Optimum Power Boosting of Gas Turbine Cycles With Refrigerated Inlet Air and Compressor Intercooling
With or without turbine blade cooling, gas turbine cycles have consistently higher turbine inlet temperatures than steam turbine cycles. But this advantage is more than offset by the excessive compressor work induced by warm inlet temperatures, particularly during operation on hot summer days. Instead of seeking still higher turbine inlet temperatures by means of sophisticated blade cooling technology and high temperature-resistant blade materials, it is proposed to greatly increase the cycle net work and also improve thermal efficiency by decreasing the compressor work. This is obtained by using refrigerated inlet air and compressor intercooling to an extent which optimizes the refrigerated air inlet temperature and consequently the gas turbine compression ratio with respect to maximum specific net power. The cost effectiveness of this conceptual cycle, which also includes regeneration, has not been examined in this paper as it requires unusually high pressure ratio gas turbines and compressors, as well as high volumetric air flow rate and low temperature refrigeration equipment for which reliable cost data is not easily available.