Abstract

Exergy is described as a measure for identifying and explaining the benefits of technologies. Therefore in this research the performance of water and steam injection in the gas turbine with air bottoming cycle (ABC) is evaluated based on an exergy analysis and thermodynamic laws. In this study, we suggest four efficient cycles incorporated to theABC that three of them are novel. The cycles are: water injection-1 (WI-ABC-1), water injection-2 (WI-ABC-2), steam injection-1 (SI-ABC-1) and steam injection-2 (SI-ABC-2). The analysis results show the cycles have more thermal efficiency, net output power and exergy recovery respectively. The SI-ABC-1 and SI-ABC-2 were found to have minimum exergy loss and maximum output power in the same operating conditions. The lowerexergy loss is caused due to more heat recovery in the regenerator in the SI-ABC cycles, and more inlet mass to bottoming turbine results in a higher output power. Also, this research investigates the effects variations of pressure ratio, ambient temperature and turbine inlet temperature on outputs.

Key words: Air bottoming cycle (ABC) gas turbine, water injection, steam injection, exergy analysis, exergy recovery.