Externally-attached multi-channel ultrasonic measurement device and method

Abstract

The invention discloses an externally-attached multi-channel ultrasonic measurement device and method, and relates to the technical field of ultrasonic gas flow measurement. The method comprises the following steps: performing ultrasonic echo signal measurement by using an externally-attached multi-channel ultrasonic measurement device, and performing pipeline section measurement, flow velocity detection and flow calculation according to the ultrasonic echo signal. The three core pain points of low probe positioning precision, poor installation efficiency and large flow calculation error in an existing externally-attached multi-channel ultrasonic flow measurement technology can be solved, meanwhile, the adaptability and reliability of a system to industrial complex working conditions are improved, and key technical support is provided for high-precision gas and liquid flow measurement.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic gas flow measurement technology, and in particular to an externally mounted multi-channel ultrasonic measuring device and method. Background Technology

[0002] Against the backdrop of continuous evolution of human society and rapid innovation in science and technology, gas flow rate, as one of the important metrological indicators in contemporary production and life, faces increasingly stringent requirements regarding its accuracy, stability, and reliability. Compared to other flow meters, ultrasonic gas flow meters offer a wider measurement range, higher measurement accuracy, and lower pressure loss, making them more widely applicable and widely used in industrial metrology.

[0003] However, existing ultrasonic flow measurement technology still suffers from three major pain points, severely restricting the development and application of ultrasonic gas flow meters: First, low probe positioning accuracy. Traditional external ultrasonic probe positioning relies heavily on manual marking, simple protractors, or fixed-size clamps, resulting in angular deviations, radial displacement deviations, and misalignment of symmetrical probe axes. This directly leads to ultrasonic propagation path deviations, causing time difference distortion in flow velocity calculations and ultimately amplifying flow measurement errors. Second, poor installation efficiency and insufficient versatility. Traditional probe installation requires cumbersome steps such as "pipe diameter measurement - marking - point-by-point fixing - manual calibration." Installing an 8-channel probe by a single person takes more than 30 minutes. Moreover, clamps are mostly designed for fixed pipe diameters, requiring multiple sets of clamps to be customized for different pipe specifications, resulting in high equipment inventory costs and poor flexibility in emergency deployment. Third, large flow calculation errors. Existing pipe cross-sectional area calculations are mostly based on the assumption that "the pipe is an ideal circle," failing to consider the ellipticity deviation and local wall thickness unevenness commonly found in industrial pipes. At the same time, the flow velocity measurement algorithm has poor adaptability to signal distortion, making it difficult to meet the requirements of high-precision measurement in terms of flow calculation accuracy. Therefore, developing a technical solution that combines high-precision positioning, efficient installation, and accurate flow calculation has significant engineering value and practical implications. Summary of the Invention

[0004] The purpose of this invention is to provide an externally attached multi-channel ultrasonic measurement device and method, which aims to solve or improve at least one of the above-mentioned technical problems.

[0005] To achieve the above objectives, the present invention provides the following solution: An externally mounted multi-channel ultrasonic measuring device includes: a clamp, multiple ultrasonic probes, and a measuring module connected to each of the ultrasonic probes; each ultrasonic probe is mounted on the outside of a pipe via the clamp; wherein the clamp is used to fix the ultrasonic probe; the ultrasonic probe is used to acquire ultrasonic echo signals; and the measuring module is used to perform pipe cross-section measurement, flow velocity detection, and flow rate calculation based on the ultrasonic echo signals.

[0006] Optionally, the clamp includes two arc-shaped beams, which are detachably connected to the outer wall of the pipe; an extension adjustment section is installed on the arc-shaped beam, and a silicone pad is installed at the extension end of the extension adjustment section; the outer side of the arc-shaped beam is engraved with an angle, and multiple T-shaped grooves are also provided on the arc-shaped beam; the T-shaped grooves are used for sliding connection with the probe holder; the probe holder is also provided with a knob lock for fixing the ultrasonic probe in a set position.

[0007] Optionally, the measurement module specifically includes: an ultrasonic connection harness, an ultrasonic transceiver and control module, a power supply module, a communication module, a data acquisition card, a USB connection cable, and a host computer; The ultrasonic connection harness is connected to each of the ultrasonic probes and the ultrasonic transceiver and control module respectively; the ultrasonic transceiver and control module is connected to the power supply module, the communication module and the data acquisition card respectively; the data acquisition card is connected to the host computer via the USB connection cable; the host computer is also connected to the communication module.

[0008] The present invention also provides an externally attached multi-channel ultrasonic measurement method, using the device described above, comprising: The system acquires ultrasonic echo signals and performs pipe cross-section measurement, flow velocity detection, and flow rate calculation based on these signals. The pipe cross-section measurement includes: cross-correlation calculation between a preset Gaussian echo signal and the actual acquired echo signal; extraction of the echo transit time using zero-crossing detection technology; and optimization of signal characteristics using power spectral analysis and spectral compression techniques to calculate the pipe wall thickness and inner diameter. The flow velocity detection includes: utilizing the statistical characteristics of each wave amplitude in the ultrasonic echo signal, setting a threshold range, locating signal feature points through zero-crossing detection, and calculating the ultrasonic propagation time difference to obtain the flow velocity. The flow rate calculation includes: calculating the target flow rate using the results of the pipe cross-section measurement and flow velocity detection.

[0009] Optionally, the pipe cross-section measurement specifically includes the following steps: A pre-defined single Gaussian echo signal y(t) is constructed and cross-correlated with the actual acquired ultrasonic echo signal x(t). The cross-correlation function R is calculated when the correlation between the two signals is maximized. xy When (t) reaches its maximum value, the range of echo propagation time can be preliminarily determined based on the peak position. To address the issue of distortion in the first main peak value after cross-correlation calculation, power spectrum analysis technology is introduced to extract effective frequency components and filter out interference frequency bands by calculating the power spectrum of discrete-time signals. After compressing the calculated spectral signal, it is restored to a cross-correlation signal in the time domain. The envelope is then plotted, and the pipe wall thickness and inner diameter are calculated based on the extreme points of the envelope.

[0010] Optionally, the flow rate detection specifically includes the following steps: By statistically analyzing the amplitude distribution pattern of ultrasonic echo signals, the amplitude ranges of the second Gaussian echo [V1, V2], the third Gaussian echo [V3, V4], and the fourth Gaussian echo [V5, V6] were determined. Based on the characteristic that "the maximum amplitude fluctuation of the previous wave does not exceed the minimum amplitude of the next wave," a low threshold range was set. The high threshold range is ; The zero-crossing position of a specific wave is detected by combining high and low thresholds. When the signal amplitude exceeds the high threshold, the zero-crossing point is used as a feature point to record the time. If the signal distortion causes the amplitude to fall below the high threshold, the zero-crossing point corresponding to the low threshold is used as the feature point. This ensures that the time difference can be stably extracted under different operating conditions, and then the fluid velocity can be calculated.

[0011] Optionally, the flow calculation includes the following steps: By combining the cross-sectional area S obtained from the pipe cross-section measurement algorithm and the weighted average flow velocity v obtained from the flow velocity measurement algorithm, the gas flow rate is calculated using the basic flow formula Q=S×v, where Q is the gas flow rate, S is the pipe cross-sectional area, and v is the weighted average flow velocity of the fluid in the pipe.

[0012] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects: This invention discloses an externally mounted multi-channel ultrasonic measuring device and method. The method includes measuring ultrasonic echo signals using the externally mounted multi-channel ultrasonic measuring device, and performing pipe cross-section measurement, flow velocity detection, and flow rate calculation based on the ultrasonic echo signals. This invention addresses the three core pain points of existing externally mounted multi-channel ultrasonic flow measurement technologies: low probe positioning accuracy, poor installation efficiency, and large flow rate calculation errors. It also improves the system's adaptability and reliability to complex industrial conditions, providing key technical support for high-precision gas and liquid flow rate measurement. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the ring clamp in this embodiment; Figure 2 This is a schematic diagram of the pipe cross-section model in this embodiment; Figure 3 This is a schematic diagram of the components of the multi-channel ultrasonic pipeline measurement system in this embodiment; Figure 4 This is a hardware logic block diagram of the multi-channel ultrasonic pipeline measurement system in this embodiment; Figure 5 This is a schematic diagram of the algorithm module for ultrasonic gas thickness measurement in this embodiment; Figure 6 This is a diagram showing the echo signal amplitude in this embodiment. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] The purpose of this invention is to provide an externally attached multi-channel ultrasonic measurement device and method, which aims to solve or improve at least one of the above-mentioned technical problems.

[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] like Figures 1-4 As shown, the present invention provides an externally mounted multi-channel ultrasonic measuring device, comprising: a clamp, multiple ultrasonic probes, and a measuring module connected to each of the ultrasonic probes; each ultrasonic probe is mounted on the outside of a pipe via the clamp; wherein, the clamp is used to fix the ultrasonic probe; the ultrasonic probe is used to acquire ultrasonic echo signals; the measuring module is used to perform pipe cross-section measurement, flow velocity detection, and flow rate calculation based on the ultrasonic echo signals.

[0019] (I) Fixture Structure Design The fixture adopts a three-layer structure of "ring support frame + modular probe holder + quick locking mechanism". The entire material is made of lightweight, high-strength aluminum alloy with anodized surface treatment for rust prevention. The total weight is ≤1.5kg (DN200 specification). The specific structure is as follows: 1. Circular support frame Main structure: It consists of two semi-circular arc beams connected by hinges. T-shaped grooves (12mm wide and 8mm deep) are opened on the inner side of the arc beams for sliding adjustment of the probe holder; Pipe diameter adaptation: The curved beam is equipped with expansion joints at both ends (adjustment range 20mm-50mm), which can be locked with bolts to adapt to DN25 (inner diameter 25mm)-DN200 (inner diameter 200mm) pipes; Positioning reference: The outer side of the curved beam is engraved with angle graduations (0°-180°, accuracy 0.5°), and the inner side is pasted with a 3mm thick silicone pad (Shore hardness 50°), which ensures pipe fit while avoiding scratches on the pipe wall. The curved beam is a semi-circular curved beam, and the two semi-circular curved beams are connected by hinges. The two semi-circular curved beams are installed on the outer wall of the pipe using cam-type quick clamps.

[0020] 2. Modular probe holder It is divided into two types: thickness probe holder and speed probe holder. Both adopt a detachable design, and the position adjustment and quick assembly / disassembly are achieved by the cooperation of T-shaped slider and annular frame groove.

[0021] 3. Quick-locking mechanism Ring frame locking: Cam-type quick clamps (model GH-101) are symmetrically arranged at the connection of the two arc beams. Pressing the clamps can quickly clamp the frame and the pipe. The clamping force is adjustable. Probe holder locking: Each holder is equipped with an M5 rotary lock. After tightening, the position is locked by the friction between the slider and the slide groove. After loosening, it can slide and adjust along the slide groove.

[0022] 4. Installation and positioning process Taking a DN100 stainless steel pipe as an example, the complete installation process is as follows: Frame pre-assembly: Open the two semi-circular arc beams and place them on the pipe to be measured. Adjust the telescopic section to make the silicone pad fit against the pipe wall. Fasten the cam clamp to complete the frame fixation, which takes about 30 seconds. Thickness probe installation: Take 8 thickness measurement probe holders, install 5MHz probes into each one, and apply coupling agent until the reservoir is full; Slide the card holder along the groove of the annular frame, position it according to the angle scale (0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°), tighten the knob lock to fix it, which takes about 1 minute; Speed ​​probe installation: Take 8 pairs of speed measuring probe holders, install 2 0.1MHz probes in each pair, and adjust the rotating shaft so that the included angle is 30°; Align the probes with the pipe axis, slide the mounting bracket along the groove to ensure that the spacing between the pairs of probes is consistent with the design value (e.g., the spacing of DN100 pipe is set to 220mm), tighten the knob to lock it in place, which takes about 1 minute. Calibration check: Use a laser rangefinder (accuracy ±0.1mm) to check the probe spacing and angle to ensure that they meet the measurement requirements. This takes about 30 seconds.

[0023] (ii) Measurement Module This solution can be directly integrated into an external multi-channel ultrasonic flow meter, and its core hardware modules include: Communication module: Primarily maintains communication between the host computer and the hardware system via a communication protocol. It sends commands to the communication module via the RS485 protocol and transmits data acquired by the high-speed USB protocol acquisition card to the host computer. The communication module acts as a bridge between the host computer and the hardware system.

[0024] Power supply module: This module is mainly responsible for supplying power to the entire system. In addition to powering the system, it can also detect changes in voltage and current of the hardware. When conditions are unfavorable to the circuit board, it will make timely adjustments to ensure circuit safety and improve circuit stability and reliability.

[0025] Control module: This is the control center of the entire hardware, controlling the transmission and reception of ultrasonic signals from the probe and monitoring the working status of the entire hardware system.

[0026] Data acquisition module: This module mainly acquires the transmitted and received ultrasonic signals through the acquisition card, converts analog signals into digital signals, and allows us to acquire ultrasonic signals in real time and transmit them to the host computer for analysis and processing.

[0027] (III) Flow Calculation Algorithm Module The pipeline flow rate calculation algorithm adopts a three-level architecture of "precise measurement of cross-sectional features + stable flow velocity detection + integrated flow rate calculation". Through algorithm fusion, it improves anti-interference capability and calculation accuracy. Specifically, it includes three parts: a pipeline cross-sectional feature measurement algorithm, a flow velocity measurement algorithm, and a flow rate calculation model (e.g., ...). Figure 5 (as shown) 1. Pipe Cross-Section Feature Measurement Algorithm An adaptive Gaussian echo cross-correlation algorithm is used to accurately calculate the pipe wall thickness and inner diameter. The core logic involves cross-correlation calculations between a preset Gaussian echo signal and the actual acquired echo signal, combined with zero-crossing detection technology to extract the echo transit time, and then using power spectral analysis and spectrum compression techniques to optimize signal characteristics and improve the accuracy of time difference measurement. The specific steps are as follows: Coarse localization via cross-correlation: A preset single Gaussian echo signal y(t) is constructed and cross-correlated with the actual acquired ultrasonic echo signal x(t). The cross-correlation function Rt is then used to determine the localization. xy The peak position of (t) preliminarily determines the echo arrival time. The cross-correlation calculation formula is as follows: In the formula, x(t) is the actual echo signal, y(t) is the preset Gaussian echo signal, and R xy (t) is the cross-correlation function. R represents the time shift of the preset single Gaussian echo signal y(t) relative to the actually acquired ultrasonic echo signal x(t), i.e., the "misalignment interval" between the two signals on the time axis. When the correlation between the two is at its maximum, R... xyWhen (t) reaches its maximum value, the range of echo propagation time can be preliminarily determined by combining the peak position.

[0028] Power Spectrum Optimization and Spectrum Compression: To address the issue of distortion in the first dominant peak after cross-correlation calculations, power spectrum analysis techniques are introduced. Effective frequency components are extracted through discrete-time signal power spectrum calculation, filtering out interference frequency bands. The discrete-time signal power spectrum calculation is shown in the following equation: In the formula, N represents the length of the discrete signal. Let represent the frequency at the k-th frequency point, and Δt represent the sampling period. Using 5MHz as the center frequency, frequency domain extraction and downsampling of the power spectrum are performed to concentrate the spectrum range to the target frequency band, enhancing the time difference information characteristics.

[0029] Wall thickness and inner diameter calculation: After compressing the calculated spectral signal, restore it to the cross-correlation signal in the time domain, plot the envelope, and find the extreme points. The location of the maximum extreme point is at the initial arrival time t of the first major multiple Gaussian echo signal. max Take the times of the three extreme points to its left, t1, t2, and t3, and calculate the thickness using the following formula: In the formula, d s Vt is the measured pipe wall thickness, v1 is the speed at which the ultrasonic wave propagates within the pipe wall, t is the time difference obtained by subtracting the intervals, and NE is the spectral compression ratio. Spectral compression technology can improve the resolution of the time difference and, to some extent, accommodate the distortion of the time-domain signal.

[0030] The pipe diameter is primarily calculated using the time difference between the first primary multiple Gaussian echo and the second and third Gaussian echoes. Similarly, the envelope of the cross-correlation peaks is plotted to determine the extreme points of the envelope. The arrival time of the first primary multiple Gaussian echo... t max To the left of the envelope, find another maximum point. t m1 Find another maximum point of the envelope between them. t m2 The formula for calculating pipe diameter is as follows: In the formula, d 1 represents the pipe diameter calculated based on the time difference between the first primary multiple Gaussian echo and the third Gaussian echo. d2 represents the pipe diameter calculated based on the time difference between the first primary multiple Gaussian echo and the second Gaussian echo. In actual measurement, the amplitude of the second primary Gaussian echo is usually smaller than that of the third primary Gaussian echo, and the stability of the waveform is easily affected by the probe on the opposite side. Therefore, this embodiment introduces a weighted average model to optimize the pipe diameter determined by the two time differences.

[0031] Finally, the pipe cross-sectional area S is calculated based on the inner diameter: S = π·(d / 2) 2 .

[0032] 2. Flow velocity measurement algorithm A dual-threshold algorithm based on zero-crossing detection is used to process the denoised ultrasonic signal. By setting two thresholds (high and low), signal distortion can be effectively identified, improving the stability of flow velocity measurement. The core principle is to utilize the statistical characteristics of the amplitude values ​​of each wave in the ultrasonic echo signal, set an appropriate threshold range, locate signal feature points through zero-crossing detection, and calculate the ultrasonic propagation time difference to obtain the flow velocity. The specific implementation is as follows: Threshold range determination: By statistically analyzing the amplitude distribution pattern of the echo signal, the amplitude ranges of the second wave [V1, V2], the third wave [V3, V4], and the fourth wave [V5, V6] are determined. Based on the characteristic that "the maximum amplitude fluctuation of the previous wave does not exceed the minimum amplitude of the next wave", the echo signal amplitude diagram is as follows. Figure 6 As shown.

[0033] Set a low threshold range: .

[0034] The range of the high threshold Uh should satisfy: .

[0035] Dual threshold detection: The zero-crossing position of a specific wave is detected by combining high and low thresholds. When the signal amplitude exceeds the high threshold, the zero-crossing point is used as a feature point to record the time. If the signal distortion causes the amplitude to fall below the high threshold, the zero-crossing point corresponding to the low threshold is used as the feature point. This ensures that the time difference can be stably extracted under different operating conditions, and then the fluid velocity can be calculated.

[0036] 3. Flow Calculation Model By combining the cross-sectional area S obtained from the pipe cross-sectional feature measurement algorithm and the weighted average flow velocity v obtained from the flow velocity measurement algorithm, the gas flow rate is calculated using the basic flow formula Q=S×v, where Q is the gas flow rate, S is the pipe cross-sectional area, and v is the weighted average flow velocity of the fluid inside the pipe. This model ensures the accuracy of flow rate calculation through precise input of basic parameters.

[0037] Based on the above technical solution, the following embodiments are provided.

[0038] Example 1: Real-time measurement of natural gas flow in a DN100 stainless steel pipeline In the scenario of measuring the natural gas flow rate in a DN100 stainless steel pipeline, the measurement should be completed according to the following procedure: Eight self-emitting and self-receiving ultrasonic thickness measurement probes with a center frequency of 5MHz and a diameter of 10mm were selected and uniformly attached to the outer wall of the pipe at a 45° interval. A high-temperature coupling agent was used to achieve adhesion to the pipe wall. A multi-channel ultrasonic excitation module was connected and set to an excitation voltage of 70V. Eight pairs of piezoelectric ceramic ultrasonic velocimetry probes with a center frequency of 0.1MHz were used and attached to the upstream and downstream sides of the pipe in a cross-layout configuration. The probe spacing was set to 220mm and the angle with the pipe axis was 30°. An adjustable gain (0-60dB) receiving module was connected. An ARTUSB8582 high-speed data acquisition card was connected, communicating with the host computer via the USB 3.0 protocol. Remote parameter control of the hardware by the host computer was achieved through an RS485 serial port.

[0039] The pipe wall thickness and outer diameter were measured using a micrometer with an accuracy of 0.001 mm. The data was then input into the host computer to correct the propagation speed parameters of ultrasonic waves in stainless steel. A standard gas flow generator was connected to output a known flow velocity of 5-40 m / s. The echo signal was collected to optimize the threshold parameters of the dual-threshold zero-crossing detection algorithm, ensuring that the transit time and flow velocity measurement errors met the standards.

[0040] After the system is started, the thickness measurement module acquires echo signals from eight probes using an adaptive Gaussian echo cross-correlation-zero-crossing detection algorithm, locates the echo oscillation period, extracts feature points, and calculates the wall thickness, diameter, and cross-sectional area based on the propagation velocity. The velocity measurement module simultaneously acquires downstream / counter-current echo signals, performs wavelet transform noise reduction, calculates the transit time using dual-threshold zero-crossing detection, and calculates the flow velocity of each channel based on the ultrasonic propagation velocity in the gas (compensated for on-site temperature and pressure). Weights are assigned according to the measurement error of each channel, and a weighted average is used to obtain the average flow velocity of the entire cross-section. This average velocity is then substituted into the flow rate formula (compensated for temperature and pressure) to calculate the volumetric flow rate. The host computer displays cross-sectional parameters, flow velocity of each channel, average flow velocity and cumulative flow in real time, generates flow field distribution map and velocity vector map, and simultaneously completes data storage and remote upload to the monitoring platform.

[0041] Example 2: Industrial Nitrogen Flow Measurement for DN25 Acrylic Pipe The experimental procedure for measuring industrial nitrogen flow in a DN25 acrylic pipe is as follows: Four miniature thickness probes with a diameter of 6mm and a center frequency of 5MHz were selected and attached to the outer wall of the pipe at a 90° interval. A low-viscosity coupling agent was used and a heat insulation sleeve was added to avoid the influence of temperature fluctuations. Four pairs of miniature velocity probes with a diameter of 10×10mm (center frequency of 0.1MHz) were used, with a probe spacing of 60mm and an angle of 45° with the pipe axis. The gain of the receiving module was adjusted to 50dB to enhance weak echoes. A polytetrafluoroethylene protective film was added to the probe surface to prevent oil contamination, and a 50Hz power frequency filter circuit was added to the data acquisition card to reduce electromagnetic interference.

[0042] The true value of the pipe's outer diameter is measured using a laser diameter gauge, and the true value of the wall thickness is measured using a micrometer. The sound velocity parameter of the acrylic material in the algorithm is calibrated to ensure that the measurement error of the cross-sectional parameters meets the standard. A nitrogen flow rate of 2-15 m / s is output through a small standard flow device, and the threshold of the dual-threshold zero-crossing detection algorithm is adjusted to ensure that the transit time and flow velocity measurement error meet the requirements.

[0043] The thickness measurement module processes the echo signal using an adaptive Gaussian echo cross-correlation-zero-crossing detection algorithm, and improves the time difference resolution with the help of spectrum compression technology to calculate the wall thickness, diameter, and cross-sectional area. The acquired echo signal is subjected to wavelet noise reduction and dual threshold detection to obtain the downstream / countercurrent transit time. Combined with the sound velocity in nitrogen after temperature and pressure compensation, the flow velocity of each channel is calculated. The average flow velocity is obtained by weighting according to the error allocation weight. The average flow velocity is substituted into the flow rate formula (temperature and pressure compensation) to obtain the industrial nitrogen volumetric flow rate.

[0044] The thickness measurement sound velocity parameters and velocity measurement algorithm thresholds are calibrated monthly. When slight corrosion occurs in the pipeline, the system can identify changes in cross-sectional area in real time and automatically correct the flow calculation results.

[0045] In summary, the specific effects of this invention are as follows: (i) Positioning accuracy is significantly improved, reducing measurement errors at the source. Optimization of angle and position positioning accuracy The 0.5° precision angle scale of the annular support frame, combined with the T-shaped sliding groove and the detachable and adjustable design of the modular mounting base, reduces the probe angle positioning error and improves the position adjustment accuracy. Compared with traditional manual marking positioning, the ultrasonic propagation path offset is greatly reduced, effectively avoiding the distortion of flow velocity calculation time difference caused by path deviation. In the actual measurement of DN100 stainless steel pipe, the actual deviation of the eight thickness measuring probes positioned at preset angles (0°, 45°, etc.) was controlled within ±0.3°, laying the foundation for accurate calculation of the subsequent cross-sectional area.

[0046] Enhanced consistency in symmetrical probe cooperative positioning By using the guide groove of the fixture and the scale reference, the spacing deviation of the paired velocity probes is controlled within ±0.5mm, and the overlap of the symmetrical probe axes is ≤0.5mm, thus solving the "false time difference" problem caused by the misalignment of symmetrical paths in traditional installations. Experimental data shows that after optimizing the positioning consistency of the symmetrical probes, the dispersion of multi-channel velocity measurement data is reduced, significantly improving the reliability of flow velocity measurement.

[0047] (ii) The installation process has been greatly simplified and the time required has been significantly reduced. Employing a dual locking design of cam-type quick clamps and knob locks, coupled with a modular mounting structure for rapid assembly and disassembly, a single person can complete the entire installation process of an 8-channel thickness probe and 8 pairs of speed probes in just about 3 minutes, improving efficiency by 90% compared to traditional installation methods (which take over 30 minutes). In industrial field testing, the deployment time per point has been reduced from the traditional 15 minutes to 2 minutes, significantly reducing labor costs and project time pressure.

[0048] (iii) Optimization of cross-sectional area calculation accuracy to support the accuracy of flow measurement Improved accuracy of transit time measurement The adaptive Gaussian echo cross-correlation algorithm combined with spectrum compression technology significantly reduces the measurement error of pipe wall thickness; by using 8-channel multi-angle measurement and weighted average model fitting of cross-sectional area, the influence of pipe ellipticity and uneven wall thickness is fully avoided, thus improving the accuracy of cross-sectional area calculation.

[0049] Enhanced stability of flow velocity measurement: The dual-threshold algorithm based on zero-crossing detection can effectively identify signal distortion and has significantly better adaptability to low flow velocity (≤1m / s) scenarios than the traditional single-threshold method, ensuring measurement stability under different flow conditions.

[0050] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0051] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. An externally mounted multi-channel ultrasonic measuring device, characterized in that, include: The system includes a clamp, multiple ultrasonic probes, and a measurement module connected to each of the ultrasonic probes; each ultrasonic probe is mounted on the outside of the pipe via the clamp; wherein the clamp is used to fix the ultrasonic probe; the ultrasonic probe is used to acquire ultrasonic echo signals; and the measurement module is used to perform pipe cross-section measurement, flow velocity detection, and flow rate calculation based on the ultrasonic echo signals.

2. The externally attached multi-channel ultrasonic measuring device according to claim 1, characterized in that, The clamp includes two arc-shaped beams, which are detachably connected to the outer wall of the pipe. An adjustable telescopic section is installed on each arc-shaped beam, and a silicone pad is installed at the telescopic end of the adjustable telescopic section. An angle is engraved on the outer side of each arc-shaped beam, and multiple T-shaped grooves are also provided on the arc-shaped beam. The T-shaped grooves are used for sliding connection with the probe holder. A knob lock is also provided on the probe holder for fixing the ultrasonic probe in a set position.

3. The externally attached multi-channel ultrasonic measuring device according to claim 1, characterized in that, The measurement module specifically includes: an ultrasonic connection harness, an ultrasonic transceiver and control module, a power supply module, a communication module, a data acquisition card, a USB connection cable, and a host computer; The ultrasonic connection harness is connected to each of the ultrasonic probes and the ultrasonic transceiver and control module respectively; the ultrasonic transceiver and control module is connected to the power supply module, the communication module and the data acquisition card respectively; the data acquisition card is connected to the host computer via the USB connection cable; the host computer is also connected to the communication module.

4. An externally attached multi-channel ultrasonic measurement method, using the device as described in any one of claims 1-3, characterized in that, include: The system acquires ultrasonic echo signals and performs pipe cross-section measurement, flow velocity detection, and flow rate calculation based on these signals. The pipe cross-section measurement includes: cross-correlation calculation between a preset Gaussian echo signal and the actual acquired echo signal; extraction of the echo transit time using zero-crossing detection technology; and optimization of signal characteristics using power spectral analysis and spectral compression techniques to calculate the pipe wall thickness and inner diameter. The flow velocity detection includes: utilizing the statistical characteristics of each wave amplitude in the ultrasonic echo signal, setting a threshold range, locating signal feature points through zero-crossing detection, and calculating the ultrasonic propagation time difference to obtain the flow velocity. The flow rate calculation includes: calculating the target flow rate using the results of the pipe cross-section measurement and flow velocity detection.

5. The externally attached multi-channel ultrasonic measurement method according to claim 4, characterized in that, The specific steps for measuring the pipe cross-section include: A pre-defined single Gaussian echo signal y(t) is constructed and cross-correlated with the actual acquired ultrasonic echo signal x(t). The cross-correlation function R is calculated when the correlation between the two signals is maximized. xy When (t) reaches its maximum value, the range of echo propagation time can be preliminarily determined based on the peak position. To address the issue of distortion in the first main peak value after cross-correlation calculation, power spectrum analysis technology is introduced to extract effective frequency components and filter out interference frequency bands by calculating the power spectrum of discrete-time signals. After compressing the calculated spectral signal, it is restored to a cross-correlation signal in the time domain. The envelope is then plotted, and the pipe wall thickness and inner diameter are calculated based on the extreme points of the envelope.

6. The externally attached multi-channel ultrasonic measurement method according to claim 4, characterized in that, The flow rate detection specifically includes the following steps: By statistically analyzing the amplitude distribution pattern of ultrasonic echo signals, the amplitude ranges of the second Gaussian echo [V1, V2], the third Gaussian echo [V3, V4], and the fourth Gaussian echo [V5, V6] were determined. Based on the characteristic that "the maximum amplitude fluctuation of the previous wave does not exceed the minimum amplitude of the next wave," a low threshold range was set. The high threshold range is ; The zero-crossing position of a specific wave is detected by combining high and low thresholds. When the signal amplitude exceeds the high threshold, the zero-crossing point is used as a feature point to record the time. If the signal distortion causes the amplitude to fall below the high threshold, the zero-crossing point corresponding to the low threshold is used as the feature point. This ensures that the time difference can be stably extracted under different operating conditions, and then the fluid velocity can be calculated.

7. The externally attached multi-channel ultrasonic measurement method according to claim 4, characterized in that, The flow calculation specifically includes the following steps: By combining the cross-sectional area S obtained from the pipe cross-section measurement algorithm and the weighted average flow velocity v obtained from the flow velocity measurement algorithm, the gas flow rate is calculated using the basic flow formula Q=S×v, where Q is the gas flow rate, S is the pipe cross-sectional area, and v is the weighted average flow velocity of the fluid in the pipe.

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