[关键词]
[摘要]
为研究闸站并列布置工程泵站运行时清污机桥位置对前池内水流流态的改善效果,以南水北调东线刘山泵 站工程为例,基于 Navier-Stokes 方程和 Standard?k-ε 湍流模型对前池原设计方案和改进设计方案的进水流场进行 了定常数值模拟,分析比较不同开机组合时前池流场分布和流道进口后断面的流速分布均匀度及速度加权平均 角度,并进行水工模型试验验证。结果表明:原设计方案前池在 4 号和 5 号机组进水流道进口前存在回旋区,4 号 机组流道进口前产生有害吸气旋涡;改进设计方案前池将清污机桥整体向泵房方向移动 25?m,并将节制闸与泵站 间导流墙长度减短使其头部与清污机桥墩齐平,不仅消除了 4 号机组流道进口处有害吸气涡,还将 4 号机组进水 流道进口流速分布均匀度平均提高 2.5%,泵站进水流态改善显著。通过调整泵站进口清污机桥桥墩位置解决了 前池流态存在的问题,不需再另增底坎、立柱和导流墩等措施,研究成果可为同类型工程研究提供参考。
[Key word]
[Abstract]
The?project?of?pumping?station?with?parallel?sluice?has?the?advantages?of?compact?layout?and?small?land occupation,?and?it?is?widely?used?in?water?conservancy?projects.?For?the?project?of?pumping?station?with?parallel sluice,?the?flow?direction?of?the?water?flows?into?the?forebay?has?a?certain?angle?with?the?longitudinal?center?line?of the?forebay?when?the?pumping?station?is?working,?so?that?deviation?and?backflow?is?prone?to?appear?in?the?forebay?of pumping?station,?the?flow?pattern?at?the?inlet?of?the?inlet?conduit?will?be?deteriorated,?and?a?suction?vortex?belt?will be?generated?in?severe?cases.?The?safe?and?stable?operation?of?the?pump?unit?will?be?affected?when?the?suction?vortex belt?enters?the?pump.?In?order?to?study?on?the?improvement?of?flow?pattern?in?the?forebay?when?the?pumping?station?of?the?project?is arranged?in?parallel?with?the?sluice?station,?taking?the?Liushan?Pumping?Station?in?the?Eastern?Route?of?the?South-to-North?Water?Transfers?Project?as?an?example,?the?numerical?simulation?study?on?the?flow?pattern?in?forebay?of?the project?of?pumping?station?with?parallel?sluice?was?carried?out?based?on?the?Navier-Stokes?equations?and?the?RNG ?turbulence?model.?Aiming?at?the?flow?field?problems?in?the?forebay,?the?improvement?measures?of?moving?the cleaning?machine?bridge?to?the?pump?house?and?shortening?the?length?of?the?diversion?wall?between?the?sluice?and the?pumping?station?were?proposed,?and?the?flow?pattern?in?the?forebay?under?different?schemes?was?analyzed?based on ?the ?numerical ?calculation ?results, ?the ?uniformity ?and ?average ?angle ?of ?the ?cross-sectional ?flow ?velocity distribution ?after ?the ?inlet ?of ?the ?inlet ?conduit ?of ?each ?pump ?unit ?were ?compared, ?and ?finally ?the ?numerical calculation?results?were?verified?by?the?method?of?hydraulic?overall?model?test. ??????The?research?results?show?that?there?was?a?reflux?vortex?area?in?the?original?forebay?before?the?inlets?of?inlet conduits?of?No.?4?and?No.?5?pump?units?of?the?Liushan?Pumping?Station?in?the?Eastern?Route?of?the?South-to-North Water?Transfers?Project,?and?a?harmful?suction?vortex?was?generated?before?the?inlet?of?inlet?conduit?of?No.?4?pump unit.?In?the?improvement?scheme?of?forebay,?the?cleaning?machine?bridge?was?moved?by?25?m?to?the?pump?house?as a?whole,?and?the?length?of?the?diversion?wall?between?the?sluice?and?the?pumping?station?was?shortened?so?that?its head?was?level?with?the?pier?of?cleaning?machine?bridge.?The?range?of?the?swirl?flow?in?the?forebay?was?effectively compressed?and?the?intensity?of?the?swirl?flow?was?weakened.?Not?only?the?harmful?suction?vortex?at?the?inlet?of?the inlet?conduit?of?No.?4?pump?unit?was?eliminated,?but?also?the?uniformity?of?the?flow?velocity?distribution?at?the?inlet of?the?inlet?conduit?of?No.?4?pump?unit?was?increased?by?2.5%?on?average,?and?the?inlet?flow?pattern?of?the?pump station?was?significantly?improved.?The?on-site?operation?of?the?Liushan?Pumping?Station?over?the?years?shows?that there?is?no?bad?flow?pattern?in?the?forebay?under?the?conditions?of?different?start-up?combinations,?and?the?pumps operates?steadily. ??????The?position?of?the?suction?vortex?before?the?inlet?of?the?inlet?conduit?is?accurately?predicted?by?the?method?of numerical?simulation?of?the?forebay?flow?field?in?project?of?pumping?station?with?parallel?sluice,?and?the?numerical calculation?results?are?basically?consistent?with?the?model?test?results?and?field?observation?results.?The?problem?of the?flow?pattern?in?the?forebay?is?solved?by?adjusting?the?position?of?the?pier?of?the?cleaning?machine?bridge?of?the pumping?station?without?adding?measures?such?as?bottom?sill,?column?and?diversion?pier.?The?research?results?can provide?reference?for?the?same?type?of?engineering?research.
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[基金项目]