A test and calibration system for flow meters in drainage pipes

Abstract

This utility model discloses a flow meter testing and calibration system for drainage pipelines, relating to the field of flow meter calibration technology. It includes: a simulated water tank with a track along it; a track vehicle slidably mounted on the track, comprising a track vehicle chassis and an L-shaped support, one end of which is hinged to the track vehicle chassis via an electric turntable; a hydraulic cylinder is also provided between the L-shaped support and the electric turntable, with its extension / retraction end hinged to one end of the L-shaped support; a servo motor driven by the track vehicle chassis; a fork plate positioned at the other end of the L-shaped support; and a data acquisition controller that acquires the track vehicle's moving speed and the measurement data of the flow meter under test, and performs calibration adjustments based on both data. This calibration system can improve the accuracy of flow meter measurement data.

Description

Technical Field

[0001] This utility model belongs to the field of flow meter calibration technology, and more specifically, relates to a flow meter testing and calibration system for drainage pipelines. Background Technology

[0002] Drainage pipe networks suffer from problems such as large pipe diameters, high flow velocities, high suspended solids concentrations, numerous impurities, and sludge deposition, making flow meters susceptible to obstruction or interference. For example, ultrasonic flow meters experience accuracy degradation in fluids containing large amounts of air bubbles or suspended solids; Doppler flow meters require regular maintenance to prevent obstruction by foreign objects; and electromagnetic flow meters rely on fluid conductivity, require sufficient straight pipe length, and are easily corroded by sludge. Flow monitoring necessitates the simultaneous acquisition of liquid level, flow velocity, and water volume data, but the following issues exist in actual pipe networks: 1. Insufficient model iteration: Insufficient accumulation of laboratory and field data affects the accuracy of mathematical models; 2. High installation difficulty: Large-diameter pipes require submersible construction, and manhole maintenance intervals are short; 3. Environmental interference: Gas interference, flow velocity fluctuations, etc., lead to decreased data stability. Due to these problems, enhanced data calibration is needed to improve the accuracy and reliability of flow meter testing. Utility Model Content

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a flow meter testing and calibration system for drainage pipelines. This system involves setting up a track beside a simulated water tank, on which a track vehicle capable of moving at a constant speed is mounted. The track vehicle, via an L-shaped bracket, allows the flow meter under test to be submerged in the simulated water. As the track vehicle moves along the track, the data acquisition controller obtains the track vehicle's speed and the flow meter's measurement data. By comparing these two sets of data, the controller can calibrate and adjust the flow meter, thereby improving the accuracy of the flow meter's measurement data.

[0004] To achieve the above objectives, this utility model provides a test and calibration system for a drainage pipeline flow meter, comprising: A simulated pool with tracks running along its edge; A railcar is slidably mounted on the rail. The railcar includes a railcar chassis and an L-shaped support. One end of the L-shaped support is hinged to the railcar chassis via an electric turntable. A hydraulic cylinder is also provided between the L-shaped support and the electric turntable. The telescopic end of the hydraulic cylinder is hinged to one end of the L-shaped support. A servo motor is connected to the drive unit of the railcar chassis. A fork plate is set at the other end of the L-shaped bracket. When the flow meter is calibrated, the flow meter under test on the fork plate is submerged below the liquid surface of the simulated water tank. An acquisition controller collects the moving speed of the rail car and measurement data of the flowmeter to be tested, and verifies and adjusts the flowmeter to be tested according to the two sets of data.

[0005] Preferably, the rail is arranged along the length direction of the simulated pool, and driven by the servo motor, the rail car drives the flowmeter to be tested to perform uniform linear motion along the rail through the L-shaped bracket.

[0006] Preferably, the cross section of one end of the L-shaped bracket is in a Japanese shape, the bottom cross beam of the L-shaped bracket is connected with the rotating part of the electric turntable through a hinge shaft, the middle cross beam of the L-shaped bracket is connected with the telescopic end of the oil cylinder, and the fixed end of the oil cylinder is connected with the rotating part of the electric turntable through an oil cylinder support.

[0007] Preferably, the rotating part of the electric turntable is further provided with a left frame and a right frame, a rectangular frame groove is formed between the left frame and the right frame, and the rectangular frame groove matches the shape of one end of the L-shaped bracket.

[0008] Preferably, the other end of the L-shaped bracket is provided with a telescopic rod, the other end of the L-shaped bracket is connected with one end of the telescopic rod through a telescopic cylinder, and the other end of the telescopic rod is connected with the fork plate.

[0009] Preferably, the acquisition controller is arranged on the rotating part of the electric turntable, and the acquisition controller is located at the hinged end of the L-shaped bracket.

[0010] Preferably, the fork plate comprises a plurality of branch parts, and each branch part can be connected with the flowmeter to be tested.

[0011] Preferably, the bottom of the simulated pool is a semicircular tubular groove.

[0012] Preferably, the fixed part of the electric turntable is connected with the chassis of the rail car.

[0013] The utility model provides a test and verification system for a drainage pipeline flowmeter, and its beneficial effects are as follows: (1) The test and verification system protected by the utility model breaks the traditional thinking stereotype that a standard flow field must be created in water flow to calibrate a flowmeter. By constructing a static water body (test pool) and a bearing platform (rail car) that performs high-precision uniform linear motion therein, the problem of "measuring water flow velocity" is skillfully converted into the problem of "measuring the velocity of an object moving uniformly in static water", which is easier to accurately control and measure. This system architecture is the cornerstone of the present solution, which enables high-precision and low-cost flow calibration to be realized in an ordinary laboratory environment.

[0014] (2) This calibration system is a special system with simple structure, low cost and easy implementation. It can simulate the core measurement environment in drainage pipelines. When using this system, it can accurately and efficiently perform dynamic testing of the flow meter under test at multiple flow velocity points, comprehensively evaluate its performance, and solve the problem of the disconnect between laboratory calibration and field application conditions. It realizes a calibration method that is closer to the actual application scenario, realizes the synchronization, automatic acquisition and comparison of standard velocity value and flow meter measurement value during the test, and reduces human error.

[0015] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0016] The above and other objects, features and advantages of the present invention will become more apparent from the accompanying drawings, in which like reference numerals generally represent like parts.

[0017] Figure 1 A schematic diagram of a drainage pipe flow meter testing and calibration system according to an embodiment of the present invention is shown.

[0018] Figure 2 A schematic diagram of a drainage pipe flow meter testing and calibration system according to an embodiment of the present invention is shown when the hydraulic cylinder is in the fully extended state.

[0019] Figure 3 A schematic diagram of a drainage pipe flow meter testing and calibration system according to an embodiment of the present invention is shown when the hydraulic cylinder is in a fully retracted state.

[0020] Figure 4 A schematic diagram of the structure between the L-shaped bracket and the railcar chassis according to an embodiment of the present invention is shown.

[0021] Explanation of reference numerals in the attached figures: 1. L-shaped bracket; 2. Fork plate; 3. Flow meter to be measured; 4. Data acquisition controller; 5. Track; 6. Hydraulic cylinder; 7. Electric turntable; 8. Track car chassis; 9. Simulated water tank; 10. Left frame; 11. Right frame; 12. Hydraulic cylinder support; 13. Electric turntable axis; 14. Hinge shaft. Detailed Implementation

[0022] Preferred embodiments of the present invention will now be described in more detail. While preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0023] like Figure 1 As shown, this utility model provides a test and calibration system for a drainage pipeline flow meter, comprising: Simulated water tank 9, with track 5 set along the water tank; The railcar is slidably mounted on the rail 5. The railcar includes a railcar chassis 8 and an L-shaped support 1. One end of the L-shaped support 1 is hinged to the railcar chassis 8 via an electric turntable 7. A hydraulic cylinder 6 is also provided between the L-shaped support 1 and the electric turntable 7. The telescopic end of the hydraulic cylinder 6 is hinged to one end of the L-shaped support 1. The servo motor is connected to the 8-drive system of the railcar chassis. The fork plate 2 is set at the other end of the L-shaped bracket 1. When the flow meter is calibrated, the flow meter 3 to be tested on the fork plate 2 is submerged below the liquid surface of the simulated water tank 9. The data acquisition controller 4 acquires the moving speed of the track vehicle and the measurement data of the flow meter 3 under test, and performs calibration and adjustment on the flow meter 3 under test based on the data.

[0024] Specifically, the calibration system includes a simulated water tank 9 and a track vehicle. The track vehicle, through the interaction of the L-shaped support 1 and the electric turntable 7, can immerse the flow meter 3 under test in the simulated water tank 9. When the track vehicle moves at a constant speed along the track 5, the flow meter 3 under test will move together with the L-shaped support 1, moving in the simulated water tank 9 where the water flow is still. This creates a relative state of still water flow and moving flow meter, and the flow meter can still obtain the flow value. The acquisition controller 4 monitors the moving speed of the track vehicle and the flow value of the flow meter 3 under test, compares the two data, and adjusts the flow meter 3 under test according to the moving speed of the track vehicle, thereby improving the accuracy and reliability of the flow meter.

[0025] In one embodiment, the simulated water tank 9 in the verification system can also be a test water tank, which is a tank used to hold water to simulate the liquid environment of the drainage pipe; the track 5 is fixedly installed above or on the side wall of the simulated water tank 9, the laying direction of the track 5 is consistent with the length direction of the water tank, and the straightness of the track 5 also needs to be precisely adjusted; the track car can reciprocate on the track 5, and a clamp can be set on the track car to install the flow meter 3 to be tested. The clamp only needs to be able to immerse the sensor part of the flow meter below the liquid surface of the simulated water tank 9.

[0026] In addition, the track vehicle chassis 8 is also equipped with a drive and speed measurement module (used to drive the track vehicle and accurately measure its instantaneous speed) and a data acquisition and processing control module (core control and calculation). The drive and speed measurement module may include: a drive motor (providing power), a transmission mechanism (converting the rotational motion of the motor into the linear motion of the track vehicle), and a speed sensor (used to measure the moving speed of the track vehicle in real time and with high precision, which is the standard reference speed v1, and can be a rotary encoder linked to the motor or wheels, a non-contact laser velocimeter, or a combination of both); the data acquisition and processing control module includes: a data acquisition interface (used to receive the speed signal from the speed sensor, and to receive the measured value output in real time by the flow meter under test 3 via wired or wireless means, usually the flow velocity value v2), a processing core (used to synchronously store the standard reference speed v1 and the flow velocity value v2, and execute the verification algorithm), and a human-machine interface (used to set test parameters, start / stop the test, and display real-time data, curves, and verification results).

[0027] The test and verification system protected by this utility model includes: 1. Replacement of track 5 and drive method: Track 5 can be a high-precision linear guide rail, or an I-beam or aluminum alloy profile. The drive method can be a servo motor + rack and pinion, a linear motor, or a frequency converter motor + wire rope winch (ensuring uniform speed). 2. Replacement of speed measurement method: The core is to accurately measure the linear speed of the track vehicle. In addition to using a rotary encoder linked to the motor, non-contact speed measurement solutions such as laser rangefinders or microwave radar speedometers can be used to directly measure the speed of the vehicle body. 3. Replacement of system composition: The data acquisition and processing controller can be an integrated embedded system, or a distributed architecture of "PLC (responsible for control and speed acquisition) + host computer (responsible for data reception and processing)". For small-scale, low-cost verification needs, even a microcontroller can be used as the core, combined with a mobile APP for data display and storage.

[0028] Preferably, the track 5 is set along the length of the simulated water tank 9. Driven by the servo motor, the track car drives the flow meter 3 to be measured to move in a uniform linear motion along the track 5 through the L-shaped bracket 1.

[0029] Specifically, track 5 is parallel to the length of the simulated water tank 9. This allows the track vehicle to move the flow meter 3 under test over a long distance while it is moving, thus providing a more stable flow value and facilitating the calibration of the flow meter 3.

[0030] like Figures 2 to 4As shown in the figure, one end of the L-shaped bracket 1 has a cross section in the shape of a Japanese character (double rectangle), the bottom cross beam of the L-shaped bracket 1 is connected to the electric turntable 7 through a hinge shaft 14, the middle cross beam of the L-shaped bracket 1 is connected to the telescopic end of the oil cylinder 6, and the fixed end of the oil cylinder 6 is connected to the electric turntable 7 through an oil cylinder support 12.

[0031] Preferably, the other end of the L-shaped bracket 1 is provided with a telescopic rod, the other end of the L-shaped bracket 1 is connected to one end of the telescopic rod through a telescopic cylinder, and the other end of the telescopic rod is connected to the fork plate 2.

[0032] Specifically, the oil cylinder 6 is arranged between the L-shaped bracket 1 and the electric turntable 7. When the flowmeter 3 to be tested needs to be immersed below the liquid level of the simulated water pool 9, the oil cylinder 6 can be switched to the retracted state, so that the L-shaped bracket 1 is closely attached to the rail car chassis 8, and the lower end arm of the L-shaped bracket 1 is vertically inserted into the simulated water pool 9; when the flowmeter 3 to be tested needs to be replaced and disassembled, the oil cylinder 6 can be switched to the fully extended state, so that the L-shaped bracket 1 and the electric turntable 7 form a maximum angle, and the lower end arm of the L-shaped bracket 1 is completely separated from the simulated water pool 9, then the lower end arm of the L-shaped bracket 1 is rotated to the bank of the simulated water pool 9 by the electric turntable 7, so that the flowmeter can be replaced. In addition, a telescopic cylinder is arranged on the lower end arm of the L-shaped bracket 1 to drive the telescopic rod to move, and the telescopic rod on the L-shaped bracket 1 can be retracted when replacing the flowmeter, which makes it more convenient to grab the flowmeter on the fork plate 2.

[0033] Preferably, the electric turntable 7 is further provided with a left frame 10 and a right frame 11, a rectangular frame groove is formed between the left frame 10 and the right frame 11, and the rectangular frame groove matches the shape of one end of the L-shaped bracket 1.

[0034] Preferably, the fixed part of the electric turntable 7 is connected to the rail car chassis 8.

[0035] Specifically, the left and right frames on the electric turntable 7 can limit the movement direction of the L-shaped bracket 1, and when the rail car drives the L-shaped bracket 1 to move in the simulated water pool 9, it ensures that the rail car and the L-shaped bracket 1 are relatively stationary and fixed, so as to avoid affecting the accuracy of the flow value measured by the flowmeter.

[0036] Preferably, the acquisition controller 4 is arranged on the electric turntable 7, and the acquisition controller 4 is located at the hinged end of the L-shaped bracket 1.

[0037] Specifically, in addition to monitoring the parameter values of the rail car and the flowmeter, the arrangement position of the acquisition controller 4 on the electric turntable 7 can ensure that the position of the entire verification system is stable when the L-shaped bracket 1 is turned over relative to the rail car chassis 8, and ensure that the rail car chassis 8 will not overturn due to center of gravity deviation.

[0038] Preferably, the fork plate 2 includes multiple branches, each of which can be connected to the flow meter 3 to be measured.

[0039] Specifically, the fork plate 2 can be set with four branches, so that four flow meters 3 under test can be fixed at the same time. The data acquisition controller 4 can record the data measured by five flow meters in real time at the same time, thus improving the efficiency of the calibration work.

[0040] Preferably, the bottom of the simulated water tank 9 is a semi-circular tubular groove.

[0041] Specifically, the bottom of the simulated drainage system is a semi-circular tubular groove, which can provide an environment similar in height to the actual drainage pipe for the measurement and calibration system.

[0042] This testing and calibration system can be used to calibrate and adjust the flow meter. The specific calibration steps are as follows: The track vehicle carrying the flow meter 3 to be measured moves at a constant linear speed along the track 5; The data acquisition controller 4 records the moving speed v1 of the track vehicle and the measured value v2 of the flow meter 3 in real time; The flow meter is calibrated by comparing v1 and v2.

[0043] The test calibration system needs to obtain v1 and v2 through the data acquisition controller 4 under different operating conditions, so as to calculate the absolute error of the flow meter under test 3; Absolute error e=v2 平均 -v1; v2 平均 The average value of v2 measured multiple times by the flow meter under test 3 when the railcar is running at speed v1.

[0044] Specifically, this test calibration step is implemented based on the aforementioned calibration system. Before conducting the calibration test, the flow meter 3 to be tested is securely installed on the fork plate 2, and its sensor portion is immersed in the water in the test pool. All data cables and power are connected, and the system is started. After the flow meter 3 to be tested is securely installed on the clamp of the railcar, the calibration test can be performed.

[0045] During the test, the data collected by the data acquisition controller 4 when the track car moves the flow meter under test 3 in the simulated water tank 9 is used as a reference. Simultaneously, the running speed v1 of the track car and the flow velocity v2 measured by the flow meter are recorded in real time. The water in the simulated drainage pipe is stationary. The flow meter under test 3 moves in a uniform linear motion relative to the water at a speed of v1, where v1 can be considered equivalent to the water velocity, and v2 is the water velocity measured by the flow meter under test 3. Since the flow rate of a drainage pipe is equal to the product of the flow velocity and the cross-sectional area of ​​the water in the pipe, under the same pipe diameter and liquid level conditions, the flow rate is directly proportional to the flow velocity. The flow rate can be verified by comparing the flow velocities. The absolute error, relative error, mean absolute error, and mean square error of the flow meter under test 3 can be calculated using v1 and v2 collected under different operating conditions. The absolute error e = average v2 - v1 (where average v2 is the average value of multiple measurements of v2 by the flow meter under test 3 when the track car is running at speed v1), and the relative error δ = e / v1. This method can be used to calibrate flow meters in drainage pipes, thereby improving the accuracy of flow meter measurement data.

[0046] In this test calibration process, the turbidity of the water in the pool, the time the flow meter was placed in the pool, and the running speed of the railcar were used as variables. The experiment was conducted using the controlled variable method to obtain the test data of the drainage pipe flow meter and the actual relative flow velocity at different relative flow velocities in water with different turbidity levels under different placement times. This allowed the accuracy and reliability of the drainage pipe flow meter to be determined.

[0047] In summary, the specific steps for this test and calibration system to calibrate a Doppler flowmeter are as follows: Part 1: System Setup 1. Construct a concrete test pool measuring 30m long, 8m wide, and 5m deep. 2. Lay two high-precision linear guide rails as track 5 along the top of one side wall of the pool. 3. The track vehicle is made of aluminum profiles and driven by a servo motor via a belt. Adjustable mounting clamps are suspended below the vehicle body. 4. The servo motor has a built-in 24-bit high-resolution rotary encoder for accurate speed measurement. 5. The data acquisition and processing controller consists of an industrial computer (ICC) and a data acquisition card, and is equipped with a touch screen.

[0048] Part Two: Verification Process

[0049] Step 1: Fix the three Doppler flowmeters to be calibrated onto the fixtures of the track vehicle (there are four flowmeter mounting positions; install three and leave one empty). Adjust their probe depths to 0.5 meters, 1 meter, and 1.5 meters underwater; for the first round of testing, adjust to 1 meter. Connect the data output lines of the Doppler flowmeters to the RS485 interface of the industrial control computer. Step 2: Set the test plan on the touchscreen: test at seven speed points sequentially: 0.1 m / s, 0.3 m / s, 0.5 m / s, 1.0 m / s, 2.0 m / s, 3.0 m / s, and 5.0 m / s. The effective uniform running distance at each speed point is 15 meters. Step 3: Start the test. After the track vehicle accelerates to 0.1 m / s, it enters the uniform speed section. The industrial control computer simultaneously records the speed v1 fed back by the encoder and the flow velocity value v2 measured by the Doppler flowmeter. Step 4: Complete the test at the seven speed points sequentially. Step 5: The system automatically calculates the average relative error at each speed point and plots the calibration curve. The report shows that Doppler flowmeter #1 has a significant positive deviation of approximately +5% at 0.3 m / s, and Doppler flowmeter #3 has a significant positive deviation of approximately +5% at 1 m / s, suggesting that on-site calibration may be necessary.

[0050] Final result: This embodiment completed the multi-point calibration of the Doppler flowmeter in half a day, accurately locating its measurement deviation, while sending it to a laboratory would take several weeks and incur high costs.

[0051] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A test and calibration system for a flow meter in a drainage pipeline, characterized in that, Comprising: a simulated water tank, with a rail arranged along the edge of the tank; a rail car, slidably arranged on said rail, said rail car comprising a rail car chassis and an L-shaped bracket, one end of said L-shaped bracket is hingedly connected to said rail car chassis via an electric rotary table, an oil cylinder is further arranged between said L-shaped bracket and said electric rotary table, the telescopic end of said oil cylinder is hingedly connected to one end of said L-shaped bracket; a servo motor, drivingly connected to said rail car chassis; a fork plate, arranged at the other end of said L-shaped bracket, when a flowmeter is calibrated and tested, the flowmeter to be tested on said fork plate is submerged below the liquid level of said simulated water tank; an acquisition controller, which acquires the moving speed of said rail car and the measurement data of the flowmeter to be tested, and calibrates and adjusts the flowmeter to be tested according to the two sets of data.

2. The drainage pipeline flow meter testing and calibration system according to claim 1, characterized in that, Said rail is arranged along the length direction of said simulated water tank, driven by said servo motor, said rail car drives the flowmeter to be tested to perform uniform linear motion along said rail via said L-shaped bracket.

3. The drainage pipeline flow meter testing and calibration system according to claim 1, characterized in that, The cross-section of one end of said L-shaped bracket is in a Japanese-character shape, the bottom cross beam of said L-shaped bracket is connected to the rotating part of said electric rotary table via a hinge shaft, the middle cross beam of said L-shaped bracket is connected to the telescopic end of said oil cylinder, and the fixed end of said oil cylinder is connected to the rotating part of said electric rotary table via an oil cylinder support.

4. The drainage pipeline flow meter testing and calibration system according to claim 1, characterized in that, The rotating part of said electric rotary table is further provided with a left frame and a right frame, a rectangular frame groove is formed between said left frame and said right frame, and said rectangular frame groove matches the shape of one end of said L-shaped bracket.

5. The drainage pipeline flow meter testing and calibration system according to claim 1, characterized in that, The other end of said L-shaped bracket is provided with a telescopic rod, the other end of said L-shaped bracket is connected to one end of said telescopic rod via a telescopic cylinder, and the other end of said telescopic rod is connected to said fork plate.

6. The drainage pipeline flow meter testing and calibration system according to claim 1, characterized in that, Said acquisition controller is arranged on the rotating part of said electric rotary table, and said acquisition controller is located at the hinged end of said L-shaped bracket.

7. The drainage pipeline flow meter testing and calibration system according to claim 1, characterized in that, Said fork plate comprises a plurality of branch parts, each of said branch parts can be connected to a flowmeter to be tested.

8. The drainage pipeline flow meter testing and calibration system according to claim 1, characterized in that, The bottom of said simulated water tank is a semicircular tubular groove.

9. The drainage pipeline flow meter testing and calibration system according to claim 1, characterized in that, The fixed part of said electric rotary table is connected to said rail car chassis.

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