Ultrasonic metering structure, metering method and meter based on reciprocity

Abstract

The invention relates to the technical field of ultrasonic metering, and particularly discloses a reciprocity-based ultrasonic metering structure, metering method and meter, the metering structure comprises a measuring pipe section, a first transducer and a second transducer, the first transducer and the second transducer are used for receiving or transmitting ultrasonic pulses; two ports of the measuring pipe section are respectively communicated through a first pipeline and a second pipeline which are connected in parallel, the first pipeline is provided with an inlet for a metered object to enter the measuring pipe section, and the first pipeline on two sides of the inlet is respectively provided with a first valve body and a second valve body; an outlet is formed in the second pipeline so that a metered object can be discharged from the measuring pipe section, and a third valve body and a fourth valve body are arranged on the portions, on the two sides of the outlet, of the second pipeline respectively. According to the metering method, the metering structure is adopted. The ultrasonic wave meter adopts the ultrasonic wave metering method based on reciprocity. The structure is reasonable, the design is ingenious, the measurement precision is greatly improved, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic metrology technology, specifically to an ultrasonic metrology structure, metrology method, and metrology meter based on reciprocity. Background Technology

[0002] Ultrasonic meters, such as ultrasonic water meters and gas meters, offer advantages such as high measurement accuracy, good reliability, and low pressure loss. However, during their application, due to the influence of transducer performance, pipe section processing precision, and metering circuitry, even when the medium is still and the minute flow caused by molecular thermal motion is negligible, the ultrasonic pulses emitted by the same pair of transducers still exhibit a certain time difference in the forward and reverse directions, resulting in zero-point drift and thus affecting measurement accuracy. Furthermore, because the speed of ultrasonic pulses in the medium varies at different temperatures, the up-and-down time difference obtained when the temperature changes often deviates, resulting in temperature drift. Additionally, the zero-point drift and temperature drift characteristics of different ultrasonic meters within the same batch are not entirely consistent. Therefore, even with metering compensation applied to an ultrasonic meter of a specific specification, it is difficult to accommodate the differences in zero-point drift or temperature drift characteristics between meters from different batches.

[0003] Furthermore, in production practice, a certain proportion of air bubbles are often mixed in the pipeline. When ultrasonic waves pass through the reflective surfaces of liquids and gases, reflection occurs, causing the received amplitude of the sound wave to decrease and the received waveform to be distorted. Under the condition of decreased ultrasonic received amplitude and distorted received waveform, ultrasonic metering often experiences zero drift or even wave jumping, causing the measured value of the ultrasonic water meter to deviate from the actual value, resulting in water meter reading errors or even incorrect readings.

[0004] Existing technologies typically address zero-point drift through zero-flow calibration during the factory manufacturing process, and temperature drift is usually compensated for by measuring the impact of temperature on measurement accuracy. However, zero-flow calibration of ultrasonic water meters increases the workload of calibration personnel during actual production, leading to increased production and labor costs. Furthermore, the cumbersome calibration process is detrimental to improving production efficiency.

[0005] As is well known, "reciprocity" is a core physical principle in ultrasonic meters. It ensures that when an ultrasonic signal propagates in a fluid in both upstream and downstream directions, the propagation time difference is determined only by the fluid velocity and is unaffected by changes in the speed of sound itself. Existing technologies for reciprocity design in ultrasonic meters often utilize matching circuits to compensate for changes in the physical characteristics of the transducer and design relevant filter circuits to achieve reciprocity between ultrasonic signal excitation and reception. However, such methods generally only achieve partial reciprocity of the circuit. When used to solve zero-point drift or temperature drift problems, they can reduce the errors caused by drift, as shown in the patent document with application number CN201710036416.2 entitled "A Circuit Design Method for Eliminating Zero-Point Drift in a Gas Ultrasonic Flow Meter".

[0006] In production practice, ultrasonic meters inevitably experience aging and contamination of the transducer during use. At this time, the physical characteristics of the transducer deviate significantly from their initial physical characteristics. Even if the calibration or compensation is performed at the factory, a secondary calibration is still required. Using only the matching circuit method often leads to a large degree of measurement error, which is not conducive to improving measurement accuracy. Summary of the Invention

[0007] This invention discloses an ultrasonic metrology structure, method, and meter based on reciprocity. It solves the technical problems of low measurement accuracy caused by zero-point drift or temperature drift in existing technologies, and the time-consuming and labor-intensive calibration and supplementation processes that hinder production efficiency. It features a reasonable structure, ingenious design, significantly improved measurement accuracy, and reduced production costs. The technical solution adopted is as follows: An ultrasonic metering structure based on reciprocity includes a measuring tube section, a first transducer, and a second transducer, wherein the first transducer and the second transducer are used to receive or transmit ultrasonic pulses. The two ends of the measuring pipe section are connected by a first pipe and a second pipe in parallel. The first pipe is provided with an inlet for the measuring object to enter the measuring pipe section. A first valve body and a second valve body are respectively provided on the first pipe on both sides of the inlet. The second pipe is provided with an outlet for the measuring object to be discharged from the measuring pipe section. A third valve body and a fourth valve body are respectively provided on the second pipe on both sides of the outlet.

[0008] Based on the above technical solution, a controller is also included. The first valve body, the second valve body, the third valve body and the fourth valve body are electrically connected to the controller. The first valve body and the third valve body are linked and designed to allow the metering object to flow from the first transducer to the second transducer. The second valve body and the fourth valve body are linked and designed to allow the metering object to flow from the second transducer to the first transducer.

[0009] Based on the above technical solution, the first transducer and the second transducer are arranged symmetrically.

[0010] Based on the above technical solution, it also includes a first storage area, a second storage area, and a third storage area; the first storage area is designed to store the flow information of the metered object when it flows from the first transducer to the second transducer; the second storage area is designed to store the flow information of the metered object when it flows from the second transducer to the first transducer; and the third storage area is designed to store the flow information stored in the first storage area and the flow information stored in the second storage area after metering.

[0011] An ultrasonic metrology method based on reciprocity, employing the metrology structure described above, includes the following steps: S1. Construct a downstream model and measure the first instantaneous flow rate. Call the first instantaneous flow rate and obtain the cumulative flow rate Q1 of the metering object flowing from the first transducer to the second transducer within a set time T1. The construction of the downstream model includes the following steps: S11. Prepare multiple ultrasonic meters of the same specifications. S12. On a calibrated metering stand, under normal temperature conditions, multiple ultrasonic meters of the same specification are used. The object being measured flows from the first transducer to the second transducer. The flow coefficient is obtained as a function of the flow rate in the measuring pipe section. ; Calling functions Measuring the first instantaneous flow rate: ; K1 is the flow coefficient in the downstream model, which is the proportionality coefficient for converting the linear velocity in the measuring pipe section into the surface velocity in the downstream model. D is the inner diameter of the measuring pipe section; C0 represents the speed of sound of an ultrasonic pulse. The time difference between the up and down of the ultrasonic pulse when the object being measured flows from the first transducer to the second transducer; L is the effective sound path of the ultrasonic pulse within the measuring pipe section; S2. Switch the object being measured in the ultrasonic meter to flow from the second transducer to the first transducer, construct a counter-flow model and measure the second instantaneous flow rate, and obtain the cumulative flow rate Q2 of the object being measured from the second transducer to the first transducer within a set time T2. The construction of the reverse flow model includes the following steps: S21. Prepare multiple ultrasonic meters of the same specifications. S22. On a calibrated calibration stand, using multiple ultrasonic meters of the same specification, the object being measured flows from the second transducer to the first transducer, and the flow coefficient is obtained as a function of the flow rate within the measuring pipe section. ; Calling functions Measuring the second instantaneous flow rate: ; K2 is the flow coefficient in the counter-flow model, which is the proportionality coefficient for converting the linear velocity in the measuring pipe section into the surface velocity in the counter-flow model. D is the inner diameter of the measuring pipe section; C0 represents the speed of sound of an ultrasonic pulse. The time difference between the up and down of the ultrasonic pulse when the object being measured flows from the second transducer to the first transducer; L is the effective sound path of the ultrasonic pulse within the measuring pipe section; S3. Call the accumulated traffic Q1 within the set time T1, call the accumulated traffic Q2 within the set time T2, obtain the accumulated traffic Q1+Q2 within time T1+T2, and store the accumulated traffic Q1+Q2 as the accumulated traffic Q31 within the set time T1+T2.

[0012] Based on the above technical solution, after the cumulative traffic Q31 is stored, T1, Q1, T2 and Q2 are cleared, and steps S1, S2 and S3 are repeated to obtain the cumulative traffic Q32 and store it.

[0013] Based on the above technical solution, during the process of constructing a downstream model and measuring the first instantaneous flow rate, the function of obtaining the flow coefficient with respect to the flow rate within the measurement pipe section is described. At the same time, multiple continuous and different flow points are set, and the number of measurements for each flow point is no less than 3; during the process of constructing the reverse flow model and measuring the second instantaneous flow, the function of the flow coefficient with respect to the flow in the measurement pipe section is obtained. At the same time, multiple consecutive and different flow points are set, and the number of measurements for each flow point is not less than 3.

[0014] Based on the above technical solution, the least squares method is used to fit and obtain the linear function. and linear functions .

[0015] Based on the above technical solution, the flow range of the ultrasonic meter is divided into multiple flow segments. For each flow segment, a piecewise function of the flow coefficient with respect to the flow rate within the measuring pipe segment is obtained. or piecewise function .

[0016] Based on the above technical solution, the time interval between switching between the downstream model and the upstream model is not less than 10 minutes.

[0017] Based on the above technical solution, T1 = T2.

[0018] An ultrasonic meter, employing the reciprocity-based ultrasonic measurement method described above, includes: The metering structure includes a measuring tube section, a first transducer, and a second transducer. The first and second transducers are used to receive or transmit ultrasonic pulses. The two ports of the measuring tube section are connected by a first pipe and a second pipe in parallel. The first pipe has an inlet for the metered object to enter the measuring tube section, and a first valve body and a second valve body are respectively provided on the first pipe on both sides of the inlet. The second pipe has an outlet for the metered object to exit from the measuring tube section, and a third valve body and a fourth valve body are respectively provided on the second pipe on both sides of the outlet. Storage unit, used to store the flow coefficient as a function of the flow rate within the measurement pipe section in the downstream model. In the counter-flow model, the flow coefficient is a function of the flow rate within the measurement pipe section. ; The acquisition unit acquires the uplink and downlink time difference of the ultrasonic pulse in the downstream model. The time difference between the uplink and downlink of ultrasonic pulses in the countercurrent model ; The metering unit is used to measure the first instantaneous flow rate in the downstream model and the second instantaneous flow rate in the upstream model.

[0019] Beneficial effects In this invention, the ultrasonic metering structure connects the two ends of the measuring pipe section via parallel first and second pipes. By controlling the on / off state of the four valves, the flow of the metered object from the first transducer to the second transducer, or from the second transducer to the first transducer, can be controlled. This provides the conditions for implementing either a downstream or upstream flow model. Furthermore, corresponding first, second, and third storage areas are configured to store the relevant flow information.

[0020] In the ultrasonic measurement method of this invention, a two-way model is constructed, namely a co-current model and a counter-current model. In the co-current model, the corresponding flow coefficient is obtained as a function of the flow rate in the measurement pipe section. This allows us to obtain the first instantaneous flow rate and the cumulative flow rate Q1; in the counter-flow model, we obtain the corresponding flow direction coefficient as a function of the flow rate within the measurement pipe section. The second instantaneous flow rate and cumulative flow rate Q2 are then obtained. The cumulative flow rate Q1 obtained from the downstream model and the cumulative flow rate Q2 obtained from the upstream model are then added together to form the cumulative flow rate Q31 within the time period T1+T2 and stored. The metering method in this invention is ingeniously designed. It not only overcomes zero-point drift caused by transducer performance, measurement pipe section processing accuracy, and metering circuitry, and overcomes temperature drift caused by temperature changes, but also avoids the tedious zero-point drift calibration or temperature drift compensation work before the meter leaves the factory, thus improving production efficiency and reducing labor costs. Furthermore, the metering method involved in this invention effectively solves the problem of reduced measurement accuracy caused by zero-point drift or temperature drift due to meter aging and contamination through the construction of a bidirectional model. It also helps to extend the service life of the meter and reduce user operating costs.

[0021] The ultrasonic measurement method in this invention is simple, easy to implement, and reliable in operation, and obtains the function. and functions For each flow point, the flow coefficient is measured no less than three times. This ensures that the function of the flow coefficient with respect to the flow rate within the measurement pipe segment more accurately reflects the relationship between the flow coefficient and the flow rate within the measurement pipe segment. Furthermore, based on multiple flow segments, for each flow segment, a piecewise function of the flow coefficient with respect to the flow rate within the measurement pipe segment is obtained. This further ensures that the function accurately reflects the relationship between the flow coefficient and the flow rate within the measurement pipe segment, which is beneficial for more precise compensation of drift and for improving measurement accuracy.

[0022] In this invention, the time interval between switching between the downstream model and the upstream model is not less than 10 minutes, which can effectively reduce the measurement error caused by model switching and help to further improve the measurement accuracy.

[0023] The ultrasonic meter disclosed in this invention, based on a reciprocity design, effectively solves the zero-point drift and temperature drift problems inherent in ultrasonic meters. This not only reduces the workload of calibration or supplementation by personnel before delivery, thus lowering labor costs and improving production efficiency, but also allows for secondary correction in the event of aging or contamination during use. This is achieved by updating the flow coefficients in the co-current and counter-current models as a function of the flow rate within the measuring pipe section, further extending the lifespan of the ultrasonic meter and reducing operating costs. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For those skilled in the art, other embodiments can be derived from the provided drawings without creative effort.

[0025] Figure 1 : Schematic diagram of the ultrasonic water meter measuring pipe section in this application; Figure 2 : Schematic diagram of the metering structure in this invention; Figure 3 : A schematic diagram of the measurement method in this invention; Reference numerals in the attached drawings: 1-First transducer; 2-Second transducer; 3-Measuring pipe section; 10-First valve body; 20-Second valve body; 30-Third valve body; 40-Fourth valve body. Detailed Implementation

[0026] In this document, unless otherwise stated, the term "multiple" means two or more.

[0027] In this article, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0028] In this article, the term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0029] Taking an ultrasonic water meter as an example, the structure of an ultrasonic water meter consists of a measuring pipe section 3, a transducer group, and a metering circuit. During the metering process, the ultrasonic water meter uses the time difference to measure the instantaneous flow rate. The principle is shown below: In existing technology, the water flow within the measuring pipe section 3 of an ultrasonic water meter is directional, so as to... Figure 1 As shown in the example, the propagation time of the ultrasonic pulse going backwards is... T UP It can be calculated as follows: (1) downstream propagation time T DOWN It can be calculated as follows: (2) because The formula for calculating the uplink and downlink propagation time difference of ultrasound can be simplified to: (3); According to equation (3), if the ultrasonic water meter is installed in a closed, still water environment, v is zero, and the theoretical time difference is... It should be 0.

[0030] However, due to the inconsistency between the equivalent circuits of the transducer's transmitting and receiving signals, the actual time difference data obtained by the ultrasonic water meter is not zero, and there is a certain zero drift error.

[0031] because The above equation (3) can be transformed to obtain (4); That is, the streamline velocity of water in the measuring pipe section 3 is obtained by equation (4). In practice, it needs to be converted into the surface velocity of the measuring pipe section 3 according to a certain proportional coefficient K. That is, K is the proportional coefficient for converting the streamline velocity into the surface velocity, which is called the flow coefficient in this application. Then, the instantaneous flow rate of the measuring pipe section 3 is obtained as follows: (5); C0 is the current propagation speed of the ultrasonic pulse in water; v is the streamline velocity of the water in measuring pipe section 3; The cumulative time value includes circuit delay, transducer start-up delay, and ultrasonic timing delay; To measure the instantaneous volumetric flow rate of water in pipe section 3; D is the inner diameter of section 3 of the ultrasonic water meter measuring pipe; This refers to the time difference between the upward and downward propagation of ultrasonic waves. K is the flow meter coefficient, which is defaulted to 1 in existing technology; This application discloses an ultrasonic metrology structure based on reciprocity, comprising a measuring tube section 3, a first transducer 1, and a second transducer 2, wherein the first transducer 1 and the second transducer 2 are used to receive or transmit ultrasonic pulses; as Figure 1 As shown, the first transducer 1 and the second transducer 2 are arranged symmetrically, that is, the first transducer 1 and the second transducer 2 are installed on the upstream and downstream sides of the measuring pipe section 3 in a geometrically symmetrical manner, so that the first transducer 1 and the second transducer 2 are installed relative to each other at a certain angle (such as Z method, V method or W method), so that the ultrasonic pulse can propagate along a symmetrical path in the measuring object.

[0032] The two ends of the measuring pipe section 3 are connected by a first pipe and a second pipe in parallel. The first pipe is provided with an inlet for the measuring object to enter the measuring pipe section 3. The first pipe on both sides of the inlet is provided with a first valve body 10 and a second valve body 20 respectively. The second pipeline is provided with an outlet for the metering object to be discharged from the measuring pipe section 3. The second pipeline on both sides of the outlet is provided with a third valve body 30 and a fourth valve body 40 respectively.

[0033] It also includes a controller, and the first valve body 10, the second valve body 20, the third valve body 30 and the fourth valve body 40 are electrically connected to the controller. The first valve body 10 and the third valve body 30 are linked and designed to allow the metered object to flow from the first transducer 1 to the second transducer 2; the second valve body 20 and the fourth valve body 40 are linked and designed to allow the metered object to flow from the second transducer 2 to the first transducer 1.

[0034] In this embodiment, the controller includes a microcontroller. The first valve body 10, the second valve body 20, the third valve body 30, and the fourth valve body 40 are all electric valve bodies. The first valve body 10 and the third valve body 30 are controlled by a first double-pole double-throw analog switch, and the second valve body 20 and the fourth valve body 40 are controlled by a second double-pole double-throw analog switch. The double-pole double-throw analog switch can be a high-speed, low-power double-pole double-throw analog switch of model MSUSB30 / MSUSB30N manufactured by Ruimeng Technology. Its operating voltage range is +1.8V to +5.5V, and it has the characteristics of low inter-symbol offset, high channel noise isolation, and wide bandwidth.

[0035] As an example, during operation, after the first double-pole double-throw analog switch controls the first valve body 10 and the third valve body 30 to open to the correct position, the operating current of the first double-pole double-throw analog switch is cut off. Simultaneously, after the second double-pole double-throw analog switch controls the second valve body 20 and the fourth valve body 40 to the closed state, the operating current of the second double-pole double-throw analog switch is cut off. This allows the metered object to flow from the first transducer 1 to the second transducer 2, resulting in high reliability and a low failure rate. When it is necessary to control the flow of the metered object from the second transducer 2 to the first transducer 1, the reverse is true.

[0036] In the prior art, ultrasonic meters measure objects with fixed flow directions, and correspondingly, they often only store and measure flow information for a set flow rate. The metering structure in this invention also includes a first storage area, a second storage area, and a third storage area. The first storage area is designed to store flow information of the metered object flowing from the first transducer 1 to the second transducer 2; the second storage area is designed to store flow information of the metered object flowing from the second transducer 2 to the first transducer 1; the third storage area is designed to store the flow information stored in the first storage area and the flow information stored in the second storage area after metering, so as to adapt to the metering structure in the present invention.

[0037] An ultrasonic metrology method based on reciprocity, employing the metrology structure described above, includes the following steps: S1. Construct a downstream model and measure the first instantaneous flow rate, call the first instantaneous flow rate and obtain the cumulative flow rate Q1 of the metering object flowing from the first transducer 1 to the second transducer 2 within a set time T1; The construction of the downstream model includes the following steps: S11. Prepare three ultrasonic meters of the same specifications; in other embodiments of the present invention, one, two or more may be prepared.

[0038] S12. On the calibrated calibration stand, under normal temperature conditions, the measured object flows from the first transducer 1 to the second transducer 2 in three ultrasonic meters of the same specification. That is, the downstream flow model is constructed, and the flow coefficient is obtained as a function of the flow rate in the measuring pipe section 3. In this embodiment, a downstream model is constructed and the flow coefficient is obtained as a function of the flow rate within the measurement pipe segment 3. The process can be completed before leaving the factory, and the function will be... It is stored in the meter; the function can be called when it is actually used.

[0039] Specifically, for each ultrasonic meter, eight or more consecutive and different flow points are set, such as Q11, Q12, Q13, Q14, Q15, Q16, Q17, and Q18. Each flow point is measured at least three times, meaning each meter measures each flow point once, and then the average of the three meters is taken. The flow coefficient is the proportionality coefficient used to convert the linear flow velocity within the measuring pipe segment 3 in the downstream flow model to the surface flow velocity. Specifically, it reflects the ratio of the ultrasonic meter flow rate value to the standard flow rate on the calibration bench. Multiple sets of data are obtained in this way (K11, Q12, Q13, Q14, Q15, Q16, Q17, Q18). 表11 (K12,Q) 表12 (K13,Q) 表13 ... (K1n, Q) 表1n The flow rate value of the ultrasonic meter is calculated using the formula (5) as described above, where K=1.

[0040] Then, by calling the aforementioned sets of data, a linear function is obtained using the least squares method. In other embodiments of the present invention, the flow range of the ultrasonic meter is further divided into two flow segments, and for each flow segment, a piecewise function of the flow coefficient with respect to the flow rate within the measuring pipe segment 3 is obtained. That is, to obtain the piecewise function for the flow segments formed by Q11, Q12, Q13, and Q14. Another piecewise function is obtained for the flow segments formed by Q15, Q16, Q17, and Q18. This allows for a more accurate reflection of the actual instantaneous value.

[0041] Calling functions Measuring the first instantaneous flow rate: ; Specifically, firstly, the measured flow rate Q1 of the ultrasonic meter is read according to equation (5), where K=1; then the function is called. The K1 value was calculated, and then the first instantaneous flow rate was measured. .

[0042] K1 is the flow coefficient in the downstream model, that is, the proportionality coefficient for converting the linear flow velocity in the measurement pipe section 3 into the surface flow velocity in the downstream model; D is the inner diameter of the measuring pipe section 3; C0 represents the speed of sound of an ultrasonic pulse. The time difference between the up and down of the ultrasonic pulse when the object being measured flows from the first transducer 1 to the second transducer 2; L represents the effective acoustic path of the ultrasonic pulse within the measurement pipe section 3 in the downstream model; S2. Through the controller, in the aforementioned metering structure, the metering object in the ultrasonic metering meter is switched to flow from the second transducer 2 to the first transducer 1, a counterflow model is constructed and the second instantaneous flow rate is measured, and the cumulative flow rate Q2 of the metering object flowing from the second transducer 2 to the first transducer 1 within a set time T2 is obtained. The construction of the reverse flow model includes the following steps: S21. Prepare three ultrasonic meters of the same specifications; in other embodiments of the present invention, one, two or more may be prepared.

[0043] S22. On the calibrated meter stand, under normal temperature conditions, in three ultrasonic meters of the same specification, the measured object flows from the second transducer to the first transducer 1, that is, a counter-flow model is constructed, and the flow coefficient is obtained as a function of the flow rate in the measuring pipe section 3. In this embodiment, similarly, a counter-flow model is constructed and the flow coefficient is obtained as a function of the flow rate within the measurement pipe segment 3. The process can be completed before leaving the factory, after which the function will be... It is stored in the meter, and the function can be called during the actual measurement process.

[0044] Specifically, for each ultrasonic meter, eight or more continuous and different flow points are set, such as Q21, Q22, Q23, Q24, Q25, Q26, Q27, and Q28. Each flow point is measured at least three times, meaning each meter measures each flow point once, and then the average value of the three meters is taken. The flow coefficient is the proportionality coefficient used to convert the linear flow velocity within the measuring pipe segment 3 in the downstream flow model to the surface flow velocity. Specifically, it reflects the ratio of the ultrasonic meter flow rate value to the standard flow rate on the calibration bench. Multiple sets of data are obtained in this way (K21, Q...). 表21 (K22,Q) 表22 (K23,Q) 表23 ... (K2n, Q) 表2n ).

[0045] The flow rate value read from the ultrasonic meter is calculated using the formula (5) mentioned above, where K=1.

[0046] Then, by calling the aforementioned sets of data, a linear function is obtained using the least squares method. In other embodiments of the present invention, the flow range of the ultrasonic meter is further divided into two flow segments, and for each flow segment, a piecewise function of the flow coefficient with respect to the flow rate within the measuring pipe segment 3 is obtained. That is, to obtain the piecewise function for the flow segments formed by Q21, Q22, Q23, and Q24. Another piecewise function is obtained for the flow segments formed by Q25, Q26, Q27, and Q28. This allows for a more accurate reflection of the actual instantaneous value.

[0047] Calling functions Measuring the second instantaneous flow rate: ; Specifically, first, the measured flow rate Q2 of the ultrasonic meter is read according to equation (5), where K=1; then the function is called. The K2 value was calculated, and then the second instantaneous flow rate was measured. .

[0048] K2 is the flow coefficient in the counter-flow model, which is the proportionality coefficient for converting the linear flow velocity in the measuring pipe section 3 into the surface flow velocity in the counter-flow model. D is the inner diameter of the measuring pipe section 3; C0 represents the speed of sound of an ultrasonic pulse. The time difference between the up and down of the ultrasonic pulse when the object being measured flows from the second transducer 2 to the first transducer 1; L represents the effective acoustic path of the ultrasonic pulse within the measuring pipe section 3 in the counter-current model; In this invention, the time interval between switching between the downstream model and the upstream model is not less than 10 minutes, which can effectively reduce the measurement error caused by model switching and help to further improve the measurement accuracy.

[0049] S3. Call the accumulated traffic Q1 within the set time T1, call the accumulated traffic Q2 within the set time T2, obtain the accumulated traffic Q1+Q2 within time T1+T2, and store the accumulated traffic Q1+Q2 as the accumulated traffic Q31 within the set time T1+T2. In this embodiment, T1=T2.

[0050] Furthermore, after storing the cumulative flow Q31, T1, Q1, T2 and Q2 are cleared. Steps S1, S2 and S3 are repeated to obtain the cumulative flow Q32 and store it. Multiple cumulative flows Q33, Q34...Q3n can be obtained repeatedly, and the average value is taken as the output cumulative flow for staff to read.

[0051] Meters using the above measurement methods can effectively improve measurement accuracy when tested in both static and constant flow environments.

[0052] First, a still water environment was selected. The metering instrument using the above-described measurement method and a standard metering instrument measuring the same pipe section were installed together on the calibration table. The metering instrument using the above-described method switched between the downstream and upstream models every 10 minutes. With the starting flow rate set at 0.5 liters / hour, after measurement, the metering instrument using the above-described method recorded a cumulative flow rate of less than 0.1 liters in half an hour, while the standard metering instrument of the same specifications, under the same starting flow rate, measured a cumulative flow rate of 10 liters in half an hour. This demonstrates that the metering instrument using the above-described method can effectively reduce the starting flow, significantly improving measurement accuracy.

[0053] A constant flow environment was then selected, and the metering instrument using the above measurement method and a regular metering instrument for the same specification measuring pipe section were installed together on the calibration table. The metering instrument using the above measurement method switched between the concurrent flow model and the counter-flow model every 10 minutes. A flow rate point Q was set on the calibration table. 恒2 and Q 恒3 Comparing the error between the cumulative flow rate and the standard flow rate of the meter within half an hour, the meter using the above metering method maintained an error of less than 1%, while the error of ordinary meters exceeded 2%.

[0054] In other embodiments of the present invention, when the ultrasonic meter has been used for a set time, considering the inevitable aging or contamination, the flow coefficient as a function of the flow rate in the measuring pipe section 3 can be updated. and The data is stored in the ultrasonic meter, a clever design that allows for secondary calibration, which helps extend the lifespan of the ultrasonic meter and reduce operating costs.

[0055] An ultrasonic meter, employing the reciprocity-based ultrasonic measurement method described above, includes: The metering structure includes a measuring tube section 3, a first transducer 1, and a second transducer 2. The first transducer 1 and the second transducer 2 are used to receive or transmit ultrasonic pulses. The two ports of the measuring tube section 3 are connected by a first pipeline and a second pipeline in parallel. The first pipeline is provided with an inlet for the metered object to enter the measuring tube section 3. A first valve body 10 and a second valve body 20 are respectively provided on the first pipeline on both sides of the inlet. The second pipeline is provided with an outlet for the metered object to exit from the measuring tube section 3. A third valve body 30 and a fourth valve body 40 are respectively provided on the second pipeline on both sides of the outlet. The storage unit is used to store the flow coefficient as a function of the flow rate within the measurement pipe segment 3 in the downstream model. In the counter-flow model, the flow coefficient is a function of the flow rate within the measuring pipe section 3. ; The acquisition unit acquires the uplink and downlink time difference of the ultrasonic pulse in the downstream model. The time difference between the uplink and downlink of ultrasonic pulses in the countercurrent model ; The metering unit is used to measure the first instantaneous flow rate in the downstream model and the second instantaneous flow rate in the upstream model.

[0056] The present invention has been described above by way of example, but the present invention is not limited to the specific embodiments described above. Any modifications or variations made based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. An ultrasonic metering structure based on reciprocity, characterized in that, It includes a measuring tube section (3), a first transducer (1) and a second transducer (2), the first transducer (1) and the second transducer (2) being used to receive or transmit ultrasonic pulses; The two ends of the measuring pipe section (3) are connected by a first pipe and a second pipe in parallel. The first pipe is provided with an inlet for the measuring object to enter the measuring pipe section (3). The first pipe on both sides of the inlet is provided with a first valve body (10) and a second valve body (20). The second pipe is provided with an outlet for the measuring object to be discharged from the measuring pipe section (3). The second pipe on both sides of the outlet is provided with a third valve body (30) and a fourth valve body (40).

2. The ultrasonic metering structure based on reciprocity according to claim 1, characterized in that, It also includes a controller, wherein the first valve body (10), the second valve body (20), the third valve body (30) and the fourth valve body (40) are electrically connected to the controller, and the first valve body (10) and the third valve body (30) are linked and designed to allow the metering object to flow from the first transducer (1) to the second transducer (2); the second valve body (20) and the fourth valve body (40) are linked and designed to allow the metering object to flow from the second transducer (2) to the first transducer (1).

3. The ultrasonic metering structure based on reciprocity according to claim 1, characterized in that, The first transducer (1) and the second transducer (2) are arranged symmetrically.

4. The ultrasonic metering structure based on reciprocity according to claim 1, characterized in that, It also includes a first storage area, a second storage area and a third storage area; the first storage area is designed to store flow information when the metered object flows from the first transducer (1) to the second transducer (2); the second storage area is designed to store flow information when the metered object flows from the second transducer (2) to the first transducer (1); the third storage area is designed to store the flow information stored in the first storage area and the flow information stored in the second storage area after metering.

5. An ultrasonic measurement method based on reciprocity, characterized in that, The method employs the metering structure described in any one of claims 1 to 4, comprising the following steps: S1. Construct a downstream model and measure the first instantaneous flow rate. Call the first instantaneous flow rate and obtain the cumulative flow rate Q1 of the metering object flowing from the first transducer to the second transducer within a set time T1. The construction of the downstream model includes the following steps: S11. Prepare multiple ultrasonic meters of the same specifications. S12. On the calibrated calibration stand, in multiple ultrasonic meters of the same specification, the measuring object flows from the first transducer (1) to the second transducer (2), and the flow coefficient is obtained as a function of the flow rate in the measuring pipe section (3). ; Calling functions Measuring the first instantaneous flow rate: ； K1 is the flow coefficient in the downstream model, that is, the proportional coefficient for converting the linear flow velocity into the surface flow velocity in the measuring pipe section (3) in the downstream model; D is the inner diameter of the measuring pipe section (3); C0 represents the speed of sound of an ultrasonic pulse. The time difference between the up and down of the ultrasonic pulse when the object being measured flows from the first transducer (1) to the second transducer (2); L is the effective sound path of the ultrasonic pulse in the measuring pipe section (3) in the downstream model; S2. Switch the object being measured in the ultrasonic meter to flow from the second transducer (2) to the first transducer (1), construct a counter-flow model and measure the second instantaneous flow rate, and obtain the cumulative flow rate Q2 of the object being measured flowing from the second transducer (2) to the first transducer (1) within a set time T2. The construction of the reverse flow model includes the following steps: S21. Prepare multiple ultrasonic meters of the same specifications. S22. On the calibrated calibration stand, in multiple ultrasonic meters of the same specification, the measuring object flows from the second transducer (2) to the first transducer (1), and the flow coefficient is obtained as a function of the flow rate in the measuring pipe section (1). ; Calling functions Measuring the second instantaneous flow rate: ； K2 is the flow coefficient in the counter-flow model, that is, the proportional coefficient for converting the linear flow velocity in the measuring pipe section (3) into the surface flow velocity in the counter-flow model; D is the inner diameter of the measuring pipe section; C0 represents the speed of sound of an ultrasonic pulse. The time difference between the up and down of the ultrasonic pulse when the object being measured flows from the second transducer (2) to the first transducer (1); L is the effective sound path of the ultrasonic pulse in the measuring pipe section (3) in the counterflow model; S3. Call the accumulated traffic Q1 within the set time T1, call the accumulated traffic Q2 within the set time T2, obtain the accumulated traffic Q1+Q2 within time T1+T2, and store the accumulated traffic Q1+Q2 as the accumulated traffic Q31 within the set time T1+T2.

6. The ultrasonic measurement method based on reciprocity according to claim 5, characterized in that, After the cumulative flow Q31 is stored, T1, Q1, T2 and Q2 are cleared. Steps S1, S2 and S3 are repeated to obtain the cumulative flow Q32 and store it.

7. The ultrasonic measurement method based on reciprocity according to claim 5, characterized in that, During the process of constructing the downstream model and measuring the first instantaneous flow rate, the function of obtaining the flow coefficient with respect to the flow rate in the measuring pipe section (3) is used. At the same time, multiple continuous and different flow points are set, and the number of measurements for each flow point is not less than 3; during the process of constructing the counterflow model and measuring the second instantaneous flow, the flow coefficient is obtained as a function of the flow in the measuring pipe section (3). At the same time, multiple consecutive and different flow points are set, and the number of measurements for each flow point is not less than 3.

8. The ultrasonic measurement method based on reciprocity according to claim 6, characterized in that, The least squares method is used to fit and obtain the linear function. and linear functions .

9. The ultrasonic metrology method based on reciprocity according to claim 6 or 7, characterized in that, The flow range of the ultrasonic meter is divided into multiple flow segments. For each flow segment, a piecewise function of the flow coefficient with respect to the flow rate within the measuring pipe segment (3) is obtained. or piecewise function .

10. The ultrasonic measurement method based on reciprocity according to any one of claims 5 to 7, characterized in that, The time interval between switching between the downstream model and the upstream model is not less than 10 minutes.

11. The ultrasonic measurement method based on reciprocity according to claim 9, characterized in that, T1 = T2.

12. An ultrasonic meter, employing the reciprocity-based ultrasonic metering method as described in any one of claims 5-7 and 9, comprising: The metering structure includes a measuring tube section (3), a first transducer (1), and a second transducer (2). The first transducer (1) and the second transducer (2) are used to receive or transmit ultrasonic pulses. The two ports of the measuring tube section (3) are connected by a first pipeline and a second pipeline in parallel. The first pipeline is provided with an inlet for the metered object to enter the measuring tube section (3). The first pipeline on both sides of the inlet is provided with a first valve body (10) and a second valve body (20). The second pipeline is provided with an outlet for the metered object to be discharged from the measuring tube section (3). The second pipeline on both sides of the outlet is provided with a third valve body (30) and a fourth valve body (40). Storage unit, used to store the flow coefficient as a function of the flow rate in the measurement pipe section (3) during the downstream model. In the counter-flow model, the flow coefficient is a function of the flow rate within the measuring pipe section (3). ； The acquisition unit acquires the uplink and downlink time difference of the ultrasonic pulse in the downstream model. The time difference between the uplink and downlink of ultrasonic pulses in the countercurrent model ; The metering unit is used to measure the first instantaneous flow rate in the downstream model and the second instantaneous flow rate in the upstream model.

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