| Comprehensive water conservancy projects often need to undertake flood control,drainage,diversion and other functions.As a comprehensive water conservancy project,sluice-station combined water conservancy project has the advantages of less land requisition,saving immigration investment and facilitating integrated control.It is more and more applied to practical projects,but the inflow field of sluice-station combined water conservancy project is complex.In order to ensure the safe and stable operation of the project,it is often necessary to take some measures for rectification to ensure the smooth flow of the project.Xihe Fenghuangjing Gate Station Project is an asymmetric water conservancy hub.The hub has the functions of pumping and drainage,self-drainage and self-traction.A long pier cleaning machine bridge is set up in the upstream.Due to the different elevations between the sluice and the bottom plate of the pumping station,the diversion wall is set up between the sluice and the pumping station,and between the outlet of the pumping station and the stilling basin from the bridge of the cleaner.In the design scheme,the water outlet is set on the diversion wall.Based on the project of Fenghuang Neck Gate Station in Xihe River,this paper proposes rectification measures for the bad flow pattern in the forebay of pumping station by means of physical model test,and studies the arrangement of openings on diversion walls of forebay and outlet by means of numerical simulation test.The main research results are as follows:(1)During the pumping and drainage operation of the pumping station,a large range of low-speed gyration areas appear in the forebay under the design conditions,and serious suction vortices appear in front of each inlet.The physical model test proposed multiple rectification measures to optimize the flow pattern of the inlet forebay.By optimizing the connection mode between diversion wall and pier head,reducing the slope of the forebay,shortening the length of the interval pier of the pump station channel and closing the water passage hole on the diversion wall,the suction vortex in the inlet channel can be eliminated,the low-speed gyration area of the forebay can be reduced and the sedimentation in the forebay can be reduced.(2)In order to explore the optimal opening scheme on the diversion wall of the forebay,CFX numerical simulation software was used to analyze the layout of the water holes on the diversion wall under design conditions.The analysis results show that:(a)when the diversion wall is set with water outlets,the equal distance arrangement of water outlets on the diversion wall of the forebay is better than that of the first-end arrangement;small area opening is better than large area opening;when the ratio of opening height to depth is 1/4,the flow pattern is the best.(b)When the diversion wall does not set the water hole:because the transverse velocity generated by the water hole disappears,the large-scale gyration area of the front pool shrinks,and the flow pattern of the front pool of the pumping station is better than that of all the opening schemes.After the physical model test,in other conditions,the diversion wall does not open holes can ensure that the pump station pool has a good inflow state.(3)In the process of self-induction operation of the sluice,due to the asymmetric layout of the sluice and station,a large deviation angle is generated in the mainstream,and a vortex area is generated near the diversion wall of the pumping station outlet pool.The vortex area forms the inflow deviation,resulting in the deterioration of the inlet flow state of the sluice.Under the condition that the length of the diversion wall is not adjusted,the inlet water of the sluice is optimized by using the opening on the diversion wall.The study shows that when the diversion wall is equal to three holes,the vortex area has the smallest influence on the inflow of the sluice.When the opening depth ratio is 5/13,the inflow state of the sluice is further optimized. |
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