摘要
对低压环境下闪蒸喷雾冷却不同润湿性表面的实验现象和换热特性开展研究,结果显示:喷雾至亲水表面和光滑铜表面的汽化过程分为四个阶段,即液膜形成阶段、液膜剧烈汽化阶段、固定液膜接触线的汽化阶段和液膜界面收缩阶段。进而研究了表面润湿性、环境压力、工质温度对两种表面温度变化的影响。结果表明,表面温度随时间都呈下降的趋势;亲水表面润湿性较好,喷雾阶段表面温度下降较快;环境压力越低,液体汽化越剧烈,表面的最终平衡温度也越低,但在喷雾阶段存在最佳环境压力使冷却效果最好,本文实验条件下,最佳环境压力为1.9 kPa;工质初始温度对表面最终温度影响很小。
The influence of the surface wettability and pressure on the flash spray cooling was experimentally investigated with the lab-built test platform.The surface modification of red-copper via chemical route reduced its water contact-angle from 94.9° to 38.1°.The preliminary results show that the surface wettability and pressure had a major impact.To be specific,the vaporization on the control/modified Cu-surfaces went through 4 distinctive stages:including the deposition of water film,vigorous vaporization,formation/sustaining and shrinking of the triple-phase interface line.The surface temperature of modified Cu decreased much faster than that of the control sample;as the pressure decreased,the vaporization rate rapidly increased,resulting in a lower final equilibrium temperature.When it comes to the lowest temperature cooled by flash spray,the optimized pressure was 1.9 kPa,depending little on the initial temperature of sprayed distilled-water.
作者
孔淑贤
米梦龙
崔婧格
徐闯
陈鹏
刘璐
Kong Shuxian;Mi Menglong;Cui Jingge;Xu Chuang;Chen Peng;Liu Lu(Department of Power Engineering,North China Electric Power University,Baoding 071003,China)
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2019年第10期845-849,共5页
Chinese Journal of Vacuum Science and Technology
基金
国家自然科学基金项目(51406055)
中央高校基本科研业务费项目(2017MS122)
关键词
低压
喷雾
润湿性
气泡
传热特性
Low pressure
Spray
Wettability
Bubble
Heat transfer characteristics
