自然对流条件下仿生超疏水表面的抑霜研究  

FROST FORMATION ON A BIONIC SUPER-HYDROPHOBIC SURFACE UNDER NATURAL CONVECTION CONDITIONS

作　　者：勾昱君[1] 刘中良[1] 王皆腾[1] 程水源[1] 

机构地区：[1]北京工业大学环境与能源工程学院"传热强化与过程节能"教育部重点实验室,北京100022

出　　处：《工程热物理学报》2007年第4期631-633,共3页Journal of Engineering Thermophysics

基　　金：国家"973"计划资助项目(No.G2005CB724201);国家自然科学基金(No.50376001);北京市自然科学基金(No.3073014);2006北京市拔尖创新人才选拔计划项目No.20061D0501500186

摘　　要：仿生超疏水表面具有多重纳米和微米级的超微结构,其与水滴的接触角一般在150度以上,本文将这种仿生超疏水表面应用到制冷抑霜实验中,观察其表面上水珠的生成、冻结、初始霜晶的出现以及最终霜晶的特殊形态,与普通金属表面上霜的形成过程相比,这种表面具有很强的抑霜性,在-10℃的冷表面上它能延迟初始霜晶的形成55 min以上,其最终形成的霜晶结构松散,较易去除。在实验中首次发现了在该表面上形成的霜晶形态特异,类似一朵朵菊花。最后本文从理论上分析了这种表面的抑霜机理。Bionic super-hydrophobic surface has a multiple micro-nano-binary structure （MNBS） similar to the microstructure shown on a lotus leaf. This kind of the surfaces has a contact angle of water greater than 150° and a roll angle smaller than 5°. In this paper, the frost deposition phenomena on a bionic super-hydrophobic surface were observed. The surface has a 159° contact angle and is made of many micro bumps. The formation of water droplets, the droplet freezing process, the formation of initial frost crystals and the frost layer structure on a cold bionic super-hydrophobic surface under natural convection conditions were closely observed. The frost layer structure on the super-hydrophobic surface shows remarkable differences to that on a plain copper surface： the structure is weaker, looser, thin and easy to be removed and most importantly, it is of a very special pattern, a pattern similar to chrysanthemum, a frost layer structure that has not been reported before as far as the present authors could know. The experimental results also show that the super-hydrophobic surface has a strong ability to restrain frost growth. The frost deposition on this bionic surface Was delayed for 55 min compared with the plain copper surface under the conditions of a cold plate temperature -10.1℃, air temperature 18.4℃ and relative humidity 40%. A theoretical analysis was also presented to explain the observed phenomena.

关 键 词：仿生超疏水表面 莲花效应 结霜 接触角 成核势垒 

分 类 号：TK124[动力工程及工程热物理—工程热物理]