| 摘要: |
| 本文制作了微机械加工的阵列方微柱金属表面，实验研究了其在环境温度Tatm=24 ℃，相对湿度RH=17%，不同冷表面温度（Tw=﹣5.2、﹣10.1、﹣15.2 ℃）及不同试件尺寸时，自然对流条件下的结霜特性，分析了表面温度和持续时间对霜层厚度和霜重量的影响，提出了阵列方微柱表面的抗结霜机理，并通过仿真模拟进行了验证。结果表明：当冷表面温度为﹣10 ℃时，阵列方微柱表面的霜层质量比平表面降低了约32%；自然对流使微柱之间产生了空气涡旋，水蒸气会随着空气涡旋流动而无法在凹槽内停留，霜仅形成在微柱顶部，凹槽内不结霜，从而显著减少了有效结霜面积；当微柱间距L过大时，凹槽内会形成冷凝液滴并结霜。 |
| 关键词: 结霜特性 阵列方微柱表面 自然对流 仿真模拟 |
| DOI： |
| 投稿时间：2020-07-07 修订日期：2020-11-06
|
| 基金项目:国家博士后创新计划（BX201700166）资助项目。 |
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| Frosting Characteristics of Horizontal Array Square Micropillar Surface under Natural Convection |
|
Zhang Tianlei, Zhao Yanjie
|
| (School of Mechanical Engineering, Tianjin University) |
| Abstract: |
| In this study, a micromachined array square micropillar metal surface was fabricated. Its frosting characteristics under natural convection were investigated experimentally at an ambient temperature of Tatm= 24 ℃ and relative humidity of 17%, with different cold surface temperatures Tw of ﹣5.2 ℃, ﹣10.1 ℃, and﹣15.2 ℃ and different specimen sizes. The effects of the surface temperature and time duration on the frost thickness and weight were analyzed. In addition, an antifrosting mechanism of the array square micropillar surface was proposed and validated by simulation. The results showed that when the surface temperature was -10 °C, the frost weight on the array square micropillar surface reduced by approximately 32% compared to that on a flat surface. Moreover, an air vortex was generated by natural convection, which prevented the water vapor from remaining in the groove. Frost formedonly on the top of the micropillar, rather than in the groove. The effective frosting surface was reduced significantly. When the micropillar spacing was too large, condensation droplets and frost were formed inside the groove. |
| Key words: frosting characteristics array square micropillar surface natural convection simulation |
