综合管廊排水系统潜水泵的临界淹没深度

Critical Submerged Depth of Sump Pump for Drainage System in Utility Tunnel

综合管廊设有雨水渗透、外部通风口、人员进出口、投料口等外部开口,一旦发生紧急进水,排水系统是保障管廊安全运行的重要附属设施。通过对北京、上海及海口等管廊考察,确立了典型管廊排水系统示意简图,建立了集水坑排水模型,使用计算流体动力学软件对排水过程进行模拟,探究了潜水泵的临界相对淹没深度,提出了一个新的廊内集水坑理想条件、入口速度恒定和入口速度连续变化三种工况下的经验公式,并将该经验公式与常用的三种经验公式(Knuass公式、Hecker公式和何耘公式)进行详细对比讨论,可为管廊排水系统集水坑的设计、潜水泵的布置与安全评价的决策提供指导性建议。

There are some external openings such as rainwater infiltration,external vents,personnel entrances and feed openings in the utility tunnel.The drainage system is an important auxiliary facility for the emergency entry of pipe tunnel.Through in-site investigation of utility tunnels in Beijing,Shanghai and Haikou,a schematic diagram of the typical water drainage system of utility tunnels was established,and a sump drainage model by computational fluid dynamics software was built then.Hence the drainage process was simulated,and the critical submerged depth of the sump pump was explored.A new empirical formulas of the ideal conditions,the fixed inlet velocity and the continuous change of the water inlet velocity in the pipe tunnel were proposed,furthermore,it was compared and analyzed with the common three empirical formulas as Knuass formula,Hecker formula and Heyun formula in detail.The results can provide guidance for the design of the sump of the drainage system,the layout of the sump pump and the decision of safety evaluation.