• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2017, Vol. 53 ›› Issue (6): 158-165.doi: 10.3901/JME.2017.06.158

• 可再生能源与工程热物理 • 上一篇    下一篇

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微结构表面喷雾冷却性能试验研究

刘妮, 李丽荣, 钟泽民   

  1. 上海理工大学能源与动力工程学院 上海 200093
  • 出版日期:2017-03-20 发布日期:2017-03-20
  • 作者简介:刘妮,女,1974年出生,博士,副教授。主要研究方向为制冷空调新技术。E-mail:liu_ni@163.com

Heat Transfer Characteristics of Spray Cooling on#br# Micro-structured Surface

LIU Ni, LI Lirong, ZHONG Zemin   

  1. School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093
  • Online:2017-03-20 Published:2017-03-20

摘要:

搭建一套封闭式喷雾冷却试验系统,使用水作为冷却工质,结合高速摄像仪对试验进行可视化研究,分析对比光滑表面和微结构表面喷雾冷却换热特性。结果发现,相比光滑表面,不同几何形貌的微结构表面都能提高喷雾冷却的换热能力,其中换热最好的是方形肋表面,直肋表面次之,扇形肋表面较差,但均优于光滑表面。微结构表面的润湿性强于光滑表面,微结构的存在能够提高喷雾冷却热流密度,使喷雾冷却提前进入两相区,避免了沸腾的滞后性。不同形式的微结构表面表现出不同的换热效果,主要是因为微结构表面对换热的强化不仅和面积增幅有关,还与微槽的紧密程度和排列方式有关。此外,试验中发现喷雾冷却存在温度不均匀现象,且微结构表面温度不均匀性大于光滑表面,但是降低系统压力,这种温度不均匀性可以得到明显改善。

关键词: CHF, 微结构表面, 温度不均匀性, 喷雾冷却

Abstract:

Experiments are conducted to study the heat transfer characteristics of micro-structure and flat surface in spray cooling. The micro-structured surfaces including square pin fins, straight rectangular fins and fan fins along with a referenced flat surface are tested in a closed loop system with water as the working fluid. The experimental results indicate that the fin arrangement rather than a simple increased wetted area plays significant role on the spray cooling performance of the micro-structure surface. Using a flat surface as reference, the micro-structured surface produced more or less enhancement in spray cooling than the flat surface. The micro-structure is indicated can improve the heat flux, acquired higher CHF. In addition, to improve heat transfer, the micro-structure surface provides other advantages such as reducing the time of transition to two phase regime. And the micro-structure surface with square pin fins outperformed the surface with straight rectangular fins and fan fins. However, there exists a relative more serious temperature non-uniformity phenomenon on the enhanced surface than flat surface, and it can be improved by reducing the system pressure.

Key words: CHF, micro-structure surface, temperature non-uniformity, spray cooling