变压器防腐涂层导热性能提升技术研究

 以水性环氧富锌涂层为研究对象，通过向其中添加石墨烯、碳纳米管、碳纳米角和超细石墨粉混合物来改性变压器防腐涂层导热性能。通过瞬态板式热源法、红外热像仪、热阻测试仪和扫描电子显微镜对传统溶剂型涂层、水性环氧富锌涂层以及改性高导热涂层的导热性能和微观结构进行了分析。结果显示改性高导热涂层的热阻最小（2.51℃/W），导热系数最高（1.3450 W/（m·K）），表明其导热性能明显优于传统溶剂型涂层（4.57℃/W）和水性环氧富锌涂层（4.28℃/W）。改性高导热涂料导热性能的提高主要与其导热方式的优化和涂层致密性的提高有关。传统溶剂型涂料主要以声子形式进行热量传递。向水性环氧富锌涂料加入高导热填料后，一方面形成了以弹道-扩散的方式进行热量传递方式；另一方面添加的高导热物质在涂层中填充在孔隙和裂纹位置处，很大程度上提高了涂层的致密度，构建了变压器金属和外部环境的热量传递通道，因而使得涂料导热性能得到了显著提高。变压器温升模拟实验表明研制的新型高导热环保涂层可降低变压器油顶层温升1.67 K。

Research on improving thermal conductivity of transformer anti-corrosive coating

This study aims to develop a new type of environmentally friendly high thermal conductivity anti-corrosive coating for transformers. Graphene, carbon nanotube, carbon nano-horn and ultrafine graphite powder mixture are used to modify the thermal conductivity of the coating on the transformer surface. The thermal conductivity and microstructure of traditional solvent-based coatings, water-based epoxy zinc-rich coatings, and modified high thermal conductivity coatings are analyzed. Results show that the modified high thermal conductivity coating has the smallest thermal resistance (2.51℃/W) and the highest thermal conductivity (1.3460 W/(m·K)), indicating that its thermal conductivity is significantly better than those of the other two traditional coatings. This enhancement is mainly related to the optimization of the type of thermal conductivity and the improvement of coating density. After adding high thermal conductivity filler to the waterborne epoxy zinc-rich coating, a ballistic-diffusion scheme of heat transfer is formed. On the other hand, the added high thermal conductivity material fills the pores and cracks in the coating, which greatly improves the density of the coating and builds a heat transfer channel between transformer metal and external environment. The transformer temperature rise simulation experiment shows that the high thermal conductivity coating can reduce the top layer temperature rise of transformer oil by 1.67 K.