For generating the electrical energy from the alternator, it is necessary to rotate alternator by means of any source of mechanical energy. This mechanical energy produced from different sources. If the mechanical energy generates with the diesel engine, the power station known as the diesel power plant.
Generally, Thermal Power Plants and Hydro Power Plants used to produce main power. But, for Thermal Power Plants need sufficient amount of coal and water. In case of the Hydro Power Plants, it needs big dams and continuous source of water at height.
Diesel power plant used as a stand by source of electrical energy. It is commonly used in the complex, hospitals, hotels, and offices during the main source of electrical energy is not available.
Components of Diesel Power Plant:
1) Engine: A diesel engine is used to produce the required power. The engine connected with the generator by the common shaft.
2) Fuel System: It consists of the storage tank, fuel transfer pump, fuel pump, strainer, and heater. According to the load on the plant, the fuel supplied to the engines. The strainer used to remove solid particles when fuel is passing from the main tank to smaller dry tank.
3) Cooling system: It consists of the cooling towers, water source, spray ponds, water circulating pumps and water filtration plant. The cooling system used to keep the temperature of the cylinder in a safe range.
4) Air-filter: For combustion of the fuel, the air is necessary. The air-filter used to remove the dust from the air which is taken by the engine.
5) Supercharger: It used to increase the pressure of the supplied to the engine to increase the power of the engine.
6) Exhaust system: It consists of the silencer and connecting ducts. The gas produced during combustion of the fuel. This gas removed by the exhaust system.
7) Starting system: It includes an air compressor and starting air tank. The starting system used to start the engine. In a small diesel generator, the initial rotation of the shaft provides by handles. For large diesel engine, compressed air used for starting.
Working Principle of Diesel Power Station:
The working principle of Diesel Power Plant is very simple. A cylinder filled with compressed air with the compensation ratio is 12 to 20. By burning the diesel, this air becomes high pressure and high temperature. This air used to rotate the rotor of the generator. The diesel engine connected with the same shaft of the generator. Hence, the diesel engine works as a prime mover. This is how, in diesel power station, the chemical energy (fuel energy) converted into mechanical energy and mechanical energy converted into electrical energy.
Advantages of Diesel Power Plant:
- It requires a very small space.
- It has quick stating facility. The diesel generator can start in very few seconds. It can also stop as when required stopping. Because of this facility, small diesel power plants prefer as a backup power source.
- The initial cost is less than other types of power station.
- It requires a small quantity of water for a large power plant. For small generating unit, it not required water.
- Cooling is easy.
- The design of the plant is easy.
- Location of the plant is very near to the load.
- There are not any difficulties with varying load.
- Thermal efficiency is higher than the other plants.
- Fuel handling is easier.
- I require fewer labors.
Disadvantages of Diesel Power Plant:
- The cost of diesel is high as well as increases day by day. This is the main reason for which the diesel plant is not popular for the continuous or main power source.
- Cost of lubricants is high.
- Plant capacity is limited.
- The maintenance cost is high.
- The noise produced by the diesel engine.
- In an overload condition, the plant does not work satisfactorily for a longer period of time.