Prepared by :Shubhra DhyaniBtech(EEE) III year0919221054

CONTENTSCONTENTS• 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 companyBrief 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 STATION2)RAJGHAT POWER HOUSE3)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 POWER STATION

GTPS PRAGATI POWER STATION

Station Capacity (MW)

247.5 135 282 330

Units 3*62.5 (GT) + 60 (ST)

2*67.5 (GT) 6*30 (GT) + 3*34 (WHRU)

2*104 (GT) + 1*122 (WHRU)

Year of Commissioning

1967-71 1989-90 1986 & 1996 2002-2003

Coal Field/Gas

NCL,BINA NCL,BINA GAIL HBJ Pipeline

GAIL HBJ Pipeline

Water Sources

River Yamuna River Yamuna River Yamuna Treated water from Sen Nursing Home & Delhi Gate Sewage Treatment Plants

Beneficiary Areas

VIP-South & Central Delhi

Central & North Delhi

NDMC-VIP,DMRC

NDMC,South 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 PlantCombined 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 main components: a compressor, combustor and a turbine.

• The air is, compressed in the compressor (adiabatic compression-no heat gain or loss), then mixed with fuel and burnt by combustor under constant pressure conditions in the combustion chamber.

•The resulting hot gas expands through the turbine to perform work (adiabatic expansion).

Working of Gas Power PlantWorking of Gas Power Plant

Heat Recovery Steam Generator Heat Recovery Steam Generator (HRSG)(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 PlantWater 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 of the impurities.

STRONG ACID CATION:It consists of resin named hydrocarbon. It removes the acidic impurities. This is recharged by HCl acid.

DEGASIFIER:Here the gases available in the water i.e. oxygen, carbon dioxide is removed upto 5-6%.

STRONG BASE ANION:It consists of resin, OH-.It removes the basic impurities. It is recharged by NaOH. The pH is 8.5-9.5.

MIXED BED:It consists of both resin, acid and basic. pH is maintained about 6.8-7.2.This is recharged by HCl & NaOH.

GeneratorGenerator•Generator converts the mechanical energy of turbine shaft into electrical energy. Rotating field type generators are employed which are ventilated by the fans of 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. Generally they have the ratings up to 1900MW but here 3000rpm,50Hz generators are used of capacities 122MW.

TransformerTransformer•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 Transformer

2) Instrument Transformer

3) Auto Transformer

4) On the basis of working4.1) Step down- converts H.V to L.V4.2) Step up- converts L.V to H.V

SWITCH YARD DESCRIPTIONSWITCH 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.

1) 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.

2) 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 as

i. oil ckt breaker

ii. Gas(SF6) ckt breaker

iii. Air-blast ckt breaker

iv. 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 increase the range of voltmeters in electrical substations and generating stations. They are also called voltage t/f.

7)LIGHTINING ARRESTORS: It is a protective device used to protect the station, equipments against atmospheric discharge.

8)EARTHING LINKS: SwitchyardEarthing is provided to protect personally from shocks and hazards from electrical equipments.

9)MULSIFIER: They are used to protect the transformer against fire.

SPECIFICATIONSSPECIFICATIONS• Specifications of SF6 circuit breaker:

1) Rated voltage 72.5kV

2) Rated frequency 50Hz

3) Rated current 2000A

4) Impulse voltage (peak) 325kV

5) Rated breaking capacity

a) Symmetrical 25KA

b) Asymmetrical 28KA

c) Making (peak) 64KA

d) Short time (for 1 sec) 2.5KA

6) Rated Pressure 5.5 bars

7) Total mass of ckt breaker 900kg

8) Total SF6 gas content 3.7kg

• Specifications of 66KV Isolators and earthing switches:

1) No. of Pole 03

2) Installation Outdoor

3) Rated Voltage 72.5KV/66KV

4) Rated Current 1250 Amp

5) Rated Frequency 50 Hz

• Specifications of 66KV Current Transformer:

1) No. of Course 4

2) Rated Voltage 72.5KV/66KV

3) Rated Current 2000-1000

4) Rated Frequency 50Hz

5) Total Creep age distance 1700mm

6) Short time Current Rating 25 KV for 1 sec

• Specifications of Potential Transformer:

1) Type WH 72.5-17

2) Standard IEC

3) Year of manufacturing 1986

4) Weight 300kg

5) Minimum Temperature 10 degree Celsius

6) Maximum Temperature 50 degree Celsius

7) Frequency 50Hz

8) Voltage factor 1.5

9) Maximum Rating 1000-500 VA

• Specifications of 66KV Lightning Arrestor:

1) Rated Voltage 60KV

2) Power frequency Reseal Voltage 60KV

3) High Current Impulse 100 K Amps

4) Class of Arrestors 10 K Amps for heavy duty

5) Total creep age distance 1700mm

Merits & DemeritsMerits & 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#Equipment