and one near the Station auxiliary

transformer for oil filtration.

15A sockets shall be provided for single phase loads inside the control building.

2.8.11.3 Poles

Lighting poles shall be as per the PDO standard design and drawings SP-1105, Group-1 for

lighting system.

2.8.11.4 Emergency Lighting

The emergency lighting system may be obtained by separate luminaries or normal luminaries

supplied by batteries and arranged to automatically switch on upon mains failure. Self

contained luminaries shall incorporate sealed nickel cadmium batteries with internal charger.

Charging shall take place during periods of normal supply with a recharge period of not more

than 24 hours. The emergency lighting shall provide the required lighting for three hours.

All exits shall be fitted with self contained luminaries and mounted above all doors and

maintained ‘on’ at all times.

2.9 INSTRUMENTATION, CONTROL AND MONITORING SYSTEMS

2.9.1 General

The gas turbine generator shall be suitable for Start-up, shutdown, monitoring and

controlling from the Power Station control building by microprocessor based

turbine/generator control system dedicated for each unit from Yibal OR Marmul Master

Control Centres. In addition, limited control and monitoring facilities are provided through

the electrical SCADA system located at the Yibal and Marmul Master Control centres. The

instrumentation and control system shall be reliable, require minimum maintenance and be

capable of starting (including black start by auxiliary diesel generator), running up to full

speed, synchronising, loading, shutdown (normal and emergency) and preparation for re-start

from the remote control room without personnel in attendance at the Site.

2.9.2 Control and Operation Philosophy

2.9.2.1 General

Facilities for automatic and semi-automatic starting, synchronising, loading and shutting

down of the gas turbine generator unit together with comprehensive supervisory equipment

and alarms shall be provided for the Power Station. Turbine/Generator control system shall

be with triple redundancy facility.

Control shall normally be executed from the Dedicated Remote Control System at Remote

Station (Yibal or Marmul). A shrouded emergency stop red mushroom headed push button

shall be provided adjacent to the Turbine Control System operator interface at the Remote

Station.

Auto/manual synchronising facilities shall be provided for the circuit breakers.

2.9.2.2 Gas Turbine Generator Control

The main logic including the sequencing, should be of electronic design utilising solid state

components / microprocessor based systems mounted in withdrawable circuit cards.

Suitable means shall be provided for testing all control circuits, trip cards, on load including

overspeed, without initiating a machine trip. Provision shall also be included for testing all


30/06/1999 Page 52 SP-1118

trips with the machine running (at no-load) by simulating the trip initiating signal where

necessary.

An electrical protection schemes covering the generator, generator transformer and unit

transformer as shown in the standard drawing shall be located in the Generator Control

Panels/Relay.

Regulated duplicate power supplies shall be provided in the Gas Turbine Control Panel. Fail

safe features shall be provided which shall come into operation in the event of a power

supply failure. No supply failure in a single channel shall cause unit shut down.

The use of timers in the control system shall be avoided wherever possible. Where the use of

timers unavoidable they shall possess inherent fail-safe features.

Protective trip devices shall not be fitted on the emergency dc lubricating oil pumps, or (if

required) dc barring motor. However overload alarm shall be provided. The Gas Turbine

control panel shall be provided with all necessary items to monitor the healthiness of all the

equipment which are required for the safe shutdown of the turbo-generator, but are not

running during normal operation, such that their failure or non-availability initiates an alarm.

The Switchgear/control relay panels shall be provided with all necessary contacts and

terminals for transmitting and receiving the necessary signals for the remote control,

supervision and SCADA facilities.

2.9.2.3 Start-up, Loading and Shutdown

The Turbine/Generator Control equipment shall be capable of effecting set operation as

follows:

Start and automatic run up to minimum governor speed following single manual action

including all necessary interlocks and protection devices for the safe, reliable and

efficient operation of the unit.

Start and automatic run up to synchronous speed, synchronise with other sets (or close

onto a dead system) and load generator (maximum 5%) following single manual action

(an automatic synchronising unit shall be included for the set).

Power turbine speed governor control by manual adjustment and isochronous/droop

selection.

Unit/parallel selection.

AVR datum, MVAR adjustment and AVR/balance/MVAR selection.

Normal controlled shut-down, including gradual off loading and circuit breaker trip

initiation following single manual action.

Emergency trip including circuit breaker trip initiation, following single manual action at

the Turbine control panel or a remote station or a remote automatic trip initiating device.

Compressor cranksoak water wash initiation by single manual action.

Run up to firing speed only without initiating a firing sequence.

Any other facility for safe operation of the plant.

The various facilities for semi automatic operation shall be arranged in a logical manner on

the panel to correspond with the order of the various steps in the starting sequence and the

necessary indications shall be in a logical position relative to the associated controls.

Automatic control of the rate of fuel admission in relation to maximum allowable turbine

inlet temperature and rate of temperature rise during starting and loading shall be provided.

It shall be possible to select base or peak load and rapid or normal start and the controls shall

ensure that the machine is not operated beyond the permitted range.

On automatic synchronising, the unit shall be automatically loaded to 5% of its base load

rating on the closure of the circuit-breaker. Additional loading can be carried out manually,

the necessary facilities being available in the Turbine Control panel and/or via the remote

control system (Dedicated Remote Control System as well as SCADA).


SP-1118 Page 53 30/06/1999

Failure during a start sequence shall be annunciated such that the particular cause of failure is

known.

2.9.2.4 Load Limiting

A maximum load limiting device shall be provided which will override the speed/load

governor and reduce the fuel flow to the combustion system. In order to maintain the mean

turbine exhaust temperature below a set limit determined according to the selected duty (i.e.

either base or peak load).

The limiting device shall operate from a signal derived from the turbine exhaust temperature

and an alarm shall be provided to indicate when the set limit is reached.

Provision shall be made in the design to facilitate the checking of temperature signal as

sensed by the load limiter.

If, in addition to the limiting parameter of turbine exhaust temperature any other parameters

requires limiting at any operating condition, the necessary limiting device shall be provided

together with an alarm to indicate that it is in operation.

The gas turbine shall automatically switch to peak load operation on falling frequency. This

shall be alarmed to remote. Also an override for this facility shall be provided.

2.9.2.5 Alarm and Trip Annunciations

A turbine alarm and trip annunciation scheme shall be designed and provided such that

specified alarms and trips, and all others which are necessary or considered desirable for the

safe and efficient operation of the plant shall be included.

All the necessary equipment shall be provided so that alarms and trip indications, shall be

repeated to the Dedicated Remote Control System and SCADA system. The local alarm

reset facility shall also cancel the remote alarms where applicable. The audible alarm on the

Generator Control and shall be operative only when the unit is under local control.

Alarm and trip initiating devices and systems shall be segregated from control circuits.

The equipment provided shall be capable of accepting either "fleeting" or "maintained"

initiation signals with provision for changeover to either.

For the purposes of the annunciation scheme the various fault conditions shall be grouped

into the following categories:-

Trip indicates shut down on fault condition

Pre-Alarm to indicate a fault condition, which, if corrective action is not taken will result

in a shutdown.

The first level shall initiate a category (b) Alarm followed by a category (a) Alarm and Trip.

In the event of a mechanical trip the system shall be designed so as to trip the unit shutdown

valve.

First-up facilities for fault diagnosis are required.

2.9.3 Gas Turbine Generator Instrumentation

The gas turbine instrumentation is to be reliable, of high quality, suitable for the outdoor,

remote location of the Site. All items of instrumentation are to be rated for the full ambient

temperature range and suitably protected by cooling air and/or sunshades. All

instrumentation is to be located to provide easy access for maintenance. Each item

interfacing with the process shall be supplied with isolating valves and/or manifolds,

arranged for easy connection of test instruments for calibration. Instrument mountings

should be designed so that removal and replacement can be accomplished in minimum time.

Instrument locations should be arranged so that testing and calibration can be performed

without having to shutdown the machine.

Vibration monitoring of the machine bearings shall be measured in both horizontal and

vertical planes. This shall be selected from the PDO’s approved vendor list and shall be used


30/06/1999 Page 54 SP-1118

for protection of the train. Intrinsic safety philosophy shall be implemented with Pepperl +

FUCHS galvanic isolation barriers type ICHD3-1vR/EX126 Part No. 71661.

Calibration and testing of instruments shall be carried out according to DEP's 62.10.08.11

and 62.10.09.11

Generator control panel and Turbine control Speedtronic Mark V control system or

equivalent shall be an integral part of the equipment used during factory acceptance tests of

the gas turbine unit.

All instrumentation shall be in accordance with latest revision of the following PDO SP’s

and Shell DEP’s referred in section 1.2.1 and 1.2.2 respectively.

The inspection and testing shall be in accordance with the DEP’s referred in section 1.2.2

2.9.4 Generator Control Panel

The Generator shall be provided with its own self-contained protection, instrumentation,

monitoring, synchronisation and excitation control system. The Control Panel shall be

mounted adjacent to the Turbine control Panel and shall be identical in general style and

size. The panels shall cover all requirements for local control and monitoring of each gas

turbine generator set.

The front of panel equipment shall include the following:

Auto start and stop - pushbutton

Manual start and stop - pushbutton

Emergency trip-pushbutton (shrouded).

Compressor clean start-pushbutton

Control supply isolating switch

Manual/auto/no-load/selector switch

Key operated electrical override

Manual excitation on - pushbutton

Excitation raise/lower - switch

AVR null balance meter

Base/peak operation selector switch.

Rapid/normal start selector switch.

Synchronising selector switch auto/manual/dead bus close.

Generator Circuit breaker close/neutral/trip control switch.

Synchronising instruments. (synchroscope, dual voltage/dual frequency meter.)

Indications, alarms and metering

At least 10% spare panel space shall be available and be evenly distributed over the panel

face.

2.9.5 Dedicated Remote Control System

Full control and diagnostic facilities shall be assured by incorporating the gas turbine on the

Dedicated Remote Control System. While ‘GE’ make ‘SMART REMOTE’ has been used as

the Dedicated Remote Control System for the existing facilities in North Oman, DMACS

system is being used as the Dedicated Remote Control System for the existing facilities in

South Oman. The facilities to be provided for the gas turbine generator on the Dedicated

Remote Control System shall be at least equivalent to the existing system The controls to be

provided shall include :

Auto start and stop.

Emergency trip

Base/peak operation selection

Rapid start selection


SP-1118 Page 55 30/06/1999

Excitation raise/lower

Load raise/lower

Synchronising selector switch inhibit release

Generator Circuit Breaker control

Auto-manual dead bar-off indicates synchronising mode selection.

Select isochronous or droop mode

The information for remote control of the machine via Dedicated Remote Control System

shall have to be transferred between the Power Station and the remote control room through

the microwave system.

2.9.5.1 Mimic

The existing remote control room mimics at Yibal or Marmul shall be modified to reflect the

changes in the system. The modification shall utilise similar materials to the existing

equipment, so that the modifications shall appear as an integral part of the existing facilities

in style, colour and size.

2.9.5.1i) Dynamic Mimic

The existing dynamic mimic shall be extended and shall include the following facilities:

MW power flow in the lines

Load on each machine

Frequency of the machine

PS station common alarm indication

ii) Static Mimic

The existing static mimic shall be extended to cover the system expansion. This is an artwork

modification only.

2.9.6 SCADA

Power Station shall be provided with a new SCADA system where there is no SCADA

already existing or else extension of the existing SCADA system shall be made.

The SCADA system shall fully comply with SP-1116.

Transmitting of SCADA signals from the Power Station to the remote control room shall be

via two alternative routes formed with a combination of PLCC, microwave and fibre optic

systems.

2.9.7 Metering

Energy flows from each generator and each outgoing feeder to PS auxiliary system shall have

to be measured at the PS by precision (“Commercial Billing”) grade energy meters. The

energy meters shall be provided with pulse transmitting contacts for SCADA.

Check metering facility (duplication of meters) is generally not required. However, all the

metering CT and VT shall be designed (burdens) such that check metering facility can be

added at a later date.

2.10 EMERGENCY SHUTDOWN SYSTEM

2.10.1 General

The Station safeguarding system shall be designed for high integrity and unmanned

operation.


30/06/1999 Page 56 SP-1118

The safe shutdown of equipment in an emergency shall be evaluated against the need to

maintain high electrical availability therefore, a total station ESD is to be considered in only

the most serious incidence. Preference will be given to Process Shutdown (PSD's).

It is proposed that an ESD of the total facility can only be manually initiated. The ESD can

be activated from either the power plant or remote control centres (Yibal or Marmul).

PSD's can be activated automatically or manually.

When an installation is extended with additional unit, the safe-guarding system of the old and

new unit shall be integrated and a combined cause and effect drawing shall be made.

2.10.2 PSD

The GT 'process train' in terms of a PSD, includes the associated gas treatment plant,

generator transformer and switchgear

In the event a PSD of one gas turbine train shutting down, the following should occur :-

Gas Treatment plant ESDVs would close isolating and depressurising the gas system.

GT would trip and Generator breaker open.

If a PSD was initiated by a fire alarm then automatic fire protection systems, where provided,

should activate in the alarmed fire zone.

The tripping of the gas turbine or electrical system should not automatically result in the

depressurisation of the gas treatment plant. Only an emergency shutdown or fire in the gas

turbine or associated electrical equipment should cause the gas system to depressurise.

2.10.3 ESD

An ESD would result in all PSD areas activating.

2.10.4 Resetting After A PSD Or ESD

It shall not be possible to reset the ESD or PSD systems and valves remotely from any

location. The operator is required to go to the site and confirm that the plant is safe before

locally resetting the PSD or ESD systems.

2.11 ENVIRONMENTAL CONSIDERATIONS

The Company is required to submit an Environmental Impact Statement (EIS) for new power

plants and extensions to existing plants. The Company will submit an EIS to Ministry of

Regional Municipalities & Environment (MRME) who will issue an Environmental Permit

with a list of requirements. These requirements are to be strictly complied with.

Key issues will be SO2 ground level concentrations, releases of compounds to the

atmosphere and disposal of wastes. The Company has standardised on a minimum gas

turbine stack height of 15 metres for 30 MW gas turbines. This aspect shall be critically

reviewed by the supplier. The use of low NOX gas turbine combustion systems is mandatory.

2.12 CIVIL WORKS

All civil works shall be as per the relevant SPs and DEPs listed under Clause 1.2.1.


SP-1118 Page 57 30/06/1999

APPENDIX 1 : STANDARD DRAWINGS

STD-1-1700-001-1-0 - Power Station - PEFS Knock Out Vessel/Strainer

STD-1-1700-002-1-0 - Power Station - PEFS Electric Water Bath Heater

STD-1-1700-003-1-0 - Power Station - PEFS Pressure Reduction Skid

STD-1-1700-004-1-0 - Power Station - PEFS Filter Separator Skid

STD-1-1700-005-1-0 - Power Station - PEFS Metering Skid

STD-1-1700-006-1-0 - Power Station - PEFS Condensate Drain Vessel

STD-1-1701-001-1-0 - Power Station - UEFS Instrument Air System



STD-1-1701-004-1-0 - Power Station - UEFS Auxiliary Generator Fuel System

STD-1-1701-005-1-0 - Power Station - UEFS Make Up Water System

STD-1-1702-001-1-0 - Power Station - PFS Fuel Gas Treatment Plant

STD-3-1800-001-1-0 - Power Station - Site Layout

STD-4-2310-001-1-0 - Power Station - Key Single Line Diagram

STD-4-2311-001-1-0 - Power Station - Equipment Layout Control Building (Alternative - 1)

STD-4-2311-002-1-0 - Power Station - Equipment Layout Control Building (Alternative - 2)

STD-4-2312-001-1-0 - Power Station - Area Layout Classification


30/06/1999 Page 58 SP-1118

APPENDIX A : GLOSSARY OF DEFINITIONS, TERMS AND ABBREVIATIONS

The following terms and abbreviations used in this document, are defined below:

General Terminology

Shall - The word 'shall' is to be understood as mandatory.

Should - The word 'should' is to be understood as strongly recommended.

May - The word 'may' is to be understood as indicating a possible course of

action.

The Company - Petroleum Development Oman L.L.C. Muscat, Sultanate of Oman.

User - A specified engineer or Consultant who applies these Standards in the

execution of PDO project.

The Company -

Representative

A person appointed from time to time by the Company, having the

functions set forth in Article 2 of General Conditions for Construction

Works, and whose authority shall be notified in writing to the Contractor

by the Company.

The Consultant - The party to the contract with the Company who is responsible for

providing the design, engineering and other related consultancy services

under the contract.

The Contractor - The party to the Contract with the Company who is responsible for the

construction and other related works specified in the contract. On

occasion, for example in 'EPC contracts' the contractor may be responsible

for design, engineering, manufacture, shipment, supply, installation,

testing, commissioning and performance guarantee up to the defects

liability period as defined in the individual contract.

Manufacturer - The party responsible for the manufacture of equipment and services to

perform the duties specified by the Consultant or Company.

Vendor/Supplier - A party responsible for the supply of equipment, materials or product-

related services in accordance with the Purchase Order issued by PDO or

its nominated Purchasing Office.

Works - All Works to be executed and all services to be rendered by a Contractor

under the terms of a Contract.

Worksite - A defined place designated by the Company whereat all Works and

services shall be executed by a Contractor under a Contract.

Abbreviation

AC - Alternating Current.

API - American Petroleum Institute

AVR - Automatic Voltage Regulator

BS - British Standard

DC - Direct Current.

DEP - Design and Engineering Practice

EPC - Engineering, Procurement and Construction

ERA - Electrical Research Association.

ERD - Engineering Reference Document (old revision of SP).


SP-1118 Page 59 30/06/1999

GCP - Generator Control Panel

HP - High Pressure

HV - High Voltage.

IEC - International Electrotechnical Commissions.

IEE - Institution of Electrical Engineers (UK).

IP - Institute of Petroleum (UK).

Ipxx - Degree of protection of enclosures as defined in IEC 529.

LP - Low Pressure

LV - Low Voltage.

PDO - Petroleum Development Oman LLC.

PF - Power Factor

PLCC - Power Line Carrier Communication

PVC - Poly Vinyl Chloride.

SCADA - Supervisory Control And Data Acquisition

SIEP - Shell International Exploration and Production B.V.

SIOP - Shell International Oil Products B.V.

SP - Specification(PDO)

UV - ultra violet

VAR - Volt Ampere Reactive

WHRU - Waste Heat Recovery Unit


30/06/1999 Page 60 SP-1118

SP USER-COMMENT FORM

SP User-Comment Form

If you find something that is incorrect, ambiguous or could be better in an SP, write your comments

and suggestions on this form. Send the form to the Document Control Section (DCS). They make a

record of your comment and send the form to the correct CFDH. The form has spaces for your

personal details. This lets DCS or the CFDH ask you about your comments and tell you about the

decision.

SP Details Title Issue Date:

Number:

Page number: Heading Number: Figure Number:

Comments:

Suggestions:

User’s personal details

Name:

Ref. Ind: Signature: Date:

Phone:

Document Control Section Actions

Comment Number: Dates CFDH

Ref. Ind: Recd: To CFDH:

CFDH Actions

Recd

Date:

Decision:

Reject:

Accept, revise at next issue:

Accept, issue temporary amendment

Inits: Ref.

Ind:

Date:

Comments:

Originator

Advised:

Date: Inits: Document Control

Section Advised:

Date: Inits:

Documents

Specification for Power Station - Lankaneth-pawanlankaneth-pawan.com/wp-content/uploads/2016/07/O-12...Specification for Power Station Version 1.0 SP-1118 Page 7 30/06/1999 OP12 Preparation