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新能源和低品位能源利用需要高效相变换热器,将微孔膜插入管内(以下简称调控管)可提高近壁区质量含气率,从而显著强化传热.本文进行了R123在水平管内的冷凝传热研究,比较了光管与调控管的冷凝传热特性.研究表明,微孔膜管可显著强化冷凝传热.在实验参数范围内,强化传热因子EF达到1.118~2.124,综合评价因子PEC在0.71~1.66的范围内,大部分实验工况的综合评价因子大于1.当实验段出口为气液混合物时,强化传热因子EF随入口蒸气质量流速Gxin的增大而增大.当实验段出口为过冷液体时,强化传热规律与之相反.通过可视化图像及管内压力和速度分布的讨论,本文分析了微孔膜管冷凝传热强化机理.
New energy and low-grade energy use require efficient phase change heat exchanger, the microporous membrane into the tube (hereinafter referred to as the control tube) can improve the quality of the gas near the wall, which significantly enhanced heat transfer.In this paper, R123 in the horizontal tube The experimental results show that the microporous membrane tube can significantly enhance the condensation heat transfer. Within the experimental parameters, the enhanced heat transfer factor EF reaches 1.118 ~ 2.124, The evaluation factor PEC is in the range of 0.71-1.66, and the comprehensive evaluation factor for most of the experimental conditions is greater than 1. When the experimental section outlet is a gas-liquid mixture, the enhanced heat-transfer factor EF increases with the increase of inlet steam mass flow rate Gxin When the outlet of the experimental section is subcooled liquid, the law of heat transfer enhancement is the opposite. Through the discussion of the visualization of the image and the distribution of pressure and velocity in the pipe, the mechanism of condensation heat transfer enhancement in the microporous film tube is analyzed.