The use of CO2 air-source heat pump for heating feasibility in low temperature was analyzed. A static simulation model for the CO2 heat pump was developed

and component models of the gas cooler

evaporator

compressor and expansion valve were constructed with careful consideration of the heat transfer performances. To validate the simulation model

experiments were carried out with an actual CO2 heat pump system for heating. By comparing the simulated and experimental data

the effects of the inlet water temperature and outside air temperature on the characteristics of the system were discussed. Furthermore

an analysis on the effect of a recuperator on the performance of the system was analyzed. It is shown that when the outside temperature is -20℃

the COPh is 2.25

which indicates that this system works well in low temperature

and the efficiency of system COPh is improved by 5% when recuperator is used.