PROGRESS AT A GLANCE

Introducing a seminar on:

KOTA SUPER THERMAL POWER STATION (1240 MW)

Electricity by definition is electric current or voltage that is used as a power source!

This electric power is generated in a power plant, and then sent out over a power grid to your homes, and ultimately to our power outlets.

Thermal Power Station A generating station which converts heat energy of coal combustion into electrical energy is known as a Steam Power Station. Classification of a plant: Super Thermal Power Station: A power station having capacity above 1000MW, called super Thermal power station. Sub Critical thermal station: the plant operated below the pressure of 212 Kg/cm2 Super Critical thermal station: the plant operated above 212 Kg/cm2 pressure, called super critical thermal station.

Basic principal of a Thermal power station:

A thermal power station having very heavy instrumentation system, the main instrument of a thermal power station are:

Boiler Boiler drum Boiler Furnace Coal handling plant Ash handling plant Economiser Super heater Air preheater Steam turbine Condenser Electrostatic precipitator

Cooling tower Dearator Boiler feed pump Induced draught Forced draught Alternator Stack Transformers

Coal Handling Plant: The coal is transported to the power station byroad and rail and is stored in the coal storage plant. From the coal storage plant, coal is delivered to the coal handling plant where it is pulverized in order to increases its surface exposure. The pulverized coal is fed to the boiler by belt conveyors. The coal is burnt in the boiler and the ash produced after the complete combustion of coal is removed to the ash handling plant.

Air Preheater:An Air preheater increases the temperature of the air supplied for coal burning by deriving heat from flue gases. The air preheater extracts heat from flue gases and increases the temperature of air used for coal combustion. The principal benefits of preheating the air are-increased thermal efficiency . The air pre heater is made up of Buckets, in which 3 layer of buckets are put on each other, in the middle of layer, a motor is held, which is rotate on its own axis, Air pre heater heat up the air given to the boiler.

BoilerBoiler is the main part of a thermal station . The walls of the boiler made up of thousands of tubes called water walls. And the water is flowing through these tubes, boiler is insulated from outside by the insulating material.

BOILER HOUSE COMPONENT:

BOILER TUBES

Boiler Drum

Super heater:A superheater is a device which superheats the steam, it raises the temperature of steam above boiling point of water. This increases the overall efficiency of the steam. A superheater consists of a group of tubes made of special alloy such as chromiummolybdenum. These tubes are heated by the heat of the flue gases during heir journey from the furnace to the chimney.

Cooling arrangement on a power Station:

Force Draught fan Induced Draught System

Steam turbineFor more complex than a windmill, it consists of stationary and rotating blades mounted on a common shaft and arranged in stages.

First Stage/High Pressure Stage : Steam issuing from the nozzle pushes against the blades and causes the shaft to turn. The steam gives up some of its energy in turning the blades and leaves the first stage at lower pressure and temperature. Second stage /Intermediate Pressure Stage: activated by the same steam and gives up some more energy in turning the blades here. Third Stage/Low Pressure stage the same steams enters this stage at a lower temperature and pressure .1/3 of steam energy is given up in the three stages and leaves the third stage as Exhaust Steam .

Economizers:

The purpose of economizer is to heat feed water so as to recover a part of heat, Which would otherwise be lost through flue gases.

ECONOMIZER TUBES

Dearator:A Dearator is a device that is widely used for the removal of air and other dissolved gases from the feed water to steam generating boilers. In particular, dissolved oxygen in boiler feed waters will cause serious

corrosion damage in steam systems by attaching to the walls of metal piping and other metallic equipment and forming oxides.

Condenser: The surface condenser is a shell and tube heat exchanger in which cooling water is circulated through the tubes. The exhaust steam from the low pressure turbine enters the shell where it is cooled and converted to condensate (water) by flowing over the tubes as shown in the adjacent diagram. Such condensers use steam ejectors or rotary motor-driven exhausters for continuous removal of air and gases from the steam side to maintain vacuum.

Turbo Generator :Generator is the main part of thermal power station or any power plant. A generator is a machine which converts mechanical energy into electrical energy. Turbine is Mechanically Coupled with the Steam Turbine.

STACKA flue gas stack is a type of chimney, a vertical pipe, channel or similar structure through which combustion product gases called flue gases are exhausted to the outside air. Flue gases are produced when coal, oil, natural gas, wood or any other fuel is combusted in an industrial furnace, a power plant's steam-generating boiler, or other large combustion device. Flue gas is usually composed of carbon dioxide (CO2) and water vapor as well as nitrogen and excess oxygen remaining from the intake combustion air. It also contains a small percentage of pollutants such as particulate matter, carbon monoxide, nitrogen oxides and sulfur oxides.

Electro Static Precipitator:To remove fly ash from the flue gases electrostatic precipitators are used. They have collection efficiency over 99.5% The efficiency depends on various parameters such as velocity of flow, quantity of gas, resistivity of ash, voltage of fields, temperature etc.

Principle of Operation:The flue gas laden with fly ash is sent through ducts having negatively charged plates which give the particles a negative charge. The particles are then routed past positively charged plates, or grounded plates, which attract the now negatively-charged ash particles. The particles stick to the positive plates until they are collected by periodically rapping.