Fishway with water-filled float gate for adapting to upstream water level changes

Abstract

The application discloses a fishway utilizing a water-filled floating body gate to adapt to upstream water level change, and belongs to the field of hydraulic engineering. The fishway comprises a fishway dam-passing section, an upstream fishway section, an upstream pier, an upstream transverse closed retaining wall, an upstream longitudinal closed retaining wall, an upstream fishway support body, a fishway outlet and a fishway water-filled floating body gate. The upstream pier, the upstream transverse closed retaining wall and the upstream longitudinal closed retaining wall are connected with each other, and a hollow cofferdam is formed in an upstream reservoir area; the upstream fishway is arranged in the cofferdam. The application has the beneficial effects that a new arrangement type saves space, saves building materials and shortens construction period; due to the change of the upstream outlet, the downstream inlet position can be arranged more optimally; the fish passing period is increased; automatic scheduling is simple and easy to implement; and the new gate design avoids water leakage.

Description

Technical Field

[0001] This invention relates to a fish passage that utilizes a water-filled floating gate to adapt to changes in upstream water level, and is used in the construction of fish passage facilities for water conservancy and hydropower projects, belonging to the field of water conservancy engineering. Background Technology

[0002] Fish passages are crucial facilities for facilitating fish migration routes. They play an irreplaceable role in fish migration at low-head hydropower projects and are a key component of ecological protection and restoration technologies in water conservancy projects. The "Design Guidelines for Fish Passes in Hydropower Projects (SL 609-2013)" stipulates that multiple fish passage outlets at different locations and elevations should be provided when upstream water levels fluctuate significantly during the main fish migration season. The FAO publication "Fish passes – Design, dimensions and monitoring" recommends that fish passage outlets should ideally be designed as vertical slits, and multiple outlets should be provided if water level fluctuations exceed 1 meter. my country has numerous reservoirs, some of which experience daily water level fluctuations of over 10 meters due to power station regulation. Such significant water level fluctuations pose substantial challenges to the design of fish passage outlets. Conventional designs would require more than 10 fish passage outlets, which is extremely difficult from both a design and management perspective. Exploring design methods to accommodate upstream water level variations has been a focus of research for those skilled in the art.

[0003] The inventors of this invention previously disclosed CN107034861A, "A Hybrid Fishway Capable of Adapting to Large Fluctuations in Upstream Water Levels." However, due to the complex mechanical devices installed in the fishway, especially the bidirectional fish-driving grilles in the fishway lock chamber section, the mechanical processes are extremely complicated. Particularly during floods, a large amount of floating debris accumulates in the fishway lock chamber section, making the mechanical devices difficult to operate and requiring manual cleaning. When there is a significant amount of debris, daily cleaning is necessary, causing considerable inconvenience for maintenance. Although the installation of debris grilles can partially solve this problem, there is still a desire in the art to find a more convenient fishway design that adapts to changes in water level.

[0004] Furthermore, in traditional fishways with multiple outlets, the fishways are arranged along the upstream reservoir, with each fishway outlet spaced 100-200m apart. A fishway with 10 outlets requires 1000-2000m of reservoir bank space to be reserved upstream. The selection and arrangement of such reservoir bank space is quite difficult.

[0005] Existing fishway upstream layout types, such as Figure 1As shown in the diagram, multiple fish passages are designed upstream to accommodate changes in upstream water levels; three passages are shown in the diagram. The water level in the upstream reservoir varies relatively little along the river, so the main rise in the fishway is concentrated downstream. The water level rise caused by the dam is gradually distributed downstream of the fishway. However, the upstream is significantly affected by reservoir water level changes. Therefore, the turning points of the fishway must be located downstream. Downstream, the power station's tailrace channel, the spillway's energy dissipation area, and the lock gate area must also be constructed. Space is extremely limited downstream. To save space downstream while maintaining sufficient length to lower the fishway's inlet elevation, the fishway inlet is often located downstream of the dam. This necessitates adding a fish-blocking structure downstream to prevent fish from swimming all the way down to the dam and being unable to find the fishway entrance.

[0006] Data obtained through long-term observation by the inventors indicates that a large number of fish congregate near the power station and lock, with the downstream fish distribution closer to the lock walls and the power station's tailrace. Therefore, a design is needed to shorten the downstream fishway section, bringing the fish inlet closer to the power station's tailrace channel and the lock gate area. However, the dam's water-retaining elevation is fixed, and the characteristic water levels are selected based on flood control and power generation requirements. Therefore, currently, the upstream opening bottom elevation of the fishway's dam crossing section is near the normal storage level; otherwise, the fishway crossing section would be submerged underwater for extended periods, becoming a submerged conduit. This is a problem that cannot be solved in existing fishway designs.

[0007] The upstream outlet of the fishway is also the inlet for water flow within the fishway. When the upstream water level fluctuates frequently, especially when the fluctuation exceeds the depth of the fishway, gate regulation at the fishway inlet is required. Frequent water level fluctuations pose significant challenges to gate regulation. Regulation based on water level typically requires installing water level sensors and connecting them to the gate's operating mechanism. However, since fishways are usually not involved in flood control or power generation, their gates are typically regulated separately from other gates, often as independent small gates. In this case, using a feedback mechanism between water level sensors and gate operating devices for regulation often increases costs and operational uncertainty. Summary of the Invention

[0008] This invention discloses a fishway that utilizes a water-filled floating gate to adapt to changes in upstream water level. Its purpose is to reduce the spatial arrangement length of the upstream section of the fishway, improve the fishway's adaptability to changes in upstream water level, and enhance the automation of the fishway's inlet scheduling.

[0009] The specific technical solution is as follows:

[0010] A fishway that utilizes a water-filled floating gate to adapt to changes in upstream water level includes: a fishway over dam section, an upstream fishway section, an upstream pier, an upstream transverse enclosed retaining wall, an upstream longitudinal enclosed retaining wall, an upstream fishway support, a fishway outlet, and a fishway water-filled floating gate.

[0011] The upstream piers, the upstream transverse retaining walls, and the upstream longitudinal retaining walls are interconnected with the dam body, forming a hollow cofferdam within the upstream reservoir area.

[0012] The upstream fishway support structure is supported by a column at one end inside the cofferdam and by a beam at the other end on the upstream pier, the upstream transverse closed retaining wall, the upstream longitudinal closed retaining wall, and the dam body.

[0013] The fishway over the dam section connects to the upstream fishway section, which is installed on the upstream fishway support. The upstream fishway section is arranged in a ring along the upstream pier, the upstream transverse retaining wall, the upstream longitudinal retaining wall, and the dam body.

[0014] The overall layout of the upstream fishway section is a turning and descending method. The elevation of each outlet is set according to the residence time of the upstream water level during the scheduling process. The elevation range of each outlet is combined to meet the requirement of covering 85% of the scheduling water level residence time.

[0015] The bottom slope of the upstream fishway section should not exceed the maximum slope required for fish swimming capacity; based on the characteristics of its outlet water level and the distance between the two outlets, the slope can be adjusted between the maximum slope and 0 slope between the two outlets.

[0016] The fishway outlets are multiple, arranged on the upstream fishway section, and pass through the upstream transverse or longitudinal closed retaining wall.

[0017] The bottom elevation of the fishway crossing the dam section is 0.5m below the lower of the 10% low water level during the dry season and the flood control limit water level; a fast gate is installed at the upstream entrance of the fishway crossing the dam section;

[0018] The upstream transverse and longitudinal closed retaining walls mentioned above are dam sections, and their hydrological design standards are the same as those for fishway design.

[0019] The top elevations of the upstream transverse and longitudinal retaining walls are the same as the top elevation of the dam.

[0020] For multi-year regulating reservoirs, the lower of the dry season's 10% low water level and the flood control limit water level is used as the bottom elevation of the fishway outlet.

[0021] For daily regulating reservoirs, the minimum elevation of the fishway outlet is 1m below the flood control limit level.

[0022] The fishway water-filled floating gate consists of multiple gates, which are installed at the fishway outlet of the upstream fishway section.

[0023] The aforementioned upstream piers are either the outer wall of the lock or the outer wall of the guide pier at the power station intake.

[0024] The aforementioned fishway outlet is located outside the upstream transverse or longitudinal enclosed retaining wall; after the water flows through the fishway outlet, its direction does not change, and it flows directly into the upstream fishway section and continues to flow downstream.

[0025] The aforementioned fishway water-filled floating gate includes: a floating gate, a gate hinge, a water seal, an inner baffle, and a bottom semi-barrel-shaped floating body;

[0026] The bottom semi-barrel-shaped float includes a half-cylinder and a closed cylindrical plane; a flat door is connected to the flat door, and a closed door float box is welded to the outer side of the top of the flat door; the float door is fixed on the door hinge and rotates around the door hinge; the water seal is fixed on the inner baffle of the float door.

[0027] The inner baffle is welded to the arc surface of the bottom semi-barrel-shaped float, and an outer baffle is provided on the outside; the inner baffle provides positive pressure for the water seal and limits water seal leakage; the inner baffle works together with the water seal to seal the bottom gap of the gate when the gate is closed.

[0028] When the water level drops to the opening level of the floating gate, the floating gate generates a rotational torque under the gravity of the closed pontoon. At this time, the bottom of the floating gate flips inward and upward, and gets stuck on the outer baffle of the bottom door frame, and the floating gate is in a horizontally open state.

[0029] When the water level rises to the closing level of the floating gate, the floating gate generates a rotational torque under the buoyancy of the closing pontoon. At this time, the bottom of the floating gate reverses downward and outward, and gets stuck in the baffle position inside the bottom door frame, and the floating gate is in a vertically closed state.

[0030] The aforementioned floating body with closed door is equipped with a two-way water pump and a vent pipe, as well as a water pipe;

[0031] The aforementioned bottom semi-barrel-shaped float is connected to the closed-door float box via air and water pipes.

[0032] The aforementioned water pipe is equipped with a gravity hose at its end, which always hangs vertically to the lowest position under the influence of gravity.

[0033] If the gate still cannot be opened when the water level drops to the opening level of the floating gate, the bidirectional water pump will pump water from the bottom semi-bucket-shaped float into the closed gate float box. The water flows into the closed gate float box, increasing the weight and torque of the closed gate float box, thus pushing the gate open.

[0034] When the water level rises to the closing level of the floating gate, if the gate still cannot be closed, the bidirectional water pump will pump the water in the closed gate float box into the bottom semi-bucket-shaped float. The combined effect of the water weight of the bottom semi-bucket-shaped float and the buoyancy of the closed gate float box makes the gate vertical, further pushing the gate to close.

[0035] The bottom angle of the aforementioned closed-gate pontoon, closest to the gate, is an acute angle, with a range of 52°. <A<90°。

[0036] When multiple gates are located at different elevations, different water levels will open different gates of the fishway's water-filling floats, allowing water at different elevations to flow into the fishway.

[0037] The beneficial effects of this invention are as follows:

[0038] 1. This invention proposes a fishway with a new upstream arrangement, which reduces the use of upstream space;

[0039] 2. The method for controlling the fishway outlet using a floating gate proposed in this invention greatly reduces the difficulty of gate scheduling; it enables the gate at the corresponding height of the fishway to open automatically when the water level is certain, and the gate underwater to close, ensuring the stability and continuity of water intake and fish output in the fishway.

[0040] 3. The design of the floating gate provides the function of automatically opening and closing the gate at appropriate water levels. At the same time, the design of its closing float box improves the opening and closing force of the gate. Combined with the water seal design, it effectively avoids water leakage when the gate is closed, which would cause water flow disorder in the downstream fishway.

[0041] Instruction manual illustrations

[0042] Figure 1 Schematic diagram of fishway layout in existing technology;

[0043] Figure 2 A schematic diagram of the fishway layout proposed in this invention;

[0044] Figure 3 The schematic diagram of the upstream fishway layout of this invention is as follows: Figure 2 A magnified view of the area at position M in the middle;

[0045] Figure 4 AA' sectional view of the present invention;

[0046] Figure 5 This is a cross-sectional view of BB' of the present invention;

[0047] Figure 6 yes Figure 3 A magnified view of N in the middle;

[0048] Figure 7 A partial enlarged view of the opening and closing state of the gate when fish cannot pass through the high-water fish passage of the present invention, P.

[0049] Figure 8 A magnified view of P, showing the opening and closing state of the gate at the highest inlet for fish passage in this invention.

[0050] Figure 9 The diagram shows the opening and closing state of the gate for fish passage through the second highest inlet in this invention, and a partial enlarged view of P.

[0051] Figure 10 A magnified view of P, showing the opening and closing state of the gate through which fish pass via the lowest inlet in this invention.

[0052] Figure 11 A cross-sectional schematic diagram of the fishway self-opening and closing gate in this invention;

[0053] Figure 12 A cross-sectional schematic diagram of the fishway self-opening and closing gate in the tilted state in this invention, where S is the inner water surface;

[0054] Figure 13 A schematic diagram of the bottom angle A position of the closed-door float box on the side close to the gate in this invention.

[0055] Among them, 1 is the dam section, 2 is the power station section, 3 is the lock, 4 is the fishway, 41 is the upstream fishway section in the prior art, 42 is the upstream fishway section of the present invention, SW is the water level, and S is the inner water surface. Detailed Implementation

[0056] The present invention will now be further described with reference to the accompanying drawings.

[0057] Example 1

[0058] A fishway with a turning arrangement and utilizing a water-filled buoy to adapt to changes in upstream water level includes: a fishway over dam section 41, an upstream fishway section 42, an upstream pier 43, an upstream transverse enclosed retaining wall 44, an upstream longitudinal enclosed retaining wall 45, an upstream fishway support 46, a fishway outlet 47, and a fishway water-filled buoy gate.

[0059] The upstream pier 43, the upstream transverse retaining wall 44, and the upstream longitudinal retaining wall 45 are interconnected with the dam body, forming a hollow cofferdam in the upstream reservoir area.

[0060] The upstream fishway support 46 is supported by a column at one end inside the cofferdam, and by a beam at the other end on the upstream pier 43, the upstream transverse closed retaining wall 44, the upstream longitudinal closed retaining wall 45, and the dam body.

[0061] The fishway section 41 that crosses the dam connects to the upstream fishway section 42, which is installed on the upstream fishway support 46. The upstream fishway section 42 is arranged in a ring along the upstream pier 43, the upstream transverse retaining wall 44, the upstream longitudinal retaining wall 45, and the dam body.

[0062] The overall layout of the upstream fishway section 42 is a turning and descending method. The elevation of each outlet is set according to the residence time of the upstream water level during the scheduling process. The elevation range of each outlet is combined to meet the requirement of covering 85% of the scheduling water level residence time.

[0063] During the fish migration season, the reservoir scheduling plan shows that the water level will remain between 34.5 and 37.8 meters for 100% of the entire season.

[0064] Therefore, in this embodiment, the lowest outlet bottom elevation is 33.7m, the highest outlet bottom elevation is 36.8m, and the middle outlet bottom elevation is 35.21m; the middle outlet bottom elevations are the average between the highest and lowest.

[0065] The maximum water depth of the fishway is 1.59m. The water depth range of the fishway is 0.5 to 1.59m.

[0066] The bottom slope design of upstream fishway section 42 shall not exceed the maximum slope required to meet the swimming capacity of fish;

[0067] In this embodiment, the swimming ability of the target fish is 1.1 m / s, and the bottom slope design value is 1V:200H; the bottom slope of the upstream fishway is adjusted between 0 and 1:200.

[0068] There are three fishway outlets 47, which are located on the upstream fishway section 42 and the upstream longitudinal closed retaining wall 45.

[0069] The bottom elevation of the upstream side of the fishway over the dam section 41 is 0.5m lower than the bottom elevation of the fishway outlet; a fast gate 411 is installed on the upstream side of the fishway over the dam section.

[0070] The upstream transverse closed retaining wall 44 and the upstream longitudinal closed retaining wall 45 mentioned above are water-retaining dam sections. Their hydrological design standards are the same as those of the fishway, both designed for a 100-year return period and checked for a 1000-year return period.

[0071] The top elevations of the upstream transverse retaining wall 44 and the upstream longitudinal retaining wall 45 are the same as the top elevation of the dam.

[0072] In this embodiment, the dry season 10% low water level is 34.2m and the flood limit water level is 34.5m. Therefore, the lowest elevation of the fishway outlet 47 in this embodiment is 34.2-0.5=33.7m.

[0073] Multiple fishway water-filled floating gates 48 are installed on the fishway outlet 47 of the upstream fishway section 42.

[0074] The aforementioned upstream pier 43 is the outer wall of the guide pier at the power station's inlet.

[0075] The aforementioned fishway outlet is located on the upstream transverse closed retaining wall or the upstream longitudinal closed retaining wall; after the water enters the fishway outlet 47, its direction does not change, and it flows directly into the upstream fishway section 42 and continues to flow downstream.

[0076] The aforementioned fishway water-filled floating gate includes: a floating gate 51, a gate hinge 52, a water seal 53, an inner baffle 54, and a bottom semi-barrel-shaped floating body 55;

[0077] The bottom semi-barrel-shaped float 55 includes a half-barrel and a closed cylindrical plane; a flat door is connected to the flat plane, and a closed door float 59 is welded to the outer side of the top of the flat door; the float door 51 is fixed on the door hinge 52 and rotates around the door hinge 52; the water seal 53 is fixed on the inner baffle 54 of the float door 51.

[0078] The inner baffle 54 is welded to the arc surface of the bottom semi-barrel-shaped float 55, and an outer baffle 56 is provided on the outside. The inner baffle 54 provides positive pressure to the water seal 53 and restricts water leakage from the water seal 53. The inner baffle 54 and the water seal 53 work together to seal the bottom gap of the gate when the gate is closed.

[0079] When the water level drops to the opening level of the floating gate 51, the floating gate 51 generates a rotational torque under the gravity of the closed floating box 59. At this time, the bottom of the floating gate 51 flips inward and upward, and gets stuck in the position of the outer baffle 56 of the bottom door frame, and the floating gate is in a horizontally open state.

[0080] When the water level rises to the closing level of the floating gate 51, the floating gate generates a rotational torque under the buoyancy of the closing buoy 59. At this time, the bottom of the floating gate reverses downward and outward, and gets stuck in the position of the baffle 54 inside the bottom door frame, and the floating gate is in a vertically closed state.

[0081] The aforementioned floating body door pontoon 59 is equipped with a bidirectional water pump 591, an air vent pipe 592, and a water vent pipe 593.

[0082] The aforementioned bottom semi-barrel-shaped float 55 is interconnected with the closed-door float box 59 via a vent pipe 592 and a water pipe 593.

[0083] The water pipe 593 is equipped with a gravity hose 594 at its end. The gravity hose 594 always hangs vertically to the lowest position under the action of gravity.

[0084] If the gate still cannot be opened when the water level drops to the opening level of the floating gate, the bidirectional water pump 57 pumps water from the bottom semi-barrel-shaped float 55 into the closed gate float box 59. The water flows into the closed gate float box 59, increasing the weight and torque of the closed gate float box 59, thus pushing the gate open.

[0085] When the water level rises to the closing level of the floating gate, if the gate still cannot be closed, the bidirectional pump 57 pumps the water in the closed gate float 59 into the bottom semi-bucket float 55. The combined effect of the water weight of the bottom semi-bucket float 55 and the buoyancy of the closed gate float 59 makes the gate vertical, further pushing the gate to close.

[0086] The bottom angle of the aforementioned closed-gate pontoon 59, which is close to the gate, is an acute angle, with an angle range of 52°. <A<90°。

[0087] When multiple gates are located at different elevations, different water levels will open different gates of the fishway's water-filling floats, allowing water at different elevations to flow into the fishway.

Claims

1. A fishway that utilizes a water-filled floating gate to adapt to changes in upstream water level, characterized in that: include: Fishway over dam section, upstream fishway section, upstream pier, upstream transverse closed retaining wall, upstream longitudinal closed retaining wall, upstream fishway support structure, fishway outlet, fishway water-filled floating gate. The upstream piers, the upstream transverse retaining walls, and the upstream longitudinal retaining walls are interconnected with the dam body, forming a hollow cofferdam within the upstream reservoir area. The upstream fishway support structure is supported by a column at one end inside the cofferdam and by a beam at the other end on the upstream pier, the upstream transverse closed retaining wall, the upstream longitudinal closed retaining wall, and the dam body. The fishway over the dam section connects to the upstream fishway section, which is installed on the upstream fishway support. The upstream fishway section is arranged in a ring along the upstream pier, the upstream transverse retaining wall, the upstream longitudinal retaining wall, and the dam body. The aforementioned fishway water-filled floating gate includes: a flat gate, a gate hinge, a water seal, an inner baffle, and a bottom semi-barrel-shaped float; the bottom semi-barrel-shaped float includes half a cylindrical barrel and a closed cylindrical plane; the flat gate is connected to the plane, and a closed gate float box is welded to the outer top of the flat gate; the flat gate is fixed on the gate hinge and rotates with the gate hinge as the rotation axis; the water seal is fixed on the inner baffle. The inner baffle is welded to at least the middle position of the arc surface of the bottom semi-barrel-shaped float, and the inner baffle extends along the length of the bottom semi-barrel-shaped float; the inner baffle provides positive pressure for the water seal and limits water seal leakage; the inner baffle works together with the water seal to seal the bottom gap of the gate when the gate is closed; an outer baffle is provided on the outer side of the closed cylinder of the bottom semi-barrel-shaped float.

2. A fishway according to claim 1, which utilizes a water-filled floating gate to adapt to changes in upstream water level, is characterized in that: When the water level drops to the opening level of the fishway filling floating gate, the fishway filling floating gate generates a rotational torque under the gravity of the closed buoyant box. At this time, the bottom of the fishway filling floating gate flips inward and upward, the flat gate is in a horizontal state, and the outer baffle is in a vertical state. The outer baffle is blocked by the edge of the gate bottom plate, so the fishway filling floating gate is in a horizontal open state. When the water level rises to the closing level of the fishway filling floating gate, the fishway filling floating gate generates a rotational torque under the buoyancy of the closed buoyant box. At this time, the bottom of the fishway filling floating gate flips downward and outward, the top of the flat gate is blocked by the edge of the gate top plate, and the fishway filling floating gate is in a vertical closed state.

3. A fishway according to claim 1, which utilizes a water-filled floating gate to adapt to changes in upstream water level, is characterized in that: The closed-door float box is equipped with a bidirectional water pump, an air vent pipe, and a water vent pipe; the bottom semi-barrel-shaped float is connected to the closed-door float box via the air vent pipe and the water vent pipe; a gravity hose is installed at the end of the water vent pipe, and the gravity hose always hangs vertically to the lowest position under the action of gravity.

4. A fishway according to claim 1, which utilizes a water-filled floating gate to adapt to changes in upstream water level, is characterized in that: If the gate still cannot open when the water level drops to the opening level of the fishway filling float gate, the bidirectional water pump will pump water from the bottom semi-barrel-shaped float to the closed float box. The water flowing into the closed float box increases its weight and torque, pushing the fishway filling float gate open. When the water level rises to the closing level of the fishway filling float gate, if the gate still cannot close, the bidirectional water pump will pump water from the closed float box into the bottom semi-barrel-shaped float. The combined effect of the water weight of the bottom semi-barrel-shaped float and the buoyancy of the closed float box makes the fishway filling float gate vertical, further pushing it to close.

5. A fishway according to claim 1, which utilizes a water-filled floating gate to adapt to changes in upstream water level, characterized in that: The bottom angle A of the aforementioned closed-gate pontoon, closest to the gate, is an acute angle, with a range of 52°. <A<90°。

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