A ski-jump bucket

Abstract

The present invention provides a ski-jump bucket which is connected to a spillway. The bottom plate of the outlet section of the spillway is connected to an inclined bottom slope that descends along the way. The width of the inclined bottom slope increases along the way in the downstream direction to form a plunge bucket, and the plunge bucket is flush with the end of the side wall of the spillway. The outlet of the plunge bucket is immediately followed by a group of dentated sills. The group of dentated sills includes N dentated sills arranged at intervals, dividing the outlet of the plunge bucket into N + 1 plunge flow areas and N ski-jump areas. By arranging a group of dentated sills composed of a plurality of dentated sills arranged at intervals at the outlet of the plunge bucket with a width increasing along the way in the downstream direction at the end of the spillway, the ski-jump bucket enables the water flow that has been laterally diffused along the way in the chute to form a three-dimensional water tongue in space, reduces the unit discharge at the outlet of the spillway, has a low downstream scour depth and hydraulic index, and reduces the protection project quantity and construction cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of flip energy dissipation in hydraulic engineering, and particularly relates to a flip bucket. Background Art

[0002] Flip energy dissipation means that different forms of flip buckets are arranged at the end of a water discharge structure to project the high-speed water flow discharged from the upstream downstream, and part of the energy is dissipated through the diffusion, turbulence and aeration of the jet in the air, and then it falls into the river channel far from the building and dissipates energy in a water cushion with a certain depth and range. Since flip energy dissipation has the advantages of simple structure, economy, convenient maintenance, etc., when the downstream geological conditions are good and the requirements for waves are not high, flip energy dissipation is mostly used in water conservancy and hydropower projects.

[0003] Among various types of commonly used flip buckets at present, the conventional continuous flip bucket has a large unit discharge per unit width of water entry, deep downstream scouring and high hydraulic indexes; on the basis of the conventional continuous flip bucket, the differential flip bucket adds convex bodies at intervals, which can effectively disperse the water entry width of the water jet discharged from a single chute, reduce the unit discharge per unit width of water entry and mitigate the downstream scouring depth. However, when convex bodies are arranged on the continuous flip bucket, the risk of cavitation and erosion on both sides of the convex bodies is large; the narrow slot flip bucket makes the discharged water flow longitudinally stretched, which can reduce the scouring effect of flood discharge on the slope, but the downstream scouring is generally deep; the bevel cut flip bucket can effectively disperse the water flow leaving the bucket and reduce the unit discharge per unit width of water entry, and is mainly applicable to bank spillways; the tongue-shaped flip bucket can disperse the water flow leaving the bucket transversely and reduce the unit discharge per unit width of water entry, and is mainly applicable to a relatively wide downstream river channel. After the facility discharges water, there is a lot of water accumulation in the reverse arc section of the flip bucket, which is not conducive to maintenance. At the same time, the above-mentioned various types of flip buckets all have varying degrees of atomization problems, which are not conducive to the slope stability and facility protection around the flood discharge and energy dissipation area. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a flip bucket with a simple structure, which has the advantages of small unit discharge per unit width of water entry, low risk of cavitation and erosion, shallow downstream river channel scouring and small atomization.

[0005] A flip bucket disclosed by the present invention is connected to a spillway. The bottom plate of the outlet section of the spillway is connected to an inclined bottom slope that descends along the way, and the width of the inclined bottom slope increases along the way in the downstream direction to form a downward shooting flip bucket, and the downward shooting flip bucket is flush with the end of the side wall of the spillway;

[0006] The outlet of the downward shooting flip bucket is immediately followed by a group of toothed dams. The group of toothed dams includes N toothed dams arranged at intervals, and divides the outlet of the downward shooting flip bucket into N + 1 downward shooting flow areas and N flip flow areas;

[0007] The structural parameters of any one of the toothed dams include the starting end width, length and flip angle, where:

[0008] The starting end width of any one of the said tooth sills is selected from B2 and B4. The value range of B2 is [0.6h, h], and the value range of B4 is [0.8h, 1.5h], where h is the water depth at the end of the spillway's downward-firing bucket under the maximum discharge condition.

[0009] The length of any one of the said tooth sills is selected from L1 and L2. , , where: q is the discharge per unit width at the end of the spillway's downward-firing bucket (3) under the maximum discharge condition.

[0010] The pick angle of any one of the said tooth sills is selected from θ1 and θ2. , , where: The value range of is [4°, 8°], and v is the flow velocity at the end of the spillway's downward-firing bucket (3) under the maximum discharge condition.

[0011] The end of the spillway is set as a downward-firing bucket. The width of the bucket section increases along the downstream direction, causing the water flow to diffuselaterally along the chute, reducing the discharge per unit width at the spillway outlet. A tooth sill group composed of multiple tooth sills arranged at intervals is set at the outlet of the downward-firing bucket, dividing the bucket outlet into multiple downward-firing flow areas and multiple flip-flow areas, enabling the water flow after leaving the bucket to form a spatially multi-dimensional water tongue with full lateral and longitudinal diffusion, further reducing the discharge per unit width at the spillway outlet. At the same time, the structural parameters of each tooth sill can be differentially set to form downward-firing flow areas and flip-flow areas with different sizes, different discharges per unit width, and controllable landing positions, matching different downstream boundary conditions.

[0012] Furthermore, a side aeration sill is provided on the inner wall of the side wall where the downward-firing bucket is connected to the spillway. The side aeration sill is of the sudden-expansion type, and the sudden-expansion width b1 has a value range of [0.20 m, 0.40 m].

[0013] Setting a sudden-expansion type side aeration sill on the inner wall of the side wall at the starting section of the downward-firing bucket can avoid cavitation damage caused by the high-speed water flow affecting the diffusive side wall.

[0014] Furthermore, the pick angle θ of the downward-firing bucket has a value range of [-10°, -30°], making the water tongue pick distance short and suppressing the atomization caused by flood discharge.

[0015] Furthermore, the difference Δh between the end elevation of the downward-firing bucket and the downstream highest water level is less than 10 m, enabling the water flow in the downward-firing flow area after leaving the bucket to directly enter the downstream river channel and collide and shear with the water body to dissipate energy.

[0016] Furthermore, the diffusion angle α1 of the left side wall of the downward-firing bucket has a value range of [1°, 7°].

[0017] Furthermore, the diffusion angle α2 of the right wall of the downward-facing overhanging ridge has a value range of [1°, 7°].

[0018] According to the determined landing point position, the diffusion angles of the left and right walls of the prone sill are flexibly adjusted to adjust the diffusion direction of the sill, so as to ensure that the water falls at the designed landing point after flowing out of the sill to avoid impacting the downstream slope.

[0019] Furthermore, the contraction angle β of the tooth ridge has a value range of [0°, 10°]. The tooth ridge can be a rectangular tooth ridge of equal width or a trapezoidal tooth ridge that gradually contracts along the direction of the water flow according to different flow selection area parameters.

[0020] Furthermore, the teeth in the tooth group are arranged in an alternating pattern with regular sizes; the protruding teeth ensure smooth air supply on both sides of the teeth to avoid cavitation. At the same time, the separated adjacent diversion areas allow the water flow to diffuse and stretch in the air before entering the downstream, significantly improving the energy dissipation efficiency; or, the teeth in the tooth group are arranged in a pattern with a number of large teeth in the middle and a number of small teeth symmetrically arranged on both sides; the middle large tooth stretches the water tongue range longitudinally, concentrates the mainstream to the distant deep water area, and fully utilizes the water cushion to dissipate braking energy; the middle large tooth guides the water flow to fall away from the structural foundation, reducing the impact on the proximal riverbed; the small teeth on both sides assist in dispersing the water flow, promote the full longitudinal and lateral diffusion of the water tongue, improve the overall energy dissipation effect, weaken the concentrated scouring force of the opposite slope, and reduce the depth of the scouring pit.

[0021] Furthermore, the height difference △Z between the tooth sill group and the bottom plate of the downstream river channel is greater than 20.0m, and the height difference is increased to extend the range, making it easier to dissipate energy in deep water areas.

[0022] The present invention has the following beneficial effects:

[0023] 1) The nose sill provided by the present invention adopts a diffusion-type plunging sill design at the end of the spillway, so that the water tongue in the chute can diffuse significantly in the lateral direction. A plurality of tooth sills arranged at intervals are arranged after the plunging diffusion sill, so that the water tongue can fully diffuse in the longitudinal and lateral directions after leaving the sill, forming a multi-dimensional space water tongue. The single-width flow is greatly reduced compared with the traditional continuous sill, the downstream scouring depth and hydraulic index are low, and the amount of protective engineering and construction costs are reduced;

[0024] 2) The nose sill provided by the present invention is provided with multiple tooth sills for adjusting the water tongue landing point on the downstream side of the downward-facing sill, which has a simple structure, smooth water flow transition, no cavitation risk, and no operation restrictions;

[0025] 3) The water tongue of the nose ridge provided by the present invention has a short flying distance, and the water tongue has small air expansion in the air, which avoids the strong atomization caused by the high-speed water flow entering the downstream, and ensures the stability of the downstream slope and the safe operation of nearby buildings, roads and equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the plan layout of the flip bucket nose structure provided by some embodiments of the present invention.

[0027] Figure 2 It is a schematic diagram of the plane structure parameters of the flip bucket nose provided by some embodiments of the present invention.

[0028] Figure 3 It is a schematic diagram of the cross-sectional structure of the flip bucket nose provided by some embodiments of the present invention.

[0029] Figure 4 It is a schematic diagram of the corresponding tooth profile of the flip bucket nose 6-1 flip flow area provided by an embodiment of the present invention.

[0030] Figure 5 It is a schematic diagram of the corresponding tooth profile of the flip bucket nose 6-2 flip flow area provided by an embodiment of the present invention.

[0031] Figure 6 It is a schematic diagram of the corresponding tooth profile of the flip bucket nose 6-3 flip flow area provided by an embodiment of the present invention.

[0032] Explanation of reference numerals:

[0033] 1 Outlet section of the spillway, 2 Side walls of the spillway, 3 Divergent bucket, 4 Side aeration weir, 5-1 Divergent flow area, 5-2 Divergent flow area, 5-3 Divergent flow area, 5-4 Divergent flow area, 6-1 Flip flow area, 6-2 Flip flow area, 6-3 Flip flow area, 7 Apron, 8 Downstream river channel, 9 Area where the flip water jet falls;

[0034] Parameter identification:

[0035] Width b of the spillway in front of the bucket, height b1 of the side aeration weir, diffusion angle α1 of the left side wall of the divergent bucket, diffusion angle α2 of the right side wall of the divergent bucket, height H of the side wall of the divergent bucket, flip angle θ of the divergent bucket, outlet width B of the divergent bucket,

[0036] Outlet width B1 of the divergent flow area 5-1, outlet width B3 of the divergent flow area 5-2, outlet width B5 of the divergent flow area 5-3, outlet width B7 of the divergent flow area 5-4;

[0037] Starting end width B2 and length L1 of the corresponding tooth of the flip flow area 6-1; flip angle θ1, contraction angle β1, arc radius R1,

[0038] Starting end width B4 and length L2 of the corresponding tooth of the flip flow area 6-2; flip angle θ2, contraction angle β2, arc radius R2,

[0039] Starting end width B6 and length L3 of the corresponding tooth of the flip flow area 6-3; flip angle θ3, contraction angle β3, arc radius R3;

[0040] The difference Δh between the elevation of the end of the downward - shooting bucket and the highest downstream water level, the difference ΔZ between the elevation of the end of the negative - shooting bucket and the bottom elevation of the downstream river channel, and the length L of the apron. Specific implementation manners

[0041] To describe the technical solution of the present invention more clearly and completely, the following further details the present invention through specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, and various changes can be made within the scope defined by the rights of the present invention.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific implementation manners and are not intended to limit the present invention. The term “and / or” used herein includes any and all combinations of one or more of the related listed items.

[0043] The present invention provides a flip - bucket nose, which is connected to a spillway. The bottom plate of the outlet section 1 of the spillway is connected to a sloping bottom slope that descends along the way. The width of the sloping bottom slope increases along the way in the downstream direction to form a downward - shooting bucket 3, so that the water flow laterally diffuses along the way in the chute, reducing the unit discharge at the spillway outlet. The flip angle θ of the downward - shooting bucket 3 ranges from [−10°, −30°], and the downward - shooting bucket 3 is flush with the end of the side wall 2 of the spillway; the diffusion angles of the left and right side walls of the downward - shooting bucket 3 are α1 and α2 respectively, and the value range is [1°, 7°]. To avoid cavitation damage to the diffusion side wall caused by high - speed water flow, a side - aeration weir 4 is provided on the inner wall of the side wall at the starting end where the downward - shooting bucket 3 is connected to the spillway. The side - aeration weir 4 is in the form of sudden expansion, and the sudden - expansion width b1 ranges from [0.20 m, 0.40 m].

[0044] The outlet of the downward - shooting bucket 3 is immediately followed by a set of toothing. The outlet width of the downward - shooting bucket 3 is B. The set of toothing includes N toothings arranged at intervals, dividing the outlet of the downward - shooting bucket 3 into N + 1 downward - shooting flow regions and N flip - flow regions. In an implementation manner provided by the present invention, as Figure 1 and Figure 2 shown, the set of toothing includes three toothings. The middle toothing is an isosceles trapezoid with a slightly larger shape, and two isosceles trapezoids with slightly smaller shapes are symmetrically distributed on both sides. The three toothings divide the outlet of the downward - shooting bucket into four downward - shooting flow regions 5 - 1, 5 - 2, 5 - 3 and 5 - 4 and three flip - flow regions 6 - 1, 6 - 2 and 6 - 3.

[0045] The widths of the four downward jet regions 5-1, 5-2, 5-3, and 5-4 are B1, B3, B5, and B7 respectively. Among them, B1 = B7, and the value ranges of B1 and B7 are [0.4h, 0.8h]; B3 = B5, and the value ranges of B3 and B5 are [0.6h, h]; h is the water depth at the end of the spillway downward jet bucket under the maximum discharge condition.

[0046] The water flow in the downward jet region falls on the proximal end of the bucket, making full use of the water body at the front end of the downstream energy dissipation region for energy dissipation, thus improving the energy dissipation effect. At the same time, due to the downward jet type, the lateral diffusion of the water flow in the B1 and B7 jet regions can be controlled, and the front and rear positions of the water tongue are fixed under various operating conditions, which is beneficial to the protection of the downstream bank slope.

[0047] The widths, lengths, and bucket angles of the tooth ridges forming the ski-jump regions 6-1, 6-2, and 6-3 can be the same, or can be set according to the differences in downstream boundary conditions; the value range of the contraction angle β of the tooth ridge is [0°, 10°]. The planes of the tooth ridges in the three ski-jump regions can be rectangular (β = 0°) or trapezoidal (the value range of β is (0°, 10°]) to achieve effective diffusion of the water tongues in the longitudinal and lateral directions in each ski-jump region, reduce the unit discharge at entry, and improve the energy dissipation rate and the stability of the downstream water surface.

[0048] The widths, lengths, and bucket angles of the tooth ridge corresponding to the ski-jump region 6-2 are larger than those of the tooth ridges corresponding to the ski-jump regions 6-1 and 6-3.

[0049] a) The structural parameters of the tooth ridge corresponding to the ski-jump region 6-1 are designed according to the following requirements:

[0050] The starting width B2 of the tooth ridge corresponding to the ski-jump region 6-1, and the value range of B2 is [0.6h, h], where h is the water depth at the end of the spillway downward jet bucket under the maximum discharge condition;

[0051] The length L1 of the tooth ridge corresponding to the ski-jump region 6-1:

[0052] ,

[0053] where: q is the unit discharge at the end of the spillway downward jet bucket under the maximum discharge condition;

[0054] The value range of the contraction angle β1 of the tooth ridge corresponding to the ski-jump region 6-1 is [5°, 10°];

[0055] The bucket angle θ1 of the tooth ridge corresponding to the ski-jump region 6-1 is increased on the basis of the downward angle θ of the downward jet bucket , and the value range of is [4°, 8°].

[0056] b) The structural parameters of the tooth ridge corresponding to the ski-jump region 6-2 are designed according to the following requirements:

[0057] The width B4 of the starting end of the dentate sill corresponding to the flip flow area 6-2, and the value range of B4 is [0.8h, 1.5h], where h is the water depth at the end of the spillway's downward shooting bucket under the condition of the maximum discharge;

[0058] The length L2 of the dentate sill corresponding to the flip flow area 6-2:

[0059] ,

[0060] In the formula: q is the unit discharge at the end of the spillway's downward shooting bucket under the condition of the maximum discharge;

[0061] The contraction angle β2 of the dentate sill corresponding to the flip flow area 6-2 has a value range of [5°, 10°];

[0062] The flip angle θ2 of the dentate sill corresponding to the flip flow area 6-2:

[0063] ,

[0064] In the formula: θ is the downward angle of the downward shooting bucket 3; q is the unit discharge at the end of the spillway's downward shooting bucket 3 under the condition of the maximum discharge; v is the flow velocity at the end of the spillway's downward shooting bucket 3 under the condition of the maximum discharge.

[0065] c) The structural parameters of the dentate sill corresponding to the flip flow area 6-3 refer to the design of the dentate sill corresponding to the flip flow area 6-1. The width B6 of the starting end of the dentate sill corresponding to the flip flow area 6-3 = B2, the length L3 = L1; the flip angle θ3 = θ1, the contraction angle β3 = β1, and the circular arc radius R3 = R1.

[0066] The drop ΔZ between the negative flip bucket of the flip bucket sill and the downstream riverbed 8 should be greater than 20.0 m to extend the shooting range and facilitate energy dissipation using the deep water area.

[0067] Embodiment

[0068] For a certain project to control the atomization effect and reduce the impact of flood discharge atomization on the downstream slope and facilities and equipment, a diffusive downward flip combined flip bucket sill is adopted at the end of the water discharge structure, and its specific structure is as Figures 1-6 shown. The maximum discharge of the project is 3200 m³ / s, and the maximum dam height is 158.00 m.

[0069] As Figure 1 , Figure 2 shown, the diffusive downward flip combined flip bucket sill of this embodiment is composed of a diffusive downward shooting bucket 3 with side walls at the outlet section of the spillway and three dentate sills arranged at the end of the diffusive downward shooting bucket 3. A side aeration sill 4 is arranged at the starting end of the diffusive side wall, and a concrete apron 7 is arranged to connect between the end of the water discharge structure and the downstream riverbed.

[0070] Structural parameters and dimensions: The width of the spillway upstream of the flip bucket is 14.00 m. Before entering the downward-firing flip bucket section, the side walls of the chute symmetrically diverge to both sides, and the divergence angles α1 and α2 are both 7°. The width B of the chute at the end of the downward-firing flip bucket section is 22.00 m; the angle of the downward-firing flip bucket section is -25°, the height of the side wall is 13.50 m, and the differences between the end of the downward-firing flip bucket and the downstream highest water level and the downstream riverbed bottom elevation are 4.00 m and 52.14 m respectively; three tooth bars are symmetrically arranged at the end of the downward-firing flip bucket, dividing the spillway outlet into four downward-firing areas 5-1, 5-2, 5-3 and 5-4 and three flip-flow areas 6-1, 6-2 and 6-3. The flow widths B1, B3, B5 and B7 of the four downward-firing areas 5-1, 5-2, 5-3 and 5-4 are 2.50 m, 3.00 m, 3.00 m and 2.50 m respectively, and the flow widths B2, B4 and B6 of the three flip-flow areas 6-1, 6-2 and 6-3 corresponding to the tooth bars are 3.00 m, 5.00 m and 3.00 m respectively; the lengths L1, tooth bar contraction angles β1, circular arc radii R1 and flip angles θ1 of the tooth bars are 5.30 m, 5°, 53.50 m and -18.878° respectively; the lengths L2, tooth bar contraction angles β2, circular arc radii R2 and flip angles θ2 of the tooth bars are 8.10 m, 5°, 52.00 m and -15.477° respectively; the parameters of the tooth bars corresponding to the flip-flow areas 6-1 and 6-3 are the same; a 50.00 m long concrete apron 7 is provided at the head of the connection between the end of the spillway and the downstream river channel 8.

[0071] The results of the overall hydraulic model test show that under the condition of the maximum discharge, the use of a diffusive downward-firing combined flip bucket at the spillway outlet makes the water level difference between the outlet and the downstream small, and the generated atomization is limited within the plunge pool, with little impact; after the flip bucket, the water jet fully diffuses, and the scour depth in the water jet falling area 9 is only 6.40 m, which is 9.30 m shallower than that when only using the downward-firing flip bucket, reducing the difficulty of energy dissipation and erosion prevention and saving the project investment.

[0072] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

Claims

1. A flip bucket, connected to a spillway, is characterized in that, The bottom plate of the outlet section (1) of the spillway is connected to a sloping bottom slope that descends along the way. The width of the sloping bottom slope increases along the downstream direction to form a plunge bucket (3), and the plunge bucket (3) is flush with the end of the side wall (2) of the spillway; The outlet of the plunge bucket (3) is immediately followed by a group of dentate sills. The group of dentate sills includes N dentate sills arranged at intervals, dividing the outlet of the plunge bucket (3) into N + 1 plunge flow areas and N flip flow areas, so that the water flow that has been laterally diffused along the chute forms a three-dimensional water tongue in space; The structural parameters of any one of the dentate sills include the starting end width, length, and flip angle, where: The starting end width of any one of the dentate sills is selected from one of B2 and B4. The value range of B2 is [0.6h, h], and the value range of B4 is [0.8h, 1.5h], where h is the water depth at the end of the plunge bucket of the spillway under the condition of the maximum discharge; Select one of the lengths L1 and L2 for any of the said toothing sills, L1 , L2 , where: q is the unit discharge at the end of the spillway plunge bucket (3) under the condition of the maximum discharge; Select one of the pick angles θ1 and θ2 for any of the said tooth ridges, where θ1 = θ + △θ, , where: θ is the pick angle of the downward-firing picket (3), the value range of △θ is [4°, 8°], and v is the flow velocity at the end of the spillway downward-firing picket (3) under the condition of the maximum discharge flow rate.

2. The flip bucket according to claim 1, wherein A side aeration sill (4) is provided on the inner wall of the side wall (2) where the plunge bucket is connected to the spillway. The side aeration sill (4) is of the sudden expansion type, and the sudden expansion width b1 has a value range of [0.20 m, 0.40 m].

3. The ski-jump bucket according to claim 1, wherein The flip angle θ of the plunge bucket (3) has a value range of [-10°, -30°].

4. The flip bucket according to claim 1, characterized in that, The difference Δh between the elevation of the end of the plunge bucket (3) and the highest downstream water level is less than 10 m.

5. The ski-jump bucket according to claim 1, wherein, The diffusion angle α1 of the left side wall of the plunge bucket (3) has a value range of [1°, 7°].

6. The flip bucket according to claim 1, characterized in that The diffusion angle α2 of the right side wall of the plunge bucket (3) has a value range of [1°, 7°].

7. The flip bucket according to claim 1, characterized in that, The contraction angle β of the dentate sill has a value range of [0°, 10°].

8. The ski-jump bucket according to claim 1, characterized in that, The dentate sills in the group of dentate sills are arranged in a regularly alternating pattern of large and small sizes; or, the dentate sills in the group of dentate sills are arranged with several large dentate sills in the middle and several small dentate sills symmetrically arranged on both sides.

9. The ski-jump bucket according to claim 1, wherein, The drop ΔZ between the group of dentate sills and the bottom plate of the downstream river channel is greater than 20.0 m.

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