Composite porous surfaces of microcavities for enhancing boiling heat transfer
Composite porous surfaces of microcavities for enhancing boiling heat transfer
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DOI：
10.1016/j.ijheatmasstransfer.2021.121513
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发表时间：
2021-10
影响因子：
5.2
通讯作者：
Qifan Li;Z. Lan;Jiang Chun;Rongfu Wen;Xuehu Ma
中科院分区：
文献类型：
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作者：
Qifan Li;Z. Lan;Jiang Chun;Rongfu Wen;Xuehu Ma
通过表面改性增强沸腾传热具有提高能源系统效率和解决电子产品热管理瓶颈的潜力。为了同时提高沸水传热过程的临界热流密度（CHF）和传热系数（HTC），采用粉末烧结-化学改性三步法制备了多孔表面覆盖微腔（MCPS）。系统研究了常压条件下mcps的池沸腾换热特性及气泡动力学特性。结果表明，与普通Cu表面相比，mcps表面的CHF高2.2倍，HTC高2.5倍，核沸腾（ONB）起始率低85%。与pcps相比，MCPS可以增加成核密度，减小气泡离开直径，增加离开频率，这是由于MCPS形成了大量的微腔和毛细管诱导的液体再润湿作用。最后，通过毛细管蠕变试验得到不同表面的吸湿速度，结果表明，吸湿速度与CHF之间存在良好的线性关系。结果表明，具有毛细管弹性的供液可以防止干点膨胀，保持较高的CHF。该研究提供了一种高性能的表面改性，在大功率微电子冷却方面具有重要的工业应用前景。
Enhancing boiling heat transfer by surface modification has the potential to increase the efficiency of energy systems and to address thermal management bottlenecks in electronics. In order to realize simultaneous enhancement of critical heat flux (CHF) as well as heat transfer coefficient (HTC) for boiling heat transfer processes, we developed a porous surface covered by microcavities (MCPS), which was fabricated by the three-step method of a powder sintering technique followed by chemical modification methods. The pool boiling heat transfer properties of MCPSs were systematically investigated in atmospheric pressure conditions, together with the bubble dynamics characteristics. The results showed that compared to plain Cu surfaces (PCSs), a 2.2 times higher CHF, a 2.5 times higher HTC as well as 85% lower onset of nucleate boiling (ONB) were demonstrated on the MCPSs. Owe to the formation of numerous microcavities and capillary-induced liquid rewetting, compared with PCPSs, the MCPS could increase the nucleation density, reduce bubble departure diameter and increase departure frequency. Finally, the wicking velocity of different surfaces obtained from the capillary wickability tests showed that there was a good linear relationship between the wicking velocity and CHF. The results showed that the liquid supply with capillary wickability could prevent the expansion of dry spots and maintain a higher CHF. This study provides a high-performance surface modification, which leads to significant industrial application prospects for high-power microelectronics cooling.