长距离高落差重力流输水管道水锤特性分析

摘要

In the high fall gravitational water-supply projects, to avoid the high static pressure happening in the downstream pipeline during operation dispatching, methods commonly used are setting multistage energy-dissipating measures along the pipeline, and calculation and analysis of water hammer must be done when the valve of gravity flow pipeline opening or closing. Based on the simplified energy dissipation box physical model and the characteristic method, the mathematical model of the energy dissipation box and the characteristic line equation for calculation and analysis of water hammer were put forward in this paper. Combined with practical work, the paper analyzed the hammer characteristics of the high fall gravitational water-supply project in the process of valve opening and closure. The calculation results show that the valve opening process in high fall gravitational system is relatively safe and the minimum pressure along the pipeline is mainly determined by the initial internal water pressure, which is little related to valve open velocity, so the minimum pressure along the pipeline can be effectively controlled by increasing the initial internal water pressure. The valve closure process is more dangerous than that in the normal gravitational water-supply protects and the first-phase water hammer happens easily, so the valve closure velocity must be strictly controlled.%高落差重力流有压输水工程中，为避免在运行调度中下游管道静水压力较高，常在管路沿线设置多级消能措施，重力流管道阀门启闭会引起水锤现象，须进行水锤计算分析。通过简化消能箱物理模型，结合水锤计算分析特征线法提出了消能箱的数学模型以及用于水锤计算分析的消能箱两侧特征线方程。结合工程实例分析了高落差重力流输水工程在开阀及关阀过程中的水锤特性。结果表明：高落差重力流的开阀过程较为安全，其沿线最小压力由初始内水压力决定，受开阀速度的影响较小，提高管道初始压力可有效控制沿线最小压力；其关阀过程较普通重力流更危险，容易发生首相水锤，必须严格控制关阀速度。