Non-contact measurement method and device for pressure of medium in pipeline based on ultrasonic surface wave

Abstract

The application provides a kind of pipeline medium pressure non-contact measurement method and device based on ultrasonic surface wave, the method is by fixing ultrasonic surface wave transceiver module TRA and ultrasonic surface wave transceiver module TRB on the pipeline to be detected, parallel to the central axis of the pipeline to be measured;Start the measurement program of industrial computer, and set the measurement threshold;Get the ultrasonic surface wave propagation time t0 in zero pressure state;The pressure value P of real-time pipeline medium is calculated by the pressure calculation formula based on thickness correction index, and the final pressure value is obtained after averaging;The application can realize high-precision and high-accuracy non-contact measurement of pipeline medium pressure, the detection resolution is greatly improved, and the ultrasonic surface wave only propagates in the surface layer of the pipe wall, the signal transmission loss is small, is not affected by the nature of the medium inside the pipeline, can effectively improve the accuracy of measurement results, can be used for electric vehicle related facility manufacturing, realizes high-accuracy non-contact measurement of pipeline fluid pressure measurement.

Description

Technical Field

[0001] This invention relates to a non-contact method and device for measuring the pressure of media inside a pipeline based on ultrasonic surface waves, belonging to the field of pressure detection technology. Background Technology

[0002] In pressure testing of liquids within pipelines, the conventional method involves installing pressure monitoring instruments on a closed, pressurized pipeline. These instruments utilize their sensing elements to directly measure the static pressure within the pipeline. This contact-type pressure measurement method uses a pressure gauge connected to a pre-existing pressure testing interface on the pipeline surface. However, due to pipeline structural limitations, a testing port must be pre-installed on the pipeline being tested, increasing processing and welding steps, raising costs, and increasing the risk of leakage. Furthermore, the testing interface, formed on the pipeline sidewall, can cause stress concentration at the testing port, making it a critical point for structural integrity.

[0003] To address the above issues, ultrasonic non-contact measurement can obtain medium pressure information by detecting ultrasonic signals, offering advantages such as avoiding potential leakage risks and reducing costs. However, in current research on ultrasonic non-contact pressure measurement, longitudinal wave transmission is relatively simple, and measurement is primarily performed using longitudinal waves. However, longitudinal wave measurement requires multiple passes through the transmission pipe wall and internal medium, resulting in significant signal loss, numerous stray signals, a low signal-to-noise ratio, and significant influence from medium properties and temperature. Summary of the Invention

[0004] The purpose of this invention is to provide a non-contact method and device for measuring the pressure of media inside a pipeline based on ultrasonic surface waves, which solves the problem that the accuracy of measurement results in the prior art needs to be improved.

[0005] The technical solution of this invention is:

[0006] A non-contact method for measuring the pressure of a medium inside a pipe based on ultrasonic surface waves includes the following steps:

[0007] S1. Fix the ultrasonic surface wave transceiver module TRA and the ultrasonic surface wave transceiver module TRB on the pipe under test, parallel to the central axis of the pipe under test;

[0008] S2. Start the measurement program on the industrial control computer, input the information of the pipeline under inspection, including the pipeline thickness H and the thickness correction parameter λ, and set the measurement threshold;

[0009] S3. When the medium in the pipeline under test is zero, a pressure zeroing operation is performed. The industrial control computer drives the ultrasonic surface wave transceiver module TRA and the ultrasonic surface wave transceiver module TRB to emit surface wave pulses respectively through the drive circuit. The output signals of the ultrasonic surface wave transceiver module TRA and the ultrasonic surface wave transceiver module TRB are amplified by the signal amplification circuit, acquired by the high-speed signal acquisition card, and input into the measurement program of the industrial control computer. The time signals of the ultrasonic surface wave transceiver module TRB and the ultrasonic surface wave transceiver module TRA are acquired, and the average is taken to obtain the ultrasonic surface wave propagation time t0 under zero pressure.

[0010] S4. When the pipeline under inspection is in working condition, i.e. when the pipeline medium is pressurized, the formal measurement begins. The industrial control computer controls the ultrasonic surface wave transceiver module TRA and the ultrasonic surface wave transceiver module TRB to emit surface wave pulses respectively. The time signals of the ultrasonic surface wave transceiver module TRB and the ultrasonic surface wave transceiver module TRA are collected to obtain the ultrasonic surface wave propagation time t when the pipeline pressure is P. The pressure value P of the medium in the pipeline in real time is calculated by the pressure calculation formula based on the thickness correction index. The final pressure value is obtained by averaging.

[0011] Further, in step S4, the pressure value P of the medium inside the pipeline in real time is calculated using the pressure calculation formula based on the thickness correction index, specifically as follows:

[0012] P = H -λ k(t-t0)

[0013] Where H is the pipe wall thickness, λ is the thickness correction parameter, k is the correlation coefficient between the ultrasonic surface wave propagation time and the pipe wall stress of the pipe under test, t0 is the ultrasonic surface wave propagation time under zero pressure, and t is the ultrasonic surface wave propagation time when the pipe pressure is P.

[0014] Furthermore, the thickness correction parameter λ is obtained by fitting the following experimental method: applying pressure to pipes of different thicknesses of the same material, measuring the magnitude of the pipe wall stress, and obtaining the thickness correction parameter of the pipe of this material by fitting multiple sets of pressure-stress data.

[0015] Furthermore, the correlation coefficient k between the ultrasonic surface wave propagation time and the pipe wall stress of the pipe under test is obtained by linear fitting of multiple sets of ultrasonic surface wave propagation times in the pipe wall using the least squares method.

[0016] Furthermore, in step S3, the industrial control computer's measurement program, based on the measurement threshold set in step S2, will stop detecting and prompt a fault if the difference between the measured values ​​of the two pulses transmitted in opposite directions exceeds the measurement threshold during actual pressure measurement. If the difference does not exceed the measurement threshold, the program will perform a set number of opposite transmission measurements and take the average value as the final measurement result.

[0017] Furthermore, in step S4, the pressure calculation formula based on the thickness correction index is obtained from the following:

[0018] Because the pressure value P of the medium inside the pipeline in real time has a linear relationship with the stress σ of the pipe wall:

[0019] P = k1(σ - σ0)

[0020] Where σ0 is the pipe wall stress under zero pressure, and k1 is the correlation coefficient between the internal pressure of the inspected pipe and the pipe wall stress. Since ultrasonic surface waves only propagate on the surface of the pipe wall, the correlation coefficient k1 is approximately expressed as an exponential function of the pipe wall thickness H, i.e.:

[0021] k1 = H -λ

[0022] Where λ is the thickness correction parameter;

[0023] According to the principle of acoustic elasticity:

[0024] Δσ=kΔt→σ-σ0=k(t-t0)

[0025] Where Δσ is the stress change, Δt is the propagation time change, k is the correlation coefficient between the ultrasonic surface wave propagation time and the pipe wall stress of the inspected pipe, t0 is the ultrasonic surface wave propagation time under zero pressure, and σ and t are the pipe wall stress and ultrasonic surface wave propagation time when the pipe pressure is P.

[0026] In summary, we can conclude that:

[0027] P = H -λ k(t-t0)

[0028] Where H is the pipe wall thickness, λ is the thickness correction parameter, k is the correlation coefficient between the ultrasonic surface wave propagation time and the pipe wall stress of the pipe under test, t0 is the ultrasonic surface wave propagation time under zero pressure, and t is the ultrasonic surface wave propagation time when the pipe pressure is P.

[0029] A non-contact pressure measuring device for a medium inside a pipeline based on ultrasonic surface waves, employing any of the methods described above, includes an industrial control computer, a drive circuit, a signal amplification circuit, a high-speed signal acquisition card, an ultrasonic surface wave transceiver module TRA, and an ultrasonic surface wave transceiver module TRB. The ultrasonic surface wave transceiver modules TRA and TRB are fixed parallel to each other on the pipe wall axis of the pipeline under inspection. The industrial control computer drives the ultrasonic surface wave transceiver modules TRA / TRB to excite ultrasonic surface waves, which are then transmitted to the ultrasonic surface wave transceiver modules TRB / TRA. After the ultrasonic surface wave signal is amplified by the signal amplification circuit, it is acquired by the high-speed signal acquisition card and input into the industrial control computer for calculating the pressure signal.

[0030] The beneficial effects of this invention are as follows: This non-contact measurement method and device for pipeline medium pressure based on ultrasonic surface waves can achieve high-precision and high-accuracy non-contact measurement of pipeline medium pressure. By using ultrasonic surface waves as the measurement means, which have the slowest speed compared to ultrasonic longitudinal and transverse waves, the detection resolution is greatly improved. Furthermore, ultrasonic surface waves only propagate on the surface of the pipe wall, resulting in low signal transmission loss and being unaffected by the properties of the medium inside the pipe, thus effectively improving the accuracy of the measurement results. Additionally, it possesses a self-checking function, eliminating random errors and ensuring high accuracy of the measurement results by setting thresholds and using a counter-current transmission measurement method. Attached Figure Description

[0031] Figure 1 This is a schematic flowchart of a non-contact method for measuring the pressure of a medium inside a pipe based on ultrasonic surface waves, according to an embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram illustrating the ultrasonic surface wave transceiver module TRA and the ultrasonic surface wave transceiver module TRB on the inspected pipeline in the embodiment.

[0033] Figure 3 This is a schematic diagram illustrating the non-contact measurement device for the pressure of the medium inside the pipe based on ultrasonic surface waves in the embodiment.

[0034] Among them, 1-Ultrasonic surface wave transceiver module TRA, 2-Ultrasonic surface wave transceiver module TRB, 3-The pipe under inspection. Detailed Implementation

[0035] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0036] The embodiment provides a non-contact method for measuring the pressure of a medium inside a pipe based on ultrasonic surface waves, such as... Figure 1 This includes the following steps:

[0037] S1. Fix the ultrasonic surface wave transceiver module TRA1 and the ultrasonic surface wave transceiver module TRB2 onto the pipe under test 3, parallel to the central axis of the pipe. Figure 2 .

[0038] In step S1, the distance between the ultrasonic surface wave transceiver module TRA1 and the ultrasonic surface wave transceiver module TRB2 is 10cm.

[0039] S2. Start the measurement program on the industrial control computer, input the information of the inspected pipe 3, including the pipe thickness H and the thickness correction parameter λ, and set the measurement threshold.

[0040] In step S2, the measurement threshold is the maximum permissible error, which can be set according to actual needs.

[0041] S3. When the medium in the inspected pipeline 3 is zero, a pressure zeroing operation is performed. The industrial control computer drives the ultrasonic surface wave transceiver module TRA1 and ultrasonic surface wave transceiver module TRB2 to emit surface wave pulses respectively through the drive circuit. The output signals of ultrasonic surface wave transceiver module TRA1 and ultrasonic surface wave transceiver module TRB2 are amplified by the signal amplification circuit, acquired by the high-speed signal acquisition card, and input into the measurement program of the industrial control computer. The time signals of ultrasonic surface wave transceiver module TRB2 and ultrasonic surface wave transceiver module TRA1 are acquired, and the average is taken to obtain the ultrasonic surface wave propagation time t0 under zero pressure.

[0042] In step S3, the industrial control computer's measurement program, based on the measurement threshold set in step S2, will stop detecting and indicate an instrument malfunction if the difference between the measured values ​​of two opposing pulses exceeds the measurement threshold during actual pressure measurement. If the difference does not exceed the measurement threshold, the program will perform a set number of opposing pulse measurements, such as 5, and take the average value as the final measurement result. By setting the measurement threshold, a self-checking function is implemented to ensure the accuracy of the measurement results.

[0043] S4. When the inspected pipeline 3 is in working condition, i.e. when the pipeline medium is pressurized, the formal measurement begins. The industrial control computer controls the ultrasonic surface wave transceiver module TRA1 and the ultrasonic surface wave transceiver module TRB2 to emit surface wave pulses respectively, and collects the time signals of the ultrasonic surface wave transceiver module TRB2 and the ultrasonic surface wave transceiver module TRA1 to obtain the ultrasonic surface wave propagation time t when the pipeline pressure is P. The pressure value P of the medium in the pipeline in real time is calculated by the pressure calculation formula based on the thickness correction index, and the final pressure value is obtained by averaging.

[0044] In step S4, the pressure value P of the medium inside the pipeline in real time is calculated using the pressure calculation formula based on the thickness correction index. Specifically,

[0045] P = H -λ k(t-t0)

[0046] Where H is the pipe wall thickness, λ is the thickness correction parameter, k is the correlation coefficient between the ultrasonic surface wave propagation time and the pipe wall stress of the pipe under test, t0 is the ultrasonic surface wave propagation time under zero pressure, and t is the ultrasonic surface wave propagation time when the pipe pressure is P.

[0047] The correlation coefficient k between the ultrasonic surface wave propagation time and the pipe wall stress of the pipe under test is obtained by linear fitting of multiple sets of ultrasonic surface waves in the pipe wall using the least squares method.

[0048] In step S4, the pressure calculation formula based on the thickness correction index is obtained as follows:

[0049] Because the pressure value P of the medium inside the pipeline in real time has a linear relationship with the stress σ of the pipe wall:

[0050] P = k1(σ - σ0)

[0051] Where σ0 is the pipe wall stress under zero pressure, and k1 is the correlation coefficient between the internal pressure of the inspected pipe 3 and the pipe wall stress. Since ultrasonic surface waves only propagate on the surface of the pipe wall, the correlation coefficient k1 is approximately expressed as an exponential function of the pipe wall thickness H, that is:

[0052] k1 = H -λ

[0053] Wherein, λ is the thickness correction parameter, which is only related to the pipe wall material. As the pipe wall thickness increases, the stress on the pipe wall surface decreases nonlinearly. The thickness correction parameter λ is obtained by fitting the following experimental method: apply pressure to pipes of the same material but different thicknesses, measure the pipe wall stress, and obtain the thickness correction parameter of the pipe of this material by fitting multiple sets of pressure-stress data.

[0054] According to the principle of acoustic elasticity:

[0055] Δσ=kΔt→σ-σ0=k(t-t0)

[0056] Where Δσ is the stress change, Δt is the propagation time change, k is the correlation coefficient between the ultrasonic surface wave propagation time and the pipe wall stress of the inspected pipe 3, t0 is the ultrasonic surface wave propagation time under zero pressure, and σ and t are the pipe wall stress and ultrasonic surface wave propagation time when the pipe pressure is P.

[0057] In summary, we can conclude that:

[0058] P = H -λ k(t-t0)

[0059] Where H is the pipe wall thickness, λ is the thickness correction parameter, k is the correlation coefficient between the ultrasonic surface wave propagation time and the pipe wall stress of the pipe under test, t0 is the ultrasonic surface wave propagation time under zero pressure, and t is the ultrasonic surface wave propagation time when the pipe pressure is P.

[0060] In step S4, surface wave propagation does not traverse the medium, eliminating the need for calibration for different media within the pipe. Therefore, the measurement process is less affected by various factors. Furthermore, since surface wave propagation is related to pipe wall stress, which in turn is related to pipe thickness, pressure values ​​obtained from pipes of different thicknesses will have relatively large errors without thickness correction. Therefore, introducing thickness as a variable into the calculation results, and applying thickness correction to the pressure calculation formula based on the thickness correction index, results in higher accuracy, better reflects real-world conditions, and is more reasonable, leading to higher reliability of the measurement results. In addition, employing a counter-transmission and reception measurement method reduces the impact of random environmental factors on the measurement process, improving the accuracy of the measurement results.

[0061] This non-contact measurement method for pipeline medium pressure based on ultrasonic surface waves can achieve high-precision and high-accuracy non-contact measurement of pipeline medium pressure. By using ultrasonic surface waves as the measurement means, which have the slowest speed compared to ultrasonic longitudinal and transverse waves, the detection resolution is greatly improved. Furthermore, ultrasonic surface waves only propagate on the pipe wall surface, resulting in low signal transmission loss and being unaffected by the properties of the medium inside the pipe, effectively improving the accuracy of the measurement results. It also features a self-checking function, eliminating random errors by setting thresholds and using a counter-current transmission measurement method, ensuring high accuracy of the measurement results.

[0062] like Figure 3 The embodiment also provides a non-contact measurement device for pipeline medium pressure based on ultrasonic surface waves, which employs any of the above methods. The device includes an industrial control computer, a drive circuit, a signal amplification circuit, a high-speed signal acquisition card, an ultrasonic surface wave transceiver module TRA1, and an ultrasonic surface wave transceiver module TRB2. The ultrasonic surface wave transceiver modules TRA1 and TRB2 are fixed parallel to each other on the pipe wall axis of the pipeline under inspection. The industrial control computer drives the ultrasonic surface wave transceiver modules TRA1 / TRB to excite ultrasonic surface waves, which are then transmitted to the ultrasonic surface wave transceiver modules TRB2 / TRA. After the ultrasonic surface wave signal is amplified by the signal amplification circuit, it is acquired by the high-speed signal acquisition card and input into the industrial control computer for calculating the pressure signal.

[0063] This non-contact measurement method and device for pipeline medium pressure based on ultrasonic surface waves calculates the real-time pressure value of the medium inside the pipeline using a pressure calculation formula based on a thickness correction index. It can achieve high-precision measurement of the pressure of the medium inside the pipeline and can be used in the manufacturing of electric vehicle-related facilities to achieve high-accuracy non-contact measurement of fluid pressure inside pipelines.

[0064] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A non-contact method for measuring the pressure of a medium inside a pipe based on ultrasonic surface waves, characterized in that: Includes the following steps, S1. Fix the ultrasonic surface wave transceiver module TRA and the ultrasonic surface wave transceiver module TRB to the pipe under test, parallel to the central axis of the pipe under test; S2. Start the measurement program on the industrial control computer, input the information of the pipeline under inspection, including the pipeline thickness H and the thickness correction parameter λ, and set the measurement threshold; S3. When the medium in the pipeline under test is zero, a pressure zeroing operation is performed. The industrial control computer drives the ultrasonic surface wave transceiver module TRA and the ultrasonic surface wave transceiver module TRB to transmit surface wave pulses respectively through the drive circuit. The measurement method of reciprocating transmission and reception is adopted. The output signals of the ultrasonic surface wave transceiver module TRA and the ultrasonic surface wave transceiver module TRB are amplified by the signal amplification circuit, acquired by the high-speed signal acquisition card, and input into the measurement program of the industrial control computer. The time signals of the ultrasonic surface wave transceiver module TRB and the ultrasonic surface wave transceiver module TRA are acquired, and the average is taken to obtain the ultrasonic surface wave propagation time t0 under zero pressure. S4. When the inspected pipeline is in working condition, i.e., when the pipeline medium is pressurized, the formal measurement begins. The industrial control computer controls the ultrasonic surface wave transceiver module TRA and the ultrasonic surface wave transceiver module TRB to transmit surface wave pulses respectively. The measurement method of reciprocating transmission and reception is adopted to collect the time signals of the ultrasonic surface wave transceiver module TRB and the ultrasonic surface wave transceiver module TRA to obtain the ultrasonic surface wave propagation time t when the pipeline pressure is P. Since the propagation of surface waves is related to the pipe wall stress, and the pipe wall stress is related to the pipe wall thickness, the pipe wall thickness H is introduced as a variable into the calculation results. The pressure value P of the medium in the pipeline in real time is calculated by the pressure calculation formula based on the thickness correction index. The final pressure value is obtained by averaging. In step S4, the pressure value P of the medium inside the pipeline in real time is calculated using the pressure calculation formula based on the thickness correction index. Specifically, ， Where H is the pipe wall thickness, and the thickness correction parameter λ is obtained by fitting the following experimental method: apply pressure to pipes of different thicknesses of the same material, measure the pipe wall stress, and obtain the thickness correction parameter of the pipe of this material by fitting multiple sets of pressure-stress data. k denoted as t0, where t0 is the ultrasonic surface wave propagation time under zero pressure and t is the ultrasonic surface wave propagation time when the pipe pressure is P.

2. The non-contact method for measuring the pressure of a medium inside a pipe based on ultrasonic surface waves as described in claim 1, characterized in that: Correlation coefficient between ultrasonic surface wave propagation time and pipe wall stress of the tested pipe k The value was obtained by linear fitting using the least squares method through multiple sets of ultrasonic surface waves propagating in the pipe wall.

3. The non-contact method for measuring the pressure of a medium inside a pipe based on ultrasonic surface waves as described in claim 1 or 2, characterized in that: In step S3, the industrial control computer's measurement program, based on the measurement threshold set in step S2, will stop detecting and prompt a fault if the difference between the measured values ​​of the two pulses transmitted in opposite directions exceeds the measurement threshold during actual pressure measurement. If the difference does not exceed the measurement threshold, the program will perform a set number of opposite transmission measurements and take the average value as the final measurement result.

4. The non-contact method for measuring the pressure of a medium inside a pipe based on ultrasonic surface waves as described in claim 1 or 2, characterized in that: In step S4, the pressure calculation formula based on the thickness correction index is obtained as follows: Because the pressure value P of the medium inside the pipeline in real time has a linear relationship with the stress σ of the pipe wall: ， in, The stress in the pipe wall under zero pressure is... This is the correlation coefficient between the internal pressure and wall stress of the inspected pipeline. Since ultrasonic surface waves only propagate on the surface of the pipe wall, the correlation coefficient... It can be approximately expressed as an exponential function of the pipe wall thickness H, that is: ， Where λ is the thickness correction parameter; According to the principle of acoustic elasticity: ， in, The stress change denoted as σ, where k is the correlation coefficient between the ultrasonic surface wave propagation time and the pipe wall stress of the inspected pipe, t0 is the ultrasonic surface wave propagation time under zero pressure, and σ and t are the pipe wall stress and ultrasonic surface wave propagation time when the pipe pressure is P. In summary, we can conclude that: ， Where H is the pipe wall thickness, and λ is the thickness correction parameter. k denoted as t0, where t0 is the ultrasonic surface wave propagation time under zero pressure and t is the ultrasonic surface wave propagation time when the pipe pressure is P.

5. A non-contact measuring device for intra-pipe medium pressure based on ultrasonic surface waves, employing the method described in any one of claims 1-4, characterized in that: It includes an industrial control computer, a drive circuit, a signal amplification circuit, a high-speed signal acquisition card, an ultrasonic surface wave transceiver module TRA, and an ultrasonic surface wave transceiver module TRB. The ultrasonic surface wave transceiver modules TRA and TRB are fixed parallel to the pipe wall axis of the pipeline under inspection. The industrial control computer drives the ultrasonic surface wave transceiver modules TRA / TRB to excite ultrasonic surface waves, which are transmitted to the ultrasonic surface wave transceiver modules TRB / TRA. After the ultrasonic surface wave signal is amplified by the signal amplification circuit, it is acquired by the high-speed signal acquisition card and input into the industrial control computer for calculating the pressure signal.

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