Abstract: Micro-encapsulated phase change material slurry (MEPCMs) is a novel kind of functional thermal fluid, which has great potential in the field of electronic thermal management, thermal storage, etc. To improve the thermal management performance of high-power density electronic devices, a dual-enhanced heat transfer method with the combination of MEPCMs and metal foam was employed to improve the cooling performance of mini-channel heat sink in the present study. Numerical methods were utilized to investigate the heat transfer capability, flow resistance, and overall performance evaluation criteria (PEC) by considering the effects of MEPCMs mass fractions (5wt%, 10wt%, and 20wt%), inlet velocities, and metal foam filling ratios. The results indicated that the maximum temperature of metal foam mini-channel decreased and pressure drop increased with increasing the mass fraction of MEPCMs. At an inlet velocity of 0.06 m/s, increasing the mass fraction from 5wt% to 20wt%, the pressure drop increased by 2.09 times. 5wt% MEPCMs presented the best comprehensive heat transfer performance, and the PEC value was improved by 8.15%~12.18% compared with pure water. The filling ratio of the metal foam also significantly affected the heat transfer performance of the microchannel, and the cooling performance was best when the mini-channel was fully filled with metal foam. For the entire range of flow velocities, using 5wt% MEPCMs as the coolant, average Nuave of mini-channel heat sink fully filled with metal foam was 9.06 times of the empty mini-channel heat sink, and the pressure drop came to 56.91 times. With the comprehensive consideration of heat transfer enhancement and flow resistance, the PEC value could reach up to 2.61. The present findings could provide theoretical guidelines for developing more coefficient and compact liquid-cooled electronic devices.

Key words: metal foam, micro-encapsulated phase change material slurry, heat transfer, micro-channel, numerical simulation

摘要： 相变微胶囊悬浮液(MEPCMs)是一种新型传热功能热流体，在热管理、储能等领域极具发展潜力。为提高能流密度电子器件的热管理性能，本工作采用相变微胶囊悬浮液和金属泡沫作为双重强化换热手段来提升微通道的冷却特性。利用数值方法研究了MEPCMs质量分数(5wt%, 10wt%和20wt%)、入口流速、金属泡沫填充率对微通道换热性能、流动阻力及综合换热性能的影响规律。结果表明，金属泡沫微通道的最高温度随着MEPCMs质量分数增大而降低，压降随着质量分数增大而增加；流速为0.06 m/s时，质量分数从5wt%增大到20wt%，压降增加了2.09倍。5wt%的MEPCMs的综合换热性能最好，综合能效因子较纯水提升了8.15%~12.18%。金属泡沫的填充率会显著影响微通道的换热性能，完全填充金属泡沫微通道的冷却性能最好。在整个流速范围内，以5wt%的MEPCMs为冷却工质，完全填充金属泡沫微通道Nuave为空微通道的9.06倍，流动压降为空微通道的56.91倍，综合能效因子可达2.61。本研究结果可为开发高效、紧凑的液冷电子器件散热装置提供理论指导。

关键词: 金属泡沫, 相变微胶囊悬浮液, 传热, 微通道, 数值模拟