Visualization study on the condensation heat transfer on vertical surfaces with a wettability gradient
Visualization study on the condensation heat transfer on vertical surfaces with a wettability gradient
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具有润湿梯度的垂直表面冷凝传热可视化研究
DOI：
10.1016/j.ijheatmasstransfer.2021.122331
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发表时间：
2022-03-01
影响因子：
5.2
通讯作者：
Zhang, Chengbin
中科院分区：
文献类型：
--
作者：
Deng, Zilong;Gao, Shangwen;Zhang, Chengbin
功能表面是强化凝结换热的重要途径。本文采用刻蚀和化学气相沉积的方法设计并制备了具有润湿性梯度的功能表面。通过可视化系统对湿空气在具有润湿性梯度的垂直表面上冷凝的动态相变行为和传热特性进行了实验研究，并与相应的亲水性和疏水性表面进行了比较。结果表明，传统梯度表面湿空气冷凝换热性能上级亲水表面，但由于润湿性梯度较小，在大规模应用中不如疏水表面。考虑到这一点，引入了多层润湿梯度周期性分布的周期性梯度表面，以改善凝结换热。周期性梯度表面具有较大的润湿性梯度，有利于液滴的有效去除和层间、层内作用，从而改善了凝结换热。(c)2021爱思唯尔有限公司版权所有。
The functional surface is a crucial approach to enhance the condensation heat transfer. This paper designs and fabricates a functional surface with wettability gradient by the use of etching and chemical vapor deposition methods. The dynamic phase change behaviors and heat transfer characteristics of humid air condensation on vertical surfaces with wettability gradient have been experimentally investigated and compared with the corresponding hydrophilic and hydrophobic surfaces by a visualization system. The results indicate that the heat transfer performance of humid air condensation on traditional gradient surface is superior to hydrophilic case but inferior to hydrophobic case in large-scale application due to small wettability gradient. Considering this, the periodic gradient surface with periodical layout of multilayer wettability gradient is introduced to improve the condensation heat transfer. The presence of a larger wettability gradient for the periodic gradient surface induces the efficient droplet removal and the preferable inter-layer and intra-layer actions, leading to an improvement of condensation heat transfer. (c) 2021 Elsevier Ltd. All rights reserved.