汽轮机高压主汽门关闭过程的动力学模型

汽轮机高压主汽门传动机构主要由1个阀杆、3个连杆和1个活塞杆组成。分析得出系统完整约束方程组,用凯恩方法导出传动机构动力学方程,并求出代数-微分方程组的数值解。当连杆转动角均为微量时采用拉格朗日方程得到传动机构近似模型。近似模型是一个单自由度系统,其运动学方程可以解耦,动力学方程可用龙格-库塔法求解。结果表明:近似模型能比较准确地描述阀杆和活塞杆的平动和1个连杆的转动,但不能反映另外2个连杆的摆动。尽管如此,近似模型仍可用来计算关阀时间和阀杆速度。图5参2

Dynamic Model of the Closing Process of a High Pressure Turbine''''s Throttle Valve

The transmission mechanism of a high pressure turbine's throttle valve mainly consists of a valve stem,three linking bars and a piston rod.Analysis of the system provides a set of equations;with the help of Kane's method the dynamic equation of transmission is deduced and the numerical solution of the set of algebraic-differential equations found.An approximate model of transmission for small angular displacement of the links is obtained by making use of Lagrange's equation.This model has only one degree of freedom;its kinematic equation can be decoupled and the dynamic equation solved by the Runge-Kutta method.Results that this model can express with relative accuracy the translation of both the valve stem and the piston rod,as well as the rotary movement of one link,but not the swinging motion of the other two links.Nevertheless,it may be used to calculate the closing time and the velocity of the valve stem.Figs5 and refs2.