吸水性涂层在霜层生长初期的抑霜

研究吸水性涂层对霜层生长过程的影响,以寻求抑制结霜的有效方法.通过自行设计的试验设备对吸水性涂层表面上霜层生长特性进行试验研究,获取了不同时段霜层的显微图片,采用数字图像处理方法对其分析,与无涂层的铜表面进行对比.结果表明,吸水性涂层使得结霜时间推迟,霜层高度下降,冰晶体分布稀疏.此外霜层生长初期冰晶体的结构发生了变化,晶体呈倒立状,在某个时段内持续这种状态.对列固含率的分析表明,吸水性涂层的表面在初期有些位置冰晶体含量较高,但有些位置则接近于零,这样的霜层在生长初期甚至加强了热传递.最后通过对比不同表面霜层高度随时间的变化规律发现:吸水性涂层在初期抑霜效果最好,随着时间的推移其抑霜能力逐渐下降.

Restrained frost effect of hydrophilic coating at initial stages of frost formation

The hydrophilic coating effect on frost growth was studied in searching an effective method to restrain the frost formation.Characteristics of frost formation on hydrophilic surface were studied,the microscopical picture of frost was described,and digital image processing technique was used to analyze the distribution of ice crystal in frost layer.The results indicate that hydrophilic coating restrains frost formation and reduces the frost height and the ice crystal quantity.Furthermore,the structure of ice crystal is changed at initial stages of frost formation,and the ice crystals stand upside down at this period.The analysis on column occupancy rate indicates that the distribution of initial ice crystal occupancy rate on hydrophilic surface is not uniform;such frost even enhances the heat transfer.Finally,by comparing the frost heights on different surfaces it is found that the restrained frost ability of hydrophilic coating decreases with time.