【作者】 李自强；

【导师】 王鹏；

【作者基本信息】 华北电力大学 ， 工程硕士（专业学位）， 2021， 硕士

【摘要】 输电线路覆冰是指水分在输电线路上的冻结而结成冰霜的一种现象。作为国家举足轻重的生命线工程,输电线路的安全运行已经受到广泛重视。我国是世界上输电线路覆冰最严重的国家之一,开展防覆冰研究具有重要的意义。目前国内外研究者已经对超疏水材料在防覆冰方面的应用进行了许多探索,并发现具有纳米/微结构的超疏水表面可以促进水滴快速滚落,延缓冰成核,减少覆冰粘附力。但机械稳定性差已经成为阻碍超疏水材料实际应用的主要挑战;突出表现为:循环覆冰/除冰过程会破坏超疏水表面的微纳米结构,进而大大降低疏冰性。因此,制备出一种具有机械稳定性,疏冰稳定性高的低覆冰粘附力的涂层对目前的防覆冰涂层研究是非常有意义的。在本文中,设计了两种不同防冰策略的涂层,分别是采用被动防冰策略的极低覆冰粘附力超疏水网和主/被动防冰策略下光热/超疏水协同作用的防冰除冰网。在本文中二氧化硅纳米颗粒被半嵌入到商用聚酰胺网的微米尺度纤维中。聚酰胺网的面积分数可以通过改变聚酰胺网的目数来确定,以此来研究面积分数对冰粘接强度的贡献。一般情况下,冰的粘附强度随面积分数的降低而降低。制备得到的超疏水涂层最小覆冰粘附力可小至1.9 kPa,延迟冻结时间可长达1048s。此外,半嵌入结构和层级结构的结合,使超疏水涂层具有优异的机械稳定性,可承受20次覆冰/除冰循环,60次砂纸磨损循环和220℃的温度处理。因此,这种超疏水涂层在防结冰方面有很好的应用前景。尽管依靠被动防冰策略的超疏水涂层进行防冰被证明是有一些效果的,但单一种被动除冰策略面对情况复杂多变,环境恶劣尤其是长时间的雨雪天气时,超疏水涂层并不能一直保持其防冰/除冰效果。因此设计了一种同时具备主/被动防冰策略。该涂层应用光热主动除冰,超疏水被动防冰:一方面半嵌入的蜡烛灰赋予表面优异的光热特性,可通过阳光照射快速融化冰;另一方面,基于蜡烛灰的超疏水涂层具有优异的被动防冰性能,最小覆冰粘附力可小至3.0 kPa,延迟冻结时间可长达1096 s。在此基础之上,半嵌入式结构使得聚酰胺网上蜡烛灰涂层具有出色的机械稳定性,可以耐砂纸打磨,并且超疏水表面具有优异的自清洁性能。这种主动与被动防冰策略的结合为目前输电线路的防冰除冰方法提供了一种参考思路。更多还原

【Abstract】 Transmission line icing refers to the phenomenon that water freezes on the transmission line and forms frost.As a vital lifeline project in China,the safe operation of transmission lines has received extensive attention.China is one of the countries with the most serious icing on transmission lines in the world,and it is of great significance to carry out anti-icing research.At present,researchers in China and abroad have carried out many explorations on the application of superhydrophobic materials in anti-icing,and found that the superhydrophobic surface with nano/microstructure can promote the rapid rolling of water droplets,delay ice nucleation,and reduce ice adhesion.However,poor mechanical stability has become a major challenge to hinder the practical application of superhydrophobic materials.The outstanding performance is that the cyclic icing/de-icing process destroys the micro/nano structure of the superhydrophobic surface,thereby greatly reducing the ice hydrophobicity.Therefore,the preparation of a low icing adhesion coating with mechanical stability and high icing stability is very meaningful for the current research of anti-icing coating.In this paper,two coatings with different anti-icing strategies were designed,namely,the ultra-low icing adhesion superhydrophobic network with passive anti-icing strategy and the antiicing and de-icing network with light / superhydrophobic synergistic effect under active/ passive anti-icing strategy.In this paper,we tried to semi-embedded silica nanoparticles into the micron-scale fibers of commercial polyamide networks.The area fraction of polyester mesh can be determined by changing the mesh number of polyamide mesh.The contribution of area fraction to ice bonding strength was studied.In general,the adhesion strength of ice decreases with the decrease of area fraction.The minimum icing adhesion of the prepared super-hydrophobic network can be as small as 1.9kPa,and the delayed freezing time can be as long as 1048 s.In addition,the combination of semi-embedded structure and hierarchical structure makes the super-hydrophobic network have excellent mechanical stability,which can withstand 20 icing/de-icing cycles,60 sandpaper wear cycles and 220°C temperature treatment.Therefore,this super hydrophobic network has a good application prospect in anti icing.Although the superhydrophobic coating based on passive anti-icing strategy has been proved to have some effect on anti-icing,the single passive de-icing strategy cannot always maintain its anti-icing/de-icing effect in the face of complex and changeable conditions,especially in the long rain and snow weather.Therefore,an active / passive anti-icing strategy is designed.In this strategy,photothermal active deicing was applied,and ultra-low icing adhesion superhydrophobic coating was used as passive anti-icing.On the one hand,candle ash endowed the surface with excellent photothermal properties,which could rapidly melt ice through sunlight irradiation.On the other hand,the super-hydrophobic network based on candle ash has excellent passive anti-icing performance.The minimum icing adhesion force can be as small as3.0 kPa,and the delayed freezing time can be as long as 1096 s.On this basis,the semiembedded structure makes the polyamide online candle ash coating have excellent mechanical stability,can resist sandpaper grinding,and superhydrophobic surface has excellent self-cleaning performance.This combination of active and passive anti-icing strategies provides a reference for the current anti-icing and de-icing methods of transmission lines.更多还原