Submitted By-

Name: Amay Jain

Branch: B.Tech Power System Engineering

Batch: 2011-2015

Roll No.: R630211007

SAP ID: 500016415

BRIEF PROFILE OF THE COMPANY

• PRAGATI POWER CORPORATION LIMITED IS AN UNDERTAKING OF

GOVERNMENT OF NCT OF DELHI. IT WAS INCORPORATED ON 9TH

JANUARY, 2001 TO UNDERTAKE POWER GENERATION ACTIVITIES

FOR SUPPLYING POWER TO DELHI. IT IS ONE OF THE LEADING

UNDERTAKINGS OF GNCTD, GENERATING PROFITS SINCE

INCEPTION AND PAYING DIVIDENDS REGULARLY. IT IS PRESENTLY

HAVING CAPITAL BASE OF 2,019 CRORES AND ASSET BASE

OF 3,319 CRORES. THE PROJECTED ASSET BASE AND REVENUE

INCOME OF COMPANY IN THE NEAR FUTURE ARE 6,000 CRORES

AND 5,000 CRORES RESPECTIVELY. THE FIRST PROJECT

UNDERTAKEN BY THE COMPANY WAS 330 MW GAS BASED CCGT

WHICH WAS FULLY COMMISSIONED IN THE YEAR 2003-04. THE

STATION IS PRESENTLY OPERATING AT ABOVE 85% AVAILABILITY.

VISION & MISSION

VISION:

• TO MAKE DELHI-POWER SURPLUS.

MISSION:

• TO MAXIMIZE GENERATION FROM AVAILABLE CAPACITY.

• TO PLAN & IMPLEMENT NEW GENERATION CAPACITY IN DELHI.

• COMPETITIVE PRICING OF OUR OWN GENERATION.

• 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 (CCPP)

• 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).

BRAYTON CYCLE• THE BRAYTON CYCLE IS A THERMODYNAMIC CYCLE THAT DESCRIBES THE WORKINGS

OF A CONSTANT PRESSURE HEAT ENGINE.

• IDEAL BRAYTON CYCLE:

1. ISENTROPIC PROCESS - AMBIENT AIR IS DRAWN INTO THE COMPRESSOR, WHERE IT IS

PRESSURIZED.

2. ISOBARIC PROCESS - THE COMPRESSED AIR THEN RUNS THROUGH A COMBUSTION

CHAMBER, WHERE FUEL IS BURNED, HEATING THAT AIR—A CONSTANT-PRESSURE

PROCESS, SINCE THE CHAMBER IS OPEN TO FLOW IN AND OUT.

3. ISENTROPIC PROCESS - THE HEATED, PRESSURIZED AIR THEN GIVES UP ITS ENERGY,

EXPANDING THROUGH A TURBINE (OR SERIES OF TURBINES). SOME OF THE WORK

EXTRACTED BY THE TURBINE IS USED TO DRIVE THE COMPRESSOR.

4. ISOBARIC PROCESS - HEAT REJECTION (IN THE ATMOSPHERE).

• ACTUAL BRAYTON CYCLE:

I. ADIABATIC PROCESS - COMPRESSION.

II. ISOBARIC PROCESS - HEAT ADDITION.

III. ADIABATIC PROCESS - EXPANSION.

IV. ISOBARIC PROCESS - HEAT REJECTION.

RANKINE CYCLE• THE RANKINE CYCLE IS A MODEL THAT IS USED TO PREDICT THE PERFORMANCE OF

STEAM ENGINES. THE RANKINE CYCLE IS AN IDEALIZED THERMODYNAMIC CYCLE OF A

HEAT ENGINE THAT CONVERTS HEAT INTO MECHANICAL WORK. THE HEAT IS SUPPLIED

EXTERNALLY TO A CLOSED LOOP, WHICH USUALLY USES WATER AS THE WORKING FLUID

• THERE ARE FOUR PROCESSES IN THE RANKINE CYCLE. THESE STATES ARE IDENTIFIED BY

NUMBERS (IN BROWN) IN THE ABOVE TS DIAGRAM.

• PROCESS 1-2: THE WORKING FLUID IS PUMPED FROM LOW TO HIGH PRESSURE. AS THE

FLUID IS A LIQUID AT THIS STAGE, THE PUMP REQUIRES LITTLE INPUT ENERGY.

• PROCESS 2-3: THE HIGH PRESSURE LIQUID ENTERS A BOILER WHERE IT IS HEATED AT

CONSTANT PRESSURE BY AN EXTERNAL HEAT SOURCE TO BECOME A DRY SATURATED

VAPOUR. THE INPUT ENERGY REQUIRED CAN BE EASILY CALCULATED USING MOLLIER

DIAGRAM OR H-S CHAR TOR ENTHALPY-ENTROPY CHART ALSO KNOWN AS STEAM

TABLES.

• PROCESS 3-4: THE DRY SATURATED VAPOUR EXPANDS THROUGH A TURBINE,

GENERATING POWER. THIS DECREASES THE TEMPERATURE AND PRESSURE OF THE

VAPOUR, AND SOME CONDENSATION MAY OCCUR. THE OUTPUT IN THIS PROCESS CAN BE

EASILY CALCULATED USING THE ENTHALPY-ENTROPY CHART OR THE STEAM TABLES.

• PROCESS 4-1: THE WET VAPOUR THEN ENTERS A CONDENSER WHERE IT IS CONDENSED

AT A CONSTANT PRESSURE TO BECOME A SATURATED LIQUID.

FUEL

• THE PRIMARY FUEL FOR GAS TURBINE IS NATURAL GAS BEING

SUPPLIED BY M/S GAIL THROUGH HBJ PIPE LINE.

• THE GAS IS RECEIVED AT GAIL TERMINAL INSTALLED IN THE

VICINITY OF THE POWER STATION.

• M/S GAIL IS COMMITTED TO SUPPLY 1.75 MCMD OF GAS ON DAILY

BASIS AT A PRESSURE OF 20 KG PER SQ. CM.

• THE CALORIFIC VALUE OF NATURAL GAS BEING RECEIVED FOR

POWER GENERATION IS IN THE BAND OF 8200-8500 KILOCALORIES.

THE SECONDARY FUEL FOR GAS TURBINE IS HSD/NAPTHA, WHICH

IS USED IN CASE NO GAS SUPPLY IS AVAILABLE. DEMINERIALIZED

WATER IS INJECTED TO CONTROL NOX. WHILE MACHINE IS

OPERATED ON LIQUID FUEL I.E. HSD/NAPTHA.

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

CONDENSER• THE SURFACE CONDENSER IS A SHELL AND TUBE TYPE OF HEAT

EXCHANGER IN WHICH COOLING WATER IS CIRCULATED THROUGH

THE TUBES. THE EXHAUST STEAM FROM THE LOW PRESSURE

TURBINE ENTERS THE SHELL WHERE IT IS COOLED AND

CONVERTED TO CONDENSATE (WATER) BY FLOWING OVER THE

TUBES.

DE-AERATOR• A STEAM GENERATING BOILER REQUIRES THAT THE BOILER FEED

WATER SHOULD BE DEVOID OF AIR AND OTHER DISSOLVED GASES,

PARTICULARLY CORROSIVE ONES, IN ORDER TO AVOID CORROSION OF

THE METAL. GENERALLY, POWER STATIONS USE A DEAERATOR TO

PROVIDE FOR THE REMOVAL OF AIR AND OTHER DISSOLVED GASES

FROM THE BOILER FEEDWATER. A DEAERATOR TYPICALLY INCLUDES A

VERTICAL, DOMED DEAERATION SECTION MOUNTED ON TOP OF A

HORIZONTAL CYLINDRICAL VESSEL WHICH SERVES AS THE

DEAERATED BOILER FEEDWATER STORAGE TANK.

COOLING TOWER• COOLING TOWERS ARE HEAT REMOVAL DEVICES USED TO TRANSFER PROCESS

WASTE HEAT TO THE ATMOSPHERE. COOLING TOWERS MAY EITHER USE THE

EVAPORATION OF WATER TO REMOVE PROCESS HEAT AND COOL THE WORKING

FLUID TO NEAR THE WET-BULB AIR TEMPERATURE OR RELY SOLELY ON AIR TO

COOL THE WORKING FLUID TO NEAR THE DRY-BULB AIR TEMPERATURE.

• AT PPCL, ID COOLING TOWERS ARE USED AND ARRANGED IN THE FORM OF A

ROW OF 8 CELLS SEPARATED BY BLOCK PARTITION WALLS FROM BASIN SILLS

TO THE FAN DECK.

• FANS ARE 8 BLADED EACH HAVING A DIAMETER OF 9144 MM

AIR FILTRATION SYSTEM• WE NEED FILTRATION OF INLET AIR TO PREVENT INGESTION OF CONTAMINANTS TO

AVOID EROSION, FOULING, CORROSION, HOT GAS PATH CORROSION ETC. FILTRATION CAN

REMOVE SOME, BUT NOT ALL SUBSTANCES LIKE OIL VAPOUR, SMOKE WHICH CAUSE

FOULING OF COMPRESSOR BLADES. THESE ARE NEEDED TO BE REMOVED BY ONLINE OR

OFFLINE CLEANING WASHING OF COMPRESSOR USING ASH FREE DETERGENTS.

• AIR CONSUMED BY 1 GT (FRAME 9 E) FROM ATMOSPHERE IS 435 KG/S APPROX.

• AIRBORNE DUST CONTAINS SODIUM & POTASSIUM TWICE AS IN SOIL, ARISES FROM FINE

PARTICLES OF SOIL, LEADS TO HOT CORROSION.

• ALSO CONTAINS HYDROCARBON FROM VEHICULAR POLLUTION AND NEARBY POWER

PLANTS.

• CONTAINS OTHER SOLID, LIQUID AND GASEOUS CONTAMINATIONS

BALANCE OF PLANT (BOP)

• 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.

GENERATOR• 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 REQUIREMENTS

OF GENERATOR ARE:

POLES=2

FREQUENCY=50HZ

SPEED=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.

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 TRANSFORMER

2) INSTRUMENT TRANSFORMER

3) AUTO TRANSFORMER

4) ON THE BASIS OF WORKING

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 220 kV.

• The voltage generated is 10.5 kV, which is then step up to 220 kV by generator

transformer. This 220 kV is fed to the 220 kV 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 circuit under no load. Its main purpose

is to isolate portion of the circuit 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 circuit breaker

ii. Gas(SF6) circuit breaker

iii. Air-blast circuit breaker

iv. Vaccum circuit breaker

The switch yard has gas (SF6) or Sulphur Hexa Fluoride circuit 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

transformer

7) LIGHTINING ARRESTORS: A lightning

arrester is a device used on electrical power systems

and telecommunications systems to protect

the insulation and conductors of the system from the

damaging effects of lightning. The typical lightning

arrester has a high-voltage terminal and a ground

terminal.

8) EARTHING LINKS: Switchyard

Earthing is provided to protect personally

from shocks and hazards from electrical

equipments.

SPECIFICATIONS

• GAS TURBINE:

COMPRESSOR STAGES -17.0

TURBINE STAGES-3.0

NUMBER OF COMBUSTORS-14.0

PRESSURE RATIO-12.6

FIRING TEMPERATURE (IN O C)-1124

GT SPEED (RPM)-3000

CAPACITY (IN MW)-104

NUMBER OF UNITS-2

GAS PRESSURE (IN KG/SQ. CM)-20

• STEAM TURBINE

H.P TURBINE -SINGLE FLOW WITH 28 REACTION STAGES

L.P. TURBINE-DOUBLE FLOW WITH 8 REACTION STAGES

H.P. STOP AND CONTROL VALVES-2

L.P. STOP AND CONTROL VALVES-2

RATED SPEED-50/S

MAX. SPEED (NO TIME LIMITATION)-51.5/S

MIN. SPEED (NO TIME LIMITATION)-47.5/S

CRITICAL SPEED (IN R.P.M)-1292/2492

H.P. STEAM FLOW (IN T/HR)-390

L.P. STEAM FLOW (IN T/HR)-80

GENERATING TRANSFORMERType of Cooling OFAF ONAF ONAN

HV Rating

(MVA)

114 79.8 57

LV Rating

(MVA)

114 79.8 57

No Load Voltage

(HV, kV)

230 230 230

No Load Voltage

(LV, kV)

10.5 10.5 10.5

Line Current

(HV, A)

28.16 200.32 143.08

Line Current

(LV, A)

6268.37 4387.86 3134.19

Class of Insulation : A

Temperature rise Oil : 35˚C

Temperature rise Winding: 40˚C

Conservator: Air Cell Type

Connection Symbol: YNd11

UNIT AUXILIARY TRANSFORMER

Type of Cooling ONAN ONAF

HV Rating (MVA) 16 20

LV Rating (MVA) 16 20

No Load Voltage HV

(kV)

10.5 10.5

No Load Voltage LV

(kV)

6.9 6.9

HV Line Current (A) 869.77 1099.71

LV Line Current (A) 1338.78 1673.48

Insulation Level : A

Temperature rise Oil : 50˚C

Temperature rise Winding: 55˚C

Conservator: Air Cell Type

Connection Symbol: Dyn1

GAS (SF6) CIRCUIT BREAKER

Rated Lightning Impulse

Withstand Voltage

1050 kV

Rated Short Circuit Breaking

Current

40 kA

Rated Operating Pressure 15 kg/cm2

Rated Duration of Short Circuit

Current

40 kA for 3 secs

Rated Voltage 245 kV

Rated Frequency 50 Hz

Rated Normal Current 3150 A

Rated Closing Voltage 220 V DC

Rated Opening Voltage 220 V DC

Rated Gas Pressure 6 kg/cm2

Rated Voltage and Frequency for

Auxiliary Circuit

415 V AC 50 Hz

VACUUM CIRCUIT BREAKER

Voltage 7.2 kV

Frequency 50 Hz

Normal Current 630 A

Sym Breaking Capacity 31.5 kA

Short Time Current 31.5 kA

Duration 1 second

Making Capacity 80 kAp

SINGLE LINE DIAGRAM OF SUBSTATION OF DELHI TRANSCO

LTD. (DTL)