Abstract:

The experimental facility about the test of pressure drop and heat transfer coefficient in pump-assisted heat pipe was built for the study of characteristics during flow condensation heat transfer. The experimental investigation about characteristics during flow condensation heat transfer of R134a in pump-assisted heat pipe at different mass flux and vapor quality was conducted. The experimental results indicated that pressure drop increases with the increasing vapor quality and the mass flux. The experimental results were compared with three different pressure drop models and the conclusion that Muller-Steinhagen-Heck model can better predict the characteristics of pressure drop in the process of flowing condensation is obtained. In addition, the experimental results indicated that heat transfer coefficient increases with the increasing vapor quality and the mass flux and the growth slope of low vapor quality is higher than that of high vapor quality. The experimental results were compared with four different heat transfer models and the conclusion that Chen model can better predict the characteristics of heat transfer in the process of flowing condensation is obtained. The study provides a theoretical reference for the selection of the pump, the design of the heat exchanger, the optimization of the system and the study of two-phase flow condensation.

Key words: pump-assisted heat pipe, pressure drop, heat transfer, flow, condensation, model

摘要：

针对动力型热管内流动凝结传热过程中的特性复杂未知，搭建了动力型热管冷凝特性测试实验台。对不同流量及干度下的R134a管内流动凝结过程中的压降特性和传热特性进行了实验研究，实验结果表明：压降随着管内工质质量流量和气体干度的增加而增加，与文献中3种不同压降模型进行了比较，得出Muller-Steinhagen-Heck模型能更好地预测管内流动凝结过程中的压降特性。传热系数随着管内工质质量流量和气体干度的增加而增加，并且低干度区的增长斜率要明显大于高干度区的增长斜率，与文献中4种不同传热模型进行了比较，得出Chen模型能更好地预测管内流动凝结过程中的传热特性。该研究为泵的选择、换热器的设计、系统的优化以及两相流凝结相变过程的研究提供了理论参考。

关键词: 动力型热管, 压降, 传热, 流动, 凝结, 模型