Efficiency improvement and superiority of steam injection in gas turbines

Abstract An open cycle gas turbine with a heat exchanger and its modifications have been studied. These modifications include the combinations of the gas turbine with a steam injection system and the gas turbine with a closed cycle steam turbine. The steam is generated by a waste heat boiler. It was found that in both cases the efficiency and the net output of the gas turbine increased considerably, of the order of 20–40%. In order to define the superiority regions of the systems studied on various ranges of power output, an economic analysis per unit power has been done. For short duration, intermittent type of operation the steam injection was found superior. Above this mode of operation, the operational modes of electric base and continuous were covered by the gas turbine combined with the steam turbine.