thermal power plant at NTPC

A PRESENTATION ON SUMMER TRAINING AT – NTPC DADRI

PRESENTED BY- RICHA KHATRIEN- 4TH YEAR 1029021045

ABOUT NTPC• NTPC , the largest power Company in India, was setup in 1975 to

accelerate power development in the country.

• NTPC has installed capacity of 29,394 MW.

• It has 15 coal based power stations (23,395 MW).

• 7 gas based power stations (3,955 MW).

• 4 power stations in Joint Ventures (1,794 MW).

• Today NTPC contributes more than 3 / 5th of the total power generation in India.

ABOUT NTPC DADRI• It has energy generating capacity by – -coal based thermal plant is 1820 MW . -gas based thermal plant is 817 MW.• It has 6 units of coal based thermal plant . -4 units are of 210 MW & 2 units are of 490 MW capacity. • It has 6 units of gas based thermal plant . -4 units are of 130 MW & 2 units are of 154 MW capacity.• Grand Total capacity is 2637 MW.

SOURCES

• COAL SOURCE - Piparwara mines , Jharkhand• WATER SOURCE - Upper Ganga Canal, Mat Branch• GAS SOURCE - HBJ Pipe line

OPERATION OF THERMAL POWER PLANT

OPERATION MECHANISM

• 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 produceselectric Power.• The power generated is then transmitted .

MAIN AND AUXILIARY EQUIPMENT

• Coal handling plant• Pulverizing plant• Boiler• Ash handling plant• Turbine• Condenser• Cooling tower and pounds• Feed water heater• Economizer• Superheater and Reheater• Air preheater

COAL HANDLING PLANTRaw coal wagon – Coal is brought to the site through a wagon as per the requirement.

Junction tower - JTs are used where the conveyor has any angular deviation.

Primary crusher – The raw coal is crushed into fine pieces of 45mm grit. Primary crusher is also called Rotatory breaker since the coal is crushed by rotating plate.

The stone and unwanted coal are

rejected

Junction Tower

Mill Bunker – The 25 mm grit coal is crushed into very fine powder for feeding the boiler . We will have a spare bunker for each boiler.

Boiler

Stack & Reclaimer – It is used to store the powdered coal for

emergency purpose.

Atmospheric air –Through FD fan

PULVERISING PLANT

In modern thermal power plant, coal is pulverized i.e. ground to dust like size and carried to the furnace in a stream of hot air.

Pulverizing is a means of exposing a large surface area to the action of oxygen and consequently helping combustion .

BOILER

• A boiler or steam generator is a closed vessel to which water under pressure, is converted into steam.

• It is one of the major components of a thermal power plant.

• Always designed to absorb maximum amount of heat released in the process of combustion.

SUPER HEATER

• A device which moves last traces of moisture.• It helps in reduction in requirement of steam

quantity.• Steam being dry reduces the mechanical

resistance of turbine.• No corrosion at the Turbine blades.

ECONOMISER AND AIR PRE-HEATER

• They are such devices which recover the heat from the flue gases on their way to chimney and raise the temperature of feed water.

• Economiser raises boiler efficiency.

• Air Pre-heaters recover the heat from the flue gases leaving the economiser and heat the incoming air required for combustion.

CONDENSER

• Which condenses the steam at the exhaust of turbine.

• It creates a very low pressure at the exhaust of turbine, this helps in converting heat energy of steam into mechanical energy in the prime mover.

• The condensed steam can be used as feed water to the boiler.

PRIME MOVER (TURBINE)• A steam turbine is a mechanical device that extracts thermal energy

from pressurized steam, and converts it into mechanical energy.• About 86% of all electric generation in the world is by use of steam

turbines.• It has almost completely replaced the reciprocating piston steam

engine.• 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 output from the HPT is

reheated in a reheater and used to rotate IPT.• Low Pressure Turbine (LPT) : The Exhausted steam from the IPT is

directly fed to rotate the shaft of LPT• All the turbines are connected to a single shaft which is connected to

the generator.

GENERATOR

• The Synchronus Generator is used to generate power by connecting the shaft of the Turbine to the shaft of the generator which create the magnetic flux producing Emf.

• The generated voltage will generally 33 KV to 11 KV max.• the generated Voltage is stepped up by connecting Step up

transformer and is also used for auxilliary purpose.

COOLING TOWER• Remove heat from the water

discharged from the condenser so that the water can be discharged to the river or re circulated and reused.

• Air can be circulated in the cooling towers through natural draft and mechanical draft.

SWITCHYARD

A switchyard is a part of an electrical generation, transmission system. Switchyard transform voltage from high to low’ or the reverse, or perform any of several other important functions.

CONTINUE…OUTDOOR EQUIPMENTS• BUS BAR• LIGHTENING ARRESTER• BREAKER• CAPACITIVE VOLTAGE TRANSFORMER• EARTHING ROD• CURRENT TRANSFORMER• POTENTIAL TRANSFORMER INDOOR EQUIPMENTS• RELAYS• CONTROL PANNEL• CIRCUIT BREAKERS

Types of cooling

Types of cooling

1. Oil Natural Air Natural (ONAN)

oil and air flows naturally.

2. Oil Natural Air Forced (ONAF)

As natural air is not so efficient to cool down the oil and bring it to safe limits.

So air is forced on the radiating fins with help of fans installed below the radiator fins.

3. Oil Forced Air forced (OFAF) With further increase in load, more

heat is generated which necessitates forced cooling of oil.

Cooling of Transformer

• The oil helps cool the transformer.

• To improve cooling of large power transformers, the oil-filled tank may have radiators through which the oil circulates by natural convection.

• Very large or high-power transformers may have cooling fans.

• oil pumps and even oil-to-water heat exchangers.

• Large and high-voltage transformers undergo prolonged drying processes, using electrical sell-heating.

UTILISATION OF SECONDARY RAW MATERIAL (ASH)

• Construction of embankments and fills.

• Construction of road in sub-base.

• Manufacture of cement.

• Manufacture of bricks/blocks.

• Agriculture as soil amendment/source of essential plant nutrients.