標題: The suppression effect of easy-to-activate nucleation sites on the critical heat flux in pool boiling
作者: Liu, Yi
Lu, Ming-Chang
Xu, Dongyan
機械工程學系
Department of Mechanical Engineering
關鍵字: Microstructured hydrophobic-hydrophilic surfaces;Easy-to-activate nucleation sites;Boiling heat transfer;Critical heat flux;Heat transfer coefficient
公開日期: 1-七月-2018
摘要: We report experimental studies of the role of easy-to-activate nucleation sites in pool boiling on hybrid hydrophobic-hydrophilic surfaces. Microstructured surfaces with controlled wettability and nucleation sites are designed and fabricated to investigate their individual and collective effects on the boiling heat transfer performance. Our results reveal that excellent critical heat flux (CHF) up to 231.5 W/cm(2) is attainable only when the surface has good wettability but is free of easy-to-activate nucleation sites. However, with the presence of easy-to-activate nucleation sites on the boiling surface, only limited CHFs can be achieved irrespective of the surface wettability, suggesting a suppression effect of nucleation sites on the CHF. Based on the previous experimental observation of the dynamic network-like wetting pattern at high heat fluxes, a wetting-deterioration mechanism is proposed to explain the suppression effect of easy-to-activate nucleation sites on the CHF. Easy-to activate nucleation sites continuously generate bubbles that pose a large flow resistance for the liquid to wet the hot surface and thus lead to early dry-out.
URI: http://dx.doi.org/10.1016/j.ijthermalsci.2018.03.007
http://hdl.handle.net/11536/145013
ISSN: 1290-0729
DOI: 10.1016/j.ijthermalsci.2018.03.007
期刊: INTERNATIONAL JOURNAL OF THERMAL SCIENCES
Volume: 129
起始頁: 231
結束頁: 237
顯示於類別:期刊論文