基于表面亲水改性的微通道高热流流动沸腾换热性能优化  

Optimization of Flow Boiling Heat Transfer Performance in Micro-Channel under High Heat Flux based on Surface Hydrophilic Modification

作　　者：喻祖康 舒碧芬[1] 黄妍 江景祥 YU Zu-kang;SHU Bi-fen;HUANG Yan;JIANG Jing-xiang(Institute for Solar Energy Systems(ISES),Sun Yat-Sen Univeisity,Guangzhou,China,Post Code:510006)

机构地区：[1]中山大学太阳能系统研究所,广东广州510006

出　　处：《热能动力工程》2020年第12期94-100,共7页Journal of Engineering for Thermal Energy and Power

基　　金：国家自然科学基金(U1707603);广东省自然科学基金重点项目(2014A030311050)。

摘　　要：制备了接触角为0°~70°的3种不同润湿性表面微通道,以R-134a为工质进行了可视化流动沸腾实验,研究不同进口干度、热流密度下,表面润湿性对微通道流态与传热特性的影响,并通过表面微观结构和流态观测对其潜在流动换热特性机理进行分析。实验结果表明:表面亲水改性能显著提高沸腾流动微通道的局部散热性能和散热均匀性,平均散热性能得到显著提高。在较低热流密度下,超亲水表面平均换热系数比普通光滑表面最大提高了约64%,而亲水表面平均换热系数比普通光滑表面最大提高了27%;在高热流密度下,超亲水表面换热系数比普通光滑表面最大提高了约80%,而亲水表面平均换热系数比普通光滑表面最大提高了约50%。通过可视化观测发现,高热流高干度下,普通光滑表面微通道内壁面发生了严重干涸现象,导致传热系数快速下降,而在超亲水表面并未发生干涸,表明通过超亲水表面改性能显著优化高热流微散热器散热,有效防止干烧导致的器件寿命下降。Three different wettability surfaces of the contact angle of 0°-70° were prepared on aluminum-based micro-channels.Saturated flow boiling experiments with R-134 a in these three different surface wettability micro-channels were conducted to investigate the effect of different surface wettability on the heat transfer coefficient under different inlet vapor quality and heat flux density.The experimental results showed that surface hydrophilic modification significantly improves the local heat transfer coefficient and heat dissipation uniformity of the boiling flow in micro-channel,and the average heat transfer coefficient is also significantly improved.The maximum average heat transfer coefficient of super-hydrophilic surface is about 64% higher than that of smooth surface under low heat flux,while the hydrophilic surface increases the heat transfer coefficient by 27% maximum compared to the smooth surface.In particular,under the high heat flux density,the maximum average heat transfer coefficient of super-hydrophilic surface is about 80% higher than that of smooth surface,while the hydrophilic surface increases the heat transfer coefficient by 27% maximum against the smooth surface.Under the condition of high heat flux and high inlet vapor quality,it was found that dry walls are prone to occur on the inner walls of smooth surface,while the excellent surface wettability can prolong the life of the device by effectively relieving wall dryness.

关 键 词：微通道 流动沸腾传热 微结构 表面改性 

分 类 号：TK124[动力工程及工程热物理—工程热物理]