A wing-shaped stilling pool

Abstract

An airfoil-shaped energy dissipation basin comprises a conventional section, a narrowed section located downstream of the conventional section and having a narrowed flow cross section, and an airfoil-shaped structure located at the head of the upstream narrowed section and diffusing toward the outside of the flow channel; the airfoil-shaped structure comprises a narrowed portion and a diffusing portion. The present invention provides an additional energy dissipation site for part of the water body by adding airfoil-shaped structures on both sides of appropriate positions in the middle of a conventional energy dissipation basin, so that the part of the water body forms a strong swirl in the diffusion part space, thereby realizing a large dissipation of energy, and greatly increasing the energy dissipation efficiency of the conventional energy dissipation basin. In addition, the present invention has a simple structure, does not significantly increase the amount of engineering, has an outstanding energy dissipation effect, and has a great application value.

Description

Technical Field

[0001] The invention relates to the field of flood discharge and energy dissipation in water conservancy and hydropower engineering, in particular to a wing-shaped energy dissipation pool. Background Art

[0002] In the construction of water conservancy and hydropower projects, the main hydraulic design task of the discharge structure is to select appropriate energy dissipation measures (in water conservancy projects, the water level of the river channel is raised due to dams, weirs and other water-blocking structures. The discharge of water will inevitably lead to a significant increase in flow velocity. The connotation of energy dissipation is to make a part of the huge kinetic energy carried by the high-speed water flow quickly converted into potential energy again, thereby reducing the flow velocity of the water flow) so as to eliminate the residual energy of the high-speed water body relative to the downstream river channel within a shorter distance downstream, so as to smoothly connect with it. Bottom flow energy dissipation is the so-called energy dissipation of the energy dissipation pool, which is to use the artificial construction of the energy dissipation pool to quickly transform the high-speed water flow from a rapid flow to a slow flow state, thereby avoiding the scouring and damage of the downstream river channel by the high-speed water flow. Bottom flow energy dissipation is generally recognized and adopted by the engineering community due to its outstanding advantages such as simple structure and smooth water flow out of the pool. Its energy dissipation mechanism is to use the strong tumbling and large amount of aeration caused by the water jump caused by the transition from rapid flow to slow flow to dissipate energy. Its typical layout is as follows Figure 1 shown.

[0003] At present, the conventional design of the stilling pool is that the inlet width of the water flow entering the stilling pool is basically the same as the outlet width of the water flow leaving the stilling pool. In order to prevent the scouring damage of high-speed water flow, the bottom plate of the stilling pool generally needs to be made very thick, and the protection section is also required to be made longer. In order to minimize the length of the stilling pool and the engineering cost of its downstream connection section, the current engineering often adopts the use of auxiliary facilities such as stilling piers (teeth) at appropriate positions inside the stilling pool to achieve the purpose of strengthening water turbulence and enhancing water flow energy dissipation. At the same time, the energy dissipation pier also produces a reverse force on the oncoming water body, thereby reducing the depth and length of the stilling pool. However, engineering practice has proved that when the flow rate is high, the side walls of the auxiliary facilities are very likely to produce local negative pressure, resulting in cavitation damage; at the same time, for rivers with floating objects (such as drift wood, drift ice, etc.) and bedload, the auxiliary energy dissipation facilities are often violently impacted and damaged.

[0004] In addition, model tests and engineering practice have proved that the energy dissipation rate of conventional stilling pools is relatively low, generally around 60% to 70%, and sometimes even lower. In view of the insufficiency of the conventional hydraulic structure layout in the prior art, it is necessary to change the design ideas, and by changing the layout of hydraulic structures, it is possible to fully utilize the advantages of the existing stilling pools and overcome the disadvantages of the low energy dissipation rate of the existing stilling pools as much as possible. Summary of the invention

[0005] In view of the above problems, the present invention proposes a wing-shaped energy dissipation pool, which can fully utilize the advantages of existing energy dissipation pools and overcome the disadvantages of low energy dissipation rate of existing energy dissipation pools as much as possible, while significantly improving the energy dissipation efficiency without significantly increasing the engineering workload.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] An airfoil stilling basin comprises a conventional section, a narrow section located downstream of the conventional section and having a narrowed flow section, and an airfoil structure located at the upstream head of the narrow section and diffusing toward the outside of the flow channel; the airfoil structure comprises a narrow part and a diffusing part.

[0008] Furthermore, the width of the narrow part of the airfoil structure is 2 =(0.05~0.20)B, where B is the inlet width of the stilling basin; the width of the diffuser part of the airfoil structure a 1 =(1.0~2.0)a 2 , diffusion length b = (1.0 ~ 3.5) a 1 .

[0009] Furthermore, the length of the diffusion part of the stilling basin airfoil structure is b<0.2L, where L is the length of the stilling basin.

[0010] Furthermore, the water-facing surface of the narrowed portion of the airfoil structure forms an acute angle θ with the water flow direction, and θ is preferably 20° to 70°.

[0011] Furthermore, the side wall of the water-facing surface of the narrowed portion is a rounded structure.

[0012] Furthermore, multi-stage beam narrowing sections and airfoil structures are symmetrically arranged on both sides of the stilling basin.

[0013] The present invention proposes a wing-shaped energy dissipation pool, which provides an additional energy dissipation site for part of the water body by adding wing-shaped structures on both sides of appropriate positions in the middle of the conventional energy dissipation pool, so that the water body forms a strong swirl in the diffusion part space, thereby realizing a large dissipation of energy, and greatly increasing the energy dissipation efficiency of the conventional energy dissipation pool. In addition, the structure is simple in shape, does not greatly increase the amount of engineering, has an outstanding energy dissipation effect, and has great application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of a conventional stilling pool.

[0015] Figure 2 This is a schematic diagram of an airfoil stilling basin provided in Embodiment 1 of the present invention.

[0016] Figure 3 This is a schematic diagram of an airfoil stilling basin provided in the second embodiment of the present invention.

[0017] Figure 4 This is a flow diagram of an airfoil stilling basin provided in the second embodiment of the present invention.

[0018] Figure 5 This is a schematic diagram of a two-stage wing-shaped stilling basin provided in Embodiment 3 of the present invention.

[0019] Among them: energy dissipation basin 1, tail sill 2, conventional section 3, narrow section 4, airfoil structure 5, narrow part 6, side wall 7, diffuser part 8; arrows indicate the direction of water flow. DETAILED DESCRIPTION

[0020] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0021] Embodiment 1

[0022] Embodiment 1 of the present invention provides an airfoil stilling pool, such as Figure 2 shown.

[0023] An airfoil stilling basin comprises a conventional section 3, a narrow section 4, and an airfoil structure 5. The airfoil structure 5 comprises a narrow portion 6 and a diffuser portion 8.

[0024] use Figure 2 In the manner shown, a conventional rectangular stilling basin is narrowed at an appropriate position toward the inside of the stilling basin, so that the flow cross section becomes narrower and a narrow section 4 is formed; at the same time, the upstream head position of the narrow section 4 is diffused toward the outside of the flow channel to form an additional energy dissipation airfoil structure 5.

[0025] Due to the existence of the diffusion part in front of the narrow part, the water flow opposite to the narrow part 6 flows along the diffusion part 8. Due to the restraining effect of the boundary, the water body produces a strong swirl inside the diffusion part, thereby achieving a large dissipation of energy, greatly increasing the energy dissipation efficiency of the stilling pool.

[0026] Since the narrowing of the side wall 7 makes the outlet width of the stilling pool narrower, the water depth in the stilling pool increases, so the height of the tail sill 2 of the stilling pool can be appropriately lowered during design.

[0027] The width of the narrow part of the airfoil structure is a 2 Determines the volume of water entering the diffusion space for energy dissipation, but a 2 If it is too large, the outlet width of the stilling pool will be too small, thus affecting its flow capacity, and eventually making the water depth in the stilling pool too large and the side walls of the stilling pool too high, which should undoubtedly be avoided. 2 =(0.05~0.20)B, where B is the inlet width of the energy dissipation pool.

[0028] Diffusion part width a 1 The energy dissipation efficiency of the diffuser is largely determined by the energy dissipation of the water flow introduced from the narrow part. It needs to be adequately dissipated and should also be reasonably selected based on economic efficiency. Generally, a 1 =(1.0~2.0)a 2 .

[0029] The length b of the diffusion part is also an important factor affecting the energy dissipation efficiency of the structure. Its size needs to be sufficient to form a vortex with a good shape inside the diffusion part 8, that is, there will be no excessive water surface stagnation. Generally, b = (1.0 ~ 3.5)a 1 At the same time, considering the engineering investment, b cannot be too large, that is, b<0.2L (L is the length of the stilling pool).

[0030] Embodiment 2

[0031] The second embodiment of the present invention proposes that, in order to allow the water in the narrow part to smoothly enter the diffusion part 8 and better form the energy dissipation swirl, the water-facing surface at the beginning of the narrow part 6 can be set to form a certain acute angle θ (i.e. less than 90°) with the water flow direction. Generally, θ can be taken as 20° to 70°; at the same time, in order to avoid the phenomenon of water flow shedding caused by too strong sharp edges, the sharp edges in the structure can be rounded. Figure 3 Its typical flow pattern is as shown in Figure 4 shown.

[0032] Embodiment 3

[0033] At the same time, in order to further eliminate energy, the third embodiment of the present invention proposes that the airfoil structure can be symmetrically arranged in multiple stages on both sides of the stilling pool, such as Figure 4 A schematic diagram of a two-level structure.

[0034] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A wing-shaped energy dissipation pool, characterized in that: It comprises a conventional section (3), a narrow section (4) located downstream of the conventional section (3) and having a narrowed flow cross section, and an airfoil structure (5) located at the upstream head of the narrow section (4) and diffusing toward the outside of the flow channel; the airfoil structure (5) comprises a narrow portion (6) and a diffusing portion (8); The width of the narrow part of the airfoil structure (5) is a2 = (0.05-0.20) B, where B is the width of the stilling basin inlet; The diffusion part width a1 of the airfoil structure (5) is equal to (1.0 to 2.0) a2, and the diffusion part length b is equal to (1.0 to 3.5) a1; The diffusion part length b of the stilling basin airfoil structure (5) is less than 0.2L, where L is the length of the stilling basin; The water-facing surface of the narrowed portion (6) of the airfoil structure (5) forms an acute angle θ with the water flow direction, and θ is 20° to 70°.

2. The wing-shaped energy dissipation basin according to claim 1, characterized in that: The water-facing side wall of the narrowed portion (6) is a rounded structure.

3. The airfoil stilling basin according to claim 1, characterized in that: Multi-stage beam narrowing sections (4) and airfoil structures (5) are symmetrically arranged on both sides of the stilling basin.

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