翅片表面涂层对结化霜除灰特性的影响

Effect of Fin Coating on Dust Removal via a Frosting-Defrosting Process

为了解决空调换热器长时间运行后性能下降的问题,需要及时清除换热器翅片上沉积的粉尘。本文提出采用空调换热器自身的结化霜过程来实现除灰,并实验研究了不同翅片表面涂层对结化霜除灰效果的影响。为了对比不同翅片表面涂层的除灰效果,采用4种实验样件,包括空调换热器常用的无涂层铝片和无涂层铜片,以及通过微纳结构自组装方法制备的具有不同表面润湿性的带亲水涂层铜片和带疏水涂层铜片。通过搭建可视化实验台观测了不同样件表面的结化霜除灰过程,对比了不同样件的除灰速率与残留灰量。实验结霜工况为:样件表面温度-10℃,结霜时间1 h,环境温度27℃,相对湿度50%;化霜工况下样件表面温度为5℃。实验结果表明:带有疏水涂层的铜片在结化霜过程中的除灰效果最好,疏水样件上残留粉尘的质量仅是无涂层铝片上残留粉尘质量的1.9%,是无涂层铜片上残留粉尘质量的2.0%,是亲水铜片上残留粉尘质量的5.9%。

To avoid deterioration in the performance of air conditioner heat exchangers after prolonged operation,the dust deposited on the fin surfaces should be removed in a timely manner.In this paper,the frosting-defrosting process of heat exchangers was used to realize the dust removal,and the effect of fin surface coatings on dust removal process was experimentally evaluated.Four test samples,including an uncoated aluminum plate,an uncoated copper plate,a hydrophilic copper plate,and a hydrophobic copper plate,were evaluated in the experiment.The hydrophilic copper plate and hydrophobic copper plate were prepared via a self-assembly method.A visual experimental apparatus was fabricated to observe the dust removal on various samples via the frosting-defrosting process.The dust removal rate and remnant dust weight were obtained.The frosting condition involves a surface temperature of-10℃,frosting time of 1 h,air temperature of 27℃,and relative air humidity of 50%.Furthermore,the defrosting condition corresponds to a surface temperature of 5℃.The dust removal on the hydrophobic surface exhibits the best performance when compared to other samples.The remnant dust weight on the hydrophobic surface is only 1.9%of that on the aluminum surface,2.0%of that on the copper surface,and 5.9%of that on the hydrophilic surface.