Energy, Exergy And Exergoeconomic Analysis Of Two For Waste Heat Recovery Of Gas Turbine

Nowadays, waste heat recovery for gas turbines has attracted more and more attention and supercritical CO2 (SCO2) cycles have been proved efficient in this scenario. The current S-CO2 power cycles are mainly combined with other bottom cycles, which will increase system cost. To avoid this shortcoming, two novel S-CO2 cycle layouts are proposed to further develop energy systems with better economic performance. Different modifications have been made to the cycles to decrease the exhaust temperature and recover the heat adequately. Firstly, energy, exergy and exergoeconomic of the two systems are analyzed to obtain deeper comprehension of the cycles for waste heat utilization. Then, the influences of five decision parameters including inlet and outlet temperature difference of exhaust gas, temperature difference in the recuperators, pressure ratio and compressor inlet pressure on thermal efficiency, exergy efficiency and cost of per kilowatt hour are obtained by parametric studies. Based on comparison with traditional combined cycles proposed in literatures, the proposed S-CO2 cycles show more competitive economic performances (3.63 cent/kWh and 3.56 cent/kWh for two systems, respectively) without significant thermodynamic performance loss. Therefore, the proposed systems present new attempts for utilization of waste heat from gas turbines with lower cost and provide reference for the design of similar cycles.