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论文类型：期刊论文

发表时间：2012-08-01

发表刊物：ACTA PHYSICA SINICA

收录刊物：SCIE、PKU、ISTIC、Scopus

卷号：61

期号：15

ISSN号：1000-3290

关键字：infrared thermography; surface temperature; dropwise condensation; critical subcooling

摘要：The invistigations on dropwise condensation process and the mechanism of heat transfer enhancement are usually based on the droplet distribution and the movement principle of droplets on condensing surface. In the meanwhile, a single droplet is treated as a stable individual and the movement property inside the droplet is rarely considered. With infrared thermography, the surface temperature distribution of condensate droplet during steam dropwise condensation process is observed. The result shows that the temperature of droplet surface first decreases and then increases and up to a value higher than the initial one as the droplet migrates from one position to another. The droplet will roll and the surface film would be tracked when the droplet moves on the hydrophobic surface. With the convection inside the droplet, condensate near the wall moves to the surface side. The analysis of surface temperature evolution of droplet indicates that the continuous condensation on droplet surface may occur when the surface subcooling exceeds a critical value. The direct condensation on large droplet surface can be promoted by the dynamic process such as droplet coalescence or falling off, which provides a new approach to the condensation heat transfer enhancement.