A flow condensation experimental study with binary mixture in a horizontal rectangle 1 mm-channel was carried out. The flow patterns, heat transfer characteristics and frictional pressure gradients were analyzed based on the parametric study. Pure refrigerants R134a, R245fa and their three mixtures R134a/R245fa (70/30, 30/70 and 10/90 by wt%) were selected in this study. The impacts of mass flux, saturation temperature and wall subcooled temperature on the flow condensation were discussed. Flow pattern transition characteristic was studied and an annular-intermittent flow transition criterion considering the composition and temperature glide was proposed. The heat transfer deterioration was discussed and the mass transfer resistance was characterized by some physics parameters and working conditions. The frictional pressure gradient of zeotropic mixture was weakened because of the temperature glide. New prediction methods of heat transfer coefficient and frictional pressure gradient for R134a/R245fa were developed, and both the prediction correlations showed satisfactory accuracy.

在水平矩形1 mm通道中使用二元混合物进行流动冷凝实验研究。在参数研究的基础上，分析了流场，传热特性和摩擦压力梯度。本研究选择了纯制冷剂R134a，R245fa及其三种混合物R134a / R245fa（按重量百分比计分别为70 / 30、30 / 70和10/90）。讨论了质量通量，饱和温度和壁过冷温度对流动冷凝的影响。研究了流型转换特性，提出了考虑成分和温度滑移的环形间歇式流转换准则。讨论了传热恶化，并通过一些物理参数和工作条件表征了传质阻力。由于温度滑移，共沸混合物的摩擦压力梯度变弱。建立了R134a / R245fa传热系数和摩擦压力梯度的新预测方法，两者的预测相关性均显示出令人满意的精度。