Schematic Diagram of a Simple Gas Turbine Power Plant
A simple gas turbine power plant working on open cycle is shown in Figure main components of the gas turbine cycle are :
- A compressor mounted on the same shaft or coupled to turbine.
- A combustion chamber called combustor.
- A gas turbine
- Auxiliaries such as fuel pump, lubrication pump, starting motor etc.
The surrounding air drawn from atmosphere (surroundings) is compressed in se compressor where its pressure is raised and it is supplied to combustor. Simultaneously, Se fuel from fuel tank with the help of pump is injected and sprayed into combustor at hip pressure. The fuel is ignited with the help of ignition system. The combustion of fuel with air raises the temperature of hot gases. The air-fuel rangs form 20 : 1 to 100 : 1 depending upon the application.
The hot gases at high pressure and temperature from combustor enters into the pa turbine. The adiabatic expansion of hot gases and develops mechanical power. The hot after expansion from turbine are discharged to the surroundings. The mechanical power is converted into electrical power by the alternator.
Since the system is not self starting a starting motor is provided.
In this system the part of the work developed by the turbine is used to drive the compressor and remainder is supplied to alternator as shaft work.
These plants can also use external combustion chamber where any type of fuel can be burnt. The resultant hot gases are supplied in a heat exchanger to heat the compressed air before supplied to gas turbine.