Abstract The objective of this research is to model steam injection in the gas turbine with Air Bottoming Cycle (ABC). Based on an exergy analysis, a computer program has been developed to investigate improving the performance of an ABC cycle by calculating the irreversibility in the corresponding devices of the system. In this study, we suggest two new cycles where an air bottoming cycle along with the steam injection are used. These cycles are: the Evaporating Gas turbine with Air Bottoming Cycle (EGT-ABC), and Steam Injection Gas turbine with Air Bottoming Cycle (STIG-ABC). The results of the model show that in these cycles, more energy recovery and higher air inlet mass flow rate translate into an increase of the efficiency and output turbine work. The EGT-ABC was found to have a lower irreversibility and higher output work when compared to the STIG-ABC. This is due to the fact that more heat recovery in the regenerator in the EGT-ABC cycle results in a lower exhaust temperature. The extensive modeling performed in this study reveals that, at the same up-cycle pressure ratio and turbine inlet temperature (TIT), a higher overall efficiency can be achieved for the EGT-ABC cycle.

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