Exergy analysis for a combined system of steam-injected gas turbine cogeneration and multiple-effect evaporation

Abstract An exergy analysis has been used for a combination of steam-injected gas turbine cogeneration system and forward-feed triple-effect evaporation process, with and without vapour recompression. The fuel utilization efficiency, power—heat ratio and second-law efficiency are examined for evaluation of the thermal system performance. It is shown that the interaction between the combustion irreversibility and the exhaust exergy losses is dominant in governing the system efficiency with various steam injection ratios and feedstock mass flowrates. The compressor and gas turbine losses are shown to have a relatively small influence.