Gas Turbine
1. Air ratio
2. Pressure ration
3. Work Ratio
4. Compressor efficiency
5. Engine efficiency
6. Machine efficiency
7. Combustion efficiency
8. Thermal efficiency
Some of the important terms used to measure performance of a gas turbine are defined as follows:
1. Pressure ratio. It is the ratio of cycle’shighest to its lowest pressure, usually highest pressure-compressor discharges to the lowest-pressure-compressor inlet pressures.
2. Work ratio. It is the ratio of network output to the total work developed in the turbine or turbines.
3. Air ratio. Kg of air entering the compressor inlet per unit of cycle net output, for example, kg/kWh.
4. Compression efficiency It is the ratio of work needed for ideal air compression through a given pressure range to work actually used by the compressor.
5. Engine efficiency. It is the ratio of work actually developed by the turbine expanding hot power gas through a given pressure range to that would be yielded for ideal expansion conditions.
6. Machine efficiency. It is the collective term meaning both engine efficiency and compressor efficiency of turbine and compressor efficiency of turbine and compressor, respectively.
7. Combustion efficiency. It is the ratio of heat actually released by 1 kg of fuel to heat that would be released by complete perfect combustion.
8. Thermal efficiency. It is the percentage of total energy input appearing as net work output of the cycle.
