CN113758545A - Four-valve piston type dynamic flow metering standard device and metering method - Google Patents
Four-valve piston type dynamic flow metering standard device and metering method Download PDFInfo
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- CN113758545A CN113758545A CN202111113636.3A CN202111113636A CN113758545A CN 113758545 A CN113758545 A CN 113758545A CN 202111113636 A CN202111113636 A CN 202111113636A CN 113758545 A CN113758545 A CN 113758545A
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Abstract
The invention provides a four-valve piston type dynamic flow metering standard device and a metering method, wherein the device comprises the following components: industrial computer, motor, lead screw, grating chi, piston cylinder, water tank, first pipeline, second pipeline and school volume pipeline. The industrial personal computer is electrically connected with the detected flowmeter, the motor, the first valve, the second valve, the third valve, the fourth valve and the grating ruler and is used for acquiring the displacement of the grating ruler and the data of the detected flowmeter in real time, controlling the motor to rotate and opening and closing the first valve, the second valve, the third valve and the fourth valve. The invention controls the pulse displacement of the piston in the piston cylinder by the industrial personal computer, and the pulsating flow always exists in the metering pipeline where the detected flowmeter is located by the arrangement of the piston cylinder, the water tank, the first pipeline, the second pipeline, the valves and the metering pipeline, so that the amplitude and the frequency of the pulsating flow can be adjusted in real time, the precision of the detected flowmeter under a dynamic flow signal is detected, and the instantaneous liquid volume flow value can be displayed in real time.
Description
Technical Field
The invention relates to the technical field of mechanical design and flow detection, in particular to a four-valve piston type dynamic flow metering standard device and a metering method.
Background
The existing piston type device is mostly used for a static flow standard device, and a piston type water meter calibrating device (patent number: 202021284357.4) the utility model has the advantages that the collected water is recycled by the water collecting tank, the screen, the water baffle, the water pump and the guide pipe which are arranged, the water resource is greatly saved, and the water meters with different sizes are calibrated by the arranged support rod, the flow detector, the sliding chute, the sliding block and the air cylinder when in use, so that the piston type water meter calibrating device is practical and suitable for wide popularization and use; an on-line measuring method (patent number: 201911195783.2) for the effective volume of piston cylinder in piston-type gas flow standard device includes such steps as periodically calibrating the volume in the service period of piston-type gas flow, measuring the moving distance of piston by laser interferometer, and measuring the internal diameter of piston cylinder by confocal spectrum measuring technique and external diameter to obtain the effective volume of piston cylinder. Therefore, the periodic calibration of the volume of the piston cylinder can be simplified, the online measurement of the volume of the piston cylinder can be completed on the premise of not disassembling the piston cylinder, and the device has the advantages of high measurement precision and convenience in calibration. An active plunger type liquid flow standard device (patent number: 202021228373.1) which is provided with a fixed plate, a connecting groove, a connecting rod, a first return spring, a rotating shaft and a moving plate, and can prevent the return spring from being clamped, thereby ensuring the stable operation of the whole device; the utility model provides a two-way active piston liquid flow standard device (patent No. 201620976475.9), this utility model's an aim at overcome prior art's not enough, provide a compact structure, range scope is big, can measure a two-way active piston liquid flow standard device for a long time in succession. A flow calibration device (patent No. 202021685210.6) which performs the calibration functions of multiple pipelines of the prior art, occupies only one station, and uses fewer connecting pipes.
The above flow standard devices are designed by using piston structures. The principle is that the displacement in a certain time is measured by utilizing the movement of the piston, and meanwhile, the displacement of the piston movement is measured by some optical measuring equipment in an auxiliary mode, and the measurement on the aspect of piston stroke accuracy is improved. And the flow metering standard device in other aspects is mainly innovation and improvement on the structure, so that the structure is more precise, the performance is more stable, and the measuring range is larger. But the design of the dynamic flow metering device is few and few.
Disclosure of Invention
The invention aims to provide a four-valve piston type dynamic flow metering standard device to solve the problem that the conventional standard device is difficult to calibrate a detected flowmeter under dynamic flow.
One of the objects of the invention is achieved by: a four-valve piston type dynamic flow metering calibration device, comprising:
the industrial personal computer is electrically connected with the detected flowmeter, the motor, the first valve, the second valve, the third valve, the fourth valve and the grating ruler and is used for acquiring the displacement of the grating ruler and the data of the detected flowmeter in real time, controlling the motor to rotate and opening and closing the first valve, the second valve, the third valve and the fourth valve;
the motor is controlled to rotate by the industrial personal computer;
the screw shaft is connected with an output shaft of the motor;
the grating ruler is fixed on a nut of the lead screw and used for measuring the displacement of the piston rod;
the piston rod is fixed on the nut of the screw rod, one side of the piston cylinder is provided with a vent hole, and the other end of the piston cylinder is provided with a piston port A and a piston port B;
the water tank is provided with a first water tank opening and a second water tank opening;
the first pipeline is connected between the piston port A and a first water tank port, a first valve and a second valve are arranged on the first pipeline, and a node X is arranged between the first valve and the second valve;
the second pipeline is connected between the piston port B and a second water tank port, a third valve and a fourth valve are arranged on the second pipeline, and a node Y is arranged between the third valve and the fourth valve; and
the calibration pipeline is provided with a to-be-tested flowmeter, one end of the calibration pipeline is connected to the node X, and the other end of the calibration pipeline is connected to the node Y;
further, the invention can be realized according to the following technical scheme:
the first valve and the second valve are both arranged at the node X end of the first pipeline.
And the third valve and the fourth valve are both arranged at the Y end of the node of the second pipeline.
And a pressure sensor and a temperature sensor are arranged on the calibration pipeline.
The motor is a servo motor, and the industrial personal computer controls the servo motor through the PLC and the servo driver.
The second purpose of the invention is to provide a method for measuring the dynamic flow of the four-valve piston type, so as to solve the problem that the dynamic flow is difficult to measure in real time by the existing method.
The second purpose of the invention is realized by the following steps: a four-valve piston dynamic flow metering method comprising the steps of:
a. providing a four-valve piston type dynamic flow metering standard device of claim 1;
b. the industrial personal computer sends a pulse signal to the motor, the motor controls a nut on the screw to drive the piston rod to move rightwards, meanwhile, the industrial personal computer records the displacement of a grating ruler on the nut in real time and controls a first valve and a fourth valve to be opened, the second valve and the third valve are closed, water extruded from the piston cylinder flows through the first valve on the first pipeline through a piston port A and then flows to the calibration pipeline through a node X, and water flows out of the calibration pipeline, flows through a node Y and then flows into the water tank through a second water tank port after flowing through the fourth valve on the second pipeline;
c. the industrial personal computer sends a pulse signal to the motor, the motor controls a nut on the screw to drive the piston rod to move leftwards, meanwhile, the industrial personal computer records the displacement of a grating ruler on the nut in real time and controls a second valve and a third valve to be opened, the first valve and the fourth valve are closed, water sucked out of the water tank flows to the calibration pipeline through a node X after flowing through the second valve on the first pipeline through a second water tank port, flows to the piston cylinder through a node Y after flowing through the third valve on the second pipeline from the calibration pipeline, and flows to the piston cylinder through a piston port B;
d. and D, repeating the processes of the step B and the step C to ensure that water flow always exists in the calibration pipeline where the detected flowmeter is located to obtain the displacement of the grating ruler, and calculating the volume flow of the liquid actually flowing through the piston cylinder by the industrial personal computer through the displacement of the grating ruler and comparing the volume flow with the measured flow of the detected flowmeter.
Further, the invention can be realized according to the following technical scheme:
in the step a, a pressure sensor and a temperature sensor are arranged on the calibration pipeline, and the temperature and pressure information of the liquid flowing through the detected flowmeter is detected and collected in real time.
The invention controls the pulse displacement of the piston in the piston cylinder by the industrial personal computer, and the pulsating flow always exists in the metering pipeline where the detected flowmeter is located by the arrangement of the piston cylinder, the water tank, the first pipeline, the second pipeline, the valves and the metering pipeline, so that the amplitude and the frequency of the pulsating flow can be adjusted in real time, the precision of the detected flowmeter under a dynamic flow signal is detected, and the instantaneous liquid volume flow value can be displayed in real time. The invention has the advantages of convenient use, real-time visible accuracy and more accurate, reasonable and effective measurement result. In order to improve the accuracy of measuring the piston displacement, the displacement of the piston is measured by a grating ruler.
The invention adopts the servo motor with better acceleration performance, and can carry out control of quick start-stop and change of rotating speed. Therefore, the upper computer software is used for compiling corresponding programs and sending instructions, so that the servo motor can quickly respond to action, the amplitude and the frequency can be controlled in real time, and the water flow with stable, continuous and adjustable flow is generated. The amplitude is adjusted by changing the rotating speed of the servo motor, and the frequency is adjusted by changing the starting and stopping of the servo motor. Thus, the flow waveform can be made to present a sinusoidal waveform, so as to check the dynamic performance of the detected flowmeter.
Specifically, when the piston moves to the right, the first valve and the fourth valve are opened, the second valve and the third valve are closed, water squeezed out of the piston cylinder enters the water tank through the first line, the second valve is arranged at the node X end of the first pipeline, and the third valve is arranged at the node Y end of the second pipeline, so that water is prevented from flowing into other pipelines through the node Y. When the piston moves leftwards, the first valve and the fourth valve are closed, the second valve and the third valve are opened, water sucked out of the water tank enters the piston cylinder through the second line, the first valve is arranged at the node X end of the first pipeline, the fourth valve is arranged at the node Y end of the second pipeline, and water is prevented from flowing into other pipelines when passing through the node X and the node Y, so that the measuring accuracy of the invention is improved to the maximum extent. Meanwhile, the pressure sensor and the temperature sensor are arranged on the calibration pipeline, so that the temperature and the pressure of water flow flowing through the calibration pipeline are detected and collected in real time, and the temperature and the pressure of the water flow are corrected as required, so that the measurement precision is improved.
Drawings
Fig. 1 is a schematic structural view of the present invention.
Fig. 2 is a control flow diagram of the present invention.
In the figure: 1. the device comprises a first valve, a second valve, a third valve, a fourth valve, a fifth valve, a sixth valve, a seventh valve, a sixth valve, a fourth valve, a sixth valve, a fourth valve, a sixth valve, a fourth valve, a sixth valve, a fourth valve, a sixth valve, a fourth valve, a sixth valve, a fourth valve, a sixth valve, a fourth valve, a sixth valve, a fourth valve, a sixth.
Detailed Description
Example 1
As shown in fig. 1, the present invention includes an industrial personal computer 5, a PLC17, a servo driver 18, a servo motor 6, a lead screw 12, a grating ruler 13, a piston cylinder 7, a water tank 8, a first pipeline 11, a second pipeline 10, a calibration pipeline 9, a first valve 1, a second valve 2, a third valve 3, a fourth valve 4, a pressure sensor 21 and a temperature sensor 22.
The industrial personal computer 5 is electrically connected with the detected flow meter 19, the motor 6, the first valve 1, the second valve 2, the third valve 3, the fourth valve 4, the pressure sensor 21, the temperature sensor 22 and the grating ruler 13, and is used for acquiring the displacement of the grating ruler 13, the data of the temperature sensor 22, the pressure sensor 21 and the detected flow meter 19 in real time, controlling the motor 6 to rotate, and opening and closing the first valve 1, the second valve 2, the third valve 3 and the fourth valve 4. The industrial personal computer 5 has stronger anti-interference performance, and can make the verification process more stable and reliable. The PLC17, the motor 6 and other data acquisition and process control equipment are purchased according to actual control requirements, and input and output control and data processing software is compiled according to related national verification regulations. The industrial personal computer 5 is connected with the detected flowmeter 19, and can acquire the reading on the detected flowmeter 19 in real time so as to compare the reading with the flow of the standard device.
The motor 6 is a servo motor 6, and the industrial personal computer 5 controls the PLC17 and the servo driver 18 to drive the motor. An output shaft of the servo motor 6 is connected with a lead screw 12 shaft of a lead screw 12, a nut 14 of the lead screw 12 is provided with a grating ruler 13 and a piston rod 15 of a piston cylinder 7, and the lead screw 12 converts the rotary motion of the servo motor 6 with amplitude and frequency into linear motion with amplitude and frequency. The grating ruler 13 is used for measuring the displacement of the piston rod 15, namely the piston, the reading head is arranged on the grating ruler 13, the reading head moves along with the piston rod 15, and the displacement of the reading head movement is transmitted to the industrial personal computer 5 through the I/O port for data processing. In order to improve the measurement accuracy, two grating scales 13 symmetrically mounted on the screw 12 may be provided, and the displacement of the piston is an average value of the displacements measured by the two grating scales 13 within the measurement time. On the other hand, the results measured by the two grating rulers 13 can be compared, so that whether the grating rulers 13 count correctly or not can be found in time. By comprehensive consideration, the effective length of the selected grating ruler 13 is 1.42m, and the precision is +/-5 um. The servo motor 6 has the characteristics of large starting torque, wide operating range, no autorotation phenomenon, high positioning precision and the like, and is widely applied to various automatic control systems.
A piston rod 15 of the piston cylinder 7 is fixed on a nut 14 of the screw rod, a vent hole 16 is arranged on one side of the piston cylinder 7 so as to facilitate the smooth movement of the piston, and a piston port A and a piston port B are arranged on the other end of the piston cylinder 7.
A first water tank opening 23 and a second water tank opening 24 are formed in the water tank 8, the water tank 8 is communicated with the piston cylinder 7 through a first pipeline 11 and a second pipeline 10, the first pipeline 11 is connected between the piston opening A and the first water tank opening 23, a first valve 1 and a second valve 2 are arranged on the first pipeline 11, and a node X is arranged between the first valve 1 and the second valve 2; the first valve 1 and the second valve 2 are both arranged at the node X end of the first pipeline 11.
The second pipe 10 is connected between the piston port B and the second tank port 24, the third valve 3 and the fourth valve 4 are provided on the second pipe 10, and the node Y is provided between the third valve 3 and the fourth valve 4. The third valve 3 and the fourth valve 4 are both arranged at the node Y end of the second pipeline 10.
The calibration pipe 9 is provided with a flow meter 19 to be tested, a pressure sensor 21, and a temperature sensor 22 by a meter clamper 20. One end of the calibration pipeline 9 is connected to the node X, and the other end of the calibration pipeline is connected to the node Y. The temperature sensor 22 and the pressure sensor 21 are used for measuring the temperature and the pressure of the liquid respectively, so that information is transmitted to the PLC17 in time and transmitted to the industrial personal computer 5 by the PLC 17. The meter clamper 20 can adjust the pitch according to the length of the flow meter 19 to be tested. The test pipeline is arranged to meet the clamping requirements of the detected flowmeter 19, and the upstream straight pipe section is generally specified to be not less than 10 times of the caliber of the detected flowmeter 19, and the downstream straight pipe section is generally specified to be not less than 5 times of the caliber of the detected flowmeter 19.
The principle of the industrial personal computer 5 for calculating the actual liquid volume flow q is as follows: the volume flow q of the liquid flowing through the piston cylinder 7 is equal to the product of the sectional area A of the piston cylinder 7 and the average flow velocity v of the measured liquid.
The mathematical model of the standard device can be simplified to:
wherein q is the liquid volume flow; a is the sectional area of the piston cylinder 7; v-instantaneous volume flow; l-piston displacement distance; t is a time unit; d is the inner diameter of the piston cylinder 7.
The displacement of the piston can be obtained through the displacement signal transmitted by the grating ruler 13, and the sectional area A of the piston cylinder 7 is calculated through the displacement of the piston, so that the volume flow q of the liquid flowing through the piston cylinder 7 in the displacement can be obtained. Meanwhile, the time for the displacement of the section of piston is recorded by using the clock function of the PLC17, so that the average flow velocity of the measured liquid calculated by the industrial personal computer 5 can be obtained, namely, the displacement of the piston rod 15 is fed back to the PLC17 and the industrial personal computer 5 by the grating ruler 13 in real time, and the real-time liquid volume flow of the invention is obtained after the industrial personal computer 5 calculates. The industrial personal computer 5 is connected with the detected flowmeter 19, and can acquire and display the reading on the detected flowmeter 19 in real time so as to compare with the actual liquid volume flow value of the invention. By comparing data, the estimation of measurement error and measurement uncertainty is reasonably carried out, the influence of the measurement error on the measurement result is reduced, the measurement accuracy is improved, and meanwhile, a dynamic flow measurement instrument is scientifically and reasonably selected and designed by applying an error theory.
Example 2
A four-valve piston dynamic flow metering method, as shown in fig. 1 and 2, comprising the steps of:
a. in the four-valve piston type dynamic flow rate measuring standard device in embodiment 1, a pressure sensor 21 and a temperature sensor 22 are arranged on the calibration pipeline 9, and the temperature and pressure information of the liquid flowing through the detected flow meter 19 is detected and collected in real time.
b. The industrial personal computer 5 sends a pulse signal to the motor 6, the motor 6 controls the screw 14 on the screw rod 12 to drive the piston rod 15 to move rightwards, meanwhile, the industrial personal computer 5 records the displacement of the grating ruler 13 on the screw 14 in real time and controls the first valve 1 and the fourth valve 4 to be opened, the second valve 2 and the third valve 3 are closed, water extruded out of the piston cylinder 7 flows through the piston opening A, flows to the calibration pipeline 9 through the node X after flowing through the first valve 1 on the first pipeline 11, flows out of the calibration pipeline 9 through the node Y, flows to the fourth valve 4 on the second pipeline 10, and flows into the water tank 8 through the second water tank opening 24.
c. The industrial personal computer 5 sends a pulse signal to the motor 6, the motor 6 controls the screw 14 on the screw rod 12 to drive the piston rod 15 to move leftwards, meanwhile, the industrial personal computer 5 records the displacement of the grating ruler 13 on the screw 14 in real time and controls the second valve 2 and the third valve 3 to be opened, the first valve 1 and the fourth valve 4 are closed, water sucked out of the water tank 8 flows through the second valve 2 on the first pipeline 11 through the second water tank port 24 and then flows to the calibration pipeline 9 through the node X, and water flows out of the calibration pipeline 9 and flows through the third valve 3 on the second pipeline 10 through the node Y and then flows into the piston cylinder 7 through the piston port B.
d. And repeating the processes of the step B and the step C to ensure that water flow always exists in the calibration pipeline 9 where the detected flowmeter 19 is located to obtain the displacement of the grating ruler 13, and the industrial personal computer 5 calculates the volume flow of the liquid actually flowing through the piston cylinder 7 according to the displacement of the grating ruler 13 and compares the volume flow with the measured flow of the detected flowmeter 19. By comparing data, the estimation of measurement error and measurement uncertainty is reasonably carried out, the influence of the measurement error on the measurement result is reduced, the measurement accuracy is improved, and meanwhile, a dynamic flow measurement instrument is scientifically and reasonably selected and designed by applying an error theory.
Claims (7)
1. The utility model provides a four valve piston dynamic flow measurement standard device, characterized by includes:
the industrial personal computer is electrically connected with the detected flowmeter, the motor, the first valve, the second valve, the third valve, the fourth valve and the grating ruler and is used for acquiring the displacement of the grating ruler and the data of the detected flowmeter in real time, controlling the motor to rotate and opening and closing the first valve, the second valve, the third valve and the fourth valve;
the motor is controlled to rotate by the industrial personal computer;
the screw shaft is connected with an output shaft of the motor;
the grating ruler is fixed on a nut of the lead screw and used for measuring the displacement of the piston rod;
the piston rod is fixed on the nut of the screw rod, one side of the piston cylinder is provided with a vent hole, and the other end of the piston cylinder is provided with a piston port A and a piston port B;
the water tank is provided with a first water tank opening and a second water tank opening;
the first pipeline is connected between the piston port A and a first water tank port, a first valve and a second valve are arranged on the first pipeline, and a node X is arranged between the first valve and the second valve;
the second pipeline is connected between the piston port B and a second water tank port, a third valve and a fourth valve are arranged on the second pipeline, and a node Y is arranged between the third valve and the fourth valve; and
and the volume correcting pipeline is provided with a detected flow meter, one end of the volume correcting pipeline is connected to the node X, and the other end of the volume correcting pipeline is connected to the node Y.
2. A four-valve piston-type dynamic flow metering gauge device as claimed in claim 1, wherein said first and second valves are disposed at said node X end of said first conduit.
3. A four-valve piston-type dynamic flow metering gauge device as claimed in claim 1, wherein said third and fourth valves are disposed at the Y-end of the node of the second conduit.
4. A four-valve piston type dynamic flow metering standard device according to claim 1, wherein a pressure sensor and a temperature sensor are arranged on the calibration pipe.
5. The four-valve piston type dynamic flow metering standard device as claimed in claim 1, wherein the motor is a servo motor, and the industrial personal computer controls the servo motor through a PLC and a servo driver.
6. A four-valve piston type dynamic flow metering method is characterized by comprising the following steps:
a. providing a four-valve piston type dynamic flow metering standard device of claim 1;
b. the industrial personal computer sends a pulse signal to the motor, the motor controls a nut on the screw to drive the piston rod to move rightwards, meanwhile, the industrial personal computer records the displacement of a grating ruler on the nut in real time and controls a first valve and a fourth valve to be opened, the second valve and the third valve are closed, water extruded from the piston cylinder flows through the first valve on the first pipeline through a piston port A and then flows to the calibration pipeline through a node X, and water flows out of the calibration pipeline, flows through a node Y and then flows into the water tank through a second water tank port after flowing through the fourth valve on the second pipeline;
c. the industrial personal computer sends a pulse signal to the motor, the motor controls a nut on the screw to drive the piston rod to move leftwards, meanwhile, the industrial personal computer records the displacement of a grating ruler on the nut in real time and controls a second valve and a third valve to be opened, the first valve and the fourth valve are closed, water sucked out of the water tank flows to the calibration pipeline through a node X after flowing through the second valve on the first pipeline through a second water tank port, flows to the piston cylinder through a node Y after flowing through the third valve on the second pipeline from the calibration pipeline, and flows to the piston cylinder through a piston port B;
d. and D, repeating the processes of the step B and the step C to ensure that water flow always exists in the calibration pipeline where the detected flowmeter is located to obtain the displacement of the grating ruler, and calculating the volume flow of the liquid actually flowing through the piston cylinder by the industrial personal computer through the displacement of the grating ruler and comparing the volume flow with the measured flow of the detected flowmeter.
7. A four-valve piston type dynamic flow measuring method as claimed in claim 6, wherein in step a, a pressure sensor and a temperature sensor are arranged on the measuring pipeline, and the temperature and pressure information of the liquid flowing through the measured flow meter are detected and collected in real time.
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| CN202111113636.3A CN113758545A (en) | 2021-09-23 | 2021-09-23 | Four-valve piston type dynamic flow metering standard device and metering method |
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| CN202111113636.3A CN113758545A (en) | 2021-09-23 | 2021-09-23 | Four-valve piston type dynamic flow metering standard device and metering method |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN203643006U (en) * | 2013-11-22 | 2014-06-11 | 西安航天计量测试研究所 | Standard colloid flow meter device |
| CN103940496A (en) * | 2014-04-21 | 2014-07-23 | 杭州宏量科技有限公司 | Small liquid flow standard device special for hemodialysis machine calibrator |
| CN206074091U (en) * | 2016-08-29 | 2017-04-05 | 天津市计量监督检测科学研究院 | A kind of two-way active piston liquid flow standard device |
| CN216206874U (en) * | 2021-09-23 | 2022-04-05 | 河北大学 | Four-valve piston type dynamic flow metering standard device |
-
2021
- 2021-09-23 CN CN202111113636.3A patent/CN113758545A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN203643006U (en) * | 2013-11-22 | 2014-06-11 | 西安航天计量测试研究所 | Standard colloid flow meter device |
| CN103940496A (en) * | 2014-04-21 | 2014-07-23 | 杭州宏量科技有限公司 | Small liquid flow standard device special for hemodialysis machine calibrator |
| CN206074091U (en) * | 2016-08-29 | 2017-04-05 | 天津市计量监督检测科学研究院 | A kind of two-way active piston liquid flow standard device |
| CN216206874U (en) * | 2021-09-23 | 2022-04-05 | 河北大学 | Four-valve piston type dynamic flow metering standard device |
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