coal based thermal power plant

PRESENTATION ON

COAL BASED THERMAL POWER PLANT

Presented by Under

guidence off

Shivam kumar (ME-3th year) Mr. Amit

Sharma

Roll no -1147440098 Assistant

Professor

CONTENT

About plant.

Coal handling plant.

Boiler and their auxiliaries.

Condenser.

Cooling tower.

Feed water heater.

Turbines.

Deaerator.

Electrostatic precipitator.

Control room & Switchyard.

ABOUT PLANT

Aravali Power Company Private Limited (A Joint Venture of NTPC Ltd,HPGCL and IPGCL).

Project IGSTPP ( Indra Gandhi Super Thermal Power Project ).

The project is located at village Jharli in Jhajjar district ofHaryana,covering land area of 2191 acres.

Plant capacity :- Stage I : 1500MW(3X500MW) –Commission

Stage II: 1320 MW (2 x 660MW)- Future provision.

Equity sharing :- NTPC (50%), HPGCL (25%), IPGCL (25%).

COAL HANDLING PLANT

The function of coal handling plant is automatic feeding of coal to the

boiler furnace.

Coal is conveyed through rail wagon from out side of plant and through

conveyor system collected in hopper and ground to a very fine powder

by large metal spheres in the pulverised fuel mill.

Wagon Tippler Conveyor Coal Hopper Pulverised Mill

BOILER AND THEIR AUXILIARIES

Steam boiler or simply a boiler is basically a closed vessel into which

water is heated until the water is converted into steam at required

pressure. This is most basic definition of boiler.

Salient feature of 500MW boiler

Controlled circulation of water.

Uniform heating or cooling.

Better cleaning.

SUPER HEATER

Super heater is a component of a steam-generating unit in which

steam, after it has left the boiler drum, is heated above its

saturation temperature.

REHEATER

Some of the heat of superheated steam is used to rotate the turbinewhere it loses some of its energy.

Reheater is also steam boiler component in which heat is added to thisintermediate-pressure steam, which has given up some of its energy inexpansion through the high-pressure turbine.

The steam after reheating is used to rotate the second steam turbinewhere the heat is converted to mechanical energy.

This mechanical energy is used to run the alternator, which is coupled toturbine , there by generating electrical energy.

ECONOMISER

Flue gases coming out of the boiler carry lot of heat. An economiser

extracts a part of this heat from flue gases and uses it for heating feed

water.

This use of economiser results in saving coal consumption and higher

boiler efficiency.

Economiser tube assembly

AIR PREHEATER

After flue gases leave economiser, some further heat can be extracted

from them and used to heat incoming heat. Cooling of flue gases by 20

degree centigrade increases the plant efficiency by 1%.

Air preheater working

Working of boiler and their auxiliary

CONDENSER

Steam after rotating steam turbine comes to condenser. Condenser

refers here to the shell and tube heat exchanger (or surface

condenser) installed at the outlet of every steam turbine in

Thermal power stations of utility companies generally.

COOLING TOWERS

A condenser needs huge quantity of water to condense the steam .

Typically a 2000MW plant needs about 1500MGallon of water.

Small plants use spray ponds and medium and large plants use coolingtowers.

Cooling tower is a steel or concrete hyperbolic structure having areservoir at the base for storage of cooled water.

Height of the cooling tower may be 150 m or so and diameter at the baseis 150 m.

Natural draft cooling towers

FEED WATER HEATER

Feed water heating improves overall plant efficiency.

The dissolved oxygen and carbon dioxide which would otherwise cause

boiler corrosion are removed in feed water heater.

Thermal stresses due to cold water entering the boiler drum are avoided.

Quantity of steam produced by the boiler is increased.

Some other impurities carried by the steam and condensate, due to

corrosion of boiler and condenser are precipitated outside the boiler.

TURBINE

A steam turbine converts heat energy of steam into mechanical

energy and drives the generator. It uses the principle that steam

when issuing from a small opening attains a high velocity. This

velocity attained during expansion depends on the initial and final

heat content of the steam. This difference b/w initial and final heat

content represents the heat energy converted into kinetic energy.

These are of two types :-

Impulse turbine

Reaction turbine

Turbine full view

DEAERATOR

Deaerator is a contact type open heater in which dissolved oxygen in the

feed water is removed as much as possible by mechanical means.

In deaerator the feed water is heated by LP or VB steam (pressure: 2.5 –

3.5kg/cm2, temperature: 1400°C). Due to heating the partial pressure of

dissolved oxygen in feed water increases and solubility decreases to

considerable amount. Then by mechanical means dissolved oxygen is

released in air.

ELECTROSTSAIC PRECIPITATOR

From air preheater this flue gases (mixed with ash) goes to ESP. The

precipitator has plate banks (A-F) which are insulated from each other

between which the flue gases are made to pass. The dust particles are

ionized and attracted by charged electrodes.

The electrodes are maintained at 60KV.Hammering is done to the plates

so that fly ash comes down and collect at the bottom. The fly ash is dry

form is used in cement manufacture.

COMPLETE WORKING OF THERMAL POWER PLANT

REHEAT RANKINE CYCLE WORKING