Friends, today in this article we will learn about gas power plant, I am going to give information about all these in a very good way. So let’s start.
Layout of gas turbine power plant
The gas turbine power house is shown in the figure. Filter is used to filter the air. After this the air enters the low pressure compressor.
After the air is compressed, it is passed through the internal coolant. After that it is passed through the high pressure compressor. From the high pressure compressor the air enters the heat exchanger and the hot air flows into the combustion chamber. The combustion products expand in the high pressure turbine. After this they flow into the low pressure turbine.
Elements of a normal gas turbine plant-
A normal gas turbine plant is shown in the figure. Compressor, combustion chamber and turbine are its main components. Air is drawn from the atmosphere through a filter by a compressor. The pressure of the air is increased by the compressor. This compressed air passes through the combustion chamber where fuel is introduced.
Combustion at high temperature and pressure produces a gaseous mixture which expands as it passes through the turbine and produces the force required to rotate the turbine rotor. After expanding through the gaseous surface of the turbine at atmospheric pressure, the temperature of the combustion products is about 1000° to 1500° F. The temperature of the gases is exhausted in the range of 900° to 1100° F. Compressor turbines are mounted on the same shaft. The main part of the gas powerhouse is the turbine which works to run the compressor and produce electrical power i.e. some part of the power produced by the gas is used to run the compressor and the remaining part is used for producing electricity.
1.Turbine – The turbine drives the compressor and the load. Gas turbines have some advantages over steam turbines because they work at low pressure. The turbines used are of two types-
(i) Impulse turbine
(ii) Reaction turbine
Generally axial flow type turbines are used. The turbines used have the following properties-
- Light weight
- High efficiency
- Reliability in operation
- Long working life
2.Combustion chamber –The fuel is burnt in the combustion chamber. The process of combustion takes place inside the chamber. Energy is obtained from this process which is later converted into work by the turbine. The combustion chamber should be of high efficiency because the losses in the combustion process affect the thermal efficiency of the gas turbine powerhouse. The pressure losses in the combustion chamber should be very low and suitable volume and length should be available in the combustion chamber for the combustion of fuel.
Initially the temperature generated in the combustion chamber is very high, hence a balanced amount of air is introduced to maintain the combustion process. The second part of the air is used to cool the hot combustion product. Both primary and secondary air are required for combustion. The combustion chamber is shown in the figure. In aircraft engines, a large amount of air is required to maintain the temperature of the combustion chamber at 650°C and the ratio of air and fuel should be 60:1.
- The combustion chamber should have the following properties-
- Low pressure loss
- High combustion efficiency
- Good flame stability
- Low weight
- Reliability
- Low carbon deposit in turbine and combustion chamber
3.Compressor – Various types of compressors are used in gas power plants, such as reciprocating compressor, centrifugal compressor and axial flow compressor etc. Reciprocating compressors are not used due to friction in the sliding components, high weight, low speed and inability to handle excess air. For high output and efficiency of gas turbine power plants, pressure ratio of 10:1 or more is generally taken. If the pressure ratio of the compressor is not more than 4:1, then the centrifugal compressor is very useful. Also, it can operate efficiently on air with a higher mass as compared to the axial flow compressor. Centrifugal compressors are used in airplanes and where minimum pressure ratio and low volume air is required.
What did you learn today:-
Now you must have known what a gas power plant is. You must have got the answer to all these 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.