减免裸露电气接头热致故障的方法与材料研究

Research on methods and materials for reducing heat failure of exposed electric joints

理论分析发现，只要找到一种对太阳辐射的吸收率很小、而对长波红外辐射的发射率较大的光谱选择性辐射涂料，将它涂覆在裸露电气接头表面，就可有效地平抑其温度，进而降低其热致故障率。选择２０１ＢＴ材料作为光谱选择性辐射涂层，对其性能作了较为详细的研究。实验结果表明，涂有２０１ＢＴ材料的接头表面散热量增加，表面温度得到抑制，因而达到了降低热故障率的目的。实验还发现，２０１ＢＴ材料的红外发射率随温度的升高而减小，随涂层厚度变化不明显，经冷热循环老化后，发射率则有所提高。

Theoretical researches indicate that a spectral choice radiative coating material with small absorptivity for solar radition and great emissivity in the long wavelength regime can lower the exposed electric joints temperature efficiently. Therefore their heat-failure can be reduced. 2OIBT is selected in order to meet with the demand. Experiments show that emissivity of 2OIBT varies with different factors under fixed condition. It decreases while temperature rises, but has little variation while thickness varies. After cold and hot cycle, its emissivity increases.