摘要：
基于双边界层理论,建立含CO2的蒸汽在竖直平板表面凝结换热模型.CO2的存在极大恶化了凝结换热性能.在CO2浓度一定时,随着过冷度的增加,热流密度逐渐增大,凝结换热系数逐渐减小,界面温度近乎线性降低;随着CO2浓度的增大,凝结换热系数迅速降低,界面温度逐渐增大.CO2的存在使得凝结液膜表面形成一层气膜,随过冷度的增大,液膜厚度逐渐增加,气膜厚度逐渐减小,但气膜厚度要比液膜厚度大一个数量级;随着CO2浓度的增大,液膜厚度与气膜厚度均在减小,但气膜热阻与液膜热阻的比值逐渐增大,并且在高浓度CO2情况下,气膜热阻成为主导热阻.%Based on the double boundary layer model,this work established a laminar condensation heat transfer model of steam with CO2 on a vertical plate.The condensation heat transfer performance is deteriorated greatly due to the presence of CO2.At a certain concentration of CO2,with the increase of surface sub-cooling,the heat flux increases,the heat transfer coefficient decreases,and the interface temperature decreases almost linearly.With the increase of CO2 concentration,the heat transfer coefficient decreases rapidly while the interface temperature increases gradually.In addition,the presence of CO2 results in the formation of a layer of gas film outside the liquid film.With the increase of surface sub-cooling,the thickness of liquid film increases and the thickness of gas film decreases.Hoowever the thickness of the gas film is one order of magnitude larger than that of the liquid film.With the increase of CO2 concentration,the thicknesses of liquid film and gas film both increase.However,the thermal resistance ratio of gas film to liquid film increases gradually,and the gas thermal resistance becomes dominant at high concentrations of CO2.
