A transcritical CO2 heat pump-air conditioning system with ejector and integrated mechanical subcooling (EJ-IMS) is proposed for heating and cooling. The energetic and exergetic performance are discussed compared with baseline transcritical CO2 system (BASE), conventional transcritical CO2 with ejector (EJ), and transcritical CO2 system with integrated mechanical subcooling (IMS). The results indicate a maximum coefficient of performance (COP) is achieved for EJ-IMS, which is improved than other studied systems. EJ-IMS can significantly reduce the optimum discharge pressure. The compressor and gas cooler show the highest irreversible loss. EJ-IMS shows the best annual performance factor (APF), and Haikou has the highest APF.
Keywords CO2, integrated mechanical subcooling, ejector, annual heating and cooling, energetic and exergetic analysis