(pec tender no.: 100/2007) - china-power-contractor.cn turbineauxiliaries.pdf · 1.4.0...

FICHTNER Volume - III Project Subject Tender Doc. No. Rev Section

REPUBLIC OF YEMEN TENDER DOCUMENT FOR 1.0 PEC – ME ENGINEERING, PROCUREMENT & 7195-GE-SPC-700-001 BC Sheet No.

400 MW MARIB GTPS – II CONSTRUCTION (EPC) 1

Sec-1 Gas Turbine & auxiliaries_ReBid APM/ME 6/3/07

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(PEC TENDER NO.: 100/2007)

VOLUME - III SECTION 1.0

GAS TURBINE & AUXILIARIES





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(PEC TENDER NO.: 100/2007)

Table of Contents

1.0.0 GAS TURBINE & AUXILIARIES SYSTEM...............................................................................3

1.1.0 GENERAL.................................................................................................................................3

1.2.0 SCOPE OF SUPPLY................................................................................................................3

1.3.0 TECHNICAL REQUIREMENTS ...............................................................................................5

1.4.0 MAINTENANCE/INSPECTION REQUIREMENTS OF GTG & AUXILIARIES .....................34

1.5.0 DOCUMENT/DRAWINGS TO BE SUBMITTED ALONG WITH THE BID.............................34

1.6.0 SPECIFIED DESIGN DATA ...................................................................................................36

1.7.0 GUARANTEES, REJECTION ................................................................................................41

1.8.0 TECHNICAL DATA BY THE TENDERER..............................................................................42





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1.0.0 GAS TURBINE & AUXILIARIES SYSTEM

1.1.0 GENERAL

This specification includes the Design, Manufacture, Supply, Erection, Testing & Commissioning of Four (4) no. Gas Turbine & its Auxiliaries system. The proposed Gas turbine & auxiliaries shall be designed as per the design criteria and material specification given in this specification and shall be new and unused. If any provision of the specification departs from the Tenderer’s usual construction sufficiently to materially increase the cost of the equipment without in his opinion, providing corresponding increase in quality/reliability or if he considers that his standard construction would provide better quality/reliability, he shall offer the equipment/system on the basis of his standard construction. In case such offer is made, the Tenderer shall state very clearly the merits of his offer and the demerits, (in his opinion) the specified equipment/system has, and the deviations taken against the specification are to be clearly stated in the “Deviation Schedule” without which it will be considered that the Tenderer complies to the specification requirements. However, the Tenderer shall not make any changes on the offered equipment during execution.

1.2.0 SCOPE OF SUPPLY This section sets out the scope of the installations covered by this specification as well as required supplies and services, but without excluding other necessary components and services not mentioned.

1.2.1 Gas turbine

Each Gas turbine generator unit shall be complete with the following equipment The air intake system shall be provided with one stage dry system using high efficiency

reverse pulse jet type self cleaning filter system, plenum chamber, silencer, expansion joints, ducts and supports. The compressed air requirement of intake air filter shall be met by either GT bleed air or by providing skid mounted air processing unit if required.

Air compressor with anti-surge system

The lube oil system shall be in accordance with manufacturer’s standard specification/design and normally includes main oil pump, auxiliary oil pump, emergency oil pump, control oil pump, oil coolers, filters, oil tank (complete with vents, extraction fans, drain, fill line), controls, interlocks and instrumentation alarms. The system shall be designed to cater to the GT requirement during normal operation/ emergency trip/shutdown and coast off as well as during start-up condition.

Inlet guide vane system

Fuel combustion system complete with ignition system with burners designed for NOx abatement meeting emission norms as indicated in Vol-II, Cl. 16.2.5.

The cooling water for the GT lube oil cooler, generator air cooler and control oil cooler (if required) shall be catered by CCW system.

Starting system consisting of SFC or starting motor with auxiliaries and shut down system.

Accessory drive gearbox

Exhaust frame blower & motors





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Atomising air pre-cooler, Atomising air manifold, with necessary controls. All combustion and atomizing air to be taken from GT compressor. The main compressors shall also provide full pressure boost at initial start.

Mounting System

Barring facilities as per Manufacturers own design comprising of either Turning Gear system with an a.c. drive, or an Auxiliary Hydraulic Ratchet System. Provision of manually turning the turbine generator shall be available.

One (1) number on-line / off line compressor water wash system comprising of detergent & DM water tank, heaters, motor driven wash pump, motor driven detergent pump, interconnecting SS piping, etc. The water wash system shall be skid mounted & shall be provided with a weatherproof enclosure.

Drain system with dirty oil drain collection tank, associated pipe work and transfer pump.

Bolt tightening system either hydraulic or electric heating element type.

Turbine shell & exhaust frame cooling system

Machinery equipment unit enclosures with insulation and ventilation, interior lighting etc suitable for outdoor installation.

Integral Fire Detection & Protection System for the turbine enclosures.

Closed Cooling water system interconnecting piping, valves etc.,

Gas Turbine exhaust gas ducts with expansion joints, silencer and exhaust stack of 30 m minimum height.

1.2.2 Common equipment and services

- All controls, measuring and monitoring equipment, to an extent at least in accordance with the corresponding descriptions of section 9.0 of Volume V and additional instrumentation necessary for matching to specific designs of equipment and units.

- Necessary drain tanks, interconnection piping instruments, controls etc. - All necessary pipe work fittings, expansion joints, valves, automatic actuators, safety

devices, fastenings, etc. - Foundations anchor tools, spring guides, embedded parts, base frame, bed plates, sole

plates, shims, packers, supports, etc. for all equipment. - All necessary insulation as required in Section 7.7 of Vol. IV. - All necessary painting, corrosion protection and preservation measures as required in

Section 7.6 of Vol. IV. - Complete detailed labeling of all installations as required in Section 13.0 of Vol. II - Documentation according to Section 12.0 of Vol. II - All necessary service platforms, stairs, ladders, for the complete Gas turbine generator

area, together with all auxiliary equipment. - All necessary noise prevention measures as required in `General Technical

Specification’. - All necessary couplings and coupling guards





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- All necessary venting, draining and emptying equipment - All necessary safety measures - One set of special tools, tackles and equipment as per section 11.0 of Vol. II - Complete electrical system including drive motors suitable for area specified, control

panel, local push button stations, transformer rectifier set, power & control cables, cabling complete with supports, cable trays, glands, lugs, for the successful operation of the plant. The electrical system shall conform to the requirements specified in Section 8.0 of Vol. V

- Spare parts according to section 10.0 of Vol. II - All consumables as per section 3.0 of Vol. II . - Tapping points complete with isolation and all necessary instruments for performance

guarantee testing. - All standard equipment and accessories normally included in the supply schedule but not

separately listed.

1.3.0 TECHNICAL REQUIREMENTS 1.3.1 General

The requirements indicated in this specification is for each Gas Turbine Generator unless otherwise exclusively specified.

The gas turbine shall be of heavy duty, industrial type suitable for outdoor installation with a

sound attenuation, weatherproof enclosure, directly coupled to a 50 Hz generator. The alternating current electrical generator shall be directly coupled to the gas turbine. The gas turbine shall be capable of firing both Natural Gas and Distillate Oil. The Natural

Gas will be the primary fuel and Distillate oil will be the standby fuel. All major components namely the gas turbine, auxiliary components, generator and other

major critical systems included in the gas turbine package shall be required to undergo acceptance test-run at the manufacturers works prior to delivery at site.

The Tenderer shall in the design of essential auxiliary systems refer to appropriate electrical specification to ensure that the source of power supplies is consistent with the philosophy of providing a reliable AC supply and safe DC sources to ensure safe start-up operation and shutdown of the unit under any conditions.

The Tenderer shall design the gas turbine proper and its auxiliaries using his good

engineering practice and proven experience, in order to obtain good and reliable equipment having superior performance. No prototype equipment or components shall be used. The technical lifetime of gas turbine plant shall not be less than 25 years

All accessories, cables, piping, protection and safety equipment and auxiliaries normally

belonging to a package unit required for safe and continuous operation, even if not specifically mentioned shall be included.





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The Tenderer shall offer a plant complete with all parts and details, functional and operational under Site conditions, designed and manufactured with good engineering practice and to international standards.

The gas turbine shall have minimum number of bearings and shall be located on a steel

frame with adequate steel structures and concrete foundations and all bearings to be easily accessible.

Accessibility and Ease of Maintenance Considerable importance will be placed on the ease with which maintenance and servicing can be carried out on all equipment. It shall be possible to remove and replace such sections of the enclosures as are necessary to undertake maintenance with the minimum of disturbance to other equipment. The Contractor shall therefore provide comprehensive and fully detailed information on this subject suitably illustrated with diagrams and drawings.

In particular, the recommended procedures for carrying out the following operations shall be described:

(a) removal of the turbine/compressor rotor and generator rotor

(b) replacement of all combustion chamber linings

(c) replacement of air intake filters elements

(d) removal of all casings

All lifting equipment and runway beams necessary to remove the equipment for maintenance shall be provided.

1.3.2 Foundation The gas turbine, generator and all directly coupled auxiliaries shall be installed on one

common foundation. 1.3.3 Air compressor The gas turbine air compressor shall be sufficiently flexible aerodynamically to permit normal

operation of the turbine generator unit without any tendency to surge such that it is unconditionally stable at all loads, during load changes, during run-up and shut-down, and overspeed. The rotor is to be statically and dynamically balanced and overspeed tested at the factory.

In order to enhance the high efficiency at part load in simple cycle and combined cycle mode,

variable geometry inlet guide vane shall be installed as part of the gas turbine main component.

If any device is provided for control of compressor surge and/or exhaust temperature control

by virtue of air flow control, they shall be of proven design and independent of external supplies. Full details of the system shall be stated in the Bid. Performance details of the compressor shall be given to indicate the margin provided against surge under operating conditions.

Tap-off's shall be provided to supply air required for sealing of gas turbine glands, bearings

and for cooling of the combustor nozzles & turbine blades, cleaning of air filters.





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The materials and coating of the compressor stationary and rotating blades shall be chosen

to be suitable for continuous operation in the site climatic conditions. The air path of the compressor including rotor, blades, and housing shall be protected by suitable and adequate coating. The materials and coating used shall be stated in the Bid.

Provision shall be made for accurately measuring the mean compressor delivery temperature

and static delivery pressure with test instruments. Borescope holes shall be located in the compressor section to facilitate usual inspection.

1.3.4 Combustion System The gas turbine units shall be dual fuel and designed to fire the specified gas fuel or liquid fuel

oils as specified. Gas Turbine Generators are to be operated with natural gas as primary fuel and distillate oil as back-up fuel.

The design of the combustion system shall be such that an even temperature distribution is

provided at the turbine inlet. The normal and maximum limits of temperature scatter (spread) at the turbine inlet and its

control shall be stated in the Bid. The corresponding temperature limits shall be given at the normal temperature measuring points.

The burners shall be of the 'smokeless' design capable of efficient atomization and stable

combustion at all loads and to meet current allowable emission limits. Combustion efficiency shall be sufficiently high to ensure the exhaust emissions complied

with the requirement of "Specified Design Data" Tenderer shall not elevate the firing temperature solely for the purpose of obtaining higher

efficiency, without due consideration of exhaust emission limitation and long operating life of 'hot gas path' components.

The exhaust gas shall be (during transient as well as steady state operation including full speed

no load operation and change over from one to another fuel) as clear as possible, whereby the degree of smoke intensity, specified by smoke spot number shall not exceed the following limits :

Bacharach Smoke Spot No. 1 (Definitions see ASTM D 156 - 65)

A reliable flame supervisory system shall be provided to detect the presence of a flame in the

combustion chamber based upon two out of three redundancy system. This system in principle shall employ three sensing elements through three separate channels, with atleast two channels detecting the absence of the flame to trigger the trip. Any one channel shall detect absence of the flame and shall initiate an alarm for immediate action.

If the gas turbine is having more than one combustion chamber without any inter-connection,

the redundancy system shall be fitted to each chamber. Where multi-chambers are cross-connected the three supervisory elements shall be fitted to different combustion chambers. Inspection windows, or the facility for inspection equipment shall be provided and the method stated in the Bid.





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The combustion system shall be of suitable material and designed to withstand the internal pressures and temperatures. Thermal barrier coatings may be applied to the inner walls of the combustion liners in order to obtain longer inspection intervals. For turbines with multi chambers, transition pieces (which conduct the combustion gases to the hoist stage turbine nozzle) shall be cooled by air from compressor discharge. The materials of construction of the combustion system shall be stated in the Bid.

The ignition system shall preferably utilize high energy igniters and for combustion systems

with cross tube connections at least two igniters shall be provided diametrically opposed. For combustion chambers with no cross connections at least one igniter per chamber shall be provided.

The combustion system shall be of robust long life design, suitable for continuous operation

at base load on Natural Gas. Provision shall be made for reliable purging of the burner system to prevent combustion

explosion as well as choking of the nozzles. Attention shall also be given to the need for gas fuel leakage detection system.

The enclosure in which combustion chambers are located must adequately be ventilated so

as to avoid the production of fuel vapour and risk of explosion in case of fuel leakage. The Tenderer shall describe this feature in detail in his proposal.

Teflon seated ball valves shall be provided for isolating valves in the fuel system. The ball

valves shall be designed and manufactured to meet the requirements of API 607 for fire safe valves.

1.3.5 Turbine The turbine rotor shall be of proven multi-stage, axial flow type design. The gas turbine shall be of proven design using manufacturers standard equipment where

applicable to ensure maximum plant reliability, standardization of components, and early delivery in the planned time scale.

The gas turbine shall be suitable for operation under severe tropical conditions with extremely

high air temperature and humidity and to meet the turbine components life/maintenance guarantees with the operating regime identified with the gas turbine fired on natural gas.

The gas turbine shall preferably be of split casing construction for convenience in

maintenance and shall permit easy access to blading inspection and fittings without undue difficulties. Suitable guides shall be provided where necessary, to prevent damage to the blading while raising or lowering the upper portion of the casings.

Where rotors are joined together (e.g bolted) a detailed description and reasons of the

method shall be included in the Bid stating how alignment is maintained under differential thermal conditions. Where rotor parts are welded together a detailed description of the welding procedure shall be included in the Bid.

The rotor design shall allow changing of blading without the need of rebalancing the rotor.

The method of attaching and replacing the blades (including special tools and skill required) to the rotors, shall be stated in the Bid.

The turbine blading offered shall have been fully proven for expected guaranteed running

hours at the turbine inlet temperature specified. The manner of blade cooling for stationary and moving blades shall be stated together with a description of the cooling system





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arrangement. If any external cooling pipes are used adequate drainage arrangements shall be installed where necessary.

The turbine casings, 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 and blading shall withstand, without premature failure, the thermal shock

associated with repeated starting, loading and rapid load changes. Any limitations on plant offered shall be stated in the Bid.

All the parting plane bolts in the gas turbine casings shall be designed for opening with hydraulic tools. Design with heating shall not be allowed.

Where jacking bolts and jacking guides are recommended by the gas turbine manufacturer for use in lifting/removing casing sections then this equipment shall be provided under this contract.

The factor of safety for the turbine disc and blades based on the disc and blade stresses

applicable to an overspeed of 20% in the fully heat soaked condition at the design full load shall be stated in the Bid.

The stationary and rotating blades shall be coated with appropriate high temperature

protective layer, which shall reduce the attack of corrosive gases and products of combustion. The Tenderer shall indicate the number of stages which are coated and shall describe the type of protective layer (coat) or other protective means.

Inspection equipment and facilities including suitable plugged openings shall be provided to

examine the compressor-turbine stationary and rotating blading with minimum disassembly and without the need to open the casing or lifting the rotor. The internal inspection facilities and tools/equipment shall be stated in the Bid.

The materials of construction for the rotors and stationary and moving blades shall be stated

in the Bid.

Antisieze compound shall be used on initial build of all nuts, bolts, studs and location dowels etc.,

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

provided and shall be capable of identifying any imbalance in temperature distribution. Thermocouples including the junction box shall be suitably located where they will not malfunction and to permit easy accessibility by the maintenance personnel.

1.3.6 Compressor Blade Cleaning Equipment Suitable and proven equipment for on-line and off-line blade cleaning shall be provided for the

compressor blading without the necessity for opening up or dismantling any part of the machine. It shall be the Tenderer's responsibility to devise a suitable cleaning technique to suit the anticipated type of fouling which will be encountered at Site. If, during the warranty period, it is found that the cleaning systems supplied are ineffective, the Tenderer shall make any necessary modifications or change the method of cleaning at no extra charge.

The cleaning procedures provided shall be operable only by manual initiation. Sufficient storage tanks or bins to hold the cleaning medium to achieve one complete

cleaning cycle shall be provided. Storage tanks or bins shall be located to be easily





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accessible for topping up the cleaning medium. The storage tanks, heater, piping, etc shall be of stainless steel construction.

The Tenderer shall supply cleaning medium upto one (1) month after taking over of the plant

in well packed drums to allow proper storage. The Tenderer shall state if the cleaning medium is locally available.

The margin of performance deterioration that the machine will accept before a cleaning cycle

is deemed necessary shall be stated in the Bid. The method used to ascertain this margin shall be stated in the Bid (e.g compressor delivery pressure, power output with respect to turbine exhaust temperature).

The effluent formed during cleaning shall be piped to the nearby sump from where it shall be

suitably disposed. Accessory Gear (Wherever Applicable)

If any accessory gear drive is provided to transmit power from the main turbine rotor to turbine accessories, the gear box design shall comply with requirements of API 613 or equivalent recognised National / International Standard and to the highest short-circuit loading. Removable guards and shields shall be provided to protect personnel from the accessory gear and rotating shafts and warming signs installed.

1.3.7 Mounting System The mounting system of the gas turbine casing onto the foundation shall take full account of

vibration and thermal expansion of the unit. Details of the method used to locate the fixed point of the turbine casing in relation to the rotor

thrust bearing and the provision for accommodating thermal expansion of the casing and maintaining rotor alignment without producing detrimental stresses shall be stated in the Bid.

If lubrication or gasket or cooling system is required between moving surfaces, the materials

of the contacting surfaces and the method of lubrication, the gasket type, and the cooling system shall be stated in the Bid.

If any of the turbine generator supports require cooling, the equipment and the cooling

arrangement and means of monitoring shall be described in the Bid. Care shall be taken to ensure that radiant heat from the turbine exhaust casing does not

adversely affect the mechanical integrity of the concrete foundation structure. The turbine shell & exhaust frame compartment shall be cooled using two nos. 100% capacity blowers, if required.

1.3.8 Piping The gas turbine generator unit shall be provided with a complete system of high quality, non-

corroding and heat resistant piping integral to, or between, components furnished by the Tenderer.

Piping shall include all high point vents, low point drains, instrument piping, insulation,

hangers, and other piping accessories required for a complete system. All piping shall be factory mounted on the unit to the extent possible.





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All piping shall be routed so as to be within the confines of the gas turbine generator

enclosure whenever possible. A minimum of 2,500 mm head room clearance is desired over walkways and access areas. All flanges shall be easily accessible and pipes divided into manageable portions for handling.

All piping shall be neatly arranged to be as inconspicuous as possible and shall offer minimal

obstruction while being easily supported and drained. 1.3.9 Bearings and Glands Hydrodynamic horizontally split radial bearings of the precision bore sleeve or multi-pad type

with steel backed white metal replaceable sleeves or pads shall be provided for each main shaft bearing. The bearings shall be arranged so that they are adjustable and readily accessible and the lower halves can be removed and replaced without lifting the rotor more than the minimum allowable internal vertical clearance.

The bearing design shall suppress hydrodynamic instabilities and also provide sufficient

damping to limit shaft vibrations. Vibration sensors shall be provided for each bearing. Suitable provision shall be provided for each bearing so that wear on the bearings can be

readily ascertained. These equipments shall be finally fitted and stamped on site after the alignment of the rotors has been proved. The design and material specification of the bridge gauges shall prevent alterations in the gauge reading with variations in temperature.

1.3.10 Thrust Bearing The rotors shall be provided with a thrust bearing of the Mitchell or Kingsbury or equivalent

tilting multi-pad type which shall have identified main and reverse thrust faces sized to withstand all normal and abnormal thrust in either direction that can be experienced in service under the most adverse conditions. The thrust collar may be integral with the shaft or separate and replaceable. Integral collars shall be provided with a minimum of 3mm additional stock on each thrust face for remachining should the collar be damaged.

Vibration sensors shall be provided for the thrust bearing. Means shall be provided to indicate

excessive axial movement due to a failure of a thrust bearing, preferably combined with facilities to measure thrust movement on load. This is to be in accordance with manufacturer's standard design.

1.3.11 Temperature Supervision The Tenderer shall install duplex thermocouple in the white metal of each bearing of the gas

turbine and generator and also within each pad of the thrust bearing. This thermocouple shall be positioned to ensure a quick response in detecting abnormal changes in metal temperature. Any limitations on operating conditions, such as motoring the compressor and turbine generator, and the duration of transients shall be stated in the Bid.

Each of the above radial bearing and thrust bearings shall be provided with a resistance

temperature device to monitor oil drain temperatures which shall actuate both an alarm and trip on high oil temperature. Thermocouple will be acceptable in place of resistance temperature devices.

1.3.12 Glands





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Arrangements shall be made to preclude any leakage of gas blowing from the glands into the turbine enclosure or turbine hall. Renewable, metallic sealing rings shall be provided at all internal close clearance points between the rotor and stationary parts to minimize leakage of air, gas fuel combustion products and oil from the casings or housings.

1.3.13 Shaft Currents-Earthing Provision shall be made for the prevention of damage to bearings, oil pump drives etc., by

any shaft currents, which may be produced. Bearings and any associated pipes shall be insulated from ground and earthing brushes provided, and care shall be taken so that no extraneous earth paths, e.g through metallic cable sheaths, etc., shall short circuit the insulation.

1.3.14 Condensation and Corrosion The Tenderer shall state the precautions and necessary procedures to protect the

compressor and turbine components from corrosion and fouling when the plant is required to be off-service for long periods of standstill. Any necessary equipment such as heaters, hot air blower or other devices to maintain the plant especially the internal parts under warm and dry condition shall be provided.

1.3.15 Noise Limits The noise emanating from each gas turbine generator shall not exceed a limit of 85 dBA at a

distance of 1.0 m from the outline of the equipment. If the noise level requirements applicable to each gas turbine generator cannot be achieved,

then suitable acoustic hoods/enclosures or treatment shall be provided and installed with each gas turbine generator unit and its machine hall.

The use of earmuffs or earplugs are not considered as noise mitigative device. The Tenderer

shall however provide 50 sets of approved earmuffs. 1.3.16 Vibration, Balancing and Critical Speeds

Vibration monitoring equipment of the velocity type shall be provided for each main shaft bearing which shall indicate the severity of vibration expressed as an rms velocity in mm/s Vibration detectors should be mounted vertically or at an angle recommended by the manufacturer. Individual shafts, discs and couplings shall be dynamically balanced before assembly so that the severity of vibration of the complete unit during operation at any load is within the range of 2.8 to 7.1 mm/s rms velocity according to ISO Standards.

Any lateral or torsional critical speed of the total combined shaft system including the

generator and exciters (if any) should be at least 20% above or below the normal range of operating speeds However, if the critical speed(s) as calculated or revealed on test does not meet the specified separation margin, the response of the rotating assembly to the critical speed(s) in question shall be demonstrated and certified in accordance with API Standards.

Care shall be taken in the design of the stationary parts of the plant to ensure that no static

part is excited or touched/rubbed by vibration transmitted from the rotating parts. 1.3.17 Lube Oil System General





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A complete lube oil system, shall be provided for the turbine generator unit and shall be fully integrated with any associated relay oil, governing oil and dirty oil drains system supplied. The system shall have sufficient capacity to accommodate the requirements of the above systems with additional margin.

The specification of the lube oil shall be such that they can be procured from local sources. Lube oil shall be of the appropriate grade specific to heavy duty industrial type gas turbine

application. The Tenderer shall state in the Bid the equivalent type of lube oil from all leading brands.

The system shall include sufficient full standby equipment to allow any item of equipment

within the oil system to be taken out of service for maintenance without having to shut-down the unit and also without restricting in any way the normal full output operation of the gas turbine unit.

The capacity of the system and duty of the main oil pumps shall be such that the number of

complete changes of oil in the tank per hour does not exceed eight. Local and remote alarms shall indicate the operation of the a.c and d.c pumps or loss of oil

supply during the rundown period. Pressure accumulator shall be included in the oil system in order to avoid an unacceptable

pressure drop during starting of the standby oil pump, and also during the changeover of filters.

If positive displacement pumps are used, pressure relief valves shall be provided in for the full

supply quantity. The oil temperature rise through each bearing shall not exceed 30°C. The maximum bearing

oil drain temperature from each bearing shall not exceed 90°C and the maximum bearing metal temperature shall not exceed 115°C.

The oil system shall be designed to prevent the possibility of fire due to the leakage of vapors

or fluids from the systems onto high temperature parts as a result of physical damage or piping failure. As a minimum, this shall include the following.

a Double pipe or outer housings designed to retain leaking fluid and to resist physical

damage. b Suitable drains provided from the housings or double pipe to the lube oil tank. c. Lube oil pipings located away from cable trays. d. Oil piping routed around or below high temperature components where practical. Such

components to be additionally insulated and heat shielded. Lube Oil Pumps The pumps shall comply with the General Technical Requirements. Starting and stopping of

the motor driven pumps shall be normally automatic, but manual override facilities shall be incorporated.

Interlocks shall be provided to prevent starting of the gas turbine units in the absence of

adequate lube oil pressure. i. Main Lube Oil Pump The Main Lube Oil Pump shall be mechanically driven from the turbine shaft or A.C. motor

driven. The pump shall be of centrifugal type/ positive displacement gear type and shall be





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rated at 100% duty, sufficient to supply all oil requirements for the lubricating system as appropriate under all conditions of load.

Provision shall be made for automatic priming of the pump and for the maintenance of the

suction head. ii Auxiliary Lube Oil Pump The Auxiliary Oil Pump shall be A.C motor driven and preferably located integral with the

Lubricating Oil Tank. This pump shall be rated at 100% duty, as for the Main Lube Oil Pump and shall be self-priming. The pump shall be capable of allowing the turbine generator to operate under all conditions of load and speed with the Main Lube Oil Pump out of service and shall be available primarily for starting up of the turbine generator unit and for automatic standby upon rundown of the unit. The Auxiliary Lube Oil Pump stop and start initiation shall be accommodated by the provision of pressure switches to be supplied under this Contract.

The system shall be designed to ensure that the operation of the Auxiliary Lube Oil Pump

automatic start sequence does not allow the oil pressure to drop to a level that would trip the turbine generator unit.

iii. Emergency Lube Oil Pump One emergency rundown D.C driven pump shall be provided, preferably mounted integral

with the Lubricating Oil Tank, for supply of sufficient lubricating oil to the bearings when the unit is running down after a trip. The pump shall come into operation automatically on low oil pressure or loss of A.C supplies. The D.C emergency rundown oil pump shall be arranged to enable the turbine-generator to be brought to rest without damage under mishap conditions such as the total loss of A.C supplies.

iv. Hydraulic oil pumps (If required) 2x100% Hydraulic oil pump shall be of AC motor driven capable of supplying control oil

requirement. The constructional and operating features shall be same as that of Auxiliary lube oil pump described above.

v. Jacking Oil Pump 1x100% AC motor driven positive displacement pump shall be provided. Separate supplies to

each bearing shall be provided so that the rotors may be lifted in their bearings to reduce the torque load on the barring gear or if hand barring is operated.

Lubricating Oil Tank The lubricating oil storage tank associated with the gas turbine shall be of welded

construction of high quality carbon steel plate and its capacity shall provide adequate residence time under normal operating conditions. The tank shall be positioned so that there is adequate gravity drainage from the system to the tank and from the tank to the transfer/drains tank.

Suitable removable fine mesh strainers shall be provided at all inlets of the tank and

inspection of the strainers shall be possible with the machine running.





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The oil tank shall be vented by two 100% duty A.C motor driven vapor extractor fans . Each vapor extractor impeller and casing shall be made of materials that will not cause sparking should contact occur. The fan motor shall be of flame-proof type.

Vent shall be taken outside the building or enclosure preferable to above roof level and

directed away from the building and gas turbine air filtration plant. Any horizontal vent pipe shall have a natural drainage back to the tank and suitable drainage of oil build-up shall be provided at the discharge from the extractors and elsewhere in the vent system as necessary.

Vent shall be provided with demister to prevent oil spray into the atmosphere. The demister

shall be designed to limit lubricating oil emissions to minimum. Internally, the tank shall be baffled to ensure adequate deaeration of the oil. Apart from

baffles there should be no equipment located within the tank. Sufficient bolted covers shall be provided for access by maintenance personnel to each compartment for inspection and cleaning purposes. Access rungs shall be provided to permit safe and easy access. All loose and fixed covers on the top surface of the tank shall be located on raised rims of atleast 25 mm above tank surface and gasketed with locating pins.

In order to avoid welding at site, which could damage the tank internal painting, all necessary

pipe connections etc., shall consist of flange stub connections welded on the tank. In no case shall the tank be drilled and studs or bolts fitted from the inside of the tank.

The main oil suction point (the bottom of the bore of the connection) shall not be closer than

150 mm from the base of the tank. The tank shall be provided with a full complement of isolating and drain valves with a cap and

also, with a filling point fitted with a cover. There shall be convenient coupling connections with isolating valves for the portable oil purifier unit.

The base of the tank shall slope to a common point to facilitate complete draining of the tank

and an accessible lockable drain valve shall be provided and fitted directly against the tank for this purpose. Piping shall be provided from the drain valve to a suitable point where the oil can be run into the dirty oil storage tank or dirty drain tank.

Sampling points including the necessary fittings shall be provided at suitable locations on the

oil tank. Switches shall be provided for initiating low oil level alarms. The switches shall be of the type

which are completely sealed at the mounting point, such that leakage of oil through the switch is impossible. Two level switches shall be provided which shall be used to initiate alarms when the oil level is low and the lower one shall be used to initiate a trip of the turbine. A visual oil level gauge shall also be provided and shall be capable of being read local to the tank.

The tank shall be painted internally with a suitable oil, heat and corrosion resistant paint as

per the requirements of the painting specification. The tank shall also be painted externally. Oil Filters All oil filters shall be of the duplex type and shall be capable of change over during operation

without interruption. The changeover valves shall be interlocked or arranged so that it is not possible to inadvertently cut off the supply of oil to the unit. A differential pressure gauge along with Differential Pressure Switch shall be provided across each filter. Adequate provision shall be made for draining, venting and cleaning the section of filter housing undergoing maintenance. The drain and vent pipes shall be connected to the dirty oil drains system.





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Bypass relief valves shall not be fitted across filters. Each filter shall be designed to

withstand the maximum differential pressure that should occur in the oil system. Filters of 5 microns or smaller shall be provided for lube oil, whereas filters of 0.5 micron shall

be provided for the control oil systems. Lubricating oil pressure shall be sensed after the filter for the purpose of cutting in and out of

the standby and emergency pumps and for initiating a low oil pressure alarm at one level, followed by a trip initiation at a lower level.

The lubricating oil filters shall be positioned as close as possible to the feed points of the

machine. If the control oil is filtered separately from the main oil, duplicate 100% duty filters which will

allow on-load cleaning and change over from one filter to the other without interruption to full oil flow shall be provided.

Portable / fixed, lube oil purifiers shall be provided as per manufacturer's standards. Lubricating Oil Coolers Two 100 % duty oil coolers shall be provided for the Gas Turbine Generator unit. The design, size and change-over facility of the coolers shall be so arranged that cleaning of

any one of the cooler unit is possible during peak load operation of the gas turbine generator. The design shall be based upon tubular heat exchanger with closed circuit cooling water

passing through the tubes and the lubricating oil through the shell and over the tubes. The cooling medium (DM water) in the closed loop system will be in turn cooled by forced air in a radiator.

The materials of construction of the oil/water cooler tubes and the tube sheet shall be

admiralty brass. The tubes shall be straight and not of the hair-pin or coil type. The tube sheet shall have provision for differential expansion between the cooler shell and

the tube bundle. The cooler shells shall be constructed of appropriate grade steel and shall be fitted with an air vent at the highest point on the shell and a drain valve with cap..

The cooler waterboxes shall be fabricated from appropriate grade stainless steel, the highest

point of each waterbox supplied with a connection for priming and another fitted with an isolating valve for use with siphonic system vents. An expansion relief valve, and all appropriate drain and air release valves, shall be provided with pipework leading to the nearest station perimeter drain.

The cooler shall be supported such that the waterboxes can be removed without difficulty and

adequate access to the tube plates is possible. The arrangement of waterbox connections shall be such that tubes can be cleaned without

breaking any oil or water pipe joints and withdrawal of the tube bundle should be possible. Cooler top covers shall be fitted with adequate tube bundle withdrawal facilities and lifting lugs and jigs shall also be provided for lifting of the tube bundle into place.

The coolers shall be provided on the oil side with an automatic pressure relief bypass. It is preferred that the oil pressure in the coolers should be greater than the cooling water

pressure under all running conditions.





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A pressure monitoring arrangement shall be provided for each oil cooler to initiate an alarm in

the event of the water pressure exceeding the oil pressure. Onload testing of these alarm initiating devices shall be possible.

Closed Circuit Cooling Water System (CCCWS)

For each gas turbine generator unit, one closed circuit cooling system shall be provided complete and fully functional in itself.

Closed loop cooling system shall be provided with Air Fin Cooler with 25% margin on cooling

capacity & 2x100% cooling water pumps. Inhibitors, which are used in cooling water to reduce corrosion, must be free from poisonous

components like chromates. One Expansion tank alongwith level indicators, level switches, float valves, tank filling line will be

provided in each unit Air fin cooling system.

Closed cooling water will be Deminearalised water. Cooling water make up to the expansion tank shall be from plant DM water system.

Material of cooler pipes shall be selected in view of possible corrosion and is subject to approval

by the Engineer.

The design shall incorporate adequate equipment for taking water samples for testing to introduce inhibitors. Inhibitors shall be provided for initial fill & one month of operation after plant handover.

One tap-off valve for each cooler (which shall be used to fix a water hose for cleaning purpose -

to be connected to the plant service water supply system) shall be provided. Lube Oil Purifiers:

One common centrifugal oil purifier skid with1x100% centrifuge for all four(4) Gas Turbine units, for water and sludge removal from the lubricating oil shall be provided. It shall be AC motor driven and shall have an hourly capacity of not less than 25% of the total oil quantity in the lubricating systems of one unit. It shall be capable of being permanently connected to the lubricating oil system in such a manner that it can be operated when the turbine generators are either running or shut down. It shall be provided with all necessary pipe connections, including connections for drainage to the dirty oil drains system and for supply of the sealing water, if required, to be taken from the Plant Water System. Centrifuge shall have an automatic shut-off facility in case of power failure. Those parts of the purifier that are liable to corrosion, in particular the bowls, shall be manufactured from stainless steel. The purifier shall be provided with an indirect electrical heating system with thermostatic control arrangement to heat the incoming oil as necessary from the optimum purifier performance.





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It is preferred that this heating system should also provide for increased heating capacity to be utilised in conjunction with elevated oil temperature for oil flushing purposes, both during initial commissioning and subsequently after each unit overhaul / oil change. The purifier shall be provided with all necessary cleaning tools and equipment to effect maintenance cleaning.

Lube Oil Pipe work and Valves All pipe works shall be seamless stainless steel unless otherwise approved. All welded joints shall be subjected to 100% radiographic examination and shall have root

runs of weld carried out by the Gas Tungsten Arc Welding Method. Oil piping shall be pickled and during commissioning, oil flushing with alternate cold and heated oil shall be carried out.

The fasteners of the oil pipe must be such that vibration is substantially reduced and

particular attention shall be paid to the integrity of areas of high stress concentrations caused by expansion and contraction of the gas turbine generator unit. All pipebends shall preferably be of long radius. Ferrules used for joints in the control and relay oil system shall be of reliable make. Tenderer shall obtain Purchaser's approval for the make of the ferrules.

Temporary oil filters shall be provided for initial operation. Provision shall be made for the collection and detection of any leaking oil. Details of the oil

leakage guard system shall be given in the Bid. The drain pipework is to be designed such that it copes adequately with all oil flows to be

encountered without flooding. Sight flow inspection boxes shall be provided on all return oil pipes from each bearing and

shall be suitably located in a position with proper illumination for the personnel to inspect from a local platform or operating platform level. The boxes shall be fitted with toughened glass to withstand breakage. They shall be designed such that oil splash does not occur and that good vision within the box is maintained at all times. The boxes should preferably have a V-notch weir or other facility to show normal flow.

Protection against overpressure in a line shall be provided. Relief lines from the pump

discharge piping shall be directed back to the supply tank. Lube Oil Transfer The system will be used for replacement and refilling of oil from/to the common oil tank. The oil

from the common oil tank will be pumped by the pump of common oil purifier unit and discharged into an adequately sized inflatable container. After the unit oil tank is fully empty and cleaned, the pump of oil purifier unit shall be used to fill the oil tank with fresh oil by taking suction from tanker/inflatable container. All necessary piping valves, instruments & interconnection required to achieve the above philosophy of oil replacement/refill shall be supplied.

Oil Drains System A dirty oil drain collection tank and all associated pipework common to all four(4) Gas Turbine

Generators shall be provided for the turbine generator unit, to collect oil by gravity drainage from oil leakage, venting and draining points such as pump glands, control valves, oil strainers, drip trays, lubricating oil filter, vent ,drain tundishes and false start drains.





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The minimum capacity of the sump tank shall be 4 m3 plus 10 false starts for one Gas Turbine.. The dirty oil will be pumped from the dirty oil drains collection tank to off-site disposal by means of a pump or by vacuum trucking. The pump shall be of explosion proof submersible type. The pump and pipework shall be permanently installed.

The materials and procedure of construction of the tank and system shall comply fully with the

requirements of the General Technical Requirement. The drains tank shall be located within a Gas Turbine area.

1.3.18 Grease Lubrication System Grease lubrication for all appropriate sliding surfaces on the turbine generators shall be

supplied in accordance with the General Technical Requirements. Grease ways in sliding feed, soleplates, bearing blocks, etc., shall not be fed from a single

feed into a common internal chamber. Each greaseway shall be separately fed from the outside and shall go through to the other side of the item, where a grease nipple shall be fitted to allow back-purging or reverse direction greasing of the greaseway. In case of difficult access the back-purging connections shall also be permanently piped to conveniently located grease battery station. Screwed joints in grease piping shall be eliminated wherever practicable to avoid the possibility of grease leakage.

The Tenderer shall list all type of recommended grease used for the plant and also the

equivalent grease from all the leading grease manufacturer. 1.3.19 Turning Gear System/ Auxiliary Hydraulic Ratchet System This turning device shall rotate the gas turbine rotor after the gas turbine plant has been

switched-off, so long and with sufficient speed until the cooling of the rotor has progressed to the point that a remaining deformation at shut down is excluded.

The turning device must automatically come out of engagement as soon as the turbine speed exceeds the turning speed. The turning speed shall ensure a safe lubrication film formation. The turning device shall also ensure a complete safe shut-down of the turbine even during the condition of complete failure of A.C power.

Facilities shall also be provided for manually turning the gas turbine generators rotor during

maintenance outage. The manual facilities shall be based on portable hydraulic system. The period of barring before start up and after run down under hot and cold conditions and

also the turning speed(s) shall be stated in the Bid and the reasons given for such a period. Full details of the turning gear system shall be included in the Bid.

1.3.20 Starting System

Starting equipment shall be of robust design and construction, proven in service and be of such a rating that the torque available up to the self-sustaining speed of the gas turbine generator is in excess of requirements by a margin of at least 10%. Curves showing the relationship between starting torque required by the gas turbine and torque available against speed, together with speed against time shall be given in the Bid. The starting system shall be by Static Frequency Converter (SFC) or by a starting motor coupled to the rotor of the Gas turbine. The starting system should be rated without limitation on the number of starts attempted in succession and without restricting the rate of starting.





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If the system offered has limitations on the number of consecutive start attempts in a time period, this limitation with reasons shall be fully explained and justified in the Bid. The minimum starting times, under normal hot and cold start conditions from initiation of start sequence to synchronization and from synchronization to full load shall be stated in the Bid Interlocks shall be provided to prevent starting of the turbine generator unit in the absence of adequate lubricating oil pressure.

Details of the starting system shall be stated in the Bid together with statistics on reliability and availability.

1.3.21 Purging Each gas turbine shall have automatic purging system. The combustion chamber and

exhaust plenum shall be automatically purged with air prior to ignition and upon shutdown to remove traces of fuel that could cause explosions.

1.3.22 Shaft Drive Coupling and Alignment The coupling shall be designed for the worst anticipated condition of a short circuit reaction

from the generator or an attempted out-of-phase synchronization. Details of the design basis on which the couplings have been designed shall be stated in the Bid.

The tolerance on misalignment of the coupling and the load that can be transmitted in that

condition shall be stated in the Bid. 1.3.23 Bolt Tightening Equipment Two complete sets of equipment for tightening compressor casing, turbine casing and shaft

coupling bolts complete with accessories shall be provided. This equipment may be either hydraulic or electric heating element type.

The Tenderer shall state the time required for bolting and unbolting operations using the

equipment offered and the detailed description of the equipment proposed. The design and rating of the equipment shall be such that the bolting or unbolting times are reduced to a practicable minimum.

Provision shall be made for direct measurement of imposed tightening strain on high

temperature bolts, whether mechanically or thermally extended, by means of suitable bore holes and the use of depth gauges.

If hydraulic bolt stretching equipment is offered, the Tenderer shall briefly describe the

procedure for tightening the bolts. In this case all necessary items shall be provided including four full sets of spares for all wearing parts.

For tightening using heating elements it shall include all necessary apparatus, including

transformer together with six full sets of spares for the heating elements and insulators. 1.3.24 Air Intake System and Filtration General





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The primary function of the air intake system shall be to provide the gas turbine with sufficient

clean ambient air for combustion and for internal cooling of gas turbine blades. The intake system shall be complete with inlet screen, mist eliminator, filters, airtight duct

from filters to compressor inlet, outlet trash screen, sound attenuators and all controls and instrumentation necessary for safe control.

The number of access points and penetrations into the air inlet system for maintenance and

inspection shall be minimized. Any door or hatch shall be capable of being securely air-tight locked and interlocks and shall be provided to prevent any attempted start of GT with any door or hatch not properly closed.

Air Intake The air intake must be atleast 2.5 m above ground level to ensure that no ground dust is

drawn in. It shall be protected by a weather hood. Protection against sand/dust storm shall be provided. The air intake shall also be positioned to avoid the ingress of exhaust gases from the gas turbine bypass stacks. The design of the hood shall not hinder access by men or crane facilities to the air filtration plant.

The intake silencing system should be designed such that total noise at a distance of 122

meters from the Gas Turbines is limited to 50 dBA. In addition the sound level in each of the Octave bands must not exceed the NC-40 criteria.

In order to keep the plan dimension within a reasonable limit, a multitier filter house will have to be implemented.

Air Filtration Plant The filter cleaning system shall be of self cleaning type with sequence timers. Air velocity through the filter media must be as per the standard requirement. The pressure

design of the complete air inlet system shall be based on the maximum possible pressure rise occurring during surging of the compressor.

The overall efficiency of the filters shall not fall below 99.5% after extended service of not less

than 24,000 equivalent fired hours, such that particles remaining in the filtered air shall not exceed 5 microns diameter.

The air intake shall be equipped with a silencer downstream of the filtration system. The

design of the silencers shall be of a standard arrangement with baffles and acoustic insulation lining of the ducts. The sound insulation covering shall consist of stainless steel sheet.

Access ladders with safety hoops, platforms and stairways shall be provided so that all the

stages of the filter units can be easily inspected, cleaned or replaced. The filter housing shall contain drainage points which shall be piped to the station drainage

system, including all pipes, valves and fittings. General service air and water outlet including all necessary pipeworks, isolation valves, quick

connecting hose couplings, flexible hoses and nozzles, supporting steelwork, and other equipments required to complete the system shall be provided at a suitable position for the





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purpose of cleaning and routine maintenance of the plant. Pipe to hose couplings must be installed at the pipes for connection of the flexible hoses. All hoses and nozzles to be provided for the cleaning procedure shall be stored in a suitable corrosion resistant metal cabinet with padlock near the air filtration plant. Flexible hose shall be rated to atleast 15 bar and the length for each of the air and water hoses required shall cover the whole area of the air filtration plant.

Adequate interior lighting to the air filtration plant shall be provided for operation and

maintenance. The design data on which the filtration system is based shall be stated in the Bid. The details

shall give the anticipated particle size distribution upstream and down stream of the filter unit and include curves of separation efficiency.

The proposed filter plant shall be fully described in the Bid, together with anticipated time

interval between renewal of the filter elements, the cost of the elements and the time taken to install all the filter elements of the filtration plant.

The design shall minimize the inlet system pressure drop. The instrumentation and control

equipment shall also be kept to a minimum but must include differential pressure gauge to measure pressure drop across each filter stages and the overall differential pressure of the filtration system. The differential pressure gauge and accessories shall be of weather-proof type and made of appropriate corrosion resistance material.

The local differential pressure gauge for overall pressure drop and for each filter stages shall

be located not more than 1.5 m above ground level and covered with corrosion resistance metal cabinet complete with local lighting.

The overall differential pressure gauge will initiate an alarm for high pressure drop at a preset

value and to automatically protect the air compressor should the pressure drop reach the maximum allowable limit.

Air Inlet Ducting The ducting shall be complete with all the necessary expansion joints, guide vanes supports

and supporting steelwork, vibration isolators, flanges, silencing equipment, outlet trash screen, insulation and cladding and any other items necessary to complete the system.

Ducting expansion shall be accommodated by means of proven expansion joints such that no

loads or forces are transmitted to the air compressor inlet flange. Sliding joints shall not be used in the ductwork. All expansion joints shall be flanged for

removal without disturbing the main sections of the ducting. The ductwork shall be of appropriate corrosion and wear-resistant grade steel, not less than

5 mm thick. The material of the duct guide vanes, expansion joints, outlet trash screen and other parts shall be suitable for the full load flow and temperature conditions.

All ductwork surfaces shall be shot blasted to remove mill scale before and after assembly.

No entrapped nuts, bolts or rivets shall be used inside the ductwork downstream of the filter. Air tight access doors of proven type shall be provided to give access to ducts for inspection

and maintenance at the location before and after the silencer. They shall be of the flange type and not less than 1m x 1m size. The ducts shall be adequately stiffened to support the doors. Any door or hatch shall be capable of being securely locked and interlocks shall be provided to prevent any attempted start with the doors open.





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Attention shall be paid to the provision of landing platforms local to any access doors for the air ducting. To ensure safety and convenience of access, landing platforms shall be provided inside and outside the ducts where there is no obvious landing within 1 meter of the door itself. Such platforms are to be bolted or resting type for ease of removal. The platform shall be provided complete with a safety rail and access ladder with safety hoops.

The ductwork shall be sloped 1 in 7 and contain drainage points which shall be piped to the

station drainage system, including all pipes, valves and fittings. The silencer shall be capable of being removed from the ductwork without dismantling or

removing any other ductwork other than that portion containing the silencer. The infill and panels shall be fully resistant to the worst atmospheric conditions anticipated on site. Precautions shall be taken to prevent settling or packing of the infill material and also the small components or parts of the silencer cannot become detached and obstruct air passages. The infill material shall be vermin proof. The materials of construction of the intake silencer and ducting shall be stated in the Bid.

A series of test ports shall be arranged in the ducts at suitable positions according to

performance guarantee test standard such that the distribution and temperature of the air can be determined and the filtered air sampled. The test points shall be fitted with covers so arranged that their removal does not entail damage to the insulation if any. The covers shall be completely gas tight and retained against loss by chaining or other approved means.

Filtered air sampling instrument including all necessary accessories shall be provided. All necessary access ladders with safety hoops, platforms and guard rails shall be provided to

allow easy and safe access to the test ports. Air Processing Unit A skid mounted Air Processing Unit (APU) shall be provided to supply dry air required for

pulse cleaning of the inlet air filter elements for each Gt. The unit shall be complete with finned tube cooler (for cooling the air tapped from the compressor) self-regulating pressure control valve, pre-filter, desiccant filled columns, after filters, interconnecting pipework, instrumentation and controls. One column shall supply the required quantity of dry air with the other column being regenerated. Bidder shall indicate the method of regeneration proposed to be employed.

1.3.25 Gas Turbine Exhaust System

The GT exhaust system shall include the exhaust ducting, expansion joints, vibration isolations, supporting steelwork and flanges, inspection doors, silencing equipment, insulation, cladding, and any other plant and equipment required to complete the system.

Exhaust Ducting

The Exhaust duct shall be complete with an insulated, gas-tight steel casing, which shall be reinforced with structural steel stiffeners. Material shall be carbon steel, with inner surface insulated with preformed mattresses and stainless steel inner liner.

Casings shall be gas tight to prevent insulation failure. They shall be complete with access

doors as necessary.

The gas turbine shall be provided with an independent exhaust ducting system to direct the exhaust gas to the stack. The whole of the exhaust system shall be designed to withstand a back pressure of not less than 50 mbar(g).





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Pressure drop in gas path through the silencer should not exceed 40 mm water gauge.

All ducting shall be designed to reduce the accumulation of deposits to a minimum. To ensure distribution of exhaust gas deflector shall be provided.

An expansion joints shall be installed to accommodate duct expansion and prevent undue

thermal stresses in the ductwork under all operating conditions.

A minimum of 8 test points shall be arranged in the ducts at approved positions such that the distribution and temperature of the exhaust gas can be determined and the exhaust gas sampled. The test points shall be fitted with covers so arranged that their removal does not entail damage to the insulation. The covers shall be completely gas tight and secured against loss by chaining or other means approved by the Engineer.

Instrument points shall be provided in the ducts for monitoring, testing and checking purposes.

Gas tight access doors of an approved standard type shall be provided to give access to ducts for inspection and maintenance. They shall be of the flanged type and not less than 600 mm x 600 mm size.

The ducts shall be adequately stiffened to support the doors.

Attention shall be paid to the provision of landing platforms local to any access doors to ensure safety and convenience of access.

The design of the exhaust system shall be such that under all operating modes site conditions there must be no condensation within the system. Preformed lagging shall be secured to the ductwork and clad with suitable sheeting to reduce the heat radiation to a minimum and to protect against the entry of rain water.

The ducting shall be designed so that rain water falling on the cladding shall run off.

The exhaust duct system shall be designed to avoid vibration and any resonance with the exhaust gas pulsations under all operating conditions.

The gas velocity at ISO-base load operating condition shall not exceed the following values :

- within Stack 48 m/s

The ducts shall be of all welded steel plate construction suitably stiffened where necessary by means of angles, tees or flats secured to the outside of the ducts.

The duct wall and roof shall not be less than 6 mm thick. The duct floor shall be adequately supported and not less than 8 mm thick (including a corrosion allowance of 3 mm).

The welding of ducts shall be continuous internally but externally may be discontinuous. Sections of the ducts shall be bolted together and the joints shall be sealed by welding after erection at Site. All parts of exhaust ducting, stack, exhaust silencer shall be above the grade level i.e. none of the exhaust system shall be in trench or below the grade level.

All joints between sections of ducts shall be made by means of angles of approved size welded to the plating. Joint bolts shall not be less than 15 mm diameter with a pitch of not more than 100 mm. All bolted joints shall be made with sealing tape approximately 3 mm thick over the full width of the flange or with an approved type of jointing material.





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The ductwork shall contain drainage points of adequate size of rain removal which shall be

piped to the station drain system.

All ductwork surfaces shall be shot-blasted to remove all mill scale before site assembly.

The material of the ductwork, guide vanes, expansion joints and all other parts of the exhaust system shall be suitable in every respect for thermal cycling and continuous operation at the high temperature conditions pertaining to the maximum load on the gas turbine at the highest ambient temperature. Stress levels shall be kept to levels which ensure a creep life at the maximum temperature of at least 100,000 hours.

Sliding joints shall not be used in the ductwork.

The expansion joints shall be able to withstand the maximum possible longitudinal and angular

misalignments, which shall be stated in the Bid.

Detailed description and calculations of the allowance for thermal expansion shall be submitted.

The expansion joints shall be provided with internal plates to prevent eddies or the deposition of dust in the joints.

All expansion joints shall be flanged for removal without disturbing the main sections of the ducting.

The Lagging shall be sectionalised for removal local to the expansion joints. Bolts for the flanged joints shall not be less than 15 mm diameter.

The internal insulation shall be covered with stainless steel lining. The external insulation and cladding shall be of same type as specified for the duct. For ease of maintenance staircase(s), walkway(s), platform(s), inspection doors and hoist(s) with sufficient working range and lifting capacity shall be provided.

Exhaust Silencer

A silencer of stainless steel construction shall be provided in the gas turbine ducting between GT outlet to stack to reduce the plant noise levels in accordance with the General technical specification Vol-II

The silencer acoustic panels shall be designed for the operating life of the plant, at continuous operation with base load mass flow and maximum gas temperature. The silencer shall be removable from the ductwork without dismantling or removing any other ductwork except that containing the silencer Velocity through the silencer must not exceed 45 m/sec. Exhaust gas silencer section must be designed such that the exhaust gas velocity does not exceed 48 m/sec. In addition the pressure drop in gas path through silencer should not exceed 40 mm water gauge.

The infill and panels shall be fully resistant to the exhaust gas temperature.

The Bidder shall submit in his Bid full details of the silencing equipment offered and supported by silencer performance curves.

Exhaust Stack





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The stack shall be self-supporting and shall terminate at sufficient height atleast 30 M above ground level to ensure that the ground pollutants are within the limits specified. The stack bottom shall be designed suitable for drainage. The height of the stack shall also take into account the height and disposition of the surrounding buildings and the location of the air intake systems. The stack shall be designed and constructed to AISC or equivalent approved standard and in all respects to the approval of the Purchaser. The stack shall be cladded and thermally insulated to protect personnel and improve appearance.

The stack shall be fitted with a drain and access manhole at its base. At the top a platform shall

be provided around the full circumference and an access ladder with safety hook. The design of the stack shall be such that under all operating modes and site conditions there must be no condensation within the stack.

The stack shall be equipped with suitable earthing bosses.

The exhaust stack shall withstand all wind loads as specified. The stack shall be provided with

access ladder to the top where a circular platform with lightening rods and warning lights shall be installed.

The exhaust ducts and stack shall be internal heat insulated and equipped inside with stainless steel lining. Exhaust gas velocity should not exceed 48 m/sec.

If the Contractor has not provided a similar exhaust system including diffuser, silencer and stack, he shall perform a model test in presence of the engineer prior to presenting relevant drawings for approval.

The stack shall be provided with NOX, SOX, CO measuring facility. The location of the gas sampling shall be as per EPA regulation. Stack ladder shall be provided with safety cage.

Steelwork

The Bidder shall supply all necessary structural steel work for the support, bracing and re-

inforcement of the exhaust gas ducting, exhaust stacks and miscellaneous equipment. Fabrication & Erection of structural steel work shall be as per civil & structural specifications.

The steelwork shall be provided in accordance with the general requirements for steelwork given elsewhere in the Bid Documents.

Steel work shall be provided for piping supports and instrument mountings.

Structural steel shall be supplied in pre-fabricated form to minimise site erection work.

The design of the steel structures associated with the stack & duct shall meet the following requirements:

The supporting structure shall be designed considering the internal forces and expansions, as well as considering the forces from wind, earthquake and sun/shade.

All nuts, bolts and washers must be galvanized or cadmium-plated, and properly protected against corrosion before installation.

The stack shall be provided with adequate numbers of intermediate platforms to facilitate the painting of the stack over the plant life of 30 years.





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Platforms and Stairs

All necessary platforms and stairs shall be provided to give adequate and safe access to the

Ducting & Stack for operation and maintenance purposes.

Access platform shall be provided to all operating, inspection and observation stations including test connection points and valve stations. Access platforms shall utilise galvanised steel grating for flooring and shall be complete with all necessary handrails and supports. Platforms and stairs of adequate width shall be provided.

Structural components shall have sufficient clearance to provide for operation and routine

maintenance and can be exposed during total overhauling. Grating clearance shall be 150mm maximum under operating conditions.

Platform perimeters, stairways and openings greater than 150mm in width shall be protected with handrailing. Handrailing throughout the plant shall be constructed from proprietary tubular fittings. Handrails constructed from angle or steel extrusions shall not be permitted. A minimum of 2,300mm head clearance shall be maintained for all walkways. Continuous kick plates projecting 100mm above the platform elevation shall be provided around all openings and all platform edges. When grating is cantilevered, the kickplate shall be attached to the supporting steelwork.

All operating valves and all instruments.

Vertical ladders more than 2.5m in length shall be provided with a safety cage.

1.3.26 Painting and Surface Preparation

All painting and surface preparation of the GT shall be in accordance with the general requirements laid down in the Specification for Painting. Prior to painting all exposed surfaces of the GT shall be free of oil, grease; dirt, millscale, rust corrosion products, oxides, paint or foreign matter.

Painting shades will be approved by the Purchaser. 1.3.27 Fire Detection and Protection system General The entire gas turbine generator installation including all auxiliary enclosures, shall be

protected from fire with a complete automatic fire protection system. The system shall be complete in all respects and shall include cylinders, cylinder racks, piping, valves nozzles, detectors, fire alarm actuating system and all other equipment necessary for the safe and efficient operation of the units.

The extinguishing agent shall be Carbon Dioxide (CO2). The fire protection system, suitable for units which will normally be unattended, shall be fully

automatic and shall be designed and installed in accordance with NFPA codes. . The fire detection and protection system shall be subject to the review of the authority having jurisdiction and to the approval of the Purchaser.





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All devices shall be located, installed and suitably protected against mechanical, chemical or other damage which may render them inoperative. All devices for shutting down supplementary equipment shall be considered integral parts of the system and shall function with system operation.

The system shall be designed for total flooding for closed-up enclosures and local application

for hazards in open spaces. The installation shall be interlocked with the GTG Enclosure ventilation system to prevent unnecessary extraction or circulation of extinguishing agent from the protected enclosure.

The Tenderer shall submit complete descriptive information of the fire protection and

detection equipment and gas fuel detection equipment to be supplied. Design Requirements The quantity of extinguishing agent shall be sufficient to ensure rapid extinction of any fire

and have adequate spare capacity. The extinguishing agent used for initial supply and replenishment shall be good commercial grade, free from contaminants that might cause container corrosion or interfere with the free discharge through the nozzle orifice.

2 x 100% fully filled cylinders along with all manifolds, piping, valves etc., of the fire

extinguishing agent shall be supplied for each enclosure / compartment to be covered. A minimum of two (2) gas masks with suitable activated filters shall be provided at the main

entrance to each protected enclosure. They shall be kept in a glass-fronted cabinet. A fuel leak addressable detection, measurement and indicating instrument alarm system

shall be furnished to monitor and initiate alarms of any hazardous levels of flammable gases within the gas turbine enclosure. Each section of the enclosure shall be provided with detector head. The control module shall monitor and alarm each detector head. Failure of the detection elements or their associated wiring shall be detected and displayed by a fault detection system.

Agent Containers The extinguishing agent containers supplied shall be of a type for which facilities are available

for refilling by local suppliers. Each cylinder shall be supported in an upright position by a steel cylinder support frame

suitable for wall and floor mounting. The frame shall include facilities for convenient individual servicing or content weighing.

A reliable means of indication other than weighing shall be provided to determine the

pressure in refillable containers. The means of indication shall account for variation of container pressure with temperature.

Each bank of cylinders shall be connected to a common header. Automatic means shall be

provided to prevent the loss of gas from the manifold if the system is operated when any cylinder is removed for maintenance.

Each cylinder shall be fitted with a level valve and pressure gauge. The valve shall

incorporate a safety outlet which is designed to burst and release the gas should the pressure





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in the cylinder rise to a dangerous level. The pressure gauge shall be marked in colour to indicate undercharging of the cylinder.

All cylinders supplying the same manifold outlet shall be interchangeable and of one selected

size and charge. Each system shall have a permanent nameplate specifying the number, filling weight and the

pressurization level of the containers. System Operation The systems shall operate from a voltage of 230VA.C (Any other voltage levels required shall

be derived by the bidder), 50Hz supplied to the power charger module within the control panel. This voltage is transformed and rectified within the panel. A nickel-cadmium standby battery shall be provided to cater to AC mains voltage failure condition. This battery will be automatically and instantaneously brought into use when the mains supply fails. Such a failure shall be indicated both visually and audibly at the panel. The battery shall be trickle charged during normal operation conditions.

A separate detector system and alarm shall be provided for each enclosure. A minimum of

two detectors shall be located in each area particularly susceptible to fire and/or areas which would sustain catastrophic fire damage. The bidder shall state which authorities have approved the fire detectors.

In order to discharge the extinguishing agent automatically, at least two detectors must be

activated. This mode of operation obviates the possibility of erroneous discharge due to one detector responding to conditions which are regarded as normal.

The detector's circuit wiring shall be supervised continuously for line fault. A disconnection

to this circuit would be indicated as a fault at the control panel both visually and audibly by a fault lamp and buzzer respectively. Remote indication of alarm and fault conditions shall be provided at the Master Alarm and Indicator Desk.

Provision shall be made to trip the gas turbine simultaneously with release of extinguishing

agent. Each compartment or enclosure shall be protected as a separate risk and the discharge of

the extinguishing agent into one compartment or enclosure shall not affect the other compartments or enclosures.

Automatic Detectors Detection shall be by a detector of a type appropriate to the hazard zone to be covered. The automatic detectors shall be of the Rate of rise heat detector. Additionally, the turbine

compartment and other compartment/chambers where Fuel gas is handled or present, flammable gas detector shall also be provided. The detectors shall be UL/FM approved.

Manual Actuation An independent facility for emergency operation, to manually discharge the extinguishing

agent via a "break glass" handle type manual switch/pull box shall be provided. This shall be mounted outside the exit door of the protected space.

The audible alarm and time delay relay can be actuated and smashing of the "break-glass"

shall cause the release of the extinguishing agent gas.





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All manual operating devices shall identify clearly the hazard being covered. Time Delay Relay A time delay relay set by manual switch shall be included to allow a time delay between

detection and the release of gas. This will enable the personnel to evacuate from the hazard area. The delay period shall be set to suit individual locations and sealed when the cylinders are installed. A mechanical lock-off device shall be provided to isolate the time delay relay when no personnel is working within a protected area.

Alarm Alarm bells shall be of the 150mm diameter pressed steel type with stove enamelled finished

in red and generate at least 90 dB above the surrounding's noise level. The word 'Fire' shall be printed on the bell in a contrasting colour and the letters shall not be less than 25 mm high.

The bell shall be of the trembling type, not single stroke and shall operate from the fire battery

supply. The failure of the bell circuit shall not interface with the transmission of an alarm. The bells shall be fully weatherproof and can be installed in any location for any alarm purpose.

Sufficient flashing light signs shall also be provided within the protected enclosures to warn

personnel to evacuate due to the imminent discharge of gas. Conspicuous warning and instruction notices in English and local shall be supplied and

installed for the fire protection system. Control Panel A control panel shall be suitably located near the gas turbine and shall consist of the following

items. i. Audible fault alarm, isolating switch, isolation indicator and alarm reset switch. ii Test switch for detector system without activation of gas discharge incorporating facilities

for testing and maintenance in accordance with the international standards and local requirements..

iii. Battery charging and test facilities, with volt and ammeter battery test switch. iv. 'Mains On', 'DC On', 'Battery Charger on', 'Mains Fail', 'DC Fail', 'Charger Fail', 'Battery

Low', 'Extinguishing Agent Discharged', 'Bell Fail', 'Common Fault' indicators. v. Time delay relay isolating switch. vi. Key switch for shutdown of actuating device. vii. Dry cell nickel-cadmium battery. viii. Exhaust fan cut-off relays. ix. Mimic diagram for the area covered by the fire detection and protection system including

the indicators showing the location and operation status of the detectors. x. Contacts for remote alarm and indication.





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The alarms and indicators shall be used to indicate the operations of the system, hazards to personnel, or failure of any supervised device. A positive alarm and indicator shall be provided to show that the system has operated.

An alarm shall be provided to give warning of discharge or imminent discharge where a

hazard to personnel may exist. Alarms indicating failure of supervised devices or equipment shall give prompt and positive

indication of any failure and shall be distinctive from alarms indicating operation or hazardous conditions.

Individual fire alarm annunciator equipment for each compartment or enclosure shall be

provided. The enclosure ventilating fans shall be stopped and openings closed automatically by

dampers in any enclosure in which the fire protection system comes into operation. Discharge Nozzle Discharge nozzles shall be listed for the use intended and for discharge characteristics. The

discharge nozzle shall consist of the orifice and any associated horn, shield or baffle. They shall be of adequate strength for use with the expected working pressures, be able to resist normal mechanical damage and withstand expected temperatures without deformation. Discharge orifices shall be of corrosion resistant metal.

Discharge nozzles shall be permanently marked to identify the nozzle and to show the

equivalent single orifice diameter regardless of shape and number of orifice. This equivalent diameter shall refer to the orifice diameter of the 'Standard' single orifice type nozzle having the same flow rates as the nozzle in question. The marking shall readily be discernible after connection.

Discharge nozzles shall be provided with frangible discs or blow-out caps where clogging by

foreign materials is likely. These devices shall provide an unobstructed opening upon system operation.

Remote Manual Control The remote manual control shall be a manual pull box which shall be of the 'Break glass' type The electrical release device shall consist of a microswitch set for a 30 seconds delay. On

activation of both detectors, the electrical release device which has a 30 seconds delay microswitch will in turn trigger off the release mechanism of the cylinder causing it to discharge the extinguishing agent.

Pipework and Fittings Pipework, pipe fitting, flexible piping, tubing or hoses (including connections) where used

shall be of approved material and pressure ratings. Piping shall be installed in accordance with good engineering practice. All piping shall be

routed to reduce friction losses to a reasonable minimum and care shall be taken to avoid restrictions due to foreign matter of faulty fabrication. The pipework shall have a gradual fall back towards the cylinders. A drain cock shall be provided at the lowest point of the pipework.





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Pipes shall be reamed and cleaned before assembly and after assembly, the entire piping system shall be blown out before nozzles or discharge devices are installed. Where valve arrangements introduce sections of closed piping, either pressure relief devices or valves designed to avoid entrapment of liquid gas shall be installed.

All valves shall be suitable for their intended use, particularly with regard to flow capacity,

operation, temperatures and other relevant conditions. Valves shall be protected against mechanical, chemical or other damage.

Flexible connections shall be provided at the outlet of the manifold header and be a heavy

duty braided type to be of the same size as the discharge pipe. One end of the connection shall be a union coupling for dismantling purposes.

Fire protection piping, cabling and components shall be located in such a manner as to not

impede the dismantling or removal of the unit housings. 1.3.28 Machinery Equipment Unit Enclosures Except as otherwise specified, all equipment shall be enclosed in a minimum number of

prefabricated enclosures. The enclosures shall be constructed in a neat and workmanlike manner.

Where fitted, the enclosures shall be of pleasing appearance, suitably stiffened and secured

to avoid thermal distortion. They shall be resistant to corrosion and mechanical damage. For the purpose of reducing maintenance outage periods to a practicable minimum, the

enclosures shall be designed to be readily removable. The enclosures shall be strengthened to facilitate removal and replacement without damage and arranged so that when enclosures are removed, instruments, instruments panels, gaugeboards and connections need not be disturbed.

Enclosures shall be designed for outdoor installation to absorb and limit noise emitted by the

gas turbine generator units. Enclosures shall be constructed of reinforced sheet metal lagging. Paintings shall be in accordance with Painting Specification as specified for structural steel and miscellaneous metals.

Enclosures shall be designed to permit easy accessibility to the equipment and to provide

necessary protection for maintenance personnel. Enclosures shall be provided with pedestrian and equipment doors of lockable type.

Enclosure insulation and ventilation shall be provided to maintain temperatures suitable for

personnel and for all systems whether on standby or operating. Enclosures shall be ventilated using motor driven fans mounted on top of the enclosure . Each enclosure shall be provided with 2 x 100% capacity fans.

Special care shall be taken to vent out any hazardous vapours which may accumulate inside

compartments. All vents shall be ducted & discharged at a safe height. Adequate explosion proof interior lighting shall be provided for operation and simple

maintenance. Emergency DC lighting shall be provided and shall be energized by an emergency changeover contactor. Emergency lighting power supply shall be supplied.





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Enclosure lighting shall be provided to maintain minimum illuminance level as follows. Emergency access areas - 150 lux All other areas - 50 lux Two general service air points shall be provided at a suitable position for each enclosures

including all necessary pipeworks, isolation valves, quick connecting hose couplings, supporting steelwork and other equipment required to complete the system for the purpose of cleaning and routine maintenance of the equipment.

The Tenderer shall provide portable vent blower cum extraction fan operating on 230 volts a.c

power supply complete with flexible duct and with power cable with matching power plug with the power socket installed at the unit enclosure.

The layout of equipment shall recognize human needs and limitations and ease of movement

during maintenance. If the area beneath the inlet air filter ducting extending to the ground level is utilized for

locating auxiliary equipment requiring an indoor environment, then this area shall be enclosed.

1.3.29 Fuel Systems The gas turbine shall be designed for both liquid and gaseous fuels.

Natural gas shall be used as primary fuel and Distillate Oil as a backup fuel. However the gas turbine shall also be suitable to fire Distillate Oil continuously up to base load operation. It shall be also possible to change over automatically in case of gas fuel supply failure to liquid fuel operation with out any reduction or limitation in the load, the turbine was delivering before such change over. The limitation if any for such duel fuel operation shall be clearly stated in the bid. The Bidder shall indicate in his tender the maximum acceptable levels of impurities of the fuel. The fuel systems shall be suitable for long continuous unattended operations and capable of being controlled automatically. The Contractor shall install all necessary fuel conditioning skids as applicable to remove constituents such as Sodium, Potassium, and vanadium or any condensate/ solid particulate matter so that they are within acceptable limits of the Gas Turbine. The liquid fuel system shall as a minimum consist of two nos. 100% capacity AC motor driven fuel oil pressurizing pumps, circular flow divider, fuel flow control valve, fuel stop valve, fine filter upstream of each pump, fuel oil manifold, non-return valves for combustion chambers, interconnected tubing, etc. The liquid fuel pressurizing pump shall be twin screw, non-contact type position displacement pump with timing gears. The pumps shall be provided with mechanical seals. The lubricating system of the pump shall ensure no leakage of Distillate Oil into the lube oil. The NPSH required for the pump shall be provided by the off-base Fuel Forwarding System. Bidder shall furnish complete details of the proposed pressurizing pump. To ensure uniform distribution of liquid fuel of all the combustion chambers, suitable flow divider shall be provided. Bidder shall furnish complete details of the proposed flow divider. The liquid fuel module consisting of the pressurizing pumps, flow divider, control & stop valves and the fine filter shall be located in a separate accessory compartment.





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An automatic minimum flow control feature shall be incorporated in the fuel system to enable continuous operation of the turbine at any desired load in the fuel mix mode. The minimum flow of liquid shall be adequate to prevent overheating of the fuel oil pressurizing pump casing because of the recycled by-pass flow. If necessary, the recycled piping shall be extended back to the liquid fuel tank in order to reduce the minimum flow required. Bidder shall furnish a write-up on the proposed minimum flow control procedure. All piping and tubing in the liquid fuel stream down stream of the off-base fine filter skid shall be in stainless steel construction. Similarly, on-base fuel gas piping which shall be down-stream of the gas conditioning skid shall be in stainless steel construction. Provisions shall be made in the design to allow purging and flushing of any item of equipment and associated piping that can be taken out of service for maintenance without the need for turbine shutdown. Full details of the gas turbine fuel system shall be given in the Bid. The Bidder shall include all local gauges and instruments necessary for the manual and local supervision, test and commissioning of the fuel system. All supports and straps, hangers, anchors etc. necessary for the pipe runs are to be included.

For the requirement of the Fuel Handling System, Section 4.0 & Section 5.0 of Vol. III shall be referred.

1.3.30 Emission Control

The oxides of nitrogen (NOx ) emissions in the exhaust gas from the gas turbine operating base load on natural gas shall not exceed the pollution control specified values. No water injection scheme has been envisaged in this specification due to water scarcity.

1.3.31 Gas Turbine Control, Instrumentation and Governing Philosophy The requirement is for a consistent control and instrumentation philosophy to apply

throughout the plant and implemented by a range of control and instrumentation hardware exhibiting the minimum diversity of supply and manufacture. All control and instrumentation systems offered for the control and the supervision of the plant specified shall be subject to the requirement of Specification.

1.4.0 MAINTENANCE/INSPECTION REQUIREMENTS OF GTG & AUXILIARIES Please refer to the Clause No. 6.1 of General Technical Specification wherein it is stated that

the plant is to be designed for 30 years life. Tenderer to clearly state in his bid, which are the parts which need maintenance/replacement periodically. Tenderer to furnish such a list along with replacement period. Also Tenderer to indicate a regular inspection schedule (ie.) inspection required for every “X” running hours throughout the life of the plant.

1.5.0 DOCUMENT/DRAWINGS TO BE SUBMITTED ALONG WITH THE BID Following is the list of attachments to be submitted with the bid as indicated in various pages

in the tender specification for the GTG and auxiliaries.. Tenderer to put a check list for having enclosed the documents. and submit along with the GTG portion of the offer.





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Also Tenderer to submit various, drawings, technical informations, correction curves etc., as given in Volume II - General Technical Specification.

SL. NO.

DOCUMENTS WHETHER PROVIDED

1 Details of control provided for Compressor surge/exhaust

temperature control Yes/No

2 Normal and maximum limits of temperature scatter (spread)

at the turbine inlet and its control Yes/No

3 Facility for inspection Yes/No 4 Ventilation system for Gas Turbine/Combustion chamber,

enclosure. Yes/No

5 Write up on stationary & moving blades rotor welding

procedures Yes/No

6 Stationary & moving blade materials Yes/No 7 Lubricating & cooling system Yes/No 8 Type of recommended grease & equivalent for the same Yes/No 9 Details of turning gear system Yes/No 10 Curves showing the relation between starting torque

required by the gas turbine and torque available against speed together with speed against time

Yes/No

11 Write up on starting system Yes/No 12 Design data of Intake Air filtration system and write up on

filtration system, Air processing unit Yes/No

13 Descriptive information of fire protection and detection

equipment and gas fuel detection equipment Yes/No

14 Details of Gas Turbine fuel system. Yes/No 15 Maintenance/Replacement schedule of parts of GTG Yes/No 16 Detailed P&IDs of Gas Turbine auxiliaries Yes/No 17 Inspection schedule Yes/No





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1.6.0 SPECIFIED DESIGN DATA

Minimum Requirements Description Unit Data

Mechanical Gas Turbine & Auxiliaries General Numbers required No. 4(Four) Type & Model No. Bidder to specify Location Outdoor with weather proof and

noise attenuation enclosure or indoor

Thermodynamic cycle Joule Brayton

Compressor Type Axial flow, heavy duty Casing type Split Inlet pressure of air bar As given in 'General Technical

Specification' Inlet temp of air °C As given in 'General Technical

Specification' Bleeding of air for turbine blade cooling Required Variable inlet guide vanes Required

Bleeding of air for purging intake air filters Required Surge control Required

(Bidder to indicate method)

Compressor washing/cleaning arrangements Required. Protective coating on discs and blades in hot end of compressor

Required

Combustion Chamber Type Low NOx type to meet emission

levels indicated in this specification





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Igniter type/ Numbers HEA type / As per manufacturers standard

Flame detector Nos. and type Nos. 2 nos. (min.) ultra violet Gas Turbine Application To drive electric generator Duty Heavy duty base load Capability of continuous operation and start/stop operation of the gas turbine

Required

Critical speed of rotor Must not be within the range of

± 20% of rated speed (RPM)

Design maximum speed of rotor Greater than 1.20 times the rated speed

Noise level Less than 85 dBA at 1.0 m from

the outline/enclosure of the equipment

Vibration (in any direction at the journals under all loads) 2.8 to 7.1 mm/s rms velocity as

per ISO 10816. Weather proof enclosure Required Acoustic enclosure Required Casing type Split Design pressure of turbine casing 1.25 times rated pressure Method of cooling of turbine nozzles and blades By bleeding air from

compressor Method of cooling turbine casing By external fans Turbine wash/cleaning arrangements Required Bearings a) Type of radial bearing Spherical / Journal b) Type of thrust bearing Kingsbury or equivalent Gas turbine shaft glands type Labyrinth





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Method of sealing labyrinth From compressor bleed air Gas turbine shafts thrust indicator Required Mechanical bolt over speed trip provision Required NOx emission control Required NOx emission level ≤ 60 ppm @ 15% O2 when firing

Natural gas. ≤ 80 ppm @ 15% O2 when firing Distillate Oil.

Air intake System Location Outdoor Duty Continuous Weather proof protection Required Intake air filter type Self cleaning type Expansion joints Required

High pressure compressors for creating pulse of air through the filter

Bidder to state

Silencer Required Quality of outlet air (dust size) to GT Less than 5 microns Filter elements Replaceable Walkways, ladders and access for the filter elements Required Inspection doors for clean air plenum Required Intake air silencer a) Location Inlet air duct b) Material Stainless steel/ Acoustic insulation Required Expansion joint a) Type Elastic b) Material Reinforced rubber Fuel System Fuel (Primary) Natural Gas





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Fuel (Standby) Distillate Oil Fuel Analysis As given in General Technical

Specification Liquid fuel atomisation Air atomisation (for continuous

operation) Aux. compressor for start-up atomising air Required Fuel pressure & flow regulator Required Provision for Nitrogen purging after machine trip Required Turbine Oil system Type of oil Mineral/synthetic oil Protection against fire hazard for oil piping around high temperature piping and around oil tank

Required to be provided by the bidder

Main Lube oil pump a) No. required One (1) b) Type of pump Positive

displacement/Centrifugal c) Type of drive GT Shaft driven/A.C. motor Auxiliary Lube oil pump a) No. required One (1) b) Type of pump Positive Displacement/

Centrifugal c) Type of drive AC motor driven Hydraulic oil pump (if required) a) No. required 2 x 100% b) Type of pump Positive

displacement/centrifugal c) Type of drive A.C. motor driven Jacking oil pump a) Number required 1 (one) b) Type of pump Positive displacement c) Type of drive AC motor driven Emergency oil pump a) No. required One (1) b) Type of pump Positive displacement type c) Type of drive DC motor driven





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Oil cooler a) No required Two (2) x 100% b) Type Lube oil/water heat exchanger c) Tube material Admiralty brass

Oil tank Electric heater to heat the oil in the tank during cold season

Required

Lube Oil & Control Oil Filters To be provided with standby

element (Duplex type)

Vapour extractors a) No. required Two (2) b) Type of drive AC motor driven c) Oil separators/mist eliminators Required Oil Purifier (Common for all 4 GTs)) Number No. One (1) Type - Centrifuge Capacity To Purify not less than 25% of

the total oil quantity in the lubricating systems of one unit per hour

Turning gear/ Ratchet Mechanism a) Type of drive for turning gear AC motor or hydraulic turning

drive b) Hand barring facility Required Exhaust Gas Ducting

Duct material Carbon Steel

Insulation material (Internal) Ceramic Wool

Liner material (Internal) ASTM A 176 TYPE SS 409

Outside surface temp. to be maintained 60°C at maximum ambient

temp.

Exhaust Silencer Required

Exhaust Stack height (Minimum) Meters 30





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1.7.0 GUARANTEES, REJECTION

Description Unit Data Particular Guarantees

Power generated as measured at generator terminals at 45°C, 60% RH and 1100 m above MSL

MW

NOx emission level (At 15% O2) for Natural gas ppmvd NOx emission level (At 15% O2) for Natural gas ppmvd Heat Rate at 45°C, 60% RH and 1100 m above MSL kJ/kWhr General Guarantees

Sensitivity of electro-hydraulic speed governing system including governor valves

%

Maximum increase in running speed in case of sudden total or partial load reduction

%

Absence of excessive vibration during operation of the turbine generator. Maximum effective vibration velocity measured at bearing housings.

mm/s

Guarantees for component life

Combustion Liner hrs

Transition piece hrs Turbine Nozzles hrs

Turbine Buckets hrs

Noise level @ 1.0 m from equipment outline dbA





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1.8.0 TECHNICAL DATA BY THE TENDERER

Description Unit Data General Manufacturer Model number No. of units Type Performance parameters of GTG at MCR for different ambient site conditions at 60% RH– with Natural gas Fuel

0°C 15°C 25.5°C 45°C

(Tenderer to provided similar data for 75% MCR and 60% MCR after award of contract)

Output at generator terminal with power factor of 0.8

MW

Total Auxiliary power consumption for GTG & auxiliaries

MW

Fuel (NG) consumption for fuel net calorific value

Sm³/hr

Heat rate for net calorific value Kcal/KWh

r

NOx level in exhaust gas ppm vd Inlet air pressure drop mbar Compressor outlet temp °C Compressor mass flow Kg/s

Pressure ratio

Air fuel ratio

Combustion chamber pressure drop mbar

Turbine inlet temperature °C Turbine exhaust gas pressure drop mbar

Turbine Exhaust gas pressure mbar Turbine exhaust temp. °C





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Description Unit Data Exhaust mass flow Kg/s

Exhaust gas enthalpy Kcal/kg Performance parameters of GTG at MCR for different ambient site conditions at 60% RH

0°C 15°C 25.5°C 45°C

- with Distillate Oil Fuel

(Tenderer to provided similar data for 75% MCR and 60% MCR after award of contract)

Output at generator terminal with 0.8 power factor

MW

Auxiliary power consumption for GTG & Auxiliaries

MW

Distillate oil consumption for fuel net calorific value

Sm3/hr

Heat rate for net calorific value Kcal/KWh

r

NOx level in exhaust gas ppm vd Inlet air pressure drop mbar Compressor outlet temp. °C

Compressor mass flow Kg/s

Pressure ratio Air fuel ratio Combustion chamber pressure drop mbar

Turbine inlet temp. °C

Turbine Exhaust gas pressure drop mbar Turbine exhaust gas pressure mbar Turbine exhaust temp. °C Exhaust mass flow Kg/s

Exhaust gas enthalpy Kcal/kg Operation data Hours of operation before inspection of Hot gas path

hrs





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Description Unit Data Time from startup to 100% base load (stage wise curves to be furnished)

Minimum load for continuous operation of GTG

Normal base Min. Hot start Min. Expected Frequency of major overhauls during base load

After ........ fired Hrs

Annual outage hours Annual available hours of continuous operation at base load

hrs

No. of starts permissible for annual operating hours above

hrs

Effect of additional starts on equipment life, beyond permissible number

hrs

Hours of operation before first major overhaul

hrs

Feed back on operation of similar sets supplied elsewhere

- Year of commissioning - Capacity and model - Total operating hours logged with Natural gas

hours

- First major overhaul carried out after

hours

- First hot gas path inspection carried out after

hours

- Healthiness of hot gas path after first inspection

- No. of unscheduled outage - Reason for unscheduled outages - History of spurious trips & shut- downs





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Description Unit Data - Average annual operating hours logged

Performance Correction Curves (All correction curves to be furnished)

Barometric pressure correction curve no.

For output For heat rate Ambient temperature correction curve no.

For output For heat rate Fuel calorific value correction curve no.

For output For heat rate Inlet air pressure drop correction curve no.

For output For heat rate Exhaust gas pressure drop correction curve no.

For output For heat rate Relative humidity correction curve no.

For output For heat rate Speed correction curve no. For output For heat rate Ageing factor correction curve no. For output For heat rate Direction of rotation looking from compressor end





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Description Unit Data Turbine speeds Rated speed rpm Idling speed rpm Ignition speed rpm Self sustaining speed rpm Over speed trip i. Electrical rpm ii. Mechanical rpm Turning gear speed rpm Critical speed for the GT alone i. 1st critical speed rpm ii. 2nd critical speed rpm iii.3rd critical speed rpm Critical speed for the complete rotor (assembly of gas turbine generator set)

i. 1st critical speed rpm ii. 2nd critical speed rpm iii.3rd critical speed rpm Coast down time to stand still condition (curves to be furnished)

For normal shutdown Min. * For trip condition Min. Cooling down period Hrs. Max permissible Bearing vibrations (peak to peak)

mm/sec

Max. permissible Shaft vibrations (peak to peak)

mm/sec

Max. permissible shaft eccentricity mm Max. noise level at a distance of 1.0 m from the equipment

dBA

Max / min. impurities acceptable in Natural gas & Distillate Oil to gas turbine inlet

Gas Distillate

Max. Min. Max. Min. Wobbe Index Lower calorific value kJ/kg Viscosity at 15°C CST





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Description Unit Data 30°C CST 50°C CST Water content % wt Sediment/ Particulate matter %wt Sulphur %wt Ash content %wt Calcium ppm Lead ppm Sodium ppm Potassium ppm Vanadium ppm Nitrogen %wt Nickel ppm Arsenic ppm Chlorides ppm Barium, manganese & phosphorous ppm Filterable dirt mg/100

ml

Carbon residue %wt C/H2 ratio Flash point °C Fire point °C Type of additive Type of inhibitor Layout Data Total size of gas turbine generator unit (l x w x h)

MxMxM

Weight of gas turbine generator a Gas turbine kg b Electrical generator kg c Gas turbine generator complete unit

kg

Weight of heaviest single piece of equipment during erection

kg

Space requirement for pulling the generator rotor beyond the gas turbine generator block

mm

Capacity of overhead crane for erection

Ton

Capacity of overhead crane/lifting tackle

a) For gas turbine maintenance Ton b) For pulling the generator rotor Ton Moment of inertia of all rotating masses connected to the generator shaft





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Description Unit Data * a) Generator b) Reduction gear c) Turbine-compressor rotor d) Auxiliary gear box e) Inertia constant Gas turbine Air compressor Type of compressor * No. of compressor stages No. of compressor casings Outlet air pressure and temperature bar/°C No. of bleeding points for supplying cooling and sealing air and their locations

Compressor speed rpm Quantity of air bled at points kg/s Pressure of air bled at points bar Air flow for turbine blade cooling Kg/s Type of air flow regulation at part load

*

Maximum expected air leakage from casing parting planes and tap-off locations

Kg/s

Permissible leakage rate % * Method of surge control * Type of fixing of blades to rotor disc * Type of fixing of rotor disc to rotor No. and type of bearings Lube oil flow to each bearing LPM Compressor washing/cleaning Method Washing agent Quantity of washing agent required per washing

m³





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Description Unit Data Capacity of storage tank m³ Recommended frequency of compressor washing

Fired hours

Recommended level of fall in electrical output for washing

MW

Materials of construction (full specification as per ASTM/BS/DIN or any other standard shall be mentioned)

Casing Rotor discs Rotating blades * Stationary blades Shaft Rotating blades shroud/lacing wire Casing bolts & nuts Bearing Protective coating material Expected life of hrs - blades hrs - bearings Normal rated power input to compressor

KW

Combustion System Natural

Gas Distillate oil

Type No. of combustion chambers No. of burners Natural

Gas Distillate oil

Design heat loading per combustion chamber

Kcal/hr

Fuel pressure at burner bar





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Description Unit Data Efficiency of combustor at design point

Pressure drop across combustor at 100% fuel firing rate at site output

bar

Materials of construction Combustion chamber Combustion wrapper Flame tubes Fuel piping Combustion chamber lining and coating material

Fuel burner Transition piece Gas Turbine No. of stages Type of casing Method of supporting casing Type of fixing for combustor burner Type of fixing of blades to rotor disc Type of fixing rotor disc to rotor No. and type of air seals used No. of air ports No. of intrascope points/viewing points and their position

Materials of construction (full specification as per ASTM/DIN/BS or any other standard shall be mentioned)

Turbine stationary blading (for various stages)

Turbine rotor blades (for various stages)

Turbine rotor disc Turbine shaft Turbine casing Turbine casing bolts & nuts





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Description Unit Data Turbine blades protective coating (for various stages)

*

Expected life of turbine blades and nozzles

Bearings No. and type of bearings in gas turbine

Optimum operating temp °C Max. operating temp. °C Lining material Min. pressure at which lube oil is required

bar

Quantity of lube oil per bearing lpm Axial thrust bearing Number * Type Optimum operating temp °C Max. operating temp. °C Lining material Min. pressure at which lube oil is required

bar

Quantity of lube oil required per bearing

lpm

Details of turbine blade washing (if applicable)

Washing agent Frequency of washing After

...fired hours

Recommended level of fall in electrical output for washing

KW

No of blades with protective coating Type of coating





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Description Unit Data Intake Air System Intake air filter Manufacturer Type of filter Design air flow Kg/s No. of filter elements Nos. No. of modules Nos. No.of filter elements/module Nos. No. of Tiers Nos. Air flow per filter element kg/s Air velocity - design m/s Particle size at filter outlet microns Media material Expected life of filter material hrs Method of cleaning the filters Temperature/ pressure of purging air

°C/bar

Flow of air Kg/s * Intake air silencer * * Location * Type Sound absorbent Baffle material No. of silencers Nos. Inlet air ducting Material of construction Size m x m x m Flow velocity in duct m/s





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MT9

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Description Unit Data Thickness of duct mm Particulars of inside protection with suitable coatings Whether ductings are suitably designed to prevent undue vibration?

Yes/No

Expansion joints - Type - Number Nos. - Material of construction Necessary galvanised supports provided

Yes/No

Turning vanes at all bends provided Yes/No Manholes/access doors for inspection provided

Yes/No

Governing system

Type of governing Steady state speed regulation % Temporary speed variation when full load is thrown off

%

Permanent rate of speed variation when full load is thrown off

% *

Speed drop characteristics and range of adjustment

Turbine Oil System Number of circulations (per hour) No. Lubrication oil system pressure bar Lubrication oil system capacity m³ Lubrication oil system flow rate m³/hr Temperature of oil at inlet to bearing °C Temperature of oil at inlet to bearing °C Hydraulic oil pressure bar Oil reservoir Total quantity of oil in the system m3 Capacity of the oil reservoir m3 Operating capacity of the oil reservoir between high and low

m3





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MT9

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EV

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Description Unit Data levels Following instruments provided - Level indicators - High and low level alarms - Temp. indicator Oil reservoir tank material Lube oil strainers - Type/make - Numbers Nos - Size of the mesh Microns * * - Material - Max allowable pressure drop bar Main lube oil pumps

Type/ make Number Capacity M3/hr Discharge pressure bar (g) Rotational speed rpm Drive motor rating type/make kw Whether flame proof construction Material of construction - Impeller - Shaft - Casing Auxiliary lube oil pump Type/ make Number Capacity M3/hr Suction pressure bar (g) Discharge pressure bar Rotational speed rpm Drive motor rating type/make KW Whether flame proof construction Material of Construction - Impeller - Shaft - Casing Yes/No Hydraulic oil pumps Type/ make Number Capacity M3/hr Suction pressure bar (g) Discharge pressure bar (g) Rotational speed rpm Whether flame proof construction Material of construction





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MT9

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EV

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Description Unit Data - Impeller - Shaft - Casing Jacking oil pump Type/ make Number Capacity M3/hr Yes/No Suction pressure bar (g) Discharge pressure bar (g) Rotational speed rpm Drive motor rating type/make KW Whether flame proof construction Material of construction - Impeller - Shaft - Casing Emergency lube oil pump (DC motor driven)

Type/ make Number Capacity m3/hr Discharge pressure bar (g) Speed rpm Continuous motor rating Motor type/make (Motor details to be furnished Motor data sheets)

Oil coolers Type/ Make No. of coolers No. operating during full load operation

Oil capacity of each cooler m3/hr Oil side pressure drop bar Oil temperature - Inlet / outlet °C/°C Water flow through each cooler m3/hr Water temperature - Inlet / outlet °C/°C Water side pressure drop bar Water side drop at 10% tubes in plugged condition

Cooling surface area m² Materials of construction - Shell - Tube * - Tube sheet Location of the oil cooler assembly Tube removal space required Drain and vent connection with pad locked

m





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MT9

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EV

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Description Unit Data valves provided Weight of cooler i. Dry weight Kg ii. Wet weight Kg

Oil filters Lube oil Hydraulic

filter oil filter Type Make Nos offered Filtration size microns Design flow rates m3/hr Pressure drop bar Oil Purifier (Portable) Lube oil Hydraulic filter oil filter Manufacturer - Number No. Type - Capacity % Heater rating kW Rating of drive kW Turning Gear or Barring system

Type/Make Barring speed rpm Power required (if motor driven) Starting Device

Type/Make Output rating KW Detailed write-up on the starting device shall be furnished

Reduction Gear box (Between Gas Turbine and Generator)

Make/ Type/Design code

Input shaft speed rpm

Output shaft speed rpm

Efficiency %

Lubricating oil requirement l/s

Maximum permissible shock loading Service factor

Designed power transmission capacity

MW





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Description Unit Data

Weight Kg

Material of construction

Shafts Pinion Gears Casing Couplings Between Gas

Turbine & Accessory Gear

box

- Lubricating oil quantity (if required)

lpm

- Material of construction - Rating MW - Service factor - Efficiency % - Weight kg * - Design code

GT Exhaust Ducting Welded / Bolted Type Design & fabrication code Gas flow Operating (at 0°C/15°C/30°C) kg/sec. Design kg/sec Design pressure mbar Max. allowable back pressure mmwc Gas temperature Operating (at 0°C/15°C/30°C) °C Design °C Gas path dimension Gas path area m² Gas velocity m/sec Pressure drop (at 0°C/15°C/30°C) mmwc Pressure drop at design flow mmwc Constructional details External Duct plate Manufacturer - sides / bottom / top Material - sides / bottom / top mm Thickness - sides / bottom / top mm Corrosion allowance - sides / bottom / top

mm

Coefficient of expansion mm/mm °C Design metal temperature °C Internal liner Manufacturer Material - sides / bottom / top mm





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Description Unit Data Thickness - sides / bottom / top mm Corrosion allowance - sides / bottom / top

mm

Coefficient of expansion mm/mm °C Design metal temperature °C Duct reinforcement members/ stiffeners

Manufacturer Material - sides / bottom / top Size Flanges Manufacturer Location Dimension (LxWxThick) mm Material Insulation Manufacturer Material No of layers Thickness per layer mm Insulation density kg/m3 Surface temperature of duct at design flow

°C

Loads (kg) Static Dynamic Thermal movement in all directions mm Forces and moments Turning vanes at all bends provided Yes/No Support type? Whether ductings are suitably designed to prevent vibration

Gas Turbine Exhaust Stack

Flow medium Gas flow quantity kg/sec

Stack Dimension Top of stack elevation m Stack dia mm Exhaust gas velocity m/sec External shell plate thickness

mm

Air gap mm corrosion allowances Side mm Bottom mm Top mm External shell material Internal shell material Insulation thickness material





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Description Unit Data Liner material Outside surface temperature of ducting to be maintained

°C

Design pressure mmWC Design gas velocity m/sec Design metal temperature °C

Gas Turbine Exhaust Silencer

Flow medium Noise data considered External shell material Absorption Insulation material Liner material Outside surface temperature of ducting to be maintained

°C

Design pressure mmWC

Non metallic Expansion Joints

Flow medium No. of Expansion joints considered and its location

Design pressure mmWC Thermal movements Axial mm Lateral mm Vertical mm Loads Static N Dynamic N Flange dimension Insulation material & density Cladding material Note : * In the data sheets indicate that the data may be furnished after award of contract.

All other data to be filled in by the Tenderer during Bid stage itself.