微结构表面封闭式喷雾冷却传热特性  

Heat transfer characteristics in closed-loop spray cooling of micro-structured surfaces

作　　者：张伟[1] 王照亮[1] 徐明海[1] 

机构地区：[1]中国石油大学储运与建筑工程学院,山东青岛266555

出　　处：《强激光与粒子束》2012年第9期2053-2058,共6页High Power Laser and Particle Beams

基　　金：国家自然科学基金项目(51176205);山东省自然科学基金项目(Y2008F42);山东省中青年科学家科研奖励基金项目(Y2009CL017)

摘　　要：以蒸馏水为工质,在闭式循环喷雾冷却系统上,变化喷雾流量,研究了表面几何结构对喷雾传热性能的影响。从对流换热和相变换热比例关系的角度,对喷雾换热机理进行了实验研究。结果表明:与光滑表面相比,微结构表面可明显增强喷雾换热强度,这主要归因于相变换热的增强。表面温度较低时,直肋面换热效果最好;增大流量,光面换热增强,而直肋面变化不明显。表面温度较高时,方肋面换热效果最好;随着流量增大,所有面换热均增强。对于微结构表面,相变换热份额均大于50%,故而以相变换热为主;而光滑表面,即使在温度较低时,相变换热份额也大于20%。临界热流密度与三相接触线长度正相关,流量为15.9mL/min时,方肋面、直肋面和光面的临界热流密度依次为159.1,120.2,109.8W/cm2,蒸发效率分别为96.0%,72.5%,67.1%。With water as the working fluid, experiments on the heat transfer characteristics of spray cooling of micro-structured surfaces were performed in a closed loop system. Experimental data were analyzed in the view of the ratio between convective heat transfer and phase change heat transfer. The results indicate that heat transfer is obviously enhanced for micro-channel surfaces relative to the flat surface because of higher phase change heat transfer. For the geometries tested at lower surface temperature, the straight finned surface has the largest heat flux; while at higher surface temperature, the cubic pin finned surface has the largest heat flux. Heat fluxes of all the surfaces grow with increasing flow rates, except for the straight finned surface under lower surface temperature. The ratio of phase change to total heat transfer is bigger than 20% for the flat surface, and higher than 50% for micro-structured surfaces. Critical heat fluxes of 159.1, 120.2, and 109.8 W/cm2 are attained for cubic pin finned, straight finned and flat surfaces respectively when the flow rate is 15.9 mL/min, and the corresponding evaporation efficiencies are 96.0%, 72.5%, 67.1%.

关 键 词：喷雾冷却 微结构表面 相变换热 临界热流密度 

分 类 号：TK124[动力工程及工程热物理—工程热物理]