Condensation heat transfer on phase change slippery liquid-infused porous surfaces
Condensation heat transfer on phase change slippery liquid-infused porous surfaces
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DOI：
10.1016/j.ijheatmasstransfer.2021.122384
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发表时间：
2022-04-01
影响因子：
5.2
通讯作者：
Zhang, Peng
中科院分区：
文献类型：
--
作者：
Gulfam, Raza;Huang, Ting-en;Zhang, Peng
介绍了相变滑液多孔表面(PC-SLIPS)，重点研究了表面润湿特性和液滴动力学对水蒸气冷凝和相应的换热的影响。将石蜡-二甲苯溶液浸渍到功能化的纳米多孔铜板中，制备了PC-SLIPSS。研究发现，液滴动力学分别受固体相(48℃)、糊状相(58℃)和液体相(66℃)的低附着力(滑动角α为45+/-5度)、高附着力(α为60+/-5度)和滑态(α为3+/-1度)的影响。除了润湿性和液滴粘附性的表征外，还在自制的真空辅助冷凝实验台上对PC-SLIPSS上的冷凝换热进行了详细的研究。根据所注入相变材料的相态，揭示了两种主要的滴状凝结机制，如固相和糊状相中的聚结诱导液滴脱落和液滴扫掠，而在没有额外聚结的情况下，在液态中报道了离散液滴的脱落和扫掠。在较低的过冷温度下，与纯铜表面相比，液态铜滑板的换热系数提高了约136.8%。在PC-SLIPSS的液相中，进一步进行了滴状冷凝的理论传热模拟，以阐明单个液滴与液滴数密度耦合的传热机理。严格的冷凝实验证实，PC-SLIPSS的运行耐久性可达8+/-1h。总而言之，不同的润湿特性、不同的液滴脱落机理、有前景的滴状冷凝模式、高的液相换热系数和有效的随时间变化的耐久性是PC-SLIPS的显著发现，使其成为具有竞争力的替代品。最重要的含义是，如果液滴动力学效率低下，滴状冷凝模式也可能表现不佳。(C)2021年爱思唯尔有限公司。保留所有权利。
Phase change slippery liquid-infused porous surfaces (PC-SLIPSs) are presented with emphasis on surface wetting characteristics and droplet dynamics influencing the water vapor condensation and the corre-sponding heat transfer. The functionalized nano-porous copper plate is infused with paraffin wax-xylene solution via dip coating method to prepare PC-SLIPSs., where the droplet dynamics are found to be af-fected by low adhesion (sliding angle alpha of 45 +/- 5 degrees), high adhesion (alpha of 60 +/- 5 degrees) and slippery (alpha of 3 +/- 1 degrees) states enabled by solid (at 48 degrees C), mush (at 58 degrees C) and liquid (at 66 degrees C) phases, respectively. Be -sides the wettability and droplet adhesion characterization, the condensation heat transfer is particularly explored on PC-SLIPSs in custom-built vacuum-assisted condensation rig. Two major dropwise conden-sation mechanisms are unveiled depending on the phase of the infused phase change material, such as coalescence-induced droplet shedding coupled with droplet sweeping in the solid and mush phases, while discrete-droplet shedding and sweeping in the absence of additional coalescence are reported in the liquid phase. Approximately, 136.8% higher heat transfer coefficients for PC-SLIPS in the liquid phase are reported when compared with the pristine copper surface at low sub-cooling temperatures. In the liquid phase of PC-SLIPSs, theoretical heat transfer modeling on dropwise condensation has been further carried out to elucidate the heat transfer mechanism via a single droplet coupled with the droplet num -ber density. The operational durability of PC-SLIPSs has been found to last for 8 +/- 1 h as confirmed during rigorous condensation experiments. In summary, different wetting features, various droplet shed-ding mechanisms, promising dropwise condensation modes, high heat transfer coefficient in the liquid phase, and effective time-dependent durability are the salient findings associated with PC-SLIPSs, ren-dering them competitive alternatives. The most important implication is that the dropwise condensation mode can also underperform if the droplet dynamics is inefficient. (c) 2021 Elsevier Ltd. All rights reserved.