室温硫化硅橡胶涂料因其可靠性较高、具有良好的憎水性和憎水迁移性等性能，能够较好地抑制污闪现象。但在某些特殊的运行环境下，RTV涂料也可能会出现脱落、快速失效等状况，无法再抑制设备的污闪。近年来，在某处于酒厂环境下的换流站内，电气设备及绝缘子上的RTV涂层出现憎水性快速失效现象。本文首先选取了涂覆有多个厂家、多种配方RTV涂料的新绝缘子试样，并将其布置在包含某换流站在内的酒厂附近的多个地点，并进行长期的憎水性跟踪监测，探究RTV涂料憎水性变化情况与距酒厂距离、电场强度、涂料配方等因素的关系，并根据测量结果得到实地试样的使用寿命情况，发现各类试样均在一年内憎水性由HC1级下降至HC6级。后续，将长期老化后发生憎水性失效的试样取回，于实验室内测量其闪络电压情况，并与新试样进行对比。结果表明，其闪络电压下降超过20kV，已危害到该换流站的稳定运行。将长期老化后发生憎水性失效的试样置于实验室环境下，并定期对其进行憎水性恢复情况测量，发现长时间脱离酒厂环境下的试样憎水性未发生恢复；擦除其表面污秽，试样的憎水性恢复至HC3级，憎水性迁移性也得到恢复。为进一步确定酒厂环境中造成RTV涂料憎水性失效的主要物质，以及涂料种类对其抗失效性能的影响，本文选取了脱醇型RTV、脱肟型RTV、防腐漆、HTV四种种类涂料，并选取去离子水、无水乙醇、酒厂原浆三种物质模拟气体环境，采用热加湿、无雾加湿、超声波加湿三种老化方式，搭建模拟老化平台进行老化。结果表明：仅以酒厂原浆作为老化因子，通过热加湿和超声波加湿的试样会发生憎水性失效，其中HTV下降最严重，而脱醇型RTV下降最弱；涂料厚度对憎水性下降情况无影响。后续，通过红外光谱、XPS元素分析、液相色谱、扫描电镜等多种分析手段确定有机污秽具体成分，并设计试验探究其作用的微观机理。结果表明：有机污秽内含有大量羟基，其主要成分为蔗糖-6-乙酸酯及邻苯二甲酸二壬酯等有机物；污秽通过液滴转移至涂料表面并留存，影响小分子硅氧烷侧链有序取向，从而使试样丧失憎水性；污秽的存在会一定程度上加速涂料内部填料的析出，但在憎水性快速失效的过程中，涂料表面憎水性情况与涂料内部老化情况并无直接相关性。结合污秽成分及其作用机理，本文提出了相关问题的解决方法并分析了现场污秽来源。
Room Temperature Vulcanized Silicone Rubber (RTV) coating can better suppress pollution flashover due to its high reliability, good hydrophobicity and hydrophobic migration properties. However, in some special operating environments, RTV coatings may fall off and fail rapidly, and can no longer suppress pollution flashover from equipment. In recent years, in a converter station located in a winery environment, hydrophobic and rapid failure of RTV coatings on electrical equipment and insulators occurred. Study the reasons for this phenomenon, find out the main contamination causing this phenomenon, its sources and mechanisms, evaluate the hydrophobicity of RTV coatings in this environment, and propose ways to improve this problem, which will help maintain the converter station and the stable operation of the local power grid.This article first selected new insulator samples coated with RTV coatings from multiple manufacturers and multiple formulas, and arranged them in multiple locations near a winery including a certain converter station, and conducted long-term hydrophobicity tracking and monitoring, to explore the relationship between the changes in hydrophobicity of RTV coatings and factors such as distance from the winery, electric field strength, coating formula, and obtain the service life of field samples based on the measurement results. It was found that the hydrophobicity of all types of samples dropped from HC1 level within one year to HC6 level. Subsequently, the samples that had hydrophobicity failure after long-term aging were retrieved, their flashover voltages were measured in the laboratory, and compared with new samples. The results show that the flashover voltage dropped by more than 20kV, which has endangered the stable operation of the converter station. The samples that had hydrophobicity failure after long-term aging were placed in a laboratory environment, and their hydrophobicity recovery was measured regularly. It was found that the hydrophobicity of the samples that had been away from the winery environment for a long time did not recover; wipe away the contamination on their surfaces, The hydrophobicity of the sample was restored to HC3 level, and the hydrophobic migration was also restored.In order to further determine the main substances that cause the hydrophobic failure of RTV coatings in the winery environment, and the impact of coating types on their failure resistance, this article selects four types of coatings, three substances to simulate the gas environment, and uses three types of aging method, and builds a simulated aging platform for aging. The results show that using only the distillery puree as the aging factor, the samples humidified by thermal humidification and ultrasonic wave will experience hydrophobicity failure, in which the HTV decreases the most, while the dealcoholization type RTV decreases the weakest; the coating thickness has no effect on the hydrophobicity decrease.Subsequently, various analytical methods such as infrared spectroscopy, XPS elemental analysis, liquid chromatography, and scanning electron microscopy were used to determine the specific components of organic pollution, and experiments were designed to explore the microscopic mechanism of its action. The results show that organic pollution contains a large number of hydroxyl groups, and its main components are organic compounds such as sucrose-6-acetate and dinonyl phthalate; the pollution is transferred to the coating surface through droplets and remains, affecting the small molecule silicone side. The chains are oriented in an orderly manner, causing the sample to lose its hydrophobicity; the presence of contamination will accelerate the precipitation of fillers inside the paint to a certain extent, but in the process of rapid hydrophobicity failure, the hydrophobicity of the paint surface is not directly related to the internal aging of the paint. Combining the pollution components and their mechanisms of action, this article proposes solutions to related problems and analyzes the sources of on-site pollution. The surface contamination of RTV samples in a certain converter station mainly comes from three links in the brewing process of the winery: high-temperature distillation, opening and canning, and drying of lees. By pre-coating RTV samples with contaminant after hydrophobicity migration, or increasing the horizontal inclination angle of the sample during operation, the declining rate in hydrophobicity can be effectively slowed down.
