【摘要】 对具有蒸气过热的替代制冷剂R-134a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-134a的质量流量变化范围为100(400kg/(m2s)和蒸气过热度为3.8℃和8.4℃的条件下,得到了螺旋管内具有蒸气过热的R-134a对流凝结换热特性的实验数据。实验结果表明,蒸气过热对R-134a在螺旋管内的凝结换热特性具有明显的影响。通过与已有研究结果的比较,简要分析了蒸气过热对R-134a在螺旋管内凝结换热特性的影响机理。更多还原

【Abstract】 Experimental investigation was conducted on condensation heat transfer characteristics of alternative refrigerant R - 134a with vapor superheat in a helical pipe. The average condensation heat transfer coefficients were experimentally determined for R - 134a in a helical pipe with the superheat of inlet vapor ranging from 3.8 ℃ to 8.4℃. The mass flux for R - 134a ranges from 100 to 400 kg/(m2s). The experimental results show that the vapor superheat has significant effect on the condensation heat transfer characteristics of R- 134a in helical pipes. In addition, the mechanism of the effect of vapor superheat on convective condensation heat transfer of R - 134a in helical pipes was briefly analyzed through comparison of the obtained experimental results with the data in the open literature.更多还原