2.4. Simple Gas Turbine Plant
A gas turbine plant may be defined as “a plant in which the principal prime-mover is of the turbine type and the working medium is permanent gas”.
Refer Fig. 7. A simple gas turbine plant consists of the following:
2.A compressor mounted on the same shaft or coupled to the turbine.
Fig. 7. Arrangement of a simple gas turbine plant.
4. Auxiliaries such as starting device, auxiliary lubrication pump, fuel system, oil system and the duct system etc.
A modified plant may have in addition to above an intercooler, regenerator, a reheater etc.
The working fluid is compressed in a compressor which is generally rotary, multistage type. Heat energy is added to the compressed fluid in the combustion chamber. This high energy fluid, at high temperature and pressure, then expands in the turbine unit thereby generating, slower. Part of the power generated is consumed in driving the generating compressor and accessories and the rest is utilised in electrical energy. The gas turbines work on open cycle, semi-closed cycle or closed cycle. In order to improve efficiency, compression and expansion of working fluid is carried out in multistages.