A flow rate calibration system combining standard meter detection and variable open channel detection

Abstract

The present invention relates to a flow calibration system combining standard meter detection and variable open channel detection, comprising a first calibration mechanism for detecting a small-diameter pipeline flowmeter, a second calibration mechanism for detecting a large-diameter pipeline flowmeter, and a third calibration mechanism for detecting an open channel flowmeter, wherein the first calibration mechanism, the second calibration mechanism, and the third calibration mechanism are arranged in sequence according to the water flow conveying direction. The small-diameter pipeline flowmeter can be calibrated by the first calibration mechanism; the large-diameter pipeline flowmeter can be calibrated by combining the first calibration mechanism and the second calibration mechanism; the open channel flowmeter can be calibrated by the third calibration mechanism; the application range is wide, and the convenience of the calibration process is increased.

Description

Technical Field

[0001] The invention relates to the technical field of flow meter detection equipment, and in particular to a flow calibration system combining standard meter detection with variable open channel detection. Background Art

[0002] Ultrasonic open channel flowmeter and ultrasonic pipe flowmeter are two common measuring instruments. Both ultrasonic open channel flowmeter and ultrasonic pipe flowmeter need to be calibrated before use to ensure the accuracy of the test results.

[0003] At present, there are open channel flowmeter verification / calibration devices for quality supervision and management of open channel flowmeters, and there are pipeline flowmeter verification / calibration devices for quality supervision and management of pipeline flowmeters. However, when a manufacturer needs to conduct verification / calibration of open channel flowmeters and pipeline flowmeters at the same time, it may be necessary to conduct inspections in two different places or locations, which is extremely inconvenient.

[0004] Patent application number 201710469984.1, open channel and pipe sewage flow integrated standard device, including water flow control system, open channel detection section, pipe detection section, inverted U-shaped pipe and return channel. This application can simultaneously perform the verification / calibration of ultrasonic open channel flowmeters and ultrasonic pipe flowmeters, but can only perform the verification of pipe flowmeters with small pipe diameters. In addition, its open channel is a fixed open channel, that is, the width, slope, and drop of the channel cannot be adjusted. Therefore, compared with the actual channel, the simulation is poor, it cannot simulate the real hydrological environment, and the detection results are inaccurate. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a flow rate calibration system combining standard meter detection with variable open channel detection.

[0006] The present invention is achieved through the following technical scheme, which provides a flow calibration system combining standard meter detection and variable open channel detection, including a first calibration mechanism for detecting a small-diameter pipeline flow meter, a second calibration mechanism for detecting a large-diameter pipeline flow meter, and a third calibration mechanism for detecting an open channel flow meter. The first calibration mechanism, the second calibration mechanism, and the third calibration mechanism are arranged in order according to the water flow conveying direction.

[0007] Preferably, the first verification mechanism includes a water storage tank supplied with water by a water pump, the water storage tank is connected to the head end water collection box through multiple small diameter water pipes, and a water outlet is provided on the head end water collection box; a standard small diameter pipeline flow meter is connected to each small diameter water pipe, and a small diameter pipeline flow meter to be inspected is connected to each small diameter water pipe. The standard small diameter pipeline flow meter and the small diameter pipeline flow meter to be inspected connected to the same small diameter water pipe have corresponding models. A switch valve and a pipeline drain valve are connected to each small diameter water pipe, and the switch valve is adjacent to the head end water collection box. The corresponding small diameter water pipe can be switched on and off by the switch valve, so that multiple small diameter water pipes can be selected for use. The pipeline drain valve can drain the water in the pipeline after the detection. The small-diameter pipeline flow meter to be inspected is connected to the small-diameter water pipeline through a flange and fixed with bolts. During inspection, the small-diameter pipeline flow meter to be inspected is installed on the small-diameter water pipeline. After the inspection is completed, the small-diameter pipeline flow meter to be inspected is removed.

[0008] Preferably, there are four small-diameter water pipes with a diameter of 500 mm, two small-diameter water pipes with a diameter of 400 mm, and one small-diameter water pipe with a diameter of 300 mm.

[0009] Preferably, the second calibration mechanism includes an end water collection box, which is provided with a water inlet, and a plurality of large-diameter water pipes with different diameters are provided between the end water collection box and the head water collection box, and each large-diameter water pipe is connected to a large-diameter pipe flow meter to be inspected with a corresponding diameter; the plurality of large-diameter water pipes are assembled together through two mounting plates and arranged circumferentially on the mounting plates; the mounting plates rotate with the plurality of large-diameter water pipes driven by a power mechanism.

[0010] Preferably, reducers are connected at both ends of each large-diameter water delivery pipeline, wherein the reducer at one end is butted against the water outlet on the head end water collection box, and the reducer at the other end is butted against the water inlet on the end water collection box. Flanges are provided on the reducer, the water outlet, and the water inlet, and the flange of the reducer is butted against the flange of the water outlet and connected by bolts, and the flange of the reducer is butted against the flange of the water inlet and connected by bolts.

[0011] Preferably, there is one large-diameter water pipeline with a diameter of 1200 mm, one large-diameter water pipeline with a diameter of 1400 mm, one large-diameter water pipeline with a diameter of 1600 mm, one large-diameter water pipeline with a diameter of 1800 mm, and one large-diameter water pipeline with a diameter of 2000 mm.

[0012] Preferably, the power mechanism includes two sets of electric roller frames, and the two mounting plates are respectively placed on the two sets of electric roller frames. The mounting plates are driven to rotate by the two sets of electric roller frames, thereby realizing the rotation of multiple large-diameter water pipes.

[0013] Preferably, a water distribution pipe is connected to the terminal water collection box, and the water distribution pipe is connected to a fixed open channel.

[0014] Preferably, the third calibration mechanism includes an energy-dissipating water tank, a drainage trough and a variable channel body. The variable channel body is located between the energy-dissipating water tank and the drainage trough. The energy-dissipating water tank is connected to the terminal water collecting tank through multiple drainage pipes. The energy-dissipating water tank is provided with a drainage outlet for discharging water to the variable channel body; the drainage trough is provided with a water inlet for water in the variable channel body to enter, and the drainage trough is provided with an electric flap-type gate for controlling drainage.

[0015] Preferably, a number of downpipes corresponding to the number of drainage pipes and arranged vertically are provided inside the energy dissipation water tank, the upper end of each downpipe is fixed to the top surface of the energy dissipation water tank, a gap is left between the lower end of each downpipe and the bottom surface of the energy dissipation water tank, and each drainage pipe is connected to a downpipe. The water in the terminal water collection tank is discharged into the energy dissipation water tank through the downpipe, and since the water is discharged downward, the impact force of the water discharge can be effectively reduced.

[0016] Preferably, the variable channel body includes two channel bottoms and two channel walls, the two channel walls are respectively located on the two channel bottoms, and a storage groove is provided between the two channel bottoms along the extension direction of the variable channel body. The spacing between the two channel walls is adjustable, the angle between each channel wall and its corresponding channel bottom is adjustable, and the height difference at both ends of each channel bottom is adjustable.

[0017] Preferably, each channel bottom includes a bottom support frame with a surface covering panel, each channel wall includes a side support frame with a surface covering panel, and each side support frame is connected to the bottom support frame through an adjustment device. The adjustment device includes multiple groups of adjustment mechanisms, which are arranged in sequence along the extension direction of the variable channel body; each group of adjustment mechanisms includes a sliding seat slidably connected to the bottom support frame, and a sliding groove for sliding the sliding seat is provided on the bottom support frame, the lower part of the side support frame is hinged to one end of the sliding seat, the push rod of the angle adjustment cylinder is hinged to the upper part of the side support frame, and the cylinder seat of the angle adjustment cylinder is hinged to the other end of the sliding seat. The cylinder seat of the channel width adjustment cylinder is fixedly connected to the bottom support frame, and the push rod of the channel width adjustment cylinder is fixedly connected to the sliding seat. The distance between the two channel walls can be adjusted by controlling the channel width adjustment cylinder, and the angle between the channel wall and its corresponding channel bottom can be adjusted by controlling the angle adjustment cylinder.

[0018] Preferably, the two sides of the waterproof cloth are fixed on the two channel walls respectively, the middle part of the waterproof cloth covers the channel bottom and covers the storage slot, and a cloth collecting mechanism is installed in the storage slot. The cloth collecting mechanism includes a bracket fixed to the bottom surface of the storage slot and arranged along the extension direction of the variable channel body, a clamping rod is arranged on both sides of the bracket, and a gap is left between each clamping rod and the bottom support frame for the waterproof cloth to fall into, and the two clamping rods are connected to the bracket through a supporting device. The supporting device includes a plurality of bidirectional oil cylinders and a plurality of cross arms, the bidirectional oil cylinders and the cross arms are arranged at intervals, and the two push rods of each bidirectional oil cylinder are fixed to the two clamping rods respectively. Each cross arm includes a first rotating arm and a second rotating arm, and the first rotating arm and the second rotating arm are hinged; one end of the first rotating arm is hinged to one of the clamping rods, and the other end of the first rotating arm is slidably connected to the other clamping rod; one end of the second rotating arm is hinged to one of the clamping rods, and the other end of the second rotating arm is slidably connected to the other clamping rod. The sliding connection method here is: a sliding groove is provided on the pressing rod, a sliding block is provided in the sliding groove, and the first rotating arm and the second rotating arm are both connected to the sliding block.

[0019] When the distance between the two channel walls becomes smaller, the two channel walls move closer to the storage slot, and the two channel walls push the waterproof cloth so that the excess part of the waterproof cloth falls into the gap on both sides. When the positions of the two channel walls are adjusted, the two-way cylinder is operated to make the two clamping rods squeeze the waterproof cloth that falls into the gap on both sides, that is, to seal the waterproof cloth in the gap to prevent water from entering the waterproof cloth in the gap.

[0020] Preferably, a cover plate is buckled at the storage slot, the cloth collecting mechanism is located below the cover plate, and the cover plate is connected to the bracket. A gap is left between the cover plate and the bottom support frame for the waterproof cloth to fall into.

[0021] Preferably, lifting cylinders are installed at both ends of each bottom support frame. By adjusting the lifting cylinders, the height difference between the two ends of the channel bottom can be adjusted. The adjustment of the height difference between the two ends of the channel bottom can simulate the actual height difference of the channel on the one hand, and realize the adjustment of the water flow speed on the other hand.

[0022] The beneficial effects of the present invention are:

[0023] 1. The first calibration mechanism can be used to calibrate small-diameter pipeline flow meters; the first calibration mechanism and the second calibration mechanism can be combined to calibrate large-diameter pipeline flow meters; the third calibration mechanism can be used to calibrate open channel flow meters; it has a wide range of applications and increases the convenience of the calibration process.

[0024] 2. The variable channel body of the third inspection mechanism can adjust the width, slope, drop, etc. of the channel. Compared with the actual channel, it has high simulation and simulates the real hydrological environment, and the test results are highly accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is an isometric view of the present invention;

[0026] Figure 2 It is a schematic diagram of the top view structure of the present invention;

[0027] Figure 3 yes Figure 1 A schematic diagram of the partially enlarged structure at center A;

[0028] Figure 4 yes Figure 1 A schematic diagram of the partially enlarged structure at B in the middle;

[0029] Figure 5 yes Figure 1 A schematic diagram of the partially enlarged structure at C in the middle;

[0030] Figure 6 yes Figure 1 The schematic diagram of the local enlarged structure at D in the middle;

[0031] Figure 7 It is an isometric view of the variable channel body of the present invention;

[0032] Figure 8 yes Figure 7 The schematic diagram of the local enlarged structure at E in the middle;

[0033] Fig. 9 This is a schematic diagram of the end surface structure of the variable channel body of the present invention;

[0034] Fig.10 This is a physical diagram of the first verification mechanism of the present invention;

[0035] Fig.11 This is a physical diagram of the second verification mechanism of the present invention;

[0036] Fig.12 This is a physical picture of one of the viewing angles of the third verification mechanism of the present invention;

[0037] Fig.13 This is a physical picture of the third verification mechanism of the present invention from another perspective;

[0038] As shown in the figure:

[0039] 1. Water storage tank, 2. Water pump, 3. Small-diameter water pipeline, 4. Standard small-diameter pipeline flowmeter, 5. Switch valve, 6. Head water tank, 7. Water outlet, 8. Reducer, 9. Mounting plate, 10. Large-diameter water pipeline, 11. Electric roller frame, 12. End water tank, 13. Drainage pipeline, 14. Valve switch, 15. Energy dissipation tank, 16. Water distribution pipe, 17. Fixed open channel, 18. Bottom support frame, 19. Side support frame, 20. Sliding seat, 21. Angle adjustment cylinder, 22. Channel width adjustment cylinder, 23. Water inlet, 24. Drainage trough, 25. Electric flap gate, 26. Water inlet, 27. Lifting cylinder, 28. Storage trough, 29. Bracket, 30. Clamping rod, 31. Cross arm, 32. Two-way cylinder, 33. Waterproof cloth. DETAILED DESCRIPTION

[0040] In order to clearly illustrate the technical features of this solution, this solution is described below through a specific implementation method.

[0041] like Figure 1-13 As shown, the present invention includes a first calibration mechanism for detecting a small-diameter pipeline flowmeter, a second calibration mechanism for detecting a large-diameter pipeline flowmeter, and a third calibration mechanism for detecting an open channel flowmeter. The first calibration mechanism, the second calibration mechanism, and the third calibration mechanism are arranged in order according to the water flow conveying direction.

[0042] The first inspection mechanism includes a water storage tank 1 supplied with water by a water pump 2. The water storage tank 1 is connected to a head-end water collection box 6 through a plurality of small-diameter water pipes 3. A water outlet 7 is provided on the head-end water collection box 6. A standard small-diameter pipeline flow meter 4 is connected to each small-diameter water pipe 3. A small-diameter pipeline flow meter to be inspected is connected to each small-diameter water pipe 3. The standard small-diameter pipeline flow meter 4 and the small-diameter pipeline flow meter to be inspected connected to the same small-diameter water pipe 3 have corresponding models. A switch valve 5 and a pipeline drain valve are connected to each small-diameter water pipe 3. The switch valve 5 is adjacent to the head-end water collection box 6. The corresponding small-diameter water pipe 3 can be switched on and off by the switch valve 5, so that multiple small-diameter water pipes 3 can be selected for use. The pipeline drain valve can drain the water in the pipeline after the inspection. The small-diameter pipeline flowmeter to be inspected is connected to the small-diameter water pipeline 3 through a flange and fixed by bolts. During inspection, the small-diameter pipeline flowmeter to be inspected is installed on the small-diameter water pipeline 3. After the inspection is completed, the small-diameter pipeline flowmeter to be inspected is removed.

[0043] In this embodiment, there are four small-diameter water pipes 3 with a diameter of 500 mm, two small-diameter water pipes 3 with a diameter of 400 mm, and one small-diameter water pipe 3 with a diameter of 300 mm.

[0044] The second inspection mechanism includes a terminal water collection box 12, on which a water inlet 26 is provided, and a plurality of large-diameter water pipes 10 with different diameters are provided between the terminal water collection box 12 and the head water collection box 6, and a large-diameter pipe flow meter to be inspected corresponding to the diameter is connected to each large-diameter water pipe 10. The plurality of large-diameter water pipes 10 are assembled together through two mounting plates 9 and arranged circumferentially on the mounting plates 9. The mounting plates 9 rotate with the plurality of large-diameter water pipes 10 driven by a power mechanism. A reducer 8 is connected to both ends of each large-diameter water pipe 10, wherein the reducer 8 at one end is connected to the water outlet 7 on the head water collection box 6, and the reducer 8 at the other end is connected to the water inlet 26 on the terminal water collection box 12. Flanges are provided on the reducer 8, the water outlet 7 and the water inlet 26. The flange of the reducer 8 and the flange of the water outlet 7 are connected by bolts after being butted against each other. The flange of the reducer 8 and the flange of the water inlet 26 are connected by bolts after being butt against each other.

[0045] A water distribution pipe 16 is connected to the terminal water collection box 12, and the water distribution pipe 16 is connected to a fixed open channel 17, and the width and slope of the fixed open channel 17 are both fixed values.

[0046] In this embodiment, there is one large-diameter water pipe 10 with a diameter of 1200 mm, one large-diameter water pipe 10 with a diameter of 1400 mm, one large-diameter water pipe 10 with a diameter of 1600 mm, one large-diameter water pipe 10 with a diameter of 1800 mm, and one large-diameter water pipe 10 with a diameter of 2000 mm.

[0047] The power mechanism includes two sets of electric roller frames 11, which are existing structures. Two mounting plates 9 are respectively placed on the two sets of electric roller frames 11. The mounting plates 9 are driven to rotate by the two sets of electric roller frames 11, thereby realizing the rotation of multiple large-diameter water pipes 10.

[0048] When calibrating a small-diameter pipeline flow meter, the flow data obtained by the standard small-diameter pipeline flow meter on the same small-diameter water pipeline is compared with the flow data obtained by the small-diameter pipeline flow meter to be inspected, so as to know the accuracy of the small-diameter pipeline flow meter to be inspected.

[0049] When calibrating the large-diameter pipeline flowmeter, taking the 1600 mm large-diameter pipeline flowmeter as an example, first open a small-diameter water pipeline 3 with a diameter of 500 mm, two small-diameter water pipelines 3 with a diameter of 400 mm, and a small-diameter water pipeline 3 with a diameter of 300 mm, and close the remaining small-diameter water pipelines 3. Then install the 1600 mm large-diameter pipeline flowmeter on the large-diameter water pipeline 10 with a diameter of 1600 mm, and then rotate the mounting plate 9 driven by the power mechanism until the large-diameter water pipeline 10 with a diameter of 1600 mm is connected to the water outlet 7 and the water inlet 26. The water in the head end water collection box 6 enters the 1600 mm large-diameter water pipeline 10, and the 1600 mm large-diameter pipeline flowmeter obtains flow data. The flow data obtained by a 500mm small-diameter pipe flowmeter, plus the flow data obtained by two 400mm small-diameter pipe flowmeters, plus the flow data obtained by a 300mm small-diameter pipe flowmeter, can be compared with the flow data obtained by a 1600mm large-diameter pipe flowmeter to verify the measurement accuracy of the 1600mm large-diameter pipe flowmeter.

[0050] The third inspection mechanism includes a stilling water tank 15, a drainage trough 24 and a variable channel body. The variable channel body is located between the stilling water tank 15 and the drainage trough 24. The stilling water tank 15 is connected to the terminal water collection tank 12 through a plurality of drainage pipes 13, and a valve switch 14 is connected to each drainage pipe 13. Downpipes (not marked in the figure) corresponding to the number of drainage pipes 13 and arranged vertically are provided inside the stilling water tank 15. The upper end of each downpipe is fixed to the top surface of the stilling water tank 15, and a gap is left between the lower end of each downpipe and the bottom surface of the stilling water tank 15. Each drainage pipe 13 is connected to a downpipe. A drainage port for discharging water to the variable channel body is provided on the stilling water tank 15. The water in the terminal water collection tank 12 is discharged into the stilling water tank 15 through the downpipe. Since the water is discharged downward, the impact force of the water discharge can be effectively reduced. A water inlet 23 is provided on the drainage trough 24 for water in the variable channel body to enter, and an electric flap gate 25 for controlling drainage is provided on the drainage trough 24, and the electric flap gate 25 is an existing structure.

[0051] like Figure 7 , 8 9 The variable channel body includes two channel bottoms and two channel walls. The two channel walls are respectively located on the two channel bottoms. A receiving groove 28 is provided between the two channel bottoms along the extension direction of the variable channel body. The spacing between the two channel walls is adjustable, the angle between each channel wall and its corresponding channel bottom is adjustable, and the height difference between the head and tail ends of each channel bottom is adjustable.

[0052] Each channel bottom includes a bottom support frame 18 with a surface covered with panels, and each channel wall includes a side support frame 19 with a surface covered with panels, and each side support frame 19 is connected to the bottom support frame 18 through an adjustment device. The adjustment device includes multiple groups of adjustment mechanisms, which are arranged in sequence along the extension direction of the variable channel body; each group of adjustment mechanisms includes a sliding seat 20 slidably connected to the bottom support frame 18, and a sliding groove for sliding the sliding seat 20 is provided on the bottom support frame 18, the lower part of the side support frame 19 is hinged to one end of the sliding seat 20, the push rod of the angle adjustment cylinder 21 is hinged to the upper part of the side support frame 19, and the cylinder seat of the angle adjustment cylinder 21 is hinged to the other end of the sliding seat 20. The cylinder seat of the channel width adjustment cylinder 22 is fixedly connected to the bottom support frame 18, and the push rod of the channel width adjustment cylinder 22 is fixedly connected to the sliding seat 20. The distance between the two channel walls can be adjusted by controlling the channel width adjustment cylinder 22 , and the angle between the channel wall and its corresponding channel bottom can be adjusted by controlling the angle adjustment cylinder 21 .

[0053] The two sides of the waterproof cloth 33 are fixed on the two channel walls respectively, the middle part of the waterproof cloth 33 covers the channel bottom and covers the storage slot 28, and a cloth collecting mechanism is installed in the storage slot 28. The cloth collecting mechanism includes a bracket 29 fixed to the bottom surface of the storage slot 28 and arranged along the extension direction of the variable channel body, and a clamping rod 30 is arranged on both sides of the bracket 29. There is a gap between each clamping rod 30 and the bottom support frame 18 for the waterproof cloth 33 to fall into, and the two clamping rods 30 are connected to the bracket 29 through a supporting device. The supporting device includes a plurality of bidirectional oil cylinders 32 and a plurality of cross arms 31. The bidirectional oil cylinders 32 and the cross arms 31 are arranged at intervals, and the two push rods of each bidirectional oil cylinder 32 are fixedly connected to the two clamping rods 30 respectively. Each cross arm 31 includes a first rotating arm and a second rotating arm, the first rotating arm and the second rotating arm are hinged; one end of the first rotating arm is hinged to one of the clamping rods 30, and the other end of the first rotating arm is slidably connected to the other clamping rod 30; one end of the second rotating arm is hinged to one of the clamping rods 30, and the other end of the second rotating arm is slidably connected to the other clamping rod 30. The sliding connection method here is: a slide groove is provided on the clamping rod 30, a slider is provided in the slide groove, and the first rotating arm and the second rotating arm are both connected to the slider. This sliding connection form is a commonly used sliding form in the cross lifting structure.

[0054] When the distance between the two channel walls becomes smaller, the two channel walls approach the storage groove 28, and the two channel walls push the waterproof cloth 33, so that the excess part of the waterproof cloth 33 falls into the gaps on both sides. When the positions of the two channel walls are adjusted, the two-way oil cylinder 32 is operated to make the two pressing rods 30 squeeze the waterproof cloth 33 falling into the gaps on both sides, that is, to seal the waterproof cloth 33 in the gaps to prevent water from entering the waterproof cloth 33 in the gaps. In order to prevent the waterproof cloth 33 above the storage groove 28 from sinking due to the gravity of the water, a cover plate is buckled at the storage groove 28, and the cloth collection mechanism is located below the cover plate, and the cover plate is connected to the bracket 29. There is a gap between the cover plate and the bottom support frame 18 for the waterproof cloth 33 to fall into.

[0055] Lifting cylinders 27 are installed at both ends of each bottom support frame 18. By adjusting the lifting cylinders 27, the height difference between the two ends of the channel bottom can be adjusted. The adjustment of the height difference between the two ends of the channel bottom can simulate the actual height difference of the channel on the one hand, and adjust the water flow speed on the other hand.

[0056] Of course, the above description is not limited to the above examples. Technical features not described in the present invention can be achieved by or by using existing technologies, which will not be described here. The above embodiments and drawings are only used to illustrate the technical scheme of the present invention and are not limitations of the present invention. The present invention is described in detail with reference to the preferred implementation methods. Ordinary technicians in this field should understand that changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention do not depart from the purpose of the present invention, and should also fall within the scope of protection of the claims of the present invention.

Claims

1. A flow rate calibration system combining standard meter detection and variable open channel detection, characterized in that: It includes a first verification mechanism for detecting a small-diameter pipeline flowmeter, a second verification mechanism for detecting a large-diameter pipeline flowmeter, and a third verification mechanism for detecting an open channel flowmeter, and the first verification mechanism, the second verification mechanism, and the third verification mechanism are arranged in order according to the water flow conveying direction; The first inspection mechanism comprises a water storage tank supplied with water by a water pump, the water storage tank is connected to a head end water collection tank through a plurality of small diameter water delivery pipes, and a water outlet is provided on the head end water collection tank; a standard small diameter pipeline flow meter is connected to each small diameter water delivery pipe, and a small diameter pipeline flow meter to be inspected is connected to each small diameter water delivery pipe; The second inspection mechanism comprises a terminal water collection box, which is provided with a water inlet, and a plurality of large-diameter water pipes with different diameters are provided between the terminal water collection box and the head-end water collection box, and each large-diameter water pipe is connected to a large-diameter pipe flow meter to be inspected with a corresponding diameter; the plurality of large-diameter water pipes are assembled together through two mounting plates and arranged circumferentially on the mounting plates; the mounting plates rotate with the plurality of large-diameter water pipes under the drive of the power mechanism; The third inspection mechanism includes a stilling water tank, a drainage trough and a variable channel body, wherein the variable channel body is located between the stilling water tank and the drainage trough, the stilling water tank is connected to the terminal water collection tank through a plurality of drainage pipes, a drainage port for discharging water to the variable channel body is provided on the stilling water tank, a water inlet for water in the variable channel body to enter is provided on the drainage trough, and an electric flap gate for controlling drainage is provided on the drainage trough; The variable channel body comprises two channel bottoms and two channel walls, the two channel walls are respectively located on the two channel bottoms, a receiving groove is provided between the two channel bottoms along the extension direction of the variable channel body, the spacing between the two channel walls is adjustable, the angle between each channel wall and its corresponding channel bottom is adjustable, and the height difference between the head and tail ends of each channel bottom is adjustable; Each channel bottom includes a bottom support frame with a surface covering panel, each channel wall includes a side support frame with a surface covering panel, and each side support frame is connected to the bottom support frame through an adjustment device; the adjustment device includes multiple groups of adjustment mechanisms, and the multiple groups of adjustment mechanisms are arranged in sequence along the extension direction of the variable channel body; each group of adjustment mechanisms includes a sliding seat slidably connected to the bottom support frame, and a sliding groove for sliding the sliding seat is provided on the bottom support frame, the lower part of the side support frame is hinged to one end of the sliding seat, the push rod of the angle adjustment cylinder is hinged to the upper part of the side support frame, and the cylinder seat of the angle adjustment cylinder is hinged to the other end of the sliding seat; the cylinder seat of the channel width adjustment cylinder is fixedly connected to the bottom support frame, and the push rod of the channel width adjustment cylinder is fixedly connected to the sliding seat; The two sides of the waterproof cloth are respectively fixed on the two channel walls, the middle part of the waterproof cloth covers the channel bottom and covers the storage groove, and a cloth collecting mechanism is installed in the storage groove; the cloth collecting mechanism includes a bracket fixed to the bottom surface of the storage groove and arranged along the extension direction of the variable channel body, and a clamping rod is respectively arranged on both sides of the bracket, and a gap is reserved between each clamping rod and the bottom support frame for the waterproof cloth to fall into, and the two clamping rods are connected to the bracket through a supporting device; the supporting device includes a plurality of bidirectional oil cylinders and a plurality of cross arms, the bidirectional oil cylinders and the cross arms are arranged at intervals, and the two push rods of each bidirectional oil cylinder are respectively fixed to the two clamping rods.

2. A flow rate calibration system combining standard meter detection and variable open channel detection according to claim 1, characterized in that: Reducers are connected at both ends of each large-diameter water delivery pipeline, wherein the reducer at one end is connected to the water outlet on the head end water collection tank, and the reducer at the other end is connected to the water inlet on the end water collection tank.

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