电场作用下锥形孔穴表面微细通道内流动沸腾传热特性  

Flow boiling heat transfer characteristics of in micro channels with tapered cavity surface under electric field

作　　者：罗小平[1] 李桂中 李景生 彭子哲 LUO Xiao-ping;LI Gui-zhong;LI Jing-sheng;PENG Zi-zhe(School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou 510640,China)

机构地区：[1]华南理工大学机械与汽车工程学院,广东广州510640

出　　处：《浙江大学学报（工学版）》2022年第11期2175-2186,共12页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(22178118);广东省自然科学基金资助项目(2019A1515011053).

摘　　要：为了探究电场作用下锥形孔穴表面微细通道内R141b制冷剂的流动沸腾传热特性,研制不同孔穴直径、孔穴密度的锥形孔穴表面微细通道板.在设计系统压力142 kPa、入口温度34.5℃、热流密度7.72~25.11 kW/m^(2)条件下进行流动沸腾试验,对比分析不同孔穴直径、孔穴密度的微细通道电场强化传热效果.对比锥形孔穴表面微细通道和光滑表面微细通道的沿程传热特性,以进一步分析锥形孔穴对电场强化传热效果的影响.为了研究电场对受限气泡的影响,采用COMSOL软件对微细通道内电场分布进行数值模拟,并结合可视化结果分析电场对受限气泡长径比的影响.研究结果表明:在有效热流密度区间内,孔穴密度相同、孔穴直径大的微细通道电场强化传热效果更明显,并且平均饱和沸腾传热系数最大提升了10.1%;孔穴直径相同、孔穴密度大的微细通道,电场强化传热效果更明显,并且平均饱和沸腾传热系数最大提升了19.3%.锥形孔穴表面微细通道的电场强化传热效果优于光滑表面微细通道,电场作用下的微细通道内受限气泡的长径比与无电场时相比更小.The micro channels heat sink with various diameters and densities tapered cavity was made to explore flow boiling heat transfer of the R141b refrigerant in micro channels heat sink with tapered cavity under electric field.The flow boiling experiment was carried out under the conditions of design system pressure of 142 kPa,inlet temperature of 34.5℃and heat flux of 7.72~25.11 kW/m^(2).The electric field enhances heat transfer effect of the micro channels with different cavity diameters and cavity densities was compared and analyzed.The heat transfer characteristics along the path of the micro channels with tapered cavity surface and the micro channels with smooth surface were compared to further analyze the influence of tapered cavity on the heat transfer enhancement by electric field.In order to investigative effect of electric field on confined bubble,the COMSOL software was used to numerically simulate electric field distribution in micro channels and the effect of electric field on confined bubble aspect ratio was analyzed by visualization results.The results showed that the micro channels with the same cavity density but larger cavity diameter in the effective heat flux range had more obvious heat transfer enhancement effect by electric field and average saturated boiling heat transfer coefficient was increased by 10.1%.The micro channels with same cavity diameter but the larger cavity density had more obvious heat transfer enhancement effect by electric field and average saturated boiling heat transfer coefficient was increased by 19.3%.The heat transfer enhancement effect of the micro channels with tapered cavity is better than that of the micro channels with smooth surface under electric field.The aspect ratio of confined bubbles in the micro channels under electric field is smaller than that without electric field.

关 键 词：微细通道 制冷剂 电场 锥形孔穴 流动沸腾 

分 类 号：TK124[动力工程及工程热物理—工程热物理]