Ultrasonic gas meter range expansion system

Abstract

The invention discloses an ultrasonic gas meter range expansion system, and belongs to the technical field of ultrasonic gas meters. The system comprises a signal acquisition module, the signal acquisition module is used for acquiring pulse signals on a gas meter, processing the pulse signals at sampling frequency and improving the measurement sensitivity of the pulse signals, and the signal acquisition module sends the acquired pulse signals to a signal processing end; the signal processing end is used for upgrading the pulse signal to obtain a high-precision pulse signal, so that the time difference measurement precision is improved; according to the ultrasonic gas meter, the pulse signal is processed, so that the flow measurement precision in a high-flow-rate mode and a low-flow-rate mode is improved, the measurement range of the ultrasonic gas meter is widened, and the measurement precision in the range from the low flow rate to the high flow rate is guaranteed; and through real-time temperature and pressure compensation, the gas meter can stably work under different environmental conditions, and the measuring range of the ultrasonic gas meter is further widened.

Description

Technical Field

[0001] The invention relates to the technical field of ultrasonic gas meters, and more specifically to a range extension system for ultrasonic gas meters. Background Art

[0002] Ultrasonic gas meters use the time difference method to measure the gas flow rate. There is usually a pair of ultrasonic transducers inside the gas meter, which are installed on both sides of the fluid pipeline. The pair of transducers can transmit and receive ultrasonic pulse signals to each other. When the ultrasonic wave is transmitted from one transducer to another, the flow rate of the fluid will cause the difference in the ultrasonic wave propagation time. By accurately measuring the difference in ultrasonic wave propagation time in the downstream and upstream, the meter can calculate the gas flow rate.

[0003] The error caused by the change of sound velocity with fluid temperature in the time difference method is small and the accuracy is high. However, ultrasonic gas meters are medium and low pressure gas measuring instruments. Such instruments have a small measurement range and a small range ratio. Moreover, such measuring instruments are easily affected by the flow field and cannot adjust the range according to needs, which limits their scope of use. Summary of the invention

[0004] In view of the deficiencies in the prior art, an object of the present invention is to provide a range extension system for an ultrasonic gas meter.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] Ultrasonic gas meter range extension system, including:

[0007] The signal acquisition module is used to collect the pulse signal on the gas meter and process the pulse signal at the sampling frequency to improve the measurement sensitivity of the pulse signal. At the same time, the signal acquisition module sends the collected pulse signal to the signal processing end;

[0008] The signal processing end performs quality improvement processing on the pulse signal to obtain a high-precision pulse signal and improve the time difference measurement accuracy;

[0009] Compensation module: The compensation module tracks the data that affects the measurement accuracy and dynamically adjusts the flow output according to the data to ensure stable and high-precision flow measurement under different working conditions;

[0010] The early warning module monitors the data during the operation of the ultrasonic gas meter, generates an abnormal index by processing the data, and issues an alarm based on the abnormal index.

[0011] As a further solution of the present invention, the specific steps of the signal acquisition module performing sampling frequency processing include:

[0012] On the basis of conventional ultrasonic pulse signal sampling, two sampling modes are set, and the sampling modes are divided into low flow rate mode and high flow rate mode;

[0013] When the gas flow rate is in low flow rate mode, a low ultrasonic frequency is used to increase the resolution of the time difference and improve the low-speed measurement sensitivity;

[0014] When the gas flow rate is in high flow rate mode, switch to high frequency sampling to avoid measurement errors caused by high-speed flow.

[0015] As a further solution of the present invention, the steps of improving the quality of the pulse signal at the signal processing end include: using high-frequency sampling technology to improve the resolution of the ultrasonic pulse signal, and using a high-performance digital signal processor to process the signal in real time; eliminating environmental interference and signal fluctuations through filtering and noise reduction algorithms.

[0016] As a further solution of the present invention, the compensation module includes a measuring unit and a flow compensation unit; the measuring unit is used to collect temperature data and pressure data of the ultrasonic gas meter through a temperature sensor and a pressure sensor, and send the temperature data and pressure data to the flow compensation unit; the flow compensation unit processes the temperature data and pressure data to obtain a compensated flow value.

[0017] As a further solution of the present invention, the measuring unit obtains temperature data from temperature sensors at multiple locations on the gas meter, and the temperature sensors at multiple locations on the gas meter are used to monitor the temperature inside and outside the gas meter in real time; obtains pressure data from pressure sensors at multiple locations in the gas meter, obtains the pressure field distribution inside the gas meter, and the pressure sensors at multiple locations in the gas meter monitor changes in gas density.

[0018] As a further solution of the present invention, the specific steps of the flow compensation unit for processing include:

[0019] Step 1: Perform weighted average of multiple temperature values ​​in the temperature data to obtain the weighted average temperature; the weighted average temperature calculation formula is: Where T avg is the weighted average temperature, w i is the weight factor, the value is 0.453, T i is the temperature value of each temperature sensor;

[0020] According to the weighted average temperature, the piecewise linear compensation formula is set to perform temperature compensation on the measurement results to obtain the corrected sound velocity CT to ensure that the measurement accuracy is consistent under high and low temperature conditions; the compensation formula is: Where CT is the ultrasonic velocity after temperature compensation, C re is the speed of sound under standard conditions, T re is the temperature under standard conditions;

[0021] The compensated sound velocity CT directly affects the flow velocity calculation, minimizing the impact of temperature changes on signal processing;

[0022] Step 2: Using the pressure compensation algorithm formula according to the weighted average temperature and the pressure values ​​of multiple pressure sensors, the compensated flow QC after pressure compensation is obtained to reduce the flow deviation under high pressure and low pressure conditions;

[0023] Pressure compensation formula Among them, α is the nonlinear compensation coefficient, which is usually taken as 0.8964; P avg is the average value of multiple actual pressure values; P re is the pressure under standard conditions; Q is the measured flow rate, and the measurement formula is Q = A × v × (1-ε), A is the pipe cross-sectional area, v is the gas flow rate, and ε is the signal processing error value, which is a fixed value; T re is the temperature under standard conditions.

[0024] As a further solution of the present invention, the specific processing steps of the early warning module include:

[0025] The early warning module extracts the temperature value, pressure value and flow value measured in the compensation module, and calculates the abnormal index through the abnormal formula;

[0026] The abnormal formula is Among them, a1, a2 and a3 are the weight coefficients of each parameter; T th , P th and Q th They are the alarm thresholds for temperature, pressure and flow values ​​respectively;

[0027] Generate an alarm level by comparing the abnormal index with the preset abnormal range value;

[0028] When the abnormality index is less than or equal to the minimum value of the abnormal range, the parameter is judged to have a small deviation from the range and a normal operation signal is generated; when the abnormality index is within the abnormal range, the parameter is judged to have a significant deviation and a mild alarm is generated, and the user is advised to check; when the abnormality index is greater than or equal to the maximum value of the abnormal range, the parameter is judged to have a serious deviation and a severe alarm is generated, and the machine is immediately shut down for maintenance.

[0029] The maintenance terminal displays the alarm level generated by the early warning module and arranges personnel for maintenance according to the alarm level;

[0030] The operation steps of the maintenance terminal include:

[0031] The maintenance terminal displays the alarm level generated by the early warning module, generates different levels of alarm sounds according to different alarm levels, and displays temperature, pressure and flow rate data at the same time;

[0032] The maintenance terminal arranges personnel to perform maintenance according to the alarm level. The specific steps include:

[0033] Get the minor alarms in the alarm level and arrange for the on-duty personnel to check;

[0034] Get the severe alarm in the alarm level, get the work information of the personnel, which includes the work type, working hours, maintenance times and professional title level of the personnel, set different work types to correspond to a different work association value, match the work type in the work information with all the work types in the database to obtain the corresponding work association value and mark it as AG; take the value of the working hours and mark it as AS; take the value of the maintenance times and mark it as AC; mark the professional title as AD; match the professional title with the professional title table preset in the database to obtain the corresponding professional title association value and mark it as GLZ; normalize the marked data and take the value, use the formula

[0035] SR down =AG×GLZ×(c1×AS+c2×AC) to calculate the shift value of the personnel; where c1 and c2 represent different proportional coefficients; several shift values ​​are arranged in descending order to obtain a shift sorting set, and the idle personnel in the shift sorting set are arranged for maintenance from the front to the back, and the severe alarms in the alarm level are repaired and maintained;

[0036] Through this setting, experienced personnel are arranged to deal with problems in severe alarms first, and abnormalities in minor alarms are checked by on-duty personnel to avoid the situation where there are many abnormalities and personnel cannot be arranged to check and repair them in time. At the same time, abnormalities in severe alarms are handled more promptly and properly.

[0037] Compared with the existing solutions, the present invention has the following beneficial effects:

[0038] The present invention improves the flow measurement accuracy in high flow rate mode and low flow rate mode by processing the pulse signal, widens the measurement range of the ultrasonic gas meter, and ensures the measurement accuracy from low flow rate to high flow rate; through real-time temperature and pressure compensation, the gas meter can work stably under different environmental conditions, further widening the measurement range of the ultrasonic gas meter. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The present invention is a system diagram of an ultrasonic gas meter range extension system.

[0040] Figure 2 This is a system diagram of the ultrasonic gas meter range extension system in Example 2. DETAILED DESCRIPTION

[0041] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

[0042] Example 1

[0043] Reference Figure 1 The present invention is an ultrasonic gas meter range extension system, including a signal acquisition module, a signal processing terminal and a compensation module.

[0044] It is important to understand that the core of the ultrasonic gas meter is to calculate the gas flow rate by the change in the propagation speed of the ultrasonic pulse signal in the gas medium;

[0045] The signal acquisition module is used to collect the pulse signal on the gas meter and process the pulse signal at the sampling frequency to improve the measurement sensitivity of the pulse signal; at the same time, the signal acquisition module sends the collected pulse signal to the signal processing end;

[0046] The specific steps of the signal acquisition module for sampling frequency processing include:

[0047] On the basis of conventional ultrasonic pulse signal sampling, two sampling modes are set, and different sampling frequencies are set for different flow velocity ranges, so as to improve the measurement sensitivity of each velocity segment; the sampling mode is divided into low flow velocity mode and high flow velocity mode;

[0048] When the gas flow rate is in low flow rate mode, a low ultrasonic frequency is used to increase the resolution of the time difference and improve the low-speed measurement sensitivity;

[0049] When the gas flow rate is in high flow rate mode, switch to high frequency sampling to avoid measurement errors caused by high-speed flow;

[0050] The signal acquisition module presets the range of flow rate values ​​in the low flow rate mode and the range of flow rate values ​​in the high flow rate mode. When the gas flow rate is in one of the modes, the system detects the flow rate in real time and automatically switches the sampling mode.

[0051] The signal processing end improves the quality of the pulse signal to obtain a high-precision pulse signal, thereby improving the time difference measurement accuracy;

[0052] The steps of improving the quality of the pulse signal at the signal processing end include:

[0053] High-frequency sampling technology is used to improve the resolution of ultrasonic pulse signals, and high-performance digital signal processors are used to process signals in real time, thereby improving the accuracy of time difference measurement and reducing errors introduced by noise.

[0054] Environmental interference and signal fluctuations are eliminated through filtering and noise reduction algorithms.

[0055] By processing the pulse signal, the flow measurement accuracy in high flow rate mode and low flow rate mode is improved, and the measurement range of the ultrasonic gas meter is widened.

[0056] Since changes in temperature and pressure will affect the density and sound velocity of the gas, and thus affect the measurement accuracy, these parameters need to be dynamically compensated to maintain the accuracy of flow measurement;

[0057] Compensation module: The compensation module tracks the data that affects the measurement accuracy and dynamically adjusts the flow output according to the data to ensure stable and high-precision flow measurement under different working conditions. The compensation module includes a measurement unit and a flow compensation unit;

[0058] The measuring unit is used to collect temperature data and pressure data of the ultrasonic gas meter through a temperature sensor and a pressure sensor, and send the temperature data and pressure data to the flow compensation unit;

[0059] Acquire temperature data of temperature sensors at multiple locations of the gas meter. The temperature sensors at multiple locations of the gas meter are used to monitor the temperature inside and outside the gas meter in real time.

[0060] Obtain pressure data from pressure sensors at multiple locations in the gas meter, obtain the pressure field distribution inside the gas meter, and monitor changes in gas density using pressure sensors at multiple locations in the gas meter;

[0061] The flow compensation unit processes the temperature data and pressure data to obtain the compensated flow value;

[0062] The specific steps of the flow compensation unit include:

[0063] Step 1: Perform weighted average of multiple temperature values ​​in the temperature data to obtain the weighted average temperature; the weighted average temperature calculation formula is: Where T avg is the weighted average temperature, w i is the weight factor, the value is 0.453, T i is the temperature value of each temperature sensor;

[0064] According to the weighted average temperature, the piecewise linear compensation formula is set to perform temperature compensation on the measurement results to obtain the corrected sound velocity CT to ensure that the measurement accuracy is consistent under high and low temperature conditions; the compensation formula is: Where CT is the ultrasonic velocity after temperature compensation, C re is the speed of sound under standard conditions, T re is the temperature under standard conditions;

[0065] The compensated sound velocity CT directly affects the flow velocity calculation, minimizing the impact of temperature changes on signal processing;

[0066] Step 2: Using the pressure compensation algorithm formula according to the weighted average temperature and the pressure values ​​of multiple pressure sensors, the compensated flow QC after pressure compensation is obtained to reduce the flow deviation under high pressure and low pressure conditions;

[0067] Pressure compensation formula Among them, α is the nonlinear compensation coefficient, which is usually taken as 0.8964; P avg is the average value of multiple actual pressure values; P re is the pressure under standard conditions; Q is the measured flow rate, and the measurement formula is Q = A × v × (1-ε), A is the pipe cross-sectional area, v is the gas flow rate, and ε is the signal processing error value, which is a fixed value; T re is the temperature under standard conditions;

[0068] The measurement of ultrasonic gas meters is affected by changes in gas temperature and pressure. By real-time monitoring of temperature and pressure values ​​and performing compensation, the accuracy of flow measurement can be maintained, the measurement range of ultrasonic gas meters can be further expanded, and higher accuracy and stability can be achieved.

[0069] Example 2

[0070] Reference Figure 2 The present invention is an ultrasonic gas meter range extension system, including a signal acquisition module, a signal processing terminal, a compensation module and an early warning module.

[0071] The signal acquisition module is used to collect the pulse signal on the gas meter and process the pulse signal at the sampling frequency to improve the measurement sensitivity of the pulse signal; at the same time, the signal acquisition module sends the collected pulse signal to the signal processing end;

[0072] The specific steps of the signal acquisition module for sampling frequency processing include:

[0073] On the basis of conventional ultrasonic pulse signal sampling, two sampling modes are set, and different sampling frequencies are set for different flow velocity ranges, so as to improve the measurement sensitivity of each velocity segment; the sampling mode is divided into low flow velocity mode and high flow velocity mode;

[0074] When the gas flow rate is in low flow rate mode, a low ultrasonic frequency is used to increase the resolution of the time difference and improve the low-speed measurement sensitivity;

[0075] When the gas flow rate is in high flow rate mode, switch to high frequency sampling to avoid measurement errors caused by high-speed flow.

[0076] The signal processing end improves the quality of the pulse signal to obtain a high-precision pulse signal, thereby improving the time difference measurement accuracy;

[0077] The steps of improving the quality of the pulse signal at the signal processing end include:

[0078] High-frequency sampling technology is used to improve the resolution of ultrasonic pulse signals, and high-performance digital signal processors are used to process signals in real time, thereby improving the accuracy of time difference measurement and reducing errors introduced by noise.

[0079] Environmental interference and signal fluctuations are eliminated through filtering and noise reduction algorithms.

[0080] Compensation module: The compensation module tracks the data that affects the measurement accuracy and dynamically adjusts the flow output according to the data to ensure stable and high-precision flow measurement under different working conditions. The compensation module includes a measurement unit and a flow compensation unit;

[0081] The measuring unit is used to collect temperature data and pressure data of the ultrasonic gas meter through a temperature sensor and a pressure sensor, and send the temperature data and pressure data to the flow compensation unit;

[0082] Acquire temperature data of temperature sensors at multiple locations of the gas meter. The temperature sensors at multiple locations of the gas meter are used to monitor the temperature inside and outside the gas meter in real time.

[0083] Obtain pressure data from pressure sensors at multiple locations in the gas meter, obtain the pressure field distribution inside the gas meter, and monitor changes in gas density using pressure sensors at multiple locations in the gas meter;

[0084] The flow compensation unit processes the temperature data and pressure data to obtain the compensated flow value;

[0085] The specific steps of the flow compensation unit include:

[0086] Step 1: Perform weighted average of multiple temperature values ​​in the temperature data to obtain the weighted average temperature; the weighted average temperature calculation formula is: Where T avg is the weighted average temperature, w i is the weight factor, the value is 0.453, T i is the temperature value of each temperature sensor;

[0087] According to the weighted average temperature, the piecewise linear compensation formula is set to perform temperature compensation on the measurement results to obtain the corrected sound velocity CT to ensure that the measurement accuracy is consistent under high and low temperature conditions; the compensation formula is: Where CT is the ultrasonic velocity after temperature compensation, C re is the speed of sound under standard conditions, T re is the temperature under standard conditions;

[0088] The compensated sound velocity CT directly affects the flow velocity calculation, minimizing the impact of temperature changes on signal processing;

[0089] Step 2: Using the pressure compensation algorithm formula according to the weighted average temperature and the pressure values ​​of multiple pressure sensors, the compensated flow QC after pressure compensation is obtained to reduce the flow deviation under high pressure and low pressure conditions;

[0090] Pressure compensation formula Among them, α is the nonlinear compensation coefficient, which is usually taken as 0.8964; P avg is the average value of multiple actual pressure values; P re is the pressure under standard conditions; Q is the measured flow rate, and the measurement formula is Q = A × v × (1-ε), A is the pipe cross-sectional area, v is the gas flow rate, and ε is the signal processing error value, which is a fixed value; T re is the temperature under standard conditions.

[0091] Since the measurement of the ultrasonic gas meter is affected by the changes in gas temperature and pressure, these parameters cannot be combined to generate an alarm for the ultrasonic gas meter. Therefore, based on Example 1, an early warning module and a maintenance terminal are set;

[0092] The early warning module monitors the data during the operation of the ultrasonic gas meter, generates an abnormal index by processing the data, and issues an alarm based on the abnormal index;

[0093] Among them, the specific processing steps of the early warning module include:

[0094] The early warning module extracts the temperature value, pressure value and flow value measured in the compensation module, and calculates the abnormal index through the abnormal formula;

[0095] The abnormal formula is Among them, a1, a2 and a3 are the weight coefficients of each parameter; T th , P th and Q th They are the alarm thresholds for temperature, pressure and flow values ​​respectively;

[0096] Generate an alarm level by comparing the abnormal index with the preset abnormal range value;

[0097] When the abnormal index is less than or equal to the minimum value of the abnormal range value, it is determined that the parameter deviation range is small and a normal operation signal is generated;

[0098] When the abnormal index is within the abnormal range, the parameter is judged to be significantly deviated, a mild alarm is generated, and the user is advised to check;

[0099] When the abnormal index is greater than or equal to the maximum value of the abnormal range value, the parameter is judged to be seriously deviated, a severe alarm is generated, and the machine is immediately shut down for maintenance;

[0100] By jointly analyzing temperature, pressure and flow fluctuations, these parameters are correlated and processed as a whole and alarms are triggered. This system improves the accuracy and reliability of alarms through multi-parameter linkage analysis.

[0101] The maintenance terminal displays the alarm level generated by the early warning module and arranges personnel for maintenance according to the alarm level;

[0102] The operation steps of the maintenance terminal include:

[0103] The maintenance terminal displays the alarm level generated by the early warning module, generates different levels of alarm sounds according to different alarm levels, and displays temperature, pressure and flow rate data at the same time;

[0104] The maintenance terminal arranges personnel to perform maintenance according to the alarm level. The specific steps include:

[0105] Get the minor alarms in the alarm level and arrange for the on-duty personnel to check;

[0106] Get the severe alarm in the alarm level, get the work information of the personnel, which includes the work type, working hours, maintenance times and professional title level of the personnel, set different work types to correspond to a different work association value, match the work type in the work information with all the work types in the database to obtain the corresponding work association value and mark it as AG; take the value of the working hours and mark it as AS; take the value of the maintenance times and mark it as AC; mark the professional title as AD; match the professional title with the professional title table preset in the database to obtain the corresponding professional title association value and mark it as GLZ; normalize the marked data and take the value, use the formula

[0107] SR down =AG×GLZ×(c1×AS+c2×AC) to calculate the shift value of the personnel; where c1 and c2 represent different proportional coefficients; several shift values ​​are arranged in descending order to obtain a shift sorting set, and the idle personnel in the shift sorting set are arranged for maintenance from the front to the back, and the severe alarms in the alarm level are repaired and maintained;

[0108] Through this setting, experienced personnel are arranged to deal with problems in severe alarms first, and abnormalities in minor alarms are checked by on-duty personnel to avoid the situation where there are many abnormalities and personnel cannot be arranged to check and repair them in time. At the same time, abnormalities in severe alarms are handled more promptly and properly.

[0109] The ultrasonic metering module with a small flow rate can be diverted by changing the flow channel to meet the metering requirements of the ultrasonic gas meter with a larger flow rate;

[0110] That is to say, part of the gas is measured by the metering module, and the other part of the gas is directly passed, and then the manufacturing is used to ensure that the diversion percentage is relatively accurate.

[0111] The metering data is amplified by software algorithms, and different proportions are used in combination with different flow rate points. The changes in proportions at different flow rate points are determined through experiments, and a complete diversion characteristic curve is formed through interpolation operations, thereby achieving accurate metering.

[0112] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0113] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. Ultrasonic gas meter range extension system, characterized in that: include: The signal acquisition module is used to collect the pulse signal on the gas meter and process the pulse signal at the sampling frequency to improve the measurement sensitivity of the pulse signal. At the same time, the signal acquisition module sends the collected pulse signal to the signal processing end; The signal processing end performs quality improvement processing on the pulse signal to obtain a high-precision pulse signal and improve the time difference measurement accuracy; Compensation module: The compensation module tracks the data that affects the measurement accuracy and dynamically adjusts the flow output according to the data to ensure stable and high-precision flow measurement under different working conditions; The early warning module monitors the data during the operation of the ultrasonic gas meter, generates an abnormal index by processing the data, and issues an alarm based on the abnormal index.

2. The ultrasonic gas meter range extension system according to claim 1, characterized in that: The specific steps of the signal acquisition module for sampling frequency processing include: On the basis of conventional ultrasonic pulse signal sampling, two sampling modes are set, and the sampling modes are divided into low flow rate mode and high flow rate mode; When the gas flow rate is in low flow rate mode, a low ultrasonic frequency is used to increase the resolution of the time difference and improve the low-speed measurement sensitivity; When the gas flow rate is in high flow rate mode, switch to high frequency sampling to avoid measurement errors caused by high-speed flow.

3. The ultrasonic gas meter range extension system according to claim 2, characterized in that: The steps for improving the quality of pulse signals at the signal processing end include: using high-frequency sampling technology to improve the resolution of ultrasonic pulse signals, and using high-performance digital signal processors to process signals in real time; and using filtering and noise reduction algorithms to eliminate environmental interference and signal fluctuations.

4. The ultrasonic gas meter range extension system according to claim 3, characterized in that: The compensation module includes a measuring unit and a flow compensation unit; the measuring unit is used to collect temperature data and pressure data of the ultrasonic gas meter through a temperature sensor and a pressure sensor, and send the temperature data and pressure data to the flow compensation unit; the flow compensation unit processes the temperature data and pressure data to obtain a compensated flow value.

5. The ultrasonic gas meter range extension system according to claim 4, characterized in that: The measuring unit obtains temperature data from temperature sensors at multiple locations in the gas meter. The temperature sensors at multiple locations in the gas meter are used to monitor the temperature inside and outside the gas meter in real time. The measuring unit obtains pressure data from pressure sensors at multiple locations in the gas meter and obtains the pressure field distribution inside the gas meter. The pressure sensors at multiple locations in the gas meter monitor changes in gas density.

6. The ultrasonic gas meter range extension system according to claim 5, characterized in that: The specific steps of the flow compensation unit include: Step 1: Perform weighted average of multiple temperature values ​​in the temperature data to obtain the weighted average temperature; the weighted average temperature calculation formula is: Where T avg is the weighted average temperature, w i is the weight factor, the value is 0.453, T i is the temperature value of each temperature sensor; According to the weighted average temperature, the piecewise linear compensation formula is set to perform temperature compensation on the measurement results to obtain the corrected sound velocity CT to ensure that the measurement accuracy is consistent under high and low temperature conditions; the compensation formula is: Where CT is the ultrasonic velocity after temperature compensation, C re is the speed of sound under standard conditions, T re is the temperature under standard conditions; The compensated sound velocity CT directly affects the flow velocity calculation, minimizing the impact of temperature changes on signal processing; Step 2: Using the pressure compensation algorithm formula according to the weighted average temperature and the pressure values ​​of multiple pressure sensors, the compensated flow QC after pressure compensation is obtained to reduce the flow deviation under high pressure and low pressure conditions; Pressure compensation formula Among them, α is the nonlinear compensation coefficient, which is usually taken as 0.8964; P avg is the average value of multiple actual pressure values; P re is the pressure under standard conditions; Q is the measured flow rate, and the measurement formula is Q = A × v × (1-ε), A is the pipe cross-sectional area, v is the gas flow rate, and ε is the signal processing error value, which is a fixed value; T re is the temperature under standard conditions.

7. The ultrasonic gas meter range extension system according to claim 6, characterized in that: The specific processing steps of the early warning module include: The early warning module extracts the temperature value, pressure value and flow value measured in the compensation module, and calculates the abnormal index through the abnormal formula; The abnormal formula is Among them, a1, a2 and a3 are the weight coefficients of each parameter; T th , P th and Q th They are the alarm thresholds for temperature, pressure and flow values ​​respectively; Generate an alarm level by comparing the abnormal index with the preset abnormal range value; When the abnormality index is less than or equal to the minimum value of the abnormal range, the parameter is judged to have a small deviation from the range and a normal operation signal is generated; when the abnormality index is within the abnormal range, the parameter is judged to have a significant deviation and a mild alarm is generated, and the user is advised to check; when the abnormality index is greater than or equal to the maximum value of the abnormal range, the parameter is judged to have a serious deviation and a severe alarm is generated, and the machine is immediately shut down for maintenance.

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