CN103266584B - A kind of hydraulic engineering energy dissipating construction - Google Patents

Abstract

The utility model relates to a water conservancy project energy dissipator structure, which relates to the structure type of the water conservancy project energy dissipator. It sets up a ridge behind the gate pier, the rear end of the ridge is connected to the stilling pool, and the stilling ridge is set at the end of the stilling pool. The key technology is that the facing surface of the ridge is a slope, the top of the facing surface is folded inward to form a ridge angle, the angle between the top of the facing surface and the horizontal plane forms a ridge angle α ₁ , and there is an inclined surface outside the top of the ridge to form a diffuse shape. Falling sill; there is a slope at the end of the stilling sill, and the angle between the slope and the bottom plate of the stilling pool forms an α ₂ angle. The beneficial effects of the present invention are as follows: a ridge is set behind the sluice pier, and the upper end of the ridge facing the water is folded inward to form a ridge; The water tongue, after passing through the diffuse shape and falling ridge, the water tongue in the pool diffuses to the entire section of the stilling pool, and enters the stilling pool with a small single-width flow rate, forming a submerged water jump in the pool, and the water flow out of the pool is slow, and the water surface is stable. The tail water is naturally connected.

Description

A water conservancy project energy dissipator structure

Technical field:

The utility model relates to a water conservancy project energy dissipator structure, which relates to the structure type of the water conservancy project energy dissipator.

Background technique:

The construction of hydropower stations in the middle and lower reaches of the river is often limited by the terrain conditions of the dam site and the width of the flood discharge flow. The single-width discharge of the flood gate is large and the water head is relatively low. These conditions make the problem of flood discharge and energy dissipation one of the controlling factors for the layout of the project hub. Most of these discharge structures have the characteristics of low water head, large single-width flow rate, low Froude number, deep tail water, and large fluctuation of downstream water level drop. In addition, it can also be seen from the construction cost that energy dissipation and anti-scour facilities account for quite a large proportion. Therefore, the form and rational arrangement of the drainage structures become a restrictive and important technical problem.

Invention content:

The problem to be solved by the present invention is to provide a structural type of energy dissipator for flood discharge and energy dissipation of water conservancy projects with low water head and large flow in view of the above deficiencies. Its technical scheme is as follows:

It sets up a ridge behind the gate pier, the rear end of the ridge is connected to the stilling pool, and the stilling ridge is set at the end of the stilling pool. The key technology is that the facing surface of the ridge is a slope, the top of the facing surface is folded inward to form a ridge angle, the angle between the top of the facing surface and the horizontal plane forms a ridge angle α ₁ , and there is an inclined surface outside the top of the ridge to form a diffuse shape. Falling sill; there is a slope at the end of the stilling sill, and the angle between the slope and the bottom plate of the stilling pool forms an α ₂ angle.

Compared with prior art, the beneficial effect that the present invention has is:

1. Set up a pick-up ridge behind the sluice pier, and the upper end of the pick-up ridge is folded inward to form a pick-up angle. The drop ridge is a diffuse shape. When the discharge volume is small and the downstream tail water level is low, the water flows out of the sluice chamber through The ridge is lifted to form a horizontal diffusion water tongue, and after the diffuse shape falls, the water tongue into the pool diffuses to the entire section of the stilling pool, and enters the stilling pool with a small single-width flow to form a hydraulic jump, similar to deflecting water to dissipate energy. According to the experimental research, the water tongue is nearly 180-degree fan-shaped. The middle part of the water tongue is thicker than the two sides, and the flow velocity is also larger than the two sides. The water inlet point is closer to the downstream than the diffuse water flow on both sides. There is backflow under the water layer, a submerged jump is formed in the pool, the water out of the pool is a slow flow, the water surface is stable, and it naturally connects with the downstream tail water.

2. With the increase of the discharge volume, the downstream water level rises, and the water flowing out of the gate is provoked and diffused through the ridge, and collides, surges, and aerates the water flow in the stilling pool, and produces lateral diffusion and shearing in the stilling pool , blending, preventing the formation of secondary hydraulic jump, strengthening the energy dissipation effect, converting part of the mechanical energy of the water flow into heat energy and dissipating it, reducing the flow rate of the water flow out of the pool, and making the flow rate distribution uniform. According to the observation of the model test, a complete submerged hydraulic jump is formed in the stilling pool, a small amount of air bubbles are precipitated on the surface of the water flowing out of the pool, and there is backflow under the water layer of the water tongue, and the backflow surges upward at the junction of the diffusion flow of each hole. There is a large amount of aeration, the water flowing out of the pool does not drop, the fluctuation is small, it is discharged smoothly, and it is naturally connected with the downstream tail water.

3. The main function of the pick angle is to make the water tongue stretch horizontally and shrink vertically when the discharge volume is small. After the water flows through the pick ridge, it enters the stilling pool with a small single-width flow to form a hydraulic jump. The hydraulic characteristics of the water flow into the stilling pool are changed, and the water flow enters the stilling pool in the form of a fan-shaped jet, so that the flow rate is uniform.

4. The function of the stilling tank is to ensure the formation of an appropriate water depth in the stilling tank under various working conditions, to reduce the low flow velocity, avoid the impact of the water tongue on the bottom of the stilling tank when the discharge is small, and satisfy the formation of submerged hydraulic jumps Due to the combined effect of conjugate conditions, the vortex structure formed by the water flow in the pool is complex, and the collision and mixing are severe, which enhances the energy dissipation effect and effectively solves the secondary drop problem when the water flows out of the stilling pool, thereby further reducing the impact of the water flow on the downstream river bed. scour.

5. The slope stilling sill is set at the end, which can adjust the flow velocity distribution of the water flow out of the pool, and at the same time change the hydraulic parameters in the stilling pool to a certain extent. Its energy dissipation effect is good, so the downstream flushing effect is good.

6. To sum up, the present invention provides a small pick-up angle, falling ridge, and shallow water for the problem of flood discharge and energy dissipation with the characteristics of low water head, large flow, low Floyd's number, deep tail water, and large fluctuation of downstream water level drop. The combination of pad stilling pool and energy dissipation has better solved the problems of conventional low-flow energy dissipation and unstable water flow in the stilling pool.

Description of drawings:

Fig. 1 is a schematic diagram of the structure of the present invention.

Detailed ways:

Referring to Fig. 1 , the present invention sets a pick-up 2 behind the gate pier 1, the rear end of the pick-up 2 connects to a stilling pool 5, and a stilling pool 7 is arranged at the end of the stilling pool 5. The key technology is that the facing surface of the ridge 2 is a slope surface, the top of the facing surface is folded inward to form a protruding angle 3, the angle between the top of the facing surface and the horizontal plane forms a ridge angle α ₁ , and there is an inclined surface outside the top of the ridge 2 to form a diffuser. The drop ridge 4 of body type; There is a slope 6 at the tail end of the stilling ridge 7, and the angle between the slope 6 and the 5 bottom plates of the stilling pool forms α ₂ angles.

The angle of the α ₁ angle is between 0° and 45°. Under the same hydrological conditions, the smaller the sill height d and the larger the sill angle α1, the lower the boundary water depth required when _a certain flow state of mixed flow occurs, but the influence of the sill height is greater than that of the sill angle, and generally it should be set as low as possible In order to ensure the occurrence of high-sequence flow regimes, the height of the ridge is calculated based on the average height of the river bed, and the ridge angle can be selected from 0° to 45°. Generally, the ridge angle should be proportional to the Froude number Fr, and the smaller the value of Fr, The smaller the ridge angle is, but generally it is better to choose a larger ridge angle.

The angle of the α ₂ angle is 30°-90°. To adjust the flow velocity distribution of the pool water flow.

Claims (1)

1. An energy dissipater structure for a water conservancy project, a ridge (2) is arranged behind the gate pier (1), the rear end of the ridge (2) is connected to a stilling pool (5), and a stilling pool (5) is installed at the end of the stilling pool (5) The ridge (7) is characterized in that the facing surface of the ridge (2) is a slope surface, the top of the facing surface is folded inward to form a sloping angle (3), and the angle between the top of the facing surface and the horizontal plane forms a ridge angle α ₁ , α ₁ Angle is 0 ° ~ 45 °, there is an inclined surface outside the top of the lifting ridge (2), forming a falling ridge (4) of diffuse shape; there is a slope (6) at the end of the stilling ridge (7), and the slope (6) and The included angle of the stilling pool (5) bottom plate forms α ₂ angles, and the angle of α ₂ angles is 30°～90°.