不对称引水系统双调压井涌波研究

在无阻尼的假定下,建立并求解了不对称引水系统双调压井涌波的二元二阶微分方程组.研究表明:双调压井涌波存在两个波动频率,任意一个调压井涌波波动为两个波函数之和,而涌波波幅与引水系统水力参数、涌波方程的初始条件有关.以某电站为例,采用两机组导叶瞬间关闭的假定处理初始条件,研究调压井涌波波幅与引水系统水力参数的关系,揭示了不对称双调压井引水系统控制工况下,小机组对应的小调压井涌波波幅在一定范围内并不随着调压井面积的增加而减少的特殊现象.提出不对称引水系统双调压井的面积设计还应根据涌波波幅与调压井面积的变化曲线、避开使得调压井涌波波幅较大的区域的观点.

Study of water level fluctuation of double surge tanks of asymmetric water diversion system

Without consideration of damping,this paper establishes and solves the binary second order differential surge wave fluctuation equations for the asymmetric water diversion system with double surge tanks,which turns out that two wave frequencies exists in the water diversion system,wave fluctuation in either surge tank is the sum of two wave function;and the wave amplitude is associated with water diversion system’s hydraulic parameters as well as initial conditions of the equations.Taking a certain hydropower station for example,on the assumption of instant guide vane closure,this paper studies the relationship between wave amplitude and water diversion system’s hydraulic parameters,and reveals the special phenomenon that surge wave amplitude of small surge tank for the small unit doesn’t always decrease when area of either surge tank increases.Therefore,the area of double surge tanks should be determined according to the changing curve between wave amplitude and area of either tanks.