核级氦气隔离球阀泄漏模式分析及结构优化

Leakage Mode Analysis and Structure Optimization of Nuclear Helium Isolation Ball Valve

核级氦气隔离球阀是高温气冷堆燃料装卸系统的重要承压设备,需要满足高温、高压和高辐照工况下的高渗透性氦气介质的密封性能,同时需要具备通过球形燃料元件的功能。传统的球阀结构存在氦气工况下的泄漏风险,并且无法满足过球的功能。本文通过特殊结构设计,采用磁力传动器的方案以及阀体与阀盖之间的密封结构设计,将动密封转化为静密封,解决了阀杆处的外泄漏。通过阀座与阀体之间的波纹管焊接密封结构设计,将球阀启闭过程中的阀座处的动密封转化为静密封,解决了阀门的内泄漏。从而使得研制的核级氦气隔离阀能够满足整机泄漏率的要求。

Nuclear grade helium isolation ball valve is an important pressure bearing equipment in the fuel handling system of high temperature gas cooled reactor,which needs to meet the sealing performance of high permeability helium medium under high temperature,high pressure and high irradiation conditions,and also needs to have the function of passing through spherical fuel elements.The traditional ball valve structure has the risk of leakage under helium working condition,and cannot meet the function of passing the ball.In this paper,through the special structure design,the magnetic driver scheme and the sealing structure design between the valve body and the bonnet are adopted to convert the dynamic seal into a static seal to solve the leakage at the valve stem.Through the design of the welded seal structure of the bellows between the valve seat and the valve body,the dynamic seal at the valve seat during the opening and closing process of the ball valve is transformed into a static seal,which solves the internal leakage of the valve.Therefore,the developed nuclear helium isolation valve can meet the requirements of the leakage rate of the whole machine.