Multichannel gas ultrasonic flowmeter

Abstract

The invention provides a multichannel gas ultrasonic flowmeter, which relates to the technical field of flow measurement and comprises a hardware layer and a software layer, the hardware layer comprises a pipeline, a connecting mechanism, a multichannel ultrasonic transducer, a pressure sensor, a temperature sensor, a wiring terminal box and a control box with an LCD display screen; the software layer comprises a data acquisition module, a preprocessing module, a multichannel speed measurement module, a data fusion module, a dynamic parameter compensation module, a flow calculation module, a man-machine interaction module, a communication module and a storage module. Pipeline section flow velocity information is collected through a multichannel ultrasonic transducer array, and a complex flow state is fitted in combination with a weighted fusion algorithm; the flow is dynamically compensated and corrected based on pressure and temperature; reliable operation of the system is guaranteed by means of hardware redundancy and a software verification diagnosis mechanism, the problems that a traditional flowmeter is low in measurement precision and poor in working condition adaptability are solved, and high-precision and stable gas flow measurement is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of flow measurement, and in particular to a multi-channel gas ultrasonic flowmeter. Background Art

[0002] In the measurement of gases like natural gas and industrial waste gas, ultrasonic flowmeters have become a key alternative to traditional mechanical flowmeters thanks to their non-contact measurement, minimal pressure drop (1 / 5-1 / 10 of that of mechanical flowmeters), and wide range ratios (reaching over 1:100). Their measurement principle involves transmitting and receiving sound waves via an ultrasonic transducer. The effect of gas flow on the propagation velocity of the sound waves (increasing with the flow and decreasing with the flow) is used to calculate the flow velocity, and thus the flow rate.

[0003] During use, an existing multi-channel gas ultrasonic flowmeter is widely used due to its advantages such as non-contact measurement, low pressure loss, and wide range ratio. Its core principle is to calculate the flow rate by detecting the propagation time difference of the sound wave in the downstream / reverse flow direction through an ultrasonic transducer. However, there are two key problems in the software system in the existing technology: first, the processing of multi-channel ultrasonic data only uses single-point averaging, and does not consider the impact of uneven flow velocity distribution in the pipeline, resulting in insufficient measurement accuracy under low flow rate conditions; second, there is a lack of real-time dynamic pressure and temperature parameter compensation mechanism. When the working conditions fluctuate, the relationship between sound velocity and gas volume cannot be corrected, further amplifying the measurement error. Therefore, there is an urgent need to provide a multi-channel gas ultrasonic flowmeter to solve the above technical problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a multi-channel gas ultrasonic flowmeter, which, through the collaborative design of the hardware layer and the software layer, can achieve high-precision and stable measurement of gas flow, effectively solve the measurement problems under complex flow fields, and improve the reliability and adaptability of the measurement system.

[0005] To solve the above technical problems, the present invention provides a multi-channel gas ultrasonic flowmeter, which includes a hardware layer and a software layer, and the two layers work together to realize the multi-channel speed measurement and dynamic parameter compensation functions; The hardware layer includes a pipeline, and a connecting mechanism is fixedly connected at both ends of the pipeline. The connecting mechanism includes flanges at both ends of the pipeline, and connecting holes are equidistantly opened in a ring on the flange. A sealing groove is opened on the inner side of the connecting hole, and a sealing ring can be installed in the sealing groove; a detection mechanism is relatively installed on both sides of the pipeline, and the detection mechanism includes a mounting tube fixedly connected to both sides of the pipeline, and the mounting tubes have the same length in the same vertical direction. The mounting tubes are threadedly connected to an anti-drop cap at one end away from the pipeline, and an ultrasonic transducer is installed at the end located in the pipeline, and the ultrasonic transducer wire is connected to the terminal box through a guide tube; an auxiliary detection mechanism is installed at the upper end of the pipeline, including a pressure sensor and a temperature sensor in the detection holes at both ends above the pipeline; a terminal box with a terminal and a sealing structure is fixed on the pipeline, and the terminal box is connected to the pressure sensor and the temperature sensor through wires, and a control mechanism is fixed on the upper end of the pipeline, and the control mechanism includes a fixing tube and a control box at the other end, and the control box is equipped with an LCD display and buttons; The software layer runs on the control mechanism, including a data acquisition module, which collects the ultrasonic transducer time signal, pressure and temperature data and packages them for transmission; a data preprocessing module that performs noise reduction verification on the data and then transmits it; a multi-channel speed measurement module that calculates the local flow velocity of each channel; a data fusion module that performs weighted fusion to obtain the average flow velocity; a dynamic parameter compensation module that calculates the correction coefficient based on pressure and temperature to compensate for the flow velocity; a flow calculation module that obtains the standard flow; a human-computer interaction module that realizes display and parameter configuration; a communication module that uploads data and receives instructions; and a storage module that stores historical data and parameters.

[0006] As a preferred method, the ultrasonic transducer time signal, pressure and temperature data are collected and packaged for transmission: Receive the downstream / reverse flow propagation time signals of several groups of ultrasonic transducers through the drive interface connected to the terminal box, and record the channel number; Collect real-time pressure data from the pressure sensor and real-time temperature data from the temperature sensor, and synchronously mark the collection timestamp; The collected raw data is packaged into a frame format and transmitted to the data preprocessing module; the frame format includes the channel number, time difference, pressure value, temperature value, and timestamp.

[0007] As a preference, the data pre-processing module performs noise reduction verification on the data and then transmits it in batches: The wavelet threshold noise reduction algorithm is used on the ultrasonic time difference signal to filter out the high-frequency noise introduced by electromagnetic interference and pipeline vibration; Use sliding average filtering on pressure and temperature data to eliminate instantaneous fluctuation noise; Invalid data is eliminated through validity check rules, and invalid data is supplemented by the weighted average of the valid data of the previous set number of times; The preprocessed data is transmitted to the multi-channel speed measurement module and the dynamic parameter compensation module.

[0008] Preferably, the channel velocity measurement module calculates the local flow velocity of each channel as follows: Obtain pre-processed ultrasonic data, identify the ultrasonic propagation path length of any channel, identify the time difference between the downstream and upstream propagation time signals of the channel, and identify the downstream propagation time and the upstream propagation time; The local flow velocity of each channel is calculated according to the preset formula; the local flow velocity of each channel is traversed, the channel number is marked and transmitted to the data fusion module.

[0009] In this application, the data fusion module performs weighted fusion to obtain the average flow rate, specifically: Obtain the position weight of each sound channel on the pipe cross section; calculate the average flow velocity using the weighted average algorithm; Perform consistency check on the local flow velocity and average flow velocity of each channel: If the deviation between the local flow velocity and the average flow velocity is greater than the deviation threshold, a position weight adjustment instruction for the channel is generated; the position weight adjustment instruction is used to adjust the position weight; after the position weight is adjusted, the weighted average algorithm is re-adopted for calculation; the average flow velocity is transmitted to the flow calculation module.

[0010] As a preference, the position weight of each channel on the pipe cross section is The acquisition logic is: Number-law velocity distribution model based on pipe cross section: ,in is the flow velocity at a distance r from the center of the pipe, is the maximum flow velocity at the center of the pipe, R is the pipe radius, is the equivalent radius of the ultrasonic transducer installation position, and the pipe cross section is divided into N flow velocity characteristic areas corresponding to the sound channel one by one; Calculate the theoretical flow rate integral ratio of each area as the initial position weight; When the flowmeter is installed and debugged, a calibration gas with a uniform flow rate is introduced to collect the actual local flow rate measured in each channel; Calculate the variance of the actual flow velocity distribution; set the allowable flow velocity distribution variance threshold. If the variance is greater than the flow velocity distribution variance threshold, use the correction coefficient to correct the initial position weight, and finally obtain the initial position of each channel.

[0011] Preferably, the position weight adjustment instruction is used to adjust the position weight, and the specific process is as follows: Obtain the position weight of the channel corresponding to the position weight adjustment instruction, record it as, identify the local flow velocity of the channel, calculate the deviation between the local flow velocity and the average flow velocity of the channel, and adjust the amplitude according to the deviation; After adjusting the weight of a single channel, the weights of the remaining channels are rebalanced to complete the dynamic adjustment of the position weights.

[0012] Preferably, the dynamic parameter compensation module calculates a correction coefficient to compensate for the flow rate based on pressure and temperature, specifically: Receive pre-processed pressure data and temperature data, and convert them into absolute pressure and absolute temperature; The sonic correction coefficient is derived based on the ideal gas state equation; The correction coefficient is used to dynamically compensate the average flow velocity, and the compensated flow velocity is transmitted to the flow calculation module.

[0013] Preferably, the flow calculation module obtains the standard flow, specifically: Calculate the gas flow rate under standard conditions based on the compensated flow rate, identify the pipe cross-sectional area, and calculate the volume flow rate. The pipe cross-sectional area is calculated based on the pipe inner diameter; The flow data is smoothed in real time to output a stable flow value. The exponential smoothing method is used. The specific process is as follows: When the flow meter is first started or calibrated, the first several raw flow data are collected and the initial smoothing value is calculated as a benchmark. The initial smoothing value is used as the starting input for subsequent exponential smoothing iterations. When the flow meter is operating normally, it collects the original flow data at the current moment in real time and iteratively calculates the smoothed flow value based on the exponential smoothing formula; If the current raw flow data exceeds the preset range, it is directly judged as abnormal data, the current exponential smoothing calculation is skipped, and the smoothed value of the previous moment is retained as the output; If abnormal traffic data is collected several times in succession, a traffic anomaly alarm is triggered, which is prompted through the human-computer interaction module and the smoothing iteration is automatically reset. The initial smoothing value is recalculated using the initial valid historical data and the normal iteration process is restored.

[0014] As an example, the human-computer interaction module realizes display and parameter configuration, specifically: Receive the results of the flow calculation module and display the current flow, flow rate of each channel, pressure, temperature and compensation coefficient in real time on the LCD screen; Respond to key input commands, support parameter configuration, and store the configuration parameters in the storage module; When the data exceeds the limit, an alarm will be triggered on the display screen.

[0015] As a preference, the communication module uploads data and receives instructions, specifically: Through the communication interface of the terminal box, which supports RS485 / Modbus protocol, real-time flow, pressure, temperature, channel status and other data can be uploaded to the external control system in a preset format; Receive control instructions from external devices, parse them, transmit them to the corresponding module for execution, and return the execution results.

[0016] Compared with related technologies, the multi-channel gas ultrasonic flowmeter provided by the present invention has the following beneficial effects: 1. This invention uses a multi-channel ultrasonic transducer array layout to synchronously collect flow velocity information in different areas of the pipeline cross-section. Combined with a weighted fusion algorithm based on the velocity distribution model, it accurately fits complex flow states such as laminar flow and turbulent flow. A dynamic weight adjustment mechanism eliminates abnormal data interference, breaking through the traditional single-channel measurement's reliance on flow field uniformity, comprehensively reflecting the true flow velocity distribution in the pipeline, and significantly reducing measurement errors caused by flow field distortion.

[0017] 2. The present invention integrates a real-time pressure and temperature monitoring module, constructs a dynamic compensation model based on the ideal gas state equation, and corrects the impact of pressure fluctuations and temperature drift on sound velocity and flow conversion in real time. The flow data is filtered in real time through an exponential smoothing algorithm, effectively eliminating instantaneous fluctuation interference and maintaining long-term stability of the measurement results under changing operating conditions.

[0018] 3. A redundant multi-channel ultrasonic transducer layout is adopted at the hardware level. When a single / multi-channel fails, the remaining channels can reconstruct the flow field data through algorithms. The software level uses the data preprocessing module to eliminate invalid data through validity verification rules and use historical valid data to complete the data. The flow calculation module triggers an alarm when continuously collecting abnormal data and automatically resets the smooth iteration. In scenarios with sensor drift and equipment aging, it can still maintain flow measurement accuracy, reduce the impact of system failures on industrial processes, and ensure the long-term reliable operation of the metering system.

[0019] In summary, the present invention breaks through the traditional measurement's reliance on flow field uniformity through a multi-channel ultrasonic transducer array layout and a weighted fusion algorithm, capturing the true flow velocity distribution under complex flow states; combining pressure and temperature dynamic compensation and flow smoothing processing mechanisms to ensure the long-term stability of measurement results under variable working conditions; relying on hardware redundancy design and software verification, diagnosis, and automatic reset functions, it can maintain measurement accuracy and realize fault alarms and data tracing when some equipment is abnormal, comprehensively improving the accuracy of gas flow measurement, adaptability to working conditions, and long-term system operation reliability, providing a stable and efficient solution for industrial gas metering scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A three-dimensional diagram of the hardware layer components of a multi-channel gas ultrasonic flowmeter provided by the present invention; Figure 2 for Figure 1 A perspective view of the other side is shown; Figure 3 for Figure 1 Bottom view shown; Figure 4 for Figure 1The side cross-sectional view shown; Figure 5 This is a connection relationship diagram of the software layer modules of the multi-channel gas ultrasonic flowmeter provided by the present invention.

[0021] Numbers in the figure: 1. Flange; 2. Sealing groove; 3. Connection hole; 4. Pipe; 5. Mounting tube; 6. Anti-drop cap; 7. Guide tube; 8. Pressure sensor; 9. Terminal box; 10. Control box; 11. Temperature sensor; 12. Ultrasonic transducer. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. As used in this disclosure and the appended claims, the singular forms "group," "class," and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0024] It should be understood that although the terms first, second, third, etc. may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining."

[0025] Please refer to Figure 1-Figure 5 A multi-channel gas ultrasonic flowmeter, comprising a hardware layer and a software layer, which work together to achieve multi-channel velocity measurement and dynamic parameter compensation functions; The hardware layer includes a pipeline 4, and a connecting mechanism is fixedly connected at both ends of the pipeline 4. The connecting mechanism includes flanges 1 at both ends of the pipeline 4, and connecting holes 3 are equidistantly opened in a ring on the flange 1. A sealing groove 2 is opened on the inner side of the connecting hole 3, and a sealing ring can be installed in the sealing groove 2; a detection mechanism is relatively installed on both sides of the pipeline 4, and the detection mechanism includes a mounting tube 5 fixed on both sides of the pipeline 4. The mounting tube 5 has the same length in the same vertical direction, and is threadedly connected to an anti-drop cap 6 at one end away from the pipeline 4. An ultrasonic transducer 12 is installed at one end located in the pipeline 4, and the ultrasonic transducer 12 wire is connected to the terminal box 9 through a guide tube 7; an auxiliary detection mechanism is installed at the upper end of the pipeline 4, including a pressure sensor 8 and a temperature sensor 11 in the detection holes at both ends above the pipeline 4; a terminal box 9 with a terminal and a sealing structure is fixed on the pipeline 4, and the terminal box 9 is connected to the pressure sensor 8 and the temperature sensor 11 through a wire, and a control mechanism is fixed on its upper end, and the control mechanism includes a fixing tube and a control box 10 at the other end, and the control box 10 is equipped with an LCD display and buttons; The software layer runs on the control mechanism, including a data acquisition module, which collects the time signal, pressure and temperature data of the ultrasonic transducer 12 and packages them for transmission; a data preprocessing module that performs noise reduction verification on the data and then transmits it separately; a multi-channel speed measurement module calculates the local flow velocity of each channel; a data fusion module performs weighted fusion to obtain the average flow velocity; a dynamic parameter compensation module calculates the correction coefficient based on pressure and temperature to compensate for the flow velocity; a flow calculation module obtains the standard flow; a human-computer interaction module realizes display and parameter configuration; a communication module uploads data and receives instructions; and a storage module stores historical data and parameters.

[0026] It should be noted that this multi-channel gas ultrasonic flowmeter has achieved significant technical advantages through the collaborative design of the hardware and software layers: in terms of hardware, the flange 1, sealing groove 2 and sealing ring strengthen the sealing of the pipeline 4, the uniform length of the installation 5 ensures the path consistency of the ultrasonic transducer 12, and the redundant layout of the multi-channel array and pressure sensor 8 and temperature sensor 11 lays the foundation for accurate measurement; in terms of software, wavelet noise reduction and sliding average preprocessing filter out noise, the weighted fusion algorithm combined with dynamic weight adjustment accurately fits complex flow states, dynamic compensation of pressure and temperature corrects the impact of operating condition fluctuations, and exponential smoothing and abnormal reset mechanisms ensure stable flow output. This overall solves the problems of poor flow field adaptability and insufficient accuracy in variable operating conditions of traditional flowmeters. At the same time, the hardware redundancy and software verification mechanism improve the long-term operational reliability of the system, providing a high-precision and high-stability solution for gas metering.

[0027] In this application, the ultrasonic transducer 12 time signal, pressure and temperature data are collected and packaged for transmission: Receive the downstream / reverse flow propagation time signals of N groups of ultrasonic transducers 12 through the drive interface connected to the terminal box 9, with a sampling frequency of ≥1kHz, and record the channel number; where N ≥2; Collect real-time pressure data from the pressure sensor 8 and real-time temperature data from the temperature sensor 11, and synchronously mark the collection timestamps; The collected raw data is packaged into a frame format and transmitted to the data preprocessing module; the frame format includes the channel number, time difference, pressure value, temperature value, and timestamp.

[0028] It should be noted that the sampling frequency ≥ 1kHz ensures the time resolution of flow velocity measurement, multi-channel synchronous acquisition captures the flow velocity characteristics of different areas of the pipeline cross-section, and the timestamp synchronization mechanism ensures the temporal and spatial matching of pressure and temperature parameters with ultrasonic data. The standardized frame format provides standardized input for noise reduction, verification and collaboration of various modules in data preprocessing, which improves the quality of raw data of flow measurement from the source and lays a reliable data foundation for subsequent high-precision flow velocity calculation and dynamic compensation.

[0029] In this application, the data preprocessing module performs noise reduction and verification on the data and then transmits it in batches: The ultrasonic time difference signal is subjected to a wavelet threshold noise reduction algorithm (specifically, the db4 wavelet basis is selected and the number of decomposition layers is 3) to filter out the high-frequency noise introduced by electromagnetic interference and pipeline 4 vibration; Sliding average filtering (window size 5 sampling points) is used for pressure and temperature data to eliminate instantaneous fluctuation noise; Invalid data are eliminated through validity verification rules (ultrasonic time difference must be within the preset threshold range [50ns, 500ns], pressure value ≤ rated pressure of pipeline 4, temperature value within the range of -40℃~120℃), and invalid data are supplemented by the weighted average of the previous three valid data; The preprocessed data is transmitted to the multi-channel speed measurement module and the dynamic parameter compensation module.

[0030] It should be noted that the data preprocessing mechanism adopts differentiated processing strategies for different types of data characteristics, which significantly improves the data quality: the ultrasonic time difference signal is decomposed into 3 layers of db4 wavelet basis by wavelet threshold denoising, accurately filtering out electromagnetic interference and high-frequency noise of pipeline 4 vibration, ensuring the purity of the core data of flow velocity calculation; the pressure and temperature data are subjected to sliding average filtering with a 5-sampling point window, effectively smoothing instantaneous fluctuations and enhancing parameter stability; abnormal data is eliminated by validating the threshold range, and gaps are filled with the weighted average of the previous 3 valid data to avoid invalid data interfering with subsequent calculations, reducing noise interference and correcting data anomalies at the source of the data, providing high-quality input for the accuracy of multi-channel velocity measurement and the reliability of dynamic parameter compensation, reducing the impact of original data errors on the final flow measurement results, and further consolidating the foundation for high-precision measurement of the system.

[0031] In this application, the channel velocity measurement module calculates the local flow velocity of each channel as follows: Obtain the pre-processed ultrasonic data, identify the ultrasonic propagation path length of any channel and record it as L, identify the time difference between the downstream and upstream propagation time signals of the channel and record it as , and the downstream propagation time is recorded as , the countercurrent propagation time is recorded as ; According to the preset formula Calculate the local flow velocity of each channel, where represents the local flow velocity of vocal tract i; The local flow velocity of each channel is traversed, the channel number is marked and transmitted to the data fusion module.

[0032] It should be noted that the standardized parameter extraction and formula calculation of the channel velocity measurement module ensures the accuracy of the single-channel flow velocity measurement, provides a reliable local flow velocity basis for subsequent multi-channel data fusion, avoids the influence of the overall flow field fitting accuracy due to the amplification of the single-channel calculation error, and is a key link in achieving multi-channel collaborative high-precision measurement.

[0033] In this application, the data fusion module performs weighted fusion to obtain the average flow rate, specifically: The position weight of each channel on the pipe section 4 is obtained as , i=1,2,...,N, N is the total number of channels; the weighted average algorithm is used to calculate the average flow rate, the formula is ; The consistency check is performed on the local flow velocity and the average flow velocity of each channel: if the deviation between the local flow velocity and the average flow velocity is greater than the deviation threshold, a position weight adjustment instruction for the channel is generated; the position weight adjustment instruction is used to adjust the position weight; after the position weight is adjusted, the weighted average algorithm is used again for calculation; the average flow velocity is transmitted to the flow calculation module.

[0034] It should be noted that the data fusion module has significantly improved the accuracy and reliability of the average flow velocity calculation through a scientific weighted fusion mechanism and dynamic adjustment strategy: weighted averaging is performed based on the position weights of each channel on the 4 sections of the pipe, fully considering the non-uniformity of the flow velocity distribution in the pipe section, which is more in line with the actual flow field characteristics than the traditional simple average; the deviation between the local flow velocity and the average flow velocity is compared through consistency verification, and weight adjustment instructions are generated and recalculated for abnormal channels that exceed the threshold, effectively reducing the interference of individual channel data anomalies on the overall result, and realizing dynamic adaptation to complex flow states. Through differentiated allocation and real-time correction of weights, multi-channel information is accurately integrated, avoiding the flow field fitting deviation caused by single or averaging processing, providing a basis for average flow velocity that is closer to the actual value for subsequent flow calculations, and further improving the system's adaptability to complex working conditions.

[0035] In this application, the position weight of each channel on the cross section of the pipe 4 is The acquisition logic is: The numerical law velocity distribution model based on the 4-section pipeline: ,in is the flow velocity at a distance r from the center of the pipe 4, is the maximum flow velocity at the center of pipe 4, R is the radius of pipe 4, is the equivalent radius of the ultrasonic transducer 12 installation position, and the cross section of the pipe 4 is divided into N flow velocity characteristic areas corresponding to the sound channels one by one; Calculate the theoretical flow rate integral ratio of each area as the initial position weight ,satisfy ; When the flowmeter is installed and debugged, a calibration gas with a uniform flow rate is introduced to collect the actual local flow rate measured in each channel; Calculate the variance of the actual flow velocity distribution ,in, represents the local flow velocity measured in the calibration phase for the i-th channel, To calibrate the average flow velocity, the formula is: ; Set the allowed velocity distribution variance threshold ,like , for the initial position weight Correction is made, and the correction formula is , where k is the correction coefficient, used to ensure the corrected weight , and finally get the initial position of each channel ; The position weight adjustment instruction is used to adjust the position weight. The specific process is as follows: The position weight adjustment instruction corresponding to the position weight of channel j is recorded as , identify the local flow velocity of vocal tract j , the local flow velocity through acoustic channel j With average flow rate Calculate the deviation , adjust the amplitude according to the degree of deviation: like , then reduce ; like , then reduce ; like , then reduce ; After adjusting the weight of a single channel, rebalance the weights of the remaining channels. Let the sum of the weights before adjustment be , the weight of channel j after adjustment becomes , the weight reduction is ; The weights of the remaining N-1 channels are distributed according to the original weight ratio , the correction formula is: , make sure that after correction , complete the dynamic adjustment of position weight.

[0036] It should be noted that the position weight acquisition and dynamic adjustment mechanism uses a three-layer logic of theoretical modeling, actual calibration, and dynamic correction to make the multi-channel fusion results more in line with the actual flow state, significantly improving the measurement robustness of the flow meter in complex flow fields and temporary sensor anomaly scenarios.

[0037] In this application, the dynamic parameter compensation module calculates the correction coefficient to compensate the flow rate based on the pressure and temperature, specifically: Receive pre-processed pressure data P and temperature data T and convert them into absolute pressure , absolute temperature ; The sound velocity correction coefficient k is derived based on the ideal gas state equation, and the formula is: ,in is the standard pressure, is the standard state temperature; The correction coefficient is used to dynamically compensate the average flow rate. The compensation formula is: , the compensated flow rate Transmitted to the flow calculation module.

[0038] It should be noted that the dynamic parameter compensation module effectively eliminates the impact of operating condition fluctuations on flow rate measurement through real-time monitoring and scientific correction of pressure and temperature, breaking through the limitation of traditional flow meters that ignore changes in operating parameters. It corrects the sound velocity deviation caused by pressure fluctuations and temperature drift in real time, ensuring the stability and accuracy of flow rate measurement under variable operating conditions, providing a reliable compensated data basis for subsequent standard flow calculations, and significantly improving the adaptability of the flow meter to complex industrial environments.

[0039] In this application, the flow calculation module obtains the standard flow, specifically: Calculate the gas flow rate under standard conditions based on the compensated flow rate, identify the cross-sectional area S of the pipe 4, and calculate the volume flow rate , the formula is , where 3600 is the hour conversion factor, and the cross-sectional area S of pipe 4 is calculated based on the inner diameter D of pipe 4: ; The flow data is smoothed in real time to output a stable flow value. The exponential smoothing method is used. The specific process is as follows: After the flow meter is started for the first time or after calibration, Original flow data, calculate the initial smoothing value As a benchmark, the formula is , the initial smoothing value is used as the starting input for subsequent exponential smoothing iterations; When the flow meter is operating normally, the current raw flow data is collected in real time , iteratively calculate the smoothed flow value based on the exponential smoothing formula , the formula is ,in It is a preset smoothing coefficient used to balance the responsiveness of current traffic data and the stability of historical smoothing values. is the smoothed flow value at the previous moment, and at the initial iteration , The stable flow value output at the current moment is used for subsequent display, storage or uploading; If the current raw traffic data If the data exceeds the preset range, it will be directly judged as abnormal data, and the exponential smoothing calculation will be skipped, and the smoothing value of the previous moment will be maintained. As output; If abnormal traffic data is collected for h consecutive times (h is specifically between 3 and 5), a traffic abnormality alarm is triggered, and the human-computer interaction module prompts, and the smooth iteration is automatically reset and the initial Valid historical data calculation , resume the normal iteration process.

[0040] It should be noted that the flow calculation module significantly improves the accuracy and stability of standard flow measurement through precise flow conversion and intelligent smoothing processing mechanism, realizes the precise conversion from compensated flow rate to standard flow, improves data stability through smoothing processing, and enhances system robustness through abnormal fault tolerance mechanism, providing a complete solution for flow measurement with accuracy, stability and fault tolerance.

[0041] In this application, the human-computer interaction module implements display and parameter configuration, specifically: Receive the results of the flow calculation module and display the current flow, flow rate of each channel, pressure, temperature and compensation coefficient in real time on the LCD screen; Respond to key input commands, support parameter configuration, and store the configuration parameters in the storage module; When the data exceeds the limit, an alarm will be triggered on the display screen.

[0042] It should be noted that the human-computer interaction module realizes efficient interaction between the flow meter and the user through diversified information display and flexible parameter configuration functions, significantly improving the usability and operability of the system.

[0043] In this application, the communication module uploads data and receives instructions, specifically: Through the communication interface of the terminal box 9, which supports RS485 / Modbus protocol, real-time flow, pressure, temperature, channel status and other data are uploaded to the external control system in a preset format (32 bytes per frame, including check bits); Receive control instructions from external devices, parse them, transmit them to the corresponding module for execution, and return the execution results.

[0044] It should be noted that the communication module realizes efficient data interaction between the flow meter and the external system through standardized interface and protocol design, significantly improving the system's integration and remote controllability.

[0045] In this application, the storage module stores historical data and parameters, as follows: Store historical flow data, pressure / temperature data and abnormal event logs by timestamp; Save system configuration parameters (such as channel weight, standard status parameters, communication protocol parameters, etc.), and support parameter loss after power failure; the system configuration parameters include channel weight, standard status parameters, communication protocol parameters, etc. Provides a data query interface that supports querying historical data for a specified time period through the human-computer interaction module or communication module.

[0046] It should be noted that the storage module provides solid support for the flow meter's operation traceability, parameter reuse and problem troubleshooting through comprehensive data storage and reliable parameter retention mechanism.

[0047] The formulas for velocity calculation, weight adjustment, and compensation coefficients involved in this solution are derived from extensive measured data through software simulation and optimization, accurately fitting actual flow field characteristics. Dimensionlessness is employed in the calculations, which can be achieved through conventional methods such as standardization and normalization, which are not detailed here. Preset parameters in the formulas (such as smoothing coefficients and deviation thresholds) are flexibly set by those skilled in the art based on actual operating conditions, such as pipeline specifications and media types.

[0048] The above embodiments can be implemented via software, hardware, firmware, or any combination thereof. When implemented via software, they can be embodied as a computer program product containing computer instructions or programs that, when loaded and executed, implement the core processes of this solution, such as flow calculation and parameter compensation. The computer instructions can be stored on a computer-readable storage medium such as a USB flash drive, hard drive, ROM, RAM, magnetic disk, or optical disk, or transmitted between devices via wired or wireless means.

[0049] It should be noted that the program numbers for each flow do not represent the order of execution; the order is determined by functional logic. The division of units is merely a logical distinction, and actual implementation can be achieved through integration or separation. Each functional unit can be implemented through electronic hardware or a combination of hardware and software, depending on the design constraints of the application scenario, but all implementations are within the scope of this solution.

[0050] Other embodiments of the present invention will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

[0051] It should be understood that the present invention is not limited to the exact construction described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A multi-channel gas ultrasonic flowmeter, characterized in that: It includes hardware layer and software layer, which work together to realize multi-channel speed measurement and dynamic parameter compensation functions; The hardware layer includes a pipe (4), and connecting mechanisms are fixedly connected at both ends of the pipe (4). The connecting mechanisms include flanges (1) at both ends of the pipe (4), and connecting holes (3) are equidistantly provided on the flanges (1). A sealing groove (2) is provided inside the connecting hole (3), and a sealing ring can be installed in the sealing groove (2); a detection mechanism is relatively installed on both sides of the pipe (4), and the detection mechanism includes a mounting tube (5) fixedly connected to both sides of the pipe (4), and the mounting tube (5) has the same length in the same vertical direction, and is threadedly connected to an anti-drop cap (6) at one end away from the pipe (4), and an ultrasonic transducer is installed at the end located inside the pipe (4). The ultrasonic transducer (12) is connected to the terminal box (9) through the guide tube (7); an auxiliary detection mechanism is installed on the upper end of the pipeline (4), including a pressure sensor (8) and a temperature sensor (11) in the detection holes at both ends above the pipeline (4); a terminal box (9) with a terminal and a sealing structure is fixed on the pipeline (4), and the terminal box (9) is connected to the pressure sensor (8) and the temperature sensor (11) through a wire. The upper end of the terminal box is fixed to a control mechanism, which includes a fixed tube and a control box (10) at the other end. The control box (10) is equipped with an LCD display and buttons. The software layer runs on the control mechanism, including a data acquisition module, which collects the time signal, pressure and temperature data of the ultrasonic transducer (12) and packages and transmits them; a data preprocessing module performs noise reduction and verification on the data and then transmits them separately; a multi-channel velocity measurement module calculates the local flow velocity of each channel; and a data fusion module performs weighted fusion to obtain an average flow velocity, specifically: The position weight of each channel on the cross section of the pipe (4) is obtained as , i=1,2,...,N, N is the total number of channels; the weighted average algorithm is used to calculate the average flow rate, the formula is ; Perform consistency check on the local flow velocity and average flow velocity of each channel: if the deviation between the local flow velocity and the average flow velocity is greater than the deviation threshold, generate a position weight adjustment instruction for the channel; the position weight adjustment instruction is used to adjust the position weight, and the specific process is as follows: The position weight adjustment instruction corresponding to the position weight of channel j is recorded as , identify the local flow velocity of vocal tract j , the local flow velocity through acoustic channel j With average flow rate Calculate the deviation , adjust the amplitude according to the degree of deviation; After adjusting the weight of a single channel, rebalance the weights of the remaining channels. Let the sum of the weights before adjustment be , the weight of channel j after adjustment becomes , the weight reduction is ; The weights of the remaining N-1 channels are distributed according to the original weight ratio , the correction formula is: , make sure that after correction , complete the dynamic adjustment of the position weight; after adjusting the position weight, re-calculate using the weighted average algorithm; The average flow rate is transmitted to the flow calculation module; the dynamic parameter compensation module calculates the correction coefficient based on the pressure and temperature to compensate for the flow rate; the flow calculation module obtains the standard flow rate; the human-computer interaction module realizes the display and parameter configuration; The communication module uploads data and receives instructions; the storage module stores historical data and parameters.

2. A multi-channel gas ultrasonic flowmeter according to claim 1, characterized in that: Collect the ultrasonic transducer (12) time signal, pressure and temperature data and package and transmit them: Receive the downstream / reverse flow propagation time signals of N groups of ultrasonic transducers (12) through a drive interface connected to the terminal box (9), wherein the sampling frequency is ≥1kHz, and record the channel number; Collecting real-time pressure data from the pressure sensor (8) and real-time temperature data from the temperature sensor (11), and synchronously marking the collection timestamps; Pack the collected raw data into frame format and transmit it to the data preprocessing module; The frame format includes channel number, time difference, pressure value, temperature value, and timestamp.

3. The multi-channel gas ultrasonic flowmeter according to claim 1, characterized in that: The data preprocessing module performs noise reduction and verification on the data before transmitting it in batches: The wavelet threshold noise reduction algorithm is used for the ultrasonic time difference signal to filter out the high-frequency noise introduced by electromagnetic interference and pipeline (4) vibration; Use sliding average filtering on pressure and temperature data to eliminate instantaneous fluctuation noise; Invalid data is eliminated through validity check rules, and invalid data is supplemented by the weighted average of the valid data of the previous set number of times; The preprocessed data is transmitted to the multi-channel speed measurement module and the dynamic parameter compensation module.

4. The multi-channel gas ultrasonic flowmeter according to claim 1, characterized in that: The channel velocity measurement module calculates the local flow velocity of each channel as follows: Obtain the pre-processed ultrasonic data, identify the ultrasonic propagation path length of any channel and record it as L, identify the time difference between the downstream and upstream propagation time signals of the channel and record it as , and the downstream propagation time is recorded as , the countercurrent propagation time is recorded as ; According to the preset formula Calculate the local flow velocity of each channel, where represents the local flow velocity of vocal tract i; The local flow velocity of each channel is traversed, the channel number is marked and transmitted to the data fusion module.

5. The multi-channel gas ultrasonic flowmeter according to claim 1, characterized in that: The position weight of each channel on the cross section of the pipe (4) The acquisition logic is: The numerical law velocity distribution model based on the pipe (4) section: ,in is the flow velocity at a distance r from the center of the pipe (4), is the maximum flow velocity at the center of pipe (4), R is the radius of pipe (4), The equivalent radius of the ultrasonic transducer (12) installation position is used to divide the cross section of the pipe (4) into N flow velocity characteristic areas corresponding to the sound channels; Calculate the theoretical flow rate integral ratio of each area as the initial position weight ,satisfy ; When the flowmeter is installed and debugged, a calibration gas with a uniform flow rate is introduced to collect the actual local flow rate measured in each channel; Calculate the variance of the actual flow velocity distribution ,in, represents the local flow velocity measured in the calibration phase for the i-th channel, To calibrate the average flow velocity, the formula is: ; Set the allowed velocity distribution variance threshold ,like , for the initial position weight Correction is made, and the correction formula is , where k is the correction coefficient, used to ensure the corrected weight , and finally get the initial position of each channel .

6. The multi-channel gas ultrasonic flowmeter according to claim 1, characterized in that: The dynamic parameter compensation module calculates the correction coefficient to compensate the flow rate based on pressure and temperature, specifically: Receive pre-processed pressure data P and temperature data T and convert them into absolute pressure , absolute temperature ; The sound velocity correction coefficient k is derived based on the ideal gas state equation, and the formula is: ,in is the standard pressure, is the standard state temperature; The correction coefficient is used to dynamically compensate the average flow rate. The compensation formula is: , the compensated flow rate Transmitted to the flow calculation module.

7. The multi-channel gas ultrasonic flowmeter according to claim 1, characterized in that: The flow calculation module obtains the standard flow, specifically: Calculate the gas flow rate under standard conditions based on the compensated flow rate, identify the cross-sectional area S of the pipe (4), and calculate the volume flow rate , the formula is , where 3600 is the hour conversion factor, and the cross-sectional area S of the pipe (4) is calculated based on the inner diameter D of the pipe (4): ; The flow data is smoothed in real time to output a stable flow value. The exponential smoothing method is used. The specific process is as follows: After the flow meter is started for the first time or after calibration, Original flow data, calculate the initial smoothing value As a benchmark, the formula is , the initial smoothing value is used as the starting input for subsequent exponential smoothing iterations; When the flow meter is operating normally, the current raw flow data is collected in real time , iteratively calculate the smoothed flow value based on the exponential smoothing formula , the formula is ,in is the preset smoothing coefficient, is the smoothed flow value at the previous moment, and at the initial iteration , The stable flow value output at the current moment; If the current raw traffic data If the data exceeds the preset range, it will be directly judged as abnormal data, and the exponential smoothing calculation will be skipped, and the smoothing value of the previous moment will be maintained. As output; If abnormal flow data is collected for h consecutive times, the abnormal flow alarm is triggered, the human-computer interaction module prompts, and the smooth iteration is automatically reset and the initial Valid historical data calculation , resume the normal iteration process.

8. The multi-channel gas ultrasonic flowmeter according to claim 1, characterized in that: The human-computer interaction module realizes display and parameter configuration, specifically: Receive the results of the flow calculation module and display the current flow, flow rate of each channel, pressure, temperature and compensation coefficient in real time on the LCD screen; Respond to key input commands, support parameter configuration, and store the configuration parameters in the storage module; When the data exceeds the limit, an alarm will be triggered on the display screen.

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