A fish gathering system using power generation tail water

Abstract

This invention discloses a fish-attracting system utilizing power generation tailwater for fish collection, comprising an inlet bar, an inlet channel, an inlet gate, an outlet fish-blocking bar, a fish-attracting pond, a fish-attracting box, a water supply pipe, an inlet fish-blocking bar, an inlet gate, and a culvert-type fish-attracting channel. The inlet bar is installed at the inlet and has multiple parallel horizontal inlet channels running vertically. The inlet channel is downstream of the inlet bar, the inlet gate is downstream of the inlet channel, the fish-attracting pond is downstream of the inlet gate, and the fish-attracting box is arranged within the fish-attracting pond. The outlet fish-blocking bar is located on the side of the fish-attracting pond near the inlet gate, and the inlet fish-blocking bar is located at the downstream end of the fish-attracting pond. The culvert-type fish-attracting channel is located downstream of the fish-attracting pond and has a culvert-type fish inlet. The water supply pipe is connected to the side wall of the fish-attracting pond for replenishing water to the pond. This invention can introduce an appropriate amount of power generation tailwater into the fish-attracting system under different water level conditions, creating a suitable fish-attracting flow rate.

Description

Technical Field

[0001] This invention belongs to the fields of ecological water conservancy engineering and environmental protection engineering, and specifically relates to a fish collection system that uses power generation tailwater for fish collection. Background Technology

[0002] While the construction of high dams and large reservoirs for hydropower stations benefits the national economy and people's livelihoods, it also negatively impacts river connectivity, damaging the structure and integrity of the entire river ecosystem. Fish passage facilities, serving as connecting channels between the upstream and downstream of dammed rivers, aim to assist fish migration and promote the exchange of matter, energy, and genes, minimizing habitat fragmentation caused by hydropower station construction. Fish attraction facilities are crucial to the success of fish passage facilities, and the key to successful fish attraction lies in water flow conditions. Water flow conditions mainly include flow velocity and water depth, generally selecting flow velocities preferred by fish and suitable water depths. Currently, three common methods are used to create these conditions: pump station replenishment, reservoir water diversion, and utilization of power plant tailwater. Utilizing power plant tailwater to create flow conditions is a low-cost and highly effective method. Fish attraction facilities using power plant tailwater are typically located near the tailwater, an area where fish congregate; therefore, using tailwater to create flow conditions for fish attraction is an exceptionally efficient method.

[0003] Existing fish collection devices utilizing tailwater from power generation plants all employ fixed or adjustable inlets. However, water levels vary significantly under different power generation conditions, and since tailwater is typically drawn from a single tunnel, a fixed inlet results in a relatively constant flow rate. At high water levels, the flow velocity in the fish collection system and its inlet is low, potentially below the velocity sensed by fish; at low water levels, the flow velocity is high, potentially exceeding the speed at which fish swim. Adjusting the size of the inlet requires metal structures, which present significant challenges in design, manufacturing, installation, operation, and maintenance, and also increase investment. In power plants with high tailwater flow velocities, adjusting the inlet using metal structures is difficult or poses safety hazards. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a fish collection system that utilizes the tailwater from power generation for fish collection. Through the design of the inlet and the culvert-type fish inlet, it is possible to create an attractive flow rate for the fish collection system under different water level conditions, while reducing the amount of water to be added.

[0005] The objective of this invention is achieved through the following technical solution: A fish collection system that uses tailwater from power generation for fish collection includes an inlet bar screen, an inlet channel, an inlet gate, an outlet fish barrier screen, a fish collection pond, a fish collection box, a water supply pipe, an inlet fish barrier screen, an inlet gate, and a culvert-type fish inlet channel. The water inlet grille is installed at the water inlet of the fish collection system, and the water inlet grille has multiple parallel horizontal water inlet channels along the vertical direction; The water intake channel is located downstream of the water intake grille and is used to direct the tailwater from the power generation into the fish collection pond after adjusting its direction. The width of the water intake channel gradually increases along the direction of water flow. The inlet gate is located downstream of the inlet channel and is used to open or close the channel through which the tailwater from the power generation enters the fish collection pond. The fish collection pond is located downstream of the inlet gate, and the fish collection box is arranged inside the fish collection pond; The outlet fish barrier is installed on the side of the fish collection pool near the inlet gate, and the inlet fish barrier is located at the downstream end of the fish collection pool. Both are used to prevent fish that have entered the fish collection pool from swimming out. The culvert-type fish inlet channel is located downstream of the fish collection pond, the fish inlet gate is installed inside the culvert-type fish inlet channel, and the culvert-type fish inlet channel is provided with a culvert-type fish inlet. The water supply pipe is connected to the side wall of the fish collection pond and is used to supply water to the fish collection pond.

[0006] Furthermore, the height of the inlet grille is set between the lowest and highest water levels in the downstream river channel.

[0007] Furthermore, the top elevation of the culvert-type fish inlet is below the lowest water level in the downstream river channel.

[0008] Furthermore, a sonar sidewall groove is provided on the sidewall of the fish collection pond, and a sonar is installed thereon for observing the number of fish in the fish collection pond.

[0009] Furthermore, there are two or more culvert-type fish inlet channels, and adjacent culvert-type fish inlet channels are separated by flow dividers.

[0010] The beneficial effects of this invention are as follows: 1. This invention uses the tailwater from power generation to attract fish, and at the same time uses an inlet grille to guide the water to the fish collection system. This ensures that when the water level in the river changes, the flow velocity at the inlet of the fish collection system is within the range preferred by the fish, thus reducing the range of changes.

[0011] 2. The present invention sets up a culvert-type fish inlet channel and a culvert-type fish inlet, fixes the required flow rate of the fish collection system, reduces the water replenishment flow rate, and at the same time reduces the range of variation in the flow velocity at the fish inlet.

[0012] 3. The present invention installs a sonar on the side wall of the fish collection pond to observe the number of fish in the fish collection pond in order to determine whether to raise the fish collection box.

[0013] 4. This invention uses a water supply pipe for water replenishment, which can solve the problem of attracting fish when there is no power generation. At the same time, it uses a culvert-type fish inlet channel, which can achieve a suitable fish-attracting flow rate with less water replenishment flow compared to open channels. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the plan layout of a fish collection system that utilizes the tailwater from power generation for fish collection, according to an embodiment of the present invention.

[0015] Figure 2 This is a longitudinal section view of a fish collection system that utilizes the tailwater from power generation for fish collection, according to an embodiment of the present invention.

[0016] Figure 3 This is a schematic diagram showing the position of the water inlet grille 1 in an embodiment of the present invention.

[0017] Figure 4 This is a perspective view of a fish collection system that utilizes the tailwater from a power generation plant for fish collection, according to an embodiment of the present invention.

[0018] Figure 5 This is a cloud map showing the internal flow velocity distribution of the fish collection system under the operating condition of a single generator generating water level of 1914.08m when using the existing open channel water intake type A.

[0019] Figure 6 This is a cloud map showing the internal flow velocity distribution of the fish collection system under the condition of four generators generating electricity at a water level of 1919.13m when the water inlet is of type B in an open channel.

[0020] Figure 7 This is a cloud map showing the internal flow velocity distribution of a fish collection system with a water level of 1914.08m and an inlet bar.

[0021] Figure 8 This is a cloud map showing the internal flow velocity distribution of the fish collection system under the condition of four generators operating at a water level of 1919.13m when using an inlet grille.

[0022] Among them, the following structures are included: 1. Inlet bar screen; 2. Horizontal inlet channel; 3. Inlet open channel; 4. Inlet gate slot; 5. Inlet gate; 6. Outlet fish barrier screen; 7. Fish collection pond; 8. Fish collection box; 9. Water supply pipe; 10. Sonar side wall slot; 11. Inlet fish barrier screen; 12. Culvert superstructure; 13. Flow divider; 14. No. 1 fish inlet gate slot; 15. No. 1 fish inlet gate slot; 16. No. 2 fish inlet gate; 17. No. 1 culvert-type fish inlet channel; 18. No. 2 culvert-type fish inlet channel; 19. No. 1 culvert-type fish inlet; 20. No. 2 culvert-type fish inlet; 21. River water surface line; 22. Power generation tailwater diversion pier; 23. Power generation tailwater tunnel outlet sidewall; 24. Power generation tailwater outlet. Detailed Implementation

[0023] The present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. The purpose and effects of the present invention will become clearer. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0024] The basic concept of this invention is to introduce the wastewater from power generation into a fish collection facility through an inlet grille structure. The inlet grille primarily reduces the water flow rate and the internal flow velocity of the fish collection facility during low water levels. During high water levels, the wastewater is introduced into the fish collection facility not only through the inlet grille but also from the top of the grille, increasing the water flow rate and the internal flow velocity. The fish inlet is a culvert type to reduce the makeup water flow rate and minimize the range of velocity variations at the inlet.

[0025] like Figures 1-4 As shown, the fish collection system using the tailwater of the power generation is located upstream or downstream of the tailwater outlet 25. The tailwater diversion pier 23 and the side wall 24 of the tailwater tunnel outlet are flush and do not affect the outflow of the tailwater. An opening is provided between the tailwater diversion pier 23 and the side wall 24 of the tailwater tunnel outlet as the inlet of the system using the tailwater of the power generation for fish collection.

[0026] The system for fish collection using the tailwater from power generation in this embodiment includes an inlet grille 1, an inlet open channel 3, an inlet gate slot 4, an inlet gate 5, an outlet fish barrier grille 6, a fish collection pond 7, a fish collection box 8, a water supply pipe 9, an inlet fish barrier grille 11, a culvert superstructure 12, a flow divider 13, a gate slot 14 for fish inlet 1, a gate slot 15 for fish inlet 2, a gate 16 for fish inlet 1, a gate 17 for fish inlet 2, a culvert-type fish inlet channel 18, a culvert-type fish inlet channel 19, a culvert-type fish inlet 20, and a culvert-type fish inlet 21.

[0027] Among them, the inlet grille 1 is installed on the inlet, such as Figure 3 As shown, multiple parallel horizontal water inlet channels 2 are opened vertically on the water inlet grille 1. The height of the horizontal water inlet channels 2 is determined according to the required flow rate of the fish collection system. The height of the water inlet grille 1 should be set between the lowest and highest water levels in the downstream river channel.

[0028] The intake channel 3 is located downstream of the intake screen 1. It is an open channel with a certain curvature, used to redirect the power generation tailwater into the fish collection pond 7. The width of the intake channel 3 gradually increases along the water flow direction. The intake gate 5 and the intake gate slot 4 are located downstream of the intake channel 3, with the intake gate 5 installed within the intake gate slot 4, used to open or close the channel for the power generation tailwater to enter the fish collection pond 7. The fish collection pond 7 is located downstream of the intake gate 5, and the fish collection box 8 is arranged within the fish collection pond 7. Figure 2As shown. The outlet fish barrier 6 is located on the side of the fish collection pool 7 near the inlet gate 5, and the inlet fish barrier 11 is located at the downstream end of the fish collection pool 7, both used to prevent fish entering the fish collection pool 7 from swimming out. The culvert superstructure 12, the No. 1 culvert-type fish inlet channel 18, the No. 2 culvert-type fish inlet channel 19, and the flow divider 13 are all located downstream of the fish collection pool 7. The flow divider 13 separates the No. 1 culvert-type fish inlet channel 18 and the No. 2 culvert-type fish inlet channel 19. The No. 1 culvert-type fish inlet channel 18 is equipped with the No. 1 inlet gate slot 14 and the No. 1 inlet gate 16, and the No. 1 culvert-type fish inlet 20 is located on the downstream side; the No. 2 culvert-type fish inlet channel 19 is equipped with the No. 2 inlet gate slot 15 and the No. 2 inlet gate 17, and the No. 2 culvert-type fish inlet 21 is located on the downstream side. If necessary, only one fish inlet channel may be set up downstream of the fish collection pond 7, that is, only one of the No. 1 culvert-type fish inlet channel 18 and the No. 2 culvert-type fish inlet channel 19 may be set up.

[0029] The imported fish barrier 11 is a vertically liftable barrier. When fish need to be introduced into the fish collection pond 7, the imported fish barrier 11 is lifted above the No. 1 culvert-type fish inlet channel 18 and the No. 2 culvert-type fish inlet channel 19. Before the fish collection box 8 needs to be lifted to collect fish, the imported fish barrier 11 is lowered to the bottom.

[0030] Water supply pipe 9 is connected to the side wall of fish collection pond 7 and is used to supply water to fish collection pond 7.

[0031] In addition, a sonar sidewall groove 10 is provided on the inner sidewall of the fish collection pond 7 for installing a sonar to observe the number of fish in the fish collection pond 7.

[0032] The working principle of the fish collection system that utilizes the tailwater from power generation in this embodiment is as follows: When water flows out of the tailwater outlet 25, the inlet gate 5, fish inlet gate 16, and fish inlet gate 17 are opened. The water flows into the fish collection system through the inlet grille 1 and the inlet channel 3, and flows out through the fish collection pond 7, the culvert-type fish inlet channel 18, the culvert-type fish inlet channel 19, the culvert-type fish inlet 20, and the culvert-type fish inlet 21. The attracted fish enter the culvert-type fish inlet channel 18 and the culvert-type fish inlet channel 19 through the culvert-type fish inlet 20 and the culvert-type fish inlet 21, and then enter the fish collection pond 7. The number of fish in the fish collection pond 7 is observed through the sonar installed in the sonar sidewall groove 10. When the number reaches a certain scale, the inlet fish barrier 11 is closed and the fish collection box 8 is raised to collect the fish. When there is no water flow from the tailwater outlet 25, close the inlet gate 5 and the No. 1 fish inlet gate 16, open the No. 2 fish inlet gate 17, and open the water supply pipe 9 to replenish the fish collection pond 7. The water flows out from the No. 2 culvert-type fish inlet channel 19, the No. 2 culvert-type fish inlet 21, etc. The attracted fish enter the No. 2 culvert-type fish inlet channel 19 through the No. 2 culvert-type fish inlet 21, and then enter the fish collection pond 7. The number of fish in the fish collection pond 7 is still observed through the sonar installed in the sonar side wall groove 10. When the number reaches a certain scale, close the inlet fish barrier 11 and raise the fish collection box 8 to collect the fish.

[0033] Since hydropower stations typically have multiple generating units, the water level in the river can vary considerably depending on the number of generating units.

[0034] To ensure that the water flow velocity in culvert-type fish inlets 18, 19, 20, and 21 is within the range preferred by fish, the flow rate of the fish collection system needs to be adjusted according to the water level fluctuations within the river channel. When the water level is low and the water surface line 22 does not exceed the height of the inlet grille 1, water is drawn in through the inlet grille opening 2 inside the inlet grille 1. Due to the low water surface line 22, to ensure that the flow velocity in culvert-type fish inlets 18, 19, 20, and 21 does not exceed the preferred flow velocity of fish, the entire fish collection system requires a low flow rate. Introducing the flow rate through the inlet grille opening 2 satisfies the low flow rate requirement. When the water level in the river channel is high, and the water surface line 22 exceeds the height of the inlet grille 1, the water not only enters from the inlet grille opening 2 inside the inlet grille 1, but also flows in from the top of the inlet grille 1, increasing the inlet flow rate.

[0035] The height h1 of the inlet screen 1 should ideally be between the lowest and highest water levels in the downstream river channel. The top elevation h2 of the No. 1 culvert-type fish inlet channel 18 and the No. 2 culvert-type fish inlet channel 19 should be below the lowest water level in the downstream river channel. To ensure that the water flow velocity at the No. 1 culvert-type fish inlet 20 and the No. 2 culvert-type fish inlet 21 is within the range preferred by fish, the required flow rate of the fish collection system can be simply calculated using the following formula: Flow rate Q = w × h2 × v, where w represents the width of the culvert-type channel, h2 represents the height of the culvert-type channel, and v represents the water flow velocity within the culvert-type channel. The water flow velocity should be determined based on the preferred flow velocity of fish, and is generally taken as 0.5~1.0 m / s. The number and height of the horizontal inlet channels 2 of the inlet screen 1 can be adjusted according to the flow rate, which can be determined based on numerical simulation calculations or physical models.

[0036] The effectiveness of the fish collection system of the present invention will be illustrated below through a specific embodiment.

[0037] Existing fish collection systems typically use open channels as their water inlets. For example... Figure 5 The image shows the flow velocity distribution cloud map inside the fish collection system under the operating condition of one generator at a water level of 1914.08m, with an open channel intake type A. Figure 5 The left image is a surface velocity cloud map of the underwater surface at a depth of 2 meters. Figure 5 The right figure in the figure is a longitudinal profile velocity cloud map of the left channel. It can be seen from the figure that when the open channel inlet type A is in operation with one machine, that is, when the tailwater of the downstream river is low, the internal flow velocity of the fish collection system is too high, which exceeds the fish's ability to withstand the flow. Figure 6 The image shows the flow velocity distribution cloud map inside the fish collection system under the operating condition of four generators at a water level of 1919.13m when the water intake is of type B in an open channel. Figure 6 The left image is a surface velocity cloud map of the underwater surface at a depth of 2 meters. Figure 6 The right figure shows the velocity contour map of the longitudinal section of the left channel. It can be seen from the figure that, under the condition of four turbines operating (i.e., when the downstream tailwater is high), the internal flow velocity of the fish collection system in open channel inlet type B is relatively low, making it difficult to attract fish into the system. Therefore, neither type A nor type B of open channel inlet can guarantee that the internal flow velocity of the fish collection system remains within a suitable range for fish under different water levels in the river.

[0038] And Figure 5 and Figure 6 The open channel inlets were all replaced with the inlet grilles of this invention, and the results are as follows: Figure 7 and Figure 8 As shown, Figure 7 This is a cloud map showing the internal flow velocity distribution of a fish collection system with a single generator operating at a water level of 1914.08m, using an inlet bar screen. Figure 8 This is a cloud map showing the internal flow velocity distribution of the fish collection system under the condition of four generators operating at a water level of 1919.13m when using an inlet bar screen. Figure 7 and Figure 8 As can be seen, whether it is a single machine or four machines using the inlet grille, the internal flow velocity of the fish collection system can be basically maintained within the range of flow velocity suitable for fish.

[0039] It will be understood by those skilled in the art that the above descriptions are merely preferred examples of the invention and are not intended to limit the invention. Although the invention has been described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. All modifications and equivalent substitutions made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A fish collection system that utilizes tailwater from power generation for fish collection, characterized in that, It includes inlet bar screens, inlet open channels, inlet gates, outlet fish barriers, fish collection ponds, fish collection boxes, water supply pipes, inlet fish barriers, inlet gates, and culvert-type fish inlet channels; The water inlet grille is installed at the water inlet of the fish collection system, and the water inlet grille has multiple parallel horizontal water inlet channels along the vertical direction; The water intake channel is located downstream of the water intake grille and is used to direct the tailwater from the power generation into the fish collection pond after adjusting its direction. The width of the water intake channel gradually increases along the direction of water flow. The inlet gate is located downstream of the inlet channel and is used to open or close the channel through which the tailwater from the power generation enters the fish collection pond. The fish collection pond is located downstream of the inlet gate, and the fish collection box is arranged inside the fish collection pond; The outlet fish barrier is installed on the side of the fish collection pool near the inlet gate, and the inlet fish barrier is located at the downstream end of the fish collection pool. Both are used to prevent fish that have entered the fish collection pool from swimming out. The culvert-type fish inlet channel is located downstream of the fish collection pond, the fish inlet gate is installed inside the culvert-type fish inlet channel, and the culvert-type fish inlet channel is provided with a culvert-type fish inlet. The water supply pipe is connected to the side wall of the fish collection pond and is used to supply water to the fish collection pond.

2. The fish collection system for using power generation tailwater for fish collection according to claim 1, characterized in that, The height of the inlet grille is set between the lowest and highest water levels in the downstream river channel.

3. The fish collection system for using power generation tailwater for fish collection according to claim 1, characterized in that, The top elevation of the culvert-type fish inlet is below the lowest water level in the downstream river channel.

4. The fish collection system for using power generation tailwater for fish collection according to claim 1, characterized in that, The side wall of the fish collection pond is provided with a sonar side wall slot and a sonar is installed thereon for observing the number of fish in the fish collection pond.

5. The fish collection system for using power generation tailwater for fish collection according to claim 1, characterized in that, There are two or more culvert-type fish inlet channels, and adjacent culvert-type fish inlet channels are separated by flow dividers.

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