摘要
制备了具有不同疏水区宽度和面积分率的疏水-亲水间隔规则排列的组合表面。观测常压蒸汽在组合表面上冷凝时疏水区液滴的特性(液滴移除方式和最大液滴半径),利用格子Boltzmann方法模拟组合表面上凝液的运动。考察疏水区、亲水区宽度和表面过冷度对组合表面强化蒸汽冷凝传热的影响。利用滴状-膜状组合传热模型分析组合表面蒸汽冷凝传热性能的影响因素,并与实验结果比较。发现疏水区液滴自发地向亲水区定向迁移,精细设计的组合表面可以实现蒸汽滴状冷凝传热的强化,实验中强化因子可达1.20。疏水区宽度约为0.55 mm时组合表面的传热性能最大。表面过冷度越大,组合表面强化传热的效果越差,模型分析与实验结果吻合良好。
The hybrid surfaces with hydrophobic and hydrophilic regions arranged regularly and alternatively are prepared. Various widths and area fraction of the hydrophobic region are designed. The droplet properties （such as droplet drainage mode and maximum droplet radius） during steam condensation at atmospheric pressure are visualized. The motion process of condensate on hybrid surfaces is simulated by lattice Boltzmann method. The influences of the widths and surface subcooling of hydrophobic and hydrophilic region on enhancement of the steam condensation heat transfer of the hybrid surfaces are investigated. The influencing factors on the steam condensation heat transfer performance of hybrid surfaces are analyzed and calculated by hybrid condensation heat transfer model. The comparison between model and experimental results is also conducted. It is found that the droplet on the hydrophobic region can spontaneously migrate into the hydrophilic region. The dropwise condensation heat transfer of steam can be effectively enhanced by the finely designed hybrid surfaces. The enhancement factor of the heat transfer performance of the hybrid surface can approach to 1.20. When the width of the hydrophobic region is about 0.55 mm, the heat transfer performance of hybrid surface reaches the maximum. Furthermore, the effect of the heat transfer enhancement of hybrid surfaces decreases with the increase of surface subcooling. The comparison results indicate that the analytical （theoretical） results can well and conveniently predict the experimental results.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2015年第10期3826-3833,共8页
CIESC Journal
基金
国家自然科学基金项目(51236002)
高等学校博士学科点专项科研基金项目(20120041110018)~~
关键词
凝结
传热
格子BOLTZMANN模拟
表面
组合传热模型
传热强化
condensation
heat transfer
lattice Boltzmann simulation
surface
heat transfer model of hybrid surfaces
heat transfer enhancement
