Constant flow water discharge weir and constant flow water discharge method based on automatic control

Abstract

The present invention provides a constant flow water discharge weir based on automatic control and a constant flow water discharge method thereof, which relates to the technical field of water level control facilities, and comprises a weir plate slidably arranged in a base, a lifting device and a displacement sensor are connected to the weir plate, the lifting device is driven by a motor, the motor and the displacement sensor are electrically connected to a controller, and a water level signal collector is electrically connected to the controller; the lifting device comprises a rack vertically fixed on the weir plate and a gear meshing with the rack, and the gear is driven to rotate by the motor. The problem that it is difficult for water retaining and water discharge facilities in the prior art to ensure a constant water flow is solved.

Description

Technical Field

[0001] The invention relates to the technical field of water level control facilities, in particular to a constant flow water discharge weir based on automatic control. Background Art

[0002] The common water retaining and water discharge facilities in the prior art are mostly artificial or mechanical weir plates. According to the upstream water volume and the downstream water volume requirements, mechanical equipment is used to roughly adjust the weir plate opening to control the water discharge flow. During the water discharge process, the outflow process fluctuates with the inflow process, and it is difficult to ensure the constancy of the outflow process. This is for application scenarios with high requirements for downstream flow processes, such as urban landscape water systems, scenic area water networks, large-scale beach water replenishment and salt washing, farmland irrigation, sewage discharge, etc. There will be supply and demand imbalances, water level information lags behind regulation needs, and real-time regulation is difficult. Summary of the invention

[0003] In view of the above problems in the prior art, the present invention provides a constant flow water discharge weir based on automatic control, which solves the problem that the water retaining and discharge facilities in the prior art are difficult to ensure a constant water flow rate.

[0004] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is as follows:

[0005] Provided is a constant-current water discharge weir based on automatic control, which comprises a weir plate slidably arranged in a base, a lifting device and a displacement sensor are connected to the weir plate, the lifting device is driven by a motor, the motor and the displacement sensor are electrically connected to a controller, a water level signal collector is electrically connected to the controller, and a collection point of the water level signal collector is located in a wave stabilization box; the lifting device comprises a rack vertically fixed on the weir plate and a gear meshing with the rack, and the gear is driven to rotate by the motor.

[0006] Furthermore, the water level signal collector is an ultrasonic water level meter. The ultrasonic water level meter does not contact the water surface, is installed directly above the water surface, has no requirements for water quality, is easy to install and maintain, and has accurate measurement data, which can improve the accuracy and service life of the constant flow water discharge weir.

[0007] Furthermore, the water level signal collector is fixed above the water level to be measured through a support frame, and a solar power supply box for supplying power to the water level signal collector is fixed on the support frame. The water level signal collector is powered by solar energy, which is self-sufficient and does not require manual regular replacement of batteries, thereby reducing manual maintenance costs.

[0008] Furthermore, a wind speed and direction sensor is also provided on the support frame, and the wind speed and direction sensor is electrically connected to the controller. The wind speed and direction sensor is used to eliminate the controller's misjudgment caused by the influence of wind on the water level.

[0009] Furthermore, the wave stabilization box includes a connecting part placed in the water and a windshield part located on the water surface, the top surface of the windshield part is open and located below the water level signal collector, and a connecting hole for water to flow in is provided on the side wall of the connecting part. Water outside the connecting part is introduced into the inner cavity through the connecting hole to form a communicating vessel, so that the water level inside the connecting part is consistent with the water level outside, and the windshield part provides a barrier for the water inside the connecting part, reduces the water surface fluctuation caused by natural environment such as wind speed, reduces the misoperation of the weir plate, and improves reliability.

[0010] Furthermore, a wireless communication module is provided between the water level signal collector and the controller. The water level signal collected by the water level signal collector is transmitted to the controller through the wireless communication module, which reduces the requirements for the spatial layout between the controller and the water level signal.

[0011] Furthermore, the collection frequency of the water level signal collector is 1 to 50 times per second.

[0012] Furthermore, the controller controls the motor to operate at a frequency of 5 to 10 minutes per time.

[0013] Furthermore, the base is arranged on both sides of the weir plate, and a rectangular groove is arranged on the base for the weir plate to be inserted and slide vertically, and a roller is arranged between the rectangular groove and the weir plate. The roller can reduce the friction between the base and the weir plate and improve the transmission efficiency.

[0014] Furthermore, one side of the weir plate passes through the base and is fixedly connected to the rack.

[0015] Furthermore, the weir plate is a thin-walled weir. A thin-walled weir refers to a weir whose ratio of the weir top thickness to the water head on the weir is less than 0.67. The weir top wall of the thin-walled weir has only one edge contact with the water flow passing through the weir, has no effect on the water flow, has a stable relationship between the water head and the flow, and reduces the effect of the weir plate on the water flow during the up and down sliding process.

[0016] The above-mentioned constant flow water discharge method based on the automatic control constant flow water discharge weir comprises the following steps:

[0017] S1: Determine the water head value H on the demand weir according to the demand water flow Q downstream of the release weir;

[0018] S2: Calculate the initial position L0 of the weir plate according to the selected weir plate type and the required water head value H on the weir;

[0019] S3: Install a constant flow water discharge weir based on automatic control, place the wave stabilization box 3 to 5H upstream of the weir plate, and make the weir plate at the L0 position;

[0020] S4: monitor the current water level in front of the weir in the wave stabilization box in real time through the water level signal collector and transmit it to the controller;

[0021] S5: On the controller side, according to the received current water level in front of the weir, the control parameters of the controller are adjusted, and the lifting device is controlled by the controller to drive the weir plate to move up and down;

[0022] S6: During the up and down movement of the weir plate, the displacement of the weir plate is collected in real time by the displacement sensor and fed back to the controller. The controller determines whether the displacement of the weir plate reaches the target movement, thereby keeping the current water head on the weir at a constant set value.

[0023] Furthermore, the method for eliminating the influence of wind speed on water level in the above method includes:

[0024] The wind speed and direction sensor is used to monitor the wind direction and speed in real time. The wind speed is V, and the wind direction θ is the angle between the wind direction and the outflow direction of the weir, that is, the outflow direction velocity V1 = V cosθ. The wind level is obtained based on V1, and then the corresponding wave height H is queried, that is, the compensation head on the weir is H 浪 , the conversion coefficient is k, and the weir outflow is corrected to

[0025] Furthermore, the method for obtaining the initial position L0 of the weir plate in the above step S2 is:

[0026] According to the selected weir plate type, the vertical height d of the weir on the weir plate is obtained.

[0027] Determine whether setting a weir can satisfy H <d,

[0028] If not satisfied, set up two weirs for judgment, Q = ∑ (Q1 + Q2), H1 = H2 <d

[0029] If it is still not satisfied, continue to increase the number of weirs until the water head H on a single weir is i <d,

[0030] Subtract H from the water level when setting the weir plate i That is, the position of the bottom end of the weir is obtained, and the initial position L0 of the weir plate is obtained through the position of the bottom end of the weir.

[0031] The beneficial effects of the present invention are: the water level information is collected in real time by the water level signal collector, and the water level information is fed back to the controller, and the motor action is controlled after processing and judgment by the controller. When the motor rotates forward, the gear drives the rack to move to move the weir plate upward, and when the motor rotates reversely, the weir plate is driven down, thereby adjusting the water head on the weir, controlling the water flow rate, and keeping the water flow rate constant.

[0032] The displacement sensor can feed back the displacement of the weir plate to the controller in real time, so that the controller can obtain the displacement of the weir plate in real time, avoid excessive or insufficient movement, and improve the accuracy of moving the weir plate.

[0033] The transmission method of gear-driven rack is adopted between the motor and the weir plate to convert the rotation of the motor into the vertical movement of the weir plate. The gear rack transmission has a large bearing capacity and can improve the reliability of the transmission; the gear rack has a fast transmission speed and the transmission ratio can be precisely controlled, which reduces the control difficulty of the controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the circuit connection block diagram of the controller in the constant flow water discharge weir based on automatic control.

[0035] Figure 2 It is a top view of the assembly point of the base and the weir plate.

[0036] Figure 3 for Figure 2 Cross-sectional view at AA in the middle.

[0037] Figure 4 for Figure 2 Cross-sectional view at the middle BB.

[0038] Figure 5 This is the installation diagram of the water level signal collector.

[0039] Among them, 1. base; 11. rectangular groove; 12. roller; 2. weir plate; 3. gear; 4. rack; 5. water level signal collector; 51. ultrasonic water level meter; 52. support frame; 53. solar power supply box; 531. solar panel; 6. displacement sensor; 7. wave stabilization box; 71. connecting part; 711. connecting hole; 72. wind shield. DETAILED DESCRIPTION

[0040] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0041] The constant flow water discharge weir based on automatic control comprises a weir plate 2 slidably arranged in a base 1, a lifting device and a displacement sensor are connected to the weir plate 2, and the lifting device is driven by a motor, such as Figure 1 As shown, the motor and the displacement sensor are electrically connected to the controller, and the controller is electrically connected to a water level signal collector 5, and the collection point of the water level signal collector is located in a stabilizing box 7; the lifting device includes a rack 4 vertically fixed on the weir plate 2 and a gear 3 meshing with the rack 4, and the gear 3 is driven to rotate by the motor.

[0042] The wave stabilization box 7 includes a connecting portion 71 placed in the water and a wind shielding portion 72 located on the water surface, the top surface of the wind shielding portion 72 is open, and a connecting hole 711 for water to flow in is provided on the side wall of the connecting portion 71. The connecting portion 71 is truncated cone-shaped, and the wind shielding portion 72 is cylindrical, and the insides of the connecting portion 71 and the wind shielding portion 72 are both hollow.

[0043] The interior of the wave stabilization box 7 forms a communicating vessel with the external water body, so that the internal and external liquid levels are at the same height. The wind shielding function of the wind shield 72 can eliminate the instantaneous impact of external wind on the water surface fluctuation to the greatest extent, maintain the water level inside the wave stabilization box constant, that is, maintain the water head on the weir stable, and minimize the error.

[0044] The working principle of the present invention is: the water level signal, i.e., the height of the water level, is collected in real time by a water level signal collector, and after the collected signal is converted into analog / digital, it is transmitted to a controller at a certain distance from the water level signal collector through a wireless communication module, and the collected water level change value is converted into the number of revolutions required for the motor to rotate by the controller, and output in the form of a digital signal and transmitted to the motor through digital-analog conversion, the motor receives the signal to rotate, and drives the rack 4 to rise or fall through the gear 3, thereby driving the weir plate 2 to rise or fall. The controller is set in a control room, which is located on the shore next to the weir plate 2, and the motor is installed next to the weir plate 2, and AC power is drawn from the control room to drive the motor to rotate.

[0045] The present invention is further described in detail below with reference to specific embodiments.

[0046] Example 1

[0047] A constant flow water discharge weir based on automatic control comprises a weir plate 2 slidably arranged in a base 1. The weir plate 2 is a plate-shaped member for intercepting water or controlling water flow. The material of the weir plate 2 is usually PVC, fiberglass or stainless steel, and the wall thickness can be increased to withstand large flow water areas.

[0048] The weir plate 2 is connected with a lifting device and a displacement sensor, and the preferred model of the displacement sensor is MPS-M-1500MM-P-AB. The lifting device is driven by a motor, and the motor and the displacement sensor are electrically connected to the controller, and the controller is electrically connected to a water level signal collector 5. The displacement sensor collects the movement displacement of the weir plate 2 and transmits it to the controller so that the controller can perform the next action. If the displacement of the weir plate 2 is equal to the change in the water level, the operation of the motor is stopped; if the displacement of the weir plate 2 is greater than the change in the water level, the motor is controlled to reverse and the displacement sensor is detected at the same time until the displacement is equal to the change in the water level; if the displacement of the weir plate 2 is less than the change in the water level, the motor is controlled to continue to be active until the displacement is equal to the change in the water level.

[0049] The lifting device is used to convert the rotary motion of the motor into reciprocating linear motion in the vertical direction of the weir plate 2. In the field of mechanics, the lifting devices that can achieve this function usually include a bidirectional screw mechanism, a crank slider mechanism, a worm gear mechanism, and a rack and pinion transmission mechanism. Since the weir plate 2 is located in the water, for the convenience of control, the control room is usually set on the land next to the weir plate. Considering the spatial layout, implementation possibility and convenience, a rack and pinion transmission mechanism is selected as the lifting device in this embodiment.

[0050] The lifting device includes a rack 4 vertically fixed on the weir plate 2 and a gear 3 meshing with the rack 4, and the gear 3 is driven to rotate by a motor. Usually, the motor has a high speed, and a reducer is connected between the motor and the gear 3 to reduce the speed of the motor.

[0051] Example 2

[0052] This embodiment is further optimized based on the embodiment 1, and the water level signal collector 5 is an ultrasonic water level meter, and the preferred model is an ultrasonic water level meter of the YDZ-YL9 series. This series of ultrasonic water level meters adopts digital signal processing technology, has high precision, can accurately detect changes in water levels, and has a wide coverage range of the generated ultrasonic beam, which can avoid misoperation caused by local water level changes caused by water waves caused by the natural environment, and has strong anti-interference ability, and is suitable for complex measurement environments.

[0053] Example 3

[0054] This embodiment is further optimized based on embodiment 2. Figure 5 As shown, the water level signal collector 5 is fixed above the water level to be measured through a support frame 52, and a solar power supply box 53 for supplying power to the water level signal collector 5 is fixed on the support frame, and the solar power supply box 53 is connected to a solar panel 531 fixed on the support frame 52. A wind speed and direction sensor is installed at the bottom end of the support frame, and the preferred model is an RS485 digital 360° wind speed sensor.

[0055] A solar power generation device and a battery are installed in the solar power supply box 53 . The solar panel 531 collects sunlight and converts the solar energy into electrical energy through the solar power generation device and stores it in the battery. The battery is used to power the ultrasonic water level meter 51 .

[0056] A space for placing spare batteries is reserved in the solar power supply box 53, which is used to power the ultrasonic water level meter 51 by manually placing charged batteries when solar energy is insufficient, so as to ensure the continuous operation of the ultrasonic water level meter 51.

[0057] Example 4

[0058] This embodiment is further optimized based on embodiment 1 or 2, and a wireless communication module is provided between the water level signal collector and the controller. The water level signal collected by the water level signal collector is transmitted to the controller through the wireless communication module, which reduces the requirements for the spatial layout between the controller and the water level signal. The controller adopts an STM32 single-chip microcomputer, and the wireless communication module is one or more of a WIFI module / GPRS module. The STM32 single-chip microcomputer is an embedded single-chip microcomputer with low cost and meets the design requirements.

[0059] Example 5

[0060] This embodiment is further optimized based on the first embodiment. The acquisition frequency of the water level signal collector is 1 to 50 times per second, which can ensure the real-time nature of the collected signal and avoid the waste of power consumption caused by too frequent signal acquisition. The controller controls the motor to move at a frequency of 5 to 10 minutes per time. Avoid unnecessary loss caused by too frequent movement of the motor and reduce the service life.

[0061] Example 6

[0062] This embodiment is further optimized based on embodiment 1. Figure 2 to Figure 4 As shown, the base 1 is arranged on both sides of the weir plate 2, and a rectangular groove 11 is arranged on the base 1 for the weir plate 2 to be inserted and slide vertically, and a roller 12 is arranged between the rectangular groove 11 and the weir plate 2. The base 1 is only arranged on both sides of the weir plate 2, which reduces the material used for the base 1 and the difficulty of installation. The rectangular groove 11 is used to limit the weir plate 2. The roller 12 is rotatably connected to the base 1, and the opposite surfaces of the weir plate 2 and the rectangular groove 11 are in contact through the roller surface of the roller 12, and the sliding friction between the weir plate 2 and the rectangular groove 11 is converted into rolling friction through the roller 12, thereby improving the transmission efficiency.

[0063] Example 7

[0064] This embodiment is further optimized based on embodiment 6. As shown in embodiment 4, one side of the weir plate 2 passes through the base 1 and is fixedly connected to the rack 4. The connection between the rack 4 and the gear 3 is arranged outside the base 1, which is convenient for the installation of the motor and the displacement sensor and the observation of the entire transmission process, and is convenient for inspection and maintenance.

[0065] Example 8

[0066] The weir plate 2 is a thin-walled weir. A thin-walled weir is a weir whose ratio of the weir top thickness to the water head on the weir is less than 0.67. The weir top wall of the thin-walled weir has only one edge contact with the water flow passing through the weir, which has no effect on the water flow. It has a stable relationship between the water head and the flow rate, and reduces the effect of the weir plate 2 on the water flow during the up and down sliding process.

[0067] In this embodiment, the weir plate 2 is preferably a right-angled triangle thin-walled weir. Figure 5As shown, a notch with a right-angled triangle cross section is provided at the top of the weir plate 2. The flow calculation formula of the right-angled triangle thin-wall weir is:

[0068] Q=1.4H 2.5

[0069] Where Q is the flow rate and H is the water head above the weir.

[0070] The water head H on the weir is constant, which can ensure that the discharge flow Q is constant.

[0071] When the weir plate 2 adopts a right-angle triangular weir, the constant flow water discharge method based on the automatic control constant flow water discharge weir comprises the following steps:

[0072] S1: Determine the water head value H on the demand weir according to the demand water flow Q downstream of the release weir. The specific calculation method is:

[0073] According to the formula Q = 1.4H 2.5 Calculate the H value,

[0074] If H = 0.021 ~ 0.200m, use this H value;

[0075] If H = 0.301 ~ 0.350m, then use the formula Q = 1.343H 2.47 Calculated H value;

[0076] If H = 0.021 ~ 0.300m, the average value of H calculated by the above two formulas is used.

[0077] S2: According to the structural characteristics of the right-angled triangular weir, the angle between the two slopes of the right-angled triangular weir is 90°, and the vertical height d of the weir and the maximum width a at the top of the weir are in a relationship of a=2d;

[0078] Determine whether setting a weir can satisfy H <d,

[0079] If not satisfied, set up two weirs for judgment, Q = ∑ (Q1 + Q2), H1 = H2 <d

[0080] If it is still not satisfied, continue to increase the number of weirs until H on a single weir is i <d,

[0081] H on each weir i are equal, H i is the height between the water surface and the bottom of the weir. The bottom of the weir is fixed on the weir plate 2. A certain H i An initial position L0 of the weir plate 2 can be uniquely determined.

[0082] S3: Install a constant flow water discharge weir based on automatic control, connect the top of the wave stabilization box to the support frame where the ultrasonic water level meter is installed through a rod, and the wave stabilization box provides a barrier from wind to the water level below the ultrasonic water level meter. The inner diameter of the wave stabilization box must be larger than the detection range of the ultrasonic water level meter, and the wave stabilization box is placed 3 to 5H upstream of the weir plate;

[0083] The motor is started manually, and the motor drives the gear 3 to rotate, so that the weir plate 2 is adjusted to the initial position L0.

[0084] S4: monitor the current water level in front of the weir in the wave stabilization box in real time through an ultrasonic water level meter and transmit it to the controller;

[0085] S5: On the controller side, a water level change value is obtained by comparing the received current water level in front of the weir with the initial water level value. If the value is positive, the lifting device is controlled to drive the weir plate to move upward by the change distance of the water level; if the water level change value is negative, the lifting device is controlled to drive the weir plate to move downward by the change distance of the water level.

[0086] When the water level rises, the water head value on the weir is greater than the set value, and the controller needs to control the motor to drive gear 3 to rotate clockwise ( Figure 4 ), the weir plate 2 moves upward, and the displacement sensor collects the displacement of the weir plate 2 in real time until the moving distance of the weir plate 2 is equal to the rising distance of the water level, so that the current water head on the weir is always kept at a constant set value, thereby ensuring the constant discharge flow rate;

[0087] When the water level drops, the water head value on the weir is less than the set value, and the controller needs to control the motor to drive gear 3 to rotate counterclockwise ( Figure 4 The weir plate 2 is moved downwards, and the displacement sensor collects the displacement of the weir plate 2 in real time until the movement distance of the weir plate 2 is equal to the drop distance of the water level, so that the current water head on the weir is always kept at a constant set value, thereby ensuring the constant discharge flow rate.

[0088] The methods for eliminating the influence of wind speed on water level in the above methods include:

[0089] The wind speed and direction sensor is used to monitor the wind direction and speed in real time. The wind speed is V, and the wind direction θ is the angle between the wind direction and the outflow direction of the weir, that is, the outflow direction velocity V1 = Vcosθ. The wind level is obtained based on V1, and then the corresponding wave height H is queried, that is, the compensation head on the weir is H 浪 , the conversion coefficient is k, and the weir outflow is corrected to

[0090] During the operation of this water discharge weir, the ultrasonic water level meter and wind speed and direction sensor monitor the external signals, which are then transmitted to the controller. The control room outputs signals based on the water level fluctuations in front of the weir and the wind direction and speed conditions, and then controls the rotation of the stepper motor to maintain a constant outflow.

Claims

1. A constant flow water discharge weir based on automatic control, characterized in that: It comprises a weir plate slidably arranged in a base, a lifting device and a displacement sensor are connected to the weir plate, the lifting device is driven by a motor, the motor and the displacement sensor are electrically connected to a controller, the controller is electrically connected to a water level signal collector, and the collection point of the water level signal collector is located in a wave stabilization box; the water level signal collector is an ultrasonic water level meter; the wave stabilization box comprises a connecting part placed in the water and a wind shield part located on the water surface, the top surface of the wind shield part is open and located below the water level signal collector, and a connecting hole for water to flow in is arranged on the side wall of the connecting part; The lifting device comprises a rack vertically fixed on the weir plate and a gear meshing with the rack, and the gear is driven to rotate by the motor; The water level signal collector is fixed above the water level to be measured through a support frame, and a solar power supply box for supplying power to the water level signal collector is fixed on the support frame; The support frame is also provided with a wind speed and direction sensor, and the wind speed and direction sensor is electrically connected to the controller.

2. The constant flow water discharge weir based on automatic control according to claim 1 is characterized in that: A wireless communication module is provided between the water level signal collector and the controller.

3. The constant flow water discharge weir based on automatic control according to claim 1, characterized in that: The base is arranged on both sides of the weir plate, and a rectangular groove for the weir plate to be inserted and vertically slide is arranged on the base, and a roller is arranged between the rectangular groove and the weir plate.

4. A constant flow water discharge method based on an automatically controlled constant flow water discharge weir according to any one of claims 1 to 3, comprising the following steps: S1: Determine the water head value H on the demand weir according to the demand water flow Q downstream of the release weir; S2: The initial position of the weir is calculated based on the selected weir type and the required water head value H on the weir. ; S3: Install a constant flow weir based on automatic control, place the wave stabilization box 3~5H upstream of the weir plate, and make the weir plate Location; S4: monitor the current water level in front of the weir in the wave stabilization box in real time through the water level signal collector and transmit it to the controller; S5: On the controller side, according to the received current water level in front of the weir, the control parameters of the controller are adjusted, and the lifting device is controlled by the controller to drive the weir plate to move up and down; S6: During the up and down movement of the weir plate, the displacement of the weir plate is collected in real time by the displacement sensor and fed back to the controller. The controller determines whether the displacement of the weir plate reaches the target movement, thereby keeping the current water head on the weir at a constant set value.

5. The constant flow water discharge method based on the automatic controlled constant flow water discharge weir according to claim 4, characterized in that: Methods to eliminate the effect of wind speed on water level include: The wind speed and direction sensor is used to monitor the real-time wind direction and speed. The wind speed is V, and the wind direction θ is the angle between the wind direction and the outflow direction of the weir, that is, the outflow direction velocity , according to V1, the wind level is obtained, and then the corresponding wave height H is queried, that is, the compensation head on the weir is , the conversion coefficient is k, and the weir outflow is corrected to .

6. The constant flow water discharge method based on the automatic controlled constant flow water discharge weir according to claim 5, characterized in that: The initial position of the weir plate is obtained in step S2. The method is: According to the selected weir plate type, the vertical height d of the weir on the weir plate is obtained. Determine whether setting a weir can satisfy H <d, If it is not satisfied, two weirs are set for judgment. , If it is still not satisfied, continue to increase the number of weirs until the water head on a single weir is <d, Subtract the water level when setting the weir plate That is, the position of the bottom of the weir is obtained, and the initial position of the weir plate is obtained through the position of the bottom of the weir. .

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