中文摘要：

CO2因为环保及独特的热力学优势，一直是制冷空调领域的研究热点，然而由于其工作压力较高，用于家用热泵热水器的全封闭式CO2压缩机开发较困难。为了验证CO：在热泵热水器上应用的优势以及研究其系统的运行规律，以国产全封闭式CO2压缩机为基础，设计并搭建了空气源CO2热泵热水器测试系统，在进水温度15—50℃，出水温度65-90℃范围内，测试了不同进、出水温度、不同蒸发温度以及不同排气压力条件下，热泵系统的制热量、COP以及排气温度等关键特征，发现CO2能够稳定提供90℃以上热水，在高温制热上优势明显。同时，即使在蒸发温度为-20℃，系统仍然能够平稳运行，表现出较好的低温运行优势。

英文摘要：

CO2 is one of the research focuses in the refrigeration field due to its environmental protection and unique thermodynamic properties. The hermetical C02 compressor for house-hold appliance is a big challenge because of its high pressure. In order to verify the superiority of CO2 application in the heat pump water heater and test the operation law of the system, a new C02 heat pump water heater prototype with hermetical compressor developed in China was tested. Keeping the inlet water 15-50 ℃ and the outlet hot water 65-90 ℃ ,the key characters such as the heating capacity, COP and the exhaust temperature with different evaporating temperature, inlet and outlet water temperature, and exhaust pressure were measured. The results show that the CO2 heat pump water heater can steadily provide hot water above 90 ℃, having obvious advantages in heating at high temperature. The system can still run smoothly when the evaporation temperature is -20 ℃, showing better advantages in heating at low temperature.