混合润湿微结构楔形通道表面池沸腾换热研究
Study on Pool Boiling Performance of the Mixed Wettability Microstructure Surface With Wedge-shaped Channels
唐叶 1王雪丽 1姬长发 1张鹏举 1张永海2
作者信息
- 1. 西安科技大学能源学院,西安 710054
- 2. 西安交通大学化学工程与技术学院,西安 710049
- 折叠
摘要
为研究微结构楔形通道对池沸腾换热性能的影响,本文设计加工了微柱区域与光滑通道面积比近似为1∶1的3种混合润湿性结构表面(分别为雪花表面、多星表面和少尖表面),并进行了以FC-72为工质的池沸腾换热性能研究.结果表明,对于3种结构表面,汽泡首先在疏水微柱阵列区域生成、长大,然后横向滑移到光滑亲水通道,在该通道内继续生长直至脱离.少尖表面的光滑通道开口朝向换热面中心,且越靠近中心处通道越宽.冷却液体能迅速地向生成汽泡的微柱区域供应,同时大汽泡在光滑通道内及时脱离,因此少尖表面的池沸腾换热性能最好.随着过冷度增大,各表面CHF增大.换热表面蒸汽柱底部汽膜的出现严重阻碍了液体向换热面的供应,导致局部干涸并引发了 CHF.
Abstract
To study the effect of micro-structured surface with wedge-shaped channel on pool boil-ing heat transfer performance of FC-72,three kinds of mixed wettability surfaces with area ratio of the micro-pillar region to the smooth channel region of approximately 1∶1 were fabricated in this study(the surfaces were denoted as the Snowflake surface,Multi star surface,and Less tip surface).The experimental results indicated that for the three surfaces,bubbles are firstly generated and grown in the hydrophobic micro-pillar array region,and then slid laterally to the smooth hydrophilic channel region,where they continue to grow up until the final detachment.The opening of the smooth channel on Less tip surface is toward the surface center,and the closer to the center the wider the smooth channel.The cooling liquid can be quickly supplied to the micro-pillar area where bubbles are generated,meanwhile the abundant liquid inside the smooth channel can also promote the timely departure of large bubbles,which accordingly leads to the best boiling heat transfer per-formance on Less tip surface.The CHF value of all surfaces increase with liquid subcooling.The formation of vapor film at the bottom of vapor columns gravely impedes the fresh liquid supply to heat transfer surface,resulting in the local dryout and the trigger of CHF.
关键词
微柱阵列/楔形通道/混合润湿/强化换热/池沸腾Key words
micro-pillar array/wedge-shaped channel/mixed wettability/heat transfer enhance-ment/pool boiling引用本文复制引用
出版年
2024
NETL
NSTL
万方数据