Prepared by :Shubhra DhyaniBtech(EEE) III year0919221054
CONTENTS• Brief Profile of the company• Combined Cycle Power Plant• Working of Gas Power Plant• Heat Recovery Steam Generator (HRSG)• Plant Overview• Water Treatment Plant• Generator• Transformer• Switch Yard Description• Specifications• Merits & Demerits• Bibliography
Brief Profile of the company• Under IPGCL i.e. Indraprastha Power Generation Company Limited,3 Power Stations are in operation.They are as follows : 1)I.P STATION 2)RAJGHAT POWER HOUSE 3)GAS TURBINE POWER STATION (GTPS)• Under PPCL i.e. Pragati Power Cooperation Limited, one Power Station is in operation and it is: PRAGATI POWER STATION
STATIONS I.P STATION RAJGHAT GTPS PRAGATI POWER POWER STATION STATIONStation 247.5 135 282 330Capacity(MW)Units 3*62.5 (GT) + 2*67.5 (GT) 6*30 (GT) + 2*104 (GT) + 60 (ST) 3*34 (WHRU) 1*122 (WHRU)Year of 1967-71 1989-90 1986 & 1996 2002-2003CommissioningCoal NCL,BINA NCL,BINA GAIL HBJ GAIL HBJField/Gas Pipeline PipelineWater River Yamuna River Yamuna River Yamuna Treated water from Sen Nursing Home &Sources Delhi Gate Sewage Treatment PlantsBeneficiary VIP-South & Central & NDMC- NDMC,SouthAreas Central Delhi North Delhi VIP,DMRC Delhi
MISSION OF THE COMPANY• To make Delhi-Power Surplus• To maximize generation from available capacity• To plan and implement new generation capacity in Delhi• To set ever so high standards of environment Protection• To develop competent human resources for managing the company with good standards
Combined Cycle Power Plant• Combined Cycle Power Plant (CCPP) or Combined Cycle Gas Turbine plant (CCGT)• A gas turbine generator generates electricity and heat in the exhaust is used to make steam, which in turn drives a steam turbine to generate an additional electricity.• In CCPP ,a successful common combination is the Brayton cycle (in the form of a turbine burning natural gas) and the Rankine cycle (in the form of a steam power plant)
• The gas turbine is comprised of three maincomponents: a compressor, combustor and a turbine.• The air is, compressed in the compressor (adiabaticcompression-no heat gain or loss), then mixed with fueland burnt by combustor under constant pressureconditions in the combustion chamber.•The resulting hot gas expands through the turbine toperform work (adiabatic expansion).
Heat Recovery Steam Generator (HRSG)• The Heat Recovery Steam Generator (HRSG) is a horizontal, natural circulation, single pressure, water tube type steam generator with a single drum.• It is unfired type and uses Gas turbine exhaust gases as heat source.• It has been designed to generate superheat steam at a pressure of 41.5 kg/ cm2 and a temperature of 512 degree Celsius at a Main Stream Value (MSV).• It consists of following section : a) Superheater section b) Evaporator section c) Economizer section d) Condensate Pre heater (C.P.H) and components e) Steel chimney
Water Treatment Plant •The steam coming out of turbine is condensed and the condensate is feedback to the boiler as feed water. Some water may be lost due to blow-down, leakage etc and to make up these losses additional water called make up water, is required to be fed to the boiler. •The source of feed water contain impurities that could lead to scale formation. •The water is passed through alum-dosed clarifier which bonds impurities and thus removed. •Chlorine removes the algae and bacteria’s from the water. These processes takes place in clarifier from where water is sent to D.M Plant (De-mineralized plant).
ACTIVATED CARBON FILTER:Water from the clarifier first comes in the ACF. It absorbs some ofthe impurities.STRONG ACID CATION:It consists of resin named hydrocarbon. It removes the acidicimpurities. This is recharged by HCl acid.DEGASIFIER:Here the gases available in the water i.e. oxygen, carbon dioxideis removed upto 5-6%.STRONG BASE ANION:It consists of resin, OH-.It removes the basic impurities. It isrecharged by NaOH. The pH is 8.5-9.5.MIXED BED:It consists of both resin, acid and basic. pH is maintained about6.8-7.2.This is recharged by HCl & NaOH.
Generator•Generator converts the mechanicalenergy of turbine shaft into electricalenergy. Rotating field type generators areemployed which are ventilated by the fansof rotor shaft or separately driven fans.•At this power plant the requirementsof generator are:POLES=2FREQUENCY=50HzSPEED=120f/P=3000rpm•The class of generator under consideration is steam turbine-driven generators, commonly called turbo generators. Generallythey have the ratings up to 1900MW but here 3000rpm,50Hzgenerators are used of capacities 122MW.
Transformer •Transformer is a device that transforms electrical energy form from one alternating voltage to another alternating voltage without change in frequency. •IEEE defines transformer as a static electrical device, involving no continuously moving parts, used in electric power system to transfer power between circuits through the use of electromagnetic induction.•Types of transformer:1) Power Transformer2) Instrument Transformer3) AutoTransformer4) On the basis of working
1) Power Transformer2) Instrument Transformer3) Auto Transformer4) On the basis of working 4.1) Step down- converts H.V to L.V 4.2) Step up- converts L.V to H.V
SWITCH YARD DESCRIPTION• For any power station, switchyard is an important part which bridges the generating station and the distribution system i.e. via switchyard the generated electricity is fed to the sub-stations. It connects the GTPS to the northern grid.• The switchyard of Gas Turbine Power Plant is of 66KV.• The voltage generated is 11KV, which is then step up to 66KV by generator transformer. This 66KV is fed to the 66KV switchyard.• The switchyard has the double bus bar system i.e. one is main bus and the other one is secondary bus.• Some of the functions are: Change voltage from one level to another Switch transmission and distribution circuits into and out of the grid system. Measure electric power qualities flowing in the circuits. Eliminate lightning and other surges from the system.
• ISOLATORS: They are designed to open a ckt under no load. Its main purpose is to isolate portion of the ckt from the other & is not intended to be opened while current is flowing in the line.• CIRCUIT BREAKERS: It is a piece of equipment which can break the circuit automatically under faulty conditions and make the circuit either manually or by remote control under faulty conditions. They can be classified asiii. oil ckt breakeriv. Gas(SF6) ckt breakerv. Air-blast ckt breakervi. Vaccum ckt breaker The switch yard has gas (SF6) or Sulphur Hexa Fluoride ckt breaker.
3)INSULATORS: All the insulators are made of porcelain metal parts. They are free from radio interference. They support the conductors (bus bar) and confine the current to the conductors.4)BUS COUPLERS: Breakers are used as a bus coupler. They provide coupling between the two bus bar of zones.5)CURRENT TRANSFORMER: C.T is an instrument t/f used for protection & metering of high values of currents. C.T is used for reducing a.c from higher to lower value of measurement/protection/control.
6) POTENTIAL TRANSFORMER: They are used to increasethe range of voltmeters in electrical substations andgenerating stations. They are also called voltage t/f.7)LIGHTINING ARRESTORS: It is a protectivedevice used to protect the station, equipmentsagainst atmospheric discharge.8)EARTHING LINKS: SwitchyardEarthing is provided to protectpersonally from shocks andhazards from electricalequipments.9)MULSIFIER: They are used to protect the transformer against fire.
SPECIFICATIONS• Specifications of SF6 circuit breaker:2) Rated voltage 72.5kV3) Rated frequency 50Hz4) Rated current 2000A5) Impulse voltage (peak) 325kV6) Rated breaking capacity a) Symmetrical 25KA b) Asymmetrical 28KA c) Making (peak) 64KA d) Short time (for 1 sec) 2.5KA11) Rated Pressure 5.5 bars12) Total mass of ckt breaker 900kg13) Total SF6 gas content 3.7kg
• Specifications of 66KV Isolators and earthing switches:2) No. of Pole 033) Installation Outdoor4) Rated Voltage 72.5KV/66KV5) Rated Current 1250 Amp6) Rated Frequency 50 Hz• Specifications of 66KV Current Transformer:8) No. of Course 49) Rated Voltage 72.5KV/66KV10) Rated Current 2000-100011) Rated Frequency 50Hz12) Total Creep age distance 1700mm13) Short time Current Rating 25 KV for 1 sec
• Specifications of Potential Transformer:2) Type WH 72.5-173) Standard IEC4) Year of manufacturing 19865) Weight 300kg6) Minimum Temperature 10 degree Celsius7) Maximum Temperature 50 degree Celsius8) Frequency 50Hz9) Voltage factor 1.510)Maximum Rating 1000-500 VA• Specifications of 66KV Lightning Arrestor:12)Rated Voltage 60KV13)Power frequency Reseal Voltage 60KV14)High Current Impulse 100 K Amps15)Class of Arrestors 10 K Amps for heavy duty16)Total creep age distance 1700mm
Merits & Demerits• Merits: Low operation and maintenance cost Less space is occupied Less gas storage Cheaper fuels like natural gas• Demerits: Temp. of combustion chamber is too high, which results in shorter life time. Gas turbine has low thermal efficiency Has starting problem Efficient only in combined cycle
Bibliography• Links referred : http://www.hrsgdesign.com/design0.htm http://ipgcl-ppcl.gov.in/http://www.osha.gov/SLTC/etools/electric_power/illustrated_glossary/substation.html#Equ ipment