热泵型空调机组室外机制冷剂侧换热与流动

针对热泵型空调机组室外机换热面积通常大于室内机换热面积的特点，对室外机换热面积变化对其换热量及机组性能系数的影响进行了研究。分别在制冷和制热工况下测试了室外机沿制冷剂管路管壁温度。在此基础上，建立了室外机传热和制冷剂流动计算模型，并对以R22为工质的一机组进行了实例计算。结果表明：制冷剂在冷凝器和蒸发器内的相变过程均为非定温过程，但温度变化较小，且供热时作为蒸发器的室外机的压降大于制冷时作为冷凝器的室外机的压降。当室外机换热面积远大于室内机换热面积时，室外机换热量和机组性能系数均随换热面积的减小而减小，但减小的幅度远较换热面积减少的比例小得多。且在制热工况下的影响远小于制冷工况。

THE INVESTIGATION OF HEAT TRANSFER AND REFRIGERANT FLUID PROCESS IN HEAT PUMP AIR CONDITIONER

Area of heat pump air conditioner is larger obviously than that of inner unit. The effect of change of area of outer unit upon its heat exchange quantum and COP of air conditioner were investigated. Temperatures of tube wall of outer unit were measured both in refrigerating condition and heating condition. A model used to calculate heat transfer coefficient and refrigerant pressure drop of outer unit based on the experiment was proposed. A case study of heat pump air conditioner used R22 as refrigerant was carried out. The results showed that the temperature of phase change process of R22 in condenser and in evaporator isn’t constant, but the temperature glide is less than 0.5℃, and the temperature glide in heating condition is greater than that in refrigerating condition. Heat exchange quantum of outer unit and COP of air conditioner decrease as area of outer unit decreases, but the extent decrease is less than area decrease, and the effect on heat exchange quantum of outer unit and COP of air conditioner in heating condition is less than that in refrigerating condition.