| 摘要: |
| 本文对空气源热泵的翅片管换热器表面霜层生长特性进行实验研究,通过红外热像仪对霜层表面温度进行测量,并用热电偶直接测量装置进行校核。分析了平片,波纹片,条缝片3种翅片类型及翅片节距对霜层厚度、结霜量、换热量的影响,并用霜层-湿空气界面条件等作为传热及传质驱动力分析了霜层生长规律。实验结果表明,波纹片及条缝片翅片换热器界面传热、.传 质驱动力高于平片,造成其表面霜层生长速度大于平片,而在结霜后期条缝片霜层生长速度显著加快;在3种翅片中,条缝片表 面结霜周期最短,而平片表面结霜周期最长;波纹片换热器的平均换热量最大,比条缝片、平片换热器分别高出0.61%，2.67%；翅片节距对界面传热.传质驱动力的影响较弱,但翅片节距越大,其表面霜层厚度增长越快且结霜周期越长,大节距翅片换热器 表面霜层较为疏松。综合考虑结霜-除霜周期中换热器平均换热量及空气侧阻力,结霜工况下波纹片换热器最佳翅片节距约为2.2 m。 |
| 关键词: 空气源热泵 翅片类型 翅片节距 霜层表面温度 |
| DOI： |
| 投稿时间：2020-09-19 修订日期：2021-01-19
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| 基金项目:国家自然科学基金(51176142)资助项目。 |
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| Experimental Study on Effect of Fin Structure on Frosting Characteristics of Finned Tube Heat Exchangers |
| Xie Fulin,Guo Xianmin,Guo Xinwei,Xue Jie |
| (Tianjin Key Laboratory of Refrigeration Technology，Tianjin University of Commerce ;ZVISION Technologies Co.，Ltd .) |
| Abstract: |
| In this study, the surface temperature of the frost layer was measured using an infrared thermal imager and calibrated using direct measurements from a micrometer and thermocouple device. The growth characteristics of the frost layer on the surface of the finned-tube heat exchanger were experimentally studied. The effects of fin type and fin pitch on the frost thickness, frost mass, and heat transfer capacity were analyzed. The frost growth characteristics were analyzed by considering the condition at the frost wet air interface as the driving force of heat and mass transfer. The experimental results indicated that the driving force of heat and mass transfer at the interface of the wavy fin and the split fin heat exchangers is higher than that of the flat fin, resulting in higher growth rates of the frost layer on the wavy and split fins than that on the flat fin. In the late frosting period, the growth rate of the frost layer on the split fin was significantly accelerated. Among the three types of fins, the frosting duration on the split fin was the shortest and the longest on the flat fin. The average heat transfer capacity of the wavy fin heat exchanger during the frosting and defrosting periods was the largest, which was 0.61% and 2.67% higher than that of the split and flat fin heat exchangers, respectively. Meanwhile, the influence of the fin pitch on the driving force of heat and mass transfer at the interface is weak, and the larger the fin pitch is, the faster the frost layer thickness increases, and the longer the frosting duration is. Considering the average heat transfer capacity during the frosting defrosting period and the air flow resistance of the heat exchanger, the optimal fin pitch is approximately 2.2 mm under the frosting condition. |
| Key words: air source heat pump fin type fin pitch frost surface temperature |
