THermodynamic Performance Analysis Of Supercritical Co2 Brayton Cycle

Abstract

The supercritical CO2 is used as working fluid for power system cycle. This paper presents thermodynamic performance analysis results on supercritical CO2 Brayton cycle. Based on the assumptions of the relevant initial parameters, the mathematical models of compressor, turbine, recuperator and heater are constructed, and the thermal efficiency of regenerative Brayton cycle and recompression Brayton cycle are calculated and analyzed. The results reveal that the efficiency of the recompression cycle is higher than that of the simple regenerative cycle. The effects of inlet temperature, inlet pressure of the main compressor and inlet temperature, inlet pressure of the turbine on the thermodynamic performance of the recompression cycle are studied, and the influencing mechanism is explained. The results show that the cycle efficiency decreases with the increase of the inlet temperature of the main compressor. There exists an optimum inlet pressure in the main compressor to maximize the cycle efficiency. The cycle efficiency of the system increases with the increase of the inlet temperature and pressure of the turbine. When the inlet temperature of the turbine exceeds 600, the thermal efficiency of the cycle can reach more than 50%.