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为了探究真空下水平管内流动冷凝的传热状况,以水为工质,在3个不同冷凝温度(45、55和65℃),质量流速为5~12 kg/(m~2·s)和蒸汽干度为0~0.9的范围内,对水平管内流动冷凝的传热特性进行了试验研究。着重探讨了质量流速、干度和冷凝温度等参数对管内传热系数的影响,并详细分析了水平管内流动冷凝的传热机理。试验结果表明:管内传热系数随蒸汽干度的减小而降低,且变化幅度较大;蒸汽质量流速和冷凝温度对管内传热系数在低干度区内影响较小,而在高干度区内影响较大。
In order to explore the heat transfer of the flow condensation in the horizontal tube under vacuum, water was used as the working fluid and the mass flow rate was 5 ~ 12 kg / (m ~ 2 · s) at three different condensing temperatures (45, 55 and 65 ℃) The experimental results show that the heat transfer characteristics of the flow condensation in the horizontal tube are studied in the range of 0 ~ 0.9. The influence of mass flow rate, dryness and condensing temperature on the heat transfer coefficient in the tube was mainly discussed. The heat transfer mechanism of the flow condensation in the horizontal tube was analyzed in detail. The experimental results show that the heat transfer coefficient decreases with the decrease of the steam dryness, and the variation range is larger. The steam mass flow rate and the condensing temperature have less influence on the heat transfer coefficient in the pipe in the low dryness zone, Greater impact in the region.