| 摘要: |
| 结霜是制约微通道换热器在制冷及空调系统应用的主要因素之一。针对微通道换热器结霜问题，本文基于相变驱动力分析了结霜机理，观察了不同环境因素下冷表面霜层生长形貌，并实验研究了湿空气温度、含湿量、气流速度及冷却液温度对微通道换热器结霜特性及换热性能的影响。结果表明：湿空气含湿量及气流速度是影响微通道换热器结霜的主要因素，结霜时间为15 min，含湿量为5.75 g/（kg干空气）工况下，换热器表面结霜量比含湿量为3.58 g/（kg干空气）时提高了63.87%；气流速度为2.5 m/s工况下，换热器表面结霜量比气流速度为1 m/s时增加了55.4%。随着结霜时间的增长，湿空气温度、冷却液温度越低，含湿量、气流速度越大，换热量下降趋势越明显。 |
| 关键词: 结霜 换热器 相变驱动力 换热量 形貌 |
| DOI： |
| 投稿时间：2020-05-11 修订日期：2020-09-15
|
| 基金项目:河南省自然科学基金（No.162300410112） |
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| Experimental Research on Frosting Characteristics and Heat Transfer Performance of Microchannel Heat Exchanger |
| Sheng Wei,Fang Yongqiang,Lan Qingyun,Hao Xiaoru |
| (School of Mechanical and Power Engineering, Henan Polytechnic University;Hami Henan New Energy Industry Research Institute) |
| Abstract: |
| Frosting is one of the main factors restricting the application of microchannel heat exchangers in refrigeration and air conditioning systems. Aiming at the frosting problem of a microchannel heat exchanger, the frosting mechanism was analyzed based on the phase transformation driving force, and the growth morphology of the frost layer on the cold surface under different environmental factors was observed in this study. The effects of wet air temperature, humidity ratio, air velocity, and coolant temperature on the frosting characteristics, and the heat transfer performance of the microchannel heat exchanger were experimentally studied. The results show that the humidity ratio and air velocity of the wet air are the main factors affecting the frosting of the microchannel heat exchanger. At 15 min of frosting, the amount of frost on the heat exchanger surface under a humidity ratio of 5.75 g/(kg dry air) increased by 63.87% compared with a humidity ratio of 3.58 g/(kg dry air); the amount of frost on the heat exchanger surface under an air velocity of 2.5 m/s increased by 55.4% compared to the air velocity of 1 m/s. With the increase in frosting time, the lower the temperatures of the humid air and coolant, the greater the humidity ratio and air velocity are, and the more obvious the downward trend of the heat exchange capacity is. |
| Key words: frost heat exchanger phase transformation driving force heat exchange capacity morphology |
