肋化结构对两相受限式阵列射流冷却的影响  

Effects of pin-finned array and porous surface on two-phase confined jet-impingement cooling

作　　者：张添[1,2] 闫凯芬 张畅 谢荣建[1,2] 董德平 ZHANG Tian;YAN Kaifen;ZHANG Chang;XIE Rongjian;DONG Deping(Shanghai Institute of Technical Physics,Chinese Academy of Sciences,Shanghai 200083,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院上海技术物理研究所,上海200083 [2]中国科学院大学,北京100049

出　　处：《化工进展》2019年第10期4470-4480,共11页Chemical Industry and Engineering Progress

摘　　要：为了利用两相沸腾换热提高阵列射流冷却热沉性能,使其可以用于更高热流密度散热场景,基于肋化结构对相变换热的促进作用,本文提出了两种复合不同肋化表面的受限式阵列射流冷却热沉结构,并对优化后的热沉的传热、流动特性展开了相关实验研究。两种肋化表面结构分别为:光滑切割针肋(SL1)、外覆烧结多孔层的粗糙针肋(SL2),针肋尺寸均为0.6mm×0.6mm×1mm (长×宽×高),SL2中多孔层颗粒粒径为120~150μm,厚度约为2倍颗粒直径。分布式阵列射流孔板构成5×5的射流单元,每个单元对应4×4针肋阵列,热源总面积30mm×30mm,针肋共计400个。实验使用无水乙醇为工质,得到了热沉在工质流量2.6~12.7mL/s、入口温度283~313K范围时的沸腾曲线和传热曲线。结果表明,两种针肋结构均可以有效实现单相强迫对流换热向两相沸腾换热的转变;增加入口温度或降低工质流量均可以有效地促进相变的发生。在相同工质流量、温度时,SL1较SL2具有更优的单相换热性能,随着加热热流密度的增加,SL2可以在更低壁面过热度下达到沸腾起始点实现过冷沸腾,表现出更佳的传热特性,但SL1可以达到更高的临界热流密度。Two-phase boiling heat transfer can improve the performance of array jet cooling in higher heat flux density heat dissipation situations.Based on the promotion of phase transformation by ribbed structure,two kinds of ribbed surfaces were proposed.Related experimental research on the heat transfer and flow characteristics of the optimized heat sink were carried out.The two ribbed surface structures are:smooth cutting pin fins(SL1),rough needle ribs coated with sintered porous layer(SL2).The pin fins are all 0.6mm×0.6mm×1mm(length×width×height),and for SL2 the particle sizes ranging between 120μm and 150μm with a thickness of about 2 times the particle diameter.The distributed array orifice plate constitutes a 5×5 jet unit,each unit corresponding to a 4×4 pin fin array.The total heat source area is 30mm×30mm and the total number of pin fins is 400.Anhydrous ethanol was used as the working fluid.The boiling curves and heat transfer curves of the heat sink were obtained at the fluid flow rate of 2.6—12.7mL/s and the inlet temperature of 283—313K.The results showed that the two pin-finned structures can effectively realize the transition from single-phase forced convection heat transfer to two-phase boiling heat transfer.Increasing the inlet temperature or reducing the fluid flow rate can effectively promote the phase transition.When using the same fluid flow rate and temperature,SL1 has better singlephase heat transfer performance than SL2.With the increase of heating heat flux density,SL2 can achieve subcooled boiling at lower wall superheat and better heat transfer characteristics,but SL1 achieves higher critical heat flux.

关 键 词：受限式阵列射流 微通道 多孔介质 高热流密度散热 流动沸腾 

分 类 号：TK124[动力工程及工程热物理—工程热物理]