Limiting the Effect of Ambient Temperature on Micro Gas Turbines (MGTs) Performance Through Inlet Air Cooling (IAC) Techniques: An Experimental Comparison between Fogging and Direct Expansion

This paper describes a test bench that has been designed to evaluate the effect of inlet air cooling (IAC) techniques on the improvement of the performance of a 100 kWe micro gas turbine (MGT). In particular, two inlet air cooling techniques were tested: the fogging and the direct expansion. The results of the experimental analysis show that with the fogging technology the electric power augmentation ranges between 4% and 11% referred to the machine's ISO condition output depending on the initial conditions of the ambient air humidity. During the tests with direct expansion technology, a net electric power augmentation up to 8% referred to the machine's ISO condition output was registered; also the net electric efficiency gain showed a peak of 1.5%.