表面多孔涂层对强化凝结换热的影响

为探讨新的强化凝结换热的方法，考虑多孔层界面液体间的剪切效应，建立了蒸气在具有多孔涂层倾斜表面膜状凝结换热的物理数学模型。数值计算结果表明：在一定范围内，表面过冷度、多孔涂层的厚度、渗透率和有效导热系数的增大都不同程度地强化凝结换热，表面倾角引起的彻体力的变化对强化凝结换热的影响很大。与Ｎｕｓｅｌｔ理论预示值对比显示：多孔涂层具有明显的强化膜状凝结换热的作用，而多孔层的弥散作用是强化凝结换热的主导因素。多孔涂层特征参数的优化研究可为进一步的实验研究提供理论指导。

Effect of porous coating on condensa tion heat transfer enhancement

To investigate the performance of condensation heat transfer on the surface with porous coating, a mathematical model for film condensation on an inclined plate with a porous layer coating was established by considering the liquid stress effect at the porous layer interface. The effects of the characteristic properties of porous coating on film condensation were discussed. The dependence of heat transfer on the inclined angle is presented. Comparison with the prediction of Nusselt theory and Renken's model indicates that the porous coating enhances the condensation heat transfer obviously and the dispersion effect within the porous layer is the decisive factor for the enhancement.