An open-channel water volume management system for farmland irrigation areas

Abstract

The present invention discloses an open-channel water volume management system for farmland irrigation areas, which relates to the field of farmland water conservancy and includes a cloud control platform, a water level detection sensor and a gate mechanism. The water level detection sensor monitors the water level changes in the upstream and downstream in real time and simultaneously collects the data of the downstream surges during the water release process. After the water release is completed, the cloud control platform controls the opening degree of the gate plate assembly to open according to the transmitted surge data and the water level difference between the upstream and downstream of the gate mechanism, and replenishes water under the condition of minimum water energy loss to make up for the total water release reduction caused by the surges, so as to achieve sufficient drainage and irrigation water volume. When discharging water, the present invention diverts the water flow so that the water flow is discharged to both sides, divides the concentrated water flow into two streams, reduces the local impact force on the downstream, and can effectively avoid the loss of the total water volume during the water release process, keeping the water volume in the irrigation area at the best level, neither too much nor too little, and having a high water release efficiency, and can effectively cope with some emergencies.

Description

Technical Field

[0001] The present invention relates to the field of farmland water conservancy, and specifically to an open-channel water volume management system for farmland irrigation areas. Background Art

[0002] When irrigation is required in a farmland irrigation area, the sluice gate of the upstream open channel is usually opened to release water, and the amount of water released is determined according to the demand of the farmland in the downstream irrigation area. Each time the sluice gate is opened to release water, in order to avoid excessive generation of surges, the opening of the sluice gate needs to be controlled step by step, which not only greatly affects the water release efficiency, but also in this case, there will still be some surges downstream, resulting in loss of the total water release volume.

[0003] When urgent water is needed in the farmland irrigation area, the traditional step-by-step control of the opening of the sluice gate will lead to very low water release efficiency. Moreover, the traditional sluice gates are opened up and down. Once the sluice gate is directly opened to release water, the powerful water flow will not only impact the sluice gate and cause damage to the sluice gate, but also impact the downstream open channel, resulting in damage to the structure of the downstream open channel. At the same time, a large amount of surges are generated, resulting in a decrease in the total water release volume, thereby affecting the irrigation downstream. Summary of the Invention

[0004] The purpose of the present invention is to provide an open-channel water volume management system for farmland irrigation areas, which can avoid loss of the total water release volume while achieving efficient water release, and at the same time can greatly reduce the scouring of the downstream open channel by the water flow, so as to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: An open-channel water volume management system for farmland irrigation areas, including a cloud control platform, a water level detection sensor and a gate mechanism. The water level detection sensors are respectively installed upstream and downstream of the gate mechanism. The gate mechanism includes a gate plate assembly having the function of controlling the upstream water release rate and diverting the water flow during water release. A flow-blocking assembly for controlling the reduction of the upstream water release potential energy according to the downstream water flow velocity is provided in the gate plate assembly. The water level detection sensors monitor the water level changes upstream and downstream in real time, and at the same time collect data on the downstream surges during the water release process. After the water release is completed, the cloud control platform controls the gate plate assembly to open the corresponding opening degree according to the transmitted surge data and the water level difference between the upstream and downstream of the gate mechanism, and replenishes water under the condition of minimum water energy loss to make up for the reduction in the total water release caused by the surges, so as to achieve sufficient drainage and irrigation water volume.

[0006] Preferably, the gate assembly includes a main frame and two gate plates. The two gate plates are installed in a triangular shape on the lower end face of the main frame. The triangular ends of the two gate plates are hinged to each other. A tail plate part is rotatably connected to the rear end of each gate plate. The upper end of the tail plate part is slidably installed on the lower end face of the main frame. An opening and closing connecting piece is installed on each tail plate part. A controllable power source is used to control the opening and closing connecting piece to move towards the center of the main frame, and the two gate plates move closer to each other. The opening distance between the tail plate part and the vertical plate part on the main frame is the opening degree of the gate. The upstream water flow is divided by the two gate plates to flow into the downstream water flow, and is guided to the openings on both sides for water discharge.

[0007] Preferably, the flow blocking assembly includes a floating member and several water blocking plates. An inner concave cavity is provided on the front side end face of the gate plate. A notch is provided on the upper end face of the gate plate at the position of the inner concave cavity. A rotating shaft is rotatably installed through the notch into the inner concave cavity. Each water blocking plate is fixedly installed on the rotating shaft. A gear is fixedly connected to the rotating shaft. A sliding groove cavity is communicated in the notch. A rack is slidably installed in the sliding groove cavity. The rack meshes with the rotating shaft. A compression spring is connected between one end of the rack and the inner side wall of the sliding groove cavity, and a steel wire rope is fixedly connected between the other end and the floating member. The floating member is placed in the downstream water flow and is impacted by the water flow of the water discharge, pulling the rack to drive the water blocking plate to flip open. The magnitude of the water flow impact is proportional to the flipping open angle of the water blocking plate.

[0008] Preferably, the opening and closing connecting piece includes a connecting block fixedly installed on the tail plate part. A connecting rod is hinged to the connecting block. A servo motor is fixedly installed on the upper end face of the main frame. The output end of the servo motor is fixedly connected to a lead screw. A threaded sleeve is threadedly connected to the lead screw. The connecting rod is hinged to the threaded sleeve. The cloud control platform issues an opening command to control the number of rotation turns of the lead screw to control the moving distance of the tail plate part.

[0009] Preferably, the water blocking plate is arc-shaped, and the width of the water blocking plate gradually increases from top to bottom.

[0010] Preferably, touch water plates are respectively installed on both sides of the floating member.

[0011] Preferably, a method for replenishing the water discharge amount due to the loss caused by downstream surges specifically includes the following steps:

[0012] S1: Send a water discharge command to the cloud control platform according to the required water volume downstream. The cloud control platform controls the gate to open and discharges the theoretical water discharge amount within time T.

[0013] S2: Use the water level detection sensor to detect the number and height of the surges generated downstream within time T. The cloud control platform calculates the actual water discharge volume based on the collected surge data, the gate data when the water release is started, and the initial water levels upstream and downstream, so as to obtain the loss of water discharge volume △V caused by the surges.

[0014] S3: After obtaining the loss of water discharge volume, dynamically control the opening of the gate for water replenishment according to the water level data upstream and downstream before water replenishment, and synchronously change the opening of the gate according to the change of the water level difference between upstream and downstream, so as to complete the water release and replenishment in the shortest time while ensuring the minimum loss of water energy.

[0015] Preferably, the method for detecting the number and height of the surges generated downstream includes the following steps:

[0016] First, extract the static water level data at least ten minutes before the gate is opened for water release as the benchmark.

[0017] Secondly, set the minimum wave crest height threshold, control the sampling frequency, identify the number of surges through wave crest detection, and finally calculate the difference between each wave crest and its adjacent wave trough to calculate the surge height, and record the maximum, average and standard deviation in time series.

[0018] Preferably, the specific method for obtaining the loss of water discharge volume △V includes the following steps:

[0019] Q1: Add a correction coefficient to the obtained average surge height as the amplitude of the downstream water level fluctuation due to the surge, and use the water level data of the downstream water level and the amplitude of the fluctuation to obtain the instantaneous value of the downstream water level.

[0020] Q2: Use the difference between the monitored upstream water level data and the instantaneous value of the downstream water level as the effective head, and then use the opened gate parameters and the effective head to obtain the instantaneous flow rate.

[0021] Q3: Perform numerical integration on the obtained instantaneous flow rate within time T to obtain the actual water discharge volume, and the difference between the theoretical water discharge volume and the actual water discharge volume is the loss of water discharge volume △V.

[0022] Preferably, the specific method for dynamically controlling the opening of the gate in step S3 includes the following:

[0023] Use the obtained loss of water discharge volume △V and the water replenishment time set according to the demand to calculate the water replenishment flow rate per unit time. Then, only need to maintain the water replenishment flow rate unchanged, and adjust the opening of the gate according to the water level difference between upstream and downstream. When the water level difference between upstream and downstream gradually decreases, gradually increase the opening of the gate.

[0024] In summary, the beneficial effects of the present invention are:

[0025] 1. The present invention diverts water through the triangular end formed by two gate plates, causing the water flow to discharge to both sides, dividing the concentrated water flow into two streams, reducing the local impact force on the downstream, avoiding damage to the structure of the downstream open channel caused by concentrated scouring, making the water flow velocity distribution more uniform after diversion, reducing the continuous erosion of high-speed water flow on specific areas, extending the service life of water conservancy facilities. At the same time, the triangular end formed by the two gate plates guides the water flow to turn gently, reducing the generation of turbulence and harmful vortices, thereby reducing energy loss and improving water flow efficiency;

[0026] 2. Moreover, when discharging water upstream, if the water flow velocity downstream is too fast, after the water retaining plate flips open, the water flow will impact into the water retaining plate, and the arc of the water retaining plate will guide the water flow to form a certain impact with the rest of the forward discharging water flow, thereby reducing the upstream water flow and avoiding too large a water flow velocity downstream;

[0027] 3. When discharging water, it is not necessary to consider the gradual opening of the gate. The opening degree of the corresponding gate can be directly opened, and the water can be discharged in the fastest way. The lost water volume is dynamically controlled to open the corresponding opening degree of the gate plate assembly according to the detected surge data and the water level difference between upstream and downstream after the water discharge ends. Thus, combined with the previous efficient water discharge method, the actual required water discharge volume can be completed in the shortest time, and the loss of total water volume during the water discharge process can be effectively avoided. Compared with the uncertainty of water volume caused by the extended opening time of the traditional delayed gate, the total water supply to the downstream can be effectively guaranteed, keeping the water volume in the irrigation area at the best level, neither too much nor too little, and with high water discharge efficiency, it can effectively respond to some emergencies. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0029] Figure 1 It is a schematic diagram of the overall structure of a water volume management system for an open channel in a farmland irrigation area according to the present invention;

[0030] Figure 2 It is a schematic diagram of the structure of a gate mechanism in a water volume management system for an open channel in a farmland irrigation area according to the present invention;

[0031] Figure 3 It is a top view structure schematic diagram of a gate mechanism in a water volume management system for an open channel in a farmland irrigation area according to the present invention;

[0032] Figure 4Schematic diagram of the rear - view mechanism of the gate mechanism in an open - channel water volume management system for farmland irrigation areas of the present invention;

[0033] Figure 5 Schematic diagram of the position structure of the component fixing block of the gate mechanism in an open - channel water volume management system for farmland irrigation areas of the present invention;

[0034] Figure 6 Schematic diagram of the gate plate structure of the gate mechanism in an open - channel water volume management system for farmland irrigation areas of the present invention;

[0035] Figure 7 Schematic diagram of the gate plate structure of the gate mechanism in an open - channel water volume management system for farmland irrigation areas of the present invention;

[0036] Figure 8 Schematic diagram of the water - retaining plate opening structure of the gate mechanism in an open - channel water volume management system for farmland irrigation areas of the present invention.

[0037] The marks in the attached drawings are described separately as follows: Gate mechanism 1; Water - level detection sensor 2; Downstream water channel 3; Upstream water channel 4; Main frame 10; Servo motor 11; Gate plate 12; Tail plate part 13; Notch 14; Rotating shaft 15; Gear 16; Rack 17; Sliding - groove cavity 18; Concave cavity 19; Water - retaining plate 20; Connecting block 21; Lead screw 22; Connecting rod 23; Threaded sleeve 24; Steel wire rope 25; Floating element 26; Water - touching plate 27; Fixing block 28. Detailed implementation mode

[0038] Now, the present invention will be further described in detail with reference to the attached drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. These attached drawings are all simplified schematic diagrams, only showing the basic structure of the present invention in a schematic way, so they only show the components related to the present invention.

[0039] To facilitate the understanding of the present invention, the present invention will be described more comprehensively with reference to the relevant attached drawings. Several embodiments of the present invention are given in the attached drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0040] All the features disclosed in this specification, or all the steps in the disclosed methods or processes, except for the mutually exclusive features and / or steps, can be combined in any way.

[0041] Any feature disclosed in this specification (including any appended claims, abstract and drawings) may be replaced by other equivalent or alternative features with a similar purpose, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is only an example of a series of equivalent or similar features.

[0042] In the present invention, unless otherwise clearly defined and limited, terms such as "installation", "connection", "coupling", "fixation" and the like shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral one; it may be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium. It may be the communication inside at least two elements or the interaction relationship between at least two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] The following is a detailed description of the present invention in conjunction with Figure 1-8 An embodiment provided by the present invention: An open channel water volume management system for a farmland irrigation area, including a cloud control platform, a water level detection sensor 2 and a gate mechanism 1. The water level detection sensor 2 is respectively installed in the upstream water channel 4 and the downstream water channel 3 to detect the water level data of the upstream and downstream. The gate mechanism 1 is installed between the upstream water channel 4 and the downstream water channel 3 to control the discharge of water from the upstream to the downstream. Since surges will be generated downstream during the opening of the gate for water discharge, and the surges will affect the water discharge volume, resulting in a decrease in the water discharge volume. The water level detection sensor 2 is used to monitor the water levels of the upstream and downstream, and at the same time collect the data of the downstream surges during the water discharge process, and transmit the data to the cloud control platform. After the water discharge is completed, the cloud control platform controls the opening degree of the gate plate assembly to open according to the transmitted surge data and the water level difference between the upstream and downstream of the gate mechanism 1, and replenishes water under the condition of minimum water energy loss to make up for the total water discharge reduction caused by the surges, so as to achieve the sufficiency of the drainage and irrigation water volume.

[0044] It is worth mentioning that in this embodiment, the gate mechanism 1 includes a gate plate assembly that controls the upstream water discharge rate and diverts the discharged water flow. The flow rate of the upstream water discharge is controlled by controlling the opening degree of the gate plate assembly. A flow blocking assembly for controlling the reduction of the upstream water discharge potential energy according to the downstream water flow velocity is provided in the gate plate assembly. Once the water flow velocity downstream is too fast during the water discharge, the flow blocking assembly will be driven to partially guide the upstream water flow back, forming a water flow impact upstream to limit the speed.

[0045] It should be noted that in this embodiment, the gate assembly includes a main frame 10 and two gate plates 12. The main frame 10 is installed across the water channel, and the two gate plates 12 are installed in a triangular shape on the lower end face of the main frame 10. The triangular ends of the two gate plates 12 are hinged to each other, so that the triangular ends of the two gate plates 12 can split the water flow. A tail plate portion 13 is rotatably connected to the rear end of each gate plate 12. The upper end of the tail plate portion 13 is slidably installed on the lower end face of the main frame 10, so that when the tail plate portion 13 slides open, the triangular ends of the two gate plates 12 will move upstream, and at the same time, the angle of the triangular ends becomes smaller, so that the larger the opening, the more obvious the effect of splitting the water flow to both sides;

[0046] An opening and closing connecting member is installed on each tail plate portion 13. A controllable power source is used to control the opening and closing connecting member to move towards the center direction of the main frame 10. The two gate plates 12 approach each other. The opening distance between the tail plate portion 13 and the vertical plate portion on the main frame 10 is the opening degree of the gate. The upstream water flow is split by the two gate plates 12 to the water flow flowing into the downstream, and is guided to the openings on both sides for water discharge.

[0047] The opening and closing connecting member includes two connecting blocks 21 fixedly installed on the tail plate portion 13. A connecting rod 23 is hinged to each connecting block 21. A servo motor 11 is fixedly installed on the upper end face of the main frame 10. The output end of the servo motor 11 is fixedly connected to a lead screw 22. A threaded sleeve 24 is threadedly connected to the lead screw 22. The connecting rod 23 is hinged to the corresponding threaded sleeve 24. When the lead screw 22 rotates clockwise, the threaded sleeve 24 located on the upper side is driven to move upward, and the threaded sleeve 24 located on the lower side is driven to move downward, so as to drive the opening and closing of the tail plate portion 13 by the up and down movement of the threaded sleeve 24. The cloud control platform issues an opening command to control the number of turns of rotation of the lead screw 22 to control the moving distance of the tail plate portion 13.

[0048] In addition, in one embodiment, the flow blocking assembly includes a buoyant member 26 and a plurality of water baffle plates 20. An inner concave cavity 19 is provided on the front side end surface of the gate plate 12. A notch 14 is provided at the position of the inner concave cavity 19 on the upper end surface of the gate plate 12. A rotating shaft 15 is rotatably installed through the notch 14 into the inner concave cavity 19. Each water baffle plate 20 is fixedly installed on the rotating shaft 15. A gear 16 is fixedly connected to the rotating shaft 15. A sliding groove cavity 18 is communicated in the notch 14. A rack 17 is slidably installed in the sliding groove cavity 18. The rack 17 meshes with the rotating shaft 15. One end of the rack 17 is connected to the inner side wall of the sliding groove cavity 18 by a compression spring, and the other end is fixedly connected to the buoyant member 26 by a steel wire rope 25. The steel wire rope 25 is fixedly guided on the gate plate 12 by a fixing block 28. At the same time, a guiding column is provided at the opening of the sliding groove cavity 18. The buoyant member 26 is placed in the downstream water flow and is impacted by the water flow of the water discharge, pulling the rack 17 to drive the water baffle plate 20 to flip open. The magnitude of the water flow impact force is proportional to the opening angle of the water baffle plate 20. Since the water flow velocity at the bottom of the water channel is lower than that on the surface, the width of the water baffle plate 20 gradually increases from top to bottom, which is convenient for the water baffle plate 20 to open. At the same time, the water baffle plate 20 can be set in an arc shape. After the water baffle plate 20 flips open, the water flow impacts into the water baffle plate 20, and the arc of the water baffle plate 20 guides the water flow to form a certain impact with the rest of the forward discharged water flow, thereby reducing the upstream water flow and avoiding excessive water flow velocity downstream. At the same time, in order to enable the buoyant member 26 to better contact the water flow effect, water contact plates 27 are respectively installed on both sides of the buoyant member 26. The water contact plates 27 can be arc-shaped, and the effect of sensing the water flow velocity is better.

[0049] When the sluice needs to be opened for water discharge, the cloud control platform receives the water discharge instruction and controls the servo motor 11 to start. The rotation of the lead screw 22 drives the threaded sleeve 24 to move upward and downward, thereby pulling the tail plate portion 13 to slide toward the center of the main frame 10, so that the sluice forms a corresponding opening degree b. The opening distances of the left and right sluice plates 12 are both b / 2. The water flow upstream is diverted by the triangular ends formed by the two sluice plates 12, so that the water flow is discharged to both sides, dividing the concentrated water flow into two strands, reducing the local impact force on the downstream, avoiding damage to the structure of the downstream open channel caused by concentrated scouring, making the water flow velocity distribution more uniform after diversion, reducing the continuous erosion of the high-speed water flow on a specific area, extending the service life of the water conservancy facilities. At the same time, the triangular ends formed by the two sluice plates 12 guide the water flow to turn gently, reducing the generation of turbulence and harmful vortices, thereby reducing energy loss and improving water flow efficiency. Moreover, when discharging water upstream, if the water flow velocity downstream is too fast, it will impact the floating part 26, causing the floating part 26 to be pulled downstream by the water flow impact force on the steel wire rope 25, thereby driving the rack 17 to slide, making the water retaining plate 20 flip open. The flipping angle of the water retaining plate 20 is proportional to the magnitude of the water flow impact force. After the water retaining plate 20 flips open, the water flow impacts into the water retaining plate 20, and the arc of the water retaining plate 20 guides the water flow to form a certain impact with the other positively discharged water flow, thereby reducing the upstream water flow and avoiding the excessive water flow velocity downstream.

[0050] When the sluice is opened to discharge water downstream, a surge will occur downstream, and the formation of the surge will cause a reduction in the total water discharge for a period of time. The traditional method is to control the sluice to open gradually to reduce the formation of the downstream surge. This method has low drainage efficiency and cannot cope with the situation of water demand. Moreover, there will still be a certain surge resulting in a reduction in the total water discharge, causing a deviation in the required water consumption downstream and affecting the growth of crops in the irrigation area. For this reason, the present invention also proposes a method for replenishing the lost water discharge caused by the surge during sluice opening. Thus, when discharging water, it is not necessary to consider the gradual opening of the sluice. The corresponding opening degree of the sluice can be opened, and the water can be discharged in the fastest and most efficient way. The lost water discharge is dynamically controlled to open the corresponding opening degree of the gate plate assembly according to the detected surge data and the water level difference between the upstream and downstream after the water discharge ends, so as to ensure the total water supply to the downstream and keep the water volume in the irrigation area optimal.

[0051] The specific method includes the following steps:

[0052] The first step:

[0053] Through the water level detection sensors 2 installed in the upstream and downstream open channels, the upstream and downstream water levels are monitored in real time by the water level detection sensors 2. When discharging water by opening the sluice, the theoretical water discharge needs to be discharged within time T according to the requirements. First, the static water level data at least ten minutes before opening the sluice downstream is extracted as the benchmark. After opening the sluice, the water level detection sensor 2 located downstream captures transient fluctuations at a sampling frequency of 20 Hz, sets the minimum wave peak height threshold, and identifies the number of surges through wave peak detection;

[0054] Finally, calculate the difference between each wave peak and its adjacent wave valley to calculate the surge height, and record the maximum, average, and standard deviation in time series;

[0055] Statistical output:

[0056] Number of surges: The number of fluctuation events exceeding the threshold per unit time;

[0057] Surge height: Record the maximum, average, and standard deviation in time series.

[0058] At the same time, the water level detection sensors 2 upstream and downstream synchronously transmit the water level data when opening the sluice to the cloud control platform, and the cloud control platform calculates the actual water discharge according to the opening degree b of the sluice when opening the sluice, so as to obtain the loss of water discharge △V caused by surges;

[0059] First, due to the surges causing fluctuations in the downstream water level, the effective head H(t) will change with time,

[0060] H(t)=h(t) 上游 -h(t) 下游 ;

[0061] And due to the existence of surges in the downstream water level, there is a fluctuating water level in the downstream. After experiments, an average surge height obtained downstream is added with a correction coefficient k, and the value of k ranges from 0.6 to 0.8, which is used as the amplitude of the water level fluctuation caused by surges in the downstream. The correction coefficient k is related to the width ratio of the water channels upstream and downstream of the sluice. The larger the width ratio of the upstream and downstream water channels, the larger the value of k, so that h(t) 下游 There is a fluctuating water level change value, so the final H(t)=h(t) 上游 -h(t) 下游 -k * average surge height;

[0062] Therefore, the actual flow rate is:

[0063]

[0064] It is: Discharge coefficient (related to the type of sluice, such as 0.6 - 0.7 for a flat gate);

[0065] b is the opening degree of the gate;

[0066] h is the water level height when flowing through the gate;

[0067] g is the acceleration due to gravity.

[0068] Therefore, finally, numerical integration of the obtained instantaneous flow rate over time T gives the actual water discharge volume.

[0069]

[0070] The lost water discharge volume △V is the theoretical water discharge volume minus the actual water discharge volume.

[0071] Step 2:

[0072] After obtaining the lost water discharge volume △V, in fact, the water discharge time can be reasonably extended according to the lost water discharge volume to supplement this part of the water volume. However, surges will still be generated during the extended water discharge time, resulting in a certain difference in the final water discharge volume. Therefore, the most efficient water discharge is selected during the first opening of the gate for water discharge, and the loss of water energy needs to be minimized during subsequent water replenishment to perfectly supplement the loss during the first water discharge, thus achieving a closed-loop of the effect.

[0073] After obtaining the lost water discharge volume △V, the opening degree of the gate is dynamically controlled according to the upstream and downstream water level data before water replenishment for water replenishment. The water discharge and replenishment are completed in the shortest time while ensuring the minimum loss of water energy. The unit time water replenishment flow rate is calculated using the obtained lost water discharge volume △V and the water replenishment time set according to the demand. Since there are no surges during water replenishment, H(t) = the upstream and downstream water level difference, and the water level difference between the upstream and downstream will not be very large after the water discharge is completed.

[0074] Therefore, the water replenishment flow rate is:

[0075]

[0076] Then, only need to maintain the water replenishment flow rate unchanged, and adjust the opening degree b of the gate according to the upstream and downstream water level differences. When the upstream and downstream water level difference gradually decreases, gradually expand the opening degree of the gate to achieve the most efficient water replenishment on the premise of maximizing the reduction of water energy loss during water replenishment.

[0077] Thus, combined with the previous efficient water discharge method, the actual required water discharge volume can be discharged in the shortest time, and the loss of the total water volume during the water discharge process can be effectively avoided. Compared with the traditional method of delaying the opening time of the gate, which leads to water volume uncertainty, the present invention effectively ensures the total water supply to the downstream, keeps the water volume for irrigation areas at the best level, neither too much nor too little, and has a high water discharge efficiency, and can effectively respond to some emergencies.

[0078] As described above, it is only the specific implementation manner of the invention, but the protection scope of the invention is not limited thereto. Any changes or substitutions that can be thought of without creative efforts should be covered within the protection scope of the invention. Therefore, the protection scope of the invention should be subject to the protection scope defined by the claims.

Claims

1. An open-channel water volume management system for farmland irrigation areas, comprising a cloud control platform, a water level detection sensor (2) and a gate mechanism (1), wherein the water level detection sensors (2) are respectively installed upstream and downstream of the gate mechanism (1), and is characterized in that: The gate mechanism (1) includes a gate plate assembly that controls the upstream water discharge rate and diverts the discharged water flow. A flow-blocking assembly for controlling the reduction of the upstream water discharge potential energy according to the downstream water flow velocity is provided in the gate plate assembly. The water level detection sensor (2) monitors the water level changes in the upstream and downstream in real time and simultaneously collects data on the downstream surges during the water discharge process. After the water discharge is completed, the cloud control platform controls the gate plate assembly to open a corresponding opening degree according to the transmitted surge data and the water level difference between the upstream and downstream of the gate mechanism (1), and replenishes water under the condition of minimum water energy loss to make up for the total reduction in water discharge caused by the surges, so as to achieve sufficient drainage and irrigation water volume. The flow-blocking assembly includes a floating member (26) and a plurality of water-blocking plates (20). An inner concave cavity (19) is provided on the front side end surface of the gate plate (12). A notch (14) is provided at the position of the inner concave cavity (19) on the upper end surface of the gate plate (12). A rotating shaft (15) is rotatably installed through the notch (14) into the inner concave cavity (19). Each water-blocking plate (20) is fixedly installed on the rotating shaft (15). A gear (16) is fixedly connected to the rotating shaft (15). A chute cavity (18) is communicated in the notch (14). A rack (17) is slidably installed in the chute cavity (18). The rack (17) meshes with the rotating shaft (15). One end of the rack (17) is connected to the inner side wall of the chute cavity (18) by a compression spring, and the other end is fixedly connected to the floating member (26) by a steel wire rope (25). The floating member (26) is placed in the downstream water flow and is impacted by the discharged water flow, pulling the rack (17) to drive the water-blocking plate (20) to flip open. The magnitude of the water flow impact force is proportional to the flipping open angle of the water-blocking plate (20).

2. The open channel water volume management system for farmland irrigation areas according to claim 1, wherein: The gate plate assembly includes a main frame (10) and two gate plates (12). The two gate plates (12) are installed in a triangular shape on the lower end surface of the main frame (10). The two gate plates (12) are hinged to each other near the triangular ends. A tail plate portion (13) is rotatably connected to the rear end of each gate plate (12). The upper end of the tail plate portion (13) is slidably installed on the lower end surface of the main frame (10). An opening and closing connecting member is installed on each tail plate portion (13). A controllable power source is used to control the opening and closing connecting member to move towards the center direction of the main frame (10), and the two gate plates (12) move closer to each other. The opening distance between the tail plate portion (13) and the main frame (10) is the opening degree of the gate. The upstream water flow is diverted through the two gate plates (12) to the water flowing into the downstream, and is guided to the openings on both sides for water discharge.

3. The open channel water volume management system for farmland irrigation areas according to claim 2, characterized in that: The opening and closing connecting member includes a connecting block (21) fixedly installed on the tail plate portion (13). A connecting rod (23) is hinged to the connecting block (21). A servo motor (11) is fixedly installed on the upper end face of the main frame (10). The output end of the servo motor (11) is fixedly connected to a lead screw (22). A threaded sleeve (24) is threadedly connected to the lead screw (22). The connecting rod (23) is hinged to the threaded sleeve (24). The cloud control platform issues an opening instruction to control the number of turns of rotation of the lead screw (22) to control the moving distance of the tail plate portion (13).

4. The open channel water volume management system for farmland irrigation areas according to claim 3, characterized in that: The water baffle (20) is arranged in an arc shape, and the width of the water baffle (20) gradually increases from top to bottom.

5. The open channel water volume management system for farmland irrigation areas according to claim 4, characterized in that: Touch water plates (27) are respectively installed on both sides of the float member (26).

6. The open channel water volume management system for farmland irrigation areas according to claim 1, characterized in that: A method for replenishing water for the water discharge loss caused by surges specifically includes the following steps: S1: Send a water discharge instruction to the cloud control platform according to the water demand of the downstream. The cloud control platform controls the gate to open and discharges the theoretical water discharge amount within time T. S2: Use a water level detection sensor to detect the number of surges and the surge height generated downstream within time T. The cloud control platform calculates the actual water discharge amount based on the collected surge data, the gate data when the water discharge is started, and the initial water levels of the upstream and downstream, so as to obtain the water discharge loss amount △V caused by surges. S3: After obtaining the loss of water discharge amount, dynamically control the opening degree of the gate for water replenishment according to the water level data of the upstream and downstream before water replenishment. Synchronously change the opening degree of the gate according to the change of the water level difference between the upstream and downstream, and complete the water discharge and replenishment in the shortest time while ensuring the minimum loss of water energy.

7. The open-channel water volume management system for farmland irrigation areas according to claim 6, characterized in that: A method for detecting the number of surges and the surge height generated downstream includes the following steps: First, extract the static water level data at least ten minutes before the gate is opened for water discharge as a reference. Secondly, set a minimum wave peak height threshold, control the sampling frequency, and identify the number of surges through wave peak detection. Finally, calculate the difference between each wave peak and its adjacent wave valley to calculate the surge height, and record the maximum surge height and the average surge height in time series.

8. A water volume management system for open channels in a farmland irrigation area according to claim 7, characterized in that: The specific method for obtaining the loss of water discharge amount △V includes the following steps: Q1: Add a correction coefficient to the obtained average surge height as the amplitude of the downstream water level fluctuating due to surges. Use the water level data of the downstream water level and the amplitude of the fluctuation to obtain the instantaneous value of the downstream water level. Q2: Use the difference between the monitored upstream water level data and the instantaneous value of the downstream water level as the effective head, and then use the opened gate parameters and the effective head to obtain the instantaneous flow rate. Q3: Perform numerical integration on the obtained instantaneous flow rate within time T to obtain the actual water discharge amount. The difference between the theoretical water discharge amount and the actual water discharge amount is the loss of water discharge amount △V.

9. The open-channel water volume management system for farmland irrigation areas according to claim 8, characterized in that: In step S3, dynamically controlling the opening degree of the gate specifically includes the following method: Calculate the water replenishment flow rate per unit time by using the obtained loss of water discharge amount △V and the water replenishment time set according to the demand. Then, only need to maintain the water replenishment flow rate unchanged, and adjust the opening degree of the gate according to the water level difference between the upstream and downstream. When the water level difference between the upstream and downstream gradually decreases, gradually increase the opening degree of the gate.

Images