CIESC Journal ›› 2021, Vol. 72 ›› Issue (8): 4093-4103.DOI: 10.11949/0438-1157.20201903

• Fluid dynamics and transport phenomena • Previous Articles     Next Articles

Experimental study on flow boiling heat transfer on superhydrophobic/hydrophilic structure surface

Hongpeng JIANG(),Minli BAI(),Dongdong GAO,Linsong GAO,Jizu LYU   

  1. School of Energy and Power Engineering, Dalian University of Technology, Dalian 116024, Liaoning, China
  • Received:2020-12-23 Revised:2021-04-19 Online:2021-08-05 Published:2021-08-05
  • Contact: Minli BAI

超疏水/亲水性结构表面流动沸腾传热实验研究

姜洪鹏(),白敏丽(),高栋栋,高林松,吕继组   

  1. 大连理工大学能源与动力学院,辽宁 大连 116024
  • 通讯作者: 白敏丽
  • 作者简介:姜洪鹏(1995—),男,硕士研究生,jianghp1995@163.com
  • 基金资助:
    国家自然科学基金项目(51876027);中央高校基本科研业务费专项资金(DUT19JC09)

Abstract:

The laser ablation method is used to prepare four superhydrophobic/hydrophilic regular microarray structure surfaces on the polished copper without coating modification. In this work, visualization and temperature processing calculations were applied to analyze the effects of surface wettability and subcooling on flow boiling heat transfer performance, then the active nucleation site density between experimental data and predicted value were compared. The results show that the hydrophobic surface has a negative effect on single-phase flow heat transfer and presents an outstanding heat transfer coefficient (HTC) by 75.5% compared with the bare copper surface. Simultaneously, it has an early appearance of onset of nucleate by 3.5 K, and the number of nucleation sites was increased by more than 5 times compared with the bare copper surface, but has a lower critical heat flux. The super hydrophilic surface could enhance the single-phase flow heat transfer and slightly increased the flow boiling heat transfer. Comparing the bubble growth process on the hydrophilic and hydrophobic surface, the bubbles at the end of the hydrophobic surface were easy to coalesce and the growth period was longer, while the growth period of bubbles on the hydrophilic surface was shorter, and no obvious bubble coalescence occurred.

Key words: microscale, gas-liquid flow, heat transfer, superhydrophobic, superhydrophilic

摘要:

用激光烧蚀方法在抛光后的铜上制备出四种无需涂覆修饰即可获得超疏水/亲水性的规则微阵列结构表面。基于流动可视化与温度数据结果,分析了表面浸润性和过冷度对流动沸腾传热性能的影响,与经典汽化核心密度关联式进行了对比。结果表明:疏水表面可削弱单相对流传热,大幅强化沸腾传热,最大传热系数提高了75.5%,沸腾起始点提前3.5 K,且汽化核心数目较裸铜表面提高了5倍以上,但有较低的临界热通量。超亲水表面可增强单相对流传热、小幅度提升流动沸腾传热。对比亲水表面与疏水表面的气泡生长过程,发现疏水表面尾端气泡容易汇聚,生长周期较长;而亲水表面没有发生明显的气泡汇聚行为,气泡生长周期较短。

关键词: 微尺度, 气液两相流, 传热, 超疏水, 超亲水

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