Correction method for sound velocity detection of ultrasonic flowmeter

Abstract

The invention relates to the technical field of ultrasonic flow measurement, and discloses a correction method for sound velocity detection of an ultrasonic flowmeter, which comprises the following steps of: transmitting a first sound wave and measuring the transmission time of the first sound wave on a propagation path of the first sound wave; transmitting a second sound wave and measuring the transmission time of the second sound wave on the propagation path; obtaining an included angle phi between the flowing direction of pipeline fluid and the flow sound channel; calculating the flow velocity of the pipeline fluid through a national standard calculation formula; the sound velocity of the ultrasonic sensor under the pipeline fluid condition is calculated through an empirical formula; and performing measurement precision evaluation on the ultrasonic sensor. The interference factor of the propagation speed of the ultrasonic waves in the gas by the fluid flow velocity is taken into consideration in the calculation method, the sound velocity detection error of the ultrasonic flowmeter is reduced, and the method has remarkable economic benefits.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ultrasonic flow metering, in particular to a correction method for ultrasonic flow meter sound velocity detection. BACKGROUND

[0002] At present, in accordance with relevant international and national standards, the existing fluid ultrasonic flow meter generally adopts time difference method for flow metering. The basic principle is to measure the transmission time of ultrasonic waves in the positive and negative two directions through two ultrasonic sensors, and then to derive the flow rate of the gas according to the difference between the two times, so as to realize the purpose of metering the gas flow. In addition, although the patent CN108120481B introduces two calculation methods of time difference method and time drift method, it provides more ideas for the metering of ultrasonic flow meter. However, in-depth analysis shows that the existing calculation methods have obvious defects, and the most critical problem is that the influence of fluid flow rate on the sound velocity propagation of ultrasonic sensor is not fully considered. In the actual gas flow environment, the fluid flow rate is not constant, and it will change with the change of many factors. The propagation speed of ultrasonic wave in gas will be disturbed by the fluid flow rate. SUMMARY

[0003] In order to solve the existing problems, the present application aims to provide a correction method for ultrasonic flow meter sound velocity detection, which takes into account the interference factors of the propagation speed of ultrasonic wave in gas caused by the fluid flow rate, uses empirical formula to reduce the sound velocity detection error of ultrasonic flow meter, and further solves the technical problem that the measurement accuracy of ultrasonic flow meter needs to be further improved.

[0004] In order to achieve the above purpose, the present application provides the following technical scheme.

[0005] In the first aspect, the present application provides a correction method for ultrasonic flow meter sound velocity detection, comprising the following steps: emitting a first sound wave and measuring the transmission time of the first sound wave on its propagation route ; emitting a second sound wave and measuring the transmission time of the second sound wave on its propagation route ; obtaining the included angle Φ between the flow direction of the pipeline fluid and the flow sound channel calculating the flow rate of the pipeline fluid by the national standard calculation formula ; calculating the sound velocity of the ultrasonic sensor under the condition of pipeline fluid by empirical formula , wherein the empirical formula is: ; evaluating the measurement accuracy of the ultrasonic sensor.

[0006] As a further improvement of the present invention, the measurement accuracy evaluation of the ultrasonic sensor includes the following steps: The sound velocity of the ultrasonic sensor under pipeline flow conditions The measured sound velocity value is used as the theoretical sound velocity value; the product design sound velocity value of the ultrasonic sensor is obtained as the theoretical sound velocity value. Determine whether the difference between the measured sound speed value and the theoretical sound speed value is less than a preset threshold.

[0007] As a further improvement of the present invention, the preset threshold is two per thousand.

[0008] As a further improvement of the present invention, the fluid in the pipeline is either a gas or a liquid.

[0009] As a further improvement of the present invention, the fluid in the pipeline is a clear and uniform fluid.

[0010] As a further improvement of the present invention, the flow velocity of the fluid in the pipeline does not exceed 30 m / s.

[0011] As a further improvement of the present invention, the pair of ultrasonic sensors constituting the flow channel on the pipe both extend through the pipe wall into the inside of the pipe.

[0012] As a further improvement of the present invention, the diameter of the pipe is less than or equal to 3m.

[0013] In a second aspect, the present invention also discloses a computer-readable storage medium storing instructions that, when executed on an electronic device, cause the electronic device to perform a calibration method for sound velocity detection of an ultrasonic flow meter as described in any one of claims 1-8.

[0014] Thirdly, the present invention also discloses a computer program product containing instructions that, when the computer program product is run on an electronic device, cause the electronic device to perform a calibration method for ultrasonic flowmeter sound velocity detection as described in any one of claims 1-8.

[0015] The present invention has the following beneficial effects: The propagation time is measured along the propagation paths of the first and second sound waves, respectively. and This avoids measurement errors caused by inaccurate propagation paths, providing reliable basic data for subsequent accurate calculation of fluid velocity and sound velocity, and improving the accuracy of sound velocity detection; the sound velocity of the ultrasonic sensor under pipeline flow conditions is calculated using empirical formulas. This method considers the influence of the actual fluid characteristics within the pipeline on the sound velocity. Compared to sound velocity calculations that do not consider fluid conditions, it can more accurately obtain the actual sound velocity of the ultrasonic sensor under the current working environment, providing key parameters for sound velocity detection calibration. Evaluating the measurement accuracy of the ultrasonic sensor helps to promptly identify problems in the sensor measurement process, determine the reliability of the measurement results, and ensure the accuracy and stability of the entire ultrasonic flowmeter sound velocity detection system, providing quality assurance for subsequent applications such as flow metering. Furthermore, this method does not require additional measurement of angle or velocity variables; empirical formulas can be applied to easily measurable parameters in the detection scenario for calculation, making it convenient, fast, and highly accurate. The socio-economic value brought about by the improved detection accuracy is significant. Attached Figure Description

[0016] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely schematic to aid in understanding the invention and are not intended to specifically limit the shapes and proportions of the components. In the drawings: Figure 1 A schematic diagram illustrating the steps of a calibration method for sound velocity detection in an ultrasonic flow meter, provided in an embodiment of this application; Figure 2 A schematic diagram illustrating the application of an ultrasonic flowmeter sound velocity detection correction method provided in this embodiment of the application; Figure 3 A schematic diagram of ultrasonic retrograde motion applied to a correction method for sound velocity detection of an ultrasonic flow meter provided in an embodiment of this application; Among them, 1. First sensor; 2. Second sensor; 3. Pipeline. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0018] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is stated to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0020] Example 1 A pair of ultrasonic sensors are installed on the pipe 3 to be tested. The ultrasonic sensor located upstream of the fluid in the pipe is designated as the first sensor 1, and the ultrasonic sensor located downstream of the fluid in the pipe is designated as the second sensor 2. The distance between the two sensors is L. The first sensor 1 is used to emit a first sound wave, and the second sensor 2 is used to receive the first sound wave. The second sensor 2 is used to emit a second sound wave, and the first sensor 1 is used to receive the second sound wave.

[0021] like Figure 1 As shown, a calibration method for sound velocity detection in an ultrasonic flow meter includes the following steps: The first sound wave is emitted and its propagation time is measured along its path. ; A second sound wave is emitted, and its propagation time is measured along its path. ; Obtain the angle Φ between the flow direction of the fluid in the pipeline and the flow channel; Calculate the flow velocity of fluid in the pipeline using the national standard calculation formula. ; The sound velocity of the ultrasonic sensor under pipeline flow conditions was calculated using empirical formulas. ; The measurement accuracy of the ultrasonic sensor is evaluated.

[0022] Specifically, the sound velocity of the ultrasonic sensor under pipeline flow conditions is calculated using empirical formulas. The empirical formula mentioned therein is: .

[0023] The derivation of the above empirical formula is as follows: like Figure 2 As shown, assume the flow velocity of the fluid in pipe 3 is... The speed of sound is Establish a Cartesian coordinate system along the actual propagation path, with the ultrasonic propagation direction as the X-axis and the perpendicular direction as the Y-axis. The channel length of the actual propagation path is L0, and based on experience, L0 is taken as L. The angle between the flow velocity and the actual ultrasonic propagation path is... The angle between the initial angle of the sound velocity and the actual propagation path is .

[0024] Assuming that during forward motion, the first sensor 1 (ultrasonic sensor A) emits an ultrasonic signal, and the second sensor 2 (ultrasonic sensor B) receives the signal, with a transmission time of... .

[0025] Given the anterograde ultrasound time, the following equation is derived: Formula 1 like Figure 3 As shown, assuming that during reverse movement, the second sensor 2 (ultrasonic sensor B) emits an ultrasonic signal, and the first sensor 1 (ultrasonic sensor A) receives the signal, the transmission time is... Establish a rectangular coordinate system along the actual propagation path, with the ultrasonic propagation direction as the X direction and the perpendicular direction as the Y direction.

[0026] Assuming the flow rate is still at this point The speed of sound is Given the ultrasound retrograde time, the following equation is derived: Formula 2 The derivation process is as follows: Combining Equations 1 and 2, the derivation process is as follows:

[0027]

[0028]

[0029] Conclusion:

[0030]

[0031]

[0032] The angle between the flow velocity and the actual ultrasound Approaching the angle between the ultrasonic sensor and the three axes of the pipe Therefore Practical experience has verified that this approximation method is accurate and reliable, and it eliminates the need for measurement. The required equipment adjustments; therefore, the conclusion is: Consistent with the national standard calculation formula; Speed ​​of sound The calculation formula (empirical formula) is as follows:

[0033] Specifically, the measurement accuracy evaluation of the ultrasonic sensor includes the following steps: The sound velocity of the ultrasonic sensor under pipeline flow conditions The measured sound velocity value is used as the theoretical sound velocity value; the product design sound velocity value of the ultrasonic sensor is obtained as the theoretical sound velocity value. Determine whether the difference between the measured sound speed value and the theoretical sound speed value is less than two-thousandths of the theoretical sound speed value.

[0034] The fluid in the pipeline is either a gas or a liquid. Among the three common states of solid, gas, and liquid, pipeline transportation mainly involves gaseous and liquid substances.

[0035] The fluid in the pipeline is a clear and homogeneous fluid. Generally speaking, impurities and uneven distribution in the fluid can significantly interfere with the propagation of sound waves. Using a clear and homogeneous fluid makes the propagation of sound waves in the fluid more stable and regular, thereby improving the accuracy and reliability of sound velocity detection and reducing measurement errors.

[0036] The flow velocity of the fluid in the pipeline does not exceed 30 m / s. The flow velocity of fluid in most pipelines is below 30 m / s; the conveying velocity of low-pressure gas is typically 8-15 m / s, and that of high-pressure gas is 5-20 m / s; the velocity of low-viscosity liquids is 1.5-3 m / s, and that of high-viscosity liquids is 0.2-1.5 m / s. Therefore, this method is applicable to most gas and liquid pipeline conveying scenarios.

[0037] The pair of ultrasonic sensors forming the flow channel on the pipe 3 both extend through the pipe wall into the interior of the pipe 3. This arrangement brings the sensors closer to the fluid, reducing the attenuation and interference of the pipe wall on the sound waves. This allows for more direct and effective reception and transmission of sound waves, improving the strength and quality of the sound signal, and consequently enhancing the accuracy of sound velocity detection.

[0038] The diameter of pipe 3 is less than or equal to 3m. The diameter of most municipal transportation pipelines is less than 3m, and within this diameter range, the flow state of the fluid inside the pipeline is relatively easier to control and predict, and the propagation characteristics of sound waves inside the pipeline are relatively stable, which is conducive to accurate sound velocity detection and correction.

[0039] According to the verification procedure of JJG1030-2007 "Ultrasonic Flow Meter", the existing sound velocity The calculation method is as follows:

[0040] The table below shows the measured data of the ultrasonic sensor. The measured sound velocity and theoretical sound velocity values ​​are calculated using existing calculation methods and the corrected calculation method in this application, respectively. The ratio of the difference between the two to the theoretical sound velocity value is used for accuracy evaluation. The pipe diameter is taken as 50 mm (the channel length L is 70.7 mm), and the angle Φ between the flow direction of the fluid in the pipe and the flow channel is taken as 45°.

[0041]

[0042] It can be seen that the existing algorithm, under the conditions of flow velocities of 29.74 m / s and 26.03 m / s, yields the measured sound velocity values... The measured sound velocity (calculated based on the actual time difference) does not meet the national standard accuracy of 0.2%, while the measured sound velocity value after correction considering the fluid velocity actually meets the national standard accuracy of 0.2%. Furthermore, it can be seen that the higher the fluid velocity, the higher the percentage deviation (accuracy level of 0.1%) for both the existing and corrected methods. This corroborates that increased fluid velocity has a certain impact on existing ultrasonic transmission; specifically, increased fluid velocity slows down the transmission speed of ultrasound in the sound channel. This aligns with the theoretical analysis that sound waves have a component along the fluid velocity direction, thus reducing the component propagating in the sound channel direction.

[0043] Example 2 This embodiment also discloses a computer-readable storage medium storing instructions that, when executed on an electronic device, cause the electronic device to perform a calibration method for ultrasonic flowmeter sound velocity detection as described in Embodiment 1.

[0044] Example 3 This embodiment also discloses a computer program product containing instructions that, when run on an electronic device, cause the electronic device to perform a calibration method for ultrasonic flowmeter sound velocity detection as described in Embodiment 1.

[0045] The electronic device containing this computer program is electrically connected to a pair of ultrasonic sensors forming a flow channel, enabling real-time measurement of fluid velocity in the pipeline. and speed of sound The former can be applied to pipeline fluid velocity and flow rate monitoring in most scenarios, while the latter can be applied to the flow channel velocity calibration (product measurement accuracy calibration) of ultrasonic flow meter products.

[0046] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative; for example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0047] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0048] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0049] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the term "comprising" or any other variations thereof is intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes said element.

[0050] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A calibration method for sound velocity detection in an ultrasonic flow meter, characterized in that, Includes the following steps: The first sound wave is emitted and its propagation time is measured along its path. ; A second sound wave is emitted, and its propagation time is measured along its path. ; Obtain the angle Φ between the flow direction of the fluid in the pipeline and the flow channel; Calculate the flow velocity of fluid in the pipeline using the national standard calculation formula. ; The sound velocity of the ultrasonic sensor under pipeline flow conditions was calculated using empirical formulas. The empirical formula is as follows: ; The measurement accuracy of the ultrasonic sensor is evaluated.

2. The calibration method for sound velocity detection of an ultrasonic flowmeter according to claim 1, characterized in that, The measurement accuracy evaluation of the ultrasonic sensor includes the following steps: The sound velocity of the ultrasonic sensor under pipeline flow conditions The measured sound velocity value is used as the theoretical sound velocity value; the product design sound velocity value of the ultrasonic sensor is obtained as the theoretical sound velocity value. Determine whether the difference between the measured sound speed value and the theoretical sound speed value is less than a preset threshold.

3. The calibration method for sound velocity detection of an ultrasonic flowmeter according to claim 1, characterized in that, The preset threshold is two per thousand.

4. The calibration method for sound velocity detection of an ultrasonic flowmeter according to claim 1, characterized in that, The fluid in the pipeline is either a gas or a liquid.

5. The calibration method for sound velocity detection of an ultrasonic flowmeter according to claim 1, characterized in that, The fluid in the pipeline is a clear and homogeneous fluid.

6. The calibration method for sound velocity detection of an ultrasonic flowmeter according to claim 1, characterized in that, The flow velocity of the fluid in the pipeline does not exceed 30 m / s.

7. The calibration method for sound velocity detection of an ultrasonic flowmeter according to claim 1, characterized in that, The pair of ultrasonic sensors that form the flow channel on the pipe (3) both extend into the inside of the pipe (3) through the pipe wall.

8. The calibration method for sound velocity detection of an ultrasonic flowmeter according to claim 1, characterized in that, The diameter of the pipe (3) is less than or equal to 3m.

9. A computer-readable storage medium storing instructions, characterized in that, When the instruction is executed on the electronic device, the electronic device performs a calibration method for ultrasonic flowmeter sound velocity detection as described in any one of claims 1-8.

10. A computer program product containing instructions, characterized in that, When the computer program product is run on the electronic device, the electronic device performs a calibration method for ultrasonic flowmeter sound velocity detection as described in any one of claims 1-8.

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