Test Study On Layout Project Of Flood Discharge And Desilting Building For Tailan River Hydropower Station

There is a outstanding antinomy between divert water and sediment prevention in thelow head sluice dam hydro-electric station which on the heavily silt-carrying river.Its layoutproject of flood discharge and desilting building and project scheduling whether reasonableaffects its flood discharge and desilting directly. So its necessary to optimize the layoutproject of flood discharge and desilting building and project scheduling.Based on the study of Tailan river hydropower station, to find out the problem in originaldesign through the model test and suggested correction of it. Through practice certificationtests for best project. In order to solve the problem of sediment, the sedimentation experimentwas made. Through cost effective solutions and work in with condition of engineering,thequote water have met the design requirement.The results of this test show that：(1) In the original design,the discharge capacity of scouring sluice is too large(more than19%of design value) and the discharge capacity of sluice is insufficient(47.9m3/s in normalwater level and design value is56m3/s);The flow regime in lock chamber and before openinggates is disorder and water-wing appears in the end of gate pier,these lead the reflexion andscour flow appear in protection-apron and apron. These endangers the safety of dam.In thecorrected design,the number of opening gate of scouring sluice from6to5, the dischargecapacity of scouring sluice is1424.1m3/s in check water level.It is close to the design valuewhich is1433.2m3/s; The discharge capacity of sluice is56.18m3/s.It reach the design valuewhich is56m3/s; Every adverse flow regime is eliminated due to the elevation of water guidewall upstream was raised to1655.7m and add low pier in the end of lock chamber.(2)In the original design, the absorption basin on the downstream of flushing sluice androw of floating gates do not dissipate energy. There is a serious scour in the end of apron andthe right side of bank slope because of lack of energy dissipater. In the corrected design,to addreinforcing gabions in the end of apron is an effectual preventive for scour.(3) In the original design, there is no effective means of sediment discharged,so thelength of sand flushing funnel along a longitudinal length is too short.It lead to the sedimentdeposition in front of sluice. In the corrected design, to add water&sand guide wall is aneffectual preventive for sediment deposition. Sediment deposition results are perfect by using three prevention measures and the water&sand guide wall.(4) Using Flow3D software to simulate is an effective means to test the dischargecapacity of scouring sluice. This method is effective and reliable and can be use to reduce theworkload of physical model.