Comparison of the combined cycle efficiencies with different heat recovery steam generators

While most attention of combined cycle developers focus on the gas turbine, only a few papers turn into the steam cycle beginning with the heat-recovery steam generator (HRSG). Therefore, in this paper it has been undertaken the problem of optimal utilisation of the flue gas recovery heat within differently organised HRSGs. For selected advanced ABB GT26 gas turbine composed with four different HRGSs combined cycle have been analysed parametrically using own computer code COM-GAS. The maximum efficiency with respect to steam turbine parameters like power, live steam pressure, has been calculated for four HRSGs with different arrangements of heat exchange surfaces.