本文对金属泡沫部分填充的水平管内R134a流动沸腾换热进行了实验研究,研究了质量流速、蒸汽干度和操作压力对压降和换热系数的影响,并将实验数据与传统的光管进行了对比。结果发现,与低质量流速的情况相比,由于在不同质量流速下管内流型不同,导致高质量流速下增加干度更能增强换热,并通过壁面温度分布对沸腾换热流型进行预测。
In this work, the boiling flow heat transfer in horizontal metal-foam partially filled tubes is experimentally studied using HFC134a. The effect of mass flow rate, vapor quality, and operation pressure on flow resistance, and two phase heat transfer coefficient are investigated. The two phase flow and heat transfer performance are compared with conventional smooth tube. It is revealed that the boiling heat transfer can be enhanced by increasing vapor quality for high mass flow rates more significantly than in the case of low mass flow rates. The facts are due to different flow patterns occurred inside the metal-foam tubes. The flow pattern can be predicted by monitoring the cross-sectional wall surface temperatures.