rajwest thermal power plant

JIET School of Engineering & Technology for Girls

A

PRESENTATION

ON

THERMAL POWER PLANT

SUBMITTED BY:-

RAMA CHARAN

INTRODUCTION TO COMPANY RAJ WEST POWER PLANT, BARMER

Subsidiary of JSWEL is putting up a 1080MW lignite based coal pit head CFBC technology.

The required raw material (coal) will be made available from the nearby Jalipa and Kapurdi mines.

For the purpose of mining, a joint venture company (BLMCL) has been set up between Rajasthan State Minerals & Mining Ltd. and Raj West Power Limited.

This is the first and largest public Private partnership in the state of Rajasthan.

THERMAL POWER PLANT

General Layout of Thermal Power Station

In India 65% of total power is generated by the Thermal Power Stations .

Thermal power plant basically works on Rankine cycle.

RANKINE CYCLE:-

In thermal power station, water is heated, turns into steam and spins a steam turbine which drives an electrical generator. After it passes through the turbine, the steam is condensed in a condenser & recycled to where it was heated; this is known as Rankine cycle

Coal handling plant Coal conveyor pulverizer Boiler Super-heater and re-heaters Economizer Steam turbine generator Condensers Ash handling plant Generator Cooling tower Switch yard & Control room

Raw coal from Jalipa & Kapurdi

To R.W.P.L. frommine via railway

track

Wagon tipplers

Crusher houseCoal hopperbunkers

Raw coal feeders

Coal mills (pulverization)

Boiler furnace ( tangential firing of pulverized coal)

TRANSPORT OF COAL FUEL TO SITETRANSPORT OF COAL FUEL TO SITE

Thermal station use coal as the main fuel.

Raw coal is transported from coal mines ( Jalipa & kapurdi mines) to a power station site by trucks, Bulk cargo ships or railway cars.

Generally, when shipped by railways, the coal cars are sent as a full train of cars.

COAL PROCESSING

Coal is prepared for use by crushing the rough coal to pieces less than 2 inch (5cm.) in size.

Coal mills grind the larger of 2inch pieces to face powder and mix them with primary combustion air which transports the coal to the furnace and preheats the coal to drive off excess moisture content.

COAL STORAGE LIVE STORAGE:-

Coal is stored temporarily and may be withdrawn to supply combustion equipment with little amount.

This storage consists of about 24 to 30 hrs. of coal requirements of the

plant and is usually a covered storage in the plant near the boiler furnace.

DEAD STORAGE:-

Coal is stored for future use, and it is for longer period of time, about 40 days.

COAL CONYEYOR Coal conveyor is a belt type arrangement, that are used to move coal

efficiently.

Coal arriving by train can be stocked for later use or taken straight to the coal bunkers.

Control room with remote control system helps to ensure that conveyors take the coal to the right bunkers.Specification:

Belt width 1400mm

Speed 2.2m/sec

Total install power 360kw

Capacity 1350 Tones/hr

No. of conveyor 38

PULVERIZER

Each unit has six pulverizing fuel mills, each capable of pulverizing 40 tones of coal per hour

Inside the mills, ten giant hollow steel rollers crush the coal into a fine powder

Crushing the coal into a fine powder makes easier to burn it more completely

By pulverizing the coal combustion efficiency of coal increases.

BOILER A boiler or steam generator

is a closed vessel in which water is converted into steam, under pressure

It is the major components of a thermal power plant.

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

Boilers are of two types- Fire tube boiler Water tube boiler

SUPERHEATER

The steam produced in the boiler, goes to the steam drum and is then piped to super-heaters where it is heated above saturation temperature.

At this point steam is now turned into a very powerful source of energy.

This rotates the turbine to which generator is on the other end.

From rotating generator electricity is produced.

ECONOMISER

Economizer is device which recover the heat from the flue gases on their way to chimney.

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

An economizer extracts a part of this heat from flue gases and uses it for heating feed water.

This use of economizer results in saving coal consumption and higher boiler efficiency

ECONOMISER

REHEATERS

Reheater is also a steam boiler in which heat is added to this high-pressure steam, which has given up some of its energy in expansion through the intermediate-pressure turbine.

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

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

STEAM DRUM

STEAM TURBINE GENERATOR The turbine generator consists of a series of steam turbines

interconnected to each other and a generator on a common shaft.

There is a high pressure turbine at one end, followed by an intermediate pressure turbine, a low pressure turbines, and the generator.

As steam moves through the system, it loses pressure and thermal energy and expands in volume, requiring increasing diameter and longer blades at each succeeding stage to extract the remaining energy.

The entire rotating mass may be over 200 metric tons and 100 feet (30 m) long.

TURBINE

CONDENSERSteam after rotating steam turbine comes to the condenser. The purpose of condensor is to condense the outlet steam from steam turbine to get the condensed steam in the form of pure water.

This water is then Pumped back to the boiler.

DEAERATOR 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, power station uses a Deaerator, for the removal of air and other dissolved gases from the boiler feed water.A deaerator has a vertical, domed deaeration section mounted on top of a horizontal cylindrical vessel which serves as a deaerated boiler feed water storage tank.

GENERATOR An electrical generator is a machine

which converts mechanical energy into electrical energy through electro mechanical energy conversion.

The generator is driven by directly coupled steam turbine at a speed of 3000 rpm.

The electricity then goes to a “transformer” where the voltage is increased to 4,00,000 volts before sending it to the “Grid” for distribution via cables.

Mechanical energy

Electrical Energy

ASH HANDLING PLANT The percentage of ash in coal is 5% in good quality coal & about 40% in poor quality coal. Power plants generally use poor quality of coal , thus amount of ash produced by it is quite large.A modern 1000MW plant produces about 4800 tons of ash daily. The stations use some conveyor arrangement to carry ash to dump sites.

COOLING TOWER

The condensate (water) formed in the condenser after condensation is initially at high temperature. This hot water is passed to cooling towers.

It is a tower- or building-like structure in which atmospheric air circulates in direct or indirect contact with warmer water and the water is thereby cooled.

SWITCH YARD

Placed where switching operation of power distribution is performed.

Air insulated switch yard of 220KV-400KV are used.

Main Components of Switch Yard:

Circuit breaker

Isolator

Lightening arrester

Bus bar

Current Transformer

Potential Transformer

SWITCH YARD

CIRCUIT BREAKER

These are used for automatic switching during normal or abnormal conditions .

Specification:

Manufacturer ABB Limited

Type of Circuit Breaker SF6

Rated Voltage 245 KV

Rated Current

Under Site Condition of 40 0C

Under Site Condition of 50 0C

4000 A

2000 A

Rated Frequency 50 Hz

ISOLATOR

These are used to disconnect transmission line under no-load condition for safety, isolation and maintenance.

Specification:

Rated current for site conditions 2000 A

Rated Voltage 245 KV

Rated Frequency 50 Hz

Operating time of Isolator Less than 12 sec.

LIGHTENING ARRESTOR

These are used to discharge lightning over voltages and switching over voltages to earth.

Specification:

Manufacturer Crompton Greaves Ltd, Nasik

Model No. ZLA X 25 C

Ref. Standard IEC 99 – 4. 1991

Rated Frequency 50 Hz

Max. Leakage Current 5 mA

BUS BAR

The conductors to which several incoming and outgoing lines are connected.

They are made up of Cu & Al,

The incoming and outgoing cables are provided for metering purpose.

CURRENT TRANSFORMER

These are used to step-down currents for measurement, control &

protection.

Current transformers are used extensively for measuring current

and monitoring the operation of the power grid.

VOLTAGE TRANFORMER

VT measure voltage and this parameter used for protection of system.

For high voltage CVT (capacitive voltage transformer) is used instead of VT and capacitors play divider role.

We can also use these capacitors for PLC system.

CONCLUSION