CN201254714Y - Suddenly enlarged and drop sill type underflow energy dissipating work structure - Google Patents

Abstract

The utility model relates to a sudden enlargement drop-sill underflow energy dissipater structure, which provides a falling-sill with a certain vertical height downwards from a base plate at the end of a spillway of a stilling basin, the sudden enlargement with a certain distance is arranged on a horizontal direction of a side wall. After an incoming main flow moves a certain distance in energy dissipation water and obtains certain diffusion, the main flow can just reaches the base plate and the side wall, the incoming main flow directly impacting the base plate and the side wall is avoided. So compared with a traditional underflow energy dissipater, hydraulic indexes of the base plate and the side wall are decreased greatly, the stability of the base plate and the side wall is increased, the hydraulic indexes of the stilling basin base plate and the side wall can be decreased effectively, the efficiency is increased greatly, and the utility model has the advantages that atomization is lower, the flow state is stable and the like.

Description

Sudden expansion and drop sill type bottom flow energy dissipation structure

technical field

The utility model relates to a sudden expansion and drop sill type bottom flow energy dissipation structure, which can solve the problem of flood discharge and energy dissipation in projects with high water head, large single width flow rate and strict requirements on atomization.

Background technique

As we all know, the traditional bottom current energy dissipator is an energy dissipation method that utilizes the hydraulic jump generated in the stilling pool to dissipate energy. The main characteristics of bottom flow energy dissipation are that the jet flow is close to the bottom, the bottom flow velocity is very high, there are milky white swirls on the surface of the water flow, and a large amount of aeration. In the hydraulic jump zone, the jet exchanges mass, momentum and energy with the surrounding water body through turbulence, diffusion and mixing to achieve the purpose of energy dissipation. With the continuous increase of high-head discharge structures, although the number of underflow energy dissipation devices used for high-head flood discharge has increased, it is still a minority compared with deflected flow energy dissipation. The reason is that the traditional underflow energy dissipation is used. However, compared with deflector flow energy dissipaters, the flood discharge fog caused by bottom flow energy dissipaters The change is very small, and the impact on the surrounding environment is small. With the continuous improvement of national environmental awareness, the application of underflow energy dissipation in high dams and large flow projects is an urgent research topic.

Contents of the invention

In order to overcome the problems that the traditional bottom flow energy dissipator is used in high-head discharge buildings, the hydraulic index of the stilling pool and the side wall are relatively high, and the anti-scour protection is difficult. The utility model provides a sudden expansion Falling sill type bottom flow energy dissipator structure, this new type of energy dissipator structure can not only reduce the hydraulic index of the bottom and side walls of the stilling pool, but also has the advantages of high energy dissipation rate and stable downstream flow state.

The technical solution adopted by the utility model to solve the technical problem is: the sudden expansion and drop sill type bottom flow energy dissipation structure is based on the three-dimensional hydraulic jump energy dissipation mechanism in space and the submerged jet energy dissipation mechanism, and the stilling pool at the end of the chute The bottom plate is excavated downward to a certain vertical height to form a sill and the side wall expands a certain distance in the horizontal direction to form a sudden expansion, so that the high-speed water flow discharged into the middle of the energy dissipation water body forms a strong shear layer and a strong vortex around the main flow. Rolling and mixing to achieve the purpose of energy dissipation.

In the utility model, since the jet flow discharged from the chute enters the stilling pool, there is a certain vertical and horizontal distance from the bottom plate and the side wall, and the main flow entering the pool moves for a certain distance in the energy-dissipating water body before reaching the bottom plate and the side wall. , avoiding the direct impact of the mainstream entering the pool on the bottom plate and side walls, so compared with the traditional bottom flow energy dissipator, the hydraulic index at the bottom plate and side walls is greatly reduced, and the stability of the bottom plate and side walls is increased.

The beneficial effects of the utility model are: the hydraulic index at the bottom plate and the side wall of the stilling pool can be effectively reduced, the efficiency rate is greatly improved, and the utility model has the advantages of low atomization and stable flow state.

Description of drawings

The utility model is further described below in conjunction with the accompanying drawings, but the structure of the utility model is not limited to those shown in the accompanying drawings.

Fig. 1 is a schematic plan view of the body shape of the utility model.

Fig. 2 is a schematic diagram of a body elevation of the utility model.

Detailed ways

In Figure 1 and Figure 2, 1 is the chute, 2 is the expansion distance of the side wall, 3 is the stilling tank, 4 is the end of the stilling tank, 5 is the tail water section, 6 is the angle of entering the pool, and 7 is the falling sill.

The water flow into the pool enters the stilling pool 3 along the chute 1 or the overflow dam. Due to the existence of the sudden expansion of the side wall expansion distance 2, the water flow enters the middle of the energy-dissipating water body, and the water flow into the pool and the surrounding still water body produce a rapid interruption. According to turbulence mechanics, the velocity discontinuity surface is unstable, and it will inevitably produce fluctuations and develop into vortices, which will cause turbulence, mixing parameters, momentum and mass exchange, and consume a lot of energy. Due to the existence of the falling ridge 7, the mainstream avoids directly impacting the bottom plate of the stilling pool 3 after entering the stilling pool 3, and only reaches the bottom plate after consuming a part of energy along the way, so the hydraulic index of the bottom plate of the stilling pool 3 is much lower. When the water flows out of the 4 sills at the end of the stilling pool, the energy is greatly reduced, the flow state is stable, and the atomization is low.

Claims (1)

1. An underflow energy dissipator structure with sudden expansion and drop sill, characterized in that: there is a drop sill of a certain vertical height downward on the bottom plate of the stilling pool (3) at the end of the chute (1), and there is a drop sill in the horizontal direction of the side wall Sudden expansion at a certain distance.

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