Energy and exergy analyses of a combined cycle power plant with inlet fuel heating

Abstract

By using exhaust gas as heating source, a combined cycle power plant with inlet fuel heating is investigated experimentally. Energy analysis and exergy analysis are carried out under different power load and ambient temperature. The results reveal that the thermal efficiency of the power plant system increases as power load increases. The thermal efficiency and power output at 5?C are 54.15% and 412 MW, respectively; while when the ambient temperature is 35?C, the thermal efficiency and power output are 52.3% and 330 MW, respectively. Under the same conditions, the combustion chamber has the highest irreversibility rate, while the air compressor has the lowest. The irreversibility rate of the power plant system increases in line with power load. The second-law efficiency increases from 37.08% to 50.12% when the power load changes from 30% to 100%.