本文采用计算和实验相结合的方法研究了制冷工质在水平光管和强化管管外的冷凝传热。模拟采用了VOF多相模型和Lee相变模型得出凝结液的瞬态传热系数,分别讨论了水平光管和强化管外液膜的瞬时膜流特性。 与实验数据和Nu解析解吻合良好,误差在10%以内。分析了液膜周期性滴落特性,计算了不同工况下光管和强化管的冷凝液膜厚度和冷凝传热系数,得出强化管管外凝结传热系数大约是光管的6倍左右。对不同制冷剂在相同工况下进行了比较,结合冷凝液膜的分布和制冷剂物性参数可得,R410A的管外冷凝系数最高,R1234yf的管外冷凝系数最低。

This study adopts a combined approach of calculation and experimentation to investigate the condensation heat transfer of refrigerants outside smooth and enhanced horizontal tubes. The simulation utilized the VOF model and Lee condensation model to obtain the condensing heat transfer coefficient. Instantaneous film flow characteristics of condensation outside horizontal the smooth and enhanced tubes were discussed respectively. The results agree well with the experimental data and analytical solution of Nusselt, the error is within 10%. The periodic dripping characteristics of the liquid film were analyzed. The condensate film thickness and condensation heat transfer coefficient are calculated for both smooth and enhanced tubes under different operating conditions, and it is found that the condensation heat transfer coefficient outside the enhanced tube is approximately six times that of the smooth tube. A comparison was made among different refrigerants under the same operating conditions. Combining the distribution of the condensate film and the thermophysical properties of the refrigerants, it was determined that R410A has the highest condensation coefficient on outside of tubes, while R1234yf has the lowest condensation coefficient.

TK124

上海市动力工程多相流动与传热重点实验室研究项目(2019KJFZ201)