Friends, today in this article we will learn about the working of a thermal power plant. I am going to give information about all this in a very good way. So let’s start.
Working of thermal power station-
At thermal power stations, steam is generated at high temperature and pressure in boilers from the combustion heat of coal or fuel. This steam runs steam turbines or steam engines which generate electrical power by running coupled generators. The efficiency of these power plants is 15 to 20%.
Coal is usually collected in bins in open space. Coal storage is near railway lines, motor traffic or water traffic. There are coal crushers to grind coal from where the crushed coal is dropped into the boiler hoppers with the help of belt conveyors.
After burning of coal in the boiler furnace, the ash collects in the ash pit behind the boiler from where it is taken to the ash storage with the help of a conveyor and collected.
For complete burning of coal in the furnace, air is supplied to the boiler furnace from the air preheater by force draught fans. The hot fuel gases coming out of the furnace pass through the superheater, economiser and air preheater and are discharged through the chimney by induced draught fans.
After superheating the steam produced in the boiler in the superheater, it is sent to the steam turbine. An alternator is coupled to this steam turbine which runs when the steam turbine runs and generates electrical power. An exciter is coupled to the alternator to provide the magnetic field.
The steam coming out of the turbine is discharged into the condenser at very low pressure. Cold water is circulated in the condenser to cool the steam. The water formed in the condenser is drawn by the condensate extraction pump. This water is sent back to the boiler via the low pressure heater, high pressure heater and economizer.
All its main equipment and functions are as follows:
(a) Pulverizing Plant – This equipment pulverizes coal. It has many advantages. With this, the rate of fuel combustion can be controlled and the rate of combustion can be changed when there is a change in the load. The boiler can be started quickly even in cold weather.
(b) Draft System – Adequate supply of air is required for combustion in the boiler. The circulation of air occurs due to the difference in pressure, it is called draft. Thus draft is the difference in pressure between two points. These two points are the atmosphere and the boiler. Draft systems are of two types – natural and mechanical draft.
(c) Boiler – Boiler is a closed vessel in which water is converted into steam under pressure. Boiler is built with the purpose of absorbing excess heat so that it can absorb more heat produced by combustion.
(d) Superheater – Superheater is the heat which contains more heat than the balanced heat while the pressure remains the same. It is heated more than the temperature according to its pressure. This extra heat provides more energy to the turbine. The function of superheater is to remove moisture from the balanced steam and increase the temperature of this steam. The heat of combustion gases is used in superheater.
(e) Steam Turbine – Steam turbine converts the thermal energy of steam into mechanical energy and drives the generator. Steam turbine uses the principle that it keeps the speed of steam high.
(f) Ash Handling Plant – Coal contains most of the ash. The percentage of ash in good grade coal is about 5% and in low grade coal it is about 40%. A modern 200 MW plant produces 5000 tons of ash daily.
(g) Condenser – The function of the condenser is to cool the gases coming out of the turbine, so it helps in balancing the low pressure at the exhaust. It increases the capacity of the plant. The exhaust heat is cooled and given to the boiler as feed water.
(h) Economiser – The gases coming out of the boiler have a lot of heat. The economiser emits some part of this heat and it is used to heat the feed water. The use of economiser saves the cost of coal and it has more boiler capacity but for this separate capital has to be invested and the cost of maintenance increases.
What did you learn today:-
Now you must have known the working of a thermal power plant. You must have got the answer to all the questions well.
I hope you liked the information given by me. If you have any question/suggestion in your mind, then you can tell me by commenting below, I will definitely answer your comment. If you liked this post, then you can also share it with your friends and relatives.