一种汽轮机再热主汽阀门机构的动力学建模与虚拟样机仿真

Dynamic Modeling and Virtual Prototyping of a Steam Turbine Reheat-Stop-Valve Mechanism

针对汽轮机再热主汽阀门机构运行卡涩的典型问题,为描述阀轴与衬套的实际运动接触状态,考虑阀轴与衬套的装配同轴度误差,建立了径向轴承铰和阀门机构的动力学模型,并在不考虑阀轴与衬套的装配同轴度误差情况下,利用COSMOS动力学分析软件建立了阀门机构的功能化虚拟样机.通过理论分析和虚拟样机仿真,研究了装配同轴度误差对阀门机构动力学特性的影响.研究结果表明:装配同轴度误差是影响汽轮机再热主汽阀门机构动态行为的重要因素,不同的误差值对约束反力和摩擦阻力矩的变化影响显著.

Aiming at the practical motion-blocked problem of a steam turbine reheat-stop-valve mechanism, for interpreting the practical interactive behavior between valve shaft and bush, a new journal-bearing dynamic model including the assembly coaxial error was proposed. And the dynamic model of overall valve mechanism was implemented by modeling the revolute joint with clearance consequently. A functional virtual prototype excluding the assembly coaxial error with simulation analysis was also completed by COSMOS. The dynamic characteristics of valve mechanism were investigated by contrastively analyzing in theorizationand simulation process. Asaresult, the concentricity of two pair elements is derived as one of the critical factors for dynamical characteristics of the valve mechanism. The different values of assembly coaxial error will change the reaction force and friction moment of revolute joint remarkably.