Ultrasonic measuring device and method for measuring pressure of liquid medium in a pipe

Abstract

The application discloses a kind of ultrasonic measuring device and measuring method of liquid medium pressure in pipeline, and measuring device includes wedge, temperature probe, ultrasonic array transducer, ultrasonic array transceiver, temperature transmitter, main control machine;The main control machine is connected with ultrasonic array transceiver, temperature transmitter respectively.This application is based on the linear relationship between pipe wall stress and liquid pressure in pipeline in a certain range, and the linear relationship between pipe wall stress and ultrasonic velocity in pipe wall in a certain range, finally the propagation time of ultrasonic transverse wave in pipe wall cross section is measured to detect the pressure value of liquid medium in pipeline.This application measures the liquid pressure in pipeline based on ultrasonic transverse wave, the propagation velocity is relatively slow, which improves the measurement accuracy;Ultrasonic transverse wave can only propagate in solid, avoid ultrasonic projection to pipeline medium to produce reflection and scattering and other clutter signals, which improves the reliability of measurement.

Description

Technical Field

[0001] This invention belongs to the technical field of metrology and testing, specifically relating to an ultrasonic measuring device and method for measuring the pressure of liquid media in a pipeline. Background Technology

[0002] Hydraulic system operation monitoring and fault diagnosis require the detection of various system parameters, with pressure being one of the most important. Most domestic hydraulic systems lack measurement interfaces at the required locations, significantly limiting the effectiveness of currently widely used interventional measurement methods in fault location and troubleshooting.

[0003] Non-invasive pressure measurement mainly includes resistance strain gauge method and ultrasonic method. Resistance strain gauge method has high requirements for strain gauge installation and weak detection signal, thus its versatility and reliability are not high. Ultrasonic external pipe measurement obtains oil pressure information by detecting ultrasonic echoes, and has advantages such as not disrupting the fluid flow field, no mechanical inertia, fast transient response, strong dynamic measurement capability, and convenient installation. Currently, research on ultrasonic non-invasive pressure measurement mainly falls into two categories: one is to study the different acoustic characteristics of liquids in pipes under different pressures using ultrasonic longitudinal waves, establishing the relationship between pressure and ultrasonic velocity through a large amount of experimental data; the other is to study the acoustic characteristics of the pipe wall under indeterminate pressure, ultimately calculating the pressure value of the liquid in the pipe by measuring the propagation speed of ultrasonic waves in the pipe wall.

[0004] In current research on non-invasive ultrasound measurement, longitudinal waves are generally used for measurement because their emission is relatively simple. However, longitudinal waves are reflected and refracted at the solid-liquid interface, resulting in high noise in the received signal and low measurement accuracy. At the same time, metal tubes are prone to corrosion and thinning or thickening due to dirt deposits during use, which can cause changes in the sound path in the solid and liquid, leading to serious drift in pressure measurement results. Summary of the Invention

[0005] The purpose of this invention is to provide an ultrasonic measuring device and method for measuring the pressure of liquid media inside a pipeline, aiming to solve the aforementioned problems. This invention is based on the linear relationship between pipe wall stress and liquid pressure within a certain range, and the linear relationship between pipe wall stress and the speed of sound in the pipe wall within a certain range. Ultimately, the pressure value of the liquid medium inside the pipeline is detected by measuring the propagation time of the ultrasonic transverse wave in the cross-section of the pipe wall.

[0006] This invention is mainly achieved through the following technical solutions:

[0007] An ultrasonic measuring device for measuring the pressure of a liquid medium in a pipeline includes a wedge, a temperature probe, an ultrasonic array transducer, an ultrasonic array transceiver, a temperature transmitter, and a main control unit. The main control unit is connected to the ultrasonic array transceiver and the temperature transmitter. The ultrasonic array transducer is mounted on the top of the wedge, and the bottom of the wedge has an arc-shaped structure. A temperature probe is installed on the pipeline on one side of the wedge, and the ultrasonic array transceiver and the temperature transmitter are connected to the ultrasonic array transducer and the temperature probe, respectively.

[0008] During the testing process, the temperature probe is attached to the pipe wall surface, and the ultrasonic array transducer is installed on the pipe wall surface via wedges. The main control unit controls the ultrasonic array transceiver to excite the ultrasonic array transducer to emit ultrasonic longitudinal waves at a specific angle, thereby generating ultrasonic transverse waves in the pipe wall of the pipe under test. The transverse waves return to the ultrasonic array transducer via a polygonal path. The ultrasonic array transceiver sends the received transverse wave echo data and the temperature data detected by the temperature transmitter to the main control unit, respectively. The main control unit calculates the propagation time of the ultrasonic transverse waves in the pipe wall using autocorrelation and temperature compensation algorithms.

[0009] This invention is mainly achieved through the following technical solutions:

[0010] An ultrasonic method for measuring the pressure of a liquid medium inside a pipeline, using the aforementioned measuring device, includes the following steps:

[0011] Step S100: Based on the materials of the pipe to be tested and the wedge, calculate the first critical angle and the second critical angle of the ultrasonic wave, and determine the emission angle range of the transverse wave generated by the ultrasonic array transducer.

[0012] Step S200: A longitudinal wave perpendicular to the surface of the pipe wall is emitted through an ultrasonic array transducer, and the pipe wall thickness is calculated.

[0013] Step S300: Based on the outer diameter of the pipe wall to be tested and the pipe wall thickness calculated in step S200, adjust the emission angle of the transverse wave generated by the ultrasonic array transducer in step S100 so that the transverse wave generated by the ultrasonic array transducer in the pipe wall propagates in a polygonal path.

[0014] Step S400: Select multiple test pipes with the same material and outer diameter as the pipe to be tested, but different wall thicknesses, for testing;

[0015] Step S500: Under zero stress, select a cross-section of the test pipe as the ultrasonic measurement area; measure the pipe wall thickness B using the method in step S200; measure the propagation time of the ultrasonic refracted shear wave corresponding to different wall thicknesses under zero stress; and fit the relationship between the propagation time of the ultrasonic refracted shear wave in the pipe wall and the pipe wall thickness under zero stress at temperature T0.t 0 =a*B+b Where 'a' is the proportionality coefficient, representing the change in propagation time caused by a unit change in thickness; 'b' is the intercept, representing the theoretical propagation time when the pipe wall thickness is zero; and 'B' is the pipe wall thickness. This allows us to obtain the propagation time of a zero-stress ultrasonic shear wave in the pipe wall at temperature T0. t 0;

[0016] Step S600: Select any section of the pipe under test as the measurement area for the ultrasonic shear wave. Similarly, measure the propagation time of the ultrasonic shear wave in the pipe wall. t ;

[0017] Step S700: Based on the internal pressure of the pipeline p With the internal stress of the pipe wall s Theoretically, they have a linear relationship:

[0018] p=k 1 *s

[0019] in, k 1 represents the correlation coefficient between the internal pressure and internal stress of the pipeline;

[0020] According to acoustic bomb theory:

[0021] s-s 0 =k 2 (tt 0 )

[0022] in, k 2 represents the correlation coefficient between the propagation time of ultrasonic shear waves in the pipe wall and the pipe wall stress.

[0023] s 0 Zero stress

[0024] s For pipe wall stress,

[0025] t The propagation time of the ultrasonic transverse wave in the pipe wall;

[0026] Ultimately, we can conclude that:

[0027] p=k(tt 0 )+c

[0028] in: k This refers to the fluid pressure coefficient in the pipeline. c The ultrasonic propagation coefficient;

[0029] Step S800: Perform a pressure test in the test pipeline by changing the internal hydraulic pressure.p The magnitude of the ultrasonic transverse wave was determined, and multiple sets of ultrasonic transverse wave propagation data in the pipe wall were obtained. Linear fitting was performed using the least squares method to obtain the coefficients between the pipe liquid pressure and the ultrasonic propagation time in step S700. k and c The value is then used to calculate the pressure of the liquid inside the pipe being tested.

[0030] To better realize the present invention, in step S200, the pipe wall thickness is calculated using the following formula:

[0031]

[0032] Where t1 is the time point when the first echo is received, and t2 is the time point when the second echo is received;

[0033] C represents the sound velocity of the ultrasonic longitudinal wave in the pipe wall material.

[0034] To better realize the present invention, further, in step S500, the measuring device is installed on the test pipe, and the ultrasonic array transceiver is controlled to excite the ultrasonic array transducer to generate an ultrasonic longitudinal wave at a certain angle, which is converted into a transverse wave in the zero-stress test block; the transverse wave propagates through a polygon and is finally received by the ultrasonic array transducer. The ultrasonic array transceiver sends the received transverse wave echo data to the main control computer. The main control computer calculates the propagation time of the ultrasonic refracted transverse wave in the pipe wall through the autocorrelation algorithm and the temperature compensation algorithm.

[0035] To better implement this invention, the temperature compensation algorithm further includes the following steps:

[0036] The propagation time of ultrasonic transverse waves within the pipe wall is linearly related to the temperature of the pipe wall.

[0037] t=t'+r *Δ T

[0038] in, r This is the temperature compensation coefficient;

[0039] Δ T This is the difference between the temperature of the pipe being measured and the temperature at the time of calibration during actual measurement.

[0040] t' The time it takes for the ultrasonic transverse wave to propagate through the tube wall is calculated using an autocorrelation algorithm during actual measurement.

[0041] To better realize the present invention, further, within the set temperature range, 16 evenly distributed points on the pipe wall are selected as test points. The temperature of the constant temperature chamber is changed, and after the temperature of the constant temperature chamber reaches the set point, the process continues to wait until the temperature of the pipe wall and the temperature inside the chamber are consistent. The propagation time of the ultrasonic transverse wave in the pipe wall is measured. By changing the temperature of the constant temperature chamber three times in a cycle, the propagation time of the ultrasonic transverse wave at each temperature point is recorded, and a linear relationship formula between the propagation time of the ultrasonic transverse wave in the pipe wall and the temperature of the pipe wall is obtained by fitting.

[0042] To better realize the present invention, the wall thickness of the pipe to be tested is further greater than 2 mm.

[0043] The beneficial effects of this invention are as follows:

[0044] (1) The present invention measures the liquid pressure in the pipe based on the transverse wave of ultrasonic waves. The propagation speed is relatively slower than that of the longitudinal wave of ultrasonic waves, which improves the measurement accuracy. The transverse wave of ultrasonic waves can only propagate in solids, avoiding the generation of clutter signals such as reflection and scattering when the ultrasonic waves are projected into the pipe medium, thus improving the reliability of the measurement.

[0045] (2) The present invention calculates the pressure value of the liquid in the pipe by measuring the propagation time of the ultrasonic transverse wave in the entire cross section of the pipe wall, thus avoiding measurement errors caused by uneven stress distribution in the pipe wall;

[0046] (3) The present invention uses an ultrasonic linear array transducer. By using phased array technology, the emission time phase of the built-in chip can be changed, and the emission angle of the ultrasonic longitudinal wave can be adjusted arbitrarily within a certain range. When using a single transducer, the wall thickness and the propagation time of the ultrasonic transverse wave can be measured. Attached Figure Description

[0047] Figure 1 This is a schematic diagram illustrating the testing principle of the present invention;

[0048] Figure 2 This is a schematic diagram of the propagation path of a transverse wave in an ultrasonic cross section.

[0049] Figure 3 This is a flowchart of the ultrasonic pressure measurement process of the present invention.

[0050] Wherein: 1-ultrasonic array transducer, 2-wedge, 3-pipe wall, 4-ultrasonic transverse wave transmission path, 5-temperature probe. Detailed Implementation Example 1:

[0051] An ultrasonic method for measuring the pressure of a liquid medium inside a pipeline, using the aforementioned measuring device, includes the following steps:

[0052] Step S100: Based on the materials of the pipe to be tested and the wedge 2, calculate the first critical angle and the second critical angle of the ultrasonic wave, and determine the emission angle range of the transverse wave generated by the ultrasonic array transducer 1.

[0053] Step S200: A longitudinal wave perpendicular to the surface of the pipe wall 3 under test is emitted through the ultrasonic array transducer 1, and the thickness of the pipe wall 3 is calculated.

[0054] Step S300: Based on the outer diameter of the pipe wall 3 of the pipe to be tested and the thickness of the pipe wall 3 calculated in step S200, adjust the emission angle of the transverse wave generated by the ultrasonic array transducer 1 in step S100 so that the transverse wave generated by the ultrasonic array transducer 1 in the pipe wall 3 propagates in a polygonal path.

[0055] Step S400: Select multiple test pipes with the same material and outer diameter as the pipe to be tested, but different wall thicknesses, for testing;

[0056] Step S500: Under zero stress, select a cross-section of the test pipe as the ultrasonic measurement area; measure the pipe wall thickness B using the method in step S200; measure the propagation time of the ultrasonic refracted shear wave corresponding to different wall thicknesses under zero stress; and fit the relationship between the propagation time of the ultrasonic refracted shear wave in the pipe wall 3 and the pipe wall thickness under zero stress at temperature T0. t 0 =a*B+b Where 'a' is the proportionality coefficient, representing the change in propagation time caused by a unit change in thickness; 'b' is the intercept, representing the theoretical propagation time when the pipe wall thickness is zero; and 'B' is the pipe wall thickness. This allows us to obtain the propagation time of the zero-stress ultrasonic shear wave in the pipe wall 3 of the tested pipe at temperature T0. t 0;

[0057] Step S600: Select any section on the pipe under test as the measurement area for the ultrasonic shear wave. Similarly, measure the propagation time of the ultrasonic shear wave in the pipe wall 3 of the pipe under test. t ;

[0058] Step S700: Based on the internal pressure of the pipeline p Internal stress of pipe wall 3 s Theoretically, they have a linear relationship:

[0059] p=k 1 *s

[0060] in, k 1 represents the correlation coefficient between the internal pressure and internal stress of the pipeline;

[0061] According to acoustic bomb theory:

[0062] s-s 0=k 2 (tt 0 )

[0063] in, k 2 represents the correlation coefficient between the propagation time of ultrasonic shear waves in the pipe wall and the pipe wall stress. s 0 Zero stress s For pipe wall stress, t The propagation time of the ultrasonic transverse wave in the pipe wall;

[0064] Ultimately, we can conclude that:

[0065] p=k(tt 0 )+c

[0066] in: k This refers to the fluid pressure coefficient in the pipeline. c The ultrasonic propagation coefficient;

[0067] Step S800: Perform a pressure test in the test pipeline by changing the internal hydraulic pressure. p The magnitude of the ultrasonic transverse wave was determined, and multiple sets of propagation data of the ultrasonic transverse wave in the pipe wall 3 were obtained. Linear fitting was performed using the least squares method to obtain the coefficients between the pipe liquid pressure and the ultrasonic propagation time in step S700. k and c The value is then used to calculate the pressure of the liquid inside the pipe being tested.

[0068] Preferably, in step S200, the thickness of the pipe wall 3 is calculated using the following formula:

[0069]

[0070] Where t1 is the time point when the first echo is received, and t2 is the time point when the second echo is received;

[0071] C represents the sound velocity of the ultrasonic longitudinal wave in the pipe wall material 3.

[0072] This invention is based on the linear relationship between the stress in the pipe wall (3) and the liquid pressure inside the pipe within a certain range. Furthermore, the stress in the pipe wall (3) is also linearly related to the sound velocity of ultrasound within the pipe wall (3) within a certain range. Finally, the pressure of the liquid medium inside the pipe is detected by measuring the propagation time of the ultrasonic transverse wave in the cross-section of the pipe wall (3). This invention measures the liquid pressure inside the pipe based on ultrasonic transverse waves, whose propagation speed is relatively slower than that of ultrasonic longitudinal waves, thus improving measurement accuracy. Ultrasonic transverse waves can only propagate in solids, avoiding the generation of clutter signals such as reflection and scattering when the ultrasound is projected into the pipe medium, thereby improving the reliability of the measurement. Example

[0073] An ultrasonic method for measuring the pressure of a liquid medium inside a pipeline, using a measuring device, such as... Figure 3 As shown, it includes the following steps:

[0074] The wall thickness B of the pipe under test is measured by direct longitudinal wave ultrasonic waves.

[0075] The ultrasonic emission angle α is determined based on the pipe wall thickness B and the pipe diameter of the pipe to be tested.

[0076] Pipes of the same material and outer diameter but different wall thicknesses were selected as test pipes. Ultrasonic waves were emitted at an angle α, and the propagation time of zero-stress ultrasonic shear waves at temperature T0 was measured in test pipes with different wall thicknesses. Then, a formula for calculating the propagation time of zero-stress ultrasonic shear waves in the pipe wall 3 relative to the pipe wall thickness was obtained by fitting the data. Thus, the propagation time of zero-stress ultrasonic shear waves in the pipe wall 3 of the test pipe at temperature T0 was calculated. t 0;

[0077] The propagation time t' of the ultrasonic shear wave in the pipe wall 3 under different pressures was measured, and the time t was obtained after temperature compensation correction; thus, the propagation time of the ultrasonic shear wave in the pipe wall 3 of the pipe under test was obtained. t ;

[0078] Through formula p=k(tt 0 )+b The internal pressure value of the pipe is calculated, where the coefficient is... k and b The solution was obtained through multiple calibration and calculations.

[0079] Preferably, a pressure test is conducted in the test pipeline, by changing the internal hydraulic pressure. p The magnitude of the ultrasonic transverse wave was determined, and multiple sets of propagation data of the ultrasonic transverse wave in the pipe wall 3 were obtained. Linear fitting was performed using the least squares method to obtain the coefficients between the pipe liquid pressure and the ultrasonic propagation time in step 5. k and b The pressure value of the liquid inside the pipe under test is then calculated.

[0080] This invention is based on the linear relationship between the stress in the pipe wall (3) and the liquid pressure inside the pipe within a certain range. Furthermore, the stress in the pipe wall (3) is also linearly related to the sound velocity of ultrasound within the pipe wall (3) within a certain range. Finally, the pressure of the liquid medium inside the pipe is detected by measuring the propagation time of the ultrasonic transverse wave in the cross-section of the pipe wall (3). This invention measures the liquid pressure inside the pipe based on ultrasonic transverse waves, whose propagation speed is relatively slower than that of ultrasonic longitudinal waves, thus improving measurement accuracy. Ultrasonic transverse waves can only propagate in solids, avoiding the generation of clutter signals such as reflection and scattering when the ultrasound is projected into the pipe medium, thereby improving the reliability of the measurement. Example 2:

[0081] An ultrasonic measuring device for measuring the pressure of a liquid medium inside a pipeline, such as Figure 1 , Figure 2 As shown, the device includes a wedge 2, a temperature probe 5, an ultrasonic array transceiver 1, an ultrasonic array transceiver, a temperature transmitter, and a main control unit. The main control unit is connected to the ultrasonic array transceiver and the temperature transmitter. The ultrasonic array transceiver 1 is installed on the top of the wedge 2, and the bottom has an arc-shaped structure for fitting against the outer wall of the pipe. A temperature probe 5 is installed on the pipe on one side of the wedge 2. The ultrasonic array transceiver and the temperature transmitter are connected to the ultrasonic array transceiver 1 and the temperature probe 5, respectively.

[0082] The ultrasonic array transceiver is used to control the transmission of ultrasonic waves and send the acquired received data to the main control unit. The main control unit is used to compensate for the received data sent by the ultrasonic array transceiver with the temperature of the pipe wall 3 collected by the temperature transmitter, and finally obtain the propagation time of the ultrasonic transverse wave. Finally, the pressure value of the liquid medium inside the pipe under test is calculated by the relationship established by the experimental data.

[0083] During the test, the temperature probe 5 is attached to the surface of the pipe wall 3, and the ultrasonic array transducer 1 is installed on the surface of the pipe wall 3 via the wedge 2. The main control unit controls the ultrasonic array transceiver to excite the ultrasonic array transducer 1 to emit ultrasonic longitudinal waves at a specific angle, thereby generating ultrasonic transverse waves in the pipe wall 3 of the pipe under test. The transverse waves return to the ultrasonic array transducer 1 through a polygonal path. The ultrasonic array transceiver sends the received transverse wave echo data and the temperature data detected by the temperature transmitter to the main control unit respectively. The main control unit calculates the propagation time of the ultrasonic transverse waves in the pipe wall 3 through autocorrelation algorithm and temperature compensation algorithm.

[0084] An ultrasonic measurement method for the pressure of a liquid medium inside a pipeline, using the aforementioned measuring device, such as... Figure 3 As shown, it includes the following steps:

[0085] Step 1: Based on the material of the pipe and the material of the wedge 2, calculate the first critical angle and the second critical angle of the ultrasonic wave, and determine the emission angle range of the transverse wave generated by the ultrasonic array transducer 1.

[0086] Step 2: A longitudinal wave perpendicular to the surface of the pipe wall 3 is emitted through the ultrasonic array transducer 1. The time interpolation of the first and second echoes is measured using the formula... The thickness of the pipe wall 3 is calculated, where C is the sound velocity of the ultrasonic longitudinal wave in the material of the pipe wall 3, t1 is the time point when the first echo is received, and t2 is the time point when the second echo is received.

[0087] Step 3: Based on the outer diameter of pipe wall 3 and the input thickness of pipe wall 3, adjust the emission angle of ultrasonic array transducer 1 so that the transverse wave generated by ultrasonic array transducer 1 in pipe wall 3 propagates along a polygonal path, such as... Figure 2 As shown, the ultrasonic transverse wave transmission path 4 is a polygonal path.

[0088] Step 4: Select the same material as the pipe being tested to make multiple test pipes with the same outer diameter but different wall thicknesses.

[0089] Step 5: Under zero stress, select a cross-section of the test pipe as the ultrasonic measurement area. Install the ultrasonic array transducer 1 and wedge 2 on the test pipe. Control the ultrasonic array transceiver to excite the ultrasonic array transducer 1 to generate ultrasonic longitudinal waves at a certain angle. These waves are converted into transverse waves in the zero-stress test block, propagate through a polygon, and are received by the ultrasonic array transducer 1. The ultrasonic array transceiver sends the received transverse wave echo data to the main control computer. The main control computer calculates the propagation time T0 of the ultrasonic refracted transverse wave corresponding to the zero-stress condition of the zero-stress test block using zero-phase filtering and autocorrelation algorithms. Simultaneously, control the ultrasonic array transceiver to excite the ultrasonic array transducer 1 to emit longitudinal waves perpendicular to the test pipe wall 3. Measure the pipe wall thickness B of the test pipe in Step 2. Measure the ultrasonic transverse wave propagation time under zero stress in test pipes with different pipe wall thicknesses to obtain the propagation time of the ultrasonic transverse wave in the pipe wall 3 under zero stress. t 0 =a*B+b .

[0090] Step Six: Select any section of the pipe under test as the measurement area for ultrasonic shear waves. The temperature probe 5 is attached to the surface of the pipe wall 3, and the other end is connected to the temperature transmitter. The ultrasonic array transducer 1 is installed on the surface of the pipe wall 3 through the wedge block 2, and the other end is connected to the ultrasonic array transceiver. The main control unit controls the ultrasonic array transceiver to excite the ultrasonic array transducer 1 and emit ultrasonic longitudinal waves at a specific angle, generating ultrasonic shear waves in the pipe wall 3. The waves return to the array ultrasonic transducer through a polygonal path. The ultrasonic array transceiver sends the received shear wave echo data and the temperature data from the temperature transmitter to the main control unit. The main control unit calculates the propagation time t of the ultrasonic shear wave in the pipe wall 3 through autocorrelation algorithm and temperature compensation algorithm.

[0091] Step 7: Based on the theoretical linear relationship between the internal pressure p of the pipe and the internal stress of the pipe wall 3: p=k1*σ; according to the acoustic elasticity theory: σ-σ0=k2(t-t0), we can finally obtain p=k(t-t0)+b.

[0092] Step 8: Conduct a pressure test in the test pipeline. By changing the internal hydraulic pressure p, obtain multiple sets of ultrasonic shear wave propagation data t in the pipe wall 3. Perform linear fitting using the least squares method to obtain the coefficients k and b values ​​of the pipeline liquid pressure and ultrasonic propagation time. Based on the t value of the tested pipeline obtained in Step 6, calculate the liquid pressure p inside the pipeline.

[0093] Furthermore, the test pipes are made of different materials, have different diameters, and have a wall thickness greater than 2 mm.

[0094] Furthermore, the time t obtained in step six is ​​a value after temperature calibration. The calibration process is as follows: through a large number of experiments, it can be found that the propagation time of the ultrasonic transverse wave in the pipe wall 3 is linearly related to the temperature of the pipe wall 3, that is, t=t'+r*ΔT, where r is the temperature compensation coefficient, ΔT is the temperature difference between the temperature of the measured pipe during actual measurement and the temperature during calibration, and t' is the propagation time of the ultrasonic transverse wave in the pipe wall 3 calculated by relevant algorithms during actual measurement.

[0095] This invention is based on the linear relationship between the stress in the pipe wall (3) and the liquid pressure inside the pipe within a certain range. Furthermore, the stress in the pipe wall (3) is also linearly related to the sound velocity of ultrasound within the pipe wall (3) within a certain range. Finally, the pressure of the liquid medium inside the pipe is detected by measuring the propagation time of the ultrasonic transverse wave in the cross-section of the pipe wall (3). This invention measures the liquid pressure inside the pipe based on ultrasonic transverse waves, whose propagation speed is relatively slower than that of ultrasonic longitudinal waves, thus improving measurement accuracy. Ultrasonic transverse waves can only propagate in solids, avoiding the generation of clutter signals such as reflection and scattering when the ultrasound is projected into the pipe medium, thereby improving the reliability of the measurement. Example 3:

[0096] An ultrasonic measurement method for the pressure of a liquid medium inside a pipeline, using the aforementioned measuring device, employs two types of stainless steel pipes: one with a diameter of 60 mm and a wall thickness of 5 mm and 12 mm. The ultrasonic one-dimensional linear probe is selected with a frequency of 2.5 MHz and 16 elements. The method includes the following steps:

[0097] Step 1: Based on the stainless steel material of the pipe and the plexiglass material of the wedge 2, the first critical angle of the ultrasonic wave is calculated to be 27.6° and the second critical angle is 57.7°. When the emission angle is between 27.6° and 57.7°, only ultrasonic transverse waves are present in the pipe wall 3.

[0098] Step 2: A longitudinal wave perpendicular to the surface of the pipe wall 3 is emitted through the ultrasonic array transducer 1. The time interpolation of the first and second echoes is measured using the formula... The thickness of the pipe wall 3 is calculated, where C is the sound velocity of the ultrasonic longitudinal wave in the material of the pipe wall 3, t1 is the time point when the first echo is received, and t2 is the time point when the second echo is received.

[0099] Step 3: Based on the outer diameter of the tube wall 3 and the input thickness of the tube wall 3, adjust the emission angle of the ultrasonic array transducer 1 so that the transverse wave generated by the ultrasonic array transducer 1 in the tube wall 3 propagates in a polygonal path.

[0100] Step 4: Select the same material as the pipe being tested to make multiple test pipes with the same outer diameter but different wall thicknesses;

[0101] Step 5: Under zero stress, select a cross-section of the test pipe as the ultrasonic measurement area. Install the ultrasonic array transducer 1 and wedge 2 on the test pipe. Control the ultrasonic array transceiver to excite the ultrasonic array transducer 1 to generate ultrasonic longitudinal waves at a certain angle. These waves are converted into transverse waves in the zero-stress test block, propagate through a polygon, and are received by the ultrasonic array transducer 1. The ultrasonic array transceiver sends the received echo transverse wave data to the main control computer. The main control computer calculates the propagation time T0 of the ultrasonic refracted transverse wave corresponding to the zero-stress condition of the zero-stress test block using zero-phase filtering and autocorrelation algorithms. Simultaneously, by controlling the ultrasonic array transceiver to excite the ultrasonic array transducer 1 to emit longitudinal waves perpendicular to the test pipe wall 3, and through step 2, measure the thickness B of the pipe wall 3. Measure the propagation time of the ultrasonic transverse waves under zero stress in test pipes with different pipe wall 3 thicknesses to obtain the propagation time of the ultrasonic transverse waves in the pipe wall 3 under zero stress. t 0 =a*B+b ;

[0102] Step Six: Select any section of the pipe under test as the measurement area for ultrasonic shear waves. The temperature probe 5 is attached to the surface of the pipe wall 3, and the other end is connected to the temperature transmitter. The ultrasonic array transducer 1 is installed on the surface of the pipe wall 3 through the wedge block 2, and the other end is connected to the ultrasonic array transceiver. The main control unit controls the ultrasonic array transceiver to excite the ultrasonic array transducer 1 and emit ultrasonic longitudinal waves at a specific angle, generating ultrasonic shear waves in the pipe wall 3. The waves return to the array ultrasonic transducer through a polygonal path. The ultrasonic array transceiver sends the received echo shear wave data and the temperature data from the temperature transmitter to the main control unit. The main control unit calculates the propagation time t of the ultrasonic shear wave in the pipe wall 3 through autocorrelation algorithm and temperature compensation algorithm.

[0103] Step 7: Based on the theoretically linear relationship between the internal pressure p of the pipe and the internal stress of the pipe wall 3: p = k1 * σ; according to the acoustic elasticity theory: σ - σ0 = k2(t - t0), we can finally derive p = k(t - t0) + b:

[0104] Step 8: Conduct a pressure test in the test pipeline, using red hydraulic oil as the pressurizing medium. Perform five cycles of pressurization at eight pressure points uniformly within the range of 0-40 MPa. At each pressure point, acquire the propagation data (t-value) of the ultrasonic transverse wave in the pipe wall 3. Using the formula p=k(t-t0)+b derived in Step 7, perform linear fitting using the least squares method to calculate the coefficients k and b between the pipeline liquid pressure and the ultrasonic wave propagation time. Based on the t-value of the tested pipeline obtained in Step 6, calculate the pressure value p of the liquid inside the pipeline.

[0105] Furthermore, the test pipes are made of different materials, have different diameters, and have a wall thickness greater than 2 mm.

[0106] Furthermore, the time t mentioned is a value after temperature calibration. The calibration conditions are: using a Class A platinum resistance thermometer as the temperature probe 5, and operating within a constant temperature chamber; the calibration process is as follows:

[0107] Sixteen evenly distributed points were selected within a temperature range of 0~40℃. The temperature of the constant temperature chamber was changed, and after the temperature of the chamber reached the set point, the temperature of the pipe wall 3 and the internal temperature of the chamber were kept consistent. The propagation time of the ultrasonic transverse wave in the pipe wall 3 was measured. The temperature was changed three times in a cycle, and the propagation time of the ultrasonic transverse wave at each temperature point was recorded. By observing the recorded data, it can be found that the propagation time of the ultrasonic transverse wave in the pipe wall 3 and the temperature of the pipe wall 3 are linearly related, i.e., t=t'+r*ΔT, where r is the temperature compensation coefficient, ΔT is the temperature difference between the actual temperature of the pipe being measured and the temperature at the time of calibration, and t' is the propagation time of the ultrasonic transverse wave in the pipe wall 3 calculated by the relevant algorithm during the actual measurement.

[0108] This invention is based on the linear relationship between the stress in the pipe wall (3) and the liquid pressure inside the pipe within a certain range. Furthermore, the stress in the pipe wall (3) is also linearly related to the sound velocity of ultrasound within the pipe wall (3) within a certain range. Finally, the pressure of the liquid medium inside the pipe is detected by measuring the propagation time of the ultrasonic transverse wave in the cross-section of the pipe wall (3). This invention measures the liquid pressure inside the pipe based on ultrasonic transverse waves, whose propagation speed is relatively slower than that of ultrasonic longitudinal waves, thus improving measurement accuracy. Ultrasonic transverse waves can only propagate in solids, avoiding the generation of clutter signals such as reflection and scattering when the ultrasound is projected into the pipe medium, thereby improving the reliability of the measurement.

[0109] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. An ultrasonic method for measuring the pressure of a liquid medium inside a pipeline, characterized in that, The measurement is performed using a measuring device, which includes a wedge, a temperature probe, an ultrasonic array transducer, an ultrasonic array transceiver, a temperature transmitter, and a main control unit. The main control unit is connected to the ultrasonic array transceiver and the temperature transmitter, respectively. The ultrasonic array transducer is mounted on the top of the wedge, and the bottom has an arc-shaped structure. A temperature probe is installed on a pipe on one side of the wedge, and the ultrasonic array transceiver and the temperature transmitter are connected to the ultrasonic array transducer and the temperature probe, respectively. The measurement method includes the following steps: Step S100: Based on the materials of the pipe to be tested and the wedge, calculate the first critical angle and the second critical angle of the ultrasonic wave, and determine the emission angle range of the transverse wave generated by the ultrasonic array transducer. Step S200: A longitudinal wave perpendicular to the surface of the pipe wall is emitted through an ultrasonic array transducer, and the pipe wall thickness is calculated. Step S300: Based on the outer diameter of the pipe wall to be tested and the pipe wall thickness calculated in step S200, adjust the emission angle of the transverse wave generated by the ultrasonic array transducer in step S100 so that the transverse wave generated by the ultrasonic array transducer in the pipe wall propagates in a polygonal path. Step S400: Select multiple test pipes with the same material and outer diameter as the pipe to be tested, but different wall thicknesses, for testing; Step S500: Under zero stress, select a cross-section of the test pipe as the ultrasonic measurement area; measure the pipe wall thickness B using the method in step S200; measure the propagation time of the ultrasonic refracted shear wave corresponding to different wall thicknesses under zero stress; and fit the relationship between the propagation time of the ultrasonic refracted shear wave in the pipe wall and the pipe wall thickness under zero stress at temperature T0. t 0 =a*B+b Where 'a' is the proportionality coefficient, representing the change in propagation time caused by a unit change in thickness; 'b' is the intercept, representing the theoretical propagation time when the pipe wall thickness is zero; and 'B' is the pipe wall thickness. This allows us to obtain the propagation time of a zero-stress ultrasonic shear wave in the pipe wall at temperature T0. t 0; Step S600: Select any section of the pipe under test as the measurement area for the ultrasonic shear wave. Similarly, measure the propagation time of the ultrasonic shear wave in the pipe wall. t ; Step S700: Based on the internal pressure of the pipeline p With the internal stress of the pipe wall σ Theoretically, they have a linear relationship: p=k 1 *σ in, k 1 represents the correlation coefficient between the internal pressure and internal stress of the pipeline; According to acoustic bomb theory: σ-σ 0 =k 2 (tt 0 ) in, k 2 represents the correlation coefficient between the propagation time of ultrasonic shear waves in the pipe wall and the pipe wall stress. σ 0 Zero stress σ For pipe wall stress; Ultimately, we can conclude that: p=k(tt 0 )+c in: k This refers to the fluid pressure coefficient in the pipeline. c The ultrasonic propagation coefficient; Step S800: Perform a pressure test in the test pipeline by changing the internal hydraulic pressure. p The magnitude of the ultrasonic transverse wave was determined, and multiple sets of ultrasonic transverse wave propagation data in the pipe wall were obtained. Linear fitting was performed using the least squares method to obtain the coefficients between the pipe liquid pressure and the ultrasonic propagation time in step S700. k and c The value is then used to calculate the pressure of the liquid inside the pipe being tested.

2. The ultrasonic measurement method for liquid medium pressure in a pipeline according to claim 1, characterized in that, In step S200, the pipe wall thickness is calculated using the following formula: Where t1 is the time point when the first echo is received, and t2 is the time point when the second echo is received; C represents the sound velocity of the ultrasonic longitudinal wave in the pipe wall material.

3. The ultrasonic measurement method for liquid medium pressure in a pipeline according to claim 1, characterized in that, In step S500, the measuring device is installed on the test pipe, and the ultrasonic array transceiver is controlled to excite the ultrasonic array transducer to generate an ultrasonic longitudinal wave at a certain angle, which is converted into a transverse wave in the zero-stress test block. The transverse wave propagates through a polygon and is finally received by the ultrasonic array transducer. The ultrasonic array transceiver sends the received transverse wave echo data to the main control computer. The main control computer calculates the propagation time of the ultrasonic refracted transverse wave in the pipe wall through the autocorrelation algorithm and the temperature compensation algorithm.

4. The ultrasonic measurement method for liquid medium pressure in a pipeline according to claim 3, characterized in that, The temperature compensation algorithm steps are as follows: The propagation time of ultrasonic transverse waves within the pipe wall is linearly related to the temperature of the pipe wall. t=t'+r *D T in, r This is the temperature compensation coefficient; Δ T This refers to the difference between the temperature of the pipe being measured and the temperature during calibration, during actual measurement. t' The time it takes for the ultrasonic transverse wave to propagate through the tube wall is calculated using an autocorrelation algorithm during actual measurement.

5. The ultrasonic measurement method for liquid medium pressure in a pipeline according to claim 4, characterized in that, Within the set temperature range, 16 evenly distributed points on the pipe wall were selected as test points. The temperature of the constant temperature chamber was changed. After the temperature of the constant temperature chamber reached the set point, we continued to wait until the temperature of the pipe wall and the temperature inside the chamber were consistent. The propagation time of the ultrasonic transverse wave in the pipe wall was measured. By cyclically changing the temperature of the constant temperature chamber three times and recording the propagation time of the ultrasonic transverse wave at each temperature point, a linear relationship formula between the propagation time of the ultrasonic transverse wave in the pipe wall and the temperature of the pipe wall was obtained through fitting.

6. The ultrasonic measurement method for liquid medium pressure in a pipeline according to claim 1, characterized in that, The wall thickness of the pipe to be tested is greater than 2 mm.

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