Effect of fin types of outdoor fan-supplied finned-tube heat exchanger on periodic frosting and defrosting performance of a residential air-source heat pump
Effect of fin types of outdoor fan-supplied finned-tube heat exchanger on periodic frosting and defrosting performance of a residential air-source heat pump
复制标题
室外风机翅片管换热器翅片类型对住宅空气源热泵周期性结霜和除霜性能的影响
DOI：
10.1016/j.applthermaleng.2013.11.052
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发表时间：
2014-08-01
影响因子：
6.4
通讯作者：
Yi, De-Bo
中科院分区：
文献类型：
--
作者：
Huang, Dong;Zhao, Ri-Jing;Yi, De-Bo
实验比较了平翅片、波纹翅片和百叶窗翅片对户式空气源热泵周期性结霜和除霜性能的影响。由于相同的除霜控制方案，每种翅片类型连续进行了6次结霜/除霜循环，结霜/除霜持续时间几乎相等，每种翅片类型的结霜/除霜持续时间分别约为46.6min和3.9min。利用第三、第四和第五次结霜/除霜循环的时间平均值比较了三种翅片的整体结霜/除霜性能，并对第四次循环的实时数据进行了分析，以比较它们的动态特性。实验结果表明，在空气源热泵系统中，平翅片的热力性能最好，其次是波纹翅片和百叶窗翅片。与百叶窗翅片相比，平翅片在结霜循环中的时均热容量、COP和输入功率分别提高了17.1%、9.0%和7.6%。平翅片的结霜曲线先略有增大后逐渐减小，而波纹翅片和百叶翅片的结霜曲线先略有增大，然后迅速减小，最后逐渐减小。同时，百叶窗翅片的曲线下降时间明显早于波纹翅片。结霜曲线的最初增加归因于表面粗糙度增加的正结霜效应超过了霜层热阻增加和结霜堵塞导致的风机送风量降低的负结霜效应。波浪型和百叶片型的结霜曲线由于室外轴流风机经历了结霜较多、风压降较大的失速区，结霜曲线迅速下降，失速区通过后略有下降。在46.6min的结霜时间内，由于室外轴流风机没有出现失速区，平翅片的结霜曲线始终略有下降。磨砂翅片管换热器应与风机特性耦合在一起进行优化设计。(C)2013爱思唯尔有限公司。保留所有权利。
The effect of fin types-flat, wavy and louver fins-of outdoor fan-supplied heat exchanger on the periodic frosting and defrosting performance of a residential air-source heat pump was experimentally compared. Six consecutive frosting/defrosting cycles were performed for each fin type, and the frosting/defrosting durations were almost equal, about 46.6 min and 3.9 min for each fin type, due to the same defrosting control schemes. The time-average values during the third, fourth and fifth frosting/defrosting cycles were used to compare the overall frosting/defrosting performance among three fin types, and the real-time data during the fourth cycle were analyzed to compare their dynamic characteristics. The experimental results showed the flat fin had the best thermal performance of the air-source heat pump, followed by wavy and louver fins. The time-average heating capacity, COP and input power for flat fin during frosting cycle were more by 17.1%, 9.0% and 7.6%, respectively than those for louver fin. The frosting curves for flat fin increased slightly and then decreased gradually, while the curves for wavy and louver fin types increased slightly at first, then decreased rapidly and gradually at last. Meanwhile, the curves for louver fin decreased considerably earlier than those for wavy fin. The initial increases of the frosting curves were ascribed to that the positive frost effect of increased surface roughness surpassed both the negative frost effects of increased frost layer thermal resistance and reduced fan-supplied airflow rate due to frost blockage. The frosting curves for wavy and louver fin types decreased rapidly because the outdoor axial fan experienced the stall zone caused by more frost accumulation and greater air pressure drop, and decreased slightly at last after the stall zone was went through. The frosting curves for flat fin decreased always slightly because the outdoor axial fan did not experience the stall zone during the frosting duration of 46.6 min. The frosted finned-tube heat exchanger and fan characteristic should be coupled together for the optimal design. (C) 2013 Elsevier Ltd. All rights reserved.