Aerated stepped energy dissipater

Abstract

The utility model relates to a kind of ventilated ladder energy dissipation hydraulic tunnel, it is related to the field of hydraulic tunnel energy dissipation facilities, including base, multiple stages of energy dissipation steps are arranged on base, and each stage of energy dissipation step includes first step surface and the first right angle surface vertically connected with first step surface;First step surface is provided with energy dissipation weir with trapezoidal cross section, the water face of energy dissipation weir is vertical plane, vertical plane and first step surface vertically form first energy dissipation right angle, the backwater surface of energy dissipation weir is inclined plane, and inclined plane forms first energy dissipation concave angle with first step surface;Energy dissipation step both sides are symmetrically provided with flow guide wall, and vertical arrangement is provided with air hose in each stage of energy dissipation step both sides flow guide wall, and the lower air hole of air hose is opened in the side surface of flow guide wall below first step surface, and the upper air hole of air hose is opened in the top of flow guide wall near vault top place.The utility model effectively solves the problem of low energy dissipation efficiency, cavitation phenomenon and silt scouring of traditional structure, and significantly improves stability and durability.

Description

Technical Field

[0001] This utility model relates to the field of energy dissipation facilities for hydraulic tunnels, specifically to a ventilated stepped energy dissipation hydraulic tunnel. Background Technology

[0002] In hydraulic tunnels such as spillways and water conveyance tunnels, the flow velocity increases significantly when the longitudinal slope is large. High-speed water flow, passing through tunnels and maintenance shafts, causes severe erosion and wear on the inner walls. This is especially true when the water carries large particles of sediment, which easily accumulate permanently on energy dissipation structures (such as traditional steps and stilling basins). Under continuous water flow impact, this accumulated sediment repeatedly collides with the structure's surface, further exacerbating structural damage. This not only reduces energy dissipation efficiency but also shortens the tunnel's service life and significantly increases the maintenance costs throughout the project's lifecycle.

[0003] Currently, while common energy dissipation measures in engineering practice can partially mitigate the impact of water flow, they still have the following problems: First, insufficient energy dissipation efficiency: Although the right-angled structure of traditional steps can create a hydraulic jump, its energy dissipation for high-speed water flow is limited. Furthermore, with the continuous accumulation of silt, the hydraulic characteristics of the energy dissipation structure will change, leading to irreversible attenuation of the energy dissipation effect. Second, high risk of cavitation damage: The negative pressure area formed by the falling water flow will accumulate a large amount of air. When the water flow pressure changes, this accumulated air will trigger cavitation, causing continuous damage to the step structure. At the same time, under long-term erosion by silt, the structural integrity and stability of the energy dissipation structure will continuously decline, making it difficult to meet the long-term safe operation requirements of the project. Utility Model Content

[0004] The purpose of this invention is to provide a ventilated stepped energy dissipation hydraulic tunnel that effectively solves the problems of low energy dissipation efficiency, cavitation, and silt erosion in traditional structures, and significantly improves stability and durability.

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: a ventilated stepped energy dissipation hydraulic tunnel, including an inclined base. Multiple energy dissipation steps are arranged sequentially on the inclined surface of the base according to the water flow direction. Each energy dissipation step includes a first step surface and a first right-angled surface perpendicularly connected to the first step surface. An energy dissipation sill with a trapezoidal cross-section is provided on the first step surface. The water-facing surface of the energy dissipation sill is a vertical plane, which forms a first energy dissipation right angle with the first step surface. The water-repellent surface of the energy dissipation sill is an inclined surface, which forms a first energy dissipation concave angle with the first step surface. Guide walls are symmetrically arranged on both sides of the energy dissipation steps. Vertically arranged ventilating hoses are provided within the guide walls on both sides of each energy dissipation step. The lower vent of the ventilating hose is located on the side of the guide wall below the first step surface, and the upper vent is located at the top of the guide wall near the arch. The ventilating hose is used to discharge the air accumulated below the steps to the top of the tunnel through the pressure difference generated by the water flow, preventing cavitation.

[0006] As a preferred embodiment, a maintenance step is provided in the middle of the first right-angled surface. The maintenance step includes two consecutive steps, and the width of the maintenance step is smaller than the width of the first step surface.

[0007] As a preferred embodiment, each maintenance step includes a second step surface and a second right-angled surface perpendicularly connected to the second step surface. Adjacent second step surfaces and second right-angled surfaces are connected to form a second transition right angle, and a second scouring right angle is formed between two adjacent maintenance steps.

[0008] As a preferred embodiment, the first step surface of the energy dissipation step is inclined downward along the water flow direction to form a slope for guiding the water flow, and the first right-angled surface and the first step surface of the next energy dissipation step are connected to form a first scouring right angle.

[0009] As a preferred embodiment, the inner side of the guide wall is coplanar with the side of the energy dissipation step, and an energy dissipation water flow channel of equal width is formed between the two guide walls.

[0010] As a preferred embodiment, the orifice directions of the lower vent and the upper vent are perpendicular to the water flow direction.

[0011] As a preferred embodiment, the opening height of the upper vent of the guide wall is higher than the highest operating water level line of the energy dissipation step design.

[0012] Based on the above technical solution, the beneficial effects of this utility model are: 1. This application incorporates trapezoidal energy dissipation sills on multi-stage energy dissipation steps. Through their unique geometric structure, these sills alter the flow pattern, causing strong vortices, air mixing, and energy dissipation as the water flows through, thereby significantly reducing the kinetic energy of the water. Compared to traditional energy dissipation structures, this design not only improves energy dissipation efficiency but also optimizes flow stability, effectively suppressing downstream turbulence and reducing the risk of scour.

[0013] 2. This application addresses the cavitation problem caused by hydraulic jump below the steps by innovatively installing a ventilation hose system inside the guide wall to release gas in the negative pressure zone in a timely manner, reducing the damage of cavitation to the step structure, effectively improving the water flow pattern, enhancing the energy dissipation effect, reducing structural vibration and noise, adapting to high flow or high drop conditions, and being easy to maintain, significantly improving the durability of the structure.

[0014] 3. This application arranges multiple energy dissipation steps in sequence according to the water flow direction in the hydraulic tunnel. The step-by-step energy dissipation effectively disperses the impact force of high-speed water flow, greatly reduces the scouring and wear of silt particles on the tunnel wall and maintenance well, significantly extends the service life of the tunnel, reduces the maintenance frequency and cost, and provides a reliable guarantee for the long-term stable operation of the project.

[0015] 4. This application sets up maintenance steps in the multi-level energy dissipation steps, providing a safe and convenient passage for operation and maintenance personnel, significantly improving maintenance efficiency, and while ensuring operation and maintenance safety, it can also perform secondary energy dissipation on the water flow. Attached Figure Description

[0016] Figure 1 This is a cross-sectional schematic diagram of the present invention; Figure 2 This is a cross-sectional schematic diagram from another perspective of the present invention; Figure 3 This is a structural schematic diagram of the multi-stage energy dissipation steps, base, maintenance steps, and energy dissipation sill in this utility model; Figure 4 for Figure 3 Enlarged view of point A in the middle; Figure 5 for Figure 3 A structural diagram from another perspective; Figure 6 for Figure 5 Enlarged view at point B in the middle; Figure 7 for Figure 5 Enlarged view at point C; Figure descriptions: 1. Energy dissipation step, 11. First step surface, 12. First right angle surface, 13. First scour right angle, 2. Base, 3. Maintenance step, 31. Second step surface, 32. Second right angle surface, 33. Second scour right angle, 34. Second transition right angle, 4. Guide wall, 5. Energy dissipation sill, 51. First energy dissipation right angle, 52. First energy dissipation concave angle, 6. Ventilation hose, 61. Lower vent, 62. Upper vent. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0018] The structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0019] Furthermore, it should be noted that, unless otherwise stated, "several" means two or more; the terms "upper," "lower," "left," "right," "front end," "rear end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of implementation of this utility model. In addition, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] like Figure 1 As shown, a ventilated stepped energy dissipation hydraulic tunnel includes an inclined platform 2. Multiple energy dissipation steps 1 are arranged sequentially on the inclined surface of the platform 2 according to the water flow direction. Each energy dissipation step 1 includes a first step surface 11 and a first right-angled surface 12 perpendicularly connected to the first step surface 11. The first step surface 11 of the energy dissipation step 1 is inclined downward along the water flow direction to form a slope for guiding the water flow. The first right-angled surface 12 and the first step surface 11 of the next energy dissipation step 1 are connected to form a first scour right angle 13.

[0021] In this embodiment, the dimensions of the energy dissipation step 1 are as follows: step width 3m, length along the water flow direction 12m, and vertical height 0.56m.

[0022] An energy dissipation sill 5 with a trapezoidal cross-section is provided on the first step surface 11. The water-facing side of the energy dissipation sill 5 is a vertical plane, which is perpendicular to the first step surface 11 to form a first energy dissipation right angle 51. The water-repelling side of the energy dissipation sill 5 is an inclined plane, which forms a concave angle greater than the first energy dissipation angle 52 with the first step surface 11. In this embodiment, the vertical height of the energy dissipation sill 5 provided on the step surface is 0.3m.

[0023] The energy dissipation step 1 is symmetrically provided with guide walls 4 on both sides. The inner side of the guide wall 4 is coplanar with the side of the energy dissipation step 1, and an energy dissipation water flow channel of equal width is formed between the two guide walls 4.

[0024] Each energy dissipation step 1 has vertically arranged ventilation hoses 6 installed within the guide walls 4 on both sides. The lower ventilation port 61 of each ventilation hose 6 is located on the side of the guide wall 4 below the first step surface 11, and the upper ventilation port 62 is located at the top of the guide wall 4 near the arch. The ventilation hoses 6 are used to discharge air accumulated below the step to the top of the tunnel through the pressure difference generated by the water flow, preventing cavitation. The openings of the lower ventilation port 61 and the upper ventilation port 62 are perpendicular to the water flow direction; the opening height of the upper ventilation port 62 on the guide wall 4 is higher than the designed maximum operating water level of the energy dissipation step 1.

[0025] In this embodiment, the diameter of both the lower vent 61 and the upper vent 62 is designed to be 100mm.

[0026] A maintenance step 3 is provided in the middle of the first right-angled surface 12. The maintenance step 3 includes two consecutive steps, and the width of the maintenance step 3 is smaller than the width of the first step surface 11. Each maintenance step 3 includes a second step surface 31 and a second right-angled surface 32 perpendicularly connected to the second step surface 31. Adjacent second step surfaces 31 and second right-angled surfaces 32 are connected to form a second transition right angle 34, and a second scouring right angle 33 is formed between adjacent maintenance steps 3.

[0027] How this application works: This energy dissipation system achieves efficient dissipation of high-speed water flow energy through multi-stage stepped energy dissipation, eddy current enhancement, and dynamic exhaust. When the high-speed water flow enters the tunnel, it first flows through the energy dissipation step 1. The 90° first scour right angle 13 formed by the first step surface 11 and the first right angle surface 12 forces the water flow to generate violent turbulence, shear friction, and hydraulic jump phenomena. Through the stepped drop layout of the multi-stage energy dissipation step 1, the kinetic energy of the water flow is dissipated step by step, and the flow velocity gradually decreases.

[0028] The water-facing surface of the trapezoidal energy dissipation sill 5 directly impacts the water flow through the first energy dissipation right angle 51, while the first energy dissipation concave angle 52, which is larger than the back water surface, guides the water flow to form a three-dimensional vortex, which greatly improves the water-air mixing rate and enhances the energy dissipation efficiency.

[0029] The maintenance step 3, through the second scouring right angle 33 and the second transition right angle 34 formed by the second step surface 31 and the second right angle surface 32, performs secondary energy dissipation on the central water flow in the middle of the energy dissipation step 1, reducing the scouring pressure on the side structures, and at the same time providing a safe passage for maintenance personnel. Its width is designed to be smaller than the first step surface 11 to ensure that the energy dissipation effect is not affected.

[0030] As the water flows down, a negative pressure zone is created below the step. The accumulated air is automatically discharged through the ventilation hose 6 inside the guide wall 4. The lower vent 61, located in the negative pressure zone, and the upper vent 62, which is above the highest water level, use the pressure difference to guide the air to the tunnel arch, completely eliminating the risk of cavitation. The inner side of the guide wall 4 is coplanar with the side of the energy dissipation step 1, forming a water flow channel of equal width to ensure flow stability.

[0031] The coordinated operation of these functional components enables the system to achieve efficient energy dissipation while maintaining structural stability and ease of maintenance, forming a complete energy dissipation system of "stepped energy dissipation-eddy current enhancement-pressure balance", which is particularly suitable for hydraulic tunnel projects under high flow velocity conditions.

[0032] It should be noted that the above embodiments are only used to illustrate the present utility model, but the present utility model is not limited to the above embodiments. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A ventilated stepped energy dissipation hydraulic tunnel, characterized in that: The base (2) is inclined and has multiple energy dissipation steps (1) arranged in sequence on the inclined surface of the base (2) in the direction of water flow. Each energy dissipation step (1) includes a first step surface (11) and a first right-angled surface (12) that is perpendicular to the first step surface (11). An energy dissipation sill (5) with a trapezoidal cross-section is provided on the first step surface (11). The water-facing surface of the energy dissipation sill (5) is a vertical plane, which is perpendicular to the first step surface (11) to form a first energy dissipation right angle (51). The water-repelling surface of the energy dissipation sill (5) is an inclined plane, which forms a first energy dissipation concave angle (52) with the first step surface (11). The energy dissipation step (1) is symmetrically provided with guide walls (4) on both sides. Each energy dissipation step (1) is provided with vertically arranged ventilation hoses (6) in the guide walls (4) on both sides. The lower ventilation hole (61) of the ventilation hose (6) is opened on the side of the guide wall (4) below the first step surface (11), and the upper ventilation hole (62) of the ventilation hose (6) is opened at the top of the guide wall (4) near the arch. The ventilation hose (6) is used to discharge the air accumulated below the step to the top of the tunnel through the pressure difference generated by the water flow to prevent cavitation.

2. A ventilated stepped energy dissipation hydraulic tunnel according to claim 1, characterized in that: A maintenance step (3) is provided in the middle of the first right-angled surface (12). The maintenance step (3) includes two consecutive steps, and the width of the maintenance step (3) is smaller than the width of the first step surface (11).

3. A ventilated stepped energy dissipation hydraulic tunnel according to claim 2, characterized in that: Each maintenance step (3) includes a second step surface (31) and a second right angle surface (32) that is perpendicular to the second step surface (31). Adjacent second step surfaces (31) and second right angle surfaces (32) are connected to form a second transition right angle (34), and a second scouring right angle (33) is formed between two adjacent maintenance steps (3).

4. A ventilated stepped energy dissipation hydraulic tunnel according to claim 1, characterized in that: The first step surface (11) of the energy dissipation step (1) is inclined downward along the water flow direction to form a slope for guiding the water flow. The first right angle surface (12) and the first step surface (11) of the next energy dissipation step (1) are connected to form a first scouring right angle (13).

5. A ventilated stepped energy dissipation hydraulic tunnel according to claim 1, characterized in that: The inner side of the guide wall (4) is coplanar with the side of the energy dissipation step (1), and an energy dissipation water flow channel of equal width is formed between the two guide walls (4).

6. A ventilated stepped energy dissipation hydraulic tunnel according to claim 1, characterized in that: The openings of the lower vent (61) and upper vent (62) are perpendicular to the direction of water flow.

7. A ventilated stepped energy dissipation hydraulic tunnel according to claim 6, characterized in that: The opening height of the upper vent (62) of the guide wall (4) is higher than the highest operating water level line designed for the energy dissipation step (1).

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