电场作用下肋表面电对流现象的可视化研究

摘要

电场可强化池态沸腾换热已经得到研究者的普遍认可.以往研究者主要针对光滑表面、加热管或加热线表面的电场强化换热进行研究.在光滑表面增加肋结构可以改变加热面附近的电场分布,从而影响加热面的换热效果.以R113作为实验工质,搭建了可视化的池沸腾实验台,采用高速摄像机记录了肋高为2 mm的加热面在电场作用下的电对流现象.实验发现,电对流随着施加电压的升高而增强,电对流加速了加热面附近流体的混合,破坏了热边界层,使得加热面温度降低从而强化了换热.%It has been widely recognized by researchers that electric field can strengthen the pool boiling heat transfer.Previous researches focused on electrohydrodynamic(EHD) enhancement of pool boiling heat transfer on smooth surface,heating pipe,and heating wire.Adding rectangular rib structure on a smooth surface can change the electrical field distribution and heat transfer ability of a heating surface.High-speed camera was utilized to record the electroconvection phenomena on a surface with rib height of 2 mm using R113 as working fluid.It was found that with the increasing of applied voltage,electroconvection was enhanced.It facilitated the fluid mixing on the heating surface and broke the thermal boundary layer,which decreased the wall temperature and thus enhanced the heat transfer.