Research On The Underset Energy Dissipation Of The Release Works In Xianmi Hydropower Station

The research is according to the underset energy dissipation problem of the release works in xianmi hydropower station in Xianmi village, Men Yuan county, Qinghai province. So as to validate the release capacity of the flood discharge silt sluice , overfall weir, overfall dam and so on when they operate individually or gate lifting or operate associating with others;Observe the waterflow patterns, water surface profile, pressure and velocity of flow distributing of the plunge pool under different conditions;Observe erosion shape of the backward position riverbed, and have a optimization research on release works shape.Based on the experimental research, the flow rate of the original design project is satisfied, but the design for the inlet sect ellipse curve of the flood discharge silt sluice and the shape of the plunge pool is illogicality, and the problem of the plunge pool is very extrude.Traditional underset hydraulic jump energy dissipation method can not solve the energy dissipation problem of the plunge pool.Based on plenty of experimental research and comparing many projects, use aerated flow splitting pier and plunge pool to solve the underset energy dissipation problem. Study the flow expansion character, the pressure on the jets impact spot, constriction ratio and applicationconditions of the aerated flow splitting pier. According to the project conditions of the xianmi hydropower station, a aerated flow splitting pier is set on the upstream of the flood discharge silt sluice, two aerated flow splitting piers are set on every hole of the overfall weir steep slope. The aerated flow splitting pier is applied for overfall dam and the flood discharge silt sluice first time, expands the scope of application for aerated flow splitting pier. The experiment prove that the application of aerated flow splitting pier and plunge pool,solve effectively underset energy dissipation problem of the release works in xianmi hydropower station,and shorten the length of the overfall weir plunge pool by 25m,the water deep shorten by 1.0m,play down the cost of project greatly.According to the erode condition of the backward poison riverbed, we research the disposed manner of the plunge pool diversion wall, the shape of the T-frusta and the disposed manner in the flood discharge silt sluice plunge pool.Recommende this disposed manner which improve the waterflow patterns of backward poison riverbed, make the deep of rush hole and range decrease greatly, and make the negative pressure on the T-frusta disappeare.Some Experiments have been researched, Such as whirl vortex in right diversion wall infront of discharge silt sluice, overfall dam plunge pool and discharge silt sluice, the protect and the stability of splitting pier and recommende some measures in project.Advance the application way of release works based on the experiment to the manage departments.