中文摘要：

本文对：R32/R134a（55.5%/44.5%）、R32/R134a（23%/77%）、R32/R1234ze（60.5%/39.5%）和R32/R1234ze（26.5%/73.5%）四种低GWP混合工质在内径2 mm的水平光滑圆管内的冷凝换热特性进行了实验研究和理论分析。设定饱和温度为35℃和40℃,对四种混合工质在不同干度下的冷凝换热系数进行了测试,发现四种混合工质的冷凝换热系数在18 kW·m-2·K-1之间,且冷凝换热系数随饱和温度升高而降低,随质量流量增加而增加;比较了相同工况、不同混合比下的混合工质换热系数,发现混合工质的传热恶化现象随着面积质量流量减小而变得明显。本文将实验得到的冷凝换热系数408个实验数据与8个模型的预测结果进行了比较,发现多数关联式的预测误差较大,仅有Fuji-Nagata关联式的预测值与实验值较为接近。

英文摘要：

In this paper,Condensation of four refrigerant mixtures with low GWP,R32/R134a（55.5%/44.5%）,R32/R134a（23%/77%）,R32/R1234ze（60.5%/39.5%） and R32/R1234ze（26.5%/73.5%）,in a horizontal smooth round tube with a 2 mm inner diameters was investigated experimentally and theoretically.The condensation temperature was set as 35℃ and 40℃.Heat transfer coefficients（HTCs） of four refrigerant mixtures in different quality have been tested.In conclusion,HTCs ranged from 18 kW·m-2·K-1.the HTCs of condensation improved with the decrease of saturation temperature and the increase of mass flux.In the same operating condition,the HTCs of refrigerant mixtures with different mixing ratio has been compared.We found that the heat transfer deterioration phenomenon of refrigerant mixtures become obvious with the decrease of area mass flow.408 experimental datas of HTCs were compared with theoretical results predicted by the eight modes.It showed that the prediction error of most correlations is bigger.Only predicted values by Fuji-Nagata correlation were in better agreement with experimental values.