CN115726311A - Experimental device and experimental method for determining appropriate flow velocity of seedlings growing in river - Google Patents

Abstract

The invention discloses an experimental device and an experimental method for determining the suitable flow rate of Nanmiao in irrigation. The downstream end of the water tank is provided with a downstream water tank, the upstream end of the water tank is provided with a main branch and a branch branch, and the upstream end of the main branch is provided with a The first upstream water tank, the upstream end of the branch is provided with the second upstream water tank, the downstream water tank is connected with the first upstream water tank through the first connecting pipe, the downstream water tank is connected with the second upstream water tank through the second connecting pipe, and the fry release device is arranged on On the main branch, the fry trajectory capturing device is arranged at the confluence of the main branch and the branch branch, and the flow velocity measuring device and the water level regulating device are all arranged in the water tank. The present invention gradually adjusts the flow rate of the water tank and measures the flow velocity distribution at the corresponding position, counts the frequency at which the fry enters the downstream or branch, analyzes and obtains the appropriate flow velocity range required for the fry to enter the branch; and changes the confluence angle, flow rate, water depth and confluence ratio , which is suitable for the shape of the gate at the confluence of different rivers and lakes, and provides a certain technical reference for Guanjiang Nanmiao.

Description

A kind of experimental device and experimental method for determining the suitable flow rate of nano seedlings in Guanjiang

technical field

The invention belongs to the technical field of eco-hydraulics, and in particular relates to an experimental device and an experimental method for determining the suitable flow rate for irrigation of nano seedlings.

Background technique

In recent years, a large number of projects have been built in the Yangtze River Basin and the lakes connected to the river, which have destroyed the original hydrodynamic system of the river and lake system, and its ecological environment has also been increasingly damaged, seriously threatening the habitat of fish, water birds and other organisms land. With the country's emphasis on ecology and the deepening of society's research on the ecological environment, people began to shift more attention to the restoration of broken river and lake complex ecosystems. Guanjiang Nanmiao is one of the important technical measures. Guanjiang Namiao means that during the flood season of fish fry, that is, the period when a large number of fish fry appear and concentrate, the gates are properly opened to change the water flow environment, so that fry or juvenile fish can enter the lake to grow and fatten along the current or against the current. It is mainly used for blocking by gates and dams. It is a lake with natural water exchange between rivers and lakes. The main methods include forward irrigation and reverse irrigation. Downward irrigation means that the river water enters the lake, and juvenile fish also enter the lake with the river water; backward irrigation means that the lake water flows into the river, and fish fry are lured into the lake by using their habit of swimming against the current.

The current research results show that: the water flow structure is an important factor affecting the fish movement process, and the flow velocity is a typical factor to distinguish the water flow structure. The metabolites and metabolic rates of fish show different trends under different flow velocities, which also changes the fish. The swimming state, swimming speed, tail wagging frequency, tail wagging amplitude and other behaviors of the class. In addition, the confluence has strong turbulence and various eddy scales, and the Reynolds stress, turbulent kinetic energy, eddy direction and size of the water flow will also affect the movement of fish. Therefore, in order to optimize the joint dispatch of engineering groups, it is first necessary to determine the appropriate flow rate range during the irrigation of rivers and seedlings, so as to construct a suitable hydrodynamic system, which is conducive to the growth and reproduction of fish fry in the river and lake system. Therefore, it is of great practical significance to study the suitable range of flow velocity during irrigation of rivers and accepting seedlings, which can provide certain theoretical support for project scheduling.

Contents of the invention

Technical problem to be solved: In view of the above technical problem, the present invention provides an experimental device and an experimental method for determining the suitable flow velocity of seedlings in the irrigation river. According to the frequency of branches, the appropriate flow velocity range required for fish fry to enter the branches is obtained through analysis; and by changing the confluence angle, flow rate, water depth and confluence ratio, it is suitable for the gate shape of different rivers and lakes confluence, and provides certain technical references for the irrigation of seedlings .

Technical solution: In the first aspect, the present invention provides an experimental device for determining the suitable flow rate of seedlings in the irrigation river, including a water tank, a fry releasing device, a fry track capturing device, a flow velocity measuring device and a water level regulating device, and the downstream end of the water tank is provided with There is a downstream water tank, the upstream end of the tank is provided with a main branch and a branch branch, the upstream end of the main branch is provided with a first upstream water tank, the upstream end of the branch branch is provided with a second upstream water tank, and the downstream water tank The first connecting pipe is connected to the first upstream water tank, the downstream water tank is connected to the second upstream water tank through the second connecting pipe, the fry releasing device is arranged on the main branch, and the fry track capturing device is arranged on the main branch and the main branch At the confluence of the branches, the flow velocity measuring device and the water level regulating device are all arranged in the water tank.

Preferably, the fish fry release device includes a release channel, the bottom of the release channel is provided with a fish storage net, and the fish storage net is provided with a fish outlet, and a baffle is provided on the fish outlet, and the two sides of the baffle are The slideway is connected with the release channel, the upper part of the baffle is provided with a limit rod, the limit rod is provided with a limit hole, the release channel is provided with an elastic limit block, and the elastic limit block and the limit bit hole snap connection.

Preferably, the fry track capture device includes a fixed frame and a camera, the camera is arranged on the top of the fixed frame, and a non-slip rubber pad is provided at the contact between the fixed frame and the ground.

Preferably, the flow rate measurement device includes a bottom plate, a vertical plate, a mounting frame and a flow rate measuring instrument, the vertical plate is provided with a scale line, the vertical plate is vertically arranged at one end of the bottom plate, and the mounting frame is set On the vertical plate, and the mounting plate can move up and down along the vertical plate, the flow velocity measuring instrument is arranged on the mounting frame, and a stabilizing bar is arranged between the vertical plate and the bottom plate.

Preferably, the water level adjusting device includes a gate, a lifting bearing and an adjusting dial, one end of the lifting bearing is connected to the gate, and the other end is connected to the adjusting dial.

Preferably, the first connecting pipe is provided with a first valve, a first variable frequency water pump and a first flow meter.

Preferably, the second connecting pipe is provided with a second valve, a second frequency conversion water pump and a second flow meter.

Preferably, a first horizontal water grill is provided at the outlet of the first upstream water tank, and a second horizontal water grill is provided at the outlet of the second upstream water tank.

In the second aspect, the present invention provides a kind of experimental method that adopts the experimental device described in the first aspect to determine the suitable flow rate of irrigation river nano seedlings, comprising the following steps:

S1. Make the first upstream water tank and the second upstream water tank continuously filled with water, the water flow flows into the water tank, and flows out through the downstream water tank. After the water flow is stable, put the fry into the fry release device;

S2. Move the flow rate measuring device to the required measuring position;

S3, open the fish fry release device to make the fish fry swim downstream;

S4, turn on the camera in the fry track capture device, record the trajectory of the fry, and swim to the downstream of the main branch or the branch;

S5, start to measure the flow velocity, and measure the flow velocity of each area in the water tank through the flow velocity measuring device;

S6. Take the fry out of the water tank, gradually increase the flow rate of the branches from small to large, each time by 1L/s, repeat steps S1-S5, and obtain the experimental data of the set number of groups;

S7. Analyze the experimental data of the set number of groups obtained in step S6, make a frequency-velocity diagram of the fry entering the branch, and determine the corresponding suitable flow velocity range with the frequency of the fry entering the branch greater than 60% as the threshold.

Preferably, the relationship between the flow velocity V and the influencing factors is:

Among them, V is the flow velocity; a, a ₁ , b, b ₁ , c, c ₁ , d, d ₁ , e, e ₁ , and C are constants, which can be obtained by fitting experimental data; L is the body length of fry, and M is the fry weight, S is the turbulence intensity of the water flow, W is the vortex size, and q is the confluence ratio, that is, the ratio of branch flow to the total downstream flow after confluence.

Beneficial effects: 1) The present invention provides an experimental device and an experimental method for determining the suitable flow velocity of seedlings in the Guanjiang River, counts the results of fry entering the downstream and branch branches, and measures the flow velocity distribution at the confluence to obtain the appropriate flow rate for fry entering the branch branches. Velocity range; and can change the confluence angle, flow rate, water depth and confluence ratio, suitable for the gate shape of various rivers and lakes confluence;

2) The experimental device in the present invention can change various parameters such as flow velocity, water depth, confluence angle, number of fish fry, etc., and realizes the simulation experiment of the suitable flow velocity of fish during the on-site filling of the river and accepting seedlings. The experiment is convenient, the cost is low, and the results are intuitive;

3) In the present invention, the high-precision flow velocity measurement technology and statistical method are used to effectively simulate the appropriate flow velocity range required for the fry to enter the branches, and provide certain technical references for the implementation of the seedling irrigation in the river;

4) The fish fry release device in the present invention realizes the setting of different positions, number and size of fish fry, and the fry can adapt to the water flow environment in the fish storage net, the simulation results are accurate, and various experimental working conditions can be freely combined.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the experimental device of the present invention;

Fig. 2 is a structural representation of the fry releasing device;

Fig. 3 is the structural representation of fish fry track capture device;

Fig. 4 is a schematic structural view of a flow rate measuring device;

Fig. 5 is a structural schematic diagram of a water level regulating device;

Serial numbers in the figure: 1. Main branch; 2. Branch branch; 3. First upstream water tank; 4. Second upstream water tank; 5. Downstream water tank; 6. First connecting pipe; 7. Second connecting pipe; 8. Second connecting pipe 1. Frequency conversion water pump; 9. Second frequency conversion water pump; 10. First valve; 11. Second valve; 12. First flowmeter; 13. Second flowmeter; 14. First horizontal water grid; 15. Second 16. Fish fry release device; 17. Fish fry trajectory capture device; 18. Flow velocity measurement device; 19. Water level adjustment device; 20. Release channel; 21. Fish storage net; 22. Fish outlet; 23. Baffle plate; 24, slideway; 25, limit hole; 26, fixed frame; 27, non-slip rubber pad; 28, camera; 29, bottom plate; 30, stabilizer bar; ; 34, gate; 35, lifting bearing; 36, adjusting turntable; 37, water tank; 38, elastic limit block; 39, flow rate measuring instrument.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the present invention is described in detail:

Example 1

As shown in Figure 1-5, a kind of experimental device of determining the suitable flow velocity of Guanjiang Namiao comprises water tank 37, fish fry release device 16, fish fry trajectory capture device 17, flow velocity measuring device 18 and water level regulating device 19, and described water tank 37 The downstream end of the water tank 37 is provided with a downstream water tank 5, the upstream end of the water tank 37 is provided with a main branch 1 and a branch branch 2, the upstream end of the main branch 1 is provided with a first upstream water tank 3, and the upstream end of the branch branch 2 A second upstream water tank 4 is provided; the downstream water tank 5 is connected with the first upstream water tank 3 through the first connecting pipe 7, the downstream water tank 5 is connected with the second upstream water tank 4 through the second connecting pipe 7, and the The upstream water tank and the downstream water tank 5 are connected, so that the water flow can circulate in the water tank 37 to ensure the stability of the water flow in the water tank 37; the fry releasing device 16 is arranged on the main branch 1, and the fry trajectory capturing device 17 is arranged on the main branch 1 and branch 2, the flow velocity measuring device 18 and the water level regulating device 19 are both arranged in the water tank 37, and the fry releasing device 16 and the flow velocity measuring device 18 can move horizontally along the water tank 37.

Above-mentioned fry release device 16 comprises release channel 20, and the bottom of described release channel 20 is provided with and keeps fish net 21, and keeps fish net 21 and can adopt nylon net to make, and described fish net 21 is provided with fish outlet 22, and described fish outlet 22 A baffle 23 is arranged on the top, the two sides of the baffle 23 are connected with the release channel 20 through the slideway 24, the baffle 23 can slide along the slideway 24, the upper part of the baffle 23 is provided with a limit rod, the limit A limit hole 25 is provided on the position rod, and an elastic limit block 38 is provided on the release channel 20 , and the elastic limit block 38 is snap-connected with the limit hole 25 .

The above-mentioned fry track capture device 17 includes a fixed frame 26 and a camera 28, the camera 28 is arranged on the top of the fixed frame 26, and the fixed frame 26 is provided with a non-slip rubber pad 27 at the contact point with the ground.

Above-mentioned flow velocity measuring device 18 comprises base plate 29, vertical plate 31, mounting frame 32 and flow velocity measuring instrument 39, described vertical plate 31 is provided with scale line 33, can determine the measuring point of flow velocity measuring instrument 39 by crossing scale line 33 Position; the vertical plate 31 is vertically arranged at one end of the base plate 29, the mounting frame 32 is arranged on the vertical plate 31, and the mounting plate 32 can move up and down along the vertical plate 31, specifically, it can be mounted on the vertical plate 31 is provided with several bolt holes along the vertical direction, bolts are installed at the end of the mounting frame 32, the mounting frame 32 can move up and down relative to the vertical plate 31 through the cooperation of the bolts and the bolt holes, and the ADV flow rate measuring instrument 39 is arranged on the mounting frame 32. On the frame 32, a stabilizer bar 30 is provided between the vertical plate 31 and the bottom plate 29.

Above-mentioned water level regulating device 19 comprises gate 34, lifting bearing 35 and adjusting dial 36, and one end of described lifting bearing 35 is connected with gate 34, and the other end is connected with adjusting dial 36, can drive lifting bearing 35 to move up and down by rotating adjusting dial 36 , and then adjust the height of the gate 34 to control the water level of the water tank 37.

The first connecting pipe 6 is provided with a first valve 10 , a first variable frequency water pump 8 and a first flow meter 12 .

The second connecting pipe 7 is provided with a second valve 11 , a second frequency conversion water pump 9 and a second flow meter 13 .

A first horizontal water grill 14 is provided at the outlet of the first upstream water tank 3 , and a second horizontal water grill 15 is provided at the outlet of the second upstream water tank 4 to further stabilize the water flow in the water tank 37 .

Example 2

An experimental method for determining the suitable flow rate for Guanjiang Nanmiao comprises the following steps:

S1. Open the water inlet pipe so that the first upstream water tank 3 and the second upstream water tank 4 are continuously filled with water, turn on the first frequency conversion water pump 8 and the second frequency conversion water pump 9, adjust the first valve 10 and the first valve 11 to the set flow rate, and pass Adjust the turntable 32 to adjust the water level to the required height, and the water flow circulates in the water tank 37. After the water flow is stable, slide the baffle plate 23 in the fry release device 16 to the bottom end, so that the baffle plate 23 completely covers the fish outlet 22 , put the fry into the release channel 20 and enter the fish storage net 21;

S2, move the flow velocity measuring device 18 to the desired measurement position, adjust the mounting frame 32, adjust the ADV flow velocity measuring instrument 39 to the set water depth through the scale line 33 on the vertical plate 31;

S3. After the fry adapt to the water flow environment, open the baffle 23 to make the fry swim downstream through the fish outlet 22;

S4, start to measure the flow velocity, and move the base plate 29 to measure the flow velocity of the water flow in each area in the water tank;

S5, turn on the camera 28 in the fish fry trajectory capturing device, record the movement trajectory of the fry, and swim to the downstream of the water tank 37 or the branch 2;

S6. Take out the fry from the water tank 37, gradually increase the flow rate of the branch 2 from small to large, and increase 1L/s each time, repeat steps S1-S5, and obtain the experimental data of the set number of groups;

S7. Analyze the experimental data of the set number of groups obtained in step S6, make a frequency-velocity diagram of the fry entering the branch 2, and determine the corresponding suitable flow velocity range with the frequency of the fry entering the branch 2 being greater than 60% as the threshold.

The present invention summarizes predecessors' response relationship between fish and water flow velocity and obtains: fry body length ( L ), weight ( M ), water flow turbulence intensity ( S ) and vortex size ( W ) are closely related to fish movement. At the confluence of river channels, the discharge ratio q of the two branches is one of the main factors affecting the flow structure. Based on this, the present invention intends to propose the relationship between fish suitable flow velocity and these influencing factors:

，x _i 是坐标系的三个 方向，u _i 是对应坐标方向的流速值；V为测量区域的平均流速，各点的流速值可通过ADV仪器 测量得到；q为汇流比，即q=支汊流量/汇合后下游总流量。Among them, a, a ₁ , b, b ₁ , c, c ₁ , d, d ₁ , e, e ₁ , C are constants, which are obtained by fitting the experimental results; the fry body length L and weight M are obtained by measurement; the water flow The turbulence intensity S is calculated according to the SVP assumption proposed by Professor Goodwin. S is the total hydraulic strain, that is, the absolute value of the gradient of the velocity in all directions in the three-dimensional coordinate system,

, x _i are the three directions of the coordinate system, u _i is the flow velocity value corresponding to the coordinate direction; V is the average flow velocity of the measurement area, and the flow velocity value of each point can be obtained by ADV instrument measurement; q is the confluence ratio, that is, q=branch Branch flow/total downstream flow after confluence.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (10)

1. An experimental device for determining the suitable flow rate of seedlings in Guanjiang, characterized in that it includes a water tank (37), a fry releasing device (16), a fry track capturing device (17), a flow rate measuring device (18) and a water level regulating device (19), the downstream end of the water tank (37) is provided with a downstream water tank (5), the upstream end of the water tank (37) is provided with a main branch (1) and a branch branch (2), and the main branch (1 ) is provided with a first upstream water tank (3), the upstream end of the branch (2) is provided with a second upstream water tank (4), and the downstream water tank (5) is connected to the The first upstream water tank (3) is connected, the downstream water tank (5) is connected with the second upstream water tank (4) through the second connecting pipe (7), and the fry releasing device (16) is arranged on the main branch (1) , the fry trajectory capture device (17) is set at the confluence of the main branch (1) and the branch branch (2), and the flow rate measuring device (18) and the water level regulating device (19) are both set in the water tank (37). 2. An experimental device for determining the suitable flow rate of nano seedlings in Guanjiang according to claim 1, characterized in that: the fry release device (16) includes a release channel (20), and the bottom of the release channel (20) A fish storage net (21) is provided, the fish storage net (21) is provided with a fish outlet (22), the fish outlet (22) is provided with a baffle (23), and the two sides of the baffle (23) The edge is connected with the release channel (20) through the slideway (24), the upper part of the baffle (23) is provided with a limit rod, and the limit rod is provided with a limit hole (25), and the release channel (20) An elastic limit block (38) is arranged on the top, and the elastic limit block (38) is snap-connected with the limit hole (25). 3. An experimental device for determining the suitable flow rate of Nanjiang seedlings according to claim 1, characterized in that: the fry trajectory capture device (17) includes a fixed frame (26) and a camera (28), and the camera (28) is arranged on the top of the fixed frame (26), and the fixed frame (26) is provided with a non-slip rubber pad (27) at the contact point with the ground. 4. An experimental device for determining the suitable flow velocity of Nanmiao seedlings in Guanjiang according to claim 1, characterized in that: the flow velocity measuring device (18) includes a bottom plate (29), a vertical plate (31), a mounting frame ( 32) and a flow rate measuring instrument (39), the vertical plate (31) is provided with a scale line (33), the vertical plate (31) is vertically arranged at one end of the bottom plate (29), and the mounting bracket ( 32) Set on the vertical plate (31), and the mounting plate (32) can move up and down along the vertical plate (31), the flow rate measuring instrument (39) is set on the mounting frame (32), the vertical A stabilizing bar (30) is provided between the plate (31) and the bottom plate (29). 5. An experimental device for determining the suitable flow rate of Nanmiao in Guanjiang according to claim 1, characterized in that: the water level regulating device (19) includes a gate (34), a lifting bearing (35) and an adjusting dial (36 ), one end of the lifting bearing (35) is connected to the gate (34), and the other end is connected to the adjusting dial (36). 6. An experimental device for determining the suitable flow rate of Nanmiao in Guanjiang according to claim 1, characterized in that: the first connecting pipe (6) is provided with a first valve (10), a first variable frequency water pump ( 8) and the first flow meter (12). 7. An experimental device for determining the suitable flow rate of Nanmiao in Guanjiang according to claim 1, characterized in that: the second connecting pipe (7) is provided with a second valve (11), a second frequency conversion water pump ( 9) and the second flow meter (13). 8. An experimental device for determining the suitable flow rate of Nanmiao in Guanjiang according to claim 1, characterized in that: the outlet of the first upstream water tank (3) is provided with a first horizontal water grille (14), A second horizontal water grille (15) is provided at the outlet of the second upstream water tank (4). 9. an experimental method adopting the experimental device described in any one of claims 1-8 to determine the suitable flow velocity of Guanjiang Nanmiao, is characterized in that, comprises the following steps: S1. Make the first upstream water tank (3) and the second upstream water tank (4) continuously filled with water, the water flows into the water tank (37) and flows out through the downstream water tank (5). After the water flow is stable, put the fry into the fry release device ( 16) in; S2. Move the flow rate measuring device (18) to the required measuring position; S3, open the fry release device (16), so that the fry swim downstream; S4, turn on the camera (28) in the fish fry trajectory capture device (17), record the movement trajectory of the fry, and swim to the downstream of the main branch (1) or the branch branch (2); S5. Start to measure the flow velocity, and measure the water flow velocity in each area in the water tank (37) through the flow velocity measuring device (18); S6. Take out the fry from the water tank (37), gradually increase the flow rate of the branch (2) from small to large, each time by 1L/s, repeat steps S1-S5, and obtain the experimental data of the set number of groups; S7. Analyze the experimental data of the set number of groups obtained in step S6, make a frequency-velocity diagram of the fry entering the branch (2), and determine the corresponding suitable flow rate with the frequency of the fry entering the branch (2) being greater than 60% as the threshold scope. 10. according to claim 9, a kind of experimental method of determining suitable flow velocity of irrigation river nano seedlings is characterized in that, the relational expression of described flow velocity V and influencing factor is:

Among them, V is the flow velocity; a, a ₁ , b, b ₁ , c, c ₁ , d, d ₁ , e, e ₁ , and C are constants, which are obtained by fitting experimental data; L is the body length of fry, and M is Fish fry weight, S is the turbulence intensity of water flow, W vortex size, q is the confluence ratio, that is, the ratio of branch flow to the total downstream flow after confluence.

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