香港城市大学王鑽開团队报道了在1000°C以上抑制莱登弗罗斯特效应用于持续热冷却。相关研究成果发表在2022年1月26日出版的《自然》。
众所周知，莱登弗罗斯特效应，即水滴在热固体上的悬浮，会恶化高温下的传热。莱登弗罗斯特点可以通过纹理材料来提高，以利于固液接触，并通过在表面布置通道来将润湿现象与蒸汽动力学分离。然而，在广泛的温度范围内最大化莱登弗罗斯特点和热冷却可能是相互排斥的。
该文中，研究人员报告了一种合理设计的结构化热防护罩，它可以在1150°C的温度下抑制莱登弗罗斯特效应，也就是说，比之前达到的温度高出600°C，同时保持热传递。该设计包括用作热桥的钢柱、一个嵌入的用于吸走和扩散液体的绝缘膜，以及用于蒸汽排空的U形通道。热性能和几何性能截然不同的材料共存，共同将通常均匀的温度转变为不均匀的温度，在所有温度下产生横向芯吸，并增强热冷却。结构化防热盔甲只受熔点的限制，而不是设计上的失误。这种材料可以是柔性的，因此可以连接到基板上，否则会对结构造成挑战。该战略具有在超高固体温度下实现高效水冷却的潜力，是迄今为止尚未发现的特性。
附：英文原文
Title: Inhibiting the Leidenfrost effect above 1,000 °C for sustained thermal cooling
Author: Jiang, Mengnan, Wang, Yang, Liu, Fayu, Du, Hanheng, Li, Yuchao, Zhang, Huanhuan, To, Suet, Wang, Steven, Pan, Chin, Yu, Jihong, Qur, David, Wang, Zuankai
Issue&Volume: 2022-01-26
Abstract: The Leidenfrost effect, namely the levitation of drops on hot solids1, is known to deteriorate heat transfer at high temperature2. The Leidenfrost point can be elevated by texturing materials to favour the solid–liquid contact2,3,4,5,6,7,8,9,10 and by arranging channels at the surface to decouple the wetting phenomena from the vapour dynamics3. However, maximizing both the Leidenfrost point and thermal cooling across a wide range of temperatures can be mutually exclusive3,7,8. Here we report a rational design of structured thermal armours that inhibit the Leidenfrost effect up to 1,150°C, that is, 600°C more than previously attained, yet preserving heat transfer. Our design consists of steel pillars serving as thermal bridges, an embedded insulating membrane that wicks and spreads the liquid and U-shaped channels for vapour evacuation. The coexistence of materials with contrasting thermal and geometrical properties cooperatively transforms normally uniform temperatures into non-uniform ones, generates lateral wicking at all temperatures and enhances thermal cooling. Structured thermal armours are limited only by their melting point, rather than by a failure in the design. The material can be made flexible, and thus attached to substrates otherwise challenging to structure. Our strategy holds the potential to enable the implementation of efficient water cooling at ultra-high solid temperatures, which is, to date, an uncharted property.
DOI: 10.1038/s41586-021-04307-3
Source: https://www.nature.com/articles/s41586-021-04307-3