In an automobile engine, output power varies with change in ambient conditions such as altitude and location. In order to compensate this variation, superchargers are used.
Superchargers are devices that raise the pressure of air or air-fuel mixture that is to be supplied to the engine, above atmospheric pressure. By doing so, they compensate the variation in output power of the engine. Several types of superchargers are available for IC engines.
What is a turbocharger?
A turbocharger is a special type of supercharger in which a gas turbine is used to raise the pressure of air or air-fuel mixture, that is to be supplied to the engine. Turbochargers are powered by the kinetic energy of exhaust gases from the engine.
Working of Turbocharger:
A turbocharger contains a gas turbine coupled to a compressor. Both the turbine and the compressor are keyed to the same shaft. Whenever the turbine rotates, the compressor is operated.
Exhaust gases from the engine is allowed to fall on the gas turbine. The turbine rotates. This makes the compressor work.
The compressor compresses air (in case of petrol engines) or air-fuel mixture (in case of diesel engines) that is to be fed to the engine. This raises the pressure of air or air-fuel mixture above atmospheric pressure. Such an increase in pressure fuels the output power of the engine. It facilitates smooth operation of the engine in different ambient conditions.
See the schematic diagram above for better understanding
Benefits of using a turbocharger:
- Turbocharger increases the volumetric efficiency of the engine.
- It increases the output power produced.
- It reduces the intake of fuel or air-fuel mixture.
- It allows the engine to work smoothly in various ambient conditions.
- The kinetic energy of exhaust gases is fed back to the engine and used beneficially.