Fishway based on reconstruction of diversion tunnel and floating inlet and outlet

Abstract

The application belongs to the technical field of water conservancy and hydropower engineering, and particularly relates to a fishway with a floating inlet and outlet based on reconstruction of a diversion tunnel; the fishway comprises a diversion tunnel body, and is characterized in that: the fishway further comprises an upstream section and a downstream section; the upstream section comprises a first telescopic pipe and an upstream floating box, the upstream floating box is communicated with an upstream end of the diversion tunnel body through the first telescopic pipe, and the upstream floating box is provided with an upper opening; the downstream section comprises a second telescopic pipe and a downstream floating box, the downstream floating box is communicated with a downstream end of the diversion tunnel body through the second telescopic pipe, and the downstream floating box is provided with an upper opening. The fishway is reconstructed on the basis of the diversion tunnel, and the upstream section and the downstream section are both designed as floating boxes, so that the position of the inlet and outlet of the fishway can better adapt to changes in upstream and downstream water levels, operation and scheduling are simple, the complexity and difficulty of operation and management are reduced, and the operation efficiency is improved; the fishway is more suitable for water conservancy and hydropower engineering with large amplitude of upstream water level.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of water conservancy and hydropower engineering, and particularly relates to a floating type inlet and outlet fishway based on reconstruction of a diversion tunnel. BACKGROUND

[0002] To meet the needs of people, large dams are widely built for water supply, irrigation, and power generation, etc. However, these dams, while solving water resource problems, also bring some negative impacts on the ecological environment, one of which is the hindrance to fish migration and reproduction.

[0003] In order to reduce the hindrance to fish migration and reproduction, people have designed an engineering facility called fishway; fishway can be regarded as a special channel, which provides a safe path for fish.

[0004] It simulates the environment of natural waterways and guides fish to the destination through a series of weirs, water tanks and channels, etc.

[0005] However, there is a certain water level fluctuation between the upstream and downstream of the dam, and most existing fishways adopt a multi-inlet and multi-outlet structural design form, and some dams are daily regulated reservoirs, which will have a large water level change within a day. Frequent adjustment of different inlet and outlet gates not only has a complex procedure, is not economical, but also may have a fatal impact on the fish that is ascending in the inlet and outlet section, such as closing a high water level outlet gate, which will cause the fish that just ascends to this section to suffocate due to lack of water.

[0006] To solve this problem, most existing fishways adopt a multi-inlet and multi-outlet design to adapt to the water level fluctuation, and the existing solutions are as follows: CN110468806A, CN105484213A and CN210597233U. In addition, the outlet water level of the fishway is equal to the downstream water level, and the inlet water level of the fishway is equal to the upstream water level, and each inlet and outlet generally has a water level operating range of 0.5-2m fluctuation. For example, when the fishway is running, if the upstream water level decreases or the downstream water level increases, the fishway operating water level may cause the water surface line to gradually rise along the way, and the flow velocity to gradually slow down along the way, thereby causing the fish to have difficulty finding the inlet;

[0007] or, for example, when the fishway is running, if the upstream water level rises or the downstream water level decreases, the fishway operating water level may cause the water surface line to gradually decrease along the way, and the flow velocity to gradually increase along the way, thereby causing the fish to be tired of ascending. SUMMARY

[0008] The present application provides a fishway structure that can adapt to changes in upstream water level, to solve the problems of complex inlet and outlet arrangement, large adjustment workload, low operation efficiency and poor fish passing effect of existing fishways.

[0009] The application is achieved by the following technical solutions:

[0010] A fishway based on reconstruction of a diversion tunnel and comprising a diversion tunnel body, an upstream section and a downstream section;

[0011] The upstream section comprises a first telescopic pipe and an upstream floating box, the upstream floating box being in communication with the upstream end of the diversion tunnel body through the first telescopic pipe, and the upstream floating box being provided with an upper opening;

[0012] The downstream section comprises a second telescopic pipe and a downstream floating box, the downstream floating box being in communication with the downstream end of the diversion tunnel body through the second telescopic pipe, and the downstream floating box being provided with an upper opening.

[0013] In order to better achieve the application, 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 equidistantly along the length direction of the diversion tunnel body, a slit for fish to pass through is arranged on the vertical slit baffle, and the slit is arranged along the vertical direction.

[0014] In order to better achieve the application, further optimization is made in the above structure, the plurality of vertical slit baffles are arranged equidistantly along the length direction of the diversion tunnel body.

[0015] In order to better achieve the application, further optimization is made in the above structure, a functional pool room is formed between two adjacent vertical slit baffles, the functional pool room comprises a resting pool room and a sprint pool room, and the length of the resting pool room is 2-2.5 times the length of the sprint pool room.

[0016] In order to better achieve the application, further optimization is made in the above structure, the vertical slit baffle comprises a left baffle and a right baffle, the left baffle and the right baffle are arranged on the two sides of the diversion tunnel body respectively, the left baffle and the right baffle are not in the same vertical plane, and the gap between the side close to each other of the left baffle and the right baffle forms the slit.

[0017] In order to better achieve the application, further optimization is made in the above structure, a plurality of light sources are arranged on the top of the diversion tunnel body, and the plurality of light sources are arranged equidistantly along the extension direction of the diversion tunnel body.

[0018] In order to better achieve the application, further optimization is made in the above structure, the upstream end and the downstream end of the diversion tunnel body are both provided with a connecting pipe, and the first telescopic pipe and the second telescopic pipe are sleeved on the connecting pipe through a connecting piece.

[0019] In order to better achieve the application, further optimization is made in the above structure, the diversion tunnel body is arranged in a multi-year regulation reservoir, and the downstream floating box is located between the position between the 10% low water level in the dry season and the position 0.5m below the flood control water level.

[0020] In order to better realize the present application, further optimization is made in the above structure, the diversion tunnel body is arranged in the daily regulation reservoir, and the downstream floating box is arranged at a position 1m below the flood control water level.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] The fishway provided by the present application is reconstructed on the basis of the diversion tunnel, and the upstream section and the downstream section are both designed with floating boxes, so that the positions of the inlet and outlet of the fishway can better adapt to the water level changes of the upstream and downstream, the scheduling operation is simple, the complexity and difficulty of operation management are reduced, and the operation efficiency is improved; and the fishway is more suitable for water conservancy and hydropower projects with large upstream water level amplitude. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0024] Figure 1 is a side view of a floating type inlet and outlet fishway based on a reconstructed diversion tunnel;

[0025] Figure 2 is a sectional view of a floating type inlet and outlet fishway based on a reconstructed diversion tunnel;

[0026] Figure 3 is an axial perspective view of a floating type inlet and outlet fishway based on a reconstructed diversion tunnel;

[0027] Figure 4 is Figure 3 a local enlarged view of A part in

[0028] in the figure:

[0029] 1, diversion tunnel body; 11, vertical seam baffle;

[0030] 2, upstream section; 21, first telescopic pipe; 22, upstream floating box;

[0031] 3, downstream section; 31, second telescopic pipe; 32, downstream floating box. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0033] In the description of this invention, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," 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 the invention 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 the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] In existing technologies, fish passages in hydraulic engineering include the following categories:

[0036] Biomimetic fishways are suitable for a wide range of fish species and are generally chosen when the terrain is open and suitable for placement.

[0037] The partition-type fishway is suitable for a variety of migratory fish species;

[0038] The trough-type fishway is suitable for fish with strong swimming abilities;

[0039] Specially designed fish passages are suitable for fish that can crawl, adhere, and navigate crevices, such as eels.

[0040] Currently, there is no precedent for converting a diversion tunnel into a fishway. The main challenges are controlling the flow rate, the location for fish collection, and the lighting.

[0041] The difficulties in converting the diversion tunnel into a fishway will now be explained in detail:

[0042] I. Flow velocity:

[0043] Fish swimming abilities can be broadly categorized into three types: sustained swimming speed, endurance swimming speed, and burst swimming speed; among these,

[0044] Fish can maintain a continuous swimming pattern for a considerable period of time without feeling fatigued;

[0045] The endurance swimming speed of fish falls between continuous swimming speed and burst swimming speed. At this speed, lactic acid tends to accumulate in large quantities in the fish's body, causing them to feel fatigued.

[0046] The burst speed is the maximum speed that fish can achieve, but it is maintained for a very short time. If the burst speed is too long, the fish will become exhausted and die.

[0047] When fish swim upstream, their sustained swimming speed, endurance swimming speed, and burst swimming speed need to be considered.

[0048] Fish need to pass through a certain range of rapids during their upstream migration. In order to ensure that the fish have enough energy to pass through the fishway, resting pools (resting pool rooms) are usually set up in the fishway to restore their energy.

[0049] II. Fish gathering location:

[0050] The selection of the fish collection location plays an important role in the design of fish passage projects (fishways). Domestic and foreign research shows that whether fish can quickly and accurately find and enter the fishway inlet is one of the key factors for the successful operation of the fishway. Therefore, the selection of the fishway inlet location becomes the key to the success or failure of the operation of fish passage facilities (fishways).

[0051] Specifically, the design of fishway inlets needs to consider the location and orientation of the inlets, the number of inlets, the water flow conditions at the inlets, and fish-blocking measures in the fishway.

[0052] To ensure ecological base flow and environmental water requirements, most new construction projects are equipped with ecological water discharge holes or combined with runoff power stations.

[0053] Spillway gates, power station tailraces, and other places where water frequently flows out are ideal locations for fish to gather near the water outlets during their migration. When the downstream water level is low during the fish migration season, the elevation of the inlet should be correspondingly lower, so attention should be paid to the problem of siltation.

[0054] The fish passage inlet should be able to adapt to the rise and fall of the downstream water level, ensuring that there is a certain water depth at the fish passage inlet during the fish season.

[0055] The following requirements apply to the selection of the fishway exit location:

[0056] (1) To adapt to the changes of upstream water level, in the fish migration season, when the water level of the dam changes, it can ensure that there is enough water depth at the fishway outlet, and it is well connected with the reservoir water surface;

[0057] (2) The outlet should be far away from the powerhouse and the sluice to prevent the fish that have successfully migrated upstream from being carried back downstream by the water flow;

[0058] (3) The outlet should be near the shore, and the water flow outside the outlet should be smooth and clear in direction without eddy, so that fish can smoothly migrate upstream along the water flow and the shore line;

[0059] (4) The outlet should be far away from the area with polluted water quality and disturbing and intimidating to fish;

[0060] (5) The fishway outlet faces the upstream water flow direction, which is convenient for fish to swim out of the fishway.

[0061] Three, lighting:

[0062] The phototaxis of fish is a stress response, which is the result of long-term natural selection. Freshwater fish generally have phototaxis, which can be roughly divided into the following four points:

[0063] (1) Fish will feel "curious" when they see light in the water, and will produce exploratory conditioned reflex to approach the light source;

[0064] (2) Foraging fish will approach the light source, such as copepods, small shrimps and small crabs, and other juvenile animals in the water column have very strong phototaxis and gather in the light source area, so that foraging fish swim to the migration area of the foraging fish to find the best bait;

[0065] (3) Fish instinctively tend to their suitable light;

[0066] (4) The light irradiation makes the photoreceptors of fish obtain light energy, and the visual pigment undergoes photochemical reaction, and the fish swims to the light source.

[0067] Therefore, when the diversion tunnel is rebuilt as a fishway, light source must be supplemented, otherwise fish will stagnate and greatly reduce the fish passage efficiency.

[0068] A floating inlet and outlet fishway based on the reconstruction of a diversion tunnel is provided in the embodiment, which is described with reference to Figures 1 to 4 which comprises a diversion tunnel body 1, an upstream section 2 and a downstream section 3;

[0069] The upstream section 2 comprises a first telescopic pipe 21 and an upstream floating box 22, the upstream floating box 22 is communicated with the upstream end of the diversion tunnel body 1 through the first telescopic pipe 21, and the upstream floating box 22 is provided with an upper opening;

[0070] The downstream section 3 comprises a second telescopic pipe 31 and a downstream floating box 32, the downstream floating box 32 is communicated with the downstream end of the diversion tunnel body 1 through the second telescopic pipe 31, and the downstream floating box 32 is provided with a lower opening.

[0071] The upstream floating box 22 and the downstream floating box 32 can change with the water level when the water level changes, so that the fish can always migrate (migrate or upstream) through the fishway, and the scheduling operation of the fishway is simple, which reduces the complexity and difficulty of operation management and improves the operation efficiency.

[0072] Of course, in order to better meet the requirements of fish (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 fish collecting position, such as: the position of the upper opening is at the outlet of the flow (the position of the upper opening is extended to the riverbed near the right bank, that is, the fish can be attracted by the large flow rate of the discharge flow of the flood discharge gate);

[0073] The position of the lower opening is away from the powerhouse and the water discharge gate, and the position of the lower opening is near the bank, so that the fish can better complete the migration.

[0074] At the same time, in order to better design it as a bionic ecological fishway and control the flow rate of the water body, a plurality of vertical slit baffles 11 are arranged in the upstream section 2, see Figure 2 and Figure 3 The plurality of vertical slit baffles 11 are arranged along the length direction of the diversion tunnel body 1; wherein the slit of the vertical slit baffle 11 is arranged along the vertical direction, see Figure 4 to better control the flow rate of the water body, and the fish can pass through the vertical slit baffle 11 through the slit when swimming through the diversion tunnel body 1;

[0075] In addition, the plurality of vertical slit baffles 11 divide the diversion tunnel body 1 into a plurality of functional pool rooms, see Figure 2 ; wherein,

[0076] The functional pool room comprises a resting pool room and a sprint pool room, the length of the sprint is small, and the flow rate of the water flow is greater than that of the resting pool room, which facilitates the fish to pass through quickly;

[0077] The length of the resting pool room is 2-2.5 times the length of the sprint pool room, so that the water flow turbulent energy of the resting pool room is small, and the dissipation rate is also small, that is, the flow rate of the water flow is slower than that of the sprint pool room, so as to facilitate the fish to rest during the migration process.

[0078] Optimization, the upper opening and the lower opening of the above-mentioned are provided with pressure door plates, when the floating box (upstream floating box 22 and downstream floating box 32) sinks into the water, the pressure generated by the water body will push the pressure door plates away, so that the water body and the fish can enter the floating box and in and out of the fishway.

[0079] The upstream end and the downstream end of the diversion tunnel body 1 are provided with connecting pipes, the first telescopic pipe 21 and the second telescopic pipe 31 are sleeved on the connecting pipes at the upstream end and the downstream end of the diversion tunnel body 1 respectively, and are locked and fixed through the 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 corrugated pipes with tensile strength.

[0080] Optimized, in order to better guide fish migration, a plurality of light sources are arranged on the diversion tunnel body 1, and the plurality of light sources are arranged at equal intervals along the extension direction of the diversion tunnel body 1, so that fish can follow the light source to complete migration.

[0081] Preferably, the plurality of light sources are arranged at intervals of 5m, and the light color and light intensity can be arranged according to the preference of fish passing through the river.

[0082] Optimized, in order to avoid the loss of direction of juvenile fish when descending, a fish attracting device can be arranged at the opening position of the downstream section 3 to guide juvenile fish to smoothly and quickly locate the opening position of the downstream section 3, thereby improving the descending efficiency of juvenile fish.

[0083] Preferably, the fish attracting device includes a fish guiding grid and / or a non-structural fish attracting measure such as a bubble curtain which does not cause damage to fish.

[0084] The fishway provided by the present application is reconstructed on the basis of the original diversion tunnel, which 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, saves a lot of manpower, material resources and financial resources, and maximizes the cost saving of separately designed and excavated fishway.

[0085] For a multi-year regulation reservoir, the lower opening bottom elevation is 0.5m below the lower water level of 10% in dry season and the lower water level of flood limit, that is, the downstream floating box 32 is located between the position of 0.5m below the lower water level of 10% in dry season and the lower water level of flood limit.

[0086] For a daily regulation reservoir, the lowest elevation of the lower opening is 1m below the lower water level of flood limit, that is, the downstream floating box 32 is located at a position of 1m below the lower water level of flood limit.

[0087] In order to better illustrate the effect of the fishway, the following physical model test is carried out according to the structure of the fishway:

[0088] The flow velocity of the surface of the outlet of the diversion tunnel body 1 is set to be less than 1.5 m / s, and the water surface fluctuation is small. The measures of arranging the floating box (upstream floating box 22 and downstream floating box 32) at the inlet and outlet of the diversion tunnel body 1 are proposed to adjust the flow, greatly reduce the flow velocity in the diversion tunnel body 1, and suspend the floating box in water. 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 0.3 m. The net width of the diversion tunnel body 1 depends on the amount of fish passing and the size of the fish passing, and the original width is still kept unchanged at 8 m.

[0089] The length of the functional pool chamber is closely related to the flow energy dissipation effect and the resting condition of fish. The longer the resting pool chamber, the better the flow condition, the larger the resting water area, and the more beneficial to the fish passing. The length of the resting pool chamber is considered to be 3 m. The water depth of the fishway is generally not less than 2.5 times the body length of the main fish passing object. After comprehensive consideration, the water depth of the fishway is taken to be 1.5-2.0 m.

[0090] The setting principle of the resting pool chamber is as follows:

[0091] A resting pool is arranged every 10-20 vertical slit baffles 11. The resting pool chamber is preferably flat bottomed. The fishway structure form adopts a vertical slit type combined fishway, the section is rectangular, the water depth is 1.5-2.0 m, the net width is 8 m, the sprint pool chamber is 3 m long, and a resting pool chamber is arranged every 9 vertical slit baffles. The resting pool chamber is 6.5 m long. The fishway adopts a reinforced concrete structure form, and the inside is filled with buried stone concrete to increase the roughness of the fishway, so as to achieve a near-natural effect.

[0092] Generally, the net width of the fishway depends on the amount of fish passing and the size of the fish passing. Generally, the net width is 10 times the width of the vertical slit, that is, 3 m. Since the present application is a diversion tunnel reconstruction fishway, the width is not changed.

[0093] For the design of the floating box, specifically, a square area with a width of 3 m is left in the middle and lower regions of the inlet and outlet sections of the diversion tunnel for fish passage, and the rest is blocked with concrete. The floating box is connected with the floating box through a flexible pipeline (corrugated pipe) with a width of 3 m.

[0094] The floating box is a hollow cubic floating body structure. The size of the cavity in the floating box is 3*3*5 m. The outer cube is nested with the inner cavity. The gap between the outer cube and the inner cavity is filled with concrete. The concrete wall thickness is 0.5 m. The outer surface is coated with concrete. The middle forms a cavity, which is a jacketed hollow structure, so that the floating box will not sink, and a part of it is submerged in water, which is convenient for fish to enter and exit the floating box through the opening.

[0095] After calculation, the floating box is in a floating state, and the water depth in the floating box is 1.625 m, which meets the conditions for fish to pass through, and can save flow for power generation. When the water depth in the downstream is low in the dry season, the water depth is less than 2.625 m, then the floating box sinks, the flow increases, and the fish can pass through normally.

[0096] According to the above physical model, the numerical simulation of two different working conditions of upstream water level change is carried out;

[0097] Working condition 1: simulate the case that the upstream and downstream water levels are roughly equal;

[0098] The upstream flow velocity is set to 0.13 m / s, the water surface fluctuation is small, and the measure of arranging floating box in the upstream of the original diversion tunnel is proposed to adjust the flow, which greatly reduces the flow velocity in the fishway. The floating box is suspended in the water, and the water surface in the box is slightly lower than the upstream water level. The size of the upstream floating box 22 is 2m*2m*2m, and the size of the downstream floating box 32 is 2m*2m*2m. The working condition when the upstream reservoir water level is equal to the downstream water level is simulated. The floating box is connected with a telescopic pipe behind it. The first telescopic pipe 21 is 60° to the vertical direction, and 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 end of the pipe (first telescopic pipe 21 and second telescopic pipe 31) is smoothly connected to the original diversion tunnel entrance city gate hole section by two end retaining walls in a twisted surface way. The original diversion tunnel is reconstructed into a fishway fish passing section by hydraulic engineering construction, and vertical slit baffles 11 are arranged in this section.

[0099] Combined with the size of the fish passing fish, the vertical slit width is taken as 0.3m; the net width of the fishway depends on the amount of fish passing and the size of the fish passing;

[0100] The length of the functional pool chamber is closely related to the flow energy dissipation effect and the resting condition of fish. The longer the resting pool chamber, the better the flow condition and the larger the resting water area, which is beneficial to the fish passing. 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 resting pool chamber should be flat bottomed. The fishway structure form of this project adopts vertical slit type combined fishway, and the section is city gate hole shape. The length of the fishway section pool is 11m.

[0101] Using finite element analysis method, mesh is divided, working condition 1 sets the inlet flow as 50m 3 / s, the corresponding inlet flow velocity is 0.13m / s, and several cross sections are divided between the first telescopic pipe 21, the second telescopic pipe 31 and the diversion tunnel body 1 and the different vertical slit baffles 11 respectively. Among them, the fishway diversion tunnel body 1 is densely divided, and the flow velocity is detected whether it meets the fish passing condition;

[0102] Through finite element calculation, combined with the calculation cloud picture, it can be known that when the vertical slit baffles 11 are set every 1m in the diversion tunnel body 1, the maximum value of the synthesized flow velocity in the city gate hole shape riverway longitudinal section in the fishway pool chamber between the front and rear two vertical slit baffles 11 is 0.57m / s, and the average value is 0.32m / s, which meets the requirement of the current "Fishway Design Guidelines for Water Conservancy and Hydropower Engineering" for the design flow velocity in the fishway. Therefore, the telescopic improved fishway scheme based on the original diversion tunnel applicable to different upstream water levels is feasible.

[0103] Working condition 2: simulate the case that the upstream water level rises and is greater than the downstream water level;

[0104] The upstream water flow rate is set to 0.27 m / s, the water surface wave float is suspended in the water, and the water surface in the tank is slightly lower than the upstream water level. The upstream float 22 is 2 m*2 m*2 m in size, and the downstream float 32 is 2 m*2 m*2 m in size. The working condition when the upstream reservoir water level is higher than the downstream water level is simulated. The float is connected to a telescopic pipe. The first telescopic pipe 21 is 15° from the vertical direction, and the second telescopic pipe 31 is 45° from the vertical direction, to adapt to the situation when the upstream and downstream water levels change. The end of the pipe (first telescopic pipe 21 and second telescopic pipe 31) is smoothly connected to the original diversion tunnel entrance city gate hole section by two end retaining walls in a twisted surface manner. The original diversion tunnel is reconstructed into the present fishway section through water conservancy construction. The vertical joint baffle 11 is arranged in this section.

[0105] Combined with the size of the fish passing through the fishway, the vertical joint width is 0.3 m; the fishway net width depends on the amount of fish passing through and the size of the fish passing through; the length of the functional pool chamber is closely related to the flow energy dissipation effect and the resting conditions of fish. Longer pool chamber has better flow conditions, larger resting water area, and is beneficial to fish passing through. After comprehensive consideration, the length of the sprint pool chamber is 1.5 m; after comprehensive consideration, the fishway water depth is 1.5-2.0 m; the resting pool is preferably flat bottomed. The fishway structure of the project adopts a vertical joint type combined fishway, and the section is a city gate hole shape. The pool length of the fishway section is 11 m.

[0106] Similarly, using the finite element analysis method, the grid is divided, and the working condition 2 is set to an inlet flow rate of 150 m 3 / s, corresponding to an inlet flow rate of 0.27 m / s. The first telescopic pipe 21, the second telescopic pipe 31, and the diversion tunnel body 1 are respectively divided into several cross sections between the different vertical joint baffles 11. The fishway diversion tunnel body 1 is densely divided to focus on detecting whether the flow rate meets the fish passing condition;

[0107] Through finite element calculation, combined with the calculation cloud picture, it can be known that when the vertical joint baffle 11 is set every 1 m in the fishway section, the maximum value of the synthesized flow rate in the city gate hole shape longitudinal section in the sprint pool chamber between the front and rear two vertical joint baffles 11 is 0.67 m / s, and the average value is 0.48 m / s, which meets the requirements of the current "Fishway Design Guidelines for Water Conservancy and Hydropower Engineering" for the design flow rate in the fishway. Therefore, the telescopic improved fishway scheme based on the original diversion tunnel is feasible for different upstream water levels.

[0108] In addition, the downstream section 3 plays a transition role for the traditional reinforced concrete structure vertical joint type fishway section, forming a transition buffer section from rigid to flexible. When the second telescopic pipe 31 is connected to the river, a natural environment is created, which can further reduce the stress reaction of fish to the sudden change of the natural environment, so that the fish can pass through the river more naturally and enter the fishway section through the telescopic pipe 31.

[0109] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A floating inlet / outlet fishway based on a diversion tunnel, comprising the diversion tunnel body, characterized in that: It also includes the upstream and downstream sections; The upstream section includes a first telescopic pipe and an upstream pontoon. The upstream pontoon is connected to the upstream end of the diversion tunnel body through the first telescopic pipe. The upstream pontoon is provided with an upper opening, which extends to the riverbed from the right bank. The downstream section includes a second telescopic pipe and a downstream pontoon. The downstream pontoon is connected to the downstream end of the diversion tunnel through the second telescopic pipe. The downstream pontoon is provided with a lower opening, which is located away from the power plant and the spillway gate, and is located near the bank.

2. The fishway according to claim 1, characterized in that: The diversion tunnel is equipped with multiple vertical slit baffles, which are arranged sequentially along the length of the diversion tunnel. The vertical slit baffles have gaps for fish to pass through, and the gaps are arranged vertically.

3. The fishway according to claim 2, characterized in that: Multiple vertical slit baffles are arranged at equal intervals along the length of the diversion tunnel.

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

5. The fishway according to claim 4, characterized in that: The vertical slit 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. The gap between the left baffle and the right baffle on the side closest to each other forms the slit.

6. The fishway according to claim 1, characterized in that: Multiple light sources are installed at the top of the diversion tunnel body, and the multiple 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: Both the upstream and downstream ends of the diversion tunnel are equipped with connecting pipes, and the first telescopic pipe and the second telescopic pipe are connected to the connecting pipe by a connector.

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

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

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