为研究R410A与R134a在水平光管内的冷凝换热特性，在管内冷凝换热试验台上进行冷凝试验，分析质量流量、冷凝温度、测试水雷诺数Re、管径和制冷剂物性对换热系数和压降的影响。研究表明：换热系数、压降均随着质量流量的增加而变大，随冷凝温度的升高而减小，换热系数随测试水雷诺数Re的增加而减小，而测试水雷诺数Re对压降的影响相对较小；尽管R410A的换热系数随管径的减小而增大，而管径对R134a换热系数的影响并不显著，R134a与R410A的压降均随管径的减小而增大；单位压降换热系数随质量流量的增加而减小；Cavallini et al.关联式可较好预测R410A与R134a在光管内换热系数，而Shah关联式只能用于预测R134a的换热系数。

Condensation experiment was operated on the in-tube condensation heat transfer test rig,to study the condensation heat transfer characteristics of R410A and R134a inside the horizontal smooth tube.The heat transfer coefficient and pressure drop were selected as evaluation indexes,and the mass flux,condensation temperature,water-testing Re ,diameter,and refrigerant properties were chosen as the influencing factors.The experimental result showed that: the heat transfer coefficient and pressure drop increase with increasing mass flux and decreasing condensation temperature,and the heat transfer coefficient decreases with water-testing Re ,while the influence of water-testing Re on the pressure drop is relatively small.Although the heat transfer coefficient of R410A increases with decreasing diameter,the influence of diameter on heat transfer coefficient of R134a is very small,and the pressure drops of R134 and R410A increase with decreasing diameter.The heat transfer coefficient under unit pressure drop was proposed to evaluate the integrated performance of test tube,and the heat transfer coefficient under unit pressure drop decreases with increasing mass flux.Finally,the experimental data was compared with the predicted value of classical correlations.The Cavallini et al correlation can better predict the experimental data of R410A and R134a,while the Shah correlation can only be used to predict the heat transfer coefficient of R134a.

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