CN208219577U - Vertical shaft eddy flow bottom baffle box - Google Patents

Abstract

The utility model provides a kind of vertical shaft eddy flow bottom baffle box, including vertical shaft, energy dissipating well, it further include first of baffle wall style and second baffle wall style, energy dissipating well, first of baffle wall style and second baffle wall style are successively set in water-break hole along water (flow) direction, silo bottom is communicated with water-break hole, the energy dissipating well location is immediately below the vertical shaft, and the top of energy dissipating well is concordant with water-break hole bottom plate and the two communicates, and energy dissipating well is reverse frustoconic and concentric with vertical shaft.This vertical shaft eddy flow bottom baffle box, energy dissipating well are in reverse frustoconic, can effectively disperse the impact force of vertical shaft water flow, and first of baffle wall style can increase the depth of water before bank, reduce vertical shaft water flow to the fluctuation pressure and impact force of bank noseplate；Second baffle wall style can further improve energy dissipation rate, connect vertical shaft water flow smoothly with water-break hole water flow.Its figure is simple, is easy to construct, either high water level or low water level, can form stable submerged hydraulic jump, and water level fluctuation is small, and water flow aeration is abundant, it is downstream atomizing it is small, energy dissipation rate is high.

Description

Vertical shaft swirl bottom energy dissipation box

technical field

The utility model belongs to the technical field of water flow energy dissipation, in particular to an energy dissipation box at the bottom of a vertical shaft swirling flow.

Background technique

In recent years, in order to reduce the cost of the project, many projects have converted the diversion tunnel into a permanent flood discharge tunnel. Among them, the swirl type internal energy dissipation device can be used to simplify the lining project, reduce the project cost, speed up the construction progress, and reduce the erosion and erosion of the tunnel exit. The atomization phenomenon is a new type of energy dissipation measure suitable for high water head and large flow in deep mountains and valleys, and it is a feasible solution for diversion tunnels in high dam construction to be transformed into flood discharge tunnels. Swirling flood discharge tunnels can be divided into vertical shaft swirling energy dissipation and horizontal swirling energy dissipation according to the location where the swirling water flow occurs. The principle is to use the centrifugal force of swirling water flow to form a cavity, increase the wall pressure and hydraulic friction, and prolong the life of the tunnel. process to achieve the purpose of preventing cavitation and energy dissipation.

The energy dissipation of vertical shaft swirl usually depends mainly on the water cushion at the bottom and the rotating energy dissipation of water flow in the shaft. When the water depth at the bottom of the shaft increases, the impact pressure of the water flow on the bottom of the shaft decreases, and the energy dissipation rate decreases. When the water depth at the bottom of the shaft is shallow , the energy dissipation rate increases, but the impact pressure of the water flow on the bottom of the shaft increases. In order to make the water flow smoothly transition from the shaft swirl to the retreat tunnel, it is usually necessary to renovate the connecting section between the retreat tunnel and the shaft to form a local short pressurized flow, and the modified section is longer and more complex in shape.

Utility model content

The purpose of the utility model is to provide an energy-dissipating box at the bottom of the vertical shaft swirl, which can reduce the flow velocity of the water-retreating tunnel, improve the energy-dissipating rate, and reduce the construction difficulty and engineering quantity.

The technical scheme of the utility model is as follows:

The energy dissipation box at the bottom of the vertical shaft swirl includes the vertical shaft, the energy dissipation well, and also includes the first and second force dissipation sills, and the energy dissipation well, the first energy dissipation sill and the second energy dissipation sill They are sequentially arranged in the water-retreating tunnel along the water flow direction, the bottom of the vertical shaft communicates with the water-retreating tunnel, the energy-dissipating well is located directly below the vertical shaft, the top of the energy-dissipating well is flush with the bottom plate of the water-retreating tunnel, and the two communicate with each other. The energy dissipation shaft is in the shape of a round frustum and is concentric with the vertical shaft.

The first stilling sill is higher than the second stilling sill, the longitudinal sections of the first stilling sill and the second stilling sill are right-angled trapezoids, and the first stilling sill and the second stilling sill The vertical sides of the two stilling sills are facing the water, and the slopes are all facing the water, and the slope of the slope is 1:2.

The shaft diameter , where: μ=1~1.25, Q _m is the maximum discharge capacity of the shaft swirl hole, m ³ /s; g is the acceleration of gravity.

The top diameter of the energy dissipation well is 1.8 times to 0.9 times the width of the drain hole 5, the bottom diameter is 1.1 to 1.3 times the diameter of the shaft, and the height of the energy dissipation well is 6m to 10m.

The height of the first stilling sill is 0.4 to 0.6 times the total height of the retreating tunnel, the width is equal to that of the retreating tunnel, and the top width is 1m;

The height of the second stilling sill is 0.3 to 0.4 times the height of the first stilling sill, the width is equal to that of the retreating water tunnel, and the top width is 1m.

The energy-dissipating well, the vertical shaft, the first stilling sill, the second stilling sill, and the drainage tunnel are all reinforced concrete structures.

The beneficial effects of the utility model are:

The energy-dissipating box at the bottom of the swirling shaft provided by the utility model has an energy-dissipating well in the shape of a rounded table, which can effectively disperse the impact force of the water flow in the shaft. The first sill can increase the water depth in front of the sill and reduce the water flow in the shaft The pulsating pressure and impact force on the bottom plate in front of the sill; the second stilling sill can further improve the energy dissipation rate, so that the water flow of the shaft and the water flow of the retreat tunnel can be smoothly connected.

Its shape is simple and easy to construct. Whether it is high water level or low water level, a stable submerged jump can be formed in front of the two stilling sills, and it has the advantages of small water surface fluctuation, sufficient aeration of water flow, small downstream atomization, and high energy dissipation rate. features.

Further details will be described below in conjunction with the accompanying drawings.

Description of drawings

Fig. 1 is a side view of the energy dissipation box at the bottom of the vertical shaft swirl of the present invention;

Fig. 2 is a top view of the energy dissipation box at the bottom of the shaft swirl of the utility model;

Fig. 3 is a downstream vertical view of the energy dissipation box at the bottom of the swirling flow in the shaft of the utility model.

In the figure: 1. Energy dissipation well; 2. Shaft; 3. The first stilling sill; 4. The second stilling sill; 5. Retreating water tunnel.

Detailed ways

Example 1:

This embodiment 1 provides an energy dissipation box at the bottom of a vertical shaft swirl flow, including a vertical shaft 2, an energy dissipation well 1, and a first dam 3 and a second dam 4. The energy dissipation well 1, The first stilling sill 3 and the second stilling sill 4 are sequentially arranged in the water retreat tunnel 5 along the water flow direction, the bottom of the shaft 2 communicates with the water retreat tunnel 5, and the energy dissipation well 1 is located below the shaft 2, The top of the energy-dissipating well 1 is flush with the bottom plate of the drain hole 5 and communicated with the two.

The water flows from the shaft 2 into the water retreating tunnel 5, and then into the energy dissipation well 1, through the rounded frustum-shaped energy dissipation well 1 to effectively disperse the impact force of the water flow in the shaft 2, and then through the first stilling ridge 3 to increase the water depth in front of the ridge , reduce the pulsating pressure and impact force of the shaft water flow on the bottom plate in front of the sill, and finally further improve the energy dissipation rate through the second stilling sill 4, so that the water flow of the shaft 2 and the water flow of the retreat tunnel 5 are smoothly connected.

The energy dissipation box at the bottom of the vertical shaft swirl provided in Example 1 can form a stable submerged hydraulic jump before the first and second stilling sills, regardless of whether it is a high water level or a low water level, and has small water surface fluctuations and low operating water head. Wide range and high energy dissipation rate.

Example 2:

On the basis of Embodiment 1, this embodiment provides a vertical shaft swirl bottom energy dissipation box as shown in Fig. 1, Fig. 2 and Fig. 3, and the first dam 3 is higher than the second dam force sill 4, the longitudinal sections of the first slack sill 3 and the second slack sill 4 are right-angled trapezoidal, and the vertical sides of the first slack 3 and the second slack 4 are both It is facing the water, and the slopes are all facing the water, and the slope of the slope is 1:2.

Wherein, the diameter of the shaft 2 , where: μ=1~1.25, Q _m is the maximum discharge capacity of the shaft swirl hole, m ³ /s; g is the acceleration of gravity.

The top diameter of the energy dissipation well 1 is 1.8 times to 0.9 times the width of the vertical shaft 2 to 0.9 times the width of the water retreat tunnel 5, the bottom diameter is 1.1 to 1.3 times the diameter of the vertical shaft 2, and the height of the energy dissipation well 1 is 6m~ 10m.

The height of the first stilling ridge 3 is 0.4 to 0.6 times the total height of the retreating tunnel 5, the width is equal to that of the retreating tunnel 5, and the top width is 1m;

The height of the second stilling sill 4 is 0.3 to 0.4 times the height of the first stilling sill 3, the width is equal to that of the retreating tunnel 5, and the top width is 1m.

The energy dissipation well 1, the vertical shaft 2, the first stilling sill 3, the second stilling sill 4, and the drainage tunnel 5 are all reinforced concrete structures.

Wherein, the width of the retreating tunnel 5 refers to the width of one side perpendicular to the water flow direction (in the horizontal direction). The length of the upper base of a right-angled trapezoid in section.

To sum up, in the energy dissipation box at the bottom of the swirling shaft provided by the utility model, the energy dissipation well 1 is in the shape of a rounded table, which can effectively disperse the impact force of the water flow in the shaft 2, and the first dam 3 can increase the The water depth in front reduces the pulsating pressure and impact force of the shaft water flow on the bottom plate in front of the sill; the second stilling sill 4 can further increase the energy dissipation rate, so that the water flow of the shaft 2 and the water flow of the retreat tunnel 5 are smoothly connected.

It has a simple shape and is easy to construct. Whether it is a high water level or a low water level, a submerged hydraulic jump can be formed in front of the first stilling sill 3 and the second stilling sill 4, and the root mean square value of the water flow fluctuation pressure is less than 60kPa. It has the characteristics of small water surface fluctuation, sufficient aeration of water flow, small downstream atomization and high energy dissipation rate.

The above examples are only illustrations of the present utility model, and do not constitute a limitation to the protection scope of the present utility model. All designs identical or similar to the present utility model belong to the protection scope of the present invention. The parts not specifically described in this embodiment belong to common knowledge and technologies in the technical field, and will not be described in detail here.

Claims (6)

1. The energy dissipation box at the bottom of the vertical shaft swirl, including the vertical shaft (2), the energy dissipation well (1), the first stilling sill (3) and the second stilling sill (4), characterized in that: the The energy well (1), the first stilling sill (3) and the second stilling sill (4) are sequentially arranged in the water retreat tunnel (5) along the water flow direction, and the bottom of the vertical shaft (2) and the water retreat tunnel (5) connected, the energy dissipation well (1) is located directly below the vertical shaft (2), the top of the energy dissipation well (1) is flush with the bottom plate of the water retreat tunnel (5) and the two are connected, the energy dissipation The well (1) is rounded and concentric with the shaft (2). 2. The energy dissipation box at the bottom of the shaft swirling flow according to claim 1, characterized in that: the first silencing sill (3) is higher than the second silencing sill (4), and the first silencing sill (3) The vertical sections of the force sill (3) and the second sill (4) are both right-angled trapezoidal, and the upright sides of the first sill (3) and the second sill (4) are facing The water surface and the slope are both the backwater surface, and the slope of the slope is 1:2. 3. The vertical shaft swirl bottom energy dissipation box according to claim 1, characterized in that: the diameter of the vertical shaft (2) , where: μ=1~1.25, Q _m is the maximum discharge capacity of the vertical shaft swirl hole, m ³ /s; g is the acceleration of gravity. 4. The energy dissipation box at the bottom of the shaft swirling flow according to any one of claims 1-3, characterized in that: the diameter of the top of the energy dissipation well (1) is 1.8 times the diameter of the shaft (2) ~ the receding hole (5) 0.9 times the width, the bottom diameter is 1.1 to 1.3 times the diameter of the shaft (2), and the height of the energy dissipation well (1) is 6m to 10m. 5. The energy dissipation box at the bottom of the shaft swirling flow according to claim 4, characterized in that: the height of the first stilling sill (3) is 0.4 to 0.6 times the total height of the water retreat tunnel (5), The width is equal to that of the retreating tunnel (5), and the top width is 1m; The height of the second stilling sill (4) is 0.3 to 0.4 times the height of the first stilling sill (3), the width is equal to that of the retreating tunnel (5), and the top width is 1m. 6. The energy dissipation box at the bottom of the shaft swirling flow according to claim 1, characterized in that: the energy dissipation well (1), the vertical shaft (2), the first dam (3), and the second silencing The ridge (4) and the retreat tunnel (5) are all reinforced concrete structures.