A fishway inlet water level amplitude adaptive along-path shunting system

Abstract

This invention provides a flow diversion system adaptable to variations in the inlet water level of a fishway, comprising a fishway, a water level and velocity monitoring device, a diversion inlet device, branch diversion pipes and valves, a main diversion pipe and a main valve. The diversion inlet device is located at the bottom of the pool chamber or resting area downstream of the fishway and is connected to the branch diversion pipes. Each branch diversion pipe has its flow rate controlled by a valve at its end. All branch diversion pipes converge into a main diversion pipe extending along the sidewall of the fishway, with a main valve at its end. The water level and velocity monitoring device is arranged in the pool chamber to control the opening and closing of the valves to regulate the diversion flow rate. The fishway includes a fishway outlet, a fishway inlet, a pool chamber, and a resting area. The pool chamber is formed by staggered wide and narrow partitions, with vertical slits between the wide and narrow partitions serving as an upstream flow channel for fish. This invention, through flow diversion along the fishway, reduces the water level difference in the inlet section of the pool chamber and the flow velocity in the vertical slits, thereby improving the adaptability of the fishway inlet water level to variations.

Description

Technical Field

[0001] This utility model relates to the field of water conservancy and hydropower ecological protection technology, and in particular to a diversion system along the fishway that adapts to the fluctuation of the inlet water level. Background Technology

[0002] Whether the inlet water flow conditions are suitable for fish to find and enter is a core factor affecting the fish passage's effectiveness. However, the range of water level variations that a single inlet can adapt to is limited, and the inlet water flow conditions are significantly affected by changes in the downstream water level. When the downstream water level is lower than the inlet's adaptable water level, the water surface line will drop sharply at the inlet section, causing increased flow velocity or even a drop in water level, which affects fish swimming upstream. When the downstream water level rises, the inlet depth increases accordingly, and the flow velocity decreases significantly, making it difficult for fish to sense the passage and significantly reducing the fish-attracting ability of the fishway inlet.

[0003] In my country, it is common for the inlet water level of fish passages to fluctuate beyond the passage's adaptability. In-situ observations of existing fish passages have revealed that when the downstream water level fluctuates by more than two meters, the inlet hydraulic conditions change significantly, which in turn affects the fish attraction and fish entry effects.

[0004] Currently, there are two main methods to improve the ability of fishway inlets to adapt to water level changes: setting up multiple inlets and setting up a water replenishment system. (1) Setting up multiple inlets is the most common solution. For example, in order to adapt to water level changes, the Jinsha Hydropower Station fishway has 3 inlets, and the Xiaonanhai project plans to set up as many as 6 inlets when planning the fish passage scheme. Although setting up multiple inlets can expand the range of water levels that can be adapted, there are also disadvantages: ① It increases the amount of engineering work for gates and opening and closing equipment, and increases the difficulty of layout; ② When switching inlets due to water level changes, upstream fish must change their migration route and find new inlets. If it cannot be guaranteed that all inlets are in densely distributed fish areas, their fish-attracting effect will be greatly reduced; ③ For projects with frequent and large water level changes, especially daily regulating reservoirs, multiple inlets need to be frequently switched and dispatched. The process is cumbersome and time-consuming, which not only affects the passage of fish, but also increases the difficulty of operation and management. (2) Setting up a water replenishment system is another measure to adapt to changes in downstream water level. Many fishways, such as Baihe and Zangmu, have water replenishment systems installed at their inlet sections. When the water level is high, water is added to the fishway to increase the inlet flow velocity. Although the water replenishment system can alleviate the problem of reduced flow velocity caused by rising water level to a certain extent, its disadvantages are that the system is complex, the flow velocity is difficult to control, the water consumption is large, and the operating cost is high.

[0005] In other countries, fishways are mostly built on small and medium-sized rivers where water level fluctuations are relatively small, and the impact of water level changes on fish passage is not a significant issue. Even on large rivers like the Columbia River in the United States, multiple fishways or various fish passage facilities are generally installed, making it relatively easy to adapt to water level changes. Therefore, the experience available for reference abroad is relatively limited.

[0006] When the fishway outlet is at the designed water depth, but the fishway inlet water depth is less than the designed water depth, the water depth variation in the fishway is mainly concentrated in a portion of the inlet section, resulting in a large water level difference between the sections and a vertical slit flow velocity greater than the designed flow velocity of the fishway. Based on the above research, improving the adaptability of the fishway inlet water level variation is a key technical issue for improving the efficiency of fish passage through the fishway, and can also increase the success rate of fish entering the fishway. Therefore, this utility model explores a fishway operation technology to reduce the water level difference between the inlet sections and the vertical slit flow velocity. Utility Model Content

[0007] The purpose of this invention is to provide a flow diversion system that adapts to the fluctuation of the inlet water level of a fishway. This flow diversion system can achieve precise control of the flow velocity in the pool chamber, is simple in system, easy in structure, low in operating cost, and highly automated. It is of great significance for maintaining stable flow velocity in the fishway pool chamber and promoting fish migration.

[0008] This utility model provides the following technical solution to achieve the above objectives:

[0009] A flow diversion system adapted to the variation of water level at the fishway inlet includes a fishway, a water level and flow velocity monitoring device, a diversion port device, branch diversion pipes and valves, and a main diversion pipe and main valve;

[0010] The diversion port device is located at the bottom of the pool or rest room in the downstream area of ​​the fishway and is connected to the branch diversion pipes; the flow rate is controlled by a valve at the end of each branch diversion pipe, and all branch diversion pipes converge into the main diversion pipe extending along the side wall of the fishway, with a main valve at the end of the main diversion pipe;

[0011] The pool chamber is equipped with a water level and flow velocity monitoring device to control the opening and closing range of the valves to regulate the diversion flow rate.

[0012] The fishway includes a fishway outlet, a fishway inlet, a pool chamber, and a resting room; the pool chamber is formed by staggered wide and narrow partitions, with vertical slits between the wide and narrow partitions serving as an upstream flow channel for fish.

[0013] Furthermore, the diversion device is specifically arranged at the bottom of a portion of the pool or rest area near the downstream fishway inlet.

[0014] Furthermore, the water level and flow velocity monitoring device includes a water level sensor arranged below the lowest water level in the pool chamber and a flow velocity sensor arranged in the vertical slit, which work together to achieve real-time monitoring of the water level in the pool chamber and the flow velocity in the vertical slit.

[0015] Furthermore, the diversion port device is located in the still water area downstream of the wide partition, and includes a funnel-shaped diversion port, an energy dissipation cover plate, and a fish barrier net. The diversion port connects the bottom of the pool chamber to the branch diversion pipe, and an energy dissipation cover plate is installed above it to avoid disturbing the flow in the pool chamber. Fish barriers nets are arranged around it to prevent fish from accidentally entering.

[0016] Furthermore, after the diversion port is vertically connected to the branch diversion pipe, the branch diversion pipe turns to extend in a direction parallel to the bottom slope of the fish passage, and the flow rate is controlled by a valve at the end; the drain outlet of the main diversion pipe is parallel to the outflow direction of the fish passage inlet and close to the fish passage inlet, and the water discharged from the diversion system is used to attract fish.

[0017] Furthermore, the water level and flow velocity monitoring device is connected to the valve signal of the branch pipe through a controller. Based on the water level and flow velocity data monitored by the water level sensor and flow velocity sensor, the opening and closing range of the valve is adjusted in real time to realize automatic control of the diversion flow.

[0018] Compared with existing technologies, this invention has the following advantages: This invention features a diversion system composed of pipe structures, which can adjust the flow rate and vertical slit velocity of each chamber in real time according to the upstream water flow requirements of fish. Simultaneously, the water discharged along the way can be used as inlet fish-attracting water, creating more suitable upstream water flow conditions for fish. This invention can adapt to operating conditions with large water level fluctuations at the fishway inlet. The diversion system is intelligent and automated, integrating operation, adjustment, monitoring, and feedback, greatly improving the efficiency of fishway water flow control. It is of great significance for maintaining stable flow velocity within the fishway chambers and promoting fish migration. Attached Figure Description

[0019] Figure 1 This utility model provides a schematic diagram of the overall layout of a flow diversion system that adapts to the variation of the inlet water level of a fishway.

[0020] Figure 2 A schematic diagram of the indoor water level and flow velocity monitoring device for fish passage pools and the structure of the diversion port and branch pipes provided by this utility model.

[0021] Figure 3 for Figure 2 A cross-sectional schematic diagram of the central diversion outlet and energy dissipation cover.

[0022] Figure 4 This is a schematic diagram of the diversion system layout according to an embodiment of the present utility model.

[0023] Attached reference numerals: 1-Fishway outlet, 2-Fishway inlet, 3-Pool chamber, 31-Wide partition, 32-Narrow partition, 33-Vertical slit, 34-Water level sensor, 35-Flow velocity sensor, 4-Main branch pipe, 5-Branch branch pipe, 6-Branch outlet device, 61-Branch outlet, 62-Energy dissipation cover, 63-Fish barrier net, 7-Valve, 8-Main valve, 9-Main branch pipe drain outlet, 10-Rest room. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and operating methods:

[0026] Please see Figure 1-3 The present invention provides a flow diversion system that adapts to the variation of water level at the fishway inlet, including a fishway, a water level and flow velocity monitoring device, a diversion port device 6, branch diversion pipes 5 and valves 7, a main diversion pipe 4 and a main valve 8.

[0027] The diversion device 6 is located at the bottom of a section of the pool chamber 3 or rest room 10 near the downstream fishway inlet and is connected to the branch diversion pipe 5. The flow rate is controlled by a valve 7 at the end of each branch diversion pipe 5. Each branch diversion pipe 5 merges into the main diversion pipe 4, which is set along the length of the side wall and passes through each pool chamber 3. A main valve 8 is arranged at the end of the main diversion pipe 4. A water level and flow rate monitoring device is arranged in each pool chamber 3 to control the opening and closing range of the valve 7.

[0028] The fishway includes a fishway outlet 1, a fishway inlet 2, a pool chamber 3, and a rest room 10. The pool chamber 3 is formed by several sets of partitions arranged in an alternating manner. The partitions include wide partitions 31 and narrow partitions 32. There is a vertical slit 33 between the wide partitions 31 and the narrow partitions 32, which serves as the main flow channel for fish to swim upstream.

[0029] The water level and flow velocity monitoring device includes a water level sensor 34 arranged at an elevation below the lowest water level in the pool chamber, and a flow velocity sensor 35 arranged in the vertical slit 33, to realize real-time monitoring of water level and flow velocity.

[0030] The diversion device 6 is located in the still water area near the downstream side of the wide partition 31. It includes a diversion port 61, an energy dissipation cover 62, and a fish barrier 63. The diversion port 61 is funnel-shaped. The branch diversion pipe 5 is connected to the bottom of the pool chamber through the diversion port 61. An energy dissipation cover 62 is arranged above the diversion port 61. The energy dissipation cover 62 can effectively prevent the water flow from the pool chamber 3 to the diversion port 61 from having an adverse effect on the flow state of the pool chamber. In addition, a fish barrier 63 is set around the energy dissipation cover 62 to prevent fish and other organisms from accidentally entering the diversion port.

[0031] The branch outlet 61 is vertically connected to the branch pipe 5, and then the branch outlet 5 turns to be parallel to the bottom slope of the fish passage. The flow rate at the end of the branch outlet 5 is controlled by the valve 7. The water in the pool chamber 3 flows from the branch outlet 61 into the branch pipe 5, and then into the main branch pipe 4. The drain outlet 9 of the main branch pipe is parallel to the outflow direction of the fish passage inlet 2 and is located near the fish passage inlet 2. The drainage of the branch system can be used to attract fish.

[0032] The water level and flow rate monitoring device is connected to the valve 7 of the branch pipe 5 through a controller, which controls the opening and closing range of the valve 7 and the diversion flow rate of the branch pipe 5, thus ensuring the automatic diversion of the fishway diversion system.

[0033] This utility model embodiment also provides an operation method for the flow diversion system along the fishway that adapts to the variation of the inlet water level, including the following steps:

[0034] S1. Critical Point Determination: Based on the maximum water level difference combination during fishway operation, determine the critical point at which the water depth along the fishway begins to change from upstream to downstream. The maximum water level difference combination during fishway operation includes the maximum water depth h at the fishway outlet. 进 and minimum water depth h 出 The combination of the fishway and the critical point where the water depth along the fishway begins to change from upstream to downstream is the critical point where the water depth along the fishway decreases. A flow diversion system along the fishway is arranged between this critical point and the downstream inlet of the fishway.

[0035] S2, Pre-calculation of diversion flow: Based on h 进 / h 出 Estimate the maximum diversion flow rate Q along the route. 弃 =(1-h 进 / h 出 )×Q 鱼 Q 鱼 The water depth at the fish passage inlet is h. 进 The corresponding discharge flow rate, the water level difference dH is taken as the difference between the downstream water level elevation and the lower edge elevation of the branch pipe diameter, based on dH and Q. 弃 Calculate the total water passage area of ​​each branch pipe 5; select an appropriate number of branch pipes 5 along the route, and estimate the water passage area of ​​each branch pipe 5; predict the diversion flow rate of each branch pipe 5 based on the fishway operating water level under different scenarios, and combine the water level-diversion flow rate relationship curves. When the water level changes upstream and downstream of the fishway, call the predicted diversion flow rate of the branch pipe 5 under similar scenarios to achieve rapid pre-adjustment of the diversion system.

[0036] S3. Initial valve opening: Under different water level combinations, the location of the pool where the water depth in the fish passage begins to change is determined based on the actual water level measured by the water level and flow velocity monitoring device. The valve 7 of the branch pipe 5 between the pool 3 and the fish passage inlet is then opened.

[0037] S4. Precise Adjustment: Based on the real-time monitoring of the pool water depth and vertical slit flow velocity by the water level and flow velocity monitoring device, the diversion flow rate of each branch pipe 5 is controlled in real time to achieve precise adjustment of the diversion system until the flow velocity of all vertical slits 33 in the fish passage is suitable for fish to swim upstream.

[0038] The following is a specific example to illustrate this:

[0039] Vertical slot fishway (such as) Figure 4 The outlet chamber (1#) has a water depth of 3.63m, and the inlet chamber (60#) has a water depth of 1.00m, with 60 chambers in between. A physical model test was conducted to measure the fishway discharge flow rate, the water depth along the flow path, and the maximum flow velocity at the vertical slits under these conditions. The test results show that the fishway discharge flow rate is 1.01m³ / h. 3 As shown in Table 1, the water depth changes in the pool are mainly concentrated near the fish passage inlet, and the closer to the inlet, the faster the water depth drops, and the faster the vertical slit flow velocity increases, with a maximum flow velocity of about 2.95 m / s, which far exceeds the swimming ability of fish, making it impossible for fish to swim upstream.

[0040] Table 1. Water depth and vertical slit flow velocity distribution along the experimental fishway.

[0041]

[0042] To accommodate the large water level fluctuations at the fishway inlet (outlet depth 3.63m, inlet depth 1.00m, fishway discharge rate Q), 鱼 =1.01m 3 A diversion system was installed along the route.

[0043] Based on the water level combination of the fishway operation, the critical point at which the water depth along the fishway begins to change from upstream to downstream is determined to be near the No. 1 rest room. A flow diversion system is arranged along the fishway between this critical point and the downstream inlet of the fishway.

[0044] Based on the fishway inlet water depth / outlet water depth h 进 / h 出= 1 / 3.63, estimate the flow rate Q along the route. 弃 =(1-h 进 / h 出 )×Q 鱼 =0.73m 3 / s, the water level difference dH is taken as the difference between the downstream water level elevation and the elevation of the lower edge of the diversion pipe diameter, based on dH and Q. 弃 Calculate the total cross-sectional area of ​​each branch pipe; arrange 13 branch pipes along the fishway, with each branch pipe having a cross-sectional area (approximately 0.7m in diameter). The flow rates of each branch pipe are shown in Table 3, and the water depth and vertical slit velocity along the fishway are shown in Table 4. After arranging the branch system, the water depth along the fishway becomes more uniform, and the vertical slit velocity decreases significantly.

[0045] Table 2. Arrangement of Branch Pipes in the Experimental Fishway

[0046]

[0047] Table 3. Percentage of flow rate of each diverter to the total flow rate of the fishway

[0048]

[0049] Table 4. Water depth and vertical flow velocity distribution along the experimental fishway.

[0050]

[0051] To more precisely adjust the flow rate of the branch pipes in the pool, the number of branch pipes can be increased. At the same time, based on the real-time monitoring of the pool water depth and vertical slit flow velocity by the monitoring system, the flow rate of each branch pipe can be controlled in real time until the flow velocity of all vertical slits in the fishway is suitable for fish to swim upstream.

[0052] Obviously, the above description is only a part of the embodiments of this utility model, and not all of the embodiments. The above description is only a specific implementation case of the utility model, and the technical features of this utility model are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of this utility model are covered by the protection scope of this utility model.

Claims

1. A flow diversion system adaptable to variations in fishway inlet water level, characterized in that: Includes fish passage, water level and flow velocity monitoring device, diversion port device (6), branch diversion pipe (5) and valve (7), main diversion pipe (4) and main valve (8); The diversion port device (6) is arranged at the bottom of the pool room (3) or rest room (10) in the downstream area of ​​the fishway and is connected to the branch diversion pipe (5); the flow rate at the end of each branch diversion pipe (5) is controlled by a valve (7), and each branch diversion pipe (5) merges into the main diversion pipe (4) extending along the side wall of the fishway, and the end of the main diversion pipe (4) is provided with a main valve (8). A water level and flow rate monitoring device is arranged in the pool chamber (3) to control the opening and closing range of the valve (7) to adjust the diversion flow rate; The fishway includes a fishway outlet (1), a fishway inlet (2), a pool chamber (3), and a rest room (10); the pool chamber (3) is formed by staggered wide partitions (31) and narrow partitions (32), and a vertical slit (33) is formed between the wide partitions (31) and the narrow partitions (32) as a channel for fish to move upstream.

2. The flow diversion system for adapting to the variation of water level at the fishway inlet according to claim 1, characterized in that: The diversion port device (6) is specifically arranged at the bottom of a portion of the pool chamber (3) or rest room (10) near the downstream fishway inlet.

3. The flow diversion system along the fishway inlet adapting to the variation of water level according to claim 1, characterized in that: The water level and flow velocity monitoring device includes a water level sensor (34) arranged below the lowest water level in the pool chamber (3) and a flow velocity sensor (35) arranged in the vertical slit (33). The two work together to achieve real-time monitoring of the water level in the pool chamber and the flow velocity in the vertical slit.

4. The flow diversion system along the fishway inlet adapting to the variation of water level according to claim 1, characterized in that: The diversion device (6) is located in the still water area downstream of the wide partition (31), including a funnel-shaped diversion port (61), an energy dissipation cover plate (62), and a fish barrier net (63). The diversion port (61) connects the bottom of the pool chamber (3) to the branch diversion pipe (5), and an energy dissipation cover plate (62) is installed above it to avoid disturbing the flow state of the pool chamber. A fish barrier net (63) is arranged around it to prevent fish from accidentally entering.

5. The flow diversion system along the fishway inlet adapting to the variation of water level according to claim 4, characterized in that: After the diversion port (61) is vertically connected to the branch diversion pipe (5), the branch diversion pipe (5) turns to extend in a direction parallel to the bottom slope of the fish passage, and the flow rate is controlled by the valve (7) at the end; the drain outlet (9) of the main diversion pipe (4) is parallel to the outflow direction of the fish passage inlet (2) and close to the fish passage inlet (2), and the water discharged by the diversion system is used to attract fish.

6. The flow diversion system along the fishway inlet adapting to the variation of water level according to claim 1, characterized in that: The water level and flow rate monitoring device is connected to the valve (7) of the branch pipe (5) via a controller. Based on the water level and flow rate data monitored by the water level sensor (34) and the flow rate sensor (35), the opening and closing range of the valve (7) is adjusted in real time to achieve automatic control of the diversion flow rate.

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