Report

TRAINING REPORT

RAMGARH GAS THERMAL POWER PLANT(RGTPP)

Rajasthan Vidhyut Utpadan Nigam Ltd. Jaisalmer

Submitted in partial fulfillment of the diploma engineering of (BTER) Govt. Polytechnic College Hanumangarh

Period of Training 8th June 2015 To 5th July 2015

GOVT. POLYTECHNIC COLLEGE HANUMANGARH

Submitted To:- Submitted By:-Sh.Karmveer Swai Singh H.O.D. Diploma 2 nd Year Mechanical Department Mechanical EngineeringGPC Hanumangarh GPC Hanumangarh

ACKNOWLEDGEMENT

I would like to acknowledge the officers and other staff member of Ramgarh Gas Thermal Power Plant.

I express special thanks to Chief Engineer : Z.A ATTARY Executive Engineer : Assistant Engineer : DALA RAM CHOUDHARY Assistant Engineer : TIKU RAM CHOUDHARY

for their valued time ,kind ,wise and illuminating advise during training period.

Swai Singh

Diploma 2nd Year

Mechanical Engineering

GPC Hanumangarh

RAMGARH GAS THERMAL POWER PLANT

Ramgarh gas thermal power station is the first gas thermal powerplant of Rajasthan. The first stage was commissioned on dated 15-11-1994

LOCATION

Ramgarh gas thermal power plant is situated near village Ramgarh,60 km away from Jaisalmer . The first unit of 3 MW is not in operation now . The present installed capacity of the plant is 270.50 MW

STAGE UNIT NO. CAPACITY COST (Rs.Crore) SYNCHORONISING DATE

|. GT-1 35.5 MW 180 12.01.1996

||. GT-2 37.5 MW 300 07.08.2002

ST-1 37.5 MW 25.04.2003

|||. GT-3 110 MW 640 20.03.2013

ST-2 50 MW 05.04.2014

OPERATIONAL PERFORMANCE OF PLANT PARTICULARS GROSS PLANT LOAD AUX.POWER GAS

GENERATION(LU) FACTOR(%) CONSUMPTION(LU) CONS.(1000SCM)

2006-2007 4041.440 41.75% 268.179 240483

2007-2008 4141.153 42.78% 551.61 248876

2008-2009 3486.782 36.00% 333.116 209782

2009-2010 3539.44 36.57% 279.029 213635

2010-2011 3028.85 31.29% 161.452 183482

2011-2012 5367.94 55.30% 95.796 297151

2012-2013 4979.06 51.44% 90.245 272967

2013-2014 6733.195 52.92% 607.423 398509

INTRODUCTION ABOUT RAMGARH GAS THERMAL POWER PLANT (RGTPP)

RGTPP is located near Ramgarh town at about 60 km fromdistrict head quarter , Jaisalmer (Rajasthan) , which is largest districtof the state . Its installed capacity is 270.50 MW . This plant islocated in largest state of India, based on area .

There are problem in maintaining desired quality standards in electric supply to Jaisalmer on account of excess losses because of longer transmission lines . To rectify above problem and to utilize available natural gas in this area RGTPP was established in this border district whose existing capacity is 270.50 MW .

seeing the increasing demand of electricity in thisregion for various purpose like for providing drinking water in desertarea , flood lighting on INDO-PAK border fencing etc. , the State Govt.found it essential to raise the capacity of RGTPP and thereforeRajasthan Vidhyut Utpadan Nigam Ltd. established here four moreunits in third and fourth stage of the project . In third stage , one gasturbine of 110 MW and one steam turbine of 50 MW capacitieswere installed . Fourth stage is under planning . In fourth stage , onegas turbine of 110 MW and one steam turbine of 50 MW capacitieswere installed .

FIRST STAGE :

This unit is capable inn electric generation usingboth gas and diesel as fuel . In power plant 12 underground tanksare constructed for storage of diesel having total capacity of 2520KLt . Necessary equipments for this power plant were supplied byBHEL(Bharat Heavy Electrical Ltd. ),and building construction wascarried out by Rajasthan State Bridge Construction Corporation.

in this stage only gas turbine (GT-1) is used whichincludes a single unit of 35.5 MW .

SECOND STAGE :

First unit of this power plant is being operated by opencycle system , resulting in higher cost on electricity generation .Reduction in cost is only possible when first unit is operated onCombined Cycle System . So under expansion programming of thisproject , work of installation of a gas turbine and a steam turbine istaken in hand . In this system , electricity will be generated by asteam turbine utilizing heat obtained from exhaust of gas turbinesthrough a Heat Recovery Boiler . Thus ,no additional fuel will berequired for operating Stem Turbine . Under stage-||, one GasTurbine Unit (37.5 MW) was commissioned and synchronized withthe grid on 07-08-2002 . The Steam Turbine Unit (37.5 MW) was alsocommissioned and synchronized with the grid on 25-05-2003 andthus the plant has been made operational in Combined Cycle modewith a total capacity of 110.5 MW .

THIRD STAGE : Under stage -|||, one gas unit of 110 MW commissioned

on 20.03.2013 and the steam unit of 50 MW has been synchronized on dated 05.04.2014.At present activities for the COD of the 50 MW STG unit is under way.

FOURTH STAGE :160 MW stage-\\/ Gas Thermal Power Project is under planning

stage . Under stage- \\/ , one Gas Unit of 110 MW and one Steam Unit of 50 MW capacities is under way .

Gas Transportation System :ONGC and IOCL are engaged in exploration of oil and natural gas depositsin western Rajasthan . GAIL (Gas Authority Of India Ltd.) laid down12diameter and 35 km long pipe line for supply of gas from Gamnewalabased gas collection plant to Ramgarh , which has been further extendedup to Dandewala gas field of Oil India Ltd. Total distance of Dandewalagas Terminal is approximately 67 km from Ramgarh Terminal . This pipeline is being maintained by GAIL .GAS , which is use in plant ,is mixture of different gas . Perchantage ofgas is as follows :

Availability of Water :Requirement of water for power plant is supplied through Sagar MalGopa branch of IGNP (Indira Gandhi Nahar Project) . For this a 27kmlong ,5.4 cusec capacity pipe line is laid from RD- 190 of SagarMal Gopa branch to power plant . For ensuring proper electricsupply requirements ,a sub station of capacity 2*250 KVA ,33/0.4 KV,and a pumping station has been established at RD-190 in additionto construction of water storage tank of capacity 77000m3 at powerplant .

GAS PERCENTAGE

NITROGEN 31.9064 %

METHANE 48.5668 %

CARBON DIOXIDE 18.8793 %

ETHANE 0.5009 %

PROPANE 0.0333 %

ISO- BUTANE 0.0285 %

N- BUTANE 0.0513 %

ISO- PENANE 0.0185 %

N- PENANE 0.0130 %

HEXANE O.OOOO %

TOTAL 100 %

Electricity Transmission System :To ensure efficient transmission of electricity generated in the powerplant , a 215 km long Ramgarh - Jaisalmer -Barmer line of 132 KV hasbeen laid .

Expected System Operation :In spite of unfavourable geographical conditions and availability oflower quality gas than required , expected electricity is beinggenerated in this power plant .The details of total energy generated from this power station duringlast fifteen years are as under : -

Year Energy Generated(MU)

1999-00 228

2000-01 229

2001-02 120

2002-03 221

2003-04 238

2004-05 361.13

2005-06 435.62

2006-07 404.14

2007-08 414.11

2008-09 348.67

2009-10

2010-11

2011-12

2012-13

2013-14

2014-15

BRIEF INTRODUCTION OF PLANT OPERATION

At RGTPP Gas to the turbines is being supplied through GAIL

from oil wells of ONGC and OIL ,which are the attached to discover

oil and natural gas recourses in Western Rajasthan . The quantity of

the gas is 6-8 Lac SCM per day . FROM GAIL Terminal gas is supplied

to Gas Booster Compressor(GBC motor)at pressure of 10-15 kg/cm2

and quantity of the gas is 6-8 Lac SCM per day . There are -----two---

----GBC motor in RGTPP . The work of the GBC motor is to compress

gas and to supply required quantity of gas for power production . In

compressing process by GBC the pressure of the gas increases from

10-15 kg/cm2 to 18-23 kg/cm2 . The output of the GBC motor is first

merged and then is divided further , before blowing into the

Combustion Chamber . There are three gas turbine in GTPP ,GT-

1,GT-2 and GT-3 . The blowing pressure is 18-23kg/cm2 .

Combustion Chamber is a place where ignition of fuel mixed

with air occurs with the help of the sparkplugs , the voltage on -----

both-------- of the sparkplugs 15000V DC . On combustion ,the gas

gets mixed with air than the gas will expand and air pressure

increases . The air exhaust on the gas turbine fans gas turbine starts

to rotate . There are three generators of 35.5 MW, 37.5 MW and 110

MW attached with GT-1 , GT-2 and GT -3 respectively, mounted on

the same shaft as the turbine .so GT-1 , GT-2 , and GT -3 Produces

35.5 MW ,37.5 MW and 110 MW electricity respectively .

The exhaust of GT is flue gases .the temperature of the flue

is near about 500deg C . This exhaust may also be relived into the

atmosphere with help of controlled valves . But this exhaust is taken

in use to produce electricity . So this power plant is called Combined

Cycle Power Plant . This exhaust (flue gas) of the gas turbine is

further passed into the Heat Recovery Steam Generator (HRSG).

It is boiler . Water circulating in drum is superheated with thehelp of flue gases . This superheated steam runs the Steam TurbineGenerator , so it is called unfired combined cycle .

The generator is mounted on the same shaft as of the ST-1 and ST-2

, produce 37.5 MW and 50 MW electricity . The steam which is

blowing on the gas turbine should be superheated .

Steam should be superheated so that

1. No Corrosion will occur ,

2. Enthalpy drop will be less .

Power generation is also done at low voltage because of the

insulation problem . If the power generation is done at high voltage

then there are following disadvantages

1. Losses will be more

2. Wire may burn out

3. High insulation will be required which is very costly .

POWER PLANT CYCLE

Ramgarh Gas Thermal power Station is Combined Cycle Power Station .

Open Cycle :When Gas Turbine (GT) exhaust is diverted into the

atmosphere due to no provision of HRSG (Heat Recovery SteamGenerator) or non availability of HRSG then it is called is running inopen cycle . In open cycle as a gas turbine high exhaust gas is notutilized for heat transfer in boiler so its efficiency will come down .

Combined cycle :

When Gas Turbine exhaust is diverted to HRSG in which hightemperature Gas Turbine exhaust gas passes through HP SuperHeater , HP Economizer , LP Evaporator ,LP Economizer , andCondenser Pre-Heater (CPH) thus heat of gas turbine exhaust getabsorbed by above series of tanks located inside the HRSG andtemperature of Gas Turbine exhaust which is about 570 deg C willcome down to 135 deg C .

By utilizing the heat of Gas Turbine exhaust HRSG (Boiler) generatesSteam which is used to run Steam Turbine Generator (STG) .

Thus we can generates an additional power (about 50 % of gasturbine) generation in Steam Turbine Generator without any extrafuel cost . Thus we can get 30 % extra efficiency by running the gasturbine in combined cycle . As gas turbine is operated on BraytonCycle principle and steam turbine is rotated on Rankine Cycleprinciple that is why it is called Combined Cycle .

Advantage Of Combined Cycle Process :

Decreases in capital cost per MW installed

High overall efficiency i.e. 48 %

Compact in size

Low man power required for its operation and maintenance

Low water requirement

Pollution Free atmosphere and clean works place

Low installation time

High reliability and flexibility of the plant

INTRODUCTION TO PLANT EQUIPMENTS

Combined cycle power plants are installed now days at many placesin our country .

1.0 GAS TURBINE EQUIPMENTS :-

1.1 Compressor :

The atmosphere air is compressed to the 17 stage compressor and before it passes through the filter . The compressor ratio is 10 and this is routed to the combustors .

1.2 Combustors :

The fuel (gas) is provided to ten equal flow lines ,each terminating ata fuel nozzle centered in the end plate of a ten separate combustionchamber and prior to being distributed to the nozzles ,that fuel isactually controlled at a rate consistent with the speed and loadrequirements of gas turbine . The nozzle introduces the fuel into thecombustion chambers where it mixes with the combustion air and isignited by the spark plugs . At instant when fuel is ignited in onecombustion chamber , flame is propagated through connectingcrossfire tubes to all other combustion chamber .

1.3 Transition pieces :

The hot gases from the combustion chambers expand into the tenseparate transition pieces and from there to the three stage turbinesection of the machine .

1.4 Turbine :

There are three stage of the turbine and each consists of row of fixednozzles followed by a row of rotating turbine buckets . In eachfollowing row of the jet is increased with an associated pressuredrop and in each following row of a moving buckets , a portion ofthe kinetic energy of the jet is absorbed as useful work on theturbine rotor .

1.5 Exhaust :After passing through the third stage buckets , the gases are directedinto the exhaust hood diffuser which contains a series of turningvanes to turn the gases from an axial direction , thereby minimizingexhaust hood losses . The gases then pass into the exhaust plenumand are introduced to atmosphere through the exhaust stack or tothe HRSG .

2.0GAS TURBINE SUPPORT SYSTEM AND THEIR EQUIPMENTS :2.1 Starting System :2.1.1 Diesel Engine :Diesel engine / starting motor /main generator with static frequencyconverter . Diesel or starting motor with torque convertor or maingenerator with SFC is used as a starting device for gas turbine . Wehave Detroit make diesel engine of 590 hp for starting purpose .

2.1.2 Torque Converter :It transfers torque for DG to Gas Turbine . It is a hydraulic couplingwhich transfers torque from zero speed to self sustaining speed ofGas Turbine (i.e. about 60 % speed) .

2.1.3 Accessory gear Box :It accommodates following equipments Main tube oil pump , Main hydraulic pump , Main fuel oil pump , Atomizing air compressor.

2.1.4 Hydraulic Ratchet :It rotates the turbine shaft when gas turbine is on cool down . It alsohelps while break away of Gas Turbine during starting . It consists ofa ratchet mechanism operated by hydraulic device . Oil is supplied bya DC driven positive displacement pump .

2.1.5 Jaw Clutch Mechanism : It transmits power from Diesel Engine or Ratchet Mechanism to Gas Turbine through Torque Converter.

2.2 Lubricating Oil System :Major equipment of the system are :-

2.2.1 Oil Reservoir : The capacity is 3300 gallons . The total system requirement is 3500 gallons .

2.2.2 Lubricating Pump :Main lube oil pump is accessory gear driven. also for starting a/cpower driven lube oil pump of 175 m head and 460gpm flow isprovided . For emergency purpose DC pump of 910m head and250gpm flow is provided . During emergency pump in service filterremain by pass .

2.2.3 Heat Exchanger : Two coolers are provided for cooling oil each of 100% capacity .

2.2.4 Gas Skid :The function of the gas conditioning skid is to supply gas to gas Turbine free from condensate and gas particles .

2.2.5 Scrubber :The function of the scrubber is to remove condensate from gas bycentrifugal action by the use of no. parting plates within thescrubber itself . There is provision of solenoid operated drain valvefor removal of condensate which is sensed by a level switch .

2.2.6 Filter : The function of filter is to remove any foreign particles from the gas and to supply totally clean gas . This filters are of cartridge type and replaceable if D.P. across the filter increases .

2.2.7 Pressure Control Valve :The function of the pressure control valve is to regulate down steam pressure up to 22 kg/cm2 if upstream pressure is more . This is the designed value for inlet the gas stop ratio control valve.

2.2.8 Condensate Tank :

All the condensate collected at the bottom of the scrubber is routed to the tank through drain piping . For this is level controller on the scrubber which will operate on maximum and minimum level scrubber

Air Intake System :

Filters :

There are 396 no. of filters connected in different rows . These filters are made of cellulose fiber .

Filter Cleaning :

Reverse pulse self cleaning system is provided for cleaning of these fibers . Processor air is used for these pulsations . Each row is given reverse pulse at fixed time interval and in predefined rotation .

Air Processing Unit :

Air from the compressor output is taken to finned tube cool it and is passed through the dryer for removing moisture .

2.3 Cooling and Sealing Air System :

Air for the bearing sealing is extracted from the 5th stage of thecompressor. Centrifugal removes dust and other foreign particles.Two centrifugal blowers are provided for turbine shell cooling .

2.4 Ventilating System :

Being a closed system , air circulation is provided by followingventilating fans in different compartments :

Accessory and gas turbine compartment vent fan-2 no .

Load gear compartment -2 no.

Gas valve compartment vent fan -1 no.

Load gear oil vapors fan -1 no.

2.5 Gas Turbine and Compressor cleaning system :Compressor washing skid consists of : Water tank with heaters Water pump Detergent pump Water wash valve (electrically operated) Rice hoper is provided at compressor suction for solid compound cleaning of compressor .

3.0 RREDUCING GEAR BOX : Gas Turbine speed is 5100 rpm , but generator speed is designed as 3000 rpm ,so reducing gear box is provided to reduce speed to 3000 rpm.

4.0 H.R.S.G. AND STEAM TURBINE EQUIPMENT :4.1 H.R.S.G : HRSG is a horizontal , natural circulation ,bid rum ,dual pressureunfired water tube boiler . It is designed to generate HP steam at 62kg/cm2 pressure and 483 deg C temperature with 59.9 t/hr steamflow .LP steam is generated at 5 kg/cm2 pressure and at saturatedtemperature with 10.9 t/hr steam flow . These HRSGs are havingfacilities of HP and LP bypass system 100% for both the circuits tomatch the rated parameters (pressure and temperature) whilestarting the HRSGs and to minimize the losses of water and heatwhile shutting down the m/c . These are also useful when STG tripsand to keep boiler in service .Major equipment of recovery boilers are : Diverter damper and its seal air fan , Super heater , Evaporator (HP & LP) , Economizer (HP-1 ,HP-2 & LP) , CPH , Stack (height) .

4.2 Steam Turbine :The HP Steam Turbine is drawn from HP steam header of HRSG 1 & 2.The HP Steam parameters of the HP steam are 60 kg/cm2 pressure and480 deg C temperature . The LP steam to turbine is drawn from LP steamheader of HRSG 1 & 2 . The LP steam parameters of LP steam are 4.3kg/cm2 and 148 deg C temperature .

4.3 Condensate Circuit Equipment :It consists of condensers , ejectors ,extraction pumps ,gland steamcondenser .

4.3.1 Condenser :It is a two pass condenser having 9084 no. of tubes having coolingsurface area of 3070 m2 . It has steam condensing capacity of 137 t/hr,cooling water flow of 7050 m3/hr .

4.3.2 Ejectors :Two no. of two pass ejectors are provided each having a capacity ofhandling 15 kg/hr dry air 49 kg/hr air- water vapor mixture . Onestarting ejector is also there of 220 kg/hr of dry air handling capacityat a suction pressure of 0.33 atmosphere .

4.3.3 Extraction Pumps :Two no. of pumps each of 100 % capacity in the system . Each has acapacity of 95 m head and 186 m3/hr flow .

4.3.4 Gland Steam Condenser :Steam leaking from turbine glands is used to raise the temperatureof the condensate by GSC . Two no. of fans are provided forextracting steam .

4.4 Feed Water Circuit :It consists of the feed water tank ; HP & LP feed water pumps .

4.4.1 Feed Water Tank :It is mounted mounted at elevation of 9 m so it is provides a netpositive suction head to the boilers feed pumps . It is also has adearator at the top of the tank for mechanical dearation of the feedwater .

4.4.2 HP Feed Pumps :

Three feed pumps of 50 % duty are provided to feed H.P. water to theboiler . Each is a KSB make , multistage pump with discharge head of925 m and 75 m3/hr .

4.4.3 LP Feed Pumps :

Three feed pumps of 50 % duty are provided to feed L.P. water to theboiler . Each is a Beacon water make , multistage pump withdischarge head of 117 m and 11.5 m3/hr

5.0 COMMON SUPPORT SYSTEM FOR GT AND ST :

5.1 CW and ACW System :

There are three CW pumps each of 50 % capacity of 23 m head and3850 t/hr flow . The circulate water in steam turbine condenser andST oil cooler . There are three ACW pumps each of 50 % capacity of34 m head and 576 t/hr flow . They circulate water in following gasturbine auxiliaries :

Diesel engine ,

Lube Oil coolers ,

Generator air coolers .

It also circulates in feed pump bearing , coolers of AC plant ,aircompressors ,ADU s and boilers water sample coolers .

5.2 Air Compressors :

Air is required for the following purposes :

For pneumatic operations of all control valves ,

At different maintenance work places for cleaning ,

If required it can be used for GT filter cleaning .

There are three kirlosker make horizontal, balanced opposed pistoncompressor each of 8.1 kg/cm2 head and 253 Nm cusec/hr air flow.Air from the receiver tank is directed to air drying unit to moisterfree .

5.3 Raw Water System :

Three no. of bore wells supply raw water reservoir from which istransferred to water treatment plant by use of raw water pumpseach of 125 t/hr flow capacity. Each bore wells is of @ 125 to 150t/hr flow capacity . Daily raw water consumption of the plant isaround 40000 t.

5.4 Laboratory :

Any power plant requires soft water and dematerialized water inlarge quantity. There are soft water plant (capacity7.2 t/hr*2) whichis used in the boiler water circuit. Apart from that, a continuouswatch is kept of water chemistry of HRSG water to keep itsparameters (such as ph and conductivity) within a specified range.

5.5 Fire Protection System :

It includes no. of water pumps, hallon & co2 bank, nozzle and pipingnet work, flame and smoke detectors and emulsifies. There are threetypes of water pumps :

Hydrant pump (Motor and DE operated) ,

HVWS pump ,

Jockey pump.

5.6 Black Start D.G Set :

In thee event of total power failure, GT can be started with the helpof diesel generating set (500 KVA, 680Amp. max) which is capable ofsupplying power to the bare minimum requirement of theauxiliaries of one gas turbine. Later, other auxiliaries can be startedwith the help of running gas turbine.

CONSTRUCTION DETAILS OF GAS TURBINE

1. COMPRESSOR SECTION

General :

The axial-flow compressor consist of the compressor rotor and theenclosing casing. The inlet guide vanes, the seventeen stage of therotor and stator balding and the two exit guide vanes are includedwith in the compressor casing.

In compressor, air is confined to the space between the rotor andstator balding where it is compressed in stage by a series ofalternate rotating (rotor) and stationary (stator) aerofoil-shapedblades. The rotor blades supply the force needed to compress the airin each stage and the stator blades guide the air so that it enters thefollowing rotor stage at the proper angle. The compressed air exitsthrough the compressor discharge casing to the combustionchambers. Air is exerted from the compressor for turbine coolingbearing sealing and , during start-up, for pulsation control.

Rotor :

The compressor rotor is an assembly of fifteen wheels two-stubshaft, through bolts, and the compressor rotor bulkhead. The firststage rotor blades are mounted on the wheel portion of the forwardstub shaft.

Stator :

The stator (casing) area of the compressor section is composed offive major sections :

a) Inlet Casing

b) Inlet Guide Vanes

c) Forward Compressor Casing

d) Aft Compressor Casing

e) Compressor Discharge Casing

2. COMBUSTION SECTION :

General :

The combustion system is the reverse flow type and comprises tencombustion chambers with liners, flow sleeves, transition pieces andcrossfire tubes. Flame detectors, crossfire tubes, fuel nozzle andspark plug igniters are also part of the complete system. Hot gases,generated fro the burning of fuel in the combustion chambers, areused to drive the turbine.

Combustion Chambers :

Discharge air from the axial-flow compressor enters the combustionchamber from cavity at the center of the unit. The air flowsupstream along the outside of the combustion liner towards the 1inner cap. This air enters the combustion chamber reaction zonethrough the fuel nozzle swirl tip (when fitted) and through meteringholes in the both the cap and liner. When the nozzles supplied arenot of the type fitted with a swirl tip, the combustion chambers arefitted with a tabulator system.

The hot combustion gases from the reaction zone pass through athermal soaking zone and then into a dilution zone where additionalair is mixed with a combustion gases. Metering holes inn the dilutionzone allows the correct amount of air to enter and cool the gases tothe required temperature. Opening located along the length of thecombustion liner cap provide a film of air for cooling the walls on theliner and cap. Transition pieces direct the hot gases from the linersto the turbine nozzles.

3. Spark plugs :

Combustion is a initiated by means of high-voltage, retractable-electrode spark plugs installed in two of the combustion chambers.This spring-injected and pressure-retracted plugs receive theirenergy from ignition transformers. At the time of firing, a spark atone or both of these plugs ignites the combustion gases in achamber. The gases in the remaining chambers are ignited bycrossfire through the tubes that interconnect the reaction zones ofthe remaining chambers. As rotor speed increases, chamberpressure causes the spark plugs to retract and the electrodes areremoved from the combustion zone.

RATING OF GAS TURBINES:GAS TURBINE-1

(GT-1)

GAS PRESSURE ( kg/cm2 ) 22 kg/cm2

HYDRAULIC OIL PRESSURE ( kg/cm2 ) 80 kg/cm2

GENERATOR BEARING PRESSURE ( kg/cm2 ) 0.5 kg/cm2

RATIO VALVE GAS PRESSURE ( kg/cm2 ) 16 kg/cm2

LUBE OIL PRESSURE ( kg/cm2 ) 2 kg/cm2

GAS TEMPERATURE ( deg C) 120 deg C

LUBE OIL TANK TEMPERATURE ( deg C ) 50-60 deg C

GENERATOR rpm 3000 rpm

GENERATOR TURBINE rpm 5000 rpm

GENERATOR VOLTAGE ( kilo volt ) 11 KV

TURBINE MW 35.5 MW

GAS TURBINE-2

( GT-2 )

GAS TURBINE-3

( GT-3 )









GENERATOR TURBINE rpm 5000 rpm


TURBINE MW 37.5 MW









GENERATOR TURBINE rpm 5000Rpm


TURBINE MW 110 MW

STEAM TURBINE GENERATOR

INTRODUCTION :Rajasthan Gas Thermal Power Plant Steam Turbo

Generator (STG-1) is of the capacity of 37.5 MW and STG runs inCombined Cycle mode utilizing waste heat of exhaust of GT-1 (capacity of 35.5 MW) and GT-2 ( capacity of 37.5 MW). Steam TurboGenerator (STG-2) is of the capacity of 50 MW and STG runs inCombined Cycle mode utilizing waste heat of exhaust of GT-3 (capacity 110 MW).

In such Combined Cycle Power Plant higher thermal efficiency isachieved as compared to coal based thermal power plant. Briefintroduction of the parts/equipment of the STG power plant is asfollows :

1. Turbine :The function of the turbine is to drive the generator at a

speed of 3000 rpm. The heat energy of steam (enthalpy) isconverted in mechanical energy as steam expands in turbine. Beforeentering the main stream in turbine it passes through emergencystop valve and control valve located at turbine floor, there are 53stage in turbine, one stage consists of a set of fixed blade mountedon inner casing and rotary blade mounted on turbine shaft. LPinjection is connected after 43 stage of turbine. The turbine shaft issupported by the front bearing (Journal and thrust bearing) and therear bearing (Journal bearing). The axial thrust produced in themoving blades is balanced by balancing drum located in the frontside of turbine. The residual thrust forces of turbine that have notbeen compensated by balancing piston are taken up by the frontthrust bearing. The rear bearing of turbine houses the oil hydraulicturning device used for running the turbine on bearing gear. Turbinegland sealing is done to avoid air entry initially at both gland ends atin running to seal the LP end gland. When turbine is running sealingis done through turbine leak steam itself and balance steam flows tocondenser.

1.1 Turbine Oil System :

1.1.1 Main Oil Tank (MOT) :

MOT is located on 5 m. it serves for storing the oil volume requiredfor governing and Lubrication system. Oil vapor in oil tank arevented out by an oil vapor exhaust fan installed at the top of MOT.The MOT is provided with oil centrifuge inlet connection at bottomand the oil centrifuge return is connected back to oil tank. The oilcentrifuge cleans the oil stored in MOT.

1.1.2 Main Oil Pump (MOP) :

Lubrication oil needed for turbine bearing, governing oil system andbarring gear is supplied by MOP. The bearing Lubrication oil issupplied after cooler and duplex filter but governing oil and barringgear oil flows directly from the MOP discharge header.

Discharge Pressure - 10.2 kg/cm2

Flow - 150 m3/hr

Motor rating - 55 KW, 93A

Standby pump comes inn service at header pr. Below - 6.5 kg/cm2

1.1.3 Emergency Oil Pump (EOP) :

In the case of tripping/non availability of MOP, EOP server forsupplying oil for bearing cooling. The emergency oil pumps cuts inautomatically when oil header pressure falls below 0.9 kg/cm2 in theevent of further pressure fall in header, Oil shell be fed from anoverhead oil tank placed about 6.5 m over the turbine.

Turning operation is to be continued till the turbine rotor cools off.When AC power fails then turning operation is done by hand wheel,but EOP and JOP must be started at that time.

1.1.4 Jacking Oil Pump :

In the case of start up and shut down, on bearinggear it is necessary to supply the high oil pressure to lift the shaftingsystem slightly so as to avoid metal to metal contact. Frictionbetween shaft and bearing. For this purpose two nos. JOPS areprovided; one is AC-JOP and another is DC-JOP.

Discharge Pressure - 120 kg/cm2

Flow - 50 l/m

Motor rating - 18.9 KW, 33A (AC-JOP)

1.1.5 Turbine Design Rating :

Rated output - 38.7 MW

Maximum output - 44.4 MW

Specified inlet steam pressure - 76.0ata

Max. permissible inlet steam pressure - 90.0ata

MS inlet temperature - 518 deg C

Max. permissible inlet steam temp. - 526.3 deg C

Exhaust pressure - 0.1ata or (-) 0.9kg/cm2 vacuums

1.1.6 Turbine Tripping :

Turbine over speed operated - 3300 rpm

Bearing temperature very high 120 deg C

2. Heat Recovery Steam Generator (HRSG) :

-------------- Two----------------- numbers of HRSG are established;one each for steam generation utilizing waste heat of exhaust gasesof ----------GT-1, GT-2--------------respectively. HRSG is naturalcirculation Unfired Steam Generator Feed water coming from BFPdischarge passes through the tube bunches of different modules ofheat transfer surface and gets heated by gas turbine exhaust flowingin surrounding duct.

HRSG has seven heat transfer surface as mentioned below :

1. High Pressure Super Heater

2. HP-Evaporator including HP drum

3. HP-Economizer for preheating the feed water entering in drum.These are three in nos.

4. LP- Super Heater

5. LP- Evaporator including LP drum

6. LP- Economizer

7. Condensate preheated (CPH) for heating condensate water beforeflowing to Deaerotar.

HRSG Tripping :

HRSG Tripping means closing of diverter damper and closing of MS(main supply) stop valve (MS 138 in case of HP steam and MS 23 incase of LP steam).

It is tripped due to following reasons :

a. HP drum level very low (-) 512 mm

b. HP drum level very high (+) 175 mm

c. LP drum level very low (-) 438 mm

d. LP drum level very high (+) 175 mm

e. Pushing of both emergency trip push buttons from annunciationpanel.

3. Generator :MW 40.8 Stator volt 11 KV

Pf 0.80 Stator Current 2677 A

MVA 51 Rotor volt 246 V

Rotor amp 717 A

Cooling air (which is further cooled by ACW water in air cooler

located at 0 m.)

4. Water & Steam Cycle Equipment :

The water is store in water storage tank from Sagar Mal Gopa branchof India Gandhi Nahar Project. Then water is supplied by pump orpipe. The following equipments are used :

(a) Deaerator :

It is two parts; one is Deaerating column whereDeaeration takes place in spray valve cum tray chamber andanother is Feed water storage tank, which is used, as waterreservoir tank with capacity of 27.5 m3. whole assembly is knownas Deaerator. Stream pegging is also done in Deaerator to increaseDeaeration, feed water temperature and BFP suction pressure.Condensate discharge through CPH (condensate preheater) comeshere in a chamber with 12 spray valve and 9 tray S and Deaerationtakes place. Air comes out of the vent and water flows down inreservoir feed water storage tank.

(b) HP BFP :

High Pressure Boiler Feed Pumps are in no. and two arecontinuously running for full load operation. Its full load parameteris as follows :-

Discharge pressure 133.5 kg/cm2

HP BFP trips at 120 kg/cm2 discharge pressure.

(c) LP BFP :

LP BFPs are similar in constructions and operation as HP BFPmentioned above but with very low capacity as compared to theHP BFP. Its full load parameter are as follows :

Discharge Pressure 15.28 kg/cm2

LP BFP trips at 14kg/cm2 discharge pressure.

(d) Condenser :

Turbine exhaust is connected to condenser. Condenser here used issurface condenser. Circulating water pump discharge water flowsthrough condenser tubes & cools steam in surrounding areascoming out of turbine. Hot wells is bottom part of condensateresulting from condensation of steam is collected and we can addmake up water here to compensate line losses of closed watercycle. The pressure at outlet of condensate is negative.

Condensate pressure (-) 0.9 kg/cm2

Condensate cooling water temperature 33 deg C

(e) Condenser Extraction Pumps :

Condensate Extraction Pump (CEP) are three in nos. and out ofthem two pumps run for full load operation. These vertical pumpsare used to facilitate pumping the condensate back to deaerator.Now condensate extracting out of CEP is heated injector glandsteam cooler, condensate preheated, deaerator and in economizerbefore reaching to steam generator so as temperature is increasedup to 140 deg and thermal efficiency is improved.

Discharge Pressure 14.8 kg/cm2

Flow 107 m3/hr

Full load current 123 A

Motor rating 75 KW

(f) Ejector :

Ejectors are used to create vacuum in condenser. Starting ejector ischarged initially to create fast vacuum. Starting Ejector basicallyconsist of a nozzle through which pressure energy of incomingauxiliary steam is converted in kinetic energy and passing throughhigh velocity it entails air from condenser and the exhausted airand steam flows to the atmosphere.

Whereas in main ejector auxiliary steam accelerating throughnozzle is also being utilized in heating CEP discharge condensateand the condensed steam flows to condenser through manualvalves in stead of being exhausted to atmosphere as in case ofstarting ejector.

(g) Condensate Preheater :Condensate preheater (CPH) is located as a last heat transfersurface in exhaust gas path before flowing to 70 m high stacks.Condensate water flowing in CPH tubes heated through exhaustgas.

CPH inlet water temperature 48 deg C

Outlet water temperature 94.7 deg C

5. HP bypass and LP bypass (HP BP & LP BP):HPBP and LPBP are used to bypass the turbine rolling parameter isachieved. HPBP line is tapped off from individual HRSG MS lineand valves are located at 5 m in front of condenser. Similarly LPBPline is tapped off from individual from HRSG (LP system) and onevalve is located in the front of condenser at 5 m and is behind thecondenser at separate platform. HPBP & LPBP dumps MS directlyto condenser after reducing pressure. Downstream temperatureare reduced in case of HPBP by spraying BFP discharge water.

HPBP / LPBP control valves on following protections

(1) HPBP / LPBP downstream pr. High 6 kg/cm2

(2) Condenser pr. (Vacuum) low 0.6 kg/cm2

(3) Condenser wall temperature high 200 deg C

HRSG Section :

High Pressure Boiler Feed Pump (HP-BFP) :

Low Pass Boiler Feed Pump (LP-BFP) :

SUCTION PRESSURE (kg/cm2) 3 kg/cm2

DISCHARGE PRESURE (kg/cm2) 120 kg/cm2

DP ACROSS SUCTION PRESSURE (MMWC) 800MMWC

BALANCE LINE PRESSURE (kg/cm2) 3 kg/cm2

A.C.W SUCTION PRESSURE (kg/cm2) 3.5 kg/cm2

A.C.W DISCHARGE PRESSURE (kg/cm2) 3.2 kg/cm2

A.C.W INLET TEMPERATURE (deg C) 32 deg C

A.C.W OUTLET TEMPERATURE (deg C) 32 deg C

MOTOR WINDING TEMPERATURE (deg C) 50 deg C

MOTOR BEARING TEMPERATURE (deg C) 50-70 deg C

Rpm 2972 rpm

KW 600 KW

SUCTION PRESSURE (kg/cm2) 2.5 kg/cm2

DISCHARGE PRESSURE (kg/cm2) 20 kg/cm2

FEED WATER TEMPERATURE INLET (deg C) 100 deg C

FEED WATER TEMPERATURE OUTLET (deg C) 95 deg C

D.P. ACROSS STRAINER (MMWC) 4000 MMWC

KW 20 KW

RPM 2930 rpm

STEAM TURBINE GENERATOR - 1(STG-1) :

HEADER PRESSURE (kg/cm2) 8.8 kg/cm2

LUBE OIL TANK TEMPERATURE (deg C) 50 deg C

AUXILIARY STEAM PRESSURE (kg/cm2) 11.2 kg/cm2

AUXILIARY STEAM TEMPERATURE (deg C) 180 deg C

CONDENSER VACUUM VALVE (kg/cm2) -0.92 kg/cm2

SEAL STEAM PRESSURE (kg/cm2) 0.3 kg/cm2

SEAL STEAM TEMPERATURE (deg C) 120 deg C

CEP HEADER PRESSURE (kg/cm2) 15 kg

CEP MOTOR CURRENT (amp) 95 amp

HPCV POSITION 0-100 %

LPCV POSITION 0-100 %

CONTROL OIL PRESSURE (kg/cm2) 8 kg/cm2

TRIP OIL PRESSURE (kg/cm2) 9kg/cm2

BEARING OIL PRESSURE (kg/cm2) 0.35 kg/cm2

BEARING OIL TEMPERATURE (deg C) 55 deg C

STEAM TURBINE rpm 3000 rpm


GENERATOR VOLTAGE (KV) 11 KV

TURBINE MW 37.5 MW

STEAM TURBINE GENERATOR 2 (STG-2) :

HEADER PRESSURE (kg/cm2) 8.8 kg/cm2

LUBE OIL TANK TEMPERATURE (deg C) 50 deg C

AUXILIARY STEAM PRESSURE (kg/cm2) 11.2 kg/cm2

AUXILIARY STEAM TEMPERATURE (deg C) 180 deg C

CONDENSER VACUUM VALVE (kg/cm2) -0.92 kg/cm2

SEAL STEAM PRESSURE (kg/cm2) 0.3 kg/cm2

SEAL STEAM TEMPERATURE (deg C) 120 deg C

CEP HEADER PRESSURE (kg/cm2) 15 kg

CEP MOTOR CURRENT (amp) 95 amp

HPCV POSITION 0-100 %

LPCV POSITION 0-100 %

CONTROL OIL PRESSURE (kg/cm2) 8 kg/cm2

TRIP OIL PRESSURE (kg/cm2) 9kg/cm2

BEARING OIL PRESSURE (kg/cm2) 0.35 kg/cm2

BEARING OIL TEMPERATURE (deg C) 55 deg C

STEAM TURBINE rpm 3000 rpm


GENERATOR VOLTAGE (KV) 11 KV

TURBINE MW 50 MW

6. Auxiliaries :

6.1 Circulating Water Pump (CW Pump) :

These are three in nos. and located in pump house. These pumpsare used for circulating water through condenser tubes so as tocondense the turbine exhaust steam


Flow 4500 m3/hr

Full load Current 43 A

Motor rating 400 KW, 6.6 KV

6.2 Auxiliary Cooling Water Pump (ACW Pump) :

These are two nos. and also located in pump house. These pumpsare used for following purpose :

i. BFG brig and seal water-cooling

ii. Generator air cooling

iii. Compressor lube oil cooling

iv. Turbine bearing oil cooling

v. In GT area gas booster compressor and atomizing air cooler ACWpumps along with CW pumps take suction from pump locatedunderground beneath them and return is cooled by cooling towers.


Flow 655 m3/hr

Full load current 215 A

Motor rating 125 KW, 415 V

WATER FEED SYSTEM TO HP & LP BOILERS

Temperature = 100- 150 deg C

Pressure = 13.41 kg/cm2 From DM- Water Plant

HP-BFP Motors LP-BFP Motors

To HP Boiler To LP Boiler

Pressure = 132.05 kg/cm2 Pressure = 19.81 kg/cm2

Temperature = 130.07 deg C Temperature = 121.02 deg C

Feed Water Tank

Deaerator

COOLING SYSTEM FOR CONDENSING STEAM

Air Out

Cooling

Tower

35 deg C

C.W. Pump

25 deg C

Make up

Line

C.E.P Pump

To CPH

Section

RE-HEATINGOF CONDENSED STEAM FOR RE-USE IN CYCLE

CPH Section CPH Section Gas Turbine

Last Exhaust

CPH 1 CPH 2

100-150 deg C Temperature =90.95deg C

13.41 kg/cm2 Pressure = 13.59 kg/cm2

Deaerator

From CEP Discharge

DATA CONTROL SYSTEM STEAM SUPPLY SYSTEM FOR POWER GENERATION

To Atmosphere

505 deg C

44 kg/cm2

2 kg/ cm2 Pr. = -0.88 kg/cm2

Temp.= 146 deg C

185 deg C

CW Inlet CW Inlet

CW Output CW Output

SHP STEAM

LP INJECTIONSTEAM

G E

GENERATION OF SUPERHEATED STEAM FROM LP BOILER


Temp. = 121.02 deg C Temp. = 187.39 deg C

Flow = 8.8 t/hr

From To Steam

LP-BFP Turbine

Flue Gases

From GT

Exhaust

NOTE : -

The exhaust temperature of superheater varies from 480 to520 deg C and pressure varies from 45-48 kg/cm2.

Flue gases path in :

LP Boiler LP Superheater LP Evaporater LP Economizer

Boiler

GENERATION OF SUPERHEATED STEAM FROM HP BOILER


Temp. = 130.73 deg C Temp. = 506.94 deg C

Flow=35.35t/hr

From To Steam

HP-BFP Turbine

Flue Gases

From GT

Exhaust

NOTE : -

The exhaust temperature of superheater varies from 480 to520 deg C and pressure varies from 45-48 kg/cm2.

Flue gases path in :

HP Boiler HP Superheater HP Evaporater HP Economizer

Boiler

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