Symmetrical two-stage energy dissipation spillway

Abstract

The utility model belongs to the technical field of hydraulic engineering, and particularly relates to a symmetrical two-stage energy dissipation spillway which comprises an overflow weir, a drainage channel, a first-stage stilling pool, a stepped discharge chute, a second-stage stilling pool and a tail water channel. The two ends of the first-stage stilling pool are symmetrically provided with drainage channels, and the two ends of the drainage channels are connected with an overflow weir and the first-stage stilling pool; a plurality of rotary energy dissipation grooves are symmetrically formed in the inner wall of the drainage channel in the length direction, a stepped drainage groove is formed in the downstream side outlet dam face of the first-stage stilling pool, a second-stage stilling pool is arranged at the tail end of the stepped drainage groove, and a tail water channel is connected behind the second-stage stilling pool; water flow flows into the drainage channel from the overflow weirs at the two ends, flows through the rotary energy dissipation grooves in the side walls of the inclined drainage grooves to eliminate part of kinetic energy and then enters the first-stage stilling pool to conduct violent front face collision energy dissipation. The water flow with most kinetic energy eliminated in the first-stage stilling pool continues to flow into the stepped discharge chute, part of kinetic energy can be eliminated when the water flow flows through the stepped discharge chute, and finally, the water flow flows into the second-stage stilling pool, and most energy is eliminated in the second-stage stilling pool.

Description

Technical Field

[0001] This utility model belongs to the field of water conservancy engineering technology, specifically relating to a symmetrical two-stage energy dissipation spillway. Background Technology

[0002] To discharge excess water from reservoirs, prevent dam overflows and ensure project safety, and meet requirements for flood control, regulation, and ecological landscape, spillways are generally required in earth-rock dams or concrete dams with poor downstream riverbed geology. However, existing spillways are mostly located on both banks of the dam abutment (called bank spillways). The structural layout of bank spillways is often limited by the geology and topography of the banks, resulting in large excavation and backfilling volumes and significantly increased investment. Therefore, designing spillways on the dam body would overcome the disadvantages of bank spillways, such as large land occupation, extensive excavation, and high investment, while also creating a more accessible waterfront landscape and improving the aquatic ecosystem. However, the energy dissipation effect of spillways on the dam body is critical; otherwise, it could cause severe erosion damage to the downstream riverbed and riverbanks. Therefore, there is an urgent need for a spillway that can be installed on the dam body and has excellent energy dissipation capabilities. Utility Model Content

[0003] The purpose of this invention is to provide a symmetrical two-stage energy dissipation spillway to solve the problems existing in the prior art. To achieve the above-mentioned objective, the technical solution adopted by this invention is as follows:

[0004] A symmetrical two-stage energy dissipation spillway includes a left-right symmetrical overflow weir, a left-right symmetrical spillway, a primary stilling basin, and a stepped spillway; the spillway is symmetrically arranged at both ends of the primary stilling basin, and the stepped spillway is arranged on the downstream outlet dam face of the primary stilling basin.

[0005] Furthermore, it also includes a dam body, wherein the spillway and the primary stilling basin are provided in the upper middle part of the downstream dam face; the spillway has multiple swirling energy dissipation channels symmetrically arranged along the water flow direction on the water-facing sidewalls of the inner and outer sidewalls, and the number of swirling energy dissipation channels is selected according to the length, flow rate and velocity of the spillway; the dam body has a stepped spillway on the downstream dam face, and a secondary stilling basin is provided at the end of the stepped spillway, and the tailrace channel is connected to the secondary stilling basin.

[0006] Furthermore, the swirling energy dissipation channel includes a straight section at the water inlet and an arc section at the water outlet, with the channel width gradually decreasing from the water inlet to the water outlet to prevent cavitation damage.

[0007] Furthermore, the stepped spillway is provided with stepped energy dissipation steps along the water flow direction.

[0008] Furthermore, the drainage channel along the water flow direction is composed of an inclined side channel, a horizontal adjustment section and an inclined discharge channel in sequence. The drainage channel is connected to the overflow weir in front and the primary stilling basin in the rear. The outer wall within the area of ​​the inclined side channel turns 90° along a circular arc in the plane.

[0009] This utility model has the following beneficial effects: This spillway innovatively adopts a two-stage energy dissipation structure and four energy dissipation methods to eliminate the kinetic energy of high-speed water flow; the first-stage energy dissipation structure includes a symmetrical overflow weir, a symmetrical spillway, and a first-stage stilling basin. When the water flows through the swirling energy dissipation channels set in the side walls on both sides of the spillway, the swirling energy dissipation channels change the direction of the branch flow by diverting the flow, and cause the branch flow in the channel to collide with the original main flow in the spillway from the side to dissipate energy. Then, it continues to flow into the first-stage stilling basin along the symmetrical spillway and dissipates energy through violent head-on collision. Therefore, the first-stage energy dissipation structure mainly dissipates energy through two methods: side collision of the swirling energy dissipation channel and head-on collision of the first-stage stilling basin. The second-stage energy dissipation structure includes a stepped spillway at the outlet of the primary stilling basin, a secondary stilling basin, and a tailrace channel. As water flows across the stepped energy dissipation steps, a significant portion of its kinetic energy is lost. The water then flows into the secondary stilling basin, where it dissipates energy through bottom flow. Therefore, the second-stage energy dissipation structure primarily utilizes stepped energy dissipation and bottom flow energy dissipation. In summary, the energy dissipation effect of this symmetrical two-stage energy dissipation spillway is far superior to that of traditional spillways, effectively protecting the downstream riverbed and banks from erosion. Furthermore, the spillway's location atop the dam body saves land area on both banks, reduces excavation and backfilling work, thereby improving economic efficiency and saving investment. Simultaneously, this symmetrical spillway also beautifies the ecological environment and facilitates the creation of a waterfront landscape. Attached Figure Description

[0010] Figure 1 This is a 3D diagram of the spillway;

[0011] Figure 2 This is a partial top view of the spillway;

[0012] Structure numbering: 1-Overflow weir; 2-Spillway; 201-Inclined side channel; 202-Horizontal adjustment section; 203-Inclined spillway; 3-Swirl energy dissipation channel; 301-Straight section of water inlet; 302-Curved section of water outlet; 4-Primary stilling basin; 5-Stepped spillway; 6-Energy dissipation step; 7-Dam body; 8-Secondary stilling basin; 9-Tailgating channel; 10-Inner wall of spillway; 11-Outer wall of spillway. Detailed Implementation

[0013] The technical solutions of the present utility model will be clearly and completely described below with reference to the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0014] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "downstream side", "downstream dam surface", "middle and upper part", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the structure or part referred to must have a specific orientation, or be arranged and composed in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0015] like Figure 1 As shown, a symmetrical two-stage energy dissipation spillway includes an overflow weir 1, a spillway 2, a primary stilling basin 4, and a stepped spillway 5. The primary stilling basin 4 has spillways 2 symmetrically arranged at both ends. A stepped spillway 5 is provided on the downstream outlet dam face of the primary stilling basin 4. Multiple swirling energy dissipation channels 3 are symmetrically arranged along the water flow direction on the water-facing sidewalls of the spillway 2 on the inner sidewall 10 and outer sidewall 11. The spillway also includes a dam body 7, as shown in the diagram. Figure 1 As shown, its side cross-section is approximately trapezoidal, and the downstream face of dam body 7 (i.e. Figure 1The top of the inclined surface is provided with a spillway 2 and a primary stilling basin 4. The dam body 7 is inclined downward on the downstream dam surface and is provided with a stepped spillway 5. At the end of the stepped spillway 5, a secondary stilling basin 8 is provided horizontally. The secondary stilling basin 8 is connected to the tailrace channel 9. The tailrace channel 9 and the stepped spillway 5 can be set on the two sides adjacent to the secondary stilling basin 8, or on the opposite sides of the upstream and downstream (i.e., arranged in a straight line), depending on the topography and geological conditions of the downstream riverbed. The reservoir water flows into the symmetrical spillway 2 through the overflow weirs 1 at both ends. When the water flows through the swirling energy dissipation channels 3 on the water-facing side walls 10 and 11 of the inner and outer side walls of the spillway 2, some of the kinetic energy is eliminated. Then, the water continues to flow into the primary stilling basin 4 along the symmetrical spillway 2. The two streams of water collide violently in the primary stilling basin 4, dissipating energy. The water flows into the stepped spillway 5 on the downstream dam face through the downstream outlet of the primary stilling basin 4. The water is constrained and countered by the energy dissipation steps 6 arranged on the bottom plate of the stepped spillway 5, thus consuming a large amount of energy. Finally, the water falls into the secondary stilling basin 8 set at the end of the stepped spillway 5. In the secondary stilling basin 8, the water dissipates most of the kinetic energy through bottom flow energy dissipation (the water generates vortexes, collisions, turbulence, aeration, friction, shearing, etc.). The water with a slow flow velocity no longer has the harmful scouring effect and finally flows into the tailrace channel 9 and is diverted to the downstream river channel. The direction of the bold black arrow in the image represents the direction of the water flow.

[0016] like Figure 2 As shown, the spillway 2 along the water flow direction includes an inclined side channel 201, a horizontal adjustment section 202, and an inclined discharge channel 203 connected in sequence. The spillway 2 is connected to the toe of the overflow weir 1 in front and to the primary stilling basin 4 in the rear. The outer wall 11 within the area of ​​the inclined side channel 201 turns 90° in an arc on the horizontal plane. The water flowing in from the overflow weir 1 turns 90° horizontally through the side channel 201, and then the horizontal adjustment section 202 adjusts the water flow to a near-straight line before finally flowing into the primary stilling basin 4 through the inclined discharge channel 203.

[0017] like Figure 1 , Figure 2 As shown, swirling energy dissipation channels 3 are provided on the water-facing sidewalls of the inner sidewall 10 and outer sidewall 11 of the inclined spillway 203. The number of swirling energy dissipation channels 3 is selected according to the length, flow rate and velocity of the spillway 2. Only one set (two) of symmetrical channels is shown in the figure for illustration, which does not mean that there is only one set of swirling energy dissipation channels 3. Swirling energy dissipation channels 3 are not provided on the inner and outer sidewalls of the inclined side channel 201 and the horizontal adjustment section 202.

[0018] like Figure 2As shown, the swirling energy dissipation channel 3 includes a straight section 301 for the water inlet and an arc section 302 for the water outlet. The water flows into the swirling energy dissipation channel 3 through the straight section 301 and flows out through the arc section 302. The width of the swirling energy dissipation channel 3 gradually decreases from the water inlet to the water outlet to prevent cavitation damage. The tributary flowing out from the arc section 302 is nearly perpendicular to the main stream in the inclined spillway 203. The two water streams collide laterally to dissipate energy.

[0019] Working principle: The high-speed water flow from the symmetrically arranged overflow weir 1 flows into the symmetrically arranged inclined side channel 201. After the water flow turns 90° horizontally in the inclined side channel 201, it flows into the horizontal adjustment section 202. After the flow state and direction of the water flow are adjusted in the horizontal adjustment section 202, it continues to flow into the inclined spillway 203. Multiple swirling energy dissipation channels 3 are symmetrically arranged on the water-facing side walls of the inner side wall 10 and outer side wall 11 of the inclined spillway 203. The tributaries in the swirling energy dissipation channels 3 collide with the original main flow in the inclined spillway 203 at their outlets for the first energy dissipation. After the tributaries in the swirling energy dissipation channels 3 collide with and merge with the main flow in the inclined spillway 203, they continue to flow into the primary stilling pool 4. The symmetrically arranged high-speed water flow will undergo a violent collision after entering the primary stilling pool 4 for the second energy dissipation. After most of the kinetic energy is dissipated in the primary stilling basin 4, the water continues to flow into the stepped spillway 5 set on the downstream dam surface through the downstream outlet of the primary stilling basin 4. The water flow is constrained and counteracted by the energy dissipation steps 6 arranged on the bottom plate of the stepped spillway 5 to achieve the third energy dissipation. Finally, the water flow falls into the secondary stilling basin 8 and undergoes the fourth energy dissipation through the bottom flow energy dissipation method (the water flow generates vortex, collision, turbulence, aeration, friction, shearing and other effects). The water flow with a slow velocity and no longer has the harmful scouring effect finally flows into the tailrace channel 9 and is diverted to the downstream river channel.

[0020] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Any modifications, alterations, alterations, or substitutions made by those skilled in the art to the technical solutions of the present utility model without departing from the spirit of the present utility model shall fall within the protection scope defined by the claims of the present utility model.

Claims

1. A symmetrical two-stage energy dissipating spillway characterized in that: It includes overflow weir (1), spillway (2), first-stage stilling basin (4) and stepped spillway (5); the first-stage stilling basin (4) is symmetrically provided with the spillway (2) at both ends, the downstream side of the first-stage stilling basin (4) is provided with the stepped spillway (5), and the overflow weir (1) is connected with the input end of the spillway (2).

2. A symmetrical two-stage energy dissipating spillway according to claim 1, characterized in that: It also includes dam body (7), the top of the dam body (7) is provided with the spillway (2) and the first-stage stilling basin (4); the inner side wall (10) and the outer side wall (11) are provided on both sides of the spillway (2) along the length direction, a plurality of spiral energy dissipation grooves (3) are provided on the side close to the spillway (2) of the inner side wall (10) and the outer side wall (11) along the length direction; the dam body (7) is provided with the stepped spillway (5) at the downstream dam surface, the end of the stepped spillway (5) is provided with a second-stage stilling basin (8), and the second-stage stilling basin (8) is connected with tailrace (9).

3. A symmetrical two-stage dissipative spillway according to claim 2, characterized in that: The spiral energy dissipation groove (3) includes water flow inlet straight line segment (301) and water flow outlet arc line segment (302).

4. The symmetrical two-stage energy dissipating spillway according to claim 1, wherein: The stepped spillway (5) is provided with stepped energy dissipation steps (6) along the length direction.

5. The symmetrical two-stage dissipative spillway according to claim 1, wherein: The spillway (2) includes inclined side groove (201), horizontal adjustment section (202) and inclined spillway (203), and the inclined side groove (201), the horizontal adjustment section (202) and the inclined spillway (203) are sequentially connected.

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