Open channel flow adjusting device and adjusting method

Abstract

The invention discloses an open channel flow adjusting device and method, and the open channel flow adjusting device comprises an adjustable gate installed in an open channel and an adjustable overturning weir arranged at the position two meters behind the adjustable gate; a data real-time acquisition device is arranged in the open channel and used for acquiring the flow speed and the water level of water flow in the open channel. According to the method, on the basis of a sluice-weir series connection installation mode, by referring to a traditional flow calculation model, calculation of the lockage flow is achieved by obtaining information such as the sluice opening degree, the weir height, the water level in front of the sluice and the flow speed, the sluice opening time is predicted through the water amount required by the downstream, the flow can be adjusted by adjusting the sluice opening degree and the weir height, and dynamic adjustment of the lockage flow is achieved; the open channel flow calculation method is less in information acquisition, simple and convenient in calculation and low in technical requirements on operators, improves the working efficiency, reduces the waste of water resources and field human resources, reduces the field management cost, and lays a foundation for realizing high-standard farmlands.

Description

Technical Field

[0001] The present invention belongs to the technical field of agricultural automation machinery and equipment, and in particular relates to an open channel flow regulating device and a regulating method. Background Art

[0002] At present, open channel irrigation in farmland is still mainly based on flooding and manual experience. It is difficult to scientifically adjust the water volume according to the season. The flow regulation methods and technologies are not intelligent and automated, and the labor cost and time cost of flow regulation in open channels are high. Nowadays, most of the open channel flow regulation methods are completed by adjusting the gate opening, but the traditional open channel flow formula can no longer meet the accuracy requirements of field use. The flow regulation has low accuracy and poor dynamic regulation performance, resulting in a waste of water resources. In severe cases, it can cause the seedlings to be submerged.

[0003] In order to solve the above problems, CN201810175872.X discloses a single gate flow calibration method and device for an open channel water transfer channel, which collects the flow rate and its corresponding gate opening and water level difference before and after the gate through measuring equipment, and obtains the size of three parameters of the model based on the measured data, obtains the final CAP model, and substitutes the measured upstream and downstream water level difference and gate opening into the model to finally obtain the gate flow rate. However, the solution is relatively cumbersome and complicated for the calculation of flow, requires obtaining more parameters for calculation, and has high technical requirements for gate operators. Summary of the invention

[0004] In view of the above-mentioned problems, the present invention proposes an open channel flow regulating device and a regulating method. Based on the serial installation of gates and weirs and referring to the traditional flow calculation model, the flow rate passing through the gate is calculated by obtaining information such as gate opening, weir height, water level in front of the gate and flow velocity. The gate opening time is predicted by the required water volume downstream. The flow rate can be adjusted by adjusting the gate opening and the weir height, thereby realizing dynamic regulation of the flow rate passing through the gate. The open channel flow calculation method obtains less information and is simple to calculate. It does not require high technical skills from the operator, thereby improving operating efficiency, reducing the waste of water resources and field human resources, and reducing field management costs, laying the foundation for achieving high-standard farmland.

[0005] The above purpose is achieved through the following technical solutions:

[0006] The present invention first provides an open channel flow regulating device, comprising an adjustable gate installed in the open channel and an adjustable flip weir arranged two meters behind the adjustable gate; a real-time data acquisition device is arranged in the open channel for obtaining the flow velocity and water level of the water flow in the open channel.

[0007] Furthermore, the real-time data collection device includes a Doppler current meter and a radar water level meter. The Doppler current meter is installed on one side of the channel bottom to collect the flow velocity V0 before the gate, the radar water level meter is installed on both sides of the open channel to collect the water level H before the gate, the pull-wire sensor is installed above the gate to collect the gate opening e, and the angle sensor is installed below the adjustable flip weir to measure the weir height H t .

[0008] Furthermore, the adjustable gate includes a gate plate, a gate frame, a screw, a main control module, a worm gear hoist, a motor and a motor drive device; wherein the gate frame is installed in the open channel by cement pouring; the motor and the motor drive device drive the screw through the worm gear hoist to complete the power transmission; the gate plate and the screw are connected by a pin shaft; the gate plate moves in the gate frame under the transmission action of the screw and the worm gear hoist; the pull wire sensor is fixed to the gate frame by bolts; the main control module is fixed to the gate frame by bolts, and the flow rate is calculated using the water flow data collected by the real-time data acquisition device, and the motor and the motor drive are adjusted in combination with the gate opening information collected by the pull wire sensor to complete the adjustment of the gate opening, thereby adjusting the open channel flow rate.

[0009] Furthermore, the flip weir includes a universal joint base, a weir plate, a universal joint cross axis, a hydraulic cylinder, and a flip weir body, wherein the universal joint base is fixed in the open channel by bolts; one end of the hydraulic cylinder is fixed to the universal joint base by a universal joint cross axis, and the other end is fixed to the lifting ear of the weir plate; the angle sensor is installed on the flip axis of the flip weir body in a bolted manner, and the inclination angle information collected and fed back by the angle sensor in real time is combined with the weir height information issued by the main control module, and the hydraulic cylinder is used to adjust the inclination angle of the weir plate to achieve the purpose of adjusting the weir height.

[0010] Furthermore, the main control module includes a programmable controller, a power supply, and a flow calculation device.

[0011] The present invention also provides a method for regulating open channel flow using the above-mentioned open channel flow regulating device, the method comprising the following steps:

[0012] S1. Combining the gate and weir flow models, a preliminary model for open channel flow calculation based on sluice and weir series regulation is constructed as follows:

[0013]

[0014] Where: srepresents the flooding coefficient, u0 represents the flow coefficient, b represents the gate width, ξ represents the local head loss coefficient; g represents the gravitational acceleration; Hs represents the head above the weir; Q represents the open channel flow; V0 represents the flow velocity before the gate, which is collected by the Doppler flowmeter; H represents the water level before the gate, which is collected by the radar water level meter; e represents the gate opening, which is collected by the pull-wire sensor; H t Indicates the height of the weir, which is acquired by the angle sensor;

[0015] S2. Construction of the traffic calculation model, specifically including the following steps:

[0016] S2-1. According to the specific dimensions of the existing open channel, gates and weirs, an open channel model with gates and weirs in series was built in Solid Works. The open channel model was simplified according to the control principle of the gates and weirs. The built open channel model was saved in x_t format and imported into ANSYS Fluent fluid simulation software. With the help of ANSYS Fluent fluid simulation software, the built open channel model was meshed, locally meshed and features were removed to obtain an ideal three-dimensional geometric model;

[0017] S2-2. Based on the preliminary calculation model of open channel flow established in step S1, factors affecting open channel flow are obtained, and the value range of each influencing factor is selected according to the material and shape of the open channel. Combined with the ANSYS Fluent fluid simulation method, a single factor test with open channel flow as the evaluation index is completed to clarify the degree of influence on the flow;

[0018] S2-3. Using Design expert analysis software and Fluent to obtain simulated flow data, a four-factor three-level response surface experiment based on open channel flow was built to screen out the first-order terms, interaction terms and quadratic terms that have a significant impact on open channel flow. Combined with variance analysis, the model correlation coefficient R was obtained. 2 =0.9905, indicating that the constructed model has good reproducibility;

[0019] S2-4. Combined with response surface analysis, the water level H before the gate, the flow velocity V0 before the gate, the gate opening e and the weir height H are obtained based on the sluice-weir series regulation method. t quadratic multinomial regression model for the moderating variables;

[0020] S3. Analyze the influencing factors of the preliminary open channel flow calculation model based on the series regulation of gates and weirs built in step S1, fit the flow calculation model built in step S2 according to the measured data, obtain the open channel flow fitting model based on the series regulation of gates and weirs, bring the flow parameters in the measured data into the flow formula below, and obtain the gate flow Q S , the formula is as follows:

[0021]

[0022] Among them, H, V0, e, H t Measured by a real-time data acquisition device;

[0023] S4. When irrigation is carried out, the real-time data acquisition device obtains water flow information, the pull-wire sensor on the adjustable gate collects gate opening information, and the angle sensor on the flip weir collects weir height information and transmits it to the flow calculation device; the flow calculation device calculates the current open channel flow Q1 according to steps S1-S3;

[0024] S5. The irrigation time is obtained based on the amount of water required for farmland irrigation and the open channel flow Q1 obtained in step S4. If the irrigation time does not meet the irrigation demand, the opening of the gate and the reversing weir is adjusted to obtain the gate flow Q2 that meets the operation demand.

[0025] Furthermore, the specific method of adjusting the opening of the gate and the reversing weir in step S5 includes:

[0026] Adjust the gate opening: The main control module uses RS485 communication to control the motor and motor drive device of the adjustable gate. The motor and motor drive device drive the worm gear hoist, which in turn drives the screw rod to drive the gate plate to adjust the gate opening. Combined with the gate opening information fed back by the pull-wire sensor, the gate opening information is obtained in real time, and the gate opening is adjusted until the opening requirement is met;

[0027] Adjust the opening of the flip weir: The main control module sends the adjusted weir height information according to the irrigation time and irrigation water demand, and controls the hydraulic cylinder to adjust the feed amount of the cylinder to complete the adjustment of the flip weir height. Combined with the information feedback from the angle sensor, the weir height H is obtained in real time. t , control the hydraulic cylinder to adjust the weir height until the weir height requirement is met. According to the adjusted gate opening e and weir height H t Carry out secondary confirmation of irrigation flow and irrigation time to complete the main flow control process.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention is used to realize accurate calculation and dynamic regulation of flow rate during open channel irrigation, and comprises an open channel sluice weir connected in series with a water control device, a real-time data acquisition device, and a flow calculation device; the open channel flow rate is adjusted by connecting the open channel sluice weir in series with the water control device, and the water level, flow velocity, gate opening, weir height and other information in the open channel are collected by the real-time data acquisition device, and the open channel flow rate is accurately calculated in conjunction with the flow calculation device, and the irrigation time is calculated by the downstream water demand, thereby realizing accurate control of the irrigation water volume, reducing the waste of water resources and human resources, and improving agricultural production efficiency and intelligence level.

[0030] 2. The present invention can also adjust the open channel flow rate according to different time and water demand requirements, shorten the open channel irrigation time, and improve the timeliness of farmland irrigation. The flow rate can also be adjusted at any time according to different needs, thereby improving the dynamic adjustment ability of open channel irrigation and laying the foundation for solving problems such as inaccurate and non-standard farmland irrigation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is the layout diagram of the open channel installation;

[0032] Figure 2 It is a fluid simulation model diagram;

[0033] Figure 3 It is the fluid simulation volume cloud map;

[0034] Figure 4 It is the flow chart of open channel flow regulation;

[0035] Figure 5 It is a diagram of the series regulation device of the open channel sluice and weir;

[0036] Figure 6 It is a detailed drawing of the adjustable gate;

[0037] Figure 7 It is a detailed drawing of the flip weir;

[0038] Name of the label in the figure:

[0039] 1. Open channel, 101. Real-time data acquisition device, 1011. Doppler flowmeter, 1012. Radar water level gauge, 1013. Pull-wire sensor, 1014. Angle sensor, 2. Adjustable gate, 201. Gate plate, 202. Gate frame, 203. Screw, 204. Main control module, 2041. Flow calculation device, 205. Worm gear hoist, 206. Motor and motor drive device, 3. Flip weir, 301. Universal joint base, 302. Weir plate, 303. Universal joint cross shaft, 304. Hydraulic cylinder, 305. Flip weir body. DETAILED DESCRIPTION

[0040] The open channel flow regulating device and regulating method of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments.

[0041] like Figure 1As shown, in order to ensure the smooth flow of water in front of the weir behind the gate, reduce the loss of water along the way, and improve the accuracy of water flow information and measurement stability, a reversing weir is installed 2 meters behind the gate; the operating conditions of the open channel are relatively harsh, there are many debris on the water surface, and the mud at the bottom of the channel is seriously silted. The traditional flow sensor has certain requirements for water quality and installation position. The above reasons lead to large errors in traditional flow sensors. The present invention is based on the series adjustment method of the gate and weir, combining two open channel flow calculation models, without the need for special treatment of the open channel, and has strong dynamic adjustment ability for open channel flow and adaptability to complex open channel operating environments. The gate and reversing weir opening can be flexibly adjusted according to the irrigation water volume and irrigation time to meet irrigation needs.

[0042] Embodiment 1:

[0043] like Figure 5 As shown, the open channel flow regulating device of this embodiment includes an adjustable gate 2 installed in the open channel 1 and an adjustable flip weir 3 arranged two meters behind the adjustable gate 2; a real-time data acquisition device 101 is arranged in the open channel 1 for obtaining the flow velocity and water level of the water flow in the open channel.

[0044] In this embodiment, the real-time data acquisition device 101 includes a Doppler current meter 1011 and a radar water level meter 1012. The Doppler current meter 1011 is installed on one side of the channel bottom to collect the flow velocity V0 before the gate, and the radar water level meter 1012 is installed on both sides of the open channel to collect the water level H before the gate and the weir. The pull-wire sensor 1013 is installed above the gate 2 to collect the gate opening e, and the angle sensor 1014 is installed below the adjustable flip weir 3 to measure the weir height H. t .

[0045] like Figure 6 As shown, in this embodiment, the adjustable gate 2 includes a gate plate 201, a gate frame 202, a screw rod 203, a main control module 204, a worm gear hoist 205, and a motor and a motor drive device 206; wherein the gate frame 202 is installed in the open channel 1 by cement pouring; the motor and the motor drive device 206 drive the screw rod 203 through the worm gear hoist 205 to complete the power transmission; the gate plate 201 and the screw rod 203 are connected by a pin shaft; the gate plate 201 is connected to the screw rod 203 and the The worm gear hoist 205 moves in the gate frame 202 under the transmission action; the wire sensor 1013 is fixed to the gate frame 202 by bolts; the main control module 204 is fixed to the gate frame 202 by bolts, and the flow rate is calculated using the water flow data collected by the real-time data acquisition device 101, and the motor and motor drive 206 are adjusted in combination with the gate opening information collected by the wire sensor 1013 to complete the adjustment of the gate opening, thereby adjusting the open channel flow rate.

[0046] like Figure 7As shown, in this embodiment, the flip weir 3 includes a universal joint base 301, a weir plate 302, a universal joint cross shaft 303, a hydraulic cylinder 304, and a flip weir body 305, wherein the universal joint base 301 is fixed in the channel of the open channel 1 by bolts; one end of the hydraulic cylinder 304 is fixed to the universal joint base 301 by the universal joint cross shaft 303, and the other end is fixed to the lifting ear of the weir plate 302; the angle sensor 1014 is installed on the flip axis of the flip weir body 305 in a bolted manner, and the inclination angle information collected and fed back by the angle sensor in real time is combined with the weir height information issued by the main control module 204, and the hydraulic cylinder 304 is used to adjust the inclination angle of the weir plate to achieve the purpose of adjusting the weir height.

[0047] In this embodiment, the main control module 204 includes a programmable controller, a power supply, and a flow calculation device 2041 .

[0048] The main control module 204 is the control core of the gate and weir, including a programmable controller, a power supply and a flow calculation device 2041. Its working process is that when irrigation is carried out, the real-time data acquisition device 101 obtains water flow information, the pull-wire sensor 1013 on the adjustable gate 2 collects gate opening information, and the angle sensor 1014 on the flip weir 3 collects the height information of the weir and transmits it to the flow calculation device 2041 for flow prediction. The irrigation time is calculated according to the required water volume. If the irrigation time does not meet the irrigation demand, the opening of the gate and the flip weir is adjusted. The main control module 204 uses RS485 communication to control the adjustable gate. The motor and motor drive device 206 of the gate 2 drive the worm gear hoist 205, which in turn drives the screw rod 203 to drive the gate plate 201 to adjust the gate opening. Combined with the gate opening information fed back by the pull-wire sensor 1013, the gate opening information is obtained in real time, and the gate opening is adjusted until the opening requirement is met; further, the main control module 204 sends the required weir height information, controls the hydraulic cylinder 304 to adjust the feed amount of the cylinder to complete the weir height adjustment, combines the information feedback of the angle sensor 1014, obtains the weir height information in real time, and controls the hydraulic cylinder 304 to adjust the weir height until the weir height requirement is met. According to the adjusted gate opening and weir height, the irrigation flow and irrigation time are reconfirmed to complete the main flow control process.

[0049] Embodiment 2:

[0050] A method for regulating open channel flow using the open channel flow regulating device described in Example 1 comprises the following steps:

[0051] 1) Use measurement equipment such as radar water level gauges and Doppler flow meters to collect data on water flow and sluice openings;

[0052] 2) Combining the two flow models of gate and weir, a preliminary model for open channel flow calculation based on series regulation of gate and weir is constructed as follows:

[0053]

[0054] Where: s represents the flooding coefficient, u0 represents the flow coefficient, b represents the gate width, ξ represents the local head loss coefficient; g represents the gravitational acceleration; Hs represents the head on the weir; Q represents the open channel flow; V0 represents the flow velocity before the gate, which is collected by the Doppler flowmeter 1011; H represents the water level before the gate, which is collected by the radar water level meter 1012; e represents the gate opening, which is collected by the pull-wire sensor 1013; H t Indicates the weir height. In this embodiment, a thin-walled weir is used, and the weir height approximately represents the water level behind the gate, which is collected by the angle sensor 1014.

[0055] The influencing factors of the preliminary model were analyzed, and the flow calculation model was fitted according to the measured data to obtain the open channel flow fitting model based on the sluice and weir series regulation method. The flow parameters of the measured data were introduced into the flow formula to obtain the gate flow Q. S , the formula is as follows:

[0056]

[0057] Among them, H, V0, e, H t is the parameter that needs to be measured.

[0058] 3) Real-time data acquisition device, used to collect the actual information before the gate and the weir, namely the water level H before the gate, the flow velocity V0 before the gate, the gate opening e and the weir height H t Other related data

[0059] The flow calculation device is used to integrate and calculate the water flow information collected by each sensor, and substitute it into the open channel flow calculation formula based on the series regulation of the gate and weir to calculate the corresponding gate flow Q1.

[0060] 4) According to the amount of water required for farmland irrigation, the irrigation time is obtained in combination with the above flow rate;

[0061] 5) Reasonable gate opening and weir height information can be calculated based on irrigation time and irrigation water demand, and the required gate flow rate Q2 can be obtained by adjusting the gate / weir;

[0062] like Figure 2 As shown in the figure, the construction method of the flow calculation model is as follows:

[0063] According to the specific dimensions of the existing open channel, gates and weirs, an open channel model with gates and weirs in series was built in Solid Works, and the open channel model was simplified according to the control principle of the gates and weirs. The built open channel model was saved in x_t format and imported into ANSYS Fluent software. With the help of Fluent fluid simulation software, a series of repair work such as meshing, local mesh encryption, and feature removal was performed on the built open channel model to obtain an ideal three-dimensional geometric model, such as Figure 2 shown.

[0064] Combination Figure 3 As shown in the figure, the repair work of the open channel simulation model was completed. According to the preliminary calculation model of the open channel flow, the main factors affecting the open channel flow were obtained. The value range of each influencing factor was selected according to the material and shape of the open channel. Combined with the Fluent fluid simulation method, a single factor test with the open channel flow as the evaluation index was completed to clarify the degree of influence on the flow. Using the Design expert analysis software, combined with Fluent to obtain the simulated flow data, a four-factor three-level response surface test based on the open channel flow was built, and the linear terms, interaction terms and quadratic terms that have a significant impact on the open channel flow were screened out. Combined with variance analysis, the model correlation coefficient R 2 =0.9905, the model built has good reproducibility; combined with response surface analysis, the water level H before the gate, the flow velocity V0 before the gate, the gate opening e and the weir height H based on the sluice-weir series regulation method are obtained. t The quadratic multinomial regression model for regulating variables was verified by field experiments and was found to be reliable in regulating open channel flow.

[0065] like Figure 4 As shown, an open channel flow control device and method for series regulation of gates and weirs are described as a whole in combination with a complete embodiment:

[0066] S101, release water upstream for irrigation operations;

[0067] S102, the wire sensor and the angle sensor measure the weir height and the gate opening, and transmit the measurement data to the controller of the flow calculation device;

[0068] S103, when the water flow reaches the measuring position, the radar water level meter and the Doppler current meter obtain the water level and flow rate information and transmit it to the controller;

[0069] S104, the controller sends the collected information to the flow calculation device;

[0070] S105, the flow calculation device calculates the current flow rate through the gate according to the existing information;

[0071] S106, calculating the irrigation time according to the required water volume;

[0072] S107. Determine whether the irrigation requirements are met based on the calculated irrigation flow and irrigation time; if not, obtain reasonable gate opening and weir height information based on the required irrigation time, and complete open channel flow regulation by adjusting the gate opening and weir height until the irrigation time and irrigation water volume reach an acceptable range; if yes, complete open channel flow regulation, and reset the gate and weir.

[0073] The method of the present invention was used to perform model simulation and experimental verification, and the results are shown in Table 1 and Table 2 respectively:

[0074] Table 1 Model simulation results

[0075]

[0076]

[0077] Table 2 Test verification results

[0078]

[0079] It can be seen from the simulation results in Table 1 and the experimental verification results in Table 2 that the average error of the flow calculation model of the present invention for predicting open channel flow is 11.4%, which has a good prediction effect on open channel flow, improves the accuracy of flow control by gates and weirs, and lays a theoretical foundation for solving the problems of inaccurate control and unstable adjustment of open channel flow during open channel irrigation.

Claims

1. An open channel flow regulating device, characterized in that: The invention comprises an adjustable gate (2) installed in an open channel (1) and an adjustable flip weir (3) arranged two meters behind the adjustable gate (2); a real-time data acquisition device (101) is arranged inside the open channel (1) for acquiring the flow velocity and water level of the water flow in the open channel.

2. An open channel flow regulating device according to claim 1, characterized in that: The real-time data acquisition device (101) comprises a Doppler current meter (1011) and a radar water level meter (1012), wherein the Doppler current meter (1011) is installed at one side of the channel bottom to collect the flow velocity V0 before the gate, the radar water level meter (1012) is installed at both sides of the open channel to collect the water level H before the gate, the pull-wire sensor (1013) is installed above the gate (2) to collect the gate opening e, and the angle sensor (1014) is installed below the adjustable flip weir (3) to measure the weir height H t .

3. An open channel flow regulating device according to claim 1, characterized in that: The adjustable gate (2) comprises a gate plate (201), a gate frame (202), a screw (203), a main control module (204), a worm gear hoist (205), a motor and a motor drive device (206); wherein the gate frame (202) is installed in an open channel (1) by cement pouring; the motor and the motor drive device (206) drive the screw (203) through the worm gear hoist (205) to complete the power transmission; the gate plate (201) and the screw (203) are connected by a pin shaft; the gate plate (201) is fixed on the screw (203); 3) moves in the gate frame (202) under the driving action of the worm gear hoist (205); the wire sensor (1013) is fixed to the gate frame (202) by bolts; the main control module (204) is fixed to the gate frame (202) by bolts, and uses the water flow data collected by the real-time data acquisition device (101) to calculate the flow rate, and adjusts the motor and the motor drive (206) in combination with the gate opening information collected by the wire sensor (1013), completes the adjustment of the gate opening, and then adjusts the open channel flow rate.

4. An open channel flow regulating device according to claim 3, characterized in that: The overturning weir (3) comprises a universal joint base (301), a weir plate (302), a universal joint cross shaft (303), a hydraulic cylinder (304), and an overturning weir body (305), wherein the universal joint base (301) is fixed in the channel of the open channel (1) by means of bolts; one end of the hydraulic cylinder (304) is fixed to the universal joint base (301) by means of the universal joint cross shaft (303), and the other end is fixed to the lifting lug of the weir plate (302); an angle sensor (1014) is installed on the overturning shaft of the overturning weir body (305) by means of bolt connection, and according to the inclination information collected and fed back by the angle sensor in real time, combined with the weir height information sent by the main control module (204), the inclination angle of the weir plate is adjusted by means of the hydraulic cylinder (304), so as to achieve the purpose of adjusting the weir height.

5. An open channel flow regulating device according to claim 4, characterized in that: The main control module (204) comprises a programmable controller, a power supply, and a flow calculation device (2041).

6. A method for regulating open channel flow using the open channel flow regulating device according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: S1. Combining the gate and weir flow models, a preliminary model for open channel flow calculation based on sluice and weir series regulation is constructed as follows: Where: s represents the flooding coefficient, u0 represents the flow coefficient, b represents the gate width, ξ represents the local head loss coefficient; g represents the gravitational acceleration; Hs represents the water head above the weir; Q represents the open channel flow; V0 represents the flow velocity before the gate, which is collected by the Doppler flow meter (1011); H represents the water level before the gate, which is collected by the radar water level meter (1012); e represents the gate opening, which is collected by the pull-wire sensor (1013); H t represents the height of the weir, which is acquired by the angle sensor (1014); S2. Construction of the traffic calculation model, specifically including the following steps: S2-1. According to the specific dimensions of the existing open channel, gates and weirs, an open channel model with gates and weirs in series was built in Solid Works. The open channel model was simplified according to the control principle of the gates and weirs. The built open channel model was saved in x_t format and imported into ANSYS Fluent fluid simulation software. With the help of ANSYS Fluent fluid simulation software, the built open channel model was meshed, locally meshed and features were removed to obtain an ideal three-dimensional geometric model; S2-2. Based on the preliminary calculation model of open channel flow established in step S1, factors affecting open channel flow are obtained, and the value range of each influencing factor is selected according to the material and shape of the open channel. Combined with the ANSYS Fluent fluid simulation method, a single factor test with open channel flow as the evaluation index is completed to clarify the degree of influence on the flow; S2-3. Using Design expert analysis software and Fluent to obtain simulated flow data, a four-factor three-level response surface experiment based on open channel flow was built to screen out the first-order terms, interaction terms and quadratic terms that have a significant impact on open channel flow. Combined with variance analysis, the model correlation coefficient R was obtained. 2 =0.9905, indicating that the constructed model has good reproducibility; S2-4. Combined with response surface analysis, the water level H before the gate, the flow velocity V0 before the gate, the gate opening e and the weir height H are obtained based on the sluice-weir series regulation method. t quadratic multinomial regression model for the moderating variables; S3. Analyze the influencing factors of the preliminary open channel flow calculation model based on the sluice-weir series regulation built in step S1, fit the flow calculation model built in step S2 according to the measured data, obtain the open channel flow fitting model based on the sluice-weir series regulation mode, and bring the flow parameters in the measured data into the following flow formula to obtain the gate flow Q S : Among them, H, V0, e, H t measured by a real-time data acquisition device (101); S4. When irrigation is carried out, the real-time data acquisition device (101) obtains water flow information, the pull-wire sensor (1013) on the adjustable gate (2) collects gate opening information, and the angle sensor (1014) on the flip weir (3) collects weir height information and transmits it to the flow calculation device (2041); the flow calculation device (2041) calculates the current open channel flow Q1 according to steps S1-S3; S5. The irrigation time is obtained based on the amount of water required for farmland irrigation and the open channel flow Q1 obtained in step S4. If the irrigation time does not meet the irrigation demand, the opening of the gate and the reversing weir is adjusted to obtain the gate flow Q2 that meets the operation demand.

7. The open channel flow regulation method according to claim 6, characterized in that: The specific method of adjusting the opening of the gate and the reversing weir in step S5 includes: Adjusting the gate opening: The main control module (204) controls the motor and the motor driving device (206) of the adjustable gate (2) by using the RS485 communication method, and the motor and the motor driving device (206) drive the worm gear hoist (205), which in turn drives the screw rod (203) to drive the gate plate (201) to adjust the gate opening. Combined with the gate opening information fed back by the pull-wire sensor (1013), the gate opening information is obtained in real time, and the gate opening is adjusted until the opening requirement is met; Adjust the opening of the flip weir: the main control module (204) sends the adjusted weir height information according to the irrigation time and the irrigation water demand, and controls the hydraulic cylinder (304) to adjust the feed amount of the cylinder to complete the adjustment of the flip weir height. Combined with the information feedback of the angle sensor (1014), the weir height H is obtained in real time. t , control the hydraulic cylinder (304) to adjust the weir height until the weir height requirement is met. t Carry out secondary confirmation of irrigation flow and irrigation time to complete the main flow control process.

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