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摘 要: 对一台空气源热泵翅片管蒸发器表面结霜特性进行了实验研究，分析了室外环境温度和相对湿度对霜层形态和密度的影响。实验结果表明，室外环境温度的降低或相对湿度的增大促使换热器表面霜层在其生长过程中形成针状霜晶，乃至形成绒状霜层；而对高温、高湿度工况，霜层表面出现了首先形成凝结水滴的现象，使得霜层密度大大增加。霜层厚度的分阶段增长特性对霜层平均密度会产生很大影响，在霜层减速生长段，霜层平均密度随结霜时间呈现出增长趋势，而在霜层加速增长段，霜层平均密度随结霜时间迅速减小，且当地霜层密度远远低于霜层平均密度。对不同环境参数条件下的实验数据的比较表明，平均密度随环境温度的升高及相对湿度的减小而增大，且相对湿度的影响在低湿度工况下更强烈。 关键词 ：空气源热泵；结霜；霜层密度；霜层生长特性 Effects of Environment Conditions to Morphology and Density of Frost Layer on Evaporator Surface of Air Source Heat Pump Wang Shanyun Guo Xianmin Cheng Yiguang Wang Weihua Tianjin University of Commerce, Tianjin Key Laboratory of Refrigeration Technology, 300134, Tianjin Abstract: The frosting characteristics of the fin-tube evaporator of an air source heat pump (ASHP) were investigated experimentally. The effects of the outdoor air temperature and humidity on the frost morphology and density of the frost layer were analyzed. The experimental results indicate that the decrease in the outdoor air temperature or the increase in the relative humidity results in the formation of the acerose-shaped ice crystals, even of the fluffy frost layer, on the evaporator surface of the ASHP. Under the conditions of the high air temperature and humidity, the average frost density is raised significantly due to the appearance of the water droplet on the frost layer surface. The three stages growth manner of the frost layer thickness has a great influence on the average frost density. In the second stage, the average frost density increases with the frosting time. In the third stage, the average frost density decreases rapidly with the frosting time and the local frost density is much lower than the average density of the frost layer. The compares among the experimental data of the different environment parameters show that the average density increases with the increase in the ambient temperature and the decrease in the relative humidity and the impact of the relative humidity in the low humidity conditions is stronger. Keywords: Air source heat pump; Frost; Frost density; Frosting characteristics