化工学报 ›› 2021, Vol. 72 ›› Issue (6): 3278-3287.DOI: 10.11949/0438-1157.20201427

• 流体力学与传递现象 • 上一篇    下一篇

时空调控微柱表面浸润性强化单气泡沸腾换热

陈宏霞(),李林涵,王逸然,郭宇翔,刘霖   

  1. 华北电力大学能源动力与机械工程学院,北京 102206
  • 收稿日期:2020-10-12 修回日期:2020-12-29 出版日期:2021-06-05 发布日期:2021-06-05
  • 通讯作者: 陈宏霞
  • 作者简介:陈宏霞(1980—),女,博士,副教授,hxchen@ncepu.edu.cn
  • 基金资助:
    2019年度预研教育部联合基金青年人才基金项目(6141A02033526);国家自然科学基金项目(51576063)

Enhancement of single bubble boiling heat transfer on micropillar surface by wettability modulation with time and space

CHEN Hongxia(),LI Linhan,WANG Yiran,GUO Yuxiang,LIU Lin   

  1. School of Energy, Power and Mechanical Engineering, North China Electric Power University, Beijing 102206, China
  • Received:2020-10-12 Revised:2020-12-29 Online:2021-06-05 Published:2021-06-05
  • Contact: CHEN Hongxia

摘要:

微结构耦合浸润性调控是目前强化核态沸腾换热的主要手段,针对水工质在单晶硅微柱表面的核态沸腾过程,采用CFD-VOF三维数值模拟方法,对比研究时间及空间分别调控表面浸润性对沸腾气泡动力学、相界面形变及传热性能的影响。结果表明:亲水性增强使得气泡界面曲率增大、合力增强,促使气泡的脱离;空间调控主要表现为增大气泡体积,时间调控则主要表现为优化气泡动力学过程,提高热流较大的生长阶段在整个气泡周期内的占比,从而强化换热;本实验工况下,空间梯度浸润表面以及在生长阶段提高壁面亲水性,均可大幅度提高单气泡沸腾换热性能,平均热流最大可提高42.7%;考虑微尺度下梯度浸润性加工难度,时间调控浸润性强化沸腾换热具有更好的发展前景。

关键词: 浸润性, 时空调控, 数值模拟, 核态沸腾, 气泡动力学

Abstract:

Microstructure coupled wettability control is currently the main method to enhance nucleate boiling heat transfer. In this work, the CFD-VOF three-dimensional numerical method is conducted to compare the influence of wettability modulation with time and space on bubble dynamics, phase interface deformation and heat transfer performance. The results show that the hydrophilicity increases the curvature and the resultant force at the bubble interface which promotes the departure of the bubble. Space modulation mainly increases the bubble volume, while the time modulation always optimizes the bubble dynamic and increases the proportion of the growth stage in the entire bubble cycle, leads to an obviously enhancement of heat transfer. Both the space gradient wettability modulation and the hydrophilicity improvement in growth stage can improve the heat transfer performance of single bubble boiling significantly, and the average heat flow increases by 42.7%. Considering the difficulty in manufacturing gradient wettability surfaces at micro-scale, time modulation wettability has a better development prospect in boiling heat transfer enhancement.

Key words: wettability, time and space modulation, numerical simulation, nucleate boiling, bubble dynamic

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