A fishway inlet flow rate regulating structure and design method

Abstract

The present invention provides a flow rate regulating structure and design method for a fishway inlet, and relates to the technical field of fishway design, including a fishway inlet, a flow rate regulating buoy, a slide, a working gate, a fishway pool and a fishway partition. The flow rate regulating buoy is slidably connected to the slide, and the working gate is installed at the fishway inlet near the left side of the flow rate regulating buoy. The present invention can adapt to a wider range of river water level fluctuations by designing a single or a few fishway inlets, can effectively reduce the number of fishway inlets, and significantly reduce engineering investment. The inlet flow rate of the fishway inlet can be fully adjusted only by controlling the number of buoys, is easy to control during actual operation, and can play a good role in attracting fish. A new type of single inlet flow rate regulating structure that can adapt to large downstream water level fluctuations and a simple and reliable design method are also proposed. Compared with other types of structures and design methods, the effect is better and the promotion and application prospects are broad.

Description

Technical Field

[0001] The invention relates to the technical field of fishway design, and in particular to a fishway inlet flow rate regulating structure and a design method. Background Art

[0002] The design of the fishway inlet is crucial, including the flow rate and water depth at the fishway inlet. Theoretical studies have shown that a relatively high velocity water flow is usually used at the fishway inlet to attract fish. In the actual operation of the fishway, the flow rate inside the fishway varies in a small range, the average flow rate of the cross section is low, and the flow rate is uniform, so it is difficult to form a velocity advantage and a good fish-attracting effect near the inlet. When the water flow velocity in the fishway inlet area is lower than the fish sensing velocity, water replenishment or the use of a method in which the water depth of the fishway pool is higher than the water depth of the inlet river channel to create a local waterfall to form a velocity advantage is often adopted to induce fish to enter the fishway.

[0003] Especially when the water level fluctuation of the downstream river channel is large and the arrangement conditions of the number of fishway inlets are limited, one inlet often has to withstand a large water level fluctuation, but the water depth and flow rate of the fishway pool are limited, which often causes the river channel water depth to be close to or greater than the water depth of the fishway pool, forming local water congestion inside the fishway or at the outlet, thereby reducing the outflow velocity of the fishway inlet, making it difficult for the water flow to form a flow velocity advantage, and the fish luring effect becomes poor, affecting the normal use of the fishway. Based on this, the present invention designs a fishway inlet flow velocity adjustment structure and design method to solve the above problems. Summary of the invention

[0004] The object of the present invention is to provide a fishway inlet flow rate regulating structure and design method to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a flow rate regulating structure at a fishway inlet, comprising a fishway inlet, a flow rate regulating buoyancy box, a slide, a working gate, a fishway pool chamber and a fishway partition, the slide being arranged on both sides of an inner cavity of the fishway inlet, the flow rate regulating buoyancy box being slidably connected to the slide, the working gate being installed at a position at the fishway inlet close to the left side of the flow rate regulating buoyancy box, the fishway partition being provided with a plurality of groups and being evenly distributed on the left side of the working gate, and the fishway pool chamber being arranged between two adjacent groups of the fishway partitions.

[0006] Preferably, the flow rate regulating buoyancy box is composed of a plurality of small buoyancy box components, a water inlet is provided on the side of the flow rate regulating buoyancy box, and a water outlet is provided on the bottom of the flow rate regulating buoyancy box.

[0007] Preferably, a river channel is provided on the right side of the fishway inlet, and a plurality of flow rate regulating buoys are provided, and the number of the flow rate regulating buoys matches the depth of the river channel.

[0008] Preferably, the water depth inside the fishway chamber is greater than 0.5 m.

[0009] A method for designing a fishway inlet adopts the above-mentioned fishway inlet flow rate regulating structure, comprising the following steps:

[0010] S1: Analyze and calculate and determine the water level-frequency relationship curve near the entrance of the fishway in the downstream river, take the water level with a guaranteed rate of not less than 85% as the design water level, determine the design depth H1 of the fishway entrance bottom plate elevation, and when the fishway works normally, the entrance bottom plate elevation design depth H11;

[0011] S2: According to the requirements of the specification, determine the internal water depth H2 of the pool room that meets the normal operation of the fishway (H2 ≥ 0.5m);

[0012] S3: Determine the geometric parameters of the pontoon. The pontoon is placed in the inlet with a width of B, with a length of b = 2B ~ 4B; the height h is usually 0.5 ~ 1m;

[0013] S4: The total number of working pontoons required for design Float box; operator represents round down;

[0014] S5: Determine the appropriate flow velocity v for attracting fish at the fishway inlet. According to experience, when v is between 0.6 and 1.6 m / s, the fish attracting effect is optimal.

[0015] S6: When the pontoon is far from the fishway chamber, a backflow zone is generated, the water flow is chaotic, and it is not conducive to fish swimming upstream. The pontoon is arranged at a distance a from the first partition of the fishway chamber 5, a = 1.0B ~ 2.5B;

[0016] S7: The fishway buoy is arranged at a distance c from the river channel, where c = 5B to 8B;

[0017] S8: When the water flow rate at the inlet of the fishway does not meet the fish attracting requirements, it is necessary to activate the working buoys. The number of buoys placed during operation Section buoyancy tank.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The present invention can adapt to a wider range of river water level fluctuations by designing a single or fewer fishway inlets, which can effectively reduce the number of fishway inlets and significantly reduce engineering investment. The inlet flow rate of the fishway inlet can be fully adjusted by simply controlling the number of buoys, which is easy to control during the actual operation period and can play a good role in attracting fish.

[0020] (2) The present invention also proposes a new type of single-inlet flow rate adjustment structure that can adapt to large downstream water level fluctuations and a simple and reliable design method. Compared with other types of structures and design methods, it has better effects and has broad prospects for promotion and application.

[0021] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0023] Figure 1 It is a schematic longitudinal section diagram of the fishway inlet of the present invention;

[0024] Figure 2 It is a schematic plan view of the fishway inlet of the present invention;

[0025] Figure 3 It is a schematic elevation diagram of the pontoon of the present invention;

[0026] Figure 4 It is a schematic diagram of flow velocity distribution of the longitudinal section of the centerline of the fishway inlet of a certain calculation condition of the present invention;

[0027] Figure 5 It is a schematic diagram of the flow velocity distribution at the bottom of the fishway in a certain calculation condition of the present invention;

[0028] Figure 6 A schematic diagram of flow velocity distribution in the middle layer of a fishway in a certain calculation condition of the present invention;

[0029] Figure 7 It is a schematic diagram of the surface flow velocity distribution of the fishway under a certain calculation condition of the present invention.

[0030] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0031] 1-fishway inlet, 2-flow rate regulating buoyancy box, 3-slideway, 4-working gate, 5-fishway pool chamber, 6-fishway partition, 7-river channel. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Example 1

[0034] See also Figure 1-7The present invention provides a technical solution: a fishway inlet flow rate regulating structure, comprising a fishway inlet 1, a flow rate regulating buoyancy tank 2, a slide 3, a working gate 4, a fishway pool chamber 5 and a fishway partition 6, the slide 3 is arranged on both sides of the inner cavity of the fishway inlet 1, the flow rate regulating buoyancy tank 2 is slidably connected to the slide 3, the working gate 4 is installed at the fishway inlet 1 near the left side of the flow rate regulating buoyancy tank 2, the fishway partition 6 is provided with multiple groups, and is evenly distributed on the left side of the working gate 4, and the fishway pool chamber 5 is arranged between two adjacent groups of fishway partitions 6.

[0035] The flow rate regulating buoyancy box 2 is composed of a plurality of small buoyancy box components, a water inlet is arranged on the side of the flow rate regulating buoyancy box 2, and a water outlet is arranged on the bottom of the flow rate regulating buoyancy box 2.

[0036] A river channel 7 is provided on the right side of the fishway inlet 1 , and a plurality of flow rate regulating buoyancy tanks 2 are provided, and the number of the flow rate regulating buoyancy tanks 2 matches the depth of the river channel 7 .

[0037] The water depth inside the fishway chamber 5 is greater than 0.5 m.

[0038] A method for designing a fishway inlet adopts the above-mentioned fishway inlet flow rate regulating structure, comprising the following steps:

[0039] S1: Analyze and calculate and determine the water level-frequency relationship curve near the entrance of the fishway in the downstream river, take the water level with a guaranteed rate of not less than 85% as the design water level, determine the design depth H1 of the fishway entrance bottom plate elevation, and when the fishway works normally, the entrance bottom plate elevation design depth H11;

[0040] S2: According to the requirements of the specification, determine the internal water depth H2 of the pool room that meets the normal operation of the fishway (H2 ≥ 0.5m);

[0041] S3: Determine the geometric parameters of the pontoon. The pontoon is placed in the inlet with a width of B, with a length of b = 2B ~ 4B; the height h is usually 0.5 ~ 1m;

[0042] S4: The total number of working pontoons required for design Section buoyancy tank;

[0043] S5: Determine the appropriate flow velocity v for attracting fish at the fishway inlet. According to experience, when v is between 0.6 and 1.6 m / s, the fish attracting effect is optimal.

[0044] S6: When the pontoon is far from the fishway chamber, a backflow zone is generated, the water flow is chaotic, and it is not conducive to fish swimming upstream. The pontoon is arranged at a distance a from the first partition of the fishway chamber 5, a = 1.0B ~ 2.5B;

[0045] S7: The fishway buoy is arranged at a distance c from the river channel, where c = 5B to 8B;

[0046] S8: When the water flow velocity at the inlet of the fishway fails to meet the requirement for attracting fish, it is necessary to activate the working floating box, and the number of floating boxes placed during operation section of floating boxes.

[0047] The length b of the inlet velocity regulating floating box, the distance a between the floating box and the first partition of the inlet pool chamber section, the distance c between the floating box and the river channel, and the number n1 of floating boxes required to be placed during operation. The technical principle of the design method lies in that there are water flow patterns such as jet flow and vortex flow in the fishway, and the contained hydraulic information is relatively rich. In order to comprehensively capture the rich water flow information in the fishway, the water flow situation in the fishway is calculated through a three-dimensional mathematical model. The turbulence model adopted is the k-ε two-equation model. The free surface adopts the VOF method. A function F is defined in space. The whole water content is 1, and the water-free content is 0. When it is the free surface, 0 < F < 1. The function F is a function of space and time, that is, F = F(x, y, z, t), which can be understood as the movement of a dyeing point without mass and viscosity that is consolidated on the fluid particle and moves with the fluid. Its transport equation is:

[0048] (1)

[0049] The upstream boundary condition is set as the flow boundary, and the downstream boundary condition is set as the constant water depth; the top boundary of the fishway is set as the pressure inlet, and the relative pressure value is set as 0 so that air can freely enter and exit; the solid boundary adopts the no-slip condition; the turbulent kinetic energy k and the dissipation rate ε at the inlet and outlet are obtained from the empirical formulas (2) and (3):

[0050] (2)

[0051] (3)

[0052] In the formula, L is the turbulent characteristic length; the finite difference method is used for solution.

[0053] Formulate different schemes, fix the upstream flow boundary and the downstream water level boundary, and study the influence of different floating box heights, floating box layout positions, and the number of floating boxes arranged on the water flow conditions. Output the velocity distribution at different elevations of the longitudinal section and plane of the model. The calculation results under a certain working condition are shown in Figures 1 to 4 .

[0054] Through numerical simulation, the calculation and demonstration conclusions are as follows:

[0055] (1) When other conditions are certain, the water flow conditions at the inlet section of the fishway are better when the floating box length is longer. When the floating box length is shorter, a recirculation area is generated at the connection section between the inlet section of the fishway and the fishway pool chamber, and the water flow pattern is relatively chaotic, which is not conducive to the upstream migration of fish. The floating box length is taken as 2 to 4 times the width of the fishway pool chamber 5, b = 2B to 4B;

[0056] (2) When the size of the pontoon is constant and the pontoon is far from the fishway chamber, a backflow zone is generated and the water flow is chaotic, which is not conducive to fish swimming upstream. The pontoon is arranged at a position a away from the first partition of the fishway chamber 5, where a = 1.0B~2.5B;

[0057] (3) When the size and location of the pontoon are constant, the different lengths of the fishway inlet section have little effect on the flow conditions. Considering the layout of the fishway pontoon at a distance c from the river channel, c = 5B~8B;

[0058] (4) When other conditions are constant, the height of the pontoon is relatively low, which does not significantly improve the flow velocity at the inlet section. When the height of the pontoon is relatively high, the flow velocity at the inlet section is too high, and the flow velocity distribution is not conducive to fish upstream. The number of pontoons placed during operation is The buoyancy box is well maintained and the flow conditions are good.

[0059] For a certain project, the water level with a guaranteed rate of not less than 85% is taken as the design fixed water level H1=5.2m; the normal operating water depth inside the fishway pool 5 is determined according to the specification H2=2m; the width of the designed fishway pool 5 is B=2m; the height of the designed pontoon 1 is 0.5m; the total number of working pontoons required for design. The pontoon placement position: a=4m from the first partition of the fishway pool 5 section, c=12m from the river 7; when the water depth of the river 7 changes to H11=3.6m, the number of pontoons is placed.

[0060] Implementation 2

[0061] For a certain project, the water level with a guaranteed rate of not less than 85% is taken as the design fixed water level H1=10.4m; according to the specification, the normal operating water depth inside the fishway pool 5 is determined to be H2=2.5m; the design width of the fishway pool 5 is B=2m; the design height of the pontoon is 1m; the total number of working pontoons required for the design . The pontoon is placed at a = 5m from the first partition of the fishway chamber 5 and c = 14m from the river channel 7. 11 =8.2m, the number of pontoons to be placed .

[0062] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0063] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for designing a fishway inlet, using a fishway inlet flow rate adjustment structure, characterized in that: The fishway inlet flow rate regulating structure comprises a fishway inlet (1), a flow rate regulating buoyancy box (2), a slideway (3), a working gate (4), a fishway pool chamber (5) and a fishway partition (6), wherein the slideway (3) is arranged on both sides of the inner cavity of the fishway inlet (1), the flow rate regulating buoyancy box (2) is slidably connected to the slideway (3), the working gate (4) is installed at a position of the fishway inlet (1) close to the left side of the flow rate regulating buoyancy box (2), a plurality of groups of the fishway partition (6) are provided and are evenly distributed on the left side of the working gate (4), and the fishway pool chamber (5) is arranged between two adjacent groups of the fishway partition (6); The method comprises the following steps: S1: Analyze and calculate and determine the water level-frequency relationship curve near the entrance of the fishway in the downstream river, take the water level with a guaranteed rate of not less than 85% as the design water level, determine the design depth H1 of the fishway entrance bottom plate elevation, and when the fishway works normally, the entrance bottom plate elevation design depth H11; S2: According to the requirements of the specification, determine the water depth H2 inside the pool room that meets the normal operation of the fishway, H2 ≥ 0.5m; S3: Determine the geometric parameters of the pontoon; the pontoon is placed in the inlet with a width of B, with a length of b = 2B ~ 4B; the height h is 0.5 ~ 1m; S4: The total number of working pontoons required for design Section buoyancy tank; S5: Determine the appropriate flow velocity v for attracting fish at the fishway inlet. According to experience, when v is between 0.6 and 1.6 m / s, the fish attracting effect is optimal. S6: When the buoy is far from the fishway chamber, a backflow zone is generated, the water flow is chaotic, and it is not conducive to fish swimming upstream; the buoy is arranged at a position a away from the first baffle of the fishway inlet chamber, a = 1.0B ~ 2.5B; S7: The fishway buoy is arranged at a distance c from the river channel, where c = 5B to 8B; S8: When the water flow rate at the inlet of the fishway does not meet the fish attracting requirements, it is necessary to activate the working buoys. The number of buoys placed during operation Section buoyancy tank.

2. A method for designing a fishway inlet as claimed in claim 1, characterized in that: The flow rate regulating buoy (2) is composed of a plurality of small buoy components, a water inlet is provided on the side of the flow rate regulating buoy (2), and a water outlet is provided at the bottom of the flow rate regulating buoy (2).

3. A method for designing a fishway inlet as claimed in claim 2, characterized in that: A river channel (7) is provided on the right side of the fishway inlet (1), and a plurality of flow rate regulating buoys (2) are provided, and the number of the flow rate regulating buoys (2) matches the depth of the river channel (7).

4. A method for designing a fishway inlet as claimed in claim 3, characterized in that: The water depth inside the fishway chamber (5) is greater than 0.5 m.

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