矩形槽强化膜状冷凝换热数值分析与实验研究

Numerical analysis and experimental investigation for enhanced heat transfer of film condensation on a rectangular flute

研究了饱和蒸汽在垂直矩形槽表面的层流膜状冷凝换热,对物理模型进行了适当的简化,建立了冷凝液的流体流动方程,并与二维导热方程耦合,用数值方法解方程,通过迭代,得到了传热量与坐标z的关系。为了验证数值分析,建立了饱和蒸汽在矩形槽表面冷凝的实验模型和实验装置,测量了在不同的温差下的热通量,并与计算热通量做了对比。结果表明,热通量数值分析值与实验值吻合较好,最大偏差不超过10%,说明关于矩形槽强化冷凝换热的数值分析具有可行性,可用于矩形槽的参数设计和换热计算。

The heat transfer of laminar film condensation of saturated vapor on a vertical rectangular flute was studied.The physical model was properly simplified.The fluid flow equations of condensate were established,and coupled with the two-dimensional thermal conduction equation.By solving the equations with numerical method,the relation between heat transfer rate and z-coordinate was obtained iteratively.In order to verify the numerical analysis,the experimental model and apparatus were set up.The experimental heat fluxes under different temperature differences were obtained,and were compared with the calculations.Both the results are in good agreement,with a maximum deviation of 10%.The numerical analysis for enhanced heat transfer of film condensation on a rectangular flute is feasible,and can be applied to the parameter design and the heat transfer rate calculation of rectangular flute.