波纹管管外冷凝传热系数计算模型

推导了波纹管表面张力液膜滞流冷凝传热系数计算式,引入重力修正系数校正重力的影响,并通过实验确定了重力修正系数,得到波纹管冷凝传热系数计模型。计算值与实验结果较为一致,误差小于6%。计算模型物理意义较为明确,可以清楚地分析波纹管强化传热的主要因素。研究表明,传热系数的提高是由表面张力和波纹表面结构使波纹表面冷凝负荷降低这两方面决定。

Calculation Model of the Condensation Heat Transfer Coefficients Outside Bellows

The formula of the condensation heat transfer coefficient of the fluid film laminar flow of the surface tension of the bellows was deduced.The gravity correction coefficient was introduced to modify the influence of gravity,the gravity correction coefficient was determined with experiments,and the calculation model of the condensation heat transfer coefficients of the bellows was obtained.The calculated value basically agreed with the experimental value,the error was less than 6%,the physical meaning of the calculation model was definite,the major factors of the reinforced heat transfer of the bellows could be clearly analyzed.The investigation shows that the increase of the heat transfer coefficients was determined with the reasons that the surface tension was higher than the gravity and the surface structure of corrugation decreased the condensation load of the corrugation surface.