“V”形输水管道爆管过渡过程分析与事故控制策略优化

Pipe bursting transients analysis and accident control strategy optimization for a water delivery pipeline with V-shaped longitudinal profile

爆管事故是"V"形输水管道运行中可能发生的极端工况,控制外泄流量、防止隔断阀关闭产生2次爆管是爆管事故处理应关注的2个方面.结合工程实例,研究了爆管位置、爆管面积、爆管历时等不确定因素对爆管水力过渡过程的影响,建立了隔断阀关闭规律的优化模型并采用免疫粒子群算法求解,研究了关闭滞后时间对爆管控制效果的影响.结果表明:1)爆管点越低,爆管面积越大,外泄流量越大,爆管点上游正向过阀流速和爆管点下游反向过阀流速越大.2)爆管点既是水锤发生的根源,又具有压力释放作用,最大水锤压力随爆管面积的增大呈现"先增大、后减小"趋势.3)以管线水锤压力和过阀流速最小为目标函数,以上下游隔断阀的关阀序律参数为决策变量建立优化模型,采用免疫粒子群算法(IAPSO)进行求解,可以在保证安全的前提下,尽快关闭阀门,减小爆管损失.

For a water delivery pipe line with V-shaped longitudinal profile, pipe-bursting is a possible extreme accident. Controlling the escaping flow and preventing the secondary water hammer during the closure of isolating valves are the two aspects which should be considered for the pipe-bursting accident treatment. In this paper, combining with an engineering example, the effects of three uncertain factors, including pipe-bursting location, pipe-bursting area and the total time of pipe-bursting process, on the pipe-bursting transients are analyzed. Moreover, an optimization model for the closure rules of isolating valves is established;and then the immunity with algorithm particle swerm optimization(IAPSO) method is used to solve the model. Also, the influence of the lag time of isolating valves closure on pipe-bursting controlling is studied. The study results show that: 1. The lower the pipe-bursting location and the larger the pipe-bursting area, the lager the escaping flow, the larger the positive flow velocity across the upstream valves and negative flow velocity across the downstream valves. 2. The pipe-bursting point is a water hammer source, as well as a pressure releaser. So with the increase of the pipe-bursting area, the maximum water hammer pressure first increases and then decreases. 3. Taking the minimum values of water hammer pressure and flow velocity across valves as objective function, the closing scheme parameters of isolating valves as decision variables, an optimization model is established and solved by using immune particle swarm optimization(PSO) method. The optimization results can shortent the valve closing time and reduce the pipe-bursting damage under the premise of pipe safety.