柱状微结构射流强化换热性能研究

Enhanced Heat Transfer Characteristic of Micro-Pin-Finned Surfaces With Jet Impingement

对电子芯片射流冲击强化沸腾换热进行了实验研究。通过干腐蚀技术在硅片表面加工出交错排列30μm×60μm,50μm×60μm,50μm×120μm,30μm×120μm(宽×高)的柱状微结构,硅片尺寸为10 mm×10 mm×0.5mm。实验工质为FC-72,喷射速度V_j分别为0.5,1和1.5 m·s^(-1),喷嘴数目分别为1,4和9,对应的喷嘴直径分别为3,1.5和1 mm,喷嘴出口到芯片表面的距离分别为3,6和9 mm。实验表明,交错排列柱状微结构的换热效果要好于光滑芯片,临界热流密度(CHF)随着喷射速度的增加而增加。在核态沸腾区的整个喷射速度区间内,S-PF30-120的传热系数和CHF都是最高的。同时,对不同的换热方式进行了比较,包括池沸腾,流动沸腾,射流冲击和流动-喷射复合式沸腾换热。

The boiling heat transfer on staggered micro-pin-finned surfaces with jet impingement was experimentally studied.The dimension of the silicon chips is 10 mm×10 mm × 0.5 mm（length× width × thickness） on the surfaces of which staggered micro-pin-fins with the four dimensions（width × height,50 μm × 60 μm,30 μm × 60 μm,50 μm × 120 μm and 30 μm × 120μm,named S-PF50-60,S-PF30-60,S-PF50-120,S-PF30-120） were fabricated by using the dry etching technique.In the experiment,FC-72 was used as working fluid,the jet velocities were 0.5,1 and 1.5 m·s^（-1）,nozzle numbers were 1,4,and 9,jet diameters were 3,1.5 and 1 mm,and jet-to-target distances were3,6,and 9 mm,respectively.The staggered micro-pin-fins show better heat transfer performance compared with smooth surface.The critical heat flux increases as jet velocity increases.In the nucleate boiling region,chip S-PF30-120 shows the highest heat transfer coefficient and critical heat flux.Meanwhile,the results of different heat transfer modes were compared,including pool boiling,flow boiling,jet impingement and flow-jet combined boiling heat transfer.