微纳结构铜表面低液位池沸腾实验研究

Experimental study pool boiling on micro/nano-structured copper surface in shallow liquid

中文关键词: 微纳结构  液位  池沸腾  传热系数  

英文关键词: micro/nano-structure  liquid level  pool boiling  heat transfer coefficient

中文摘要:

      采用两步电镀法，在改变电流密度的情况下制备出具有不同微纳结构和润湿特性的A、B两个表面，并应用于低液位饱和池沸腾的实验研究中。通过与铜表面对比，发现两个表面在低热流密度情况下，传热系数要高于铜表面，但液位降低时传热系数提升幅度较小，原因在于铜表面沸腾气泡较大，液位降低气泡脱离有很大影响，而A、B表面沸腾气泡较小，液位降低主要对气泡扰动产生影响；当热流密度增大后，两个微纳结构表面气泡聚合严重，传热系数要低于铜表面，而且三个表面在高热流密度下，液位降低提升传热系数的幅度都有所降低。

英文摘要:

      A two-step electrodeposition method was applied to fabricate two micro/nano- structured copper surfaces, and the wettability of these surfaces was changed to hydrophobic. The boiling performance of these surfaces and plain copper surface were compared in shallow water. For low heat flux applied, the heat transfer coefficients of the electrodeposited surfaces were higher than copper surface, however with the water level decreasing, the increasing rate of their heat transfer coefficients was lower than copper surface’s. For copper surface, decreasing water level hindered the detachment of the bubbles, and for the electrodeposited surfaces, decreasing water level weakened the bubble disturbance. For high heat flux, the performance of electrodeposited surfaces deteriorated due to the severe coalescence of the bubbles, and the increase of the heat transfer coefficients of electrodeposited surfaces and copper surface was unobvious thereafter.