侧边机组故障对泵站前池流态的影响

Influence of Side Units Failure on the Flow Pattern of Pump Station Fore-bay

为研究侧边机组故障对泵站前池流态的影响,本文建立了某泵站引渠、前池、进水池与吸入管三维数值模型,并基于VOF模型开展了数值计算。然后,根据计算结果分析了不同侧边机组故障情况对前池和引渠内流态的影响。最后,引入了流速分布均匀度作为量化指标,阐述了不同侧边机组故障情况对中间机组的吸入管进口流速分布的影响规律。结果表明:侧边单台机组故障时,前池内部流速分布相对无故障变化较小,但故障机组吸水池内产生大尺度漩涡,进而导致前池出口断面流速畸变,发生流速掺混现象;侧边机组全部故障时,前池内部产生大尺度涡系,造成前池出口断面流速严重掺混现象,且范围更大,并显著影响中间机组吸入管进口流态,造成进口流速不均匀分布,进而对中间机组运行产生不利影响。

In order to study the effect of side pump units failure on the flow pattern in the fore-bay of a pumping station,a three-dimensional numerical model which includes approach channel,fore-bay,intake basin and suction pipe of a pumping station was established.And numerical calculations were carried out based on the VOF model.Then,the effects of different side pump units failures on the flow patterns in the fore-bay and approach channel were analyzed based on the calculation results.Finally,the uniformity of flow velocity distribution was introduced as a quantitative index,and the influence law of different side unit failure conditions on the inlet flow velocity distribution of the inlet pipe of the intermediate unit was described.The results show that when the single side unit fails,the velocity distribution in the fore-bay changes slightly compared with the no fault condition.But the large scale vortex is generated in the intake basin of the failed pump unit,which leads to the blending and distortion of the flow velocity in the outlet section of the fore-bay.When all the side pump units fail,the large scale vortex system is generated in the fore-bay,which results in the serious blending of the flow velocity in the outlet section of the fore-bay and significantly affects the inlet flow pattern of the middle pump units.All the side pump units fail also result in the uneven distribution of the inlet velocity and thus detrimental to the stability of the middle pump units.