泵站直边正向前池流态模拟与泥沙淤积预防措施

Flow simulation of front inflows in the straight-edge forebay of pumping station and preventive measures of sediment deposition

针对从高含沙河道取水的大型泵站直边正向前池泥沙淤积导致前池调节能力下降、泵站运行效率低下等问题,利用ICEM-CFD软件构建原型前池结构三维模型,采用FLUENT软件基于Standard k-ε湍流模型对前池流态进行模拟分析,并针对不良水流流态提出增设导流墩与压水板2种优化措施。结果表明,数值模拟结果与实际调查情况相一致,前池水流流态紊乱,泥沙淤积较严重,八字形导流墩可在一定程度上削减主回流区范围,但对前池水流仅起到分配作用,流场分布无明显改善;45°压水板能有效改善前池主流效应,两侧回流区明显减弱,在改善前池泥沙淤积问题的同时保证了水泵有利的进水条件。

Due to the sediment deposition occurring in front inflows of the straight-edge forebay of large pumping station, where its water is taken from the river with high content of sand, the adjustment ability of the forebay is usually reduced and the operation efficiency of the pumping station becomes low. To solve this problem, a prototype 3D model of the forebay structure is established using the ICEM CFD software, with its flow regime being modelled and analyzed by using Standard k-e turbulence model in the FLUENT software. Moreover, two optimization measures are proposed for the bad flow regime by incorporating diversion pier or water pressure plate. The findings show that the computed results are consistent with those from site survey, the flow regime in the forebay is in disorder and the sand sedimentation is quite serious. The eight-shaped diversion pier can reduce to some extent the scope of the main re-circulation region, but only serves as allocating of the forebay flow without obvious improvement in its flow filed distribution. On the contrast, the 45 ° water pressure plate can effectively improve the mainstream effect in the forebay, and the back-flow region on both sides is obviously reduced. The sand sedimentation problem in the forbay is thus solved with the favorable inflow conditions being ensured for the water pump.