长距离重力流树状输水管网水锤模拟分析

Water hammer simulation analysis of long distance gravity flow tree water transmission pipe network

结合某安全饮用水工程实际,采用水锤计算的特征线法建立了长距离重力流树状管网输水系统水锤计算的数学模型,应用MATLAB编程计算了不同关阀(开阀)程序对输水干管水力过渡过程的影响。研究项目干管1#阀门选择蝶阀,2#和3#阀门选择两阶段关闭液控蝶阀,支管选择水力遥控浮球阀(4#~12#)。水力遥控浮球阀均30 s线性关闭;1#蝶阀10 s线性关闭;2#蝶阀和3#蝶阀两阶段关闭,快关角度为70°,快关/慢关时间分别为15 s和400 s、15 s和350 s。结果认为最优开阀程序为:1#、2#和3#蝶阀匀速开启,开启时间分别为10 s、80 s以及230 s;4#~12#水力遥控浮球阀均30 s线性开启。当阀门关闭(开启)时间不小于上述时间,就能保证工程安全运行。

Combined with the actual conditions of a safe drinking water project,a mathematical model was estab⁃lished by characteristic line method for the water hammer calculation of long distance gravity flow tree water trans⁃mission pipe network.The impact of different valve closing(opening)procedures on the hydraulic transition process of main pipe was calculated by MATLAB programming.Butterfly valve is selected as No.1 valve on main pipe.No.2 valve and No.3 valve on main pipe are both two-stage closing hydraulic butterfly valves.No.4~No.12 valves on the branch pipes are hydraulic remote control float ball valves.The calculated closing time include 30s linear closing for hydraulic remote control float ball valve,10s linear closing for No.1 butterfly valve,two-stage closing for No.3 and No.4 butterfly valves both with a quick closing angle of 70°and with the quick/slow closing time of 15s/400s and 15s/350s respectively.The calculated optimum valve opening procedures are 10s/80s/230s uniform speed open⁃ing for No.1/No.2/No.3 butterfly valves,30s linear opening for No.4~No.12 hydraulic remote control float ball valves.When the valve closing(opening)time is not shorter than the above mentioned time,operation safety of the project is ensured.