降压环境下液滴在不同润湿性表面汽化过程实验研究  

Droplet Vaporization on Warm Surface in Rapid Decreasing Pressure: An Experimental Study

作　　者：崔婧格 孔淑贤 刘亿鑫 米梦龙[1] 杨红月[1] 刘璐[1] Cui Jingge;Kong Shuxian;Liu Yixin;Mi Menglong;Yang Hongyue;Liu Lu(School of Energy,Power and Mechanic Engineering,North China Electric Power University,Baoding 071003,China)

机构地区：[1]华北电力大学能源动力与机械工程学院,保定071003

出　　处：《真空科学与技术学报》2018年第11期925-929,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专项资金资助项目(2017MS122;2015MS105)

摘　　要：对降压环境下液滴在不同润湿性表面的汽化过程进行了实验研究,对比了在亲水和疏水表面上液滴汽化过程的无量纲尺寸变化,分析了环境压力和表面温度对亲水表面液滴汽化过程的影响。实验结果显示:降压过程中液滴在热表面的汽化过程经历四个阶段:初始状态、降压的快速汽化阶段、定接触线汽化阶段和快速收缩阶段。相同工况下,由于疏水表面的气泡数更多,抑制了液滴接触半径的收缩,液滴生存时间更长。在亲水表面上环境压力越低、表面温度越高,液滴汽化越剧烈,并且定接触线汽化阶段占整个汽化过程的比例越大。Herein, we experimentally addressed the size variation in droplet vaporization on copper surfaces. The influence of the vaporization conditions, including the pressure decrease-rate, surface warmness （ 25 - 30℃ ） and hydrophilic/hydrophobic propeties, on the droplet＇ s size variation was investigated with the experimental setup, equipped with charge-coupled device （CCD） video cameras. The results show that the vaporization conditions had a major impact. To be specific, the vaporization on went through four distinctive stages ： the initial, rapid vaporization, constant contact radius and rapid contraction stages. The droplet survived much longer on the hydrophobic surfaces because a larger number of bubbles significantly slowed down the shrinkage of the droplet contact radius. On the hydrophilic surfaces, the droplet vaporized much faster with an increase of surface temperature and with a decrease of pressure, resulting in a longer time of constant contact radius vaporization stage.

关 键 词：降压 液滴 润湿性 汽化 尺寸变化 

分 类 号：TK124[动力工程及工程热物理—工程热物理]