低压输水单元水力振荡的数值研究

在长距离分段低压输水系统中,为防止过大的流量波动,系统中不能产生过大的水力振荡,尤其不能发生水力共振,因此必须对其振荡特性进行分析,以保证系统的正常稳定运行。本文采用基于压力管道内水体水力振荡的线弹性模型描述输水管道中水流的控制方程,利用状态方程来描述输水单元。基于系统控制理论,分析了采用不同阶数的线弹性模型时输水单元的频率特性。同时,分析了三阶线弹性模型的特征值与输水单元参数的相关性,以及各特征频率对输水单元的影响。其结论可为输水系统的设计和优化提供依据。

Study on hydraulic oscillations in low-pressure water-supply unit

To avoid excessive discharge variation in stepped low-pressure water-supply systems,severe hydraulic oscillations,especially hydraulic resonances are not allowed in these systems,and design and operation of such systems need analysis of the oscillations to ensure operation stability.This paper uses a linear elastic model to describe the basic equations of the flow in a pressurized pipeline and compares its versions of different orders on the basis of modern control theory.The results indicate that the third-order model is more effective and a correlation analysis of the model’s eigenvalues with the system parameters shows the importance of fundamental frequencies to a water-supply system.These results provide useful suggestions for the design.