泡沫铜肋细小通道热沉中的R134a流动沸腾换热实验研究  

Experimental investigation on flow boiling heat transfer of R134a in a minichannel heatsink with copper foam fins

作　　者：高武焕 付铠 徐向华[1] 梁新刚[1] GAO WuHuan;FU Kai;XU XiangHua;LIANG XinGang(School of Aerospace,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学航天航空学院,北京100084

出　　处：《中国科学：技术科学》2022年第2期333-342,共10页Scientia Sinica(Technologica)

基　　金：国家自然科学基金项目(批准号:51876102)资助。

摘　　要：泡沫金属被广泛应用于换热强化.本文研究了一种泡沫铜肋细小通道热沉的流动沸腾换热性能.泡沫铜的孔隙率为0.8,包含4条宽503μm、高990μm的矩形通道.实验工质为R134a,质量流速范围是595~1213 kg/m^(2)s,热流密度范围是22~172 W/cm^(2).实验得到了不同质量流速、热流密度和干度条件下的换热系数变化规律,分析了不同热流密度下的换热恶化现象.对比了实体肋平行通道热沉的换热性能,发现泡沫铜肋热沉在低热流密度下具有良好的强化换热效果,在高热流密度下反而使换热弱化,反转的热流密度在87~100 W/cm^(2)之间,随流量增大而增大.通过对比流动沸腾流型,解释了泡沫铜肋在高热流密度下引发换热恶化的物理机制.Metal foam is widely used for heat-transfer enhancement.Flow boiling of R134 a in a minichannel heatsink with copper foam fins was studied.The heat sink contained four channels that were 503μm in width and 990μm in depth,and the copper foam fins had a porosity of 0.8.The mass flux in the experiment ranged from 595 to 1213 kg/m^(2)s,and the heat flux was in the range of 22–172 W/cm^(2).Heat transfer coefficients under different mass flow rates,heat fluxes,and qualities were obtained.The heat transfer deterioration phenomenon at different heat fluxes was analyzed.Compared with a solid-fin minichannel heat sink,the heat transfer was enhanced at low heat fluxes,whereas it was weakened at high heat fluxes.The turning point heat flux was between 87 and100 W/cm^(2)and increased as the flow rate increased.Mechanisms of the heat transfer deterioration in the copper foam minichannel heatsink were explained by comparing flow patterns in the two heatsinks at the high heat flux.

关 键 词：泡沫金属 细小通道 多孔肋 流动沸腾 换热 蒸干 

分 类 号：TK124[动力工程及工程热物理—工程热物理]