EXPERIMENTAL AND THEORETICAL STUDY OF MICRO GASTURBINE PERFORMANCE AUGMENTATION

The present study investigates two techniques of gas turbine performance augmentation which arecooling intake air and applying of intercooler between two compressors. Power augmentation from a 4 kW-micro gas turbine test unit using evaporative and coil cooling systems has been experimentally investigated. The parametric study examines the effect of ambient air conditions (temperature, humidity and pressure) on evaporative and coil cooling gas turbine cycles. The experimental results reveal that the performance of gas turbine cycles is successfully improved by decreasing the temperature of inlet air. The cooling coil cycle is capable of enhancing the efficiency of the studied gas turbine unit by 2% at low ambient temperature and 6% at high ambient temperature, whereas the evaporative cycle merely increases the efficiency by about 1%. Reducing the temperature from ambient condition to ISO standard condition could boost gas turbine efficiency by 3%. The effect of ambient relative humidity indicates that coil cooling outperforms evaporative cooling by 3%. In general, the efficiency of turbine cycles deteriorates at a relative humidity level greater than 20%. Another method of gas turbine power augmentation, which is applying intercooler between two compressors, is also investigated theoretically. It is found that this method can enhance turbine performance especially at a high expansion ratio.