不同冲刷阀门对雨水管道沉积物清洁效率的数值模拟研究

Numerical study of different flushing gates on sediment cleaning efficiency in stormwater pipes

城市雨污混合制管道中的沉积物会导致管道腐蚀、排水效率降低,甚至管道堵塞,影响城市正常运转.在各种清洁方法中,使用产生冲刷波的冲刷装置已被广泛认为是一种有效和经济的解决方案.本文使用Flow-3D软件进行了一系列数值模拟计算,通过与文献中的实验进行水动力和泥沙冲刷对比,验证了该软件中泥沙冲淤模型的正确性,在此基础上利用该模型研究了3种简化的自动冲刷装置对管道沉积物的清淤效率.结果表明,半开口阀门高度对冲刷效率存在直接影响,阀门相对高度设置为0.2时冲刷效率最高.在3种阀门冲刷作用下,沉积层形态各异,冲刷效率也存在差异.开口阀门、倾倒式阀门、半开口阀门在冲刷下沉积床形态分别呈现直线形、V形和U形.半开口阀门条件下,清除全部沉积物所需的冲刷时间比开口阀门少30%.与开口阀门和倾倒式阀门相比,半开口阀门可分别节约75%和26%的水.

The sediment in urban rainwater and sewage pipes will lead to pipe erosion,reduce drainage efficiency and block the pipes,leading to the damage to the normal operation of the city.Among various cleaning methods,using self-cleaning devices that generate flushing waves to clean the sediment has been widely recognized as an effective and economical solution.In this paper,a series of numerical simulations were carried out using Flow-3D software.The model was verified by comparing the hydrodynamic and sediment erosion experiments in the literature.The flushing efficiency of three simplified automatic flushing devices for cleaning pipeline sediments was studied through simulation.The results showed that the height of half-open valve had direct influence on the scouring efficiency and the highest flushing efficiency was attained when relative height of the gate was 0.2.The sediment morphology and the scouring efficiency were different under the flush induced by three sluice types.The sediment bed morphology of open gate,tipping gate and half-open gate under scouring presented line shape,V shape and U shape,respectively.The flushed time of total sediment in half-open gate was 30%shorter than that in full-open gate.Compared with open gate and tipping gate,half-open gate can save 75%and 26%volume of water,respectively.