A standard device for a rotameter with automatic back pressure check

Abstract

The application relates to a rotor flowmeter standard device with an automatic back difference inspection function, which comprises a standard table for a flow reference, the standard table is connected with a first switch valve through a pipeline, the first switch valve is connected with a measured rotor flowmeter through a pipeline, the measured rotor flowmeter is connected with an upstroke flow regulating valve FVH in parallel through a pipeline, the measured rotor flowmeter is connected with a main regulating valve in series through a pipeline, the main regulating valve is connected with a downstroke flow regulating valve FVL in parallel through a pipeline, and the main regulating valve is provided with a control unit for fast and accurate control of the main regulating valve. Through a clever parallel valve system, local disturbance of the flow at the measured rotor flowmeter is realized, the float of the measured rotor flowmeter is caused to generate upstroke and downstroke movement, the back difference is directly read out, the back difference measurement is changed from 'dynamic tracking' to'static observation', and the measurement result is more accurate.

Description

Technical Field

[0001] This application relates to the field of fluid measurement technology, and in particular to a standard device for a rotor flowmeter with automatic hysteresis verification function. Background Technology

[0002] Rotor flow meters, as a common flow measurement device, are widely used in industries such as chemical, petroleum, and pharmaceutical. Due to internal mechanical friction (such as the friction between the shaft and the bore), the indicated value of a rotor flow meter (float flow meter) may differ during flow increases and decreases, even for the same actual flow rate. This difference is called "hysteresis" (or backlash error). Therefore, metrological verification procedures explicitly require hysteresis testing of rotor flow meters.

[0003] Traditional testing methods involve manually or automatically adjusting the valve to find the "upper stroke" and "lower stroke" flow points that make the flow meter readings the same. However, in practice, it is extremely difficult to precisely stabilize the flow rates of the two adjustments at exactly the same value. This results in repeated adjustments during the testing process, which is time-consuming and labor-intensive. It also requires human judgment and adjustment, and the adjustment deviation can affect the accuracy of the hysteresis measurement. Summary of the Invention

[0004] To address the problem that in practical operation of existing technologies, it is extremely difficult to accurately stabilize the flow rate of two adjustments at exactly the same value, which leads to repeated adjustments during the testing process, is time-consuming and labor-intensive, requires manual judgment and adjustment, and causes adjustment deviations to affect the accuracy of hysteresis measurement, this application provides a standard device for rotor flowmeters with automatic hysteresis testing function.

[0005] This application provides a standard device for a rotor flowmeter with automatic hysteresis testing function, which adopts the following technical solution: A standard device for a rotor flowmeter with automatic hysteresis verification function includes a standard meter for flow reference. The standard meter is connected to a first switching valve via a pipe. The first switching valve is connected to the rotor flowmeter under test via a pipe. The rotor flowmeter under test is connected in parallel to an upper stroke flow regulating valve FVH via a pipe. The rotor flowmeter under test is connected in series to a main regulating valve via a pipe. The main regulating valve is connected in parallel to a lower stroke flow regulating valve FVL via a pipe. The main regulating valve is equipped with a control unit for rapid and precise control of the main regulating valve. The control unit adopts PID control algorithm and fuzzy algorithm.

[0006] By adopting the above technical solution, the total flow rate of the pipeline is quickly adjusted and stabilized at a required calibration point by controlling the opening and closing of the main regulating valve. This flow rate is then measured by a standard gauge, stabilizing the float on the tested rotameter at a certain height and indicating an initial value. During the upper stroke measurement, the system uniformly opens the upper stroke flow regulating valve FVH connected in parallel across the tested rotameter. This provides a bypass for the fluid flowing through the tested rotameter, causing the flow rate to decrease slowly, and the float to descend accordingly. After the upper stroke flow regulating valve FVH opens to a certain degree, the system uniformly closes it. During the closing process, the bypass flow decreases, and the flow rate through the tested rotameter slowly increases, causing the float to rise until the upper stroke flow regulating valve FVH is completely closed. The flow rate through the tested rotameter then returns to its initial stable value, which is the upper stroke indicated value. During the downstroke measurement, the system opens the downstroke flow control valve FVL, which is connected in parallel across the main control valve, at a constant speed. This provides an additional bypass to the main control valve, causing a slight change in the flow and pressure in the main path (through the main control valve and the tested rotameter). The flow rate through the tested rotameter increases slowly, and its float rises accordingly. After the downstroke flow control valve FVL opens to a certain degree, the system closes it at a constant speed. During the closing process, the flow rate through the tested rotameter decreases slowly, and the float falls accordingly until the downstroke flow control valve FVL is completely closed. The flow rate through the tested rotameter returns to its initial stable value, which is the downstroke indication value. The hysteresis value is obtained by calculating hysteresis = |upper stroke value - lower stroke value|, which facilitates operation, avoids repeated adjustments, ensures testing accuracy, and makes the hysteresis measurement results more accurate. At the same time, by using PID control algorithm and fuzzy algorithm, fast and precise control of the main control valve is achieved.

[0007] Preferably, when the main regulating valve is installed at the inlet position of the rotor flowmeter under test, the first switching valve is located between the standard meter and the rotor flowmeter under test, and the rotor flowmeter under test is located between the first switching valve and the main regulating valve.

[0008] By adopting the above technical solution, the upper stroke flow regulating valve FVH is connected in parallel with the meter under test. When the main regulating valve is at the inlet, the flow regulation of the upper stroke flow regulating valve FVH can directly change the flow increment entering the meter under test. In conjunction with the main regulating valve, it can achieve a smoother flow increase process and avoid reading deviation of the meter under test caused by sudden flow changes. The lower stroke flow regulating valve FVL is connected in parallel with the main regulating valve. The main regulating valve at the inlet can directly reduce the flow entering the meter under test by closing it slightly. The auxiliary regulation of the lower stroke flow regulating valve FVL can further refine the gradient of flow decrease, ensure stable decay of the flow in the lower stroke, and reduce data fluctuations in hysteresis testing.

[0009] Preferably, when the main regulating valve is installed at the outlet position of the rotor flowmeter under test, the main regulating valve is installed between the rotor flowmeter under test and the standard meter.

[0010] By adopting the above technical solution, the main regulating valve is located at the outlet end of the meter under test. All regulating actions (such as flow rate increase or decrease) act downstream of the meter under test, without changing the stability of the pressure and flow rate at its inlet end. This avoids frequent fluctuations of the float due to upstream regulation, improving the stability of the meter reading. For small-range, high-precision rotor flowmeters that are sensitive to inlet pressure, this layout can significantly reduce pressure shocks during regulation and reduce inspection errors caused by pressure fluctuations. At the same time, with the main regulating valve at the outlet end, the back pressure of the downstream pipeline can be controlled by the valve opening, accurately simulating the working environment of the meter under test in actual applications. This ensures that the inspection results are consistent with the actual usage conditions. There is no need to install an additional back pressure valve. Flow regulation and back pressure control can be achieved simultaneously through the main regulating valve, simplifying the system structure and reducing equipment costs and pipeline complexity.

[0011] Preferably, the standard gauges are set in multiple groups, and the range of each standard gauge is different. The multiple groups of standard gauges are connected to multiple second switching valves through pipelines, so as to match the upper or lower stroke flow monitoring of different flow ranges by switching the second switching valves.

[0012] By adopting the above technical solution, the upper / lower stroke reference is customized and the range is complementary through multiple sets of standard gauges. Combined with the independent on / off control capability of the second switching valve, the pain points of accuracy and efficiency of traditional single gauges are solved, and the system safety and scalability are improved.

[0013] Preferably, the standard meter is an electromagnetic flowmeter with an accuracy higher than 0.3.

[0014] By adopting the above technical solution and selecting an electromagnetic flowmeter with an accuracy higher than 0.3 as the standard meter, not only can the core requirement of "high-precision benchmark" for rotor flowmeter calibration be met, but also the application scenarios of the device can be expanded, maintenance costs reduced, and automation levels improved through its excellent fluid adaptability, stability, and intelligent characteristics.

[0015] Preferably, the main regulating valve is a V-type flow regulating valve with valve position feedback.

[0016] By adopting the above technical solution and selecting a V-type flow regulating valve with valve position feedback as the main regulating valve, not only can the core requirement of "full-range high-precision flow control" for rotor flowmeter calibration be met, but also the system's stability and anti-interference ability can be improved through closed-loop control, fast response, pressure compensation and other characteristics. At the same time, it can be seamlessly integrated into the automated calibration system and reduce long-term maintenance costs.

[0017] In summary, this application includes at least one of the following beneficial technical effects: 1. This utility model abandons the traditional approach of "adjusting the flow rate to align with the indicated value" and innovatively adopts the reverse thinking of "fixing the standard flow rate and measuring the flow meter indication value". Through a clever parallel valve system, the flow rate at the rotor flow meter being measured is locally disturbed, causing the float to move up and down, thereby directly reading its hysteresis. This solves the core problem of "difficulty in aligning the two flow rates" in the traditional method, and changes the hysteresis measurement from "dynamic tracking" to "static observation", making the measurement results more accurate. 2. This utility model achieves automated hysteresis inspection through the coordinated control of parallel regulating valves and standard gauges, significantly improving inspection efficiency. At the same time, it adopts PID and fuzzy algorithms to quickly stabilize the flow rate value and ensure the accuracy of the inspection results. 3. This utility model uses parallel regulating valves and standard gauges for coordinated control. It has a simple structure, is suitable for testing liquid and gas flow meters, has strong versatility, and the design of the uniform speed regulating valve effectively avoids flow fluctuations and improves the reliability of dynamic testing. Attached Figure Description

[0018] Figure 1 This is a schematic diagram showing the main regulating valve installed at the inlet of the rotor flowmeter being measured; Figure 2 This is a schematic diagram showing the main regulating valve installed at the outlet of the rotor flowmeter being measured. Figure 3 This is a schematic diagram of the installation process for using multiple sets of standard meters in parallel.

[0019] Reference numerals in the attached diagram: 1. Standard gauge; 2. First switching valve; 3. Flow meter under test; 4. Upper stroke flow regulating valve FVH; 5. Main regulating valve; 6. Lower stroke flow regulating valve FVL; 7. Control unit; 8. Second switching valve; 9. Pressure stabilizing tank; 10. Pump body. Detailed Implementation

[0020] The following is in conjunction with the appendix Figure 1 -Appendix Figure 3 This application will be described in further detail.

[0021] This application discloses a standard device for a rotor flowmeter with automatic hysteresis testing function.

[0022] Reference Figure 1 and Figure 2A standard device for a rotor flowmeter with automatic hysteresis testing function includes a standard meter 1, which provides an accurate and stable flow reference. The standard meter 1 is connected to a first switching valve 2 via a pipe. The first switching valve 2 is connected to the rotor flowmeter under test 3 via a pipe. The end of the rotor flowmeter under test 3 away from the first switching valve 2 is connected in series with a main regulating valve 5 via a pipe. The rotor flowmeter under test is connected in parallel with an upper stroke flow regulating valve FVH4 via a pipe. The main regulating valve 5 is connected in parallel with a lower stroke flow regulating valve FVL6 via a pipe. The main regulating valve 5 is equipped with a control unit 7 for rapid and accurate control of the main regulating valve 5. The control unit 7 adopts a PID control algorithm and a fuzzy algorithm.

[0023] Specifically, standard meter 1 uses an electromagnetic flowmeter with an accuracy higher than 0.3, installed on the main pipeline; a pressure stabilizing tank 9 and a pump body 10 are installed on the main pipeline, so that the pressure stabilizing tank 9 stabilizes the pressure fluctuations generated by the pump body 10, thus stabilizing the flow rate entering the main regulating valve 5. The main regulating valve 5 is a V-type flowmeter regulating valve with valve position feedback function, installed downstream of standard meter 1; the upper stroke flow regulating valve FVH4 is connected in parallel with the measured rotor flowmeter 3, and the lower stroke flow regulating valve FVL6 is connected in parallel with the main regulating valve 5. The system monitors the flow value of standard meter 1 and uses PID control algorithm and fuzzy algorithm to quickly set the flow value of the test point. When setting the flow rate, keep both parallel flow control valves fully closed. After setting the flow rate value and waiting for it to stabilize, when measuring the upper stroke value, the system uniformly opens the upper stroke flow control valve FVH4 connected in parallel across the rotor flowmeter 3 being measured. This provides a bypass for the fluid in the rotor flowmeter 3, causing the flow rate through the rotor flowmeter 3 to decrease slowly, and its float to drop accordingly. After the upper stroke flow control valve FVH4 is opened to a certain degree, the system then uniformly closes the upper stroke flow control valve FVH4. During the closing process, the bypass flow decreases, and the flow rate through the rotor flowmeter 3 increases slowly again. The float rises until the upper stroke flow regulating valve FVH4 is completely closed, and the flow rate through the measured rotor flowmeter 3 returns to its initial stable value. After the flow rate stabilizes, the operator or image recognition system records the indicated value or signal value of the scale line of the measured rotor flowmeter 3, which is the upper stroke indication value. When measuring the lower stroke value, the system opens the lower stroke flow regulating valve FVL6 connected in parallel across the main regulating valve 5 at a uniform speed. This provides an additional bypass to the main regulating valve 5, causing a change in the flow pressure through the main regulating valve 5 and the measured rotor flowmeter 3. The flow rate through the measured rotor flowmeter 3 will slowly increase, and its float... The float rises accordingly; after the lower stroke flow regulating valve FVL6 is opened to a certain degree, the system closes it at a constant speed. During the closing process, the flow rate through the measured rotor flowmeter 3 slowly decreases, and the float falls accordingly until the lower stroke flow regulating valve FVL6 is completely closed, and the system returns to the initial stable state. After the flow rate stabilizes, the operator or image recognition system records the indicated value or signal value of the rotor flowmeter scale line, which is the lower stroke indicated value. Finally, the hysteresis is calculated using the formula "hysteresis = |upper stroke value - lower stroke value|", which facilitates operation, avoids repeated adjustments, ensures inspection accuracy, and makes the hysteresis measurement results more accurate.

[0024] refer to Figure 1 When the main regulating valve 5 is installed at the inlet of the rotor flowmeter 3 under test, one end of the first switching valve 2 is connected to the standard meter 1 through a pipe, and the other end of the first switching valve 2 is connected to the rotor flowmeter 3 under test through a pipe. The end of the rotor flowmeter 3 under test away from the first switching valve 2 is connected to the main regulating valve 5.

[0025] Using the above scheme, the upper stroke flow regulating valve FVH4 is connected in parallel with the meter under test. When the main regulating valve 5 is at the inlet, the flow regulation of the upper stroke flow regulating valve FVH4 can directly change the flow increment entering the meter under test. In conjunction with the main regulating valve 5, it can achieve a smoother flow increase process and avoid reading deviations of the meter under test caused by sudden flow changes. The lower stroke flow regulating valve FVL6 is connected in parallel with the main regulating valve 5. The main regulating valve 5 at the inlet can directly reduce the flow entering the meter under test by closing it slightly. The auxiliary regulation of the lower stroke flow regulating valve FVL6 can further refine the gradient of flow decrease, ensure stable decay of the flow in the lower stroke, and reduce data fluctuations in hysteresis testing.

[0026] refer to Figure 2 When the main regulating valve 5 is installed at the outlet position of the rotor flowmeter 3 under test, one end of the main regulating valve is connected to the standard meter 1 through a pipe, and the other end of the main regulating valve 5 is connected to the rotor flowmeter 3 under test through a pipe. The end of the rotor flowmeter 3 under test that is away from the main regulating valve 5 is connected to the first switching valve 2 through a pipe, so that the rotor flowmeter 3 under test and the main regulating valve 5 are located between the standard meter 1 and the first switching valve 2.

[0027] With the above scheme, the main regulating valve 5 is located at the outlet end of the rotor flowmeter 3 under test. All regulating actions (such as flow rate increase or decrease) act downstream of the measured meter, without changing the pressure and flow stability at its inlet end. This avoids frequent fluctuations of the float due to upstream regulation, improving the stability of the measured meter reading. For the small-range, high-precision rotor flowmeter 3 that is sensitive to inlet pressure, this layout can significantly reduce pressure shocks during regulation and reduce inspection errors caused by pressure fluctuations. At the same time, with the main regulating valve 5 at the outlet end, the back pressure of the downstream pipeline can be controlled by the valve opening, accurately simulating the working environment of the rotor flowmeter 3 under test in actual applications. This ensures that the inspection results are consistent with the actual usage conditions. There is no need to install an additional back pressure valve. Flow regulation and back pressure control can be achieved simultaneously through the main regulating valve 5, simplifying the system structure and reducing equipment costs and pipeline complexity.

[0028] refer to Figure 1 and Figure 2 Standard Gauge 1 uses an electromagnetic flowmeter with an accuracy class of not less than 0.3; the main regulating valve 5 is a V-type flow regulating valve, and the V-type flow regulating valve is an electric regulating valve with valve position feedback function; the upper stroke flow regulating valve FVH4 and the lower stroke flow regulating valve FVL6 are uniform speed regulating electric valves with a response time of less than 0.5 seconds. Standard Gauge 1 can be replaced with other high-precision flowmeters, such as ultrasonic flowmeters; the regulating valves can be replaced with pneumatic or hydraulic driven types, but the uniform speed regulating function must be guaranteed.

[0029] By adopting the above scheme, an electromagnetic flowmeter with an accuracy higher than 0.3 is selected as the standard table 1. This not only meets the core requirement of "high-precision benchmark" for rotor flowmeter calibration, but also expands the application scenarios of the device, reduces maintenance costs, and improves the level of automation through its excellent fluid adaptability, stability, and intelligent characteristics. At the same time, a V-type flow regulating valve with valve position feedback is selected as the main regulating valve 5. This not only meets the core requirement of "full-range high-precision flow control" for the calibration of the rotor flowmeter 3 under test, but also improves the stability and anti-interference ability of the system through closed-loop control, fast response, and pressure compensation characteristics. Meanwhile, it is seamlessly integrated into the automated calibration system, reducing long-term maintenance costs.

[0030] refer to Figure 3 Meanwhile, this scheme can adopt a parallel design of multiple sets of standard gauges 1, with different ranges for each set of standard gauges, so that they can monitor the flow values ​​of the upper and lower strokes respectively. During measurement, the first switch valve 2 and the second switch valve 8 at the inlet of the multiple sets of standard gauges 1 are opened. Through the cooperation of the second switch valves, the flow values ​​of the upper and lower strokes are monitored, further improving the inspection accuracy. Alternatively, a buffer tank can be added to the main pipeline to reduce the impact of flow fluctuations on the inspection results. At the same time, the second switch valve should be used to switch and select different standard gauges to adapt to different ranges.

[0031] The implementation principle of this application embodiment is as follows: In implementation, the system controls the main regulating valve 5 to quickly adjust and stabilize the total flow rate of the pipeline at a certain required calibration point flow value, which is then monitored by the standard gauge 1. At this time, the float of the tested rotor flowmeter 3 is stabilized at a certain height, indicating an initial flow value. When the flow rate stabilizes, during the upper stroke measurement, the system uniformly opens the upper stroke flow regulating valve FVH4 connected in parallel to both ends of the tested rotor flowmeter 3. This provides a bypass for the fluid in the tested rotor flowmeter 3, causing the flow rate through the tested rotor flowmeter 3 to decrease slowly, and its float to fall accordingly. After the upper stroke flow regulating valve FVH4 is opened to a certain degree, the system uniformly closes the upper stroke flow regulating valve FVH4. During the closing process, the bypass flow decreases, and the flow rate through the tested rotor flowmeter 3 slowly increases again, causing the float to rise accordingly until the upper stroke flow regulating valve FVH4 is completely closed, and the flow rate through the tested rotor flowmeter 3 returns to the initial stable value. After the flow rate stabilizes, the operator or... The image recognition system records the indicated value or signal value of the scale line of the measured rotor flowmeter 3, which is the upper stroke indication value. During the lower stroke measurement, the system opens the lower stroke flow regulating valve FVL6, which is connected in parallel across the main regulating valve 5, at a constant speed. This provides an additional bypass to the main regulating valve 5, causing a slight change in the flow and pressure of the main flow through the main regulating valve 5 and the measured rotor flowmeter 3. The flow rate through the measured rotor flowmeter 3 increases slowly, and its float rises accordingly. After the lower stroke flow regulating valve FVL6 is opened to a certain degree, the system closes it at a constant speed. During the closing process, the flow rate through the measured rotor flowmeter 3 decreases slowly again, and the float falls accordingly until the lower stroke flow regulating valve FVL6 is completely closed. After the flow stabilizes, the operator or the image recognition system records the indicated value or signal value of the scale line of the measured rotor flowmeter 3, which is the lower stroke indication value. Finally, the hysteresis is calculated using the formula "hysteresis = |upper stroke value - lower stroke value|", which makes the measurement results more accurate and facilitates operation.

[0032] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A standard device for a rotor flowmeter with automatic hysteresis testing function, comprising a standard table (1) for flow reference, characterized in that, The standard meter (1) is connected to a first switching valve (2) via a pipe. The first switching valve (2) is connected to a rotor flow meter (3) via a pipe. The rotor flow meter (3) is connected in parallel to an upper stroke flow regulating valve FVH (4) via a pipe. The rotor flow meter (3) is connected in series to a main regulating valve (5) via a pipe. The main regulating valve (5) is connected in parallel to a lower stroke flow regulating valve FVL (6) via a pipe. The main regulating valve (5) is equipped with a control unit (7) for fast and precise control of the main regulating valve (5). The control unit (7) adopts a PID control algorithm and a fuzzy algorithm.

2. The rotor flowmeter standard device with automatic back differential check function according to claim 1, characterized in that, When the main regulating valve (5) is installed at the inlet position of the rotor flowmeter (3) under test, the first switching valve (2) is located between the standard meter (1) and the rotor flowmeter (3) under test, and the rotor flowmeter (3) under test is located between the first switching valve (2) and the main regulating valve (5).

3. The rotor flowmeter standard with automatic back differential check function according to claim 1, characterized in that, When the main regulating valve (5) is installed at the outlet position of the rotor flowmeter (3) under test, the main regulating valve (5) is installed between the rotor flowmeter (3) under test and the standard meter (1).

4. The rotor flowmeter standard of claim 1 having automatic back differential check function, wherein, The standard meter (1) is set in multiple groups, and the range of each standard meter (1) is different. The multiple groups of standard meters (1) are connected to multiple second switching valves (8) through pipelines, so as to match the upper or lower stroke flow monitoring of different flow ranges by switching the second switching valves (8).

5. The rotor flowmeter standard of claim 1 having automatic back differential check function, wherein, The standard meter (1) uses an electromagnetic flowmeter with an accuracy higher than 0.

3.

6. The rotor flowmeter standard of claim 1 having automatic backlash check functionality, wherein, The main regulating valve (5) is a V-type flow regulating valve with valve position feedback.

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