核主泵用流体静压型机械密封性能的影响因素研究

Study on Factors Affecting Seal Performance of a Hydrostatic Mechanical Seal in Reactor Coolant Pumps

以核主泵(Reactor coolant pumps,RCP)用流体静压型机械密封(Hydrostatic mechanical seal,HS-MS)为研究对象,考虑辅助密封圈的影响,采用MSC Marc有限元软件建立完整的动环组件非线性二维轴对称有限元模型,给出合理的动环简化边界约束条件;在此基础上,考虑密封端面间流体薄膜中液体的黏温与黏压效应,建立核主泵用流体静压型机械密封的多场耦合数值模型,采用有限差分法对Reynolds方程、能量方程、热传导方程等控制方程进行耦合求解,利用有限元法计算密封环端面热力变形,综合分析螺钉预紧力和O形圈位置对密封性能的影响。结果表明:合理的密封环约束边界简化模型对分析和设计流体静压型机械密封至关重要;螺钉预紧力和O形圈位置对密封性能影响显著。预紧力增大使开启力增大,泄漏率也变大;O形圈位置靠近外径时密封稳定性下降。

A hydrostatic mechanical seal（HS-MS） for an nuclear reactor coolant pump（RCP） is studied.Marc finite element software developed by MSC Software Corporation is used to solve the whole non-linear two-dimensional axisymmetrical equations of the rotator by taking account of the influence of secondary seals on seal performance.The reasonable simplified boundary conditions for the rotator is presented.Based on this,a multiphysics coupled mathematic model for such a hydrostatic mechanical seal is established by considering the effect of temperature and pressure on viscosity of the sealed medium.Finite difference method is used to obtain the coupled solution of the Reynolds equation,energy equation,and thermal conduction equation,while finite element method is applied to compute the mechanical and thermal deformation of the end face.The effect of a bolt preload and the O-ring position on seal performance is comprehensively analyzed.The results show that a simplified model of seal ring with reasonable constrained boundary is vital for analyzing and designing a hydrostatic mechanical seal.Bolt preload of clamp and O-ring position have an apparent effect on seal performance.The bolt preload increases lead to an increased opening force and an increased leakage rate.When the position of O-ring is located on the outside of the rotator,the seal stability descend.