基于COMSOL热流固耦合的金属氧化物避雷器密封结构优化

Optimization of Sealing Structure of Metal Oxide Arrester Based on COMSOL Thermal-fluid-solid Coupling

金属氧化物避雷器在电力系统中应用广泛,但是在其运行过程中,由于环境因素影响,盖板与瓷套间的O形橡胶密封圈可能出现密封失效问题。为提高金属氧化物避雷器密封结构的可靠性,提出了1种具有气压缓冲功能的由2道O形橡胶圈组成的密封结构,在COMSOL有限元分析软件中建立了MOA三维模型以及密封结构简化等效模型,并对典型密封结构以及多级密封结构进行了热–流–固耦合仿真,分析了2种结构的接触应力以及von Mises等效应力。实验结果表明:多级密封结构与典型密封结构的接触应力均大于MOA内部气压,能够实现有效密封;在相同环境条件下,多级密封结构具有气压缓冲功能,von Mises应力比典型密封结构小,且能缓冲因温度变化导致的密封圈应力变化。考虑密封可靠性与结构尺寸等因素;2级密封结构具有结构紧凑、防潮性能好以及冗余度适当等综合优势。

Metal oxide arrester is widely used in power system, but in its operation process, failure in O-shaped rubber sealing ring between cover plate and porcelain bushing may appear due to environmental factors. In order to improve the reliability of sealing structure of metal oxide arrester, a sealing structure consisting of two O-rings with air pressure cushioning function is proposed in this paper. A three-dimensional MOA model and a simplified equivalent model of sealing structure are established by the COMSOL finite element analysis software. Thermal-fluid-solid coupling simulation of typical sealing structure and multi-stage sealing structure is carried out, and the contact stress and von Mises equivalent stress of the two structures are analyzed. The experimental results show that the contact pressure of the multi-stage sealing structure and the typical sealing structure is greater than the internal pressure of MOA, so the effective seal can be achieved. Under the same environmental conditions, the multi-stage sealing structure has the function of air pressure buffer, the von Mises stress is smaller than the typical sealing structure, and it can buffer the seal ring stress change caused by the temperature change after the factors of sealing reliability and structure size are taken into consideration, meanwhile, the two-stage sealing structure has the comprehensive advantages of compact structure, good moisture-proof performance, and appropriate redundancy.