基于自由振荡理论的有压管道堵塞检测方法

Blockage detection in water-supply pipelines based on auto-oscillation theory

摘要:

为了解决有压管道的堵塞问题,根据自由振荡理论的基本原理,提出适于检测管道堵塞的数值模拟简化模型,得出了确定管道堵塞的定位与定量的方法．基于有压瞬变流理论,结合振动理论,引入迪拉克函数,建立包含堵塞的管道瞬变流控制方程;对方程进行无量纲化并线性化,使其得到简化．在固定边界条件下,求出相对压力的解析解,对其进行傅立叶级数分析,得到各谐波在各相对周期中的振幅,由此可计算出各谐波的衰减指数．求解结果表明:堵塞衰减与管道流量成正比,管道堵塞的相对位置与堵塞衰减参数呈余弦关系,只要已知两个谐波的堵塞衰减参数即可确定堵塞位置和堵塞量级．

Abstract:

Blockage in pressure pipelines has become a serious issue in the world. According to the basic principle of auto-oscillation theory, the simplified model is put forward for the numerical simulation of blockage detection. Based on the theory of transient flow, the governing equations of transients in a pipeline including blockage are established with the adoption of Dirac delta function. Non-dimensionalizing and linearizing the governing equation, the equations will be simplified. An analytical solution has been deduced under the fixed boundary conditions. By Fourier series analyzing, the amplitudes of each harmonic component in different periods are calculated, and the damping exponent of each harmonic component can be obtained. The results show that the blockage damping is direct ratio to the flow rate of pipe, and the location of damping has the cosine relation with damping parameters, so the location and magnitude of blockage can be fixed if two blockage damping parameters are known.