An experimental study of condensation heat transfer using R410A in a multiport extruded tube.

In this study, the condensation heat transfer of R410A flowing inside a flat aluminum multi-port minichannels is investigated. The multi-port minichannels test tubes have 7 channels with a 1.16mm hydraulic diameter are designed as a counterflow tube in tube exchanger. The experiment is performed with mass fluxes of refrigerant between 50-500 kg/m2s, with 3-15kW/m2 of heat fluxes, and saturation temperature of 48°C. The average heat transfer coefficient increased with the increase of vapor quality, mass flux, and heat flux. The experimental data are compared with existing correlations, and the data of high mass flux agree with the existing correlation, while those of low mass flux show different trends. The correlation is modified a good agreement with the experimental data of this study.

本研究针对R410A制冷剂在扁平铝制多端口微通道（flat aluminum multi-port minichannels）内流动时的冷凝换热特性展开实验研究。本次实验所用的多端口微通道测试管包含7条通道，水力直径为1.16mm，采用逆流套管式换热器结构设计。实验工况参数设置如下：制冷剂质量流量密度范围为50~500 kg/m²·s，热流密度范围为3~15 kW/m²，饱和温度设定为48℃。研究发现，平均换热系数随蒸气干度、质量流量密度及热流密度的升高而增大。将本次实验数据与现有传热关联式进行对比后可知，高质量流量密度下的实验数据与现有关联式吻合度较好，而低质量流量密度下的实验数据则呈现出不同的变化趋势。通过对原有关联式进行修正，修正后的关联式与本研究的实验数据实现了良好的吻合。