There are a plenty of proposals to aim the gas turbine cycle thermal efficiency of 60%, such as “Steam-Cooled H-Tech. Combined Cycle”, “Methanol Conversion Regenerative Gas Turbine”, “Kalina Cycle” etc.*1, *2, *4, *5, *6, *7
This paper discusses the predicted performance behaviors of an assumed aircraft-derivative GT of 60MW, when applying into mixed gas-steam cycles like STIG, ISTIG(Intercooled Steam Injection GT) with reasonable minor modifications from the assumed gas turbine. By making case studies of steam-injected binary cycles according to the established analyses method in Part (1), typical calculation results for getting 60% efficiency are presented. The water-injected at LPC, ISTIG cycle is equivalent or superior to other improvement ideas, offering several features listed below.
1) Unnecessary to have a bottoming cycle, saving a lot of investment for the related equipment
2) Quick and stable response for changing duty load, by injecting metered water and steam without air holding vessels like water-cooled heat exchangers