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为建立反击式水轮机动态模型,本文考虑了如下因素:1)根据水锤机制和水锤波是流体弹性纵波的性质,导叶稠密度l/t>1,水锤波的波长小于导叶表面曲率半径,压力行波不能穿透在圆周上均匀布置的多导叶组成的叶栅。因而导水机构作为水锤界面来划分水轮机水锤的上游系统和下游系统;2)采用水力机械广义基本方程式,动态力矩以相对值表示时,可写成:m_d=m_—T_(at)(dx)/(dt)+T_(wt)(dq)/(dt)。式中m_d为动态力矩的相对值;m_t为以动态参数表示的基本力矩相对值;T_(wt)和T_(at)分别表示转轮区流动液体的暂态惯性时间常数,表征二项附加力矩;3)由于导叶动作引起水流变化到转轮叶片反应出这种变化存在一定的流程滞后(作为滞后环节考虑)。由动态模型框图说明这些因素之间动态关系。
In order to establish the dynamic model of the impact turbine, the following factors are considered in this paper: 1) According to the water hammer mechanism and water hammer wave, the vane density is l / t> 1 and the wavelength of the water hammer wave is smaller than the surface of the vane Radius of curvature, pressure traveling wave can not penetrate the cascade of multi-guide vanes evenly arranged on the circumference. Therefore, the water guide mechanism is used as a water hammer interface to divide the upstream system and the downstream system of the hydraulic hammer of the hydraulic turbine. 2) When the dynamic torque is represented by relative values using the generalized basic equations of a hydraulic machine, it can be written as: m_d = m_T_ (at) ) / (dt) + T_ (wt) (dq) / (dt). Where m_d is the relative value of the dynamic torque; m_t is the relative value of the basic torque represented by the dynamic parameters; T_ (wt) and T_ (at) respectively represent the transient inertia time constant of the fluid in the rotor zone, ; 3) due to the guide vane movements caused by changes in water flow to runner blades reflect this change there is a certain process lag (as a hysteretic link considerations). A dynamic model diagram illustrates the dynamic relationship between these factors.