An Air Source Heat Pump with the Substitute Refrigerants Working under the Condition of Low Temperatures

摘要

The thermodynamic properties of propane and a non-azeotropic mixture refrigerant of HFC32/HFC125, HCFC-22 alternatives, were analyzed. With the alternative refrigerants, firstly, the basic requirements for designing an air source heat pump and its key components were investigated. Then a new idea of heat compensation for an air source heat pump that works at the condition of low temperature (ASHPWCLT) was put forward. Based on what mentioned above, a practical method used for reasonably analyzing designing parameters, and optimally matching and choosing every parts for ASHPWCLT was described. In addition, the controll principle by adjusting the system itself thermodynamic parameters to make the ASHPWCLT higher efficiency when the system works at high environmental temperature is discussed.