R-134a在三种不同放置方式螺旋管内凝结换热的实验研究

Experimental Investigation of Condensation Heat Transfer of R-134a ina Helical Pipe at Three Different Orientations

对替代制冷剂R - 1 34a在螺旋管内的对流凝结换热特性进行了实验研究。在制冷剂R - 1 34a的质量流量变化范围为 1 0 0～ 4 0 0kg/ (m2 s)和冷却水的平均温度分别为 1 2℃和 2 2℃的条件下 ,实验得到了在三种不同放置方式螺旋管内 (水平 ,垂直和倾斜 )R - 1 34a的对流凝结换热特性数据。实验结果表明 ,螺旋管的不同放置方式对R - 1 34a在螺旋管内的凝结换热特性具有重要的影响。通过与已有研究结果的比较 ,简要分析了螺旋管不同放置方式对R -1

This paper presents experimental investigation on convective condensation heat transfer characteristics of alternative refrigerant R-134a in a helical pipe. The average condensation heat transfer coefficients were experimentally determined for R-134a at three different orientations (i.e., horizontal, vertical, and inclined orientation directions). The mass flux for R-134a ranges from 100 to 400 kg/(m2s) and the average temperatures of the cooling water are 12℃ and 22℃, respectively. The experimental results demonstrate that the different orientations of helical pipes have significant effect on the condensation heat transfer characteristics of R-134a . In addition, the mechanism of the effect of different orientations of helical pipes on convective condensation heat transfer is briefly analyzed by comparing with prevenient results.