【摘要】 搭建水平单管管外冷凝传热实验系统，以R134a为工质，进行了二维和三维结构翅片管管外冷凝换热实验。采用热阻分离法获得管外冷凝换热系数，分析了翅片形式和高度对管外换热性能的影响。结果表明，在实验条件下，二维和三维结构翅片管的管外冷凝传热系数达到了同热流密度下光滑管的3.0～4.1倍和4.1～5.2倍。增加三维翅片高度可增大传热面，削弱表面张力的增益效果，因此翅片高度存在一个最佳值，本研究三维翅片的最佳高度为1.04 mm。更多还原

【Abstract】 An experimental device was constructed to evaluate condensation performance of the horizontal tube. The test tubes were two-dimensional and three-dimensional enhanced fin tubes with working fluid of R134a. The thermal resistance separation method was applied to separate the condensation heat transfer coefficient on the outer surface of the tube. The effects of fin shape and fin height on the condensation heat transfer performance of the test tube were analyzed.It was found that the ratios of condensation enhancement were 3.0～4.1 and 4.1～5.2 for the two-dimensional and threedimensional fin tubes at the same heat fluxes, respectively. The increase in the fin height could increase the heat transfer area, but at cost of losing effect of surface tension. Therefore, there was an optimal fin height for improving condensation heat transfer performance. The optimal fin height for the three-dimensional enhanced tube in this paper was 1.04 mm.更多还原