摘要
研究了光滑表面和不同粒径铜粉烧结的多孔表面上,以液氨为工质的喷雾相变冷却的传热特性。研究发现在相同工况下,由于多孔结构的毛细作用和潜在的有效汽化核心数强化了多孔表面的换热性能,多孔表面的换热性能远高于光滑表面。随着烧结铜粉粒径的减小,在核态沸腾区的换热效果增强;对于烧结粒径为28μm和49μm的多孔表面,在流量为0.0133m3/(m2.s),热流密度为367 W/cm2时,换热系数分别高达100612 W/(m2.K)和96464W/(m2.K);当流量从0.0133m3/(m2.s)提高到0.0181m3/(m2.s)时,维持其他实验工况不变,多孔表面的核态沸腾延长,并且推迟临界热流(CHF)密度出现;在热流密度达367 W/cm2时,0.0181m3/(m2.s)流量下的换热系数达到147503W/(m2.K),换热系数相对于0.0133m3/(m2.s)时提高了约47%。
The heat transfer characteristics of the spray cooling with ammonia are experimentally investigated on a smooth surface and two porous surfaces with different sintered grain sizes. It is found that porous surfaces significantly enhance the heat transfer as a result of wicking action of porous structure and potential active nucleation sites. In nucleate boiling region, with the decrease of sintered grain size, heat transfer of porous surfaces performs better; the maximum heat transfer coefficients of 100612 W/（m2 .K） and 96464 W/（m2. K） are achieved with the heat flux of 367 W/cm2 at the flow rate of 0. 0133 m3/（m2 . s） for the porous surfaces with sintered grain sizes of 28μm and 49 μm. When the flow rate increases from 0.0133 m3 /（m2 . s） to 0.0181 m3 /（m2 .s）, the appearance of critical heat flux （CHF） density is delayed and the heat transfer coefficient is increased by 47% to reach 147503 W/（m2 .K） at the heat flux of 367 W/cm2.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2013年第3期29-34,共6页
Chinese Journal of Lasers
基金
国家973计划(2012CB720403)
国家自然科学基金(50906102)
重庆市自然科学基金项目(CSTC2011jjA90015)
教育部留学回国人员科研启动基金(教外司留[2010]1561号)
中央高校基本科研业务费科研专项自然科学类项目(CDJZR10140012)资助课题
关键词
激光器
喷雾冷却
多孔表面
流量
lasers
spray cooling
porous surface
flow rate
