摘要
为研究差异化疏水结构表面蒸汽滴状冷凝传热特性,首先在铜表面通过化学刻蚀法制备了不同的CuO与Cu(OH)_2微纳米复合微结构,通过十八硫醇自组装进一步修饰后,获得了具有不同静态接触角和表面能的差异化疏水表面。实验研究了不同微结构及其接触角对滴状冷凝传热性能的影响,并对冷凝传热过程中液滴在微结构表面的合并、脱落过程进行了可视化研究。结果表明,接触角相近、微结构不同的CuO-Ⅰ与Cu(OH)_2表面冷凝传热性能相近,约为光滑表面的1.5倍。接触角为125°的CuO-Ⅱ表面的冷凝传热性能明显高于CuO-Ⅰ表面,约为光滑表面的3倍。同时,相同过冷度下,CuO-Ⅰ表面冷凝液滴的合并与脱落频率明显低于CuO-Ⅱ表面。
In order to study the heat transfer of dropwise condensation Oil differentiated micro-nano structure surfaces, various CuO and Cu （OH）2 micro-nano structures were firstly prepared by chemical etching on the surfaces of copper. Then, these micro-nano structures were modified respectively with n-Octadecyl mercaptan by using self-assembled monolayers （SAMs） technique, and the differentiated hydrophobic surfaces were obtained with different static contact angle and surface energy. Subsequently, the effects of differentiated microstructures and contact angles on the heat transfer performances of the dropwise condensation were studied experimentally, and the mechanism of droplets coalescence and sweeping in the process of condensation heat transfer was also studied visually The experimental results showed that the heat transfer of CuO-I surface with similar contact angle and different micro structures was very close to that of Cu（OH）2 ,which was 1.5 times of that of smooth surface. However, the condensation heat transfer performance of CuO- II surface, with contact angles of 125°, was significantly larger than that of CuO-I, which was about 3 times of the heat transfer of smooth surface. Furthermore, the both coalescence and sweeping frequencies of droplets on CuO-I surface was significantly lower than that of CuO- II under the similar subcooling.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2018年第2期428-433,共6页
Journal of Engineering Thermophysics
基金
国家自然科学基金资助项目(No.5130614)
关键词
滴状冷凝
超疏水
传热性能
dropwise condensation
superhydrophbic
heat transfer performance
