【作者】 赵玉顺；

【导师】 李剑；

【作者基本信息】 重庆大学 ， 电气工程， 2010， 博士

【摘要】 由于冻雨、湿雪、霜冻等原因导致的输电线路覆冰,是影响电力系统安全的主要问题之一。输电线路覆冰,通常可导致线路停电、断线、倒塔、导线舞动、绝缘子闪络等事故,从而产生巨大的经济损失。因此,输电线路防冰与除冰技术研究具有重要的学术意义与应用价值。本文研究了一种新的绝缘子超疏水涂层制备方法,测量并分析了绝缘子超疏水涂层的疏水特性,通过覆冰实验研究了绝缘子超疏水涂层的防冰特性。论文的主要内容有:①通过分析超疏水涂层润湿理论,对防冰超疏水涂层需具备的表面微结构和化学成分进行研究,提出了一种能够在具有大面积、复杂外形基体上制备超疏水涂层的方法,即纳米粒子表面自组装法;利用纳米粒子表面自组装法制备出改性纳米二氧化硅超疏水涂层,并对超疏水涂层的表面微结构、化学成分和憎水性进行分析,证明纳米粒子表面自组装法能够制备出二元微纳粗糙结构,分析并说明了改性纳米二氧化硅超疏水涂层的缺陷和制备方法的不足。②提出了在纳米二氧化硅自组装体与基体之间引入聚二甲基硅氧烷(Polydimethylsiloxane, PDMS)过渡层的方法,解决了改性纳米二氧化硅超疏水涂层的表面固化龟裂问题,制备出PDMS/纳米二氧化硅杂化超疏水涂层,并对PDMS/纳米二氧化硅杂化超疏水涂层的表面微观结构、化学成分、酸碱耐受性及其疏水稳定性进行研究,进一步通过试验研究了PDMS/纳米二氧化硅杂化超疏水涂层的基本绝缘性能,重点研究了涂覆PDMS/纳米二氧化硅杂化超疏水涂层的绝缘子的淋雨闪络特性。③提出了一种测量超疏水涂层的过冷却水滴捕获率的试验方法,采用该方法成功测量出PDMS/纳米二氧化硅杂化超疏水涂层的过冷却水滴捕获率;研究了覆冰温度与涂层倾斜角度对PDMS/纳米二氧化硅杂化超疏水涂层覆冰过冷却水滴捕获率的影响,分析了PDMS/纳米二氧化硅杂化超疏水涂层过冷却水滴捕获率随覆冰进程的演变。研究结果表明,PDMS/纳米二氧化硅杂化超疏水涂层具有非常小的过冷却水滴捕获率。④研究了超疏水涂层覆冰粘结强度,设计出覆冰粘结强度测量装置,采用万能力学试验机测试了PDMS/纳米二氧化硅杂化超疏水涂层的垂直覆冰粘结强度和剪切覆冰粘结强度,测试结果表明,PDMS/纳米二氧化硅杂化超疏水涂层具有非常小的覆冰粘结强度。通过研究覆冰与PDMS/纳米二氧化硅杂化超疏水涂层的复合接触面的微观结构,分析了超疏水涂层具有微小覆冰粘结强度的原因;并且,对脱冰后的PDMS/纳米二氧化硅杂化超疏水涂层进行的微观形貌与憎水性进行了分析与测试,结果表明脱冰过程不会破坏该涂层的表面微观结构与超疏水性。⑤分别在人工气候室和自然环境中对PDMS/纳米二氧化硅杂化超疏水涂层的防冰性能进行实验研究。通过对涂覆PDMS/纳米二氧化硅杂化超疏水涂层的绝缘子的覆冰形貌、覆冰重量以及覆冰闪络电压的试验研究与分析,证明了PDMS/纳米二氧化硅杂化超疏水涂层具备延缓覆冰与减小覆冰量的能力,涂覆超疏水涂层的绝缘子在覆冰过程中具有较高的绝缘强度,过冷却水滴持续或长时间的冲刷以及覆冰粘结不会破坏涂层的超疏水特性。上述研究过表明,纳米粒子表面自组装法能够制备出疏水性能稳定的PDMS/纳米二氧化硅杂化超疏水涂层,该涂层具备了输电线路防冰的能力,并在人工气候室与现场自然环境覆冰实验中显示出良好的防冰效果。更多还原

【Abstract】 Ice accumulation on transmission lines, caused by freezing rain, wet snow or frost, is one of major problems influencing safety of electric power system. Ice accumulation may lead to outage, conductor break, tower collapse, conductor galloping, and insulator flashover of transmission lines, which can lead to great economic losses. Therefore, research on the anti-icing and de-icing of transmission lines has great academic significance and application value. The dissertation presents the preparation, hydrophobicity, and anti-icing performances of a new type of superhydrophobic coating.The work focuses mainly on the following contents:①The microstructure and chemical components, required for superhydrophobic coatings, was studied through analyzing the wetting theory of superhydrophobic coatings. A simple approach, named as the surface self-assemble of nano-particles (SSNP), was proposed to prepare superhydrophobic coatings economically on substrates with large surface area and complicate shapes. A nano-silica superhydrophobic coating was prepared by the approach and its surface microstructure, chemical component, and hydrophobicity were investigated. The research results show that a dual micro- and nano-scale hierarchical structure was fabricated on the nano-silica super-hydrophobic coating by the SSNP. Several drawbacks of the nano-silica super-hydrophobic coating were also presented.②An improved approach to insert a Polydimethylsiloxane (PDMS) transition layer between nano-silica self-assemblies and substrates was proposed to prevent cracks of curing surface of the nano-silica superhydrophobic coating. A PDMS/nano-silica hybrid superhydrophobic coating was prepared by the improved approach. Microstructure, chemical components, and hydrophobicity stability of the PDMS/nano-silica hybrid superhydrophobic coating were investigated.③An experimental method was proposed to measure the super-cooled water droplet capture rate of the superhydrophobic coating. The experimental method was used to measure the super-cooled water droplet capture rate of the PDMS/nano-silica hybrid superhydrophobic coating. The influences of the icing temperature and surface inclined angle to the super-cooled water droplet capture rate were investigated. The change of the super-cooled water droplet capture rate of the PDMS/nano-silica hybrid superhydrophobic coating was also investigated during the ice accumulation. The results show that the PDMS/nano-silica hybrid superhydrophobic coating possesses a very small super-cooled water droplet capture rate.④Ice adhesion strength of the superhydrophobic coating was investigated. Testing devices to measure ice adhesion strength of the superhydrophobic coating were designed. The vertical and shearing forces of ice adhesion to the PDMS/nano-silica hybrid superhydrophobic coating were measured through the approach. Testing results show that the superhydrophobic coating possesses very small ice adhesion strength. The analysis to microstructure of the interface between ice layer and the superhydrophobic coating show the reasons why the very small ice adhesion strength exists on the superhydrophobic coating. Furthermore, the microstructure and hydrophobicity of the PDMS/nano-silica hybrid superhydrophobic coating were measured and analyzed. The results show that shedding influences little on the surface microstructure and hydrophobicity of the superhydrophobic coating⑤Ice accumulation experiments both in laboratory and in filed were carried out to investigate the ice accumulation properties on insulator strings coated with the PDMS/nano-silica hybrid superhydrophobic coating. Morphology and weight of the accumulated ice on the coated insulator strings were both studied. Flashover testes were also carried out on the coated insulator strings. The results show that the ice accumulation on insulators is inhibited and reduced by the superhydrophobic coating.The insulator strings with the superhydrophobic coating possesses very high insulation strength. And the hydrophobicity of the superhydrophobic coating was influenced slightly by impact of the super-cooled rain and shedding of ice.The above results revealed that the PDMS/nano-silica hybrid superhydrophobic coating was prepared through the SSNP method. The PDMS/nano-silica hybrid superhydrophobic coating is capable of anti-icing for transmission lines. The experimental results in both laboratory and filed show the good anti-icing properties of the superhydrophobic coating.更多还原