Enhancement of Film Condensation Using a Porous Coating: A Theoretical and Experimental Investigation

薄膜强化传热的研究 冷凝与使用高导电性和渗透性多孔 将在固体不可渗透表面上形成涂层。 初步 一个简单的膜状冷凝模型将被扩展，以开发一个更 预测冷凝速率的复杂模型。 传热 将报告水平和倾斜板和管的费率。 先进的模型将在 液体/蒸汽界面，其将考虑蒸汽的影响 阻力、强制对流和相对渗透率。 主要结果 的理论研究将是文件的依赖性 膜厚、速度和温度分布以及局部热 传递系数对多孔基质参数的影响并进行比较 这些结果（一）经典的分析Nusselt和（ii）其他 增强膜冷凝的先进方法（例如，一体或 带凹槽的翅片表面）。 调查的实验部分将 重点是膜状冷凝传热数据的采集， 多孔涂层表面，并对 在广泛的实验条件下的冷凝过程。 传热系数的测量将通过以下方法获得： 在倾斜的多孔涂层板上冷凝氟利昂-113。 验证 的理论膜冷凝模型，它预测了一个 相当大的传热系数，预计由 试验结果

An investigation of the enhancement of heat transfer in film condensation with the use of a highly conductive and permeable porous coating on a solid impermeable surface is to be made. A preliminary simple film condensation model will be expanded to develop a more complex model for predicting the condensation rate. Heat transfer rates for horizontal and inclined plates and tubes will be reported. The advanced model will incorporate matching conditions at the liquid/vapor interface which will account for the effects of vapor drag, forced convection and relative permeability. The main results of the theoretical research will be to document the dependence of the film thickness, velocity and temperature distributions, and local heat transfer coefficient on the porous matrix parameters and to compare these results to (i) the classical analysis of Nusselt and (ii) other advanced methods of enhanced film condensation (e.g., integral or fluted fin surfaces). The experimental part of the investigation will focus on the acquisition of film condensation heat transfer data from a porous coated surface and on photographic observations of the condensation process over a wide range of experimental conditions. Measurements of the heat transfer coefficient will be obtained by condensing Freon-113 on an inclined porous coated plate. Verification of the theoretical film condensation model, which predicts a considerable heat transfer coefficient, is anticipated by the experimental results.