A "slot-hole-weir" combined fishway with four fish passages

Abstract

The "slit-hole-weir" combined fishway with four fish passages belongs to the field of fishway design. The present invention provides four fish passages for fish migration upstream by arranging four vertical slits, two inclined horizontal baffles with bottom openings, two inclined rectangular weirs with bottom openings, and two rectangular energy dissipation piers in each pool chamber, providing fish with more sufficient space for migration upstream, and reducing the flow velocity and turbulence in the mainstream area of ​​the pool chamber by sharing the flow, and can also further reduce the flow velocity and turbulence in the mainstream area by promoting the lateral / longitudinal diffusion and energy consumption of the water flow. It can improve the upstream success rate of the entire fish community (including fish with strong swimming ability and fish with weak swimming ability). The "slit-hole-weir" combined fishway with four fish passages proposed by the present invention helps to reduce the adverse effects of water conservancy projects on the river ecological environment, biodiversity and fishery resources.

Description

Technical Field

[0001] The present invention belongs to the field of fishway design, and particularly relates to a "slit-hole-weir" combined fishway with four fish passageways in each pool chamber. Background Art

[0002] By arranging fishways, the adverse impacts of hydraulic structures such as sluices, dams, and weirs on the river ecological environment, biodiversity, and fishery resources can be significantly reduced. The goal of fishway design has changed from only considering high-priority fish in the early stage to the current requirement of protecting the biodiversity of the entire fish community in the river. Traditional technical fishways have disadvantages such as a single flow pattern, a relatively large flow velocity in the main flow area, fewer fish passage targets, and lower fish passage efficiency. Due to factors such as large land occupation, high project cost, and difficulty in adapting to large fluctuations in upstream / downstream water levels, the natural / ecological fishways are only applicable to some water conservancy projects. The combined fishway has the advantages of a rich flow pattern in the pool chamber and being suitable for the upstream migration of various fish, but its structure is complex, the design is difficult, and so far, no combined fishway has been widely recognized and applied worldwide.

[0003] Traditional technical fishways include types such as Daniel fishways, overflow weir fishways, bottom / sunken orifice fishways, and vertical slit fishways. Among them, the Daniel fishway is provided with baffles and bottom sills on the trough wall and trough bottom, and its structure is simple, easy to install and construct, but it has poor adaptability to changes in upstream and downstream water levels, and the internal water flow is violently turbulent, only suitable for medium and large-sized fish with strong swimming ability. The overflow weir fishway can achieve fish passage over the weir crest, but it is difficult to adapt to large fluctuations in upstream / downstream water levels and the energy dissipation is not sufficient, only suitable for fish that like surface migration and have a jumping habit. The bottom / sunken orifice fishway is provided with fish passage holes completely submerged at the bottom, which can adapt to large fluctuations in upstream and downstream water levels, but its energy dissipation is not sufficient, only suitable for medium and large-sized fish that migrate at the bottom. The vertical slit fishway is provided with partitions and guide plates on the side wall and bottom plate, which can adapt to significant changes in upstream and downstream water levels and can achieve fish passage at the full water depth. However, the vertical slit is easily blocked by debris and needs to be cleaned regularly, and the flow velocity amplitude and turbulence level in the main flow area of the vertical slit are still relatively large, only suitable for fish with strong swimming ability to pass through. The present invention innovatively proposes a "slit-hole-weir" combined fishway with four fish passageways. The flow velocity amplitude and turbulence level in the main flow area of this fishway are not only much lower than those of conventional vertical slit fishways (such as Figure 7As shown in the figure, it is also somewhat lower than Patent CN202111662798.2 (a combined fishway with multiple vertical slits and rectangular weirs), Patent CN202111662849.1 (a vertical slit fishway with H-shaped piers and short baffles), and Patent CN202410638536.X (a double-sided symmetric multi-vertical slit fishway with trapezoidal diversion piers and gradually expanding and contracting cross-sections). A detailed comparison of the different hydrodynamic parameters in the fishway chambers of the above five structural types is shown in Table 1. Therefore, the "slit-hole-weir" combined fishway with four fish passage channels proposed by the present invention can significantly reduce the flow velocity and turbulence in the main flow area, is suitable for the upstream migration of the entire fish community (including fish with strong swimming ability and fish with weak swimming ability), helps to maintain the exchange of substances, energy, and genes between the upstream and downstream of hydraulic structures, and reduces the adverse effects of water conservancy projects on the river ecological environment, biodiversity, and fishery resources. Summary of the Invention

[0004] The present invention aims to propose a fishway solution that can meet the upstream migration of the entire fish community (including fish with strong swimming ability and fish with weak swimming ability) in the river, that is, to invent a "slit-hole-weir" combined fishway with four fish passage channels. The "slit-hole-weir" combined fishway proposed by the present invention has the respective advantages of an overflow weir fishway, a bottom / submerged hole fishway, a vertical slit fishway, and a multi-vertical slit fishway. The "slit-hole-weir" combined fishway is provided with four vertically staggered vertical slits, two inclined horizontal baffles with orifices arranged in a staggered manner, and two inclined rectangular weirs with orifices arranged in a staggered manner in each chamber, providing four fish passage channels (i.e., the "S-shaped slit passage", the "S-shaped weir passage", the "first orifice passage", and the "second orifice passage") for the upstream migration of fish, which is beneficial to providing a more sufficient upstream migration space for fish, and can also reduce the flow velocity amplitude and turbulence level in the main flow area of the chamber by sharing the flow. In addition, by providing two rectangular energy dissipation piers in each chamber, it is also possible to promote the lateral / longitudinal diffusion and energy consumption of the flow through the orifice and the flow over the weir, further significantly reducing the flow velocity and turbulence in the fishway. The "slit-hole-weir" combined fishway designed by the present invention can provide up to four upstream migration channels and widely distributed rest areas for fish in each chamber. The flow velocity amplitude and turbulence level of the main flow in the chamber can simultaneously meet the requirements of fish with strong swimming ability and fish with weak swimming ability for hydrodynamic conditions. In addition, the "slit-hole-weir" combined fishway can also provide a more extensive and reasonable rest area in terms of spatial distribution for fish with different swimming abilities in the chamber, further significantly improving the upstream success rate of the entire fish community and the utilization rate of the fishway chamber.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows:

[0006] The "slit-orifice-weir" combined fishway with four fish passages proposed by the present invention includes a bottom plate 1, side wall surfaces 2, short baffles 3, a first downstream-facing retaining wall 4, a second downstream-facing retaining wall 5, an inclined transverse baffle 6 with orifices, an inclined rectangular weir 7 with orifices, and a rectangular energy dissipating pier 8 (see Figure 1 ). The bottom plate 1 and the side wall surfaces 2 together form a flow-through channel, which includes an "S-shaped slit passage", an "S-shaped weir passage", a "first orifice passage", and a "second orifice passage"; the flow-through channel is divided into multiple pool chambers with the upstream side of the first downstream-facing retaining wall 4 as the boundary; each pool chamber includes a bottom plate 1, two side wall surfaces 2, four short baffles 3 arranged in a staggered manner, a first downstream-facing retaining wall 4, a second downstream-facing retaining wall 5, two inclined transverse baffles 6 with orifices arranged in a staggered manner, two inclined rectangular weirs 7 with orifices arranged in a staggered manner, and two rectangular energy dissipating piers 8;

[0007] In each pool chamber, the first downstream-facing retaining wall 4 and the second downstream-facing retaining wall 5 are collinearly arranged and parallel to the side wall surface 2, with a gap left at their adjacent ends, and the first downstream-facing retaining wall 4 is located upstream of the second downstream-facing retaining wall 5; the first short baffle 3 and the third short baffle 3 are both fixed to the first side wall surface 2 and are respectively located at the middle positions corresponding to the first downstream-facing retaining wall 4 and the second downstream-facing retaining wall 5, the second short baffle 3 and the fourth short baffle 3 are fixed on the side surface of the second downstream-facing retaining wall 5 facing the first side wall surface 2, and their end faces are flush with the two end faces of the second downstream-facing retaining wall 5, and the first short baffle 3, the second short baffle 3, the third short baffle 3, and the fourth short baffle 3 are arranged in sequence from upstream to downstream; the two ends of the other side surface of the second downstream-facing retaining wall 5 are respectively connected to the first inclined transverse baffle 6 with orifices and the second inclined rectangular weir 7 with orifices, and both the first inclined transverse baffle 6 with orifices and the second inclined rectangular weir 7 with orifices form an acute angle with the reverse water flow direction, and their positions respectively correspond to the positions of the two short baffles 3 on the second downstream-facing retaining wall 5, and the first inclined transverse baffle 6 with orifices is located upstream of the second inclined rectangular weir 7 with orifices. One end of the second inclined transverse baffle 6 with orifices and the first inclined rectangular weir 7 with orifices are respectively connected to the ends of the second inclined rectangular weir 7 with orifices and the first inclined transverse baffle 6 with orifices, and the other ends are respectively connected to the second side wall surface 2. Both the second inclined transverse baffle 6 with orifices and the first inclined rectangular weir 7 with orifices form an acute angle with the water flow direction. The two rectangular energy dissipating piers 8 are respectively arranged downstream of the junctions of the two pairs of inclined transverse baffles 6 with orifices and inclined rectangular weirs 7 with orifices.

[0008] Bottom holes are opened at the centers of the bottoms of the inclined transverse baffle 6 with orifices and the inclined rectangular weir 7 with orifices.

[0009] Furthermore, the "S-shaped through-seam channel" in each pool chamber is jointly composed of four vertical vertical seams arranged in a staggered manner along the water flow direction (see details in Figure 2 ); among them, the first vertical seam 9 is composed of the first short baffle 3 and the first downstream-facing retaining wall 4, the second vertical seam 10 is composed of the first side wall surface 2 and the second short baffle 3, the third vertical seam 11 is composed of the second downstream-facing retaining wall 5 and the third short baffle 3, and the fourth vertical seam 12 is composed of the first side wall surface 2 and the fourth short baffle 3. The "S-shaped through-seam channel" is located in the left area of the pool chamber (viewed from upstream to downstream along the water flow direction), and is overall distributed in an "S" shape.

[0010] Furthermore, the "S-shaped over-weir channel" in each pool chamber is jointly composed of two inclined rectangular weirs 7 with orifices arranged in a staggered manner along the water flow direction (see details in Figure 2 ); among them, the angle between the first inclined rectangular weir 7 with orifices and the water flow direction is 60° for all, and the angle between the second inclined rectangular weir 7 with orifices and the reverse water flow direction is 60° for all. The "S-shaped over-weir channel" is located in the middle and right areas of the pool chamber, and is overall distributed in an "S" shape.

[0011] Furthermore, the "first through-hole channel" in each pool chamber is jointly composed of the first bottom hole 15 and the third bottom hole 17 arranged along the water flow direction (see details in Figure 2 ); among them, the first bottom hole 15 is located at the bottom of the first inclined transverse baffle 6 with orifices, the third bottom hole 17 is located at the bottom of the second inclined rectangular weir 7 with orifices, and the angles between the first bottom hole 15 and the third bottom hole 17 and the reverse water flow direction are both 60°. When the fish passes through the bottoms of the inclined transverse baffle 6 and the inclined rectangular weir 7, the path trajectory is "S-shaped", and the mainstream passing through the first bottom hole 15 and the third bottom hole 17 is also overall distributed in an "S" shape. The "first through-hole channel" is located in the middle area of the pool chamber.

[0012] Furthermore, the "second through-hole channel" in each pool chamber is jointly composed of the second bottom hole 16 and the fourth bottom hole 18 arranged along the water flow direction (see details in Figure 2 ); among them, the second bottom hole 16 is located at the bottom of the first inclined rectangular weir 7 with orifices, the fourth bottom hole 18 is located at the bottom of the second inclined transverse baffle 6 with orifices, and the angles between the second bottom hole 16 and the fourth bottom hole 18 and the water flow direction are both 60°. When the fish passes through the bottoms of the inclined rectangular weir 7 and the inclined transverse baffle 6, the path trajectory is "S-shaped", and the mainstream passing through the second bottom hole 16 and the fourth bottom hole 18 is also overall distributed in an "S" shape. The "second through-hole channel" is located in the right area of the pool chamber.

[0013] Further, the two rectangular energy dissipating piers 8 in each pool chamber are located transversely in the connection and junction area between the inclined transverse baffle 6 with orifices and the inclined rectangular weir 7 with orifices, and are located downstream of the inclined transverse baffle 6 with orifices and the inclined rectangular weir 7 with orifices in the flow direction; the cross-section of the rectangular energy dissipating pier 8 is square.

[0014] Further, the longitudinal slope range of the bottom plate 1 is 1% - 10%; the length-width ratio of each pool chamber is 3.0:2.2.

[0015] Further, the width b of the short baffle 3 c has a ratio of 0.25:2.2 to the pool chamber width B (see details in Figure 3 and Figure 4 ); the thickness I of all baffles and retaining walls 0 has a ratio of 0.2:3.0 to the pool chamber length L; the height H of all baffles and retaining walls has a ratio of 3.0:2.2 to the pool chamber width B; the length I of the first longitudinal retaining wall 4 3 has a ratio of 0.8:3.0 to the pool chamber length L; the length I of the second longitudinal retaining wall 5 4 has a ratio of 1.52:3.0 to the pool chamber length L; the distance I between the downstream side of the first short baffle 3 and the upstream side of the second short baffle 3 (or the distance I between the downstream side of the fourth short baffle 3 and the upstream side of the first short baffle 3 of the next pool chamber 1 ) 1 has a ratio of 0.64:3.0 to the pool chamber length L; the distance I between the downstream side of the second short baffle 3 and the upstream side of the third short baffle 3 (or the distance I between the downstream side of the third short baffle 3 and the upstream side of the fourth short baffle 3 2 ) 2 has a ratio of 0.46:3.0 to the pool chamber length L; the vertical seam widths of the four staggered vertical seams are all b s , and b s has a ratio of 0.59:2.2 to the pool chamber width B.

[0016] Further, the included angle θ between the second inclined transverse baffle 6 with orifices and the direction of the flowing water is 60° (see details in Figure 3 and Figure 4 ); the length of the inclined transverse baffle 6 with orifices has a ratio of 0.67:2.2 to the pool chamber width B; the projected length d of the inclined transverse baffle 6 with orifices in the transverse direction 1 has a ratio of 0.58:2.2 to the pool chamber width B; the length L of all bottom orifices o has a ratio of 0.30:2.2 to the pool chamber width B; the width b of all bottom orifices o has a ratio of 0.20:2.2 to the pool chamber width B; the height h of all bottom orifices oThe ratio to the baffle height H is 0.30:3.0.

[0017] Furthermore, the angle θ between the first inclined rectangular weir 7 with orifices and the water flow direction is 60° (see Figure 3 and Figure 4 ); the length L of the inclined rectangular weir 7 with orifices w has a ratio to the chamber width B of 0.67:2.2; the projected length d of the inclined rectangular weir 7 with orifices in the transverse direction 1 has a ratio to the chamber width B of 0.58:2.2; the width b of the inclined rectangular weir 7 with orifices w has a ratio to the chamber width B of 0.20:2.2; the height h of the inclined rectangular weir 7 with orifices w has a ratio to the baffle height H of 0.60:3.0.

[0018] Furthermore, the ratio of the height H of the rectangular energy dissipating pier 8 to the chamber width B is 3.0:2.2; the cross-section of the rectangular energy dissipating pier 8 is square, and the ratio of its side length d to the chamber width B is 0.30:2.2; the distance I between the rectangular energy dissipating pier 8 and the connection junction of the inclined rectangular weir 7 with orifices and the inclined transverse baffle 6 with orifices 5 has a ratio to the chamber length L of 0.379:3.0.

[0019] Advantages of the present invention:

[0020] (1) Traditional fishways of the technical type have disadvantages such as a single flow pattern, a relatively large flow velocity in the main flow area, fewer fish passage targets, and a relatively low fish passage efficiency. The "slot-hole-weir" combined fishway with four fish passage channels proposed by the present invention innovatively arranges an inclined transverse baffle with orifices, an inclined rectangular weir with orifices, a rectangular energy dissipating pier, a short baffle, a first longitudinal retaining wall, and a second longitudinal retaining wall, which greatly promotes the diffusion and energy consumption of the flow through the slot, the flow through the hole, and the flow over the weir in different directions, and can significantly reduce the flow velocity amplitude and turbulence level in the main flow area of the fishway, so as to meet the requirements of the entire fish community in the river (including fish with strong swimming ability and fish with weak swimming ability) for the hydrodynamic conditions in the fishway during upstream migration, and it is an excellent "multi-target population" combined fishway.

[0021] (2) The "slit - orifice - weir" combined fishway sets four vertically staggered vertical slits, two inclined transverse baffles with orifices arranged staggeredly, two inclined rectangular weirs with orifices arranged staggeredly, and two rectangular energy dissipating piers in each pool chamber. It can provide four fish - passing channels for fish to migrate upstream (i.e., the "S - shaped slit - passing channel" that can achieve fish - passing through the full water depth, the "S - shaped weir - passing channel" that can achieve fish - passing in the middle and upper layers, the "first orifice - passing channel" and the "second orifice - passing channel" that can achieve fish - passing in the lower layer). It not only helps to provide a more sufficient space for fish to migrate upstream, but also helps to reduce the flow velocity and turbulence in the main flow area of the pool chamber by sharing the flow, and can improve the fish - passing efficiency of the fishway.

[0022] (3) The "slit - orifice - weir" combined fishway has a very high utilization efficiency of flow, and is especially suitable for seasonal water - shortage areas. Moreover, the recirculation area with low flow velocity and low turbulence in the fishway pool chamber of the present invention is more extensive and sufficient in spatial distribution, so it can provide a more reasonable rest area for fish to migrate upstream. Brief Description of the Drawings

[0023] Figure 1 It is a three - dimensional schematic diagram of a single pool chamber of the "slit - orifice - weir" combined fishway with four fish - passing channels of the present invention;

[0024] Figure 2 It is a composition diagram of different fish - passing channels in a single pool chamber of the "slit - orifice - weir" combined fishway with four fish - passing channels of the present invention;

[0025] Figure 3 It is a detailed structural schematic diagram of the inclined transverse baffle / inclined rectangular weir with orifices of the "slit - orifice - weir" combined fishway with four fish - passing channels of the present invention;

[0026] Figure 4 It is a two - dimensional plane schematic diagram of a single pool chamber of the "slit - orifice - weir" combined fishway with four fish - passing channels of the present invention;

[0027] Figure 5 It is a three - dimensional schematic diagram of multiple pool chambers of the "slit - orifice - weir" combined fishway with four fish - passing channels of the present invention;

[0028] Figure 6 It is a two - dimensional plane schematic diagram of multiple pool chambers of the "slit - orifice - weir" combined fishway with four fish - passing channels of the present invention.

[0029] Figure 7 It is a schematic diagram of a conventional vertical - slit fishway.

[0030] In the figure: 1 bottom plate; 2 side wall surface; 3 short baffle; 4 first longitudinal flow direction retaining wall; 5 second longitudinal flow direction retaining wall; 6 inclined transverse baffle with orifice; 7 inclined rectangular weir with orifice; 8 rectangular energy dissipating pier; 9 first vertical seam; 10 second vertical seam; 11 third vertical seam; 12 fourth vertical seam; 13 first weir body; 14 second weir body; 15 first bottom hole; 16 second bottom hole; 17 third bottom hole; 18 fourth bottom hole; 19 short baffle of conventional vertical seam type fishway; 20 long baffle of conventional vertical seam type fishway.

[0031] B width of the pool chamber; L length of the pool chamber; H height of the baffle, retaining wall, side wall surface and rectangular energy dissipating pier; I 0 Thickness of the baffle and retaining wall; b s Width of the vertical seam; b c Width of the short baffle; I 1 Distance between the downstream side of the first short baffle and the upstream side of the second short baffle (or between the downstream side of the fourth short baffle and the upstream side of the first short baffle of the next pool chamber); I 2 Distance between the downstream side of the second short baffle and the upstream side of the third short baffle (or between the downstream side of the third short baffle and the upstream side of the fourth short baffle); I 3 Length of the first longitudinal flow direction retaining wall; I 4 Length of the second longitudinal flow direction retaining wall; I 5 Distance between the rectangular energy dissipating pier and the connection between the inclined rectangular weir with orifice and the inclined transverse baffle with orifice; θ angle between the inclined transverse baffle with orifice and the inclined rectangular weir with orifice and the water flow direction; L o Length of the orifice; b o Width of the orifice; h o Height of the orifice; L w Length of the inclined rectangular weir with orifice; b w Width of the inclined rectangular weir with orifice; h w Height of the inclined rectangular weir with orifice; d side length of the square cross-section of the rectangular energy dissipating pier; d 1 Projection length in the transverse direction of the inclined transverse baffle with orifice and the inclined rectangular weir with orifice. Detailed implementation manner

[0032] The following further describes the detailed implementation manner of the present invention in combination with the accompanying drawings and the content of the invention.

[0033] As Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6As shown in the figure, the "slit-orifice-weir" combined fishway with four fish passages includes: a bottom plate 1; side wall surfaces 2; short baffles 3; a first longitudinal flow-retaining wall 4; a second longitudinal flow-retaining wall 5; an inclined transverse baffle 6 with orifices; an inclined rectangular weir 7 with orifices; and rectangular energy dissipation piers 8, and all connections are fixedly connected.

[0034] Figure 1 This is a three-dimensional schematic diagram of a single chamber of the "slit-orifice-weir" combined fishway with four fish passages of the present invention. Figure 2 This is a composition diagram of different fish passage components in a single chamber of the "slit-orifice-weir" combined fishway with four fish passages of the present invention. The arrow direction in the figure is the water flow direction, and the longitudinal slope of the fishway bottom plate 1 is 2%. The fishway chamber is divided into a left region and a right region (viewed from upstream to downstream along the longitudinal flow direction) by the first longitudinal flow-retaining wall 4 and the second longitudinal flow-retaining wall 5 alternately arranged in the middle region of the fishway. Four short baffles 3 are arranged in a staggered manner along the longitudinal flow direction in the left region of the chamber, and four vertically staggered slits can be formed, namely the first slit 9, the second slit 10, the third slit 11, and the fourth slit 12 (see Figure 2). When the water flow passes through the "vertical slit" in the left area of the pool chamber and flows towards the fishway outlet, an over-slit channel in the fishway pool chamber is formed. Obviously, the water flow in the over-slit channel presents an "S-shaped" distribution on the plane, so this channel is also called the "S-shaped over-slit channel". Two inclined transverse baffles 6 with orifices, two inclined rectangular weirs 7 with orifices, and two rectangular energy dissipating piers 8 are arranged in a staggered manner along the downstream direction in the right area of the pool chamber, thus forming two staggered inclined rectangular weir bodies (the first weir body 13 and the second weir body 14) and four inclined rectangular orifices arranged at the bottom (the first bottom orifice 15, the second bottom orifice 16, the third bottom orifice 17, and the fourth bottom orifice 18). When the water flow passes through the upper part of the inclined rectangular weir body in the right area of the pool chamber and flows towards the fishway outlet, an over-weir channel in the fishway pool chamber is formed. Obviously, the water flow in the over-weir channel presents an "S-shaped" distribution on the plane, so this channel is also called the "S-shaped over-weir channel". Due to the separation effect of the rectangular energy dissipating pier 8, the "S-shaped over-weir channel" will be subdivided into two sub-channels (both can be used for fish to migrate upstream) in the adjacent area of the rectangular energy dissipating pier 8. When the water flow passes through the inclined rectangular orifices arranged at the bottom in the right area of the pool chamber and flows towards the fishway outlet, the "first over-orifice channel" (the first bottom orifice 15 and the third bottom orifice 17) and the "second over-orifice channel" (the second bottom orifice 16 and the fourth bottom orifice 18) in the fishway pool chamber are formed. Since all four inclined rectangular orifices form an angle θ = 60° with the water flow direction, the water flow in the "first over-orifice channel" and the "second over-orifice channel" also presents an "S-shaped" distribution on the plane, so they are called the "first over-orifice channel" and the "second over-orifice channel". A smaller recirculation area will be formed on the downstream side of all the short baffles 3; a smaller recirculation area will also be formed on the upstream side of all the first downstream retaining walls 4; a larger recirculation area will be formed on the downstream side of all the inclined transverse baffles 6 with orifices; the flow velocity and turbulence in the recirculation area are relatively low, which can be used as a rest area for different fish to recover energy and relieve fatigue during the upstream migration process. Generally speaking, on the one hand, the "slit-orifice-weir" combined fishway has four fish passage channels (i.e., the "S-shaped over-slit channel", the "S-shaped over-weir channel", the "first over-orifice channel", and the "second over-orifice channel") in each pool chamber, which is not only beneficial to providing more sufficient migration upstream space for fish, but also beneficial to reducing the flow velocity and turbulence in the main flow area of the pool chamber by sharing the flow rate. On the other hand, the "slit-orifice-weir" combined fishway can greatly promote the lateral / longitudinal diffusion and energy consumption of the over-orifice water flow and the over-weir water flow by setting two rectangular energy dissipating piers 8 in each pool chamber, and further significantly reduce the flow velocity and turbulence in the main flow area. In addition, the "slit-orifice-weir" combined fishway can also provide a more extensive and reasonable rest area for fish in the spatial distribution in the pool chamber, thereby further improving the upstream success rate of the entire fish community (including fish with strong swimming ability and fish with weak swimming ability) and the utilization rate of the fishway pool chamber.

[0035] Figure 3Schematic diagram of the detailed structure of the inclined transverse baffle 6 with orifices / inclined rectangular weir 7 with orifices of the "slit - hole - weir" combined fishway with four fish - passing channels of the present invention. Figure 4 Two - dimensional plane schematic diagram of a single chamber of the "slit - hole - weir" combined fishway with four fish - passing channels of the present invention. Chamber width B = 2.20 m; Chamber length L = 3.00 m; Heights H of the baffle, retaining wall, side wall surface 2 and rectangular energy - dissipating pier 8 = 3.00 m; Thickness I of the baffle and retaining wall 0 = 0.20 m; Width b of the vertical slit s = 0.59 m; Width b of the short baffle 3 c = 0.25 m; Distance I between the downstream side of the first short baffle 3 and the upstream side of the second short baffle 3 (or the distance I between the downstream side of the fourth short baffle 3 and the upstream side of the first short baffle 3 of the next chamber 1 ). Distance I 1 = 0.64 m; Distance I between the downstream side of the second short baffle 3 and the upstream side of the third short baffle 3 (or the distance I between the downstream side of the third short baffle 3 and the upstream side of the fourth short baffle 3 2 ). Distance I 2 = 0.80 m; Length I of the first longitudinal retaining wall 4 3 = 1.52 m; Length I of the second longitudinal retaining wall 5 4 = 0.379 m; Distance I between the rectangular energy - dissipating pier 8 and the connection between the inclined rectangular weir 7 with orifices and the inclined transverse baffle 6 with orifices 5 = 0.379 m; Angle θ between the inclined transverse baffle 6 with orifices and the inclined rectangular weir 7 with orifices and the longitudinal direction = 60°; Length L of the orifice o = 0.30 m; Width b of the orifice o = 0.20 m; Height h of the orifice o = 0.30 m; Length L of the inclined rectangular weir 7 with orifices w = 0.67 m; Width b of the inclined rectangular weir 7 with orifices w = 0.20 m; Height h of the inclined rectangular weir 7 with orifices w = 0.60 m; Side length d of the square cross - section of the rectangular energy - dissipating pier 8 = 0.30 m; Projected length d in the transverse direction of the inclined transverse baffle 6 with orifices and the inclined rectangular weir 7 with orifices 1 = 0.58 m.

[0036] The results of numerical simulation studies show that when the flow rate Q = 0.6 m 3 / s ~ 1.0 m 3When the bottom slope S = 1.67%, the comparison results of the average water depth, maximum velocity, average velocity, maximum turbulence kinetic energy, and average turbulence kinetic energy of the fishways with five structural forms inside the pool chamber are shown in Table 1:

[0037] Table 1 Comparison of water depth, velocity, and turbulence kinetic energy of fishways with five structural forms

[0038]

[0039] It is found by comparison that under different flow conditions, the average water depth of the "slit-hole-weir" combined fishway with four fish passage channels proposed by the present invention is significantly higher than that of the other four structural forms of fishways. This shows that when maintaining the same average water depth of the pool chamber, the operating flow rate of the "slit-hole-weir" combined fishway is lower, that is, the utilization efficiency of the "slit-hole-weir" combined fishway for flow rate is significantly higher than that of the other four structural forms of fishways. Therefore, the "slit-hole-weir" combined fishway is particularly suitable for seasonal water shortage areas. In addition, under different flow conditions, the "slit-hole-weir" combined fishway with four fish passage channels proposed by the present invention is significantly smaller than the traditional vertical slit fishway in terms of maximum velocity, average velocity, maximum turbulence kinetic energy, and average turbulence kinetic energy, and is also smaller to a certain extent than Patent CN202111662849.1 (a vertical slit fishway with H-shaped piers and short baffles), Patent CN202111662798.2 (a combined fishway with multiple vertical slits and rectangular weirs), and Patent CN202410638536.X (a double-sided symmetric multi-vertical slit fishway with trapezoidal diversion piers and gradually expanding and contracting cross-sections). When the main flow area of the fishway pool chamber has lower velocity and turbulence, it can effectively reduce the energy consumption of fish during upstream migration, which helps to improve the upstream success rate of the entire fish community in the river (including fish with strong swimming ability and fish with weak swimming ability). Therefore, the "slit-hole-weir" combined fishway with four fish passage channels proposed by the present invention is an excellent "multi-target population" fishway, which is not only very conducive to the upstream migration of fish populations with weak swimming ability, but also particularly suitable for seasonal water shortage areas (such as northern China).

Claims

1. A "slot-hole-weir" combined fishway with four fish passages, characterized in that: The invention comprises a bottom plate (1), a side wall surface (2), a short baffle (3), a first downstream retaining wall (4), a second downstream retaining wall (5), an inclined transverse baffle with an orifice (6), an inclined rectangular weir with an orifice (7) and a rectangular energy dissipation pier (8); the bottom plate (1) and the side wall surface (2) together form a flow passage, and the flow passage comprises an "S-shaped gap passage", an "S-shaped weir passage", a "first hole passage" and a "second hole passage". The flow passage is divided into a plurality of chambers with the upstream side of the first downstream retaining wall (4) as the boundary; each chamber comprises a bottom plate (1), two side walls (2), four staggered short baffles (3), a first downstream retaining wall (4), a second downstream retaining wall (5), two staggered inclined transverse baffles with orifices (6), two staggered inclined rectangular weirs with orifices (7), and two rectangular energy dissipation piers (8); In each pool chamber, a first downstream retaining wall (4) and a second downstream retaining wall (5) are arranged in a colinear manner and are parallel to the side wall surface (2), and a gap is left between the adjacent ends of the two. The first downstream retaining wall (4) is located upstream of the second downstream retaining wall (5); the first short baffle (3) and the third short baffle (3) are both fixed on the first side wall surface (2) and are respectively located in the middle positions corresponding to the first downstream retaining wall (4) and the second downstream retaining wall (5), and the second short baffle (3) and the fourth short baffle (3) are respectively located in the middle positions corresponding to the first downstream retaining wall (4) and the second downstream retaining wall (5). A short baffle (3) is fixed on the side of the second downstream retaining wall (5) facing the first side wall (2), and the end face is flush with the two end faces of the second downstream retaining wall (5); the first short baffle (3), the second short baffle (3), the third short baffle (3), and the fourth short baffle (3) are arranged in sequence from upstream to downstream; the two ends of the other side face of the second downstream retaining wall (5) are respectively connected to the first inclined transverse baffle (6) with an orifice, the second inclined transverse baffle (6) with an orifice, and the second inclined transverse baffle (6) with an orifice. A rectangular weir (7), a first inclined transverse baffle with an orifice (6) and a second inclined rectangular weir with an orifice (7) both form an acute angle with the upstream direction of the water flow, and the positions of the two respectively correspond to the positions of the two short baffles (3) on the second downstream retaining wall (5), and the first inclined transverse baffle with an orifice (6) is located upstream of the second inclined rectangular weir with an orifice (7); one end of the second inclined transverse baffle with an orifice (6) and the first inclined rectangular weir with an orifice (7) are respectively connected to the end of the second inclined rectangular weir with an orifice (7) and the first inclined transverse baffle with an orifice (6), and the other ends are respectively connected to the second side wall surface (2); the second inclined transverse baffle with an orifice (6) and the first inclined rectangular weir with an orifice (7) both form an acute angle with the water flow direction; two rectangular energy dissipation piers (8) are respectively arranged downstream of the junction of the two pairs of inclined transverse baffles with orifices (6) and the inclined rectangular weir with orifices (7); A bottom hole is provided at the bottom center of the inclined transverse baffle (6) with an opening and the inclined rectangular weir (7) with an opening; The two rectangular energy dissipation piers (8) in each pool chamber are located in the connection and intersection area of ​​the inclined transverse baffle with orifices (6) and the inclined rectangular weir with orifices (7) in the transverse direction, and are located downstream of the inclined transverse baffle with orifices (6) and the inclined rectangular weir with orifices (7) in the flow direction; the cross section of the rectangular energy dissipation piers (8) is a square.

2. The "slot-hole-weir" combined fishway with four fish passages according to claim 1, characterized in that: The "S-shaped seam passage" in each pool chamber is composed of four vertical seams arranged in an alternating manner along the direction of the water flow; wherein the first vertical seam (9) is composed of the first short baffle (3) and the first downstream retaining wall (4), the second vertical seam (10) is composed of the first side wall surface (2) and the second short baffle (3), the third vertical seam (11) is composed of the second downstream retaining wall (5) and the third short baffle (3), and the fourth vertical seam (12) is composed of the first side wall surface (2) and the fourth short baffle (3); the "S-shaped seam passage" is located in the left area of ​​the pool chamber when viewed from upstream to downstream along the direction of the water flow, and is generally distributed in an "S" shape.

3. The "slot-hole-weir" combined fishway with four fish passages according to claim 1, characterized in that: The "S-shaped weir passage" in each pool chamber is composed of two inclined rectangular weirs (7) with orifices arranged alternately along the direction of the water flow; wherein the angle between the first inclined rectangular weir (7) with orifices and the water flow direction is 60°, and the angle between the second inclined rectangular weir (7) with orifices and the direction against the water flow is 60°; the "S-shaped weir passage" is located in the middle and right side areas of the pool chamber, and is distributed in an "S" shape as a whole.

4. The "slot-hole-weir" combined fishway with four fish passages according to claim 1, characterized in that: The "first through-hole channel" in each pool chamber is composed of a first bottom hole (15) and a third bottom hole (17) arranged along the downstream direction; wherein the first bottom hole (15) is located at the bottom of a first inclined transverse baffle (6) with an orifice, and the third bottom hole (17) is located at the bottom of a second inclined rectangular weir (7) with an orifice. The angles between the first bottom hole (15) and the third bottom hole (17) and the upstream direction are both 60 degrees. When the fish passes through the bottom of the inclined transverse baffle (6) and the inclined rectangular weir (7), the path trajectory is "S-shaped", and the mainstream passing through the first bottom hole (15) and the third bottom hole (17) is also "S-shaped" on the whole; the "first through-hole channel" is located in the middle area of ​​the pool chamber.

5. The "slot-hole-weir" combined fishway with four fish passages according to claim 1, characterized in that: The "second through-hole channel" in each pool chamber is composed of a second bottom hole (16) and a fourth bottom hole (18) arranged along the direction of the water flow; wherein the second bottom hole (16) is located at the bottom of the first inclined rectangular weir (7) with an orifice, and the fourth bottom hole (18) is located at the bottom of the second inclined transverse baffle (6) with an orifice. The angles between the second bottom hole (16) and the fourth bottom hole (18) and the direction of the water flow are both 60 degrees. When the fish passes through the bottom of the inclined rectangular weir (7) and the inclined transverse baffle (6), the path trajectory is "S-shaped", and the mainstream passing through the second bottom hole (16) and the fourth bottom hole (18) is also "S-shaped" on the whole; the "second through-hole channel" is located in the right area of ​​the pool chamber.

6. The "slot-hole-weir" combined fishway with four fish passages according to claim 2, characterized in that: The longitudinal slope of the bottom plate (1) ranges from 1% to 10%; the length-to-width ratio of each pool chamber is 3.0:2.2; the width b of the short baffle (3) is c The ratio of the thickness I0 of all baffles and retaining walls to the width B of the pool chamber is 0.25:2.2; the ratio of the thickness I0 of all baffles and retaining walls to the length L of the pool chamber is 0.2:3.0; the ratio of the height H of all baffles and retaining walls to the width B of the pool chamber is 3.0:2.2; the ratio of the length I3 of the first downstream retaining wall (4) to the length L of the pool chamber is 0.8:3.0; the ratio of the length I4 of the second downstream retaining wall (5) to the length L of the pool chamber is 1.52:3.0; the ratio of the distance I1 from the downstream side of the first short baffle (3) to the upstream side of the second short baffle (3) to the length L of the pool chamber is 0.64:3.0, the ratio of the distance I1 from the downstream side of the fourth short baffle (3) to the upstream side of the first short baffle (3) of the next pool chamber to the length L of the pool chamber is 0.64:3.0; the ratio of the distance I2 from the downstream side of the second short baffle (3) to the upstream side of the third short baffle (3) to the length L of the pool chamber is 0.46:3.0, and the ratio of the distance I2 from the downstream side of the third short baffle (3) to the upstream side of the fourth short baffle (3) to the length L of the pool chamber is 0.46:3.0; the vertical seam widths of the four staggered vertical seams are all b s , and b s The ratio to the pool chamber width B is 0.59:2.

2.

7. The "slot-hole-weir" combined fishway with four fish passages according to claim 1, characterized in that: The angle θ between the second inclined transverse baffle (6) with orifices and the direction of the water flow is 60°; the ratio of the length of the inclined transverse baffle (6) with orifices to the width B of the pool chamber is 0.67:2.2; the ratio of the horizontal projection length d1 of the inclined transverse baffle (6) with orifices to the width B of the pool chamber is 0.58:2.2; the length L of all bottom orifices o The ratio of the width of the pool chamber B is 0.30:2.2; the width of all bottom openings b o The ratio of the width of the pool chamber B is 0.20:2.2; the height of all bottom openings h o The ratio to the baffle height H is 0.30:3.

0.

8. The "slot-hole-weir" combined fishway with four fish passages according to claim 1, characterized in that: The angle θ between the first inclined rectangular weir (7) with an orifice and the downstream direction is 60°; the length L of the inclined rectangular weir (7) with an orifice is w The ratio of the projection length d1 of the inclined rectangular weir (7) with an orifice in the lateral direction to the width B of the pool chamber is 0.67:2.2; the ratio of the projection length d1 of the inclined rectangular weir (7) with an orifice in the lateral direction to the width B of the pool chamber is 0.58:2.2; the width b of the inclined rectangular weir (7) with an orifice is w The ratio of the width of the pool chamber B is 0.20:2.2; the height h of the inclined rectangular weir (7) with an orifice w The ratio to the baffle height H is 0.60:3.

0.

9. The "slot-hole-weir" combined fishway with four fish passages according to claim 1, characterized in that: The ratio of the height H of the rectangular energy dissipation pier (8) to the width B of the pool chamber is 3.0:2.2; the cross section of the rectangular energy dissipation pier (8) is a square, and the ratio of its side length d to the width B of the pool chamber is 0.30:2.2; the ratio of the distance I5 between the rectangular energy dissipation pier (8) and the inclined rectangular weir (7) with an orifice and the inclined transverse baffle (6) with an orifice to the length L of the pool chamber is 0.379:3.0.

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