Fishway local section model test method

Abstract

The invention relates to the technical field of fishways, in particular to a fishway local section model test method. The method comprises the following steps: S1, drawing up a preliminary design scheme of the vertical seam type fishway; s2, designing a fishway engineering local section physical model based on the preliminary design scheme; s3, carrying out a fishway local section model test, measuring and evaluating fishway parameters, and finding out standard exceeding fishway parameters and reasons for the standard exceeding of the fishway parameters; and S4, after the reasons in the S3 are improved, the steps S2 to S4 are repeated until all the fishway parameters meet the design requirements, and a pool chamber structure recommendation scheme is formed based on the fishway parameters. According to the fishway local section model test method, the fishway section model test is carried out, parameters exceeding the standard are found, then adjustment is carried out, a pool chamber structure recommendation scheme is formed, and a theoretical experiment basis is provided for enabling a pool chamber, located on the upper stream of an eel way, on a vertical seam type fishway to meet the migration requirements of eels and eriocheir hepuensis.

Description

Technical Field

[0001] The invention relates to the technical field of fishways, and in particular to a local section model test method for fishways. Background Art

[0002] At present, the canal, as an important part of the new land-sea channel, is becoming more and more important. Compared with land transportation, the canal has the advantages of low energy consumption cost, low transportation cost and high transportation efficiency. It opens up a more convenient and economical sea outlet in the inland area, and accelerates the construction of a relatively complete Beibu Gulf port facilities system in accordance with the requirements of building a world-class port and the standards of major coastal ports and international hub ports across the country.

[0003] At present, migratory animals such as eels (including flower eels and eels) and Hepu mitten crabs exist in some canals in my country, including:

[0004] Flower eels are catadromous fish. In winter, their gonads begin to develop near the mouths of rivers and then they enter the deep sea to spawn and reproduce. From March to April every year, young eels begin to enter the estuaries to swim upstream to find food and grow, and live in caves in rivers and streams. Flower eels can climb a certain height to wade through sluice gates to enter mountain streams and valleys. Eels are a type of catadromous migratory fish. They are native to the sea and swim upstream to fresh water to grow up, and then return to the sea to lay eggs. In spring, large numbers of young eels [also called white eels and eel lines] enter the estuaries of rivers from the sea in groups. Male eels grow in the estuaries of rivers; female eels swim upstream to enter the main streams and tributaries of rivers. Hepu mitten crabs are catadromous crustaceans. The larvae metamorphose into crablets, and then swim upstream to grow in rivers.

[0005] After the permanent dams were built on the canal, the original continuous river ecosystem was divided into discontinuous environmental units. The most direct adverse impact on fish was the blocking of the migration channel. In order to ensure the migration of fish in the canal, fishway projects must be set up at the hub. In order to save costs, the outlet (upstream end) of the eel way used for the migration of eels and Hepu mitten crabs is connected to the vertical slit fishway. How to make the pool chamber located upstream of the eel way on the vertical slit fishway also meet the migration requirements of eels and Hepu mitten crabs has become a difficult problem that technicians in this field need to overcome. Summary of the invention

[0006] The purpose of the present invention is to overcome the problem existing in the background technology of how to make the pool chamber located upstream of the eel way on the vertical slot fishway also meet the migratory requirements of eels and Hepu mitten crabs, and to provide a local section model test method of a fishway.

[0007] A fishway local section model test method comprises the following steps:

[0008] S1. Prepare a preliminary design plan for vertical slot fishway;

[0009] S2. Designing a local cross-section physical model of the fishway project based on the preliminary design scheme;

[0010] S3. Conduct a local section model test of the fishway, measure and evaluate the fishway parameters, and find the fishway parameters that exceed the standard and the reasons for the fishway parameters exceeding the standard, wherein the fishway parameters include the water level difference between the upstream and downstream of adjacent chambers, the vertical seam velocity distribution, the flow field distribution in the chamber, the flow pattern in the chamber and the local water flow in the chamber, and measure the average water depth of each chamber, the average water level difference of each chamber, the vertical seam velocity distribution of each chamber, and the flow field distribution in the chamber;

[0011] S4. After improving the reasons in S3, repeat S2-S4 until all fishway parameters meet the design requirements, and form a recommended pool structure plan based on the fishway parameters.

[0012] The present application describes a method for testing a local cross-section model of a fishway, which finds out-of-standard parameters by conducting a cross-section model test of the fishway, and then adjusts them to form a recommended pool structure plan, thereby providing a theoretical experimental basis for making the pool located upstream of the eel way on the vertical slot fishway meet the migratory requirements of eels and Hepu mitten crabs.

[0013] Preferably, the local section physical model of the fishway engineering is designed as a normal model, and the local section physical model of the fishway engineering is designed according to the gravity similarity criterion, and the overall model design of the fishway is checked for geometric similarity, water flow motion similarity and dynamic similarity.

[0014] Preferably, in step S2, based on the preliminary design plan of the vertical slot fishway, the designed bottom slope I of the pool chamber, the average low tide level at the estuary, the operating water level at the vertical slot fishway outlet, and the minimum water depth in the pool chamber are determined; the corresponding upstream design low water level condition of the fishway, the corresponding downstream design low water level condition of the fishway and the most unfavorable design condition are determined, and based on the designed bottom slope I of the pool chamber, the average low tide level at the estuary, the operating water level at the vertical slot fishway outlet, the minimum water depth in the pool chamber, the corresponding upstream design low water level condition of the fishway, the corresponding downstream design low water level condition of the fishway and the most unfavorable design condition, a local section physical model of the fishway project is designed, wherein the most unfavorable design condition is a condition in which the volume of the energy dissipation water body is minimum on the basis of unchanged geometric scale of the pool chamber.

[0015] Preferably, in step S3, when conducting a local section model test of the fishway, the upstream flat water channel and the downstream overflow plate are used to control the upstream and downstream water levels to be constant, and a number of water gauges are arranged along the local section model of the fishway to measure the water level in the pool chamber. The flow field in the pool chamber and the vertical slit flow field are collected at a single point using an acoustic Doppler flow meter.

[0016] Preferably, in step S3, the flow velocity distribution of the vertical seam is evaluated as follows: the flow velocity of at least part of the vertical seams is measured, a plurality of measuring points are arranged at vertical intervals along the water depth on the center line of each vertical seam, and the flow velocity distribution and the average flow velocity of the vertical seam are obtained based on the measuring points; the recommended range of the flow velocity distribution of the vertical seam and the recommended average flow velocity value are obtained based on the swimming ability test results of the target fish species; it is evaluated whether the flow velocity distribution of the vertical seam exceeds the recommended range of the flow velocity distribution of the vertical seam, and whether the average flow velocity of the vertical seam is greater than the recommended average flow velocity value of the vertical seam; the baffle flow velocity coefficient is obtained based on the average flow velocity of the vertical line of the fish-passing vertical seam, the average water level difference of the baffle, the average flow rate of the fishway and the water volume of the pool chamber. and the power dissipation E per unit water volume in the pool chamber, and the baffle velocity coefficient And the unit water power dissipation E of the pool chamber meets the design requirements.

[0017] Preferably, when the vertical seam on the downstream side of the pool chamber or the flow velocity in the pool chamber exceeds the standard, the water depth of the pool chamber is increased and the flow velocity in the pool chamber is reduced.

[0018] Preferably, in step S3, the flow field distribution in the pool chamber is evaluated as follows: a pool chamber is selected to measure its surface flow field distribution, N measuring lines are set along the width of the pool chamber, and L measuring points are arranged along the length of each measuring line; based on the test results of the measuring points, the mainstream entry form, mainstream path, circulation position, integrity of the recirculation zone and the impact of the recirculation zone on fish are evaluated, wherein the recirculation zone influence range K3 and the maximum flow velocity v of the recirculation zone are used to evaluate the impact of the recirculation zone on fish. cmax To quantify the impact of the recirculation zone on fish.

[0019] Preferably, the influence range K3 of the recirculation zone and the maximum flow velocity v of the recirculation zone are cmax To quantify the impact of the recirculation zone on fish, specifically: K3 = L c B c / (LB), where L c is the maximum length of the recirculation zone, B c is the maximum width of the recirculation zone.

[0020] Preferably, the influence range K3 of the reflow zone is 0.12-0.17; and the reflow intensity range is 0.18-0.24 m / s.

[0021] Preferably, when the influence range of the recirculation zone is too large, based on the diversion angle at the vertical seam in the preliminary design scheme, at least a second diversion angle and a third diversion angle are set, and the second diversion angle and the third diversion angle are respectively substituted into the local section physical model of the fishway engineering to form a new local section physical model of the fishway engineering, and a new local section model test of the fishway is carried out to obtain the average flow velocity of the vertical seam at each diversion angle, the maximum flow velocity of the vertical seam, and the minimum flow velocity of the vertical seam, and obtain an optimized structural scheme, wherein the second diversion angle and the third diversion angle are both greater than the diversion angle at the vertical seam in the preliminary design scheme.

[0022] Preferably, the water level difference in the pool chamber, the vertical seam flow velocity distribution and the flow field distribution in the pool chamber are calculated based on the optimized structural scheme, and it is confirmed whether the water level difference in the pool chamber, the vertical seam flow velocity distribution and the flow field distribution in the pool chamber meet the design requirements. If so, the optimized structural scheme is the recommended scheme for the pool chamber structure.

[0023] Preferably, the minimum value of the mainstream flow in the pool chamber and the average flow velocity of the vertical seams are obtained based on the test results of the measuring points, and the energy dissipation rate of the pool chamber is reflected by the ratio of the minimum value of the mainstream flow in the pool chamber to the average flow velocity of the vertical seams to obtain the energy dissipation rate of the pool chamber.

[0024] Preferably, the fishway in the preliminary design of the fishway includes an eel way and a vertical slot fishway, the migratory fish in the eel way include eels and mitten crabs, the migratory fish in the vertical slot fishway include red-eyed trout and dace, one end of the eel way is connected to the middle of the vertical slot fishway, and the other end extends to the bottom of the canal.

[0025] Preferably, the recommended scheme for the pool chamber structure is as follows: a water retaining structure is arranged at intervals in the part of the vertical slot fishway located upstream of the eel way, and a pool chamber is formed between adjacent water retaining structures. The water retaining structure includes a partition and a guide plate arranged opposite to each other, the guide plate is smaller in width than the partition, and a vertical slot for fish to pass through is provided between the partition and the guide plate. A climbing matrix is ​​also provided in the pool chamber, and the climbing matrix includes a plurality of rows of pile structures, wherein each row is arranged at intervals of at least two pile structures, and adjacent rows of the pile structures are staggered with each other along the length direction of the vertical slot fishway (23).

[0026] Preferably, the vertical slot guide angle is 45°.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present application describes a method for testing a local cross-section model of a fishway, which finds out-of-standard parameters by conducting a cross-section model test of the fishway, and then adjusts them to form a recommended pool structure plan, thereby providing a theoretical experimental basis for making the pool located upstream of the eel way on the vertical slot fishway meet the migratory requirements of eels and Hepu mitten crabs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the pile structure layout in the eel channel of this application. Figure 1 a The pile structure is a convex platform. Figure 1 b: The pile structure is a pipe.

[0030] Figure 2 Schematic diagram of the optimized fishway layout for this application.

[0031] Figure 3 This is a schematic diagram of the vertical seam pool chamber structure of this application.

[0032] Figure 4This is a schematic elevation diagram of the Eel Road for this application.

[0033] Figure 5 For this application, the Eel Road floor plan.

[0034] Figure 6 Schematic diagram of the location of the eel way and vertical slot fishway for this application.

[0035] Figure 7 This is a schematic diagram of the local model scope of this application.

[0036] Figure 8 This is a schematic diagram of the water level distribution along the pool chamber of this application.

[0037] Fig. 9 This is a schematic diagram of the vertical distribution of flow velocity in the vertical seam of this application. Fig. 9 a is a schematic diagram of vertical measuring point distribution. Fig. 9 b is a schematic diagram of the vertical distribution of flow velocity.

[0038] Fig.10 This is a schematic diagram of the distribution of flow velocity measurement points in the pool room for this application.

[0039] Fig.11 This is a schematic diagram of the flow pattern in the pool chamber of the preliminary design scheme of the fishway structure of this application, in which: Fig.11 a is a schematic diagram of the actual flow pattern in the pool chamber of the preliminary design of the fishway structure in this application. Fig.11 b is a vector diagram of the flow pattern and flow field in the pool chamber of the preliminary design scheme of the fishway structure of this application.

[0040] Fig.12 This is a schematic diagram of the flow velocity distribution along different measuring lines in this application (Vx and Vy are vectors, ∑V is a scalar, and θ is the angle with the positive x-axis).

[0041] Fig.13 This is a schematic diagram of the plan structure of the pool chamber in the recommended pool chamber structure for this application.

[0042] Fig.14 Schematic diagram of vertical distribution of flow velocity in the vertical slit of a single-sided vertical slit fishway at different diversion angles in this application.

[0043] Fig.15 Schematic diagram of vertical distribution of flow velocity in vertical slits of different fishway schemes in this application.

[0044] Fig.16 Schematic diagram of typical pool flow fields for different fishway schemes in this application.

[0045] Fig.17 The distribution of mainstream flow velocity along the fishway chamber for different fishway schemes in this application.

[0046] Fig.18 This is the schematic diagram of the pool room layout recommended for this application, where: Fig.18a is the schematic diagram of the pool room layout recommended for this application. Fig.18 b is a schematic diagram of the three-dimensional layout of the pool room recommended for this application.

[0047] Fig.19 This is a schematic diagram of the water level distribution along the pool chamber recommended for this application.

[0048] Fig. 20 This is a schematic diagram of the vertical distribution of flow velocity in the vertical seam of the recommended solution for this application.

[0049] Fig.21 This is the schematic diagram of the flow field distribution in the pool chamber recommended for this application, where: Fig.21 a is a schematic diagram of the flow field distribution in the pool chamber recommended for this application. Fig.21 b is a schematic diagram of the flow field vector in the pool chamber recommended for this application.

[0050] Fig. 22 The flow velocity distribution along the different measuring lines of the recommended solution for this application (Vx and Vy are vectors, ∑V is a scalar, and θ is the angle with the positive x-axis).

[0051] Fig.23 This is a schematic diagram of the overall model layout of the fishway in this application.

[0052] Fig.24 This is a schematic diagram of the planar structural dimensions of the pool chamber for this application.

[0053] Fig.25 This is the vertical slot fishway layout diagram for this application (final optimization plan 1).

[0054] Fig.26 This is the vertical slot fishway layout diagram for this application (final optimization plan 2). DETAILED DESCRIPTION

[0055] The present invention is further described in detail below in conjunction with specific embodiments. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0056] In the description of the specific embodiments of the present invention, unless otherwise specified, the terms indicating the orientation or positional relationship such as "up", "down", "left", "right", "center", "inside", "outside", etc. are all expressions based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship of the invented product / equipment / device when it is usually used. These terms of orientation or positional relationship are only for the convenience of describing the scheme of the present invention or simplifying the description in the specific embodiments, so that the technicians can quickly understand the scheme, rather than indicating or implying that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship, and therefore cannot be understood as a limitation of the present invention. In addition, if the terms "horizontal", "vertical", "overhanging", "parallel" and the like appear, it does not mean that the corresponding device / component / element is absolutely horizontal or vertical or overhanging or parallel, but can be slightly tilted or have deviations. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted. Alternatively, it can be simplified to understand that the corresponding device / component / element is set in the direction of "horizontal", "vertical", "overhanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its role in the scheme of the present invention. In addition, the expressions "first", "second", "third", etc. in the terms are only used to distinguish the description of the same or similar parts, and should not be understood as emphasizing or implying the relative importance of specific parts. In addition, in the description of the embodiments of the present invention, "several", "multiple", "several" represent at least 2. It can be any situation of 2, 3, 4, 5, 6, 7, 8, 9, etc., and can even be more than 9. In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threading, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0057] Example 1

[0058] like Figure 1-Figure 26 As shown, a fishway local section model test method described in this embodiment includes the following steps:

[0059] 1. Formulate a preliminary design plan for vertical slot fishways: Establish a fishway database for hubs. The existing fishway plans in the fishway database for hubs include the left and right bank double fishway plan, the left bank double fishway plan and the right bank double fishway plan.

[0060] The preliminary design is a left bank double fishway scheme: both the vertical slot fishway 23 and the eel way 24 are arranged on the left bank, close to the shore side of the tailwater of the power station 27. The eel way 24 meets the vertical slot fishway 23 near the downstream observation room 34, and then merges into the vertical slot fishway 23. The entrance of fishway 2 should be arranged near the mainstream, at the downstream end of the physical obstacle or flow velocity obstacle that fish can go upstream to. If the eel way 24 is arranged on the right bank of the sluice, the opening probability of its adjacent gate holes is not high and the effect is limited. The left bank double fishway scheme arranges both the eel way 24 and the vertical slot fishway 23 on the tailwater side of the power station 27, which is the mainstream edge of the physical obstacle [sluice] under most working conditions, meeting the conditions of attracting and bringing in fish. In summary, the left bank double fishway scheme is selected as the overall preliminary design of fishway 2.

[0061] Design water level of vertical slot fishway 23: the design water storage level of hub 1 is 8.7m, the dead water level is 8.0m, and the water level fluctuation is 0.7m. Therefore, the design water level of vertical slot fishway outlet 25 is 8.0~8.7m, and the water level fluctuation is 0.7m. The downstream of hub 1 is a tidal river section. The design high water level of the fishway inlet is the average high tide level of 1.84m at the estuary, and the design low water level of vertical slot fishway inlet 26 is the average low tide level of -0.52m at the estuary, and the water level fluctuation is 2.36m. The elevation of the designed inlet bottom plate is lower than the low tide level of -1.31m with a cumulative frequency of 90% of the low tide under the gate, which can ensure that no waterfall is formed at the vertical slot fishway inlet 26.

[0062] like Figure 2 As shown in the figure, the layout principle of the vertical slot fishway inlet 26 is as follows: a. The fish inlet should be arranged at the upstream where fish can go upstream due to the steady and straight water flow, such as the sluice gate, the tailwater of the power station 27, and the ecological water outlet, or near the fish migration route and the place where fish often gather. b. The fish inlet should avoid strong vortexes, backflows, dead water areas and siltation areas. c. The angle between the axis of the fish inlet and the riverbed water flow should not be greater than 45°. According to the above design principles, the vertical slot fishway inlet 26 is arranged on the left bank side of the downstream slope of the tailwater. The angle between the axis of the fish inlet and the riverbed water flow is 45°, and the inlet width is consistent with the fishway width, which is set to 3m. The design low water level is the average low tide level of the estuary -0.52m, the design high water level is the average high tide level of the estuary 1.84m, and the water level difference is 2.36m. The cumulative frequency of low tide below the gate is 90% and the low tide level is -1.31m. Design an inlet with an inlet bottom plate elevation of -1.52m and a wall height of 6m. Ensure that 90% of low tides do not cause waterfalls and that the water is not submerged at high tides. The operating water depth ranges from 1m to 3.36m.

[0063] like Figure 2As shown in the figure, the layout principle of the vertical slot fishway outlet 25 is as follows: a. The fish outlet should be arranged in an area with smooth external water flow and no circulation, so as to facilitate guiding fish upstream; b. The fish outlet should be set in combination with operation management, avoiding floating object gathering areas, docks, swimming, cruise ships and other areas, and should be far away from various water inlets (intakes) and the entrances of navigation buildings; c. The angle between the fish outlet axis and the riverbed water flow should not be greater than 45°; d. The fish outlet should be open. Therefore, the fishway outlet is arranged on the left bank about 150m upstream of the dam. The angle between the outlet axis and the riverbed water flow is set to 30°. The total operating water level of the outlet is 8.0-8.7m, with one outlet and the outlet bottom plate elevation of 7m. The outlet is equipped with a gate, and the gate elevation is set above the flood level to prevent it from being damaged during floods.

[0064] like Figure 3 As shown, the structural parameters of the vertical slit fishway 23 are as follows: Width of the pool chamber 30: The width of the pool chamber 30 should be greater than 2 times the body length of the fish object. When there are multiple types of main fish objects, it should be determined according to the size of the largest fish object. Preferably, the specifications of the main fish objects are 4 to 60 cm, and the width of the fishway is selected to be 3 m, which can meet the requirements of fish passing and is relatively economical. Length of the pool chamber 30: The net length of the pool chamber 30 can be 1.2 to 1.5 times the width of the trough body. Preferably, the length of the pool chamber 30 is 3.6 m. Depth of the pool chamber 30: The water depth of the pool chamber 30 should meet the requirements of the body height of the fish object and the energy dissipation of the pool chamber 30. The minimum water depth should be greater than 2.0 times the body height of the largest fish object, and not less than 1.0 m. Preferably, the design water depth h is 1.0 to 3.36 m. Width of the vertical slit 31 of the fishway: The width of the vertical slit 31 of the partition 32 should not be less than 1 / 3 of the body length of the fish object. A vertical slit 31 type partition 32 is selected. Preferably, the width B of the vertical slit 31 is 0.45 m. The calculation model of the structural parameters of the vertical slit fishway 23 is as follows: I=Δh / (l y +d); n = H / Δh-1; L = n (l y +d)+m(Δl+d); Q=Bhv. h is the allowable water level difference of the partition 32; v is the design flow velocity of the fishway; g is the acceleration of gravity; is the velocity coefficient of the partition 32, which is determined through hydraulic model tests and comprehensive analysis; I is the slope of the bottom slope of the fishway; h is the water level difference of the partition 32; ly is the net length of the pool 30; d is the thickness of the partition 32; n is the number of pools 30; H is the elevation difference of the bottom plate of the vertical slot fishway inlet and outlet; m is the number of rest pools 36; that is, m=k1n, k1 is the quantity ratio coefficient; l=k2l y , k2 is the net length ratio coefficient; L is the total length of the fishway; l is the net length of the rest pool 36; Q is the flow rate of the fishway, B is the width of the vertical slit 31; h is the water depth, and we can get

[0065]

[0066] A preferred method: v is 1.0m / s; it can be 0.85-1.00, or determined through hydraulic model test and comprehensive analysis. Because the pile structure 22 is set at the bottom, it is 0.85. The water head difference of the partition 32 calculated in this way is about 0.0706m; the water level difference of the partition 32 is 0.0706m, the thickness of the pool chamber 30+partition 32 is 3.6, and the bottom slope I=0.0196=1:51.02; H is 8.52m; h=0.0706m. n=120, a rest pool 36 is set every 15-30 pool chambers 30, and k1 is 1 / 15-1 / 30. The rest pool 36 should be flat-bottomed, and the length of the rest pool 36 should not be less than twice the length of the pool chamber 30, and k2≥2. When the rest pool 36 is arranged at a turning point, the length should be appropriately lengthened. There are three rest pools 36 in the fishway at the hub, each of which is 6.6m long. L is the total length of the fishway; m is 3; l is 6.4; after calculation: L = 452m. Q is the flow rate of the fishway, which is 0.45-1.5m 3 / s.

[0067] Fishway bottom plate structure: Eels can swim upstream through the dam through the vertical slit fishway 23. According to the preliminary design of the fishway structure, the eelway 24 and the vertical slit fishway 23 meet near the observation room 34, and then merge into the vertical slit fishway 23 to form a merged section. Therefore, the part of the vertical slit fishway 23 located in the merged section needs to have the function of providing a migratory channel for eels. In order to adapt to the climbing habits of eels, a pile structure 22 is set at the bottom of the vertical slit fishway 23. The pile structure 22 is set to be cylindrical, with a diameter of 15 cm and a height of 10 cm. The center line distance between the two cylindrical piles is 45 cm, and the two rows are staggered. The pile structure 22 can be in the form of inlaid PVC pipes.

[0068] Inlet water replenishment: During the operation of the fishway, the upstream water level may be low and the downstream water level may be high. In extreme cases, the downstream inlet may have a very small flow rate due to the high water level, or even less than the induced flow rate of the fish. In this case, the inlet needs to be replenished. When the water depth at the inlet and outlet of the fishway at Hub 1 is the same, the flow rate of the vertical seam 31 is 1m / s. However, under specific conditions, that is, the water depth at the fishway outlet is 1m and the inlet water depth is 3.36m, the flow rate at the inlet is about 0.04m / s, and the flow rate at the first vertical seam 31 after the inlet is 0.30m / s. Therefore, water replenishment is mainly carried out at the inlet. After water replenishment, the inlet flow rate should be greater than 0.2m / s, and the corresponding water replenishment flow rate is 1.5m 3 / s, at this time the fishway flow rate is 0.45m 3 / s. The water replenishment flow rate during the specific operation process is adjusted according to the actual inlet flow rate monitoring to ensure that the inlet flow rate is greater than 0.2m / s. Therefore, the maximum flow rate of the fishway + water replenishment operation is 1.95m 3 / s. The inlet water supply adopts side wall dispersed water supply, and the outlet is intercepted by mesh to prevent fish from mistakenly entering the water supply pipe.

[0069] Table 4 Fishway parameters

[0070] project parameter project parameter project parameter project parameter Fish pass type Vertical slot fishway Pool room 30 length 3.6m Fishway slope 1：51.02 Rest pool 36 quantity 4 Fishway flow control 1.0m / s Pool room 30 width 3m Import quantity 1 Rest pool 36 length 6.6m Fishway operation flow <![CDATA[0.45-1.5m 3 / s]]> Vertical seam 31 width 0.45m Import elevation -1.52m Export quantity 1 Fishway + water replenishment flow <![CDATA[0.45-1.95m 3 / s]]> Pool Room 30 quantity 120 Fishway Chief 458m Exit elevation 7m

[0071] Design of Eel Passage 24: The bottom plate elevation of the vertical slot fishway inlet 26 is -1.52m, but the riverbed below the lock is excavated to an elevation of -7.5m. In this regard, the vertical slot fishway inlet 26 is mainly located in the surface waters. In order to fully attract fish from all water layers, especially climbing fish, it is very necessary to set up an eel passage 24. The eel passage 24 in the fishway database at the hub usually includes an inclined channel with an inclination of preferably 5°-45° and a base for easy climbing.

[0072] like Figure 4 As shown, the inlet of the eel channel 24 is set as a vertical pipe, installed at the intersection of the vertical retaining wall on the left bank and the downstream bank, and facing the bank, with 7 vertical openings climbing along the bank, as 7 eel inlets 33. Starting from the riverbed bottom plate at -7.5m, an eel inlet 33 is set every 1m. Figure 5 and Figure 6 As shown, the main channel is an aluminum water tank with a length of 13m, a width of 0.27m, and a height of 0.1m, and a water tank slope of 15°. The water tank is covered with a lid to provide a dark environment for migrating eels. A plastic climbing matrix 20 is placed in the water tank, which is composed of staggered plastic pipes. The water tank pipes are immersed in a water flow greater than 3cm deep, which can keep the eels moist and encourage them to climb the steep slope. The eel way 24 merges into the vertical slit fishway 23 at the third rest pool 36 downstream, and then the eels will continue to swim upstream using the vertical slit fishway 23. Observation room 34: The fishway 2 is provided with an observation room 34, which is located on the upstream side of the intersection of the vertical slit fishway 23 and the eel way 24, to count the species and number of fish that have successfully gone upstream, and evaluate the fish passage effect of the fishway, so as to improve the structure of the fishway in the future and improve the fish passage effect.

[0073] In summary: a. According to the water dispatching plan for the fishway at hub 1, considering that the operation of power station 27 has more constant water flow than the sluice and is less likely to produce a backflow zone induced by the sluice dispatching, the vertical slot fishway 23 and the eel way 24 are arranged on the left bank, close to the shore side of the tailwater of power station 27. The eel way 24 meets the vertical slot fishway 23 near the downstream observation room 34, and then merges into the vertical slot fishway 23. b. The bottom slope of the vertical slot fishway 23 is 1:51.02, the total length is 458m, and there is 1 inlet with a bottom elevation of -1.52m and 1 outlet with a bottom elevation of 7m. The fishway comprises 30120 pool chambers and 364 rest pools. The cross section of the pool chamber 30 is a rectangular cross section, the bottom slope of the pool chamber 30 is I=1.96%, the thickness of the partition 32 and the guide plate 35 are both 30 cm, the diversion angle is 30°, no pier heads are set at the ends of the partition 32 and the guide plate 35, and the ends are rounded with a radius R=15 cm; the net width of the pool chamber 30 is 3.0 m, the length of the pool chamber 30 is 3.6 m, the designed water depth h is 1.0~3.36 m, the designed vertical seam 31 is 45 cm wide, and a pile structure 22 with a diameter of 15 cm and a height of 10 cm is set at the bottom. The center line spacing of the piles is 45 cm, and they are arranged in two rows in a staggered manner. c. At the intersection of the vertical retaining wall on the left bank and the downstream bank, a vertical eel channel 24 entrance is set toward the bank. Starting from the riverbed bottom plate at -7.5m, an entrance is set every 1m, with a total of 7 eel entrances 33; the main channel is an aluminum water trough with a length of 13m, a width of 0.37m and a height of 0.1m. The slope of the water trough is 15°. The water trough is covered with a cover. A plastic climbing matrix 20 is placed in the water trough. The matrix is ​​composed of staggered plastic pipes. The water trough pipes can be immersed in a water flow greater than 3cm deep; the eel channel 24 merges into the vertical slit fish channel 23 at an elevation of 3.39m, and then the eels will use the vertical slit fish channel 23 to continue to swim upstream.

[0074] Fishway partial section model test

[0075] Research content: The main research contents of the partial section model test of the fishway are: a. Research on the internal structure and flow pattern of the pool chamber 30; b. Observe the water level difference between the upstream and downstream sections of the adjacent pool chambers 30, the flow velocity, flow pattern and local water flow phenomenon through the fish gap; c. Measure the flow velocity distribution, flow pattern and local water flow phenomenon in the pool chamber 30; d. Research and determine the form of the energy dissipation structure (such as the partition 32), the size of the pool chamber 30 and the vertical gap 31, etc. Finally, a recommended plan for the structure of the pool chamber 30 is formed.

[0076] Preparation of the local section physical model of the fishway project: Similarity conditions: According to the research content of the local section physical model of the fishway project, the local section physical model of the fishway project should be a normal model, and the model design is carried out according to the gravity similarity criterion, and the model is a normal model. Taking into account the scale of the fishway structure and the limitations of the model site, the geometric scale of the local section physical model of the fishway project is determined to be 1:4. The model should meet the geometric similarity, water flow movement similarity and dynamic similarity, and follow the Froude similarity criterion. The scales of each item are shown in Table 5.

[0077] Table 5 Calculation table of various scales of the local section physical model of the fishway project

[0078] Scale Plane scale Vertical scale Flow rate scale Flow rate scale Roughness scale formula <![CDATA[λ L ]]> <![CDATA[λ H ]]> <![CDATA[λ v =λ L 1 / 2 ]]> <![CDATA[λ Q =λ L 5 / 2 ]]> <![CDATA[λ n =λ L 1 / 6 ]]> Actual scale 4 4 2 32 1.26

[0079] In addition, the model water flow must be turbulent, that is, the model Reynolds number Rem = VR / v = 46875> 1000. In the formula, V is the water flow velocity, m / s; R is the hydraulic radius, m; ν is the water flow motion viscosity coefficient.

[0080] The scope of the local section model: The local section physical model of the fishway project is based on the preliminary design of the vertical slot fishway 23. In combination with the requirements and contents of the test research, the scope of the local model includes 10 pools 30 in the fishway, marked C1~C10, 11 groups of baffles 32, marked 1#~11# baffles 32, and guide plates 35. The upstream is connected to the flat channel, and the downstream is connected to the adjustable tail gate. The local model structure layout is shown in Figure 7 , which includes an upstream flat bottom section, a test slope section and a downstream flat bottom section which are connected in sequence.

[0081] Model making: During the process, the bottom slope of the fishway is controlled by the cross-section method and cast with cement; the partition 32 and the guide plate 35 are made of gray plastic board and wood board; the pile structure 22 is made of PVC pipe. In order to facilitate the observation of the flow state and fish migration characteristics in the pool chamber 30, the single side wall of the model pool chamber 30 is made of plexiglass as the observation section of the pool chamber 30. The roughness should meet the resistance similarity requirements. According to the design scheme of the vertical seam fishway 23, the design bottom slope of the pool chamber 30 is I=1.96%, the net width of the prototype pool chamber 30 is 3.0m, the length of the pool chamber 30 is 3.6m, the width of the partition 32 and the guide plate 35 are both 0.3m, and the end is rounded with a radius of R=0.15m, the width of the vertical seam 31 is 0.45m, the diversion angle is 30°, and the bottom pile structure 22 has a diameter of 0.15m and a height of 0.10m.

[0082] Experimental study on design scheme: According to the preliminary design scheme of vertical slot fishway 23, the bottom slope of chamber 30 is designed to be I=1.96%, corresponding to the low water level design conditions upstream and downstream of the fishway, the average low tide level at the estuary is -0.52m ~ the outlet operating water level is 8.0m, and the minimum water depth in chamber 30 is 1m. On the basis of the unchanged geometric scale of chamber 30, the volume of energy dissipation water body is the minimum value, which is used as the most unfavorable design condition to carry out the local section model test of the fishway. During the test, the upstream flat water channel and the downstream overflow plate were used to control the upstream and downstream water levels to be constant. 12 water gauges were arranged along the model to measure the water level of chamber 30, and the flow field of chamber 30 and vertical slot 31 was collected at a single point using an acoustic Doppler flow meter. Figure 8As shown, the water level difference of chamber 30: the water depth of the inlet and outlet is controlled to be 1m, and the water level distribution of chamber 30 along the way is measured by a water gauge to consider the influence of the inlet and outlet water flow stability. The water level characteristic values ​​of the typical chamber 30 in the middle of the model are shown in Table 6.

[0083] Table 6 Water level characteristic values

[0084] serial number C4 C5 C6 C7 C8 Pool room 30 water level (m) 1.44 1.38 1.31 1.25 1.18 Water level difference between 30 pool rooms / 0.06 0.07 0.06 0.07 Water depth in the pool room 30m 0.98 0.99 0.99 1 1

[0085] It can be seen from the above table that the water surface line of chamber 30 is basically parallel to the bottom slope, the average water depth of typical chambers 30C4~C8 is 0.99m on average for each chamber 30 in the local model, and the average water level difference of each level of chambers 30 is 0.065m.

[0086] Flow velocity distribution of vertical slit 31: Flow velocity of 5#~7# vertical slit 31 was measured. Four measuring points at different positions were arranged from top to bottom along the water depth on the center line of each vertical slit 31 [0.8H, 0.6H, 0.4H, 0.2H, 0.12H, H is the water depth value of vertical slit 31]. The flow velocity of the measuring points of the vertical slit 31 passing the fish is summarized in Table 7. The flow velocity distribution of vertical slit 31 is as follows Fig. 9 .

[0087] Table 7 Flow velocity at each measuring point vertically through the fish vertical slit 31, m / s;

[0088]

[0089] By testing the swimming ability of the target fish species, it was found that the flow velocity distribution of the vertical slot 31 in the vertical slot fishway 23 was 0.54-1.37 m / s, and the average flow velocity was 1.0 m / s.

[0090] It can be seen from the above table that the average flow velocity of the vertical seam 31 under the design scheme is 1.11m / s, and the flow velocity range of the measuring point is between 0.78 and 1.36m / s, which basically meets the value range requirement of 0.54 to 1.37m / s. The average flow velocity exceeds the average flow velocity control index of 1m / s.

[0091] Calculate the velocity coefficient of the partition 32 according to the following formula And the power dissipation E of 30 units of water in the pool room: E = ρg△hQ / V, v is the average flow velocity of the vertical seam 31; △h is the average water level difference of the partition 32; Q is the average flow rate of the fishway; V is the water volume of the pool chamber 30 (m 3 ) According to calculation, the flow rate of vertical slot fishway 23 is Q = 0.50m 3 / s, velocity coefficient of partition 32 , meeting the requirements; unit water power dissipation E = 29.43W / m 3 <200W / m 3, that is, the turbulence intensity of the water flow in the pool chamber 30 is small enough, and the size of the pool chamber 30 meets the power dissipation requirements per unit water body.

[0092] Flow field distribution in the pool chamber 30: Taking the C6 pool chamber 30 as an example, the C6 pool chamber 30 is selected to measure the surface flow field distribution. Five measuring lines marked N1 to N5 are set along the width of the pool chamber 30. Each measuring line has 7 measuring points marked L1 to L7 along the length of the pool chamber 30, totaling 35. The measuring points are distributed as follows: Fig.10 .

[0093] like Fig.11 As shown, from the schematic diagram of the flow field distribution of the pool chamber 30 in the design scheme, it can be seen that, driven by the water level difference between the upstream and downstream of the vertical slit 31, the water flows around the baffle 32 and passes through the vertical slit 31, and enters the pool chamber 30 in the form of a jet to form the mainstream of the pool chamber 30. The mainstream of the pool chamber 30 is continuous and smooth, that is, the degree of curvature is small. A rear circulation is formed behind the baffle 32, and a complete recirculation zone is not formed behind the guide plate 35. The flow velocity of the measuring point in the pool chamber 30 is shown in Table 8. The flow velocity distribution along the width of the pool chamber 30 on each measuring line [N1~N5] is shown in the figure. Fig.12 .

[0094] Table 8 Measurement points and flow velocity ∑V (m / s) in chamber 30

[0095]

[0096] like Fig.12 As shown in the figure, it can be seen from the distribution of Vx along the path that the near-side wall measurement lines N1 and N5 are negative in the front section of the pool chamber 30, corresponding to the backflow behind the partition 32 and the guide plate 35. The negative value range of Vx of the N1 measurement line (0.79≤x≤3.04m) and the value are larger than those of the N5 measurement line (-0.22≤Vx≤-0.02m / s), that is, the backflow behind the partition 32 has a larger impact range and intensity; from the distribution of ∑V along the path in the figure, it can be seen that the mainstream in the pool chamber 30 is not fully diffused, the flow velocity is unevenly distributed along the cross-sectional width, and the maximum flow velocity is concentrated at the positions of the two measurement lines N3 and N4, and the minimum value of the mainstream ∑V=0.81m / s. The ratio of the minimum value of the mainstream of the pool chamber 30 to the average flow velocity of the vertical seam 31 reflects the energy dissipation rate of the pool chamber 30. The energy dissipation rate of the pool chamber 30 in the design scheme is about 27%.

[0097] The near-wall area provides a low velocity area to ensure that the target fish can rest, but in order to prevent small fish from getting lost and delaying their upstreaming time, a certain amount of backflow is required to meet the energy dissipation requirements, but the backflow cannot be too intense and the range cannot be too large. Definition L c is the maximum length of the recirculation zone, B c is the maximum width of the reflow zone, v cmax is the maximum flow velocity in the recirculation zone, L is the length of the pool chamber 30, B is the width of the pool chamber 30, and the quantitative parameters of the recirculation zone are shown in Table 9.

[0098] Table 9 Reflow zone parameters

[0099] Recirculation zone location <![CDATA[L c / L]]> <![CDATA[B c / B]]> <![CDATA[L c / B c ]]> <![CDATA[L c B c / LB]]> <![CDATA[v cmax (m / s)]]> After partition 32 0.83 0.50 2.00 0.42 0.34 Guide plate 35 rear / / / / /

[0100] L c B c / LB can be used to define the impact range of the reflow zone, from Fig.11 As can be seen from Table 9, the recirculation area behind the guide plate 35 is suppressed under the design scheme, and a stable and complete recirculation is not formed. The recirculation area behind the partition plate 32 has a large influence range, and L c B c / LB=0.42,intensity v cmax =0.34m / s.

[0101] In summary: the preliminary design of the vertical slot fishway 23, the section of the pool chamber 30 is a rectangular section, the bottom slope of the pool chamber 30 is I = 1.96%, the length of the pool chamber 30 is 3.6m, the thickness of the partition 32 and the guide plate 35 are both 0.3m, the net width of the pool chamber 30 is 3.0m, the ends of the partition 32 and the guide plate 35 are not provided with piers, and are rounded by a semicircular arc with a radius of 0.15m, the width of the fish vertical slot 31 is 0.45m, the diversion angle is 30°, and the bottom is provided with a pile structure 22 with a diameter of 15cm and a height of 10cm, the centerline spacing of the piles is 45cm, and the two rows are staggered. By establishing a local model with a geometric scale of 1:4 to demonstrate the water flow conditions of the design scheme, the following conclusions are obtained:

[0102] The water surface line along the pool chamber 30 is basically parallel to the bottom slope, the average water level difference of the pool chamber 30 is 0.065m, the average flow velocity of the vertical seam 31 is 1.11m / s, and the flow velocity at the measuring points is distributed between 0.97 and 1.36m / s, which basically meets the value range requirement of 0.54 to 1.37m / s. The average flow velocity exceeds the average flow velocity control index of 1m / s.

[0103] The flow rate of vertical slot fishway 23 is about 0.50m 3 / s, velocity coefficient of partition 32 Unit water power dissipation E = 29.43 W / m 3 The turbulence intensity of the water flow in the pool chamber 30 is small, and the size of the pool chamber 30 is reasonable to meet the power dissipation requirements of the unit water body.

[0104] Driven by the water level difference between chambers 30, the water flow bypasses the pier of partition 32 and enters chamber 30 through the fish-passing vertical slit 31. The mainstream in chamber 30 has a small curvature along the way and is not sufficiently diffused along the width of chamber 30. The maximum flow velocity is concentrated on the N3 and N4 measuring lines along the way, and the minimum value of the mainstream is 0.81 m / s. The average flow velocity in chamber 30 is 0.50 m / s, which meets the recommended average flow velocity range of 0.24 to 0.67 m / s for chamber 30.

[0105] There is no obvious deflection and diffusion of the mainstream in the pool chamber 30. The development of the backflow behind the guide plate 35 is suppressed, and a complete and stable backflow zone is not formed. A large-scale backflow zone is formed behind the partition 32 under the shear effect of the mainstream. cBc / LB=0.42, maximum reflux intensity v cmax =0.34m / s. A large reflux range can easily cause small fish to lose their way.

[0106] In summary, under the design scheme, the scale of the pool chamber 30, the width of the vertical seam 31, and the main bottom slope are basically reasonable and meet the upstream requirements of the target fish; the diversion angle is small, so that the mainstream injected into the pool chamber 30 through the vertical seam 31 does not undergo obvious deflection and energy dissipation in the pool chamber 30, which is about 27%. The average flow velocity in the vertical seam 31 exceeds the design recommended value. At the same time, a large-scale reflux area is formed on the rear side of the partition 32, which can easily cause small fish to lose their way and delay the upstream time. It is necessary to adjust the flow state in the pool chamber 30.

[0107] Experimental study on optimization scheme

[0108] Overview of the optimization scheme: After the design scheme test, the diversion angle of 30° is too small, which is the main reason why the mainstream is almost vertically injected into the lower chamber 30 and the diffusion is insufficient in the chamber 30, and the influence range of the single-sided recirculation area behind the partition 32 is too large. Therefore, the optimization idea of ​​increasing the diversion angle to promote the deflection of the mainstream in the chamber 30 is adopted. The diversion angle is optimized, and the scale of the chamber 30, the width of the vertical seam 31, the bottom slope of the chamber 30 and the arrangement of the pile structure 22 remain unchanged, and a series of optimization test studies are carried out. Based on the design scheme of 30° diversion angle, it is increased to 45° and 50° respectively to form 45° and 50° single-sided vertical seam fishway 23 schemes, and a 45° opposite-side vertical seam fishway 23 scheme is added for synchronous comparative demonstration. The characteristic structural parameters of the optimization scheme and the structure of the chamber 30 are shown in Table 10, Fig.13 .

[0109] Table 10 Characteristic structural parameters of the series of optimization schemes and vertical seam flow rates of different schemes

[0110]

[0111] Comparative analysis of schemes: Same-side vertical slot fishway scheme: In view of the unfavorable water flow conditions in the pool chamber 30, such as the average flow velocity of the vertical slot 31 exceeding the design requirements and no obvious deflection of the mainstream in the pool chamber 30, a comparative analysis was conducted on the three sets of design schemes of the single-side vertical slot fishway 23, Run1 and Run2.

[0112] The flow rates of the vertical slot 31 of the three groups of vertical slot fishway 23 on the same side are shown in Table 10. Fig.14. Compared with the design scheme, the water flow velocity in the vertical seam 31 decreases after the diversion angle increases. Among them, the average flow velocity of the vertical seam 31 in Run1 decreases more significantly, that is, when the diversion angle is adjusted to 45°, the average flow velocity of the vertical seam 31 drops from 1.11m / s in the design scheme to 1.01m / s, and the flow velocity range is 0.99~1.06m / s, which meets the design recommended flow velocity requirements. When the diversion angle continues to increase to 50°, the flow velocity of the vertical seam 31 in the Run2 scheme increases compared with the Run1 scheme. The average flow velocity of the vertical seam 31 is 1.05m / s, and the flow velocity is distributed in the range of 1~1.16m / s. At the same time, it can be seen from the vertical distribution of the flow velocity that the vertical distribution of the flow velocity in the vertical seam 31 is more uniform after the diversion angle increases.

[0113] Different-side vertical slit fishway 23 scheme: By comparing the three groups of single-side vertical slit fishway 23 schemes with different diversion angles, it can be seen that when the diversion angle is 45°, the flow velocity in the vertical slit 31 decays most significantly, and the average flow velocity is 1.01m / s, which meets the flow velocity recommendations proposed in the design stage. Therefore, based on this diversion angle, in view of the design problems exposed by the design scheme, such as insufficient mainstream deflection and the flow state in the pool chamber 30 being unfavorable for fish to swim upstream, the water flow conditions of the three groups of schemes are compared: the design scheme, the single-side vertical slit fishway 23Run1 with a diversion angle of 45°, and the double-side vertical slit fishway 23Run3 with a diversion angle of 45°. The flow velocity distribution of the vertical slit 31 of different schemes is shown in Table 11, Fig.15 The typical flow field distribution under the three schemes is as follows: Fig.16 .

[0114] As can be seen from the chart, for the same diversion angle, the arrangement of the vertical seams 31 on the opposite sides has an adverse effect on the water flow energy dissipation. Under the Run3 scheme, the average flow velocity of the vertical seams 31 reaches 1.23m / s, which is 23% higher than the average flow velocity of 1.0m / s recommended by the design. Fig.16 It can be seen that the mainstream in the pool chamber 30 of both Run1 and Run3 schemes is significantly deflected, such as Fig.17 As shown, compared with the design scheme, the mainstream in the pool chamber 30 attenuates significantly along the way, and the attenuation rate increases to about 50%. The single-sided vertical slit 31 scheme of Run1 forms a slightly curved S-shaped mainstream in the single-stage pool chamber 30, and forms a complete recirculation zone behind the baffle 32 and the recirculation zone behind the guide plate 35 on both sides of the mainstream. The mainstream in the pool chamber 30 shows a trend of first decreasing and then increasing, with a minimum value of 0.51m / s in the middle and lower section of the pool chamber 30 (L6 survey line); the opposite-side vertical slit 31 scheme (Run3) forms an S-shaped mainstream in two consecutive pool chambers 30, and a recirculation zone behind the baffle 32 is formed in the single-stage pool chamber 30. The mainstream in the pool chamber 30 decreases along the way, and the mainstream minimum value of 0.60m / s appears near the lower vertical slit 31 at the downstream end of the pool chamber 30.

[0115] Table 11 Flow rate of vertical seam 31 in different schemes

[0116]

[0117] Summary of optimization scheme: In view of the water flow conditions that are not conducive to fish upstreaming, such as the average flow velocity of the vertical slit 31 slightly exceeding the design recommended value shown in the design scheme test, insufficient mainstream deflection in the pool chamber 30, and obvious development of unilateral backflow behind the partition 32, the optimization idea is to increase the diversion angle to promote the mainstream deflection of the pool chamber 30. The three groups of optimization schemes of the single-sided vertical slit fishway 23 scheme with diversion angles of 45° and 50° and the opposite-side vertical slit fishway 23 with a diversion angle of 45° are compared and demonstrated simultaneously. Combining the test results of the three groups of vertical slit fishway 23 optimization schemes, it can be seen that with the increase of the diversion angle, the mainstream in the pool chamber 30 is significantly deflected compared with the design scheme (30° diversion angle), and the mainstream attenuation rate in the pool chamber 30 increases from 23% to about 50%. The single-sided vertical slot fishway 23 with a diversion angle of 45°, the flow velocity of the vertical slot 31 and the distribution characteristics of the main stream in the chamber 30 along the way are more reasonable than other schemes. The average flow velocity of the vertical slot 31 is reduced from 1.11m / s in the design scheme to 1.01m / s, which meets the design recommended flow velocity requirements of the vertical slot 31. At the same time, the main stream in the single-stage chamber 30 forms a slightly curved S-shaped curve, and a complete and stable recirculation zone is formed on both sides of the main stream. Therefore, the single-sided vertical slot fishway 23 scheme with a diversion angle of 45°, chamber 30 scale, vertical slot 31 width, chamber 30 bottom slope and pile structure 22 arrangement remaining the same as the design scheme is recommended as the local section model of the fishway at the hub 1.

[0118] Test results of the recommended scheme: Scheme overview: The designed bottom slope of the pool chamber 30 is I = 1.96%, the net width of the prototype pool chamber 30 is 3.0m, the length of the pool chamber 30 is 3.6m, the width of the partition 32 and the guide plate 35 are both 0.3m, and the ends are rounded with a radius of R = 0.15m, the width of the vertical seam 31 is 0.45m, the diversion angle is 45°, the bottom pile structure 22 has a diameter of 0.15m and a height of 0.10m, and the pool chamber 30 is arranged as follows Fig.18 . Water level difference in pool room 30: Fig.19 As shown, the water depth at the inlet and outlet is controlled to be 1m. The water level distribution of 30 chambers along the recommended scheme is measured by water gauge. Considering the influence of the water flow stability at the inlet and outlet, the water level characteristic values ​​of 30 chambers in the middle of the model are shown in Table 5.4-4.

[0119] Table 5.4-4 Water level characteristic values

[0120] serial number C4 C5 C6 C7 C8 Pool room 30 water level (m) 1.47 1.4 1.33 1.26 1.19 Water level difference between 30 pool rooms / 0.07 0.07 0.07 0.07 Water depth in the pool room 30m 1 1 1 1.01 1.01

[0121] It can be seen from the above table that the water surface line of chamber 30 is basically parallel to the bottom slope. The water levels of the upstream inlet and downstream outlet of the control model are 1.71m and 1.00m respectively, that is, the water depth of the flat slope section is maintained at 1.00m. The average water depth of chambers C4 to C8 is 1.00m, and the average water level difference of chambers 30 at each level is 0.07m.

[0122] Flow velocity distribution of vertical seam 31: Flow velocity of 5#~7# vertical seams 31 was measured. Four measuring points were arranged from top to bottom along the water depth on the center line of each vertical seam 31, which were 0.8H, 0.6H, 0.4H, and 0.2H, respectively. H is the water depth value at the vertical seam 31. The flow velocity of the measuring points of the vertical seam 31 passing the fish is summarized in Table 12. The flow velocity distribution of the vertical seam 31 is as follows: Fig. 20 .

[0123] Table 12 Flow velocity at each measuring point in the vertical slit 31 (m / s)

[0124]

[0125] It can be seen from the chart that under the recommended scheme, the average flow velocity of the vertical joint 31 is 1.01m / s, and the average flow velocity of the measuring points is distributed between 0.99 and 1.06m / s, which basically meets the requirements of the average flow velocity of the vertical joint 31 being 1m / s and the flow velocity distribution being in the range of 0.54 to 1.37m / s.

[0126] The recommended solution is vertical slot fishway 23 flow rate Q = 0.45m 3 / s, calculate the velocity coefficient of partition 32 The power dissipation of 30 units of water in the pool is E = 28.61 W / m 3 <200W / m 3 , the size of pool chamber 30 meets the power dissipation requirements per unit water body.

[0127] Flow field distribution in the pool chamber 30: Select a typical pool chamber 30 to measure its flow field distribution, and the measurement point arrangement is the same as the design scheme. The recommended solution pool chamber 30 flow field distribution is shown as follows Fig.21 As can be seen from the figure, driven by the water level difference between the upstream and downstream of the vertical slit 31, the water flows around the baffle 32 and passes through the vertical slit 31 to enter the pool chamber 30 in the form of a jet to form the mainstream of the pool chamber 30. The mainstream presents an obvious S-shaped continuous curve in the pool chamber 30, and a complete and stable recirculation zone is formed behind the baffle 32 and the guide plate 35. The flow velocities of the measuring points in the pool chamber 30 of the recommended solution are shown in Table 13. The minimum flow velocity of the mainstream occurs at the measuring point L6, ∑V=0.51m / s, which is significantly lower than the minimum flow velocity of the mainstream in the design solution, that is, as the curvature of the mainstream entering the pool chamber 30 increases, the degree of mainstream attenuation increases.

[0128] Table 13 Measurement points and flow rate ∑Vm / s in chamber 30

[0129]

[0130] The flow velocity distribution along the 5 measuring lines [N1~N5] with a width of 30 in the pool is as follows Fig. 22As shown. From the distribution of Vx along the figure, it can be seen that the near-side wall measurement lines N1 and N5 are negative in the front section of the pool chamber 30, corresponding to the recirculation area behind the partition 32 and the guide plate 35. The negative value range of Vx of the N1 measurement line is 1.24≤x≤2.14m, and the value is -0.13≤Vx≤-0.01m / s. The negative value range of Vx of the N5 measurement line is 1.24≤x≤3.04m, and the value is -0.22≤Vx≤-0.04m / s; From the distribution of ∑V along the figure, it can be seen that the mainstream in the pool chamber 30 is concentrated at the positions of the two measurement lines N3 and N4, and the flow velocity distribution in the pool chamber 30 is more uniform than the design scheme, that is, the mainstream is effectively dissipated through the vertical slit 31 jet. The quantitative parameters of the recirculation zone of the recommended scheme are shown in Table 14.

[0131] Table 14 Reflow zone parameters

[0132] Recirculation zone location <![CDATA[L c / L]]> <![CDATA[B c / B]]> <![CDATA[L c / B c ]]> <![CDATA[L c B c / LB]]> <![CDATA[v cmax (m / s)]]> After partition 32 0.38 0.33 1.36 0.12 0.18 Guide plate 35 rear 0.5 0.33 1.82 0.17 0.24

[0133] The influence range L of the backflow area behind the partition 32 c B c / LB=0.12, reflux intensity v cmax =0.18m / s, the influence range of the recirculation area behind the guide plate 35 is L c B c / LB=0.17, reflux intensity v cmax =0.24m / s. Compared with the design scheme, the backflow in the pool chamber 30 of the recommended scheme is redistributed to form a stable and complete backflow behind the guide plate 35, and the influence range of the backflow behind the partition 32 is reduced from 0.42 to 0.12, and the intensity is attenuated from 0.34m / s to 0.24m / s.

[0134] Summary of recommended solutions: The diversion angle 30° is too small as exposed in the design solution. The mainstream is almost vertically injected into the lower chamber 30, and the mainstream diffusion in the chamber 30 is insufficient. The unilateral backflow range behind the baffle 32 is too large, which makes it easy for the target fish to swim upstream, creating unfavorable water flow conditions in the chamber 30. The diversion angle is optimized. Hub 1 recommends keeping the scale of the chamber 30, the width of the vertical seam 31 and the bottom slope of the chamber 30 unchanged, increasing the diversion angle to 45°, promoting the mainstream deflection in the chamber 30, increasing the mainstream energy dissipation to form the optimized water flow structure of the chamber 30. The water flow conditions are demonstrated through a local model with a geometric scale of 1:4, and the following conclusions are obtained:

[0135] The water surface line along the pool chamber 30 is basically parallel to the bottom slope, the average water level difference of the pool chamber 30 is 0.07m, the average flow velocity of the vertical seam 31 is 1.01m / s, and the vertical line of the flow velocity is evenly distributed from the top of the pile structure 22 to the free water surface. The flow velocity of the vertical seam 31 is distributed between 0.99 and 1.06m / s, and the flow velocity of the vertical seam 31 passing fish meets the average flow velocity of 1m / s, and the flow velocity distribution ranges from 0.54 to 1.37m / s.

[0136] The flow rate coefficient of vertical seam 31 type baffle 32 is φ = 0.86, and the power dissipation per unit water in chamber 30 is E = 28.61 W / m 3 <200W / m 3 , the size of the pool chamber 30 meets the power dissipation requirements of the unit water body; on the basis of the unchanged size and bottom design of the pool chamber 30, the structure of the vertical seam 31, the partition 32 and the guide plate 35 is optimized, and the flow rate coefficient Reduced, corresponding to the design water depth of 1m, the flow rate of vertical joint 31 is about 0.45m 3 / s, which is about 7% lower than the design solution.

[0137] Under the recommended scheme, the water flow is driven by the water level difference between the chambers 30, bypasses the baffle 32 pier, and enters the chamber 30 through the fish-passing vertical slit 31. The mainstream in the chamber 30 is continuous, clear and S-shaped. After entering the chamber 30, the mainstream is effectively diffused. The average flow velocity in the chamber 30 is 0.37 m / s, which meets the average flow velocity range of 0.24 to 0.67 m / s in the chamber 30, and the mainstream flow velocity is ≥ 0.51 m / s.

[0138] The curvature of the mainstream in the pool chamber 30 increases, and a complete and stable reflux zone with a considerable influence range and strength is formed behind the partition 32 and the guide plate 35. The influence range of the reflux zones on both sides is 0.12-0.17, and the reflux intensity range is 0.18-0.24 m / s. A low flow velocity zone is created near the wall to ensure that the target fish can rest while preventing small fish from getting lost and delaying their upstreaming time.

[0139] The single-side vertical slot fishway 23 at the hub 1 has a rectangular section of the pool 30, a bottom slope of the pool 30 of I = 1.96%, a length of 3.6m, a thickness of 0.3m for the partition 32 and the guide plate 35, a net width of 3.0m, a width of 0.45m for the fish vertical slot 31, and a pile structure 22 with a diameter of 15cm and a height of 10cm at the bottom, a pile centerline spacing of 45cm, and two rows of staggered arrangements. By establishing a local cross-section model of the fishway with a geometric scale of 1:4, the rationality of the structure of the pool 30 and the partition 32 and the water flow conditions are evaluated, and an optimization study is conducted, and the following conclusions are obtained:

[0140] Under the design scheme, the pool chamber 30 scale, vertical seam 31 width, and main bottom slope design are basically reasonable, meeting the target fish's upstream requirements; the fishway flow rate is about 0.50m 3 / s, velocity coefficient of partition 32 The diversion angle is small, so that the mainstream injected into the pool chamber 30 through the vertical slit 31 does not have obvious deflection and energy dissipation in the pool chamber 30. The average flow velocity of the vertical slit 31 is 1.11m / s. After entering the pool chamber 30, the maximum flow velocity is concentrated along the N3 and N4 measuring lines, and the minimum value of the mainstream is 0.81m / s. At the same time, the development of the backflow behind the guide plate 35 is suppressed, and a complete and stable backflow zone is not formed. Under the action of the mainstream shear, a large-scale backflow zone is formed behind the partition 32, L c B c / LB=0.42, which may easily cause small fish to lose their way and delay their upstreaming time. Therefore, the flow pattern in the pool chamber 30 needs to be adjusted.

[0141] The small value of the diversion angle is the main reason why the water flow conditions in the vertical seam 31 and the pool chamber 30 do not meet the requirements of fish upstream; therefore, in order to promote the deflection of the mainstream in the pool chamber 30 and increase the energy dissipation of the mainstream, the diversion angle is adjusted to optimize the water flow structure of the pool chamber 30; the recommended solution is to keep the scale of the pool chamber 30, the width of the vertical seam 31 and the bottom slope of the pool chamber 30 unchanged, and increase the diversion angle to 45°.

[0142] Under the recommended solution, the average water level difference of the pool chamber 30 is 0.07m, the average flow velocity of the vertical seam 31 is 1.01m / s, the flow velocity distribution of the vertical seam 31 is between 0.99 and 1.06m / s, and the flow velocity of the fish-passing vertical seam 31 meets the requirements of an average flow velocity of 1m / s and a flow velocity distribution range of 0.54 to 1.37m / s. On the basis of the unchanged size and bottom design of the pool chamber 30, the flow velocity coefficient is has decreased, For a design water depth of 1m, the flow rate of vertical seam 31 is about 0.45m 3 / s, which is about 7% lower than the design. The mainstream in the pool chamber 30 is continuous, clear and S-shaped. After entering the pool chamber 30, the mainstream is effectively diffused. The average flow velocity in the pool chamber 30 is 0.37m / s, which meets the average flow velocity range of 0.24-0.67m / s in the pool chamber 30, and the mainstream flow velocity is ≥0.51m / s. The curvature of the mainstream in the pool chamber 30 is increased, and a complete and stable recirculation zone with a considerable influence range and strength is formed behind the partition 32 and the guide plate 35. The influence range of the recirculation zones on both sides is 0.12-0.17, and the recirculation strength range is 0.18-0.24m / s. A low flow velocity zone is created near the wall to ensure that the target fish can rest while preventing small fish from getting lost and delaying the upstream time.

[0143] like Fig.23 and Fig.24As shown, the overall model test of the fishway: The overall model test of the fishway mainly carries out the following research on the vertical slot fishway 23: a. Under the typical operating water level conditions upstream and downstream of the fishway, the water flow pattern and the conditions for fish entering and leaving the designed fishway; b. Under different operating water level conditions during the fishing period, the flow rate, water surface along the way, flow velocity changes of the designed fishway, and the flow velocity and flow pattern of the fish pond and rest pool 36; c. Propose suggestions for optimizing the type, scale and plane layout of the fishway inlet and outlet.

[0144] In view of the problems existing in the preliminary design scheme, two optimization schemes were tested based on the two ideas of reducing the flow rate of the fishway body and increasing the water depth of the chamber 30 with excessive flow rate. Optimization scheme 1 takes the measure of reducing the width of the vertical slit 31 of the outlet section, which achieves the purpose of reducing the flow rate of the fishway, so that the flow rate of each chamber 30 and the vertical slit 31 of the most downstream straight section is reduced, but still does not meet the design flow rate requirement. In addition, the reduction in the flow rate of the fishway caused a significant drop in the water level of most of the middle chambers 30. Under working condition 4, the water depth of the chamber 30 does not meet the minimum design water depth requirement of the fishway. Optimization scheme 2 increases the water depth of the chamber 30 and effectively reduces the flow rate of the vertical slit 31 by reducing the 15 chambers 30 [1-15#] and the inlet bottom elevation of the most downstream straight section. The flow rates of the fishway vertical seam 31 and the pool chamber 30 can meet the design requirements under all working conditions. However, the lower the bottom elevation of the fishway inlet and the deeper the water depth, the inlet flow rate is significantly reduced. In working conditions 3 and 6, that is, the highest downstream operating water level working conditions, the inlet flow rate is 0.2m / s lower than the induced flow rate of migratory fish, which does not meet the design requirements. In order to ensure that the mainstream flow rate at the fishway inlet is not lower than the induced flow rate of migratory fish, water is replenished at the fishway inlet. The minimum replenishment flow rates of working conditions 3 and 6 are 0.7m / s and 0.6m / s, respectively. 3 / s, 1.0m 3 / s.

[0145] In summary, by establishing an overall fishway model with a geometric scale of 1:25 and combining the results of local model tests, the layout scheme of the vertical slot fishway 23 in hub 1 was demonstrated and optimized experimentally, and the following conclusions were obtained:

[0146] According to the design plan, the flow rate of the fishway is mainly controlled by the water level of the upstream reservoir and is basically not affected by the changes in the downstream water level. When the water level in the reservoir is 8.7m, the flow rate of the fishway is 0.74m3 / s; when the water level in the reservoir is 8.0m, the flow rate of the fishway is 0.44m3 / s; under each working condition, the water depth of each pool 30 along the way meets the design requirement of not less than 1.0m; when the water level in the reservoir is 8.7m, when the downstream water level is lower than 0.18m, the flow velocity of the vertical seam 31 and the pool chamber 30 near the fishway inlet below the 1# rest pool 36 exceeds the design requirement, the maximum flow velocity of the vertical seam 31 is 1.66m / s, and the maximum flow velocity of the pool chamber 30 is 1.31m / s; the flow velocity at the fishway inlet gradually decreases with the increase of the downstream water level, the mainstream flow velocity at the inlet of working condition 6 is only 0.15m / s, which does not meet the design requirements, and the flow velocity at the fishway inlet in other working conditions is 0.21-0.69m / s; the water flow at the fishway outlet is smooth, the flow velocity is mostly within 0.1m / s, the water flow is relatively smooth, and it meets the design requirements.

[0147] In response to the problem of excessive flow rate in the lower section of the vertical seam 31 and the pool in the fishway design, optimization measures were proposed to reduce the bottom elevation of the fishway inlet [from -1.52m to -2.22m] and increase the slope of the most downstream straight section pool chamber 30 [from 1.95% to 3.24%]. By increasing the water depth of the pool chamber 30, the purpose of reducing the flow rate was achieved to meet the requirements. Under the operating conditions of working conditions 3 and 6 [high water level downstream], the flow rate at the fishway inlet was lower than the induced flow rate of migratory fish [0.2m / s], which did not meet the design requirements and required water replenishment at the fishway inlet. The minimum water replenishment flow rates of working conditions 3 and 6 were 0.7m3 / s and 1.0m3 / s, respectively.

[0148] In summary, the optimized overall layout structure and operation plan of the fishway are as follows: the structure of the canal fishway includes an eel way 24 and a vertical slot fishway 23. The migratory fish in the eel way 24 include eels and mitten crabs, and the migratory fish in the vertical slot fishway 23 include red-eyed trout and dace. The eel way 24 and the vertical slot fishway 23 are located on the same side of the canal. A climbing matrix 20 is provided in the eel way 2, one end of the eel way 2 is connected to the middle part of the vertical slot fishway 23, and the other end extends to the bottom of the canal. The part of the vertical slot fishway 23 located upstream of the eel way 2 is also provided with a climbing matrix 20. The eel way 2 and the part of the vertical slot fishway 23 located upstream of the eel way 2 together form a migratory channel.

[0149] The part of the vertical slot fishway 23 located upstream of the eel way 2 is provided with water retaining structures at intervals, and a pool chamber 30 is formed between adjacent water retaining structures. The water retaining structure includes a partition 32 and a guide plate 35 arranged opposite to each other, and the guide plate 35 is smaller in width than the partition 32. A vertical slot 31 for fish to pass through is provided between the partition 32 and the guide plate 35. A climbing matrix 20 is also provided in the pool chamber 30, and the climbing matrix 20 includes a plurality of rows of pile structures 22, wherein each row is provided with at least two pile structures 22 at intervals, and adjacent rows of the pile structures 22 are staggered with each other along the length direction of the vertical slot fishway (23).

[0150] A preferred solution is that the climbing matrix 20 includes a plurality of rows of pile structures 22 , wherein each row is provided with at least two pile structures 22 at intervals, and adjacent rows of pile structures 22 are staggered along the length direction of the eel way 24 or the vertical slot fishway 23 .

[0151] The structure of a canal fishway of the present application provides climbing assistance for eels by staggering the pile structures 22 and adjacent rows of pile structures 22 along the length direction of the eel way 24 or the vertical slot fishway 23. At the same time, compared with the bristle base, the pile structure 22 does not have bristles, so there is no debris blockage and it is easy to clean. In addition, the pile structure 22 can play a role in friction resistance, water flow concussion and diffusion to dissipate energy along the way, thereby improving the flow state and reducing the flow rate of the vertical slot 31 passing through the fish. The pile structure 22 can be a cylindrical tube or a pier, and the staggered pipes or piers designed at the bottom provide a fulcrum for the eels to climb. The pipes are preferably cylindrical tubes or frustum tubes. Figure 1 As shown, further preferably, a through hole 21 is provided on the upstream side of the frustum tube; the upper edge of the frustum tube and the edge of the through hole 21 are in arc transition; the height of the frustum tube is greater than the bottom diameter of the tubular structure, and the top diameter of the frustum tube is smaller than the bottom diameter of the frustum tube. A preferred solution: the bottom diameter of the pile structure 22 is greater than the top diameter of the pile structure 22.

[0152] A preferred solution is that the pile structure 22 includes a plurality of forwardly arranged frustum piles, the lower portion of the frustum piles is connected to the bottom of the migratory channel, the top of the frustum piles is closed, and the height of the frustum piles is greater than the bottom diameter of the frustum piles.

[0153] A preferred solution: the pile structure 22 is a tubular structure, the lower part of the tubular structure is connected to the bottom of the migratory channel, the upper part of the tubular structure is open, and a through hole 21 is provided on the upstream side of the tubular structure; the upper edge of the tubular structure and the edge of the through hole 21 are in arc transition; the height of the tubular structure is greater than the bottom diameter of the tubular structure, and the top diameter of the tubular structure is smaller than the bottom diameter of the tubular structure. The inner wall of the tubular structure can also assist eels in climbing, and a through hole 21 is provided on the upstream side of the tubular structure, which can provide better migratory conditions for small Hepu mitten crabs and eels, and at the same time, the tubular structure cooperates with the through hole 21 to better play the role of friction resistance along the way, water flow counteraction and diffusion to dissipate energy, and thus better improve the flow state and reduce the flow velocity of the vertical slit 31 through which fish pass. Preferably, the migratory channel includes a driving mechanism, a four-bar linkage, a base and a fishway bottom plate structure, the base and the fishway bottom plate structure are both inclined, the pile structure 22 is arranged on the fishway bottom plate structure, and the driving mechanism drives the four-bar linkage to drive the fishway bottom plate structure to slide back and forth with the base. The eelway 24 and the vertical slit fishway 23 are both arranged on the tailwater side of the power station 27 on the hub 1, which is the mainstream edge of the physical obstacle [sluice] under most working conditions, which better meets the conditions of attracting and entering fish.

[0154] In summary:

[0155] 1. Study the swimming ability of the target fish species in the fishway, and clarify the ecological characteristics of the migration of the target fish species at the hub. The main fish species in the fishway are downstream migratory fish [CA] flower eel, eel, and flower perch, upstream migratory fish [AN] seven-thread anchovy and flower mullet, and historically distributed freshwater fish red-eye trout and dace; the targets are also other estuary fish such as spotted mullet, Chinese black mullet, spotted tongue goby, silverfish, tongue goby, and half-ribbed Chinese [fish mang], as well as Hepu mitten crab. The fish season is from November to September of the following year. The main fish species in the vertical slot fishway 23 are 40-600mm, and the fish species in the eelway 24 are 100-500mm. By testing the swimming ability of major fish species such as sea bass, eel, red-eyed trout, and dace, as well as the fish currently distributed in this section of the river, the design indicators of the fishway at the hub were comprehensively determined: the flow velocity range of the fish holes / slits of the vertical slot fishway 23 is 0.54-1.37 m / s, and the average flow velocity can be about 1.0 m / s; the average flow velocity of the pool chamber 30 is 0.24-0.67 m / s; the inlet fish-attracting flow velocity should not be lower than the fish-sensing flow velocity of 0.2 m / s, and should be 0.35-0.73 m / s; the outlet flow velocity should not be still water, and should be 0.24-0.35 m / s; eels are fish with climbing habits, and the eel way 24 should not be simply designed based on the measured swimming ability, but can be designed as a steeper slope, but staggered cylindrical tubes or piers should be designed at the bottom to provide a fulcrum for their climbing.

[0156] 2. Design of fishway 2, a preliminary design of fishway structure is proposed, including the preliminary design of fishway plane and pool chamber 30 structure layout. The fishway at hub 1 adopts the left bank double fishway scheme, and the vertical slot fishway 23 and eel way 24 are arranged on the shore close to the tailwater of power station 27; the eel way 24 meets the vertical slot fishway 23 near the downstream observation room 34, and then merges into the vertical slot fishway 23. The design scheme of the vertical slot fishway 23 is: bottom slope 1:51.02, total length 458m, single inlet, bottom elevation -1.52m, single outlet, bottom elevation 7m; the fishway includes 120 pool chambers 30 and 4 rest pools 36. The cross section of the pool chamber 30 is a rectangular cross section, the bottom slope I = 1.96%, the thickness of the partition 32 and the guide plate 35 are both 30cm, the diversion angle is 30°, no pier heads are set at the ends of the partition 32 and the guide plate 35, and they are rounded with a radius R = 15cm; the net width of the pool chamber 30 is 3.0m, the length of the pool chamber 30 is 3.6m, the design water depth h is 1.0~3.36m, the design width of the vertical slot 31 is 45cm, and a pile structure 22 with a diameter of 15cm and a height of 10cm is set at the bottom. The center line spacing of the piles is 45cm, and they are arranged in two rows in a staggered manner. The design of Eelway 24 is as follows: at the intersection of the vertical retaining wall on the left bank and the downstream bank, 7 vertical entrances are set toward the bank, vertically upward from the riverbed bottom plate at -7.5m, with an entrance set every 1m; the main channel is an aluminum water trough with a length of 13m, a width of 0.37m and a height of 0.1m. The slope of the water trough is 15°. The water trough is covered with a cover. A plastic climbing matrix 20 is placed in the water trough. The matrix is ​​composed of staggered plastic pipes, and the water depth of the water trough pipes is greater than 3cm; Eelway 24 merges into the vertical slit fishway 23 at an elevation of 3.39m, and then the eels will use the vertical slit fishway 23 to continue upstream.

[0157] 3. Physical model test of local section of fishway project. Based on the preliminary design scheme, a local section model of fishway with a geometric scale of 1:4 was established, and the structural layout demonstration and optimization research of the pool chamber 30 of the vertical slit fishway 23 were carried out, and a recommended scheme for the pool chamber 30 structure was proposed. The preliminary design scheme of the vertical slit fishway 23, the pool chamber 30 scale, the width of the vertical slit 31, and the main bottom slope design are basically reasonable, meeting the target fish upstream requirements; the fishway flow rate is about 0.50m3 / s, and the velocity coefficient of the partition 32 is φ=0.97; the diversion angle is small, so that the average flow velocity of the vertical slit 31 is 1.11m / s, which is higher than the design requirements. The mainstream in the pool chamber 30 is straight and the efficiency effect is poor. At the same time, the circulation develops unilaterally, which can easily cause small fish to lose their way and delay the upstream time. In view of the problem that the diversion angle is small, resulting in the water flow conditions in the vertical slit 31 and the pool chamber 30 not meeting the fish upstream requirements, the diversion angle is adjusted and optimized with the optimization idea of ​​promoting the mainstream deflection in the pool chamber 30 and increasing the mainstream energy dissipation. After comparing multiple groups of optimization scheme tests, a recommended scheme for the structure of chamber 30 is proposed, which keeps the scale of chamber 30, the width of vertical seam 31 and the bottom slope of chamber 30 unchanged, and increases the diversion angle to 45°. Under this scheme, the average water level difference of chamber 30 is 0.07m, the average flow velocity of vertical seam 31 is 1.01m / s, and the flow velocity of vertical seam 31 is distributed between 0.99 and 1.06m / s. The flow velocity of vertical seam 31 meets the design index requirements, and the flow velocity coefficient φ=0.86 corresponds to a design water depth of 1m. The flow rate of vertical seam 31 is about 0.45m3 / s, which is about 7% lower than the design scheme.

[0158] 4. Fig.25 and Fig.26As shown in the figure, the overall model test of the fishway is based on the recommended scheme of the pool chamber 30 structure and the plane layout design scheme of the vertical slit fishway 23. A fishway overall model with a geometric scale of 1:15 is established, and the overall hydraulic characteristics test of the vertical slit fishway 23 is carried out to propose a recommended scheme for the overall layout of the fishway and operation suggestions. According to the design scheme, the flow rate of the fishway is mainly controlled by the water level of the upstream reservoir. Under the working condition of the reservoir water level of 8.7m, the flow rate of the fishway is 0.74m3 / s; under the working condition of the reservoir water level of 8.0m, the flow rate of the fishway is 0.44m3 / s; under each working condition, the water depth of each pool chamber 30 along the way meets the design requirement of not less than 1.0m; when the water level of the reservoir is 8.7m, when the water level below the dam is lower than 0.18m, the vertical slit 31 and pool chamber 3 in the lower section of the fishway (below the 1# rest pool 36) 0 flow rate mostly exceeds the design requirements, the maximum flow rate of vertical seam 31 is 1.66m / s, and the maximum flow rate of pool 30 is 1.31m / s; the flow rate at the fishway inlet gradually decreases with the increase of downstream water level, and the mainstream flow rate at the inlet of working condition 6 is only 0.15m / s, which does not meet the design requirements. The flow rate at the fishway inlet of other working conditions is 0.21-0.69m / s; the water flow at the fishway outlet is smooth, and the flow rate is mostly within 0.03-0.1m / s, which meets the design requirements. In view of the problem of excessive flow rate in the vertical seam 31 and the pool of the lower section of the fishway in the design plan, the overall layout of the fishway is recommended to reduce the bottom elevation of the fishway inlet from -1.52m to -2.22m and increase the slope of the most downstream straight section pool 30 (adjusted from 1.95% to 3.24%). Recommended solution: Under the operating conditions of working conditions 3 and 6, the inlet flow rate is lower than the fish induction flow rate, which makes it difficult to ensure the fish attracting effect at the fishway inlet. Water replenishment is required. The minimum water replenishment flow rates of working conditions 3 and 6 are 0.7m3 / s and 1.0m3 / s respectively. When it is impossible to set up inlet water replenishment measures, it is recommended to set up water flow propellers at the fishway inlet to meet the inlet fish attracting flow rate requirements.

[0159] Conclusion: The model test research project of the fishway project at the hub adopted a variety of technical means such as data analysis, on-site testing, and physical model testing to carry out four parts of research: 1. Research on the swimming ability of the target fish species passing through the fishway to clarify the migratory ecological characteristics of the fish passing through; 2. Design of fishway 2 scheme, and propose a preliminary design scheme for the fishway plane and the structure of chamber 30; 3. Physical model test of the local section of the fishway project, based on the preliminary design scheme, carry out the demonstration and optimization research on the structural layout of chamber 30 of vertical slot fishway 23, and propose a recommended scheme for the structure of chamber 30; 4. Overall model test research of the fishway, based on the preliminary design scheme and the recommended scheme for the structure of chamber 30, carry out the overall hydraulic characteristics test research of the vertical slot fishway 23, and propose a recommended scheme for the overall layout of the fishway and operation suggestions.

[0160] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for testing a local section model of a fishway, characterized in that: The following steps are included: S1. Prepare a preliminary design plan for the vertical slot fishway (23); S2. Designing a local cross-section physical model of the fishway project based on the preliminary design scheme; S3. Conduct a local section model test of the fishway, measure and evaluate the fishway parameters, and find the fishway parameters that exceed the standard and the reasons for the fishway parameters exceeding the standard, wherein the fishway parameters include the water level difference between the upstream and downstream of adjacent chambers (30), the flow velocity distribution of the vertical slits (31), the flow field distribution in the chamber (30), the flow state in the chamber (30) and the local water flow in the chamber (30), and the average water depth of each chamber (30), the average water level difference of each chamber (30), the flow velocity distribution of the vertical slits (31) of each chamber (30), and the flow field distribution in the chamber (30); S4. After improving the cause in S3, repeat S2-S4 until all fishway parameters meet the design requirements, and form a recommended solution for the pool chamber (30) structure based on the fishway parameters.

2. A fishway partial section model test method according to claim 1, characterized in that: The local section physical model of the fishway project is designed as a normal model, and the local section physical model of the fishway project is designed according to the gravity similarity criterion, and the overall model design of the fishway is checked for geometric similarity, water flow movement similarity and dynamic similarity.

3. A fishway partial section model test method according to claim 1, characterized in that: In step S2, based on the preliminary design scheme of the vertical slot fishway (23), the designed bottom slope I of the pool chamber (30), the average low tide level at the estuary, the operating water level at the outlet of the vertical slot fishway (23), and the lowest water depth in the pool chamber (30) are determined; the corresponding upstream designed low water level condition of the fishway, the corresponding downstream designed low water level condition of the fishway, and the most unfavorable design condition are determined, and based on the designed bottom slope I of the pool chamber (30), the average low tide level at the estuary, the operating water level at the outlet of the vertical slot fishway (23), the lowest water depth in the pool chamber (30), the corresponding upstream designed low water level condition of the fishway, the corresponding downstream designed low water level condition of the fishway, and the most unfavorable design condition, a local cross-section physical model of the fishway project is designed, wherein the most unfavorable design condition is a condition in which the volume of the energy dissipation water body is the minimum value on the basis of the unchanged geometric scale of the pool chamber (30).

4. A fishway partial section model test method according to claim 1, characterized in that: In step S3, when conducting a local section model test of the fishway, the upstream flat water channel and the downstream overflow plate are used to control the upstream and downstream water levels to be constant. Several water gauges are arranged along the local section model of the fishway to measure the water level in the pool chamber. The flow field in the pool chamber and the vertical slit flow field are collected at a single point using an acoustic Doppler flow meter.

5. A fishway partial section model test method according to claim 1, characterized in that: In step S3, the flow velocity distribution of the vertical slit (31) is evaluated as follows: Measuring the flow velocity of at least part of the vertical slits (31), arranging a plurality of measuring points at intervals along the water depth vertically on the center line of each vertical slit (31), and obtaining the flow velocity distribution and average flow velocity of the vertical slit (31) based on the measuring points; Based on the swimming ability test results of the target fish species, a recommended range of flow velocity distribution and a recommended average flow velocity value of the vertical slit (31) are obtained; evaluating whether the flow velocity distribution of the vertical slit (31) exceeds the recommended flow velocity distribution range of the vertical slit (31), and whether the average flow velocity of the vertical slit (31) is greater than the recommended value of the average flow velocity of the vertical slit (31); Based on the average flow velocity of the vertical fish-passing slit (31), the average water level difference of the baffle (32), the average flow rate of the fishway and the water volume of the pool chamber (30), the flow velocity coefficient φ of the baffle (32) and the unit water power dissipation E of the pool chamber (30) are obtained, and the flow velocity coefficient φ of the baffle (32) and the unit water power dissipation E of the pool chamber (30) meet the design requirements.

6. A fishway partial section model test method according to claim 5, characterized in that: When the flow rate in the vertical seam (31) on the downstream side of the pool chamber (30) or in the pool chamber (30) exceeds the standard, the water depth of the pool chamber (30) is increased and the flow rate in the pool chamber (30) is reduced.

7. A fishway partial section model test method according to claim 1, characterized in that: In step S3, the flow field distribution in the pool chamber (30) is evaluated as follows: A pool chamber (30) is selected to measure the surface flow field distribution thereof, N measuring lines are arranged along the width of the pool chamber (30), and L measuring points are arranged along the length of each measuring line of the pool chamber (30); Based on the test results of the measuring points, the mainstream entry form, mainstream path, circulation position, integrity of the recirculation zone and the impact of the recirculation zone on fish in the pool chamber (30) are evaluated, wherein the recirculation zone influence range K3 and the maximum flow velocity v of the recirculation zone are used. cmax To quantify the impact of the recirculation zone on fish.

8. A fishway partial section model test method according to claim 7, characterized in that: The influence range K3 of the recirculation zone and the maximum flow velocity v of the recirculation zone cmax To quantify the impact of the recirculation zone on fish, specifically: K3=L c B c / (LB), where L c is the maximum length of the recirculation zone, B c is the maximum width of the recirculation zone.

9. A fishway partial section model test method according to claim 8, characterized in that: The influence range of the reflow zone K3 is 0.12~0.17; the reflow intensity range is 0.18~0.24m / s.

10. A fishway partial section model test method according to claim 7, characterized in that: When the influence range of the recirculation zone is too large, based on the diversion angle at the vertical slit (31) in the preliminary design scheme, at least a second diversion angle and a third diversion angle are set, and the second diversion angle and the third diversion angle are respectively substituted into the local section physical model of the fishway project to form a new local section physical model of the fishway project, and the new local section model test of the fishway is carried out to obtain the average flow velocity of the vertical slit (31), the maximum flow velocity of the vertical slit (31), and the minimum flow velocity of the vertical slit (31) at each diversion angle, and obtain an optimized structural scheme, wherein the second diversion angle and the third diversion angle are both greater than the diversion angle at the vertical slit (31) in the preliminary design scheme.

11. A fishway partial section model test method according to claim 10, characterized in that: Based on the optimized structural scheme, the water level difference of the pool chamber (30), the flow velocity distribution of the vertical seam (31) and the flow field distribution in the pool chamber (30) are calculated, and it is confirmed whether the water level difference of the pool chamber (30), the flow velocity distribution of the vertical seam (31) and the flow field distribution in the pool chamber (30) meet the design requirements. If so, the optimized structural scheme is the recommended structural scheme for the pool chamber (30).

12. A fishway partial section model test method according to claim 7, characterized in that: Based on the test results of the measuring points, the minimum value of the mainstream flow in the pool chamber and the average flow velocity of the vertical seams are obtained. The energy dissipation rate of the pool chamber is reflected by the ratio of the minimum value of the mainstream flow in the pool chamber to the average flow velocity of the vertical seams, and the energy dissipation rate of the pool chamber is obtained.

13. A fishway partial section model test method according to any one of claims 1 to 12, characterized in that: The fishway (2) in the preliminary design of the fishway includes an eel way (24) and a vertical slot fishway (23). The migratory fish in the eel way (24) include eels and mitten crabs, and the migratory fish in the vertical slot fishway (23) include red-eyed trout and dace. One end of the eel way (24) is connected to the middle of the vertical slot fishway (23), and the other end extends to the bottom of the canal.

14. A fishway partial section model test method according to claim 13, characterized in that: The recommended scheme for the structure of the pool chamber (30) is as follows: a water retaining structure is arranged at intervals in the part of the vertical slot fishway (23) located upstream of the eel way (24), and a pool chamber (30) is formed between adjacent water retaining structures. The water retaining structure includes a partition (32) and a guide plate (35) arranged opposite to each other, the guide plate (35) is smaller in width than the partition (32), and a vertical slot (31) for fish to pass through is provided between the partition (32) and the guide plate (35). A climbing matrix (20) is also provided in the pool chamber (30), and the climbing matrix (20) includes a plurality of rows of pile structures (22), wherein each row is provided with at least two pile structures (22) at intervals, and adjacent rows of the pile structures (22) are staggered with each other along the length direction of the vertical slot fishway (23).

15. A fishway partial section model test method according to claim 14, characterized in that: The flow guide angle of the vertical slit (31) is 45°.

Images