水在高温硫化硅橡胶中的扩散特性研究  

Investigation on Water Diffusion Property Into HTV Silicone Rubber

作　　者：高岩峰[1] 王家福[1] 阎志鹏[1] 梁曦东[1] 刘瑛岩[1] 

机构地区：[1]电力系统及发电设备控制和仿真国家重点实验室(清华大学电机工程与应用电子技术系),北京市海淀区100084

出　　处：《中国电机工程学报》2015年第1期231-239,共9页Proceedings of the CSEE

基　　金：国家重点基础研究发展计划项目(973项目)(2011CB209406)~~

摘　　要：水分侵入是造成复合绝缘子高温硫化硅橡胶伞裙、护套材料老化的主要因素之一。为了获得能够准确描述水分子在硅橡胶中扩散的扩散模型和扩散特性,使用固体核磁共振(nuclear magnetic resonance,NMR)技术,分析了水分子在硅橡胶中的存在状态;并通过称重法试验,获得了水分子在硅橡胶中扩散时硅橡胶的增重曲线。研究表明,水分子在硅橡胶中存在"自由态"和"结合态"两种不同的状态。固体核磁共振和称重法的试验结果都表明,水分子在硅橡胶中的扩散过程符合Langmuir扩散模型,而不符合经典的Fick扩散模型。同时研究了水分子扩散过程的影响因素,结果发现:自由态水分子的含量随温度的升高而增加,结合态水分子的含量随温度的升高而降低,且温度对扩散系数的影响符合经典的Arrhenius方程;硅橡胶中的氢氧化铝(ATH)填料含量的增加会导致结合态水分子含量的增加,但ATH含量对自由态水分子含量的影响不显著。Moisture plays a major role in the aging phenomena of high temperature vulcanizing silicone rubber material, which is always used as composite insulator sheds and sheath. In order to obtain an appropriate model to describe the water molecule diffusion process into silicone rubber, as well as the diffusion characteristics of this process, the solid state nuclear magnetic resonance （NMR） was conducted to investigate the existence state of water molecule in silicone rubber. The gravimetric method was also employed to obtain the weight gain curves caused by the water molecule diffusion. The study shows that water molecules had two different states in silicone rubber, one is “free” state and the other one is “bound” state. By combining the results of NMR analysis and gravimetric method analysis, the model of water diffusion into silicone rubber was suggested, i.e., this diffusion process could be explained quantitatively by a Non-Fick diffusion model, Langmuir diffusion model, instead of the classical Fick diffusion model. In addition, the paper studied the influence factors of the diffusion process of water molecules into silicone rubber; the study indicated that the amount of free state water increased with temperature increasing and the amount of bound state water decreased with temperature increasing. The effect of temperature on the diffusion coefficient is in accordance with the classical Arrhenius equation. The increasing the amount of the Alumina Tri-hydrate（ATH） content in silicone rubber had the effect of increasing the amount of bound state water, however, the amount of free state water is relative insensitive to the ATH content.

关 键 词：高温硫化硅橡胶 水分子 扩散过程 固体核磁共振 Arrhenius方程 

分 类 号：TM855[电气工程—高电压与绝缘技术]