Fishway with floating type entrance and exit based on diversion tunnel reconstruction

Abstract

The invention belongs to the technical field of water conservancy and hydropower engineering, and particularly relates to a fishway with a floating type entrance and exit based on diversion tunnel reconstruction. The diversion tunnel comprises a diversion tunnel body, and is characterized by further comprising an upstream section and a downstream section, the upstream section comprises a first telescopic pipe and an upstream buoyancy tank, the upstream buoyancy tank is communicated with the upstream end of the diversion tunnel body through the first telescopic pipe, and an upper opening is formed in the upstream buoyancy tank; the downstream section comprises a second telescopic pipe and a downstream buoyancy tank, the downstream buoyancy tank is communicated with the downstream end of the diversion tunnel body through the second telescopic pipe, and the downstream buoyancy tank is provided with an upper opening. The fishway provided by the invention is reconstructed on the basis of the diversion tunnel, and the upstream section and the downstream section both adopt the design of the buoyancy tanks, so that the positions of the entrance and exit of the fishway can better adapt to the changes of upstream and downstream water levels, the scheduling operation is simple and convenient, the complexity and difficulty of operation management are reduced, and the operation efficiency is improved; and the method is more suitable for water conservancy and hydropower engineering with large upstream water level amplitude.

Description

Technical Field

[0001] The invention belongs to the technical field of water conservancy and hydropower engineering, and in particular relates to a fishway with a floating inlet and outlet based on the reconstruction of a diversion tunnel. Background Art

[0002] In order to meet people's needs, large dams have been widely built for water supply, irrigation, power generation, etc. However, while solving water resource problems, these dams also bring some negative impacts to the ecological environment, one of which is the obstruction of fish migration and reproduction.

[0003] In order to reduce obstacles to fish migration and reproduction, people have designed an engineering facility called a fishway; a fishway can be seen as a special channel that provides a path for fish to pass safely.

[0004] It simulates the environment of a natural waterway and guides fish to their destination through a series of structures such as weirs, flumes and channels.

[0005] However, there is a certain fluctuation in water levels upstream and downstream of the dam. Most of the existing fishways adopt a multi-inlet and multi-outlet structural design, while some dams are daily regulation reservoirs and will experience large water level changes within a day. Frequent adjustment of different inlet and outlet gates is not only complicated and uneconomical, but may also have a fatal effect on the fish that are swimming upstream at the inlet and outlet sections. For example, closing a high-water-level outlet gate may cause the fish that have just moved upstream to this section to suffocate and die due to lack of water.

[0006] To solve this problem, most existing fishways use multiple inlets and outlets to adapt to water level fluctuations. The existing solutions are as follows: CN110468806A, CN105484213A and CN210597233U; in addition, the water level at the outlet of the fishway is equal to the downstream water level, and the water level at the inlet of the fishway is equal to the upstream water level. Each inlet and outlet generally has a water level operation range of 0.5-2m. When the fishway is running, if the upstream water level drops or the downstream water level rises, the water level of the fishway may rise step by step along the water surface line, and the flow rate will become slower and slower along the way, making it difficult for fish to find the entrance; Or when the fishway is running, the water level along the fishway gradually decreases due to the rising water level upstream or the decreasing water level downstream, and the flow rate becomes faster and faster along the way, which causes fish fatigue in swimming upstream, which is not conducive to fish swimming upstream. Summary of the invention

[0007] The invention provides a fishway structure capable of self-adapting to upstream water level changes, so as to solve the problems of complex inlet and outlet layout of existing fishways, large workload of scheduling and adjustment, low operating efficiency and poor fish passing effect.

[0008] The present invention is achieved through the following technical solutions: A floating inlet and outlet fishway based on the reconstruction of a diversion tunnel, comprising a diversion tunnel body, an upstream section and a downstream section; The upstream section includes a first telescopic tube and an upstream buoyancy box, the upstream buoyancy box is connected to the upstream end of the diversion tunnel body through the first telescopic tube, and the upstream buoyancy box is provided with an upper opening; The downstream section comprises a second telescopic tube and a downstream buoyancy box. The downstream buoyancy box is communicated with the downstream end of the diversion tunnel body through the second telescopic tube. The downstream buoyancy box is provided with an upper opening.

[0009] In order to better realize the present invention, further optimization is made in the above structure. A plurality of vertical slit baffles are arranged in the diversion tunnel body. The plurality of vertical slit baffles are arranged in sequence along the length direction of the diversion tunnel body. The vertical slit baffles are provided with slits for fish to pass through, and the slits are arranged along the vertical direction.

[0010] In order to better implement the present invention, further optimization is made in the above structure, and a plurality of the vertical seam baffles are arranged equidistantly along the length direction of the diversion tunnel body.

[0011] In order to better realize the present invention, further optimization is made in the above structure, and a functional pool room is formed between two adjacent vertical seam baffles, and the functional pool room includes a rest pool room and a sprint pool room, and the length of the rest pool room is 2-2.5 times the length of the sprint pool room.

[0012] In order to better realize the present invention, further optimization is made in the above structure, the vertical seam baffle includes a left baffle and a right baffle, the left baffle and the right baffle are respectively arranged on both sides of the diversion hole body, and the left baffle and the right baffle are not in the same vertical plane, and the gap between the left baffle and the right baffle on one side close to each other forms the gap.

[0013] In order to better implement the present invention, further optimization is made in the above structure, and a plurality of light sources are arranged on the top of the diversion tunnel body, and the plurality of light sources are arranged at equal intervals along the extension direction of the diversion tunnel body.

[0014] In order to better implement the present invention, further optimization is made in the above structure, the upstream end and the downstream end of the diversion tunnel body are both provided with connecting pipes, and the first telescopic pipe and the second telescopic pipe are sleeved on the connecting pipes through a connecting piece.

[0015] In order to better implement the present invention, further optimization is made in the above structure, the diversion tunnel body is arranged in the multi-year regulating reservoir, and the downstream pontoon is located between the 10% low water level in the dry season and 0.5m below the flood limit water level.

[0016] In order to better realize the present invention, further optimization is made in the above structure, the diversion tunnel body is arranged in the daily regulating reservoir, and the downstream pontoon is located at a position 1m below the flood limit water level.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The fishway provided by the present invention is rebuilt on the basis of a diversion tunnel, and both the upstream section and the downstream section adopt a pontoon design, so that the locations of the inlet and outlet of the fishway can better adapt to the changes in the upstream and downstream water levels, and the scheduling and operation are simple, which reduces the complexity and difficulty of operation management and improves the operation efficiency; it is more suitable for water conservancy and hydropower projects with large upstream water level fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a side view of a fishway with a floating inlet and outlet rebuilt based on a diversion tunnel according to the present invention; Figure 2 It is a cross-sectional view of a fishway with a floating inlet and outlet rebuilt based on a diversion tunnel according to the present invention; Figure 3 It is an axial perspective view of a fishway with a floating inlet and outlet rebuilt based on a diversion tunnel according to the present invention; Figure 4 yes Figure 3 A partial enlarged view of part A in the middle.

[0020] In the figure: 1. Diversion tunnel body; 11. Vertical seam baffle; 2. upstream section; 21. first telescopic tube; 22. upstream buoyancy tank; 3. Downstream section; 31. Second telescopic pipe; 32. Downstream buoyancy tank. DETAILED DESCRIPTION

[0021] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0022] In the description of the present invention, it should be noted that, unless otherwise specified, the meaning of "plurality" is two or more; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0023] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In the prior art, the types of fishways in water conservancy projects include the following: Bionic fishways are suitable for a wide range of fish and are generally selected when the terrain is open and suitable for layout; Baffle-type fishways are suitable for a variety of migratory fish; Trough-type fishways are suitable for fish with strong swimming ability; Special structure fishway, suitable for fish that can crawl, stick and pass through gaps, such as eels; At present, there is no precedent for converting diversion tunnels into fishways. The main difficulties include: control of flow velocity, fish gathering position and lighting.

[0025] Now let's explain in detail the difficulties of converting the diversion tunnel into a fishway: 1. Flow rate: Fish swimming ability can be roughly divided into three categories: sustained swimming speed, endurance swimming speed, and breakthrough swimming speed. Fish can remain in sustained swimming mode for considerable periods of time without becoming fatigued; The endurance swimming speed of fish is between the sustained swimming speed and the sprint swimming speed. At this speed, lactic acid in the fish is likely to accumulate in large quantities, causing fatigue. The lunge swimming speed is the maximum speed that fish can reach, and it can be maintained for a very short time. If the lunge time is too long, the fish will become fatigued and die.

[0026] When fish swim upstream, their sustained swimming speed, endurance swimming speed and breakthrough swimming speed need to be considered.

[0027] Fish need to pass through a certain range of rapids during the upstream process. At the same time, in order to ensure that the fish have enough physical strength to pass through the fishway, a rest pool (rest pool room) is usually set up in the fishway for them to restore their physical strength.

[0028] 2. Fish gathering location: The selection of fish gathering position plays an important role in the design of fish passage projects (fishways). Relevant studies at home and abroad have shown that whether fish can quickly find and accurately enter the fishway entrance is one of the key factors for the successful operation of the fishway; therefore, the selection of the fishway entrance position in the fishway becomes the key to the success or failure of the operation of fish passage facilities (fishways).

[0029] Specifically, the design of fishway entrances needs to consider the location and orientation of the fishway entrances, the number of entrances, the water flow conditions at the entrances, and the fish intercepting and guiding measures of the fishway.

[0030] In order to ensure the ecological base flow and environmental water requirements, most new projects are equipped with ecological discharge holes or combined with runoff power stations.

[0031] There are often water discharges at spillways, power station tailwaters, etc. Fish tend to gather near the water outlets during migration. This location is an ideal location for arranging the fishway inlet. When the downstream water level is low during the fishing season, the inlet elevation is also correspondingly low, so attention needs to be paid to siltation problems.

[0032] The fishway entrance should be able to adapt to the fluctuation of downstream water levels to ensure that there is a certain water depth at the fishway entrance during the fishing season.

[0033] The following requirements are imposed on the selection of fishway exit locations: (1) It must be able to adapt to changes in the upstream water level. During the fishing season, when the water level on the dam changes, it must be able to ensure that the fishway outlet has sufficient water depth and is well connected to the reservoir water surface; (2) The outlet should be far away from the powerhouse and sluice gate to prevent the fish that have successfully migrated upstream from the water from being carried back downstream; (3) The outlet should be close to the shore, and the water flow outside the outlet should be smooth, with a clear flow direction and no whirlpools, so that fish can smoothly swim upstream along the water flow and the shoreline; (4) The outlet should be far away from areas with polluted water and areas that may disturb or threaten fish; (5) The exit of the fishway faces the direction of the upstream water flow, making it easier for fish to swim out of the fishway.

[0034] 3. Lighting: The phototaxis of fish is a stress response and the result of long-term natural selection. Freshwater fish generally have phototaxis, which can be roughly divided into the following four points: (1) When fish see light in the water, they will feel "curious" and produce an exploratory conditioned reflex to move toward the light source; (2) They move toward light sources to feed. For example, larval zooplankton such as copepods, small shrimps, and small crabs in the water have a very strong tendency to move toward light when illuminated by light and gather in the light source area, causing foraging fish to swim toward the zooplankton migration area to find the best food. (3) Fish instinctively move toward the light that suits them; (4) When exposed to light, the fish's photoreceptors receive light energy, causing their visual pigments to undergo photochemical reactions and swim toward the light source.

[0035] Therefore, if the diversion tunnel is converted into a fishway, additional light sources must be provided, otherwise the fish will stagnate, greatly reducing the efficiency of fish passage.

[0036] The present embodiment provides a floating inlet and outlet fishway based on the reconstruction of the diversion tunnel, see Figures 1 to 4 , which comprises a diversion tunnel body 1, an upstream section 2 and a downstream section 3; The upstream section 2 includes a first telescopic tube 21 and an upstream buoyancy box 22. The upstream buoyancy box 22 is connected to the upstream end of the diversion tunnel body 1 through the first telescopic tube 21. The upstream buoyancy box 22 is provided with an upper opening. The downstream section 3 includes a second telescopic tube 31 and a downstream buoyancy box 32. The downstream buoyancy box 32 is connected to the downstream end of the diversion tunnel body 1 through the second telescopic tube 31. The downstream buoyancy box 32 is provided with a lower opening.

[0037] The upstream pontoon 22 and the downstream pontoon 32 can change with the water level when the water level changes, so that fish can always migrate (migrate or swim upstream) through the fishway. The scheduling and operation of the fishway is simple, which reduces the complexity and difficulty of operation management and improves operation efficiency.

[0038] Of course, in order to better meet the requirements of fish passing through the fishway, the position of the upper opening and the position of the lower opening can be adjusted according to the requirements of the above-mentioned fish gathering position, such as: the position of the upper opening is at the water flow outlet (extending the position of the upper opening to the riverbed close to the right bank, so as to attract fish with the high flow rate of the downstream water of the flood discharge gate); The lower opening should be located away from the powerhouse and sluice gate, and close to the shore so that fish can better complete their migration.

[0039] At the same time, in order to better design it into an ecological fishway and control the water flow rate, a plurality of vertical seam baffles 11 are arranged in the upstream section 2, see Figure 2 and Figure 3 , a plurality of vertical seam baffles 11 are arranged along the length direction of the diversion tunnel body 1; wherein the gaps of the vertical seam baffles 11 are arranged along the vertical direction, see Figure 4, so as to better control the water flow rate, and when fish swim through the diversion hole body 1, they can pass through the vertical slit baffle 11 through the gap; In addition, a plurality of vertical seam baffles 11 divide the diversion tunnel body 1 into a plurality of functional pool chambers, see Figure 2 ;in, The functional pool chamber includes a rest pool chamber and a sprint pool chamber. The sprint chamber has a short length and a higher water flow rate than the rest pool chamber, which is convenient for fish to pass quickly. The length of the rest pool is 2-2.5 times that of the sprint pool, so that the turbulent kinetic energy of the water flow in the rest pool is small and the dissipation rate is also small, that is, the water flow velocity is slower than that of the sprint pool, so that fish can rest during migration.

[0040] Optimally, pressure gate plates are provided at the upper opening and the lower opening. When the pontoons (the upstream pontoon 22 and the downstream pontoon 32) sink into the water, the pressure generated by the water body will push the pressure gate plates open, allowing the water body and fish to enter the pontoons and enter and exit the fishway.

[0041] Optimally, the upstream and downstream ends of the diversion tunnel body 1 are both provided with connecting pipes, and the first telescopic pipe 21 and the second telescopic pipe 31 are respectively sleeved on the connecting pipe at the upstream end and the connecting pipe at the downstream end of the diversion tunnel body 1, and are locked and fixed by connecting pieces, so that the installation of the first telescopic pipe 21 and the second telescopic pipe 31 is more convenient. Preferably, the first telescopic pipe 21 and the second telescopic pipe 31 are both corrugated pipes with tensile strength.

[0042] Optimally, in order to better guide fish migration, a plurality of light sources are provided on the diversion hole body 1, and the plurality of light sources are arranged at equal intervals along the extension direction of the diversion hole body 1, so that the fish can complete migration by following the light sources.

[0043] Preferably, the above-mentioned multiple light sources are arranged at intervals of 5 m in sequence, and the light color and light intensity can be arranged based on specific results obtained by studying the preferences of fish passing through the river.

[0044] Optimally, in order to prevent the young fish from getting lost when descending, a fish attracting device can be provided at the opening position of the downstream section 3 to guide the young fish to locate the opening position of the downstream section 3 smoothly and quickly, thereby improving the descending efficiency of the young fish.

[0045] Preferably, the above-mentioned fish attracting device includes non-structural fish attracting measures such as fish guide fences and / or bubble curtains that do not cause damage to fish.

[0046] The fishway provided by the present invention is rebuilt on the basis of the original diversion tunnel, and is connected with the downstream and upstream of the dam through the upstream section 2 and the downstream section 3 respectively, so that bottom fish can find the fishway along the riverbed; the construction of the fishway avoids excavation of the mountain, protects the environment, and saves a lot of manpower, material resources and financial resources, and saves the cost of separately designing and constructing the fishway to the maximum extent.

[0047] For a multi-year regulating reservoir, the lower opening bottom elevation is 0.5 m below the lower water level of the 10% low water level in the dry season and the flood limit water level, that is, the downstream pontoon 32 is located between the 10% low water level in the dry season and the position 0.5 m below the flood limit water level; For the daily regulating reservoir, the lowest elevation of the lower opening is 1 m below the flood limit water level, that is, the downstream pontoon 32 is located at a position 1 m below the flood limit water level.

[0048] In order to better illustrate the effect of the fishway, the following physical model test was carried out based on the structure of the fishway: The maximum flow velocity on the outlet surface of the diversion tunnel body 1 is set to 1.5m / s, and the water surface fluctuation is small. It is proposed to arrange buoys (upstream buoys 22 and downstream buoys 32) at the inlet and outlet of the diversion tunnel body 1 to adjust the flow rate and greatly reduce the flow velocity in the diversion tunnel body 1. The buoys are suspended in the water, and the water surface in the box is slightly lower than the upstream water level. Combined with the size of the fish passing object, the width of the gap is taken as 0.3m; the net width of the diversion tunnel body 1 depends on the amount of fish passing and the size of the fish, and the original width is still retained as 8m; The length of the functional pool is closely related to the energy dissipation effect of the water flow and the resting conditions of the fish. A longer resting pool has better water flow conditions and a larger resting area, which is beneficial for fish passage. After comprehensive consideration, the length of the resting pool is 3m; the water depth of the fishway should generally not be less than 2.5 times the body length of the main fish passage object. After comprehensive consideration, the water depth of the fishway is 1.5-2.0m; The principles for setting up the rest pool room are as follows: A rest pool is set up every 10-20 vertical seam baffles 11. The rest pool room should be flat-bottomed. The fishway structure adopts a vertical seam combined fishway with a rectangular cross-section, a water depth of 1.5-2.0m, a net width of 8m, a sprint pool room of 3m, and a rest pool room of 6.5m long. The fishway adopts a reinforced concrete structure, and buried stone concrete is used inside to increase the roughness of the fishway, thereby achieving a near-natural effect.

[0049] Generally speaking, the net width of the fishway depends on the amount and size of the fish passing through. Generally, the net width can be 10 times the vertical seam width, that is, 3m. Since the present invention converts the diversion tunnel into a fishway, the width is not changed.

[0050] For the design of the pontoon, specifically: a 3m wide square area is reserved in the middle and lower areas of the inlet and outlet sections of the diversion tunnel for fish passage, and the rest is sealed with concrete and connected to the pontoon through a 3m wide flexible pipe (corrugated pipe).

[0051] The pontoon is a hollow cubic floating structure. The size of the cavity inside the pontoon is 3*3*5m, and the width of the outer cube is 5m. The two are nested, and the gap between the outer cube and the inner cavity is filled with concrete. The concrete wall thickness is 0.5m. The outer surface is plastered with concrete to form a cavity in the middle, which is a jacketed hollow structure to prevent the pontoon from sinking, and part of it is submerged in water to facilitate fish to enter and exit the pontoon through the opening.

[0052] According to calculations, the pontoon is in a floating state, and the water depth inside the pontoon is 1.625m, which meets the conditions for fish to pass through and can save flow for power generation. When the water depth downstream is low during the dry season, the water depth is lower than 2.625m, the pontoon sinks, the flow increases, and the fish can pass through normally.

[0053] According to the above physical model, two different working conditions of upstream water level change were numerically simulated; Working condition 1: Simulate the situation where the upstream and downstream water levels are roughly equal; The upstream water flow velocity is set to 0.13m / s, and the water surface fluctuation is small. Measures are proposed to arrange pontoons upstream of the original diversion tunnel to adjust the flow and greatly reduce the flow velocity in the fishway. The pontoons are suspended in the water, and the water surface in the pontoons is slightly lower than the upstream water level. The size of the upstream pontoon 22 is 2m*2m*2m, and the size of the downstream pontoon 32 is 2m*2m*2m, simulating the working condition when the upstream reservoir water level is equal to the downstream water level. A retractable pipe is connected behind the pontoon. The anti-arc section of the first telescopic pipe 21 is 60° to the vertical direction, and the anti-arc section of the second telescopic pipe 31 is 30° to the vertical direction to adapt to the situation when the upstream and downstream water levels change. The ends of the pipes (the first telescopic pipe 21 and the second telescopic pipe 31) are smoothly transitioned by the retaining walls at both ends in a twisted surface manner and are connected to the gate-shaped section of the original diversion tunnel inlet. The original diversion tunnel is converted into a fishway fish passage section after the construction of the water conservancy project, and a vertical seam baffle 11 is set in this section.

[0054] Considering the size of the fish, the vertical slit width is 0.3m; the net width of the fishway depends on the amount of fish passing through and the size of the fish; The length of the functional pool chamber is closely related to the energy dissipation effect of the water flow and the resting conditions of the fish. A longer resting pool chamber has better water flow conditions and a larger resting area, which is beneficial for fish passage. After comprehensive consideration, the length of the sprint pool chamber is 1.5m; after comprehensive consideration, the water depth of the fishway is 1.5-2.0m; the resting pool chamber should have a flat bottom. The fishway structure of this project adopts a vertical seam combined fishway with a city gate-shaped cross-section and a fishway section length of 11m.

[0055] Use the finite element analysis method to divide the grid, and set the inlet flow rate of condition 1 to 50m3 / s, corresponding to an inlet flow rate of 0.13m / s, a number of sections are divided between the first telescopic tube 21, the second telescopic tube 31 and the different vertical slit baffles 11 of the diversion tunnel body 1, among which the fishway diversion tunnel body 1 is densely divided, focusing on detecting whether the flow rate meets the fish passing condition; Finite element calculations combined with the calculation cloud map show that when vertical seam baffles 11 are set every 1 m in the diversion tunnel body 1, the maximum value of the composite flow velocity in the longitudinal section of the city gate tunnel-shaped river channel in the fishway pool room between the front and rear vertical seam baffles 11 is 0.57 m / s, and the average value is 0.32 m / s, which meets the requirements for the design flow velocity in the fishway in the current "Guidelines for the Design of Fishways for Water Conservancy and Hydropower Projects". Therefore, the retractable improved fishway scheme based on the original diversion tunnel and suitable for different upstream water levels is feasible.

[0056] Condition 2: Simulates the situation where the upstream water level rises and is greater than the downstream water level; The upstream water flow velocity is set to 0.27m / s, and the surface wave buoyancy box is suspended in the water, with the water surface in the box slightly lower than the upstream water level. The size of the upstream buoyancy box 22 is 2m*2m*2m, and the size of the downstream buoyancy box 32 is 2m*2m*2m, simulating the working condition when the upstream reservoir water level is greater than the downstream water level. A retractable pipe is connected behind the buoyancy box. The anti-arc section of the first telescopic pipe 21 is 15° to the vertical direction, and the anti-arc section of the second telescopic pipe 31 is 45° to the vertical direction to adapt to the situation when the upstream and downstream water levels change. The ends of the pipes (the first telescopic pipe 21 and the second telescopic pipe 31) are smoothly transitioned by the retaining walls at both ends in a twisted surface manner, and are connected to the gate-shaped section of the original diversion tunnel inlet. The original diversion tunnel is converted into the current fishway fish passage section through the construction of the water conservancy project, and a vertical seam baffle 11 is set in this section.

[0057] Taking into account the size of the fish passing through, the width of the vertical slit is taken as 0.3m; the net width of the fishway depends on the amount of fish passing through and the size of the fish; the length of the functional pool chamber is closely related to the energy dissipation effect of the water flow and the resting conditions of the fish. A longer pool chamber has better water flow conditions and a larger resting area, which is beneficial for fish passing through. After comprehensive consideration, the length of the sprint pool chamber is taken as 1.5m; after comprehensive consideration, the water depth of the fishway is taken as 1.5-2.0m; the rest pool should be flat-bottomed. The fishway structure of this project adopts a vertical slit combined fishway with a city gate-shaped cross-section and a fishway section length of 11m.

[0058] The same finite element analysis method is used to divide the grid. The inlet flow rate of condition 2 is set to 150m 3 / s, corresponding to an inlet flow rate of 0.27m / s, a number of sections are respectively divided between the first telescopic tube 21, the second telescopic tube 31 and the different vertical seam baffles 11 of the diversion tunnel body 1, wherein the diversion tunnel body 1 of the fishway is densely divided, and the flow rate is mainly detected to see whether it meets the fish passing condition; Finite element calculations combined with the calculation cloud map show that when vertical seam baffles 11 are set every 1 m in the fishway section, the maximum value of the composite flow velocity in the city gate tunnel-shaped longitudinal section in the sprint pool room between the front and rear vertical seam baffles 11 is 0.67 m / s, and the average value is 0.48 m / s, which meets the requirements for the design flow velocity in the fishway in the current "Guidelines for the Design of Fishways for Water Conservancy and Hydropower Projects". Therefore, the retractable improved fishway scheme based on the original diversion tunnel and suitable for different upstream water levels is feasible.

[0059] In addition, the downstream section 3 serves as a transition to the vertical seam fishway section of the traditional reinforced concrete structure, forming a transition buffer section from rigid to flexible. When the second telescopic tube 31 is connected to the river channel, it creates a same natural environment, which can further reduce the stress response of fish to sudden changes in the natural environment, allowing fish to pass through the river channel more naturally and allow the telescopic tube 31 to enter the fishway section.

[0060] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A floating inlet and outlet fishway based on the reconstruction of a diversion tunnel, comprising a diversion tunnel body, characterized in that: It also includes upstream and downstream sections; The upstream section includes a first telescopic tube and an upstream buoyancy box, the upstream buoyancy box is connected to the upstream end of the diversion tunnel body through the first telescopic tube, and the upstream buoyancy box is provided with an upper opening; The downstream section includes a second telescopic tube and a downstream buoyancy box. The downstream buoyancy box is connected with the downstream end of the diversion tunnel body through the second telescopic tube. The downstream buoyancy box is provided with a lower opening.

2. The fishway according to claim 1, characterized in that: A plurality of vertical baffles are arranged in the diversion hole body, and the plurality of vertical baffles are arranged in sequence along the length direction of the diversion hole body. The vertical baffles are provided with gaps for fish to pass through, and the gaps are arranged in the vertical direction.

3. The fishway according to claim 2, characterized in that: The plurality of vertical seam baffles are arranged equidistantly along the length direction of the diversion tunnel body.

4. The fishway according to claim 3, characterized in that: A functional pool room is formed between two adjacent vertical seam baffles, and the functional pool room includes a rest pool room and a sprint pool room. The length of the rest pool room is 2-2.5 times the length of the sprint pool room.

5. The fishway according to claim 4, characterized in that: The vertical seam baffle comprises a left baffle and a right baffle, which are respectively arranged on both sides of the diversion tunnel body, and the left baffle and the right baffle are not in the same vertical plane, and the gap between the left baffle and the right baffle on one side close to each other forms the seam.

6. The fishway according to claim 1, characterized in that: A plurality of light sources are arranged on the top of the diversion tunnel body, and the plurality of light sources are arranged at equal intervals along the extension direction of the diversion tunnel body.

7. The fishway according to claim 1, characterized in that: The upstream end and the downstream end of the diversion tunnel body are both provided with connecting pipes, and the first telescopic pipe and the second telescopic pipe are sleeved on the connecting pipes through connecting pieces.

8. The fishway according to claim 1, characterized in that: The diversion tunnel is arranged in a multi-year regulating reservoir, and the downstream buoyancy box is located between a 10% low water level in the dry season and a position 0.5 m below the flood limit water level.

9. The fishway according to claim 1, characterized in that: The diversion tunnel is arranged in the daily regulating reservoir, and the downstream pontoon is located at a position 1m below the flood limit water level.

Images