Coupling type water meter automatic calibrating device

Abstract

The utility model discloses a coupling type automatic calibrating device for a water meter. The coupling type automatic calibrating device comprises a piston type main standard device and an electronic scale (with a measuring device), a water outlet of the piston type main standard device is provided with a piston water outlet valve and is connected with a water inlet of the verification station pipeline section, the verification station pipeline section is used for installing a plurality of water meters to be verified in series, and an acquisition terminal is arranged above each water meter to be verified; a water outlet of the verification station pipeline section is connected with one end of a first flow switching valve, one end of a second flow switching valve and one end of a third flow switching valve. According to the coupling type water meter automatic calibrating device, the double metering standard devices are used for calibrating the water meter, the cylindrical piston is adopted as the main standard device at the minimum flow point and the boundary flow point, the high-precision electronic scale is adopted as the main standard device at the common flow point, the whole calibrating process of the calibrating device is short in time consumption, and multiple water meters of the same specification can be calibrated in series; the verification efficiency is improved; and the verification work is scientific, accurate and efficient.

Description

Technical Field

[0001] The utility model relates to the technical field of metrology, and particularly relates to a coupled water meter automatic verification device. Background Technique

[0002] The metrological accuracy of a water meter is a key indicator to measure its quality. It is necessary for legal metrological verification institutions to carry out verification work on water meter verification devices to ensure its metrological accuracy and safeguard the legitimate rights and interests of both water supply and users. Water meter verification includes 4 verification items, namely appearance, markings and seals, electronic device functions, tightness, and indication error; among them, the indication error verification has the largest workload and the longest time consumption. It is mainly carried out by the comparison method, comparing the cumulative flow indication of the water meter with the actual volume measured by the metrological standard device to determine the indication error. The indication error verification generally verifies three flow points: the minimum flow Q1, the demarcation flow Q2, and the common flow Q3. Only when the indication errors at all three flow points meet the maximum allowable error requirements specified in the Verification Regulation of Cold Drinking Water Meters (JJG 162—2019) is it considered qualified.

[0003] The methods for verifying the indication error include the volumetric method, the mass method, the piston method, etc. Currently, the water meter verification devices used by legal metrological verification institutions and water meter manufacturers mainly adopt the volumetric method and the mass method. When performing verifications at the minimum flow point and the demarcation flow point, the verification time is long and the verification efficiency is low. There are start-stop effects or commutator effects, resulting in large systematic errors during verification and affecting the accuracy of the verification results. During the traditional mass method verification, the verification device vibrates greatly, which has a greater impact on the metrological standard device. It may cause zero drift of the weighing scale, and it is difficult to ensure the accuracy, especially serious when verifying at the minimum flow point and the demarcation flow point; in addition, the traditional volumetric method and mass method verification devices consume a large amount of energy, occupy a large space, and are not easy to move. The piston-type verification device can arbitrarily set and automatically adjust the flow rate within the device flow range, with high water pressure and flow stability, small vibration, low energy consumption, and small occupied space, and the verification is efficient and accurate; however, due to the relatively small power of the piston drive motor, it is only suitable for verifying the indication error at small flow points. Content of the Utility Model

[0004] The purpose of the utility model is to overcome the above-mentioned deficiencies of the prior art and provide a coupled water meter automatic verification device to improve the work efficiency and accuracy of water meter verification.

[0005] To achieve the above purpose, the technical solution of the utility model is:

[0006] A coupled water meter automatic calibration device, including a piston-type master standard device. A piston water outlet valve is installed at the water outlet of the piston-type master standard device and is connected to the water inlet of the calibration station pipeline section. The calibration station pipeline section is used for serially installing a number of water meters to be calibrated, and a collection terminal is arranged above each water meter to be calibrated. The water outlet of the calibration station pipeline section is respectively connected to one end of a first flow switching valve, a second flow switching valve, and a third flow switching valve. The other end of the first flow switching valve is connected to one end of a first flow meter. The other end of the second flow switching valve is connected to one end of a second flow meter. The other end of the third flow switching valve is connected to one end of a third flow meter. The other ends of the first flow meter and the second flow meter are both connected to a water tank. The other end of the third flow meter is connected to a work gauge through a reversing valve. A water discharge valve is arranged at the water outlet of the work gauge and is connected to the water tank. The work gauge is placed on an electronic scale. The water outlet of the water tank is connected to one end of a piston return water valve, and the other end of the piston return water valve is connected to the water return port of the piston-type master standard device. The water outlet of the water tank is also connected to one end of a water pump inlet valve, the other end of the water pump inlet valve is connected to the water inlet of the water pump, and the water outlet of the water pump is connected to the pipeline where the piston water outlet valve is connected to the water inlet of the calibration station pipeline section.

[0007] Further, the coupled water meter automatic calibration device further includes a meter clamp, and the meter clamp is used to clamp a number of water meters to be calibrated in series.

[0008] Further, the coupled water meter automatic calibration device further includes a pressure stabilizing container. The water inlet of the pressure stabilizing container is connected to the water outlet of the water pump. The water outlet of the pressure stabilizing container is connected to one end of a pressure stabilizing container outlet valve, and the other end of the pressure stabilizing container outlet valve is connected to the pipeline where the piston water outlet valve is connected to the water inlet of the calibration station pipeline section.

[0009] Further, an inlet pressure sensor and an inlet temperature sensor are also installed in the pipeline where the piston water outlet valve is connected to the water inlet of the calibration station pipeline section.

[0010] Further, an outlet pressure sensor and an outlet temperature sensor are also arranged at the water outlet of the calibration station pipeline section.

[0011] Further, a filter screen is also installed in the water tank.

[0012] Further, the collection terminal is an industrial camera or a smart phone.

[0013] Further, the piston-type master standard device includes a piston cylinder and a piston installed in the piston cylinder. The piston is connected to a ball screw, and the ball screw is driven by a motor to move. A grating scale is also arranged on one side of the ball screw. The piston cylinder is provided with a water outlet and a water return port.

[0014] Furthermore, the first flowmeter, the second flowmeter, and the third flowmeter are all float flowmeters.

[0015] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0016] The automatic calibration device for the coupled water meter uses dual metrology standards to calibrate the water meter. A piston is used as the main standard at the minimum flow point and the demarcation flow point, and a high-precision electronic scale (with a working measuring device) is used as the main standard at the normal flow point. The overall calibration process of the calibration device takes a short time, and multiple water meters of the same specification can be calibrated in series simultaneously, improving the calibration efficiency and saving calibration time; the calibration work is scientific, accurate, and efficient. Description of the Drawings

[0017] Figure 1 It is a schematic diagram of the composition of the automatic calibration device for the coupled water meter provided by the embodiment of the present utility model;

[0018] In the figure: 1, piston type main standard; 2, piston water outlet valve; 3, water meter to be calibrated; 4, acquisition terminal; 5, first flow switching valve; 6, second flow switching valve; 7, third flow switching valve; 8, first flowmeter; 9, second flowmeter; 10, third flowmeter; 11, reversing valve; 12, working measuring device; 13, drain valve; 14, piston return valve; 15, water pump inlet valve; 16, water pump; 17, meter clamp; 18, pressure stabilizing container; 19, pressure stabilizing container outlet valve; 20, inlet pressure sensor; 21, inlet temperature sensor; 22, outlet pressure sensor; 23, outlet temperature sensor; 24, filter screen; 25, water tank; 26 electronic scale; 101, piston cylinder; 102, piston; 103, ball screw; 104, motor; 105, grating scale. Detailed Embodiment

[0019] Embodiment:

[0020] The technical solution of the present utility model will be further described below in conjunction with the drawings and embodiments.

[0021] Refer to Figure 1As shown in the figure, the coupled water meter automatic verification device provided in this embodiment mainly includes a piston-type main standard device 1. A piston water outlet valve 2 is installed at the water outlet of the piston-type main standard device 1 and is connected to the water inlet of the verification station pipe section. The verification station pipe section is used for serially installing a number of water meters under test 3. A collection terminal 4 is arranged above each water meter under test 3 to collect the display of the water meter through the collection terminal 4; the water outlet of the verification station pipe section is respectively connected to one ends of a first flow switching valve 5, a second flow switching valve 6 and a third flow switching valve 7. The other end of the first flow switching valve 5 is connected to one end of a first flowmeter 8. The other end of the second flow switching valve 6 is connected to one end of a second flowmeter 9. The other end of the third flow switching valve 7 is connected to one end of a third flowmeter 10. The three flowmeters are arranged in parallel. The flowmeters are used as instantaneous flow indicators to display the water flow in real time, providing a basis for judging whether the flow rate reaches the verification point flow rate. There are multiple flow online monitoring channels. According to the flow rate during verification, the flow switching valve of the corresponding channel is automatically opened, and the verification flow rate is monitored online by the corresponding flowmeter. The other ends of the first flowmeter 8 and the second flowmeter 9 are connected to a water tank 25. The other end of the third flowmeter 10 is connected to a work meter 12 through a reversing valve 11. A drain valve 13 is arranged at the water outlet of the work meter 12 and is connected to the water tank 25. The work meter 12 is placed on an electronic scale 26. The electronic scale 26 is the original standard device for water flow rate, to measure the water volume flowing into the work meter 12 through the electronic scale 26, that is, the actual water volume flowing through the water meter under test 3; the water outlet of the water tank 25 is connected to one end of a piston return water valve 14. The other end of the piston return water valve 14 is connected to the water return port of the piston-type main standard device 1; the water outlet of the water tank 25 is also connected to one end of a water pump inlet valve 15. The other end of the water pump inlet valve 15 is connected to the water inlet of a water pump 16. The water outlet of the water pump 16 is connected to the pipeline where the piston water outlet valve 2 is connected to the water inlet of the verification station pipe section.

[0022] In this way, the coupled water meter automatic verification device uses dual metering standard devices to verify the water meter. A cylindrical piston is used as the main standard device at the minimum flow point and the demarcation flow point, and a high-precision electronic scale is used as the main standard device at the common flow point. The overall verification process of the verification device takes a short time, can serially verify multiple water meters of the same specification at the same time, improves the verification efficiency, and saves the verification time; the verification work is scientific, accurate and efficient.

[0023] As a preference of the above-mentioned coupled water meter automatic verification device, the device further includes a meter clamp 17. The meter clamp 17 is used to clamp a number of serially installed water meters under test. Before verification, the meter clamp 17 is driven by a cylinder to move towards the water meter under test 3 until the water meter under test 3 is centered and clamped.

[0024] As another preference of the above-mentioned coupled water meter automatic verification device, the device further includes a pressure stabilizing container 18. The water inlet of the pressure stabilizing container 18 is connected to the water outlet of the water pump 16. The water outlet of the pressure stabilizing container 18 is connected to one end of a pressure stabilizing container outlet valve 19. The other end of the pressure stabilizing container outlet valve 19 is connected to a pipeline where the piston water outlet valve 2 is connected to the water inlet of the verification station pipeline section. In this way, by setting up the pressure stabilizing container 18, the water flow entering the measurement section is ensured to be stable and the water pressure is stable during the verification of the normal flow rate point.

[0025] In a specific embodiment, an inlet pressure sensor 20 and an inlet temperature sensor 21 are further installed in the pipeline where the piston water outlet valve 2 is connected to the water inlet of the verification station pipeline section. An outlet pressure sensor 22 and an outlet temperature sensor 23 are also arranged at the water outlet of the verification station pipeline section. The inlet pressure sensor 20 automatically measures the water inlet pressure of the water meter during verification, and the outlet pressure sensor 22 automatically measures the water outlet pressure of the water meter during verification; the inlet temperature sensor 21 automatically measures the water inlet temperature of the water meter during verification, and the outlet temperature sensor 23 automatically measures the water outlet temperature of the water meter during verification. A filter screen 24 is also installed in the water tank 25. The water tank 25 provides water for the verification of the water meter, and the filter screen 24 ensures that the supplied water is clean.

[0026] In a specific embodiment, the acquisition terminal 4 is an industrial camera or a smart phone, which automatically locates the mechanical water meter, tracks the number of rotations and angles (coordinates) of the last pointer or the plum wheel, and converts the real-time image recognition into a water volume reading; for the electronic water meter, it directly recognizes the liquid crystal numbers in real time and converts them into a water volume reading, which can completely replace manual reading. The first flowmeter 8, the second flowmeter 9 and the third flowmeter 10 are all float flowmeters.

[0027] In a specific embodiment, the piston type main standard device 1 includes a piston cylinder 101 and a piston 102 installed in the piston cylinder 101. The piston 102 is connected to a ball screw 103. The ball screw 103 is driven by a motor 104 to move. A grating scale 105 is also arranged on one side of the ball screw 103. The piston cylinder 101 is provided with a water outlet and a water return port.

[0028] The steps for the coupled water meter automatic verification device provided in this embodiment to verify the water meter are as follows:

[0029] 1) Install the water meter to be verified on the verification station pipeline section, and center and clamp the water meter through the meter clamp.

[0030] 2) Open the water pump inlet valve, the pressure stabilizing container outlet valve, and the third flow rate switching valve, and close the piston water outlet valve, the piston water return valve, the first flow rate switching valve, and the second flow rate switching valve.

[0031] 3) Pass water within the rated flow range of the water meter to expel the air in the meter under test and the pipeline of the verification device corresponding to the normal flow verification point.

[0032] 4) Open the first flow switching valve and the second flow switching valve, and close the water pump inlet valve, the outlet valve of the pressure stabilizing container, and the third flow switching valve.

[0033] 5) Open the piston outlet valve and close the piston return valve. Control the driving motor to rotate forward to drive the piston to move forward until it reaches the bottom of the cylinder block. Pass water within the rated flow range of the water meter to expel the air in the meter, the cylinder block, and the pipeline of the verification device.

[0034] 6) Close the piston outlet valve and open the piston return valve. Control the driving motor to rotate in reverse to drive the piston to move backward until it reaches the head of the cylinder block, and suck the filtered water in the water tank to fill the piston cylinder.

[0035] 7) Repeat steps 5) to 6) until the air in the meter, the cylinder block, and the pipeline of the verification device is completely expelled.

[0036] 8) Use the flow-time method to verify the indication error of the water meter at the demarcation flow point: Open the piston outlet valve and close the piston return valve. Close the first flow switching valve and open the second flow switching valve. Control the driving motor to rotate forward and accelerate to the rotation speed corresponding to the flow value (Q2 - 1.1Q2) at the demarcation flow point and then keep rotating at a constant speed, driving the piston to move forward at a constant speed. Drain the water in the cylinder block at the demarcation flow point, pass through each meter under test in turn, and then drain into the water tank; after the piston changes from accelerating movement to uniform movement, start recording the ranging signal of the piston grating scale, and simultaneously record the starting time of the verification device; after the starting time of the verification device, each acquisition terminal starts to collect the cumulative flow indication of the corresponding meter under test and simultaneously record the verification starting time of each meter under test; after the meter under test has flowed through the specified verification water consumption, stop collecting the cumulative flow indication of each meter under test respectively, and use the corresponding end time as the verification end time of the corresponding meter under test. The latest verification end time of all meters under test is used as the end time of the device, and at the same time, stop the piston movement and receive the grating scale ranging signal; calculate the flow indication flowing through each meter according to the signal of the acquisition terminal of each meter under test, convert the standard volume measured by the piston main standard from the starting time to the end time of the device to the verification starting time to the verification end time period of each meter under test as the actual volume flowing through each meter under test, compare the flow indication and the actual volume of each meter under test, and calculate the indication error of each water meter at the demarcation flow verification point.

[0037] 9) Use the flow-time method to verify the indicated error at the minimum flow point of the water meter: Close the second flow switching valve and open the first flow switching valve. Based on the flow value at the minimum flow point of the water meter under test and the distance the piston has traveled forward, determine whether the drive motor can continue to rotate forward to complete the verification of the indicated error at the minimum flow point; if it can continue to rotate forward, refer to step 8) to complete the verification at this flow point, and adjust the flow to the flow value at the minimum flow point (Q1 to 1.1Q1) and keep it stable; if it cannot continue to rotate forward, first execute step 6), then open the piston water outlet valve and close the piston water return valve, and finally refer to step 8) to complete the verification at this flow point.

[0038] 10) Use the commutation method to verify the indicated error at the normal flow point of the water meter: Open the water pump inlet valve, the outlet valve of the pressure stabilizing container, and the third flow switching valve, and close the piston water outlet valve, the piston water return valve, the first flow switching valve, and the second flow switching valve. Automatically adjust the flow in the verification channel to the flow value at the normal flow point (0.9Q3 to Q3) and keep it stable by adjusting the water pump frequency and the opening of the third flow switching valve, and make the measuring container and the commutator of the metrological standard device in a working waiting state. The indicating device of the water meter under test is in a moving state. Automatically read the reading of the water meter through the acquisition terminal, synchronously start the commutator, and direct the water flow to the measuring container; after the water meter has flowed through the specified time or the verification water consumption, then synchronously start the commutator to divert the water flow away and into the water tank when reading the water meter reading; calculate the volume indication value flowing through the water meter, read the reading of the metrological standard device and calculate the actual volume flowing through the water meter (the volume of water collected in the measuring container is the actual volume flowing through the water meter), and compare the above two volume values to calculate the indicated error of the water meter at the normal flow verification point. When the reading of the water meter under test is not completely synchronized with the commutation time of the commutator of the metrological standard device, the double-time method can also be used for verification, that is, convert the standard volume measured by the metrological standard device to the verification time period of each water meter under test as the actual volume of each water meter under test, and then compare the cumulative volume indication value of each water meter under test with its actual volume to calculate the indicated error of each water meter under test. At this time, the verification of all flow points is completed.

[0039] 11) According to the "Verification Regulation of Cold Drinking Water Meters" (JJG 162—2019), automatically complete the verification of the appearance, markings and seals, functions of the electronic device, and tightness items of the water meter in sequence.

[0040] 12) Drain the water in the water meter and the pipelines of the verification device, and drive the clamp meter to move away from the water meter through the clamp meter cylinder to complete the disassembly of the water meter.

[0041] 13) Repeat steps 1) to 12) in the next round of verification to continuously achieve automatic verification of the water meter.

[0042] In steps 8) to 10), the water meter indication error is calculated according to the following formula (1):

[0043]

[0044] In the formula:

[0045] E — Relative indication error of the water meter, %;

[0046] V i — Volume increased (or decreased) on the water meter indicating device, m 3 or L;

[0047] t a — Time corresponding to the measured actual volume V a in seconds;

[0048] V a — Actual volume flowing through the water meter, m 3 or L;

[0049] t i — Time corresponding to the measured water meter indication volume V i in seconds.

[0050] V i is obtained by using a collection terminal (industrial camera or smartphone) to take pictures or photos and perform visual recognition.

[0051] In steps 8) to 9), the actual volume V flowing through the water meter a is calculated according to formula (2):

[0052]

[0053] In the formula:

[0054] V a — Actual volume flowing through the water meter, m 3 or L;

[0055] D — Inner diameter of the piston cylinder, m or dm;

[0056] L — Distance moved by the piston from the start time to the end time of the verification device, m or dm.

[0057] V a is obtained by measuring the distance moved by the piston with a grating ruler and then calculating through formula (2).

[0058] In summary, to solve the problems of low verification efficiency and low accuracy of volumetric and mass verification devices at low flow points, and the piston verification device being only suitable for verification under low flow point conditions, the present utility model proposes a coupled mass and piston method automatic water meter verification device. The device uses a dual metering standard to verify water meters. At the minimum flow point and the demarcation flow point, a cylindrical piston is used as the main standard, and at the normal flow point, a high-precision electronic scale is used as the main standard. The accuracy level of the verification device reaches 0.2 or the expanded uncertainty (k = 2) is better than 1 / 5 of the absolute value of the maximum allowable error of the water meter to be verified. At the minimum flow point and the demarcation flow point, verification is carried out using the flow-time method in accordance with the "Verification Regulation of Cold Drinking Water Meters" (JJG 162—2019). During verification, the servo motor drives the piston body to move at a constant speed, pressing the water in the piston cylinder out at a constant pressure and flow rate and then discharging it after passing through the water meter to be verified. The indicated error of the water meter to be verified is obtained by comparing the average flow rates of each water meter to be verified and the standard during the verification period. At the normal flow point, verification is carried out using the commutation method, automatically collecting the signals of the electronic scale during the verification period, and calculating the actual volume flowing through the water meter to be verified (the volume of water injected into the measuring container by the commutator). The volume indication value flowing through the water meter is automatically collected through the acquisition terminal, and the indicated error of each water meter to be verified is calculated by comparing the two volume values. The overall verification process of the verification device takes a short time, and multiple water meters of the same specification can be verified in series simultaneously (the number n is generally between 2 and 10), improving the verification efficiency, saving verification time, making the verification work scientific, accurate, and efficient, and providing a reference for domestic legal metrology verification institutions and water meter manufacturers to improve verification quality and efficiency.

[0059] The above embodiments are only used to illustrate the technical concept and characteristics of the present utility model. The purpose is to enable ordinary technicians in the field to understand the content of the present utility model and implement it accordingly, and it should not be used to limit the protection scope of the present utility model. Any equivalent changes or modifications made based on the essence of the content of the present utility model should be covered within the protection scope of the present utility model.

Claims

1. A coupled water meter automatic calibration device, characterized in that: It comprises a piston-type main standard device, the water outlet of which is installed with a piston water outlet valve and connected with the water inlet of the calibration station pipeline section, the calibration station pipeline section is used to install a plurality of water meters to be tested in series, and a collection terminal is arranged above each water meter to be tested; the water outlet of the calibration station pipeline section is respectively connected with one end of the first flow switching valve, the second flow switching valve and the third flow switching valve, the other end of the first flow switching valve is connected with one end of the first flow meter, the other end of the second flow switching valve is connected with one end of the second flow meter, the other end of the third flow switching valve is connected with one end of the third flow meter The other ends of the first flow meter and the second flow meter are connected to the water tank, the other end of the third flow meter is connected to the working volume meter through the reversing valve, the water outlet of the working volume meter is provided with a drain valve and connected to the water tank, and the working volume meter is placed on the electronic scale; the water outlet of the water tank is connected to one end of the piston return valve, and the other end of the piston return valve is connected to the return port of the piston type main standard; the water outlet of the water tank is also connected to one end of the water pump inlet valve, and the other end of the water pump inlet valve is connected to the water inlet of the water pump, and the water outlet of the water pump is connected to the pipeline connecting the piston outlet valve and the water inlet of the calibration station pipeline section.

2. The coupled water meter automatic calibration device according to claim 1, characterized in that: It also includes a meter clamp, which is used to clamp a plurality of inspected water meters installed in series.

3. The coupled water meter automatic calibration device according to claim 1, characterized in that: It also includes a pressure-stabilizing container, the water inlet of the pressure-stabilizing container is connected to the water outlet of the water pump, the water outlet of the pressure-stabilizing container is connected to one end of the pressure-stabilizing container outlet valve, and the other end of the pressure-stabilizing container outlet valve is connected to the pipeline connecting the piston water outlet valve and the water inlet of the calibration station pipeline section.

4. The coupled water meter automatic calibration device according to claim 1, characterized in that: An inlet pressure sensor and an inlet temperature sensor are also installed in the pipeline connecting the piston water outlet valve and the water inlet of the calibration station pipeline section.

5. The coupled water meter automatic calibration device as claimed in claim 4, characterized in that: An outlet pressure sensor and an outlet temperature sensor are also provided at the water outlet of the calibration station pipeline section.

6. The coupled water meter automatic calibration device according to claim 1, characterized in that: A filter screen is also installed in the water tank.

7. The coupled water meter automatic calibration device according to claim 1, characterized in that: The acquisition terminal is an industrial camera or a smart phone.

8. The coupled water meter automatic calibration device according to claim 1, characterized in that: The piston-type main standard includes a piston cylinder and a piston installed in the piston cylinder. The piston is connected to a ball screw, and the ball screw is driven to move by a motor. A grating ruler is also arranged on one side of the ball screw. The piston cylinder is provided with a water outlet and a water return port.

9. The coupled water meter automatic calibration device according to claim 1, characterized in that: The first flow meter, the second flow meter and the third flow meter are all float flow meters.

Images