Punj Lloyd

Thermal Power Plant

By,Sadhana...

Engineer

At present, India’s total installed power capacity stands at 1,47,402.81MW. Of this, the contribution of each sources are

Thermal - 93,392MW

Hydro - 36,647.76MW

Nuclear sources - 4,120 MW

Renewable energy - 13,242.41 MW.

India’s power generation capacity 68% below target in 2009. There is a huge demand for power in FY10.It is expected to grow by 4.6% with a

capacity of 7,730 MW are likely in FY10.

Power Generation in 2008-09 & Requirement in 2010

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Mechanical Energy Electrical Energy

1. Thermal Station: The turbine is rotated by steam which is produced by the heat generated by burning fuel in a Boiler.

2. Hydel Power Plant: The mechanical energy is produced by inducing high pressure water through a nozzle onto the turbine.

3. Nuclear Power Plant: Nuclear power is power (generally electrical) produced from controlled (i.e., non- explosive) nuclear Reactions i.e. fission or Fusion.

Types of Power PlantsPunj Lloyd

The coal is brought and crushed to powder. This is feed to Boiler for producing heat In Boiler the water is converted to steam. In Super heater the moisture content is removed from the steam and that steam is

called super heated steam The superheated steam rotates the shaft of the High pressure turbine The Exhausted steam is sent to preheater and the steam then rotates the Intermediate

pressure(IP) Turbine The steam from the IP turbine is then feed to low pressure turbine. The turbine shaft is connected to the Generator, which produces Electric Power. The power generated is then Transmitted.

Operation MechanismPunj Lloyd

Thermal Power Plant

Power plant order is placed on EPC contract, which is divided into 2 parts

BOP includes supply , erection and commissioning of complete plant excluding Boiler, Turbine & Generator.

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EPC

BOPBalance of

plant 40% of total contract

value

CBOPCivil

contributes 25%

EBOPElectrical

contrbutes15%

BTG60% of total

contract value

Boiler, Turbine & Generator

MBOP Mechanical Contributes 60%

Boiler, Turbine & Generator includes supply, erection & commissioning of Boiler Turbine Generator

BTG constitutes Approximately 60% of total contract value

Balance of Plant is given as a separate contract which include supply, erection & commissioning of

Coal Handling Plant Water Handling Plant( water treatment) Ash Handling Plant Switch Yard Switch Gear

This constitutes Approximately 40% of total contract value

BTG & BOPPunj Lloyd

Boiler

Air

Air

Fuel HFO,LDO & Coal

Boiler

Fuel HFO,LDO & Coal

Dryer

Air compressor

FD Fan

Atmospheric Air

The boiler is fed with HFO and LDO initially to ignite the coal in the Boiler. Types of boilers:1. Water tube Boiler: A boiler in which water circulates in tubes heated externally by the

fire.2. Fire tube Boiler: Water is present in the drum inside the boiler and Hot air is

circulated around to maintain the temperature.

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• The fuel and air are feed from 2 directions to increase the efficiency

In a Thermal Power Plant generally 3 turbines are used to increase the efficiency. High Pressure Turbine(HPT): The superheated steam is directly fed to this turbine to rotate it. Intermediate Pressure Turbine(IPT): The out put from the HPT is reheated in a reheater(RH) and

used to rotate IPT . Low Pressure Turbine(LPT): The Exhausted steam from the IPT is directly fed to rotate the shaft of

LPT.

Turbine

Condenser

HPT IPT LPT

RH

Steam

Super Heater

Generator

Steam

Shaft

*All the turbines are connected to a single shaft which is connected to the Generator.

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The Synchronous Generator is used to Generate power by connecting the shaft of the Turbine to the shaft of the generator which cuts the magnetic flux producing Emf.

The Generated Voltage will generally 11KV to 20 KV max. The Generated Voltage is stepped up by connecting Step up transformer and is

transmitted and is also used for Auxiliary purposes.

Generator

Bus Duct

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Generator Transformer20KV to 400KV

SYNCHRONOUSGENERATOR

UAT20Kv to 6.KV

Unit Auxiliary Transformer: This transformer is used to step down the produced voltage and use for Auxiliary purpose.

Raw Coal Wagon- Coal is brought to the site through a Wagon as per requirement.

Wagon tippler-The coal is unloaded from the Wagon and is transported to crushers and for storage place through conveyor.

Junction tower- JT’s are used where the conveyor has any angular deviation.

Primary Crusher-The Raw coal is crushed into fine pieces to 45mm grit).

Primary crusher is also called Rotary Breaker since the coal is crushed by a rotating plate.

Secondary Crusher-The fine pieces of coal is crushed to powder (to 25mm grit)

Rejected- The stones and unwanted

coal is rejected

Coal Handling PlantPunj Lloyd

Stacker & Reclaimer- It is used to store the powdered coal for emergency purpose

Two way conveyor

Atmospheric air (Through FD fan)

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Junction Tower

Mill Bunker-The 25mm grit coal is crushed into very fine powder for feeding the boiler.

We will have a spare Bunker for each Boiler.

BOILER

Water in a Power Plant is used for

1. Production of Steam- for rotating turbine.

2. Cooling Purpose- For cooling of various equipment .

Water is recycled and used for various purpose:

Water Handling Plant(WHP)

3% of water is wasted during this process. Appx 4 cubic mt water is lost /day/MW

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Raw Water

Purified DM water

For cooling purpos

e

Steam

Condenser

Reservoir

Water Clarification

DM Plant(Demineralized Plant)

Chlorification &

Filtration

Various Equipment Cooling Water

Cooling Tower

CT

Auxiliary cooling Water (ACW)

DMCWP

DMCW Demineralized cooling Water

CWPCT CWP CWP

Steam to Water

Cool water from CWP

Condenser

Boiler

Steam

water

Cool water

Hot water

Hot WellDearator

25D 35D

25D 20D

PHE

Various Equipment

D-Degrees

CWP-cooling water Pump

PHE-Pre heat Exchange

Water Cycle

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The Ash from the boiler is collected in two forms:

1. Bottom Ash(Slurry):It’s a waste which is dumped into a Ash Pond

2. Fly ash: Fly ash is separated from Flue Gases in ESP(Electro static Precipitator).

Ash Handling Plant

Fly Ash & Flue Gases

Economizer ESP

Bottom ash(wet ash)

Ash Pond

Boiler

Cylo

Cement Factory

Economizer : Reduces the temperature

Chimney

Fly ash

Flue Gases

Flue Gases

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DCS-Distributed Control System

DCS- It merges all communication capabilities of IED’s across a network to perform protection,control,metering and Automation scheme.

Substation Automation-The systems used to monitor & control power systems It typically include Station

SW, HMI, Bay Control / Automation . Protection units, Protection devices, Telecommunication systems and interfaces, Data gateways, plus comprehensive engineering, Project management, maintenance and training.