A kind of bottom flow energy dissipation device and design method of toe sill and drop sill stilling pool

Abstract

The invention relates to a toe sill and drop sill stilling pool type underflow energy dissipater and a design method. The toe sill and drop sill stilling pool type underflow energy dissipater comprises a toe sill arranged at the bottom end of the incoming-flow slope, a drop sill is connected with the lower portion of the toe sill, the downstream portion of the toe sill and the downstream portion of the drop sill are provided with a stilling pool, and the downstream portion of the stilling pool is provided with a weir for retaining water. The hydraulic jump is controlled by the toe sill, turbulent diffusion is enhanced, the energy dissipation rate is increased, the length of the stilling pool is shortened, the energy dissipater is adapted to tail water level changes, and the water flow can be uniformly distributed on the width of the stilling pool. Meanwhile, a contracted water flow channel is formed through the toe sill, it can be guaranteed that the sill face does not generate negative pressure, and the function of contracting the energy dissipater is achieved. A water cushion of a certain depth is formed through the drop sill, and on one hand, vortex close to the bottom can be avoided, or the vertical axis vortex intensity behind the toe sill can be greatly lowered; and on the other hand, cavitation damage of the high-speed water flow behind the toe sill to the stilling pool floor is avoided, and the flow speed close to the bottom of the stilling pool can be effectively lowered.

Description

technical field [0001] The invention relates to a bottom flow energy dissipation device and a design method of a toe sill and a sill stilling pool type, a hydraulic facility and a design method, and a discharge energy dissipation facility and a design method of a high dam of a reservoir. Background technique [0002] Underflow energy dissipation is one of the main methods for high dam flood discharge energy dissipation. Entering the 21st century, many high dams in my country have chosen the bottom flow energy dissipation method in order to reduce the impact of flood discharge atomization on bank slope vegetation or due to geological environmental problems under the concept of ecological environment friendliness. In order to solve the technical problem that the hydraulic index of the stilling basin near the bottom of the traditional underflow energy dissipation in the high dam is too high, causing the destruction of the stilling basin, in recent years, my country's hydraulic ...

AI Technical Summary

Problems solved by technology

[0005] There are common problems in the shapes of the energy dissipation workers of the falling sill and bottom flow. First, due to the design of the sudden expansion shape, there is a pressurized vortex in the stilling pool. This vortex is different from the free surface vortex that is common in hydraulic engineering. The vortex has strong strength, closed watershed, and low pressure at the singular point of the vortex center (even negative pressure), which will easily lead to abrasion and cavitation damage to the side wall and bottom plate of the stilling pool, and the project is more harmful

Second, in order to ensure that there is no backflow or swinging water flow in the stilling pool, there are many restrictions on gate scheduling, and there are relatively high requirements for flood discharge management in the later stage of the hydropower station

Third, the scale of the stilling pool is huge. For example, the length of the stilling pool of Xiangjiaba Hydropower Station reaches 220m, which is close to 1.4 times the height of the dam, which directly leads to a large investment

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