长链硅氧烷修复液抑制电缆铝芯腐蚀的机理及修复效果研究

Mechanism of Long-chain Siloxane Rejuvenation Fluid in Preventing Cable Aluminum Core from Corroding and Its Rejuvenating Effect

为研究长链硅氧烷在抑制修复液腐蚀电缆铝芯方面的效果及其对水树老化交联聚乙烯(XLPE)电缆绝缘性能的提升效果,采用两种不同配方的修复液对铝芯进行腐蚀,观察铝芯的质量变化和表面微观结构变化;同时采用两种修复液对水树老化电缆进行修复,分析电缆的电气性能和XLPE绝缘的微观结构变化。结果表明:添加了长链硅氧烷的修复液造成的铝芯质量损失小于未添加长链硅氧烷的修复液;采用两组修复液修复后,电缆的电导率和非线性系数明显下降,0.1 Hz下的介质损耗因数也下降,并且添加了长链硅氧烷修复液的一组电导率和低频介质损耗因数均小于未添加长链硅氧烷修复液的一组。分析认为,修复液反应生成的甲醇是导致铝芯腐蚀的原因,长链硅氧烷可以抑制修复液的水解,降低单位时间内生成的甲醇含量,从而抑制修复液对铝芯的腐蚀危害。基于以上发现,证明了添加长链硅氧烷的修复液对铝芯的腐蚀作用降低,同时修复绝缘老化的效果更佳。

In order to investigate the effect of long-chain siloxane in preventing rejuvenation fluid from corroding the cable aluminum core and the promoting effect on properties of water tree aged XLPE cable insulation,we used two rejuvenation fluids to corrode the aluminum cores,and then studied the mass changes of aluminum cores and their surface micro-structures.Meanwhile,the water tree aged cables were repaired by the two rejuvenation fluids,and the electrical properties variation of cables and the micro-structure variation of XLPE insulation were analyzed.The results show that the mass loss of aluminum core caused by the rejuvenation fluid with long-chain siloxane was less than that without long-chain siloxane.After rejuvenation,both the conductivity of cables and its nonlinear coefficient decrease obviously,the dielectric loss factor at 0.1 Hz also decreases,and both the conductivity and dielectric loss factor at low frequency of the group with long-chain siloxane rejuvenation fluid are less than that without long-chain siloxane rejuvenation fluid.It is considered that methanol,generated by the reaction of rejuvenation,is the reason of aluminum corrosion.The long-chain siloxane can inhibit the hydrolysis of rejuvenation fluid and reduce the content of methanol produced per unit time,which inhibits the corrosion of aluminum core by rejuvenation fluid.Based on above findings,it is proved that the rejuvenation fluid with long-chain siloxane has little effect on the corrosion of aluminum core and has better repairing effect.