Enhancing micro gas turbine performance in hot climates through inlet air cooling vapour compression technique

Microturbines (MGTs) are power generation devices showing very interesting performance in terms of low environmental impact, high-grade waste heat and very low maintenance cost. One of the main issues that affect the output of MGTs is their strong sensibility to inlet air temperature. Both in literature and in practical applications, several solutions have been applied to control the inlet air conditions and reduce the sensibility of this kind of machines to ambient conditions. One of the most interesting technology is the refrigerating vapour compression technique. This solution has already been used for medium/large GTs, but there are very limited inlet air cooling applications on MGTs and few experimental data are documented. This paper describes a test bench that has been designed to apply the direct vapour expansion technique to a 100kWe MGT and reports the power and efficiency augmentation of the machine when operating in hot summer days.