Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
School of Chemistry, Beihang University, Beijing, 100191, P. R. China.
Adv Mater. 2023 Jun;35(26):e2210557. doi: 10.1002/adma.202210557. Epub 2023 May 17.
Enhanced boiling heat transfer via surface engineering is a topic of general interest for its great demand in industrial fields. However, as a dynamic interfacial phenomenon, a deep understanding of its process and mechanism, including liquid re-wetting and vapor departure, is still challenging. Herein, a micro-/nanostructured Cu surface containing a periodic microgroove/pyramid array with rich nanowrinkles is designed, where superspreading (<134.1 ms) of organic cooling agents highly boosts the liquid re-wetting process, causing a discontinuous solid-liquid-vapor three-phase contact line and ultralow under-liquid bubble adhesion force (≈1.3 µN). Therefore, a characteristic, ultrafast jet-flow boiling (bubbles rapidly ejected in multiple strips) is obtained on this surface, giving a priority to nucleation (superheat ≈ 1.5 °C) and simultaneously enhancing the critical heat flux and heat-transfer coefficient by up to 80% and 608%, respectively, compared with a flat surface. In situ observation and analysis of the nucleation, growth, and departure of micro-sized jet-flow bubbles reflects that microgrooves/pyramids with nanowrinkles promote the latent heat exchange process by superspreading-induced ultrafast liquid re-wetting and constant vapor film coalescing. Based on the designed structures, high-performance phase-change cooling for central processing unit heat management in supercomputer centers is accomplished with an ultralow power usage effectiveness (PUE < 1.04).
通过表面工程增强沸腾传热因其在工业领域的巨大需求而成为一个备受关注的话题。然而，作为一种动态的界面现象，对其过程和机制的深入理解，包括液体再润湿和蒸汽脱离，仍然具有挑战性。在此，设计了一种包含周期性微槽/金字塔阵列和丰富纳米皱纹的微/纳结构化铜表面，其中有机冷却剂的超扩展（<134.1ms）极大地促进了液体再润湿过程，导致不连续的固-液-气三相接触线和超低的下液泡附着力（≈1.3µN）。因此，在这种表面上获得了一种特征性的超快射流沸腾（气泡以多条带迅速喷出），优先进行成核（过热度≈1.5°C），同时将临界热流密度和传热系数分别提高了 80%和 608%，与平面相比。微射流气泡的成核、生长和脱离的原位观察和分析表明，具有纳米皱纹的微槽/金字塔通过超扩展诱导的超快液体再润湿和恒定蒸汽膜聚合并促进了潜热交换过程。基于所设计的结构，在超级计算机中心的中央处理单元热管理中实现了高性能的相变冷却，超低的电源使用效率（PUE<1.04）。
