Open cycle gas turbine
A gas turbine plant consist of compressor ,combustion chamber,gas turbine and alternator. the compressor take atmospheric air, compress it and the presser is pressed air to the combustion chamber. Flue is injected in to the combustion chamber and burnt in stream of air supplied by the compressor . the combustion raises the premature of air and increase it volume under constant presser. The hot pressurized gas expands in the turbine, produces mechanical power and turns the rotor of the turbine both the compressor and alternator are coupled to the turbine shaft . Due to the high temperature of the products of combustion,
The turbine output exceeds the input to the compressor there fore turbine drives the compressor and surplus power drives the alternator. The product of combustion after expansion threw the turbine are finally exhausted to the atmosphere such plant are none as open cycle gas turbine plant . Some times two turbines are used . A high pressure turbine drives the compressor and low pressure turbine drives the alternator. This arrangement has the advantage that the speed of the turbine can be kept at power generation start synchronous speed while the speed of the turbine driving the compressor can be varied depending on the required output.
Closed cycle Gas turbine
Close cycle Gas turbine plant have following advantage
1. A working medium having more disierable property than air can be used. These are hydrogen,organ,helium ext.
2. The risk of corrosion of turbine blat is absent
3. The working medium is at high internal presser. this results in economy in die mention of turbine ext.
4. In an open cycle plant the incoming air gas to be filtered
5. The rate of heat transmissions better In an open open cycle plant the fuel is mixed with air in the combustion chamber and the heat rejection. process occurs in the atmosphere as the turbine exhaust is discharge into the atmosphere in a close cycle plant . The fuel is not mixed with the woe king medium which can be air or any other gas.