VOCATIONAL TRAINING REPORT ON

COMBINED CYCLE POWER PLANT

ONGC TRIPURA POWER COMPANY

KURUKSHETRA INSTITUTE OF TECHNOLOGY AND MANAGEMENT

DEPARTMENT OF MECHANICAL ENGINEERING

SUBMITTED BY NAME: DEBASISH DAS ROLL: 2912471

INTRODUCTION

One of the largest Country-based Gas & Steam exploration and production company

Produces around 72% of North Eastern state's Electricity.

The OTPC CCGT Power plant is 726.6 MW power plant having 2 units (2×363.3)= 2(232.39+130.91)

(GAS+STEAM)

OTPC TRIPURA ASSET, PALATANA, TRIPURA Tripura is one of the main work centers of ONGC in

North-eastern region. On the based of ONGC newly planted OTPC is now larger

production of Electricity of 726.6 MW It is based at PALATANA, UDAIPUR with man power of

little more than 600.

COMBINE CYCLE POWER

PLANT

OVERVIEW: THERMAL POWER PLANT

COMBINE CYCLE POWER PLANT (CCPP)

Natural Gas - More versatile than coal & oil- Can be used in 90% of energy applications

Electricity

ABSTARCT The OTPC CCGT Power plant is 726.6 MW power plant

having 2 units. Each unit has 1 gas turbine and one 1 steam turbine. Rating of the gas turbine and steam turbine are 232.39

MW and 130.91 MW respectively in each unit. The total capacity per unit is 363.3 MW. Its so called Combine Cycle due to combination of Gas

Turbine & Steam Turbine.

COMBINED CYCLE GAS TURBINE:

• THE COMBINED CYCLE CONSISTS OF THE FOLLOWING TWO CYCLES:

BRAYTON CYCLE RANKINE CYCLE

BASIC CONCEPTS• CHEMICAL ENERGY STORED IN FOSSIL FUELS SUCH AS COAL, FUEL OIL OR NATURAL GAS IS CONVERTED SUCCESSIVELY INTO

THERMAL ENERGY

MECHANICAL ENERGY AND FINALLY

ELECTRICAL ENERGY • THE SIMPLE WORD EQUATION FOR THIS CHEMICAL REACTION IS:

FUEL + OXYGEN = HEAT + CARBON DI OXIDE + WATER

CONVENTIONAL POWER STATION

GAS TURBINE COMPRESSOR

CC 1

GAS

GAS

AIR FROM ATMOSPHERE

DRIVE

CC 2BYPASS STACK 2

BYPASS STACK 1HRSG 1

PUMP

STEAM TURBINE

HRSG 2CONDENSERCOOLING

WATER

GT GEN

ST GEN

SCHEME OF TYPICAL POWER PLANT - COMBINED CYCLE

BRAYTON CYCLE• THE IDEAL BRAYTON CYCLE CONSISTS OF FOUR INTERNAL

REVERSIBLE PROCESS: 1-2: ISENTROPIC COMPRESSION ( IN COMPRESSOS) 2-3: CONSTANT PRESSURE HEAT ADDITION 3-4: ISENTROPIC EXPANSION ( IN TURBINE) 4-1: CONSTANT PRESSURE HEAT REJECTION

TO INCREASE THE BRAYTON CYCLE EFFICIENCY

• THE BRAYTON CYCLE WITH REGENERATION OR RECUPERATOR.

• INTERCOOLING.• RE-HEATING• INTERCOOLING, RE-HEATING & REGENERATION

RANKINE CYCLE• IDEAL CYCLE FOR VAPOUR PLANTS WITH NO

IRREVERSIBILITIES & CONSISTS OF THE FOUR PROCESS: 1-2: ISENTROPIC COMPRESSION IN PUMP. 2-3: CONSTANT PRESSURE HEAT ADDITION IN BOILER. 3-4: ISENTROPIC EXPANSION IN TURBINE. 4-1: CONSTANT PRESSURE HEAT REJECTION IN CONDENSER.

TO INCREASE THE RANKINE CYCLE EFFICIENCY

• LOWERING THE CONDENSER PRESSURE.• SUPER-HEATING THE STEAM TO HIGH TEMPERATURE.• INCREASING THE BOILER PRESSURE.

CONFIGURATION OF CCGT PLANT THE COMBINED-CYCLE SYSTEM INCLUDES SINGLE-SHAFT &

MULTI-SHAFT CONFIGURATIONS. THE SINGLE SHAFT SYSTEM CONSIST OF ONE GAS TURBINE , ONE STEAM

TURBINE, ONE GENERATOR & ONE HEAT RECOVERY STEAM GENERATOR (HRSG).

KEY ADVANTAGES OF SINGLE-SHAFT ARRANGEMENTS: OPERATING SIMPLICITY, SMALLER FOOTPRINT, LOWER START-UP COST.MULTI –SHAFT SYSTEM HAVE ONE OR MORE GAS TURBINE-GENERATORS &

HRSG’S THAT SUPPLY STEAM THROUGH A COMMON HEADER TO A SEPARATE SINGLE STEAM TURBINE- GENETRATOR.

IN TERMS OF OVERALL INVESTMENT A MULTI-SHAFT SYSTEM IS ABOUT 5% HIGHER IN COST.

COMPONENTS USED IN POWER PLANT (GAS TURBINE)

• SCRUBBERS: FUEL PASSES THROUGH SCRUBBERS THROUGH 10 INCH HEADER TO REMOVE & TO CONTROL MAJOR DUST?DIRTY PARTICLES ALONG WITH LIQUID GASES.

• FLAME ARRESTER: IT IS USED TO AVOID ANY KINGD OF ACCIDENTAL FIRE & ANY ENVIRONMENTAL HAZARD CAUSES DUE TO GAS.

• GAS BOOSTING COMPRESSOR: INITIAL GAS IS PASSES THROUGH GBC FOR COMPRESSION TO THE REQUIRED INCREASE IN PRESSURE AND TEMPERATURE.

• COOLING TOWER: WATER IS USED A COOLING MEDIUM AT VARIOUS STAGES IN GAS BOOSTING CHAMBER SUCH AS LUBRICATION UNIT & BYPASS CHAMBER. THERE WERE 3 COOLING TOWERS FOR THE PURPOSE WITH 4 FANS.

CONFIGURATION FOR STEAM TURBINE• THE TURBINE IS A SINGLE SHAFT MACHINE WITH SEPARATE HP-IP (COMBINED) AND LP PARTS.

• THE INDIVIDUAL TURBINE ROTORS AND GENERATOR ROTOR ARE CONNECTED BY RIGID COUPLING.

• THE HP-IP CYLINDER HAS A THROTTLE CONTROL GOVERNING.

TURBINE GOVERNING SYSTEM:THE TURBINE HAS A HIGH PRESSURE ELECTROHYDRAULIC GOVERNING SYSTEM.

AN ELECTRIC SYSTEM MEASURES AND CONTROLS SPEED AND OUTPUT.

THE ELECTRIC SYSTEM OPERATES THE CONTROL VALVES IN THE ELECTROHYDRAULIC GOVERNING SYSTEM PERMITS RUN-UP CONTROL OF TURBINE UP TO RATED SPEED AND KEEPS SPEED SWINGS.

D.M. WATER PLANT• D.M STANDS FOR DE-MINERALIZATION OF WATER.1. TURBIDITY OF WATER IS REMOVED.2. REMOVES BACTERIA & OTHER MICROBES.3. NEUTRALIZES THE BASES & CONVERTS IT INTO

CORRESPONDING ACIDS.4. REMOVES THE ACIDIC IONS PRESENT IN THE WATER.5. THE FINAL STAGE, BALANCED REMOVAL OF IONS

TAKES PLACE USING A MIXED BED.