TWO-STAGE DRYING OF CO2 TRANSCRITICAL CYCLE HEAT PUMP
Work partially supported by the project No.50506019 of the Nature Science Fund of China.
Heat pump with the natural refrigerant CO2 is receiving more attention due to its good properties for environment and CFC substitution problem. In this study, the two-stage drying of CO2 transctitical cycle heat pump is discussed. The drying system is designed based on the thermophysical properties and characteristics of CO2. The single compression cycle single stage drying CO2 heat pump dryer, the two-stage drying CO2 heat pump dryers and electric drying system are compared. The analysis indicates that the efficiency of the two-stage drying CO2 system can be higher than that of the single drying CO2 system. The energy utilization rate of CO2 heat pump dryer was higher than an electric dryer.
