Gas micro-leakage detection method, device, equipment, medium and program product

Abstract

The application provides a gas micro-leakage detection method, device, equipment, medium and program product. The method determines sampling information of each sampling point in a plurality of sampling points of a gas meter within a preset time length, wherein the sampling information of the sampling point includes a measured pressure value of the sampling point and a predicted pressure value of the sampling point under a no-leakage working condition; according to a cavity volume of the gas meter, a micro-leakage standard deviation of the gas meter is determined from a plurality of micro-leakage standard deviations corresponding to a plurality of preset volumes, wherein the sampling information of the sampling point includes the measured pressure value of the sampling point and the predicted pressure value of the sampling point under the no-leakage working condition; for any sampling point in the plurality of sampling points, whether the sampling point meets a micro-leakage condition is judged according to the micro-leakage standard deviation of the gas meter and the sampling information of the sampling point, and if the plurality of sampling points all meet the micro-leakage condition, it is determined that the gas meter has gas micro-leakage, thereby realizing detection of gas micro-leakage and improving gas use safety.

Description

Technical Field

[0001] This application relates to the field of gas leak detection, and more particularly to a method, apparatus, equipment, medium, and program product for detecting micro-gas leaks. Background Technology

[0002] Gas leaks not only waste energy but can also cause major safety accidents such as explosions and fires. Monitoring gas leaks can help detect potential hazards in a timely manner and prevent accidents from occurring.

[0003] Existing technology detects gas leaks by monitoring changes in gas meter flow rate. Specifically, the gas meter monitors changes in gas flow rate in the pipeline in real time; these real-time changes are compared with normal flow rate changes under leak-free conditions. If a deviation exceeds a set range, a gas leak is identified.

[0004] However, if a minor gas leak occurs in the enclosed space between the gas meter's pre-valve and the gas-using device when both are closed, the gas meter will not detect the minute change in airflow, thus failing to detect the gas leak and resulting in lower gas safety. Summary of the Invention

[0005] This application provides a method, apparatus, equipment, medium, and program product for detecting micro-leaks in gas, thereby improving the safety of gas use.

[0006] Firstly, this application provides a method for detecting micro-leaks in gas, comprising:

[0007] The sampling information of each sampling point among multiple sampling points of the gas meter within a preset time period is determined, and the micro-leakage standard deviation of the gas meter is determined from the micro-leakage standard deviations corresponding to multiple preset volumes based on the cavity volume of the gas meter.

[0008] For any of the multiple sampling points, it is determined whether the sampling point meets the micro-leakage condition based on the micro-leakage standard deviation of the gas meter and the sampling information of the sampling point. If all of the multiple sampling points meet the micro-leakage condition, it is determined that there is a gas micro-leakage in the gas meter.

[0009] The cavity volume is determined based on the cavity shape, upper limit of the measurement range, and size information of the gas meter. The micro-leakage standard deviation of the gas meter is used to measure the degree of fluctuation of the residual between the predicted pressure value and the measured pressure value of the gas meter under micro-leakage conditions. The sampling information of the sampling point includes the measured pressure value of the sampling point and the predicted pressure value of the sampling point under leak-free conditions.

[0010] Secondly, this application provides a gas micro-leakage detection device, comprising:

[0011] The micro-leakage standard deviation determination module is used to determine the sampling information of each sampling point among multiple sampling points of the gas meter within a preset time period, and to determine the micro-leakage standard deviation of the gas meter from the micro-leakage standard deviations corresponding to multiple preset volumes based on the cavity volume of the gas meter.

[0012] The gas micro-leakage determination module is used to determine whether any of the multiple sampling points meets the micro-leakage condition based on the micro-leakage standard deviation and the sampling information of the sampling point. If all the multiple sampling points meet the micro-leakage condition, it is determined that there is a gas micro-leakage in the gas meter.

[0013] The cavity volume is determined based on the cavity shape, upper limit of the measurement range, and size information of the gas meter. The micro-leakage standard deviation of the gas meter is used to measure the degree of fluctuation of the residual between the predicted pressure value and the measured pressure value of the gas meter under micro-leakage conditions. The sampling information of the sampling point includes the measured pressure value of the sampling point and the predicted pressure value of the sampling point under leak-free conditions.

[0014] Thirdly, this application provides an electronic device, including: a memory and a processor;

[0015] The memory stores computer-executed instructions;

[0016] The processor executes computer execution instructions stored in the memory to implement the method as described in the first aspect.

[0017] Fourthly, this application provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the method described in the first aspect.

[0018] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the method described in the first aspect.

[0019] This application provides a method, apparatus, device, medium, and program product for detecting micro-leaks in gas. The method involves determining sampling information from multiple sampling points of a gas meter within a preset time period. The sampling information includes the measured pressure value and the predicted pressure value under leak-free conditions. Based on the gas meter's cavity volume, the method determines the micro-leak standard deviation of the gas meter from the micro-leak standard deviations corresponding to multiple preset volumes. The cavity volume is determined based on the gas meter's cavity shape, upper limit of the measurement range, and gas meter dimensions. The sampling information includes the measured pressure value and the predicted pressure value under leak-free conditions. The micro-leakage standard deviation of the gas meter is used to measure the degree of fluctuation of the residual between the predicted pressure value and the measured pressure value of the gas meter under micro-leakage conditions. For any sampling point among multiple sampling points, the micro-leakage standard deviation of the gas meter and the sampling information of the sampling point are used to determine whether the sampling point meets the micro-leakage condition. This can accurately determine whether the measured pressure value of the sampling point deviates from the allowable range of the predicted pressure value under the leak-free condition. If multiple sampling points meet the micro-leakage condition, it means that each sampling point within the preset time period deviates from the allowable range of the corresponding predicted pressure value under the leak-free condition. This confirms that there is a gas micro-leakage in the gas meter, thereby realizing the detection of gas micro-leakage and improving the safety of gas use. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0021] Figure 1 Trend graphs showing the changes in pressure and temperature within the measuring chamber over time under different conditions, provided for embodiments of this application;

[0022] Figure 2 A schematic flowchart illustrating a method for detecting minor gas leaks provided in this application embodiment;

[0023] Figure 3 This is a flowchart illustrating the process of determining the volume of a cavity according to an embodiment of this application.

[0024] Figure 4 A flowchart illustrating the construction process of a linear model corresponding to a preset shape, provided in an embodiment of this application;

[0025] Figure 5 A flowchart illustrating the process of determining the standard deviation of microleakage corresponding to a preset volume, as provided in an embodiment of this application.

[0026] Figure 6 This application provides a schematic flowchart of a method for determining whether a gas meter has a micro-leakage.

[0027] Figure 7 This is a schematic flowchart of a method for determining a preset duration provided in an embodiment of this application;

[0028] Figure 8 This is a schematic diagram of the structure of a gas micro-leakage detection device provided in an embodiment of this application;

[0029] Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0030] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0031] It should be noted that in the embodiments of this application, certain software, components, models and other existing solutions in the industry may be mentioned. These should be regarded as exemplary and are only intended to illustrate the feasibility of implementing the technical solution of this application. However, it does not mean that the applicant has used or necessarily used the solution.

[0032] First, the terms used in the embodiments of this application will be explained:

[0033] Gas meter pre-control valve: This valve, installed before the gas inlet of the gas meter, controls the flow of gas. In case of gas meter installation, replacement, or other emergencies, the pre-control valve is shut off to cut off the gas supply and ensure safety.

[0034] Diaphragm gas meters utilize the pressure difference of gas flowing within the meter body as a driving force, with the relative positions of the valve seat and valve cover controlling the gas flow distribution. The diaphragm box consists of two identical gas measuring chambers, each divided into two smaller metering chambers by a diaphragm. Gas entering the smaller metering chambers pushes the diaphragm to oscillate, driving a linkage mechanism to rotate the valve cover, controlling the sequential filling and venting of each metering chamber. Simultaneously, the linkage mechanism drives a mechanical unidirectional counter to count and display the venting volume.

[0035] Ultrasonic gas meters: These meters use the time-of-flight method to measure the difference in speed of ultrasonic signals as they propagate in the fluid with and against the current, thereby reflecting the fluid's flow rate and calculating the gas flow rate.

[0036] Micro-leaks in gas systems refer to slow and minute leaks of gas. Because the leakage flow rate and speed are small, they are usually difficult to detect with conventional flow meters or pressure sensors and do not immediately have a significant impact on the pressure or flow rate of the gas system. Although the leakage rate is slow and the leakage volume is small, if such micro-leaks persist and the gas gradually accumulates to a sufficient concentration over time, they may cause serious safety hazards such as fires or explosions.

[0037] If a minor leak occurs in the sealed space between the gas meter's pre-operated valve and the gas-using appliance when both are closed, the gas meter will not be able to detect the leak because gas meters typically rely on changes in flow rate to detect leaks. In this closed state, the gas flow is interrupted, and the gas meter cannot sense the minor leak. Therefore, the gas meter will not be able to detect the change in gas flow.

[0038] To address the aforementioned technical problems, this application proposes a method for detecting micro-leakage in gas. This method involves determining the sampling information of each sampling point among multiple sampling points of a gas meter within a preset time period. The sampling information includes the measured pressure value and the predicted pressure value under leak-free conditions. Based on the gas meter's cavity volume, the method determines the micro-leakage standard deviation of the gas meter from the micro-leakage standard deviations corresponding to multiple preset volumes. The cavity volume is determined based on the gas meter's cavity shape, upper limit of the measurement range, and the gas meter's dimensions. The sampling information includes the measured pressure value and the predicted pressure value under leak-free conditions. The micro-leakage standard deviation of the gas meter is used to measure the degree of fluctuation of the residual between the predicted pressure value and the measured pressure value of the gas meter under micro-leakage conditions. For any sampling point among multiple sampling points, the micro-leakage standard deviation of the gas meter and the sampling information of the sampling point are used to determine whether the sampling point meets the micro-leakage condition. This can accurately determine whether the measured pressure value of the sampling point deviates from the allowable range of the predicted pressure value under the leak-free condition. If multiple sampling points meet the micro-leakage condition, it means that each sampling point within the preset time period deviates from the allowable range of the corresponding predicted pressure value under the leak-free condition. This confirms that there is a gas micro-leakage in the gas meter, thereby realizing the detection of gas micro-leakage and improving the safety of gas use.

[0039] In this embodiment, the gas meter is equipped with a pressure sensor and a temperature sensor. The pressure sensor is used to measure the gas pressure inside the gas meter's cavity, and the temperature sensor is used to measure the gas temperature inside the gas meter's cavity.

[0040] In this embodiment, with the gas meter pre-valve and the gas-using equipment closed, under leak-free conditions, the combined space of the gas meter cavity, the hose from the gas meter pre-valve to the gas meter, and the hose from the gas meter to the gas-using equipment can be considered as a closed state, thus the gas meter cavity can be considered as a closed state.

[0041] The pressure of the gas inside the gas meter's cavity satisfies the ideal gas equation. The ideal gas equation is shown in formula (1) below:

[0042] (1)

[0043] Where P represents the pressure of the gas inside the cavity, V represents the volume of the cavity, n represents the amount of substance of the gas inside the cavity, R represents the gas constant, and T represents the temperature of the gas inside the cavity.

[0044] Because the gas meter's cavity is in a sealed state, the amount of gas inside the cavity is constant. When the temperature of the gas inside the cavity changes, the pressure of the gas inside the cavity will change with the temperature change.

[0045] Specifically, if the gas temperature at the beginning of a certain period is T0 and the gas pressure is P0, and the gas temperature at the end of the period is T1, then according to formula (1), the formula for calculating the gas pressure at the end of the period can be obtained as shown in formula (2):

[0046] (2)

[0047] Where P1 represents the gas pressure at the end of the time period.

[0048] Under micro-leakage conditions, gas inside the cavity leaks through the leak hole (i.e., a tiny pore, which cannot be detected by conventional flow meters or pressure sensors when the gas leaks through the leak hole). Assuming the area of ​​the leak hole is A, the leakage rate of the mass of gas inside the cavity conforms to the following formula (3):

[0049] (3)

[0050] Where m represents the mass of the gas inside the cavity, and t represents time. Represents the flow coefficient. This indicates the density of the gas inside the cavity. This represents standard atmospheric pressure. Specifically, , where M represents the molar mass of the gas inside the cavity.

[0051] Under micro-leakage conditions Therefore, based on formulas (1) and (3), the rate of change model of gas pressure inside the cavity under micro-leakage conditions can be obtained, and the rate of change model of gas pressure inside the cavity is shown in formula (4) below:

[0052] (4)

[0053] As can be seen from formula (4), under micro-leakage conditions, the relationship between the gas pressure inside the cavity and the cavity volume is inversely proportional.

[0054] In other words, under micro-leakage conditions, the larger the volume of the gas meter's cavity, the smaller the rate of change of gas pressure inside the gas meter's cavity, meaning the slower the gas leakage inside the cavity; conversely, the smaller the volume of the gas meter's cavity, the greater the rate of change of gas pressure inside the gas meter's cavity, meaning the faster the gas leakage inside the cavity.

[0055] In this embodiment, for a gas meter, the volume of the gas meter cavity is fixed. When the temperature change inside the cavity is small, the calculation result of formula (4) can be regarded as a constant. In this embodiment, the negative value of this constant is defined as the micro-leakage constant. The micro-leakage constant can be used to measure the magnitude of the micro-leakage rate. Therefore, gas meters with different cavity volumes correspond to different micro-leakage constants, and the micro-leakage constant is inversely proportional to the cavity volume.

[0056] Based on formulas (1) to (4), the pressure prediction model under leak-free conditions can be determined as follows: (5)

[0057] (5)

[0058] in, This represents the predicted pressure value at time t under leak-free operating conditions. This represents the measured pressure value at time t-1 (i.e., the actual pressure value obtained by the pressure sensor in the gas meter). This represents the measured temperature value at time t (i.e., the actual temperature value obtained by the temperature sensor in the gas meter). This represents the measured temperature value at time t-1.

[0059] The pressure prediction model under micro-leakage conditions is as follows: (6)

[0060] (6)

[0061] in, This represents the predicted pressure value at time t under micro-leakage conditions. is the micro-leakage constant.

[0062] Figure 1 This is a trend graph showing the change of pressure and temperature in the measuring chamber over time under different conditions, provided for embodiments of this application. Figure 1 In the diagram, the horizontal axis represents time (unit: minutes, abbreviated as m), and the vertical axis represents temperature or pressure. When representing pressure, the unit is Pascal; when representing temperature, the unit is degree Celsius. For example... Figure 1As shown, the curve corresponding to "Pressure (Normal)" represents the trend of pressure change in the cavity over time under leak-free conditions, the curve corresponding to "Temperature (Normal)" represents the trend of temperature change in the cavity over time under leak-free conditions, the curve corresponding to "Pressure (Slight Leakage)" represents the trend of pressure change in the cavity over time under slight leakage conditions, and the curve corresponding to "Temperature (Slight Leakage)" represents the trend of temperature change in the cavity over time under slight leakage conditions.

[0063] It should be noted that since minor gas leaks have no effect on temperature, therefore, Figure 1 In the diagram, the curve corresponding to "Temperature (Normal)" (marked in yellow) coincides with the curve corresponding to "Temperature (Minor Leakage)".

[0064] It can be seen that the temperature change trends under the no-leakage and micro-leakage conditions are consistent, while the pressure change trend under the micro-leakage condition is inconsistent with the pressure change trend under the no-leakage condition. Moreover, as time goes by and micro-leakage occurs, at the same time, the pressure under the micro-leakage condition is lower than the pressure under the no-leakage condition.

[0065] The technical solution of this application and how it solves the above-mentioned technical problems will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.

[0066] Figure 2 This is a flowchart illustrating a method for detecting micro-leaks in gas provided in this application. The executing entity of this method can be an electronic device used to implement the gas micro-leak detection method. This electronic device is implemented through software and hardware, specifically as a server deployed locally or in the cloud. The specific steps of this method are as follows:

[0067] S201. Determine the sampling information of each sampling point among multiple sampling points of the gas meter within a preset time period, and determine the micro-leakage standard deviation of the gas meter from the micro-leakage standard deviations corresponding to multiple preset volumes based on the gas meter's cavity volume; wherein, the cavity volume is determined based on the gas meter's cavity shape, upper limit of measurement range, and gas meter size information, and the sampling information of the sampling points includes the measured pressure value of the sampling point and the predicted pressure value of the sampling point under leak-free conditions, and the micro-leakage standard deviation of the gas meter is used to measure the degree of fluctuation of the residual between the predicted pressure value and the measured pressure value of the gas meter under micro-leakage conditions.

[0068] The preset duration can be set according to the needs of actual application, and this embodiment does not limit it. For example, the preset duration can be set according to the micro-leakage constant corresponding to the cavity volume of the gas meter. The smaller the micro-leakage constant, the larger the preset duration should be.

[0069] In this step, the pressure and temperature values ​​of each sampling point in multiple sampling points within a preset time period are obtained through the pressure and temperature sensors in the gas meter; for any sampling point among the multiple sampling points, the predicted pressure value of the sampling point under leak-free conditions is calculated according to the aforementioned formula (5).

[0070] Specifically, the process of determining the predicted pressure value of any one of the multiple sampling points under leak-free conditions can be implemented in the following way:

[0071] Based on the measured temperature value of the sampling point, and the measured pressure value and measured temperature value of the first sampling point among multiple sampling points, the predicted pressure value of the sampling point under leak-free operating conditions is determined.

[0072] The multiple sampling points are arranged in chronological order of sampling time.

[0073] Specifically, the sampling point is taken as the sampling point corresponding to time t in formula (5), and the first sampling point is taken as the sampling point corresponding to time t-1 in formula (5). That is, the measured temperature value of the sampling point is taken as... The measured pressure value of the first sampling point is taken as... The measured temperature value of the first sampling point is taken as Substituting into formula (5), the predicted pressure value of the sampling point under leak-free conditions can be calculated.

[0074] In this embodiment, the predicted pressure value of the sampling point under leak-free conditions is predicted based on the temperature change of the sampling point relative to the first sampling point, thus ensuring the accuracy of the predicted pressure value of the sampling point under leak-free conditions.

[0075] Among them, any one of the multiple preset volumes can be a fixed value or a range. The specific setting can be determined according to the actual application needs. This embodiment does not limit this.

[0076] In this step, when the preset volume is a certain value, if the cavity volume of the gas meter is equal to the preset volume, then the micro-leakage standard deviation corresponding to the preset volume is used as the micro-leakage standard deviation of the gas meter.

[0077] When the preset volume is a range, if the gas meter's cavity volume is greater than or equal to the lower limit of this range and less than or equal to the upper limit of this range, then the micro-leakage standard deviation corresponding to the preset volume will be used as the micro-leakage standard deviation of the gas meter.

[0078] S202. For any sampling point among multiple sampling points, determine whether the sampling point meets the micro-leakage condition based on the standard deviation of the gas meter's micro-leakage and the sampling information of the sampling point. If multiple sampling points meet the micro-leakage condition, then it is determined that there is a gas micro-leakage in the gas meter.

[0079] Among them, the micro-leakage condition is used to determine whether the measured pressure value at the sampling point is less than the pressure threshold and whether the rate of change of the measured pressure value at the sampling point relative to at least one sampling point before the sampling point is less than 0.

[0080] In this step, if each sampling point among multiple sampling points within a preset time period meets the micro-leakage condition, it indicates that within the preset time period, the measured pressure value of the gas meter is less than the pressure threshold and the measured pressure value is in a decreasing trend, then it can be determined that there is a micro-leakage of gas in the gas meter.

[0081] The micro-leakage conditions can be set according to the needs of actual applications, and this embodiment does not limit them. For example, the micro-leakage conditions can be: the measured pressure value of the sampling point is less than the pressure threshold, and the measured pressure value of the sampling point is less than the measured pressure value of the previous sampling point.

[0082] The micro-leakage condition can also be: the measured pressure value at the sampling point is less than the pressure threshold, and the measured pressure value at the sampling point is less than the measured pressure value of the first sampling point among multiple sampling points. The multiple sampling points are ordered according to the chronological order of sampling time.

[0083] Micro-leakage conditions can also be: the measured pressure value at the sampling point is less than the pressure threshold, and the measured pressure value at the sampling point is less than the average of the measured pressure values ​​at multiple sampling points.

[0084] The specific value of the pressure threshold is determined based on the standard deviation of the gas meter's micro-leakage and the predicted pressure value of the sampling point under leak-free conditions.

[0085] In this embodiment, the sampling information of each sampling point among multiple sampling points of the gas meter within a preset time period is determined. The sampling information includes the measured pressure value and the predicted pressure value under leak-free conditions. Based on the gas meter's cavity volume, the micro-leakage standard deviation of the gas meter is determined from the micro-leakage standard deviations corresponding to multiple preset volumes. The cavity volume is determined based on the gas meter's cavity shape, upper limit of the measurement range, and gas meter dimensions. The sampling information includes the measured pressure value and the predicted pressure value under leak-free conditions. The micro-leakage standard deviation of the gas meter is used to measure... The degree of fluctuation of the residual between the predicted pressure value and the measured pressure value of the gas meter under micro-leakage conditions; for any sampling point among multiple sampling points, based on the micro-leakage standard deviation of the gas meter and the sampling information of the sampling point, it is determined whether the sampling point meets the micro-leakage condition. It can accurately determine whether the measured pressure value of the sampling point deviates from the allowable range of the predicted pressure value under the leak-free condition. If multiple sampling points meet the micro-leakage condition, it means that each sampling point within the preset time period deviates from the allowable range of the corresponding predicted pressure value under the leak-free condition. Then it is determined that there is a gas micro-leakage in the gas meter, thereby realizing the detection of gas micro-leakage and improving the safety of gas use.

[0086] Figure 3 This is a flowchart illustrating the process of determining the cavity volume according to an embodiment of this application. In an optional implementation, the process of determining the cavity volume of the gas meter in S201 can be implemented in the following way:

[0087] S301. Based on the shape of the gas meter cavity, determine the target linear model corresponding to the cavity shape from multiple preset linear models.

[0088] In this embodiment, different cavity shapes correspond to different linear models. The preset shapes may include, but are not limited to, rectangular cubes and cylinders. The preset shapes and their corresponding linear models can be set according to the needs of actual applications; this embodiment does not impose any limitations on this.

[0089] In this step, if the gas meter cavity shape is a preset shape, then the linear model corresponding to the preset shape is used as the target linear model corresponding to the cavity shape.

[0090] S302. Based on the upper limit of the gas meter's measurement range and size information, determine the corresponding volume conversion factor for the gas meter using the target linear model.

[0091] The dimensions of the gas meter include its length, width, and height.

[0092] It should be noted that although gas meters have length, width, and height, this does not mean that the gas meter is rectangular in shape. The length, width, and height can be obtained from the gas meter's manufacturing information.

[0093] In practical applications, different gas meters typically have different measurement ranges. If the measurement range of a gas meter is [a cubic meters / hour, b cubic meters / hour], then the upper limit of the gas meter's measurement range is b cubic meters / hour.

[0094] In this step, the upper limit of the gas meter's measurement range, as well as the length, width, and height of the gas meter, are input into the target linear model. After calculation by the target linear model, the corresponding volume conversion coefficient of the gas meter is obtained.

[0095] S303. Determine the volume of the gas meter cavity based on the shape of the gas meter cavity, the upper limit of the measurement range, the size information, and the volume conversion factor.

[0096] In this step, different cavity shapes can correspond to different volume calculation formulas.

[0097] Optionally, if the cavity shape is a rectangular cube, the product of the upper limit of the measurement range, the length, width, height in the size information, and the volume conversion factor is used as the cavity volume.

[0098] Specifically, if the cavity shape is a rectangular cube, the cavity volume of the gas meter can be calculated using the following formula (7):

[0099] (7)

[0100] in, This indicates the volume of the gas meter's cavity, which is a rectangular cube. This represents the volume conversion factor for gas meters with a rectangular or cubic cavity shape. This indicates the upper limit of the gas meter's measurement range. This indicates the volume of the gas meter.

[0101] It should be noted that the gas meter has a certain size. It is the product of the length, width, and height of the gas meter.

[0102] In practical applications, the cavity shape of a diaphragm gas meter is usually approximately a rectangular cube. Here, the cavity shape of the approximately rectangular cube can be regarded as a rectangular cube, and the cavity volume of the diaphragm gas meter with the cavity shape approximately a rectangular cube can be calculated using the aforementioned formula (7).

[0103] Optionally, if the cavity is cylindrical, the cavity volume is the product of the upper limit of the measurement range, pi, length, width, height and volume conversion factor in the dimension information.

[0104] Specifically, if the cavity shape is cylindrical, the cavity volume of the gas meter can be calculated using the following formula (8):

[0105] (8)

[0106] in, This indicates the volume of the cavity in a gas meter with a cylindrical shape. This refers to the volume conversion factor for gas meters with a cylindrical cavity. Represents pi (π). This indicates the upper limit of the gas meter's measurement range. This indicates the volume of the gas meter.

[0107] It should be noted that the gas meter has a certain size. It is the product of the length, width, and height of the gas meter.

[0108] In practical applications, the cavity shape of an ultrasonic gas meter is usually approximately cylindrical. Here, the approximately cylindrical cavity shape can be regarded as a cylinder. Therefore, the cavity volume of the ultrasonic gas meter with an approximately cylindrical cavity shape can be calculated using the aforementioned formula (8).

[0109] In this embodiment, different volume calculation formulas are used to calculate the cavity volume for gas meters with different cavity shapes, making the cavity volume calculation more targeted and improving the accuracy of the cavity volume.

[0110] In this embodiment, different linear models are used to calculate the volume conversion factor of the gas meter for gas meters with different cavity shapes, making the calculation of the volume conversion factor more targeted and improving the accuracy of the volume conversion factor, thereby improving the accuracy of the cavity volume.

[0111] Figure 4 This is a flowchart illustrating the construction process of a linear model corresponding to a preset shape, as provided in an embodiment of this application. In an optional implementation, the construction process of the linear model corresponding to any preset shape in step S301 can be implemented in the following manner:

[0112] S401. Determine the initial linear model corresponding to the preset shape based on the preset shape.

[0113] In this step, different preset shapes can correspond to different initial linear models.

[0114] Optionally, if the preset shape is a rectangular cube, the initial linear model corresponding to the rectangular cube can be expressed as the following formula (9):

[0115] (9)

[0116] in, , and These are the parameters of the initial linear model corresponding to the rectangular cube. In subsequent steps, these three parameters are optimized to obtain the linear model corresponding to the rectangular cube.

[0117] Optionally, if the preset shape is a cylinder, the initial linear model corresponding to the cylinder can be expressed as the following formula (10):

[0118] (10)

[0119] in, , and These are the parameters of the initial linear model corresponding to the cylinder. In subsequent steps, these three parameters are optimized to obtain the linear model corresponding to the cylinder.

[0120] S402. For any target gas meter among multiple target gas meters with a preset cavity shape, based on the upper limit of the measurement range and size information of the target gas meter, and based on the initial linear model corresponding to the preset shape, determine the predicted volume conversion factor of the target gas meter, and based on the measurement cavity volume, upper limit of the measurement range and size information of the target gas meter, determine the actual volume conversion factor of the target gas meter.

[0121] The measurement chamber volume of the target gas meter refers to the actual chamber volume of the target gas meter obtained through actual measurement.

[0122] In this step, for any one of multiple target gas meters with a preset cavity shape, the volume of the target gas meter is calculated using its size information. The volume and upper limit of the measurement range of the target gas meter are then input into the initial linear model corresponding to the preset shape to predict the volume conversion factor of the target gas meter, thus obtaining the predicted volume conversion factor. Based on the measurement cavity volume, upper limit of the measurement range, and the volume of the gas meter, and using the cavity volume calculation formula corresponding to the target gas meter, the actual volume conversion factor of the target gas meter can be derived.

[0123] Optionally, if the preset shape is a rectangular cube, the volume of the target gas meter and the upper limit of the measurement range are substituted into the aforementioned formula (9) to calculate the predicted volume conversion factor of the target gas meter; the volume of the measuring chamber of the target gas meter, the upper limit of the measurement range and the volume of the gas meter are substituted into the aforementioned formula (7) to calculate the actual volume conversion factor of the gas meter.

[0124] Optionally, if the preset shape is a cylinder, the volume of the target gas meter and the upper limit of the measurement range are substituted into the aforementioned formula (10) to calculate the predicted volume conversion factor of the target gas meter; the volume of the measuring chamber of the target gas meter, the upper limit of the measurement range and the volume of the gas meter are substituted into the aforementioned formula (8) to calculate the actual volume conversion factor of the gas meter.

[0125] S403. Based on the predicted volume conversion coefficient and the actual volume conversion coefficient of each target gas meter in multiple target gas meters, optimize the initial linear model corresponding to the preset shape using the least squares method to obtain the linear model corresponding to the preset shape.

[0126] Specifically, for any target gas meter, the sum of squared errors between the predicted volume conversion factor and the actual volume conversion factor of the target gas meter is calculated to obtain the sum of squared errors corresponding to the target gas meter. The sums of squared errors corresponding to each target gas meter are then added together to obtain the total sum of squared errors. Based on the least squares method, the total sum of squared errors is minimized, thereby solving for a set of model parameters that minimizes the total sum of squared errors, thus obtaining the linear model corresponding to the preset shape.

[0127] Alternatively, if the preset shape is a rectangular cube, the sum of the squared errors can be expressed as the following formula (11):

[0128] (11)

[0129] in, This represents the sum of the squared errors corresponding to the target gas meter. This represents the predicted volume conversion factor corresponding to the i-th target gas meter. represents the actual volume conversion factor corresponding to the i-th target gas meter, and N represents the total number of target gas meters.

[0130] in, .in, This represents the upper limit of the measurement range of the i-th target gas meter. This represents the volume of the i-th target gas meter.

[0131] Based on the least squares method, the sum of squared errors By minimizing, we can obtain the parametric solution of the model parameters, which is shown in the following formula (12):

[0132] (12)

[0133] in, , and These are all model parameters for the linear model corresponding to the rectangular cube.

[0134] in, for , and The matrix formed by the coefficients of these three model parameters under various target gas meters. It can be expressed as the following formula (13):

[0135] (13)

[0136] This is a vector formed based on the conversion factors of the actual volume of each target gas meter. It can be expressed as the following formula (14):

[0137] (14)

[0138] Alternatively, if the preset shape is a cylinder, the sum of the squares of the errors can be expressed as the following formula (15):

[0139] (15)

[0140] in, This represents the sum of the squared errors corresponding to the target gas meter. This represents the predicted volume conversion factor corresponding to the i-th target gas meter. represents the actual volume conversion factor corresponding to the i-th target gas meter, and N represents the total number of target gas meters.

[0141] in, .in, This represents the upper limit of the measurement range of the i-th target gas meter. This represents the volume of the i-th target gas meter.

[0142] Based on the least squares method, the sum of squared errors By minimizing, we can obtain the parametric solution of the model parameters, which is shown in the following formula (16):

[0143] (16)

[0144] in, , and These are all model parameters for the linear model corresponding to the cylinder.

[0145] in, for , and The matrix formed by the coefficients of these three model parameters under various target gas meters. It can be expressed as the following formula (17):

[0146] (17)

[0147] This is a vector formed based on the conversion factors of the actual volume of each target gas meter. It can be expressed as the following formula (18):

[0148] (18)

[0149] In this embodiment, different initial linear models are defined for different preset shapes, and the predicted volume conversion factor and the actual volume conversion factor of the target gas meter with cavity shape as preset shape are used to optimize the initial linear model corresponding to the preset shape, thereby obtaining the linear model corresponding to the preset shape and improving the accuracy of the linear model corresponding to the preset shape.

[0150] Figure 5 This is a flowchart illustrating the process for determining the standard deviation of microleakage corresponding to a preset volume, as provided in an embodiment of this application. In an optional implementation, the process for determining the standard deviation of microleakage corresponding to any preset volume in step S201 can be implemented as follows:

[0151] S501. Determine the pressure prediction model under micro-leakage conditions; wherein, the pressure prediction model under micro-leakage conditions is used to predict the pressure value of the sampling point at the second time based on the measured pressure value and measured temperature value of the sampling point at the first time, and the pressure value at the first time is less than that at the second time.

[0152] Specifically, the pressure prediction model under micro-leakage conditions can be expressed as the aforementioned formula (6).

[0153] Here, time t-1 is the first time, and time t is the second time.

[0154] S502. For any target sampling point among multiple target sampling points of a gas meter with a preset cavity volume during a historical period under micro-leakage conditions, a pressure prediction model is used to predict the pressure value at the time of the target sampling point to obtain the predicted pressure value of the target sampling point. Based on the predicted pressure value and the measured pressure value of the target sampling point, the optimized predicted pressure value corresponding to the target sampling point is obtained using the Kalman filter algorithm.

[0155] The historical time period can be set according to the needs of actual application, and this embodiment does not limit it. The measured pressure value of the target sampling point refers to the actual pressure value obtained by measuring the gas pressure inside the gas meter cavity at the time of the sampling point through the pressure sensor of the gas meter.

[0156] In this step, for any target sampling point, the sampling point whose sampling time is earlier than the target sampling point (e.g., the first sampling point) is taken as the sampling point at time t-1, and the target sampling point is taken as the sampling point at time t. The measured pressure and temperature values ​​of the sampling point at time t-1, and the measured temperature value of the sampling point at time t, are input into the pressure prediction model under micro-leakage conditions to predict the pressure value of the sampling point at time t, thus obtaining the predicted pressure value of the target sampling point.

[0157] Furthermore, based on the predicted pressure value and the measured pressure value of the target sampling point, the predicted pressure value of the target sampling point is optimized using Kalman filtering to obtain the optimized predicted pressure value corresponding to the target sampling point. Specifically, the predicted pressure value of the target sampling point is optimized using the following formula (19):

[0158] (19)

[0159] in, This represents the optimized predicted pressure value corresponding to the target sampling point. The predicted pressure value for the target sampling point. Indicates Kalman gain, This indicates the measured pressure value at the target sampling point. This represents the observation matrix.

[0160] S503. Based on the measured pressure value of each target sampling point among multiple target sampling points and the corresponding optimized predicted pressure value, determine the micro-leakage standard deviation corresponding to the preset volume.

[0161] Specifically, for any target sampling point among multiple target sampling points, the difference between the measured pressure value of the target sampling point and the corresponding optimized predicted pressure value is used as the micro-leakage residual corresponding to the target sampling point.

[0162] Among them, the micro-leakage residual is used to measure the difference between the measured pressure value at the target sampling point and the optimized predicted pressure value.

[0163] Specifically, for any target sampling point, the difference between the measured pressure value and the corresponding optimized predicted pressure value is the micro-leakage residual for that target sampling point. Thus, the micro-leakage residuals for each of the multiple target sampling points can be obtained.

[0164] Alternatively, the micro-leakage residual can also be the difference between the optimized predicted pressure value of the target sampling point and the measured pressure value of the target sampling point.

[0165] Based on the micro-leakage residuals corresponding to each target sampling point in multiple target sampling points, determine the micro-leakage standard deviation corresponding to the preset volume.

[0166] Specifically, the standard deviation of microleakage corresponding to the preset volume is calculated using the following formula (20):

[0167] (20)

[0168] in, This represents the standard deviation of microleakage corresponding to the preset volume, and n represents the total number of target sampling points. This represents the micro-leakage residual corresponding to the i-th target sampling point. This represents the average value of the micro-leakage residuals corresponding to n target sampling points.

[0169] In this embodiment, the measured pressure value of the target sampling point is subtracted from the corresponding optimized predicted pressure value to obtain the micro-leakage residual. Based on the micro-leakage residual corresponding to each target sampling point, the micro-leakage standard deviation corresponding to the micro-leakage residual is calculated, so that the micro-leakage standard deviation can accurately measure the degree of fluctuation of the residual between the measured pressure value of the target sampling point and the corresponding optimized predicted pressure value.

[0170] In this embodiment, after predicting the pressure value of the target sampling point using the pressure prediction model under micro-leakage conditions and obtaining the predicted pressure value, the measured pressure value of the target sampling point is used to optimize the predicted pressure value based on the Kalman filter algorithm, thereby obtaining the optimized predicted pressure value and improving the accuracy of the predicted pressure value.

[0171] Alternatively, the microleakage standard deviation corresponding to the preset volume can be determined directly based on the measured pressure values ​​of each sampling point among multiple target sampling points and the predicted pressure value obtained using the pressure prediction model under microleakage conditions. For any target sampling point among multiple target sampling points, the difference between the measured pressure value and the predicted pressure value of the target sampling point is taken as the microleakage residual corresponding to the target sampling point. Thus, the microleakage residuals corresponding to each target sampling point among multiple target sampling points can be obtained. Based on the microleakage residuals corresponding to each target sampling point among multiple target sampling points, the microleakage standard deviation corresponding to the preset volume is determined. The implementation principle is the same as the implementation principle of S503 mentioned above, and will not be repeated here.

[0172] Figure 6This is a flowchart illustrating a method for determining whether a gas meter has a micro-leakage, provided in an embodiment of this application. In an optional implementation, in step S202, for any one of multiple sampling points, the method determines whether the sampling point meets the micro-leakage condition based on the micro-leakage standard deviation and the sampling information of the sampling point. If multiple sampling points meet the micro-leakage condition, then it is determined that the gas meter has a micro-leakage. This can be achieved in the following way:

[0173] S601. For any sampling point among multiple sampling points, determine the pressure threshold of the sampling point based on the standard deviation of the micro-leakage of the gas meter and the predicted pressure value of the sampling point under leak-free conditions.

[0174] Specifically, the product of the preset confidence coefficient and the standard deviation of the gas meter's micro-leakage is used as the error tolerance, and the difference between the predicted pressure value of the sampling point under leak-free conditions and the error tolerance is used as the pressure threshold of the sampling point.

[0175] The pressure threshold at the sampling point can be calculated using the following formula (21):

[0176] (twenty one)

[0177] in, Indicates the pressure threshold at the sampling point. This represents the predicted pressure value at the sampling point under leak-free operating conditions. This indicates the preset reliability coefficient. This represents the standard deviation of micro-leakage in the gas meter. This indicates the tolerance for error.

[0178] The preset confidence coefficient can be set according to the needs of the actual application, and this embodiment does not limit it. For example, the preset confidence coefficient can be 1, 2 or 3.

[0179] S602. If the measured pressure value at the sampling point is less than the pressure threshold of the sampling point, and the measured pressure value at the sampling point is less than the measured pressure value of the previous sampling point, then the sampling point is determined to meet the micro-leakage condition.

[0180] Specifically, if the measured pressure value at the sampling point is less than the pressure threshold of the sampling point, and the measured pressure value at the sampling point is less than the measured pressure value of the previous sampling point, it indicates that the measured pressure value at the sampling point exceeds the fluctuation range of the predicted pressure value under leak-free conditions, and has decreased compared to the measured pressure value of the previous sampling point. Therefore, it can be determined that the sampling point meets the micro-leakage condition.

[0181] S603. If multiple sampling points meet the micro-leakage condition, then it is determined that there is a micro-leakage of gas in the gas meter.

[0182] Specifically, if multiple sampling points meet the micro-leakage condition, it means that within a preset time period, the change in gas pressure inside the gas meter's cavity exceeds the range of gas pressure fluctuations under leak-free conditions, and the gas pressure inside the cavity is decreasing (i.e., the pressure change rate at the sampling point is less than 0). In this case, it can be determined that there is a micro-leakage in the gas meter.

[0183] It should be noted that, when determining whether the first sampling point among multiple sampling points meets the micro-leakage condition, since the measured pressure value of the preceding sampling point is unavailable, it is impossible to determine whether the first sampling point meets the micro-leakage condition. Therefore, it is unnecessary to determine whether the first sampling point meets the micro-leakage condition here.

[0184] In this embodiment, for any sampling point, the pressure threshold of the sampling point is determined based on the standard deviation of the micro-leakage of the gas meter and the predicted pressure value of the sampling point under leak-free conditions, thus accurately determining the lower limit of the pressure fluctuation range under leak-free conditions. If the measured pressure value of the sampling point is less than the pressure threshold of the sampling point and less than the measured pressure value of the previous sampling point, then the sampling point is determined to meet the micro-leakage condition. If multiple sampling points meet the micro-leakage condition, then the gas meter is determined to have a gas micro-leakage, so that the gas micro-leakage detection result refers to the sampling results over a period of time, improving the accuracy and reliability of micro-leakage detection.

[0185] Figure 7 This is a flowchart illustrating a method for determining a preset duration provided in an embodiment of this application. In one optional implementation, the preset duration can be set in the following way:

[0186] S701. Based on the cavity volume of the gas meter, determine the micro-leakage constant corresponding to the gas meter from multiple preset micro-leakage constants; wherein, the micro-leakage constant is used to measure the magnitude of the micro-leakage rate and is inversely proportional to the cavity volume.

[0187] Among the multiple preset volumes, the preset volume can be a fixed value or a range, and can be set according to the actual application needs. This embodiment does not limit this.

[0188] In this step, when the preset volume is a certain value, if the cavity volume of the gas meter is equal to the preset volume, then the micro-leakage constant corresponding to the preset volume is used as the micro-leakage constant of the gas meter.

[0189] When the preset volume is a range, if the gas meter's cavity volume is greater than or equal to the lower limit of this range and less than or equal to the upper limit of this range, then the micro-leakage constant corresponding to the preset volume will be used as the gas meter's micro-leakage constant.

[0190] S702. Determine the preset duration based on the micro-leakage constant corresponding to the gas meter; where the smaller the micro-leakage constant, the longer the preset duration.

[0191] Specifically, multiple micro-leakage constants corresponding to multiple preset volumes are sorted in ascending order of micro-leakage constant, and a longer preset duration is assigned to the micro-leakage constants that are ranked higher, while a shorter preset duration is assigned to the micro-leakage constants that are ranked lower.

[0192] The smaller the micro-leakage constant of the gas meter, the larger the volume of the gas meter cavity. When a micro-leak occurs in the gas meter, the greater the micro-leakage rate. This means that it takes longer to observe and determine whether there is a micro-leak in the gas meter. Therefore, the longer the preset time is set, the better.

[0193] In this embodiment, the micro-leakage constant of the gas meter is determined based on the cavity volume of the gas meter, and the preset sampling duration is set based on the micro-leakage constant of the gas meter, thereby improving the reliability of the sampling time.

[0194] In one optional implementation, the process of determining the micro-leakage constant corresponding to any preset volume in S701 can be implemented in the following way:

[0195] For any reference sampling point among multiple reference sampling points of a gas meter with a preset cavity volume within a preset time period under micro-leakage conditions, the sub-micro-leakage constant corresponding to the reference sampling point is determined based on the measured pressure value of the reference sampling point, as well as the measured pressure value and measured temperature value of the previous reference sampling point.

[0196] Specifically, for any reference sampling point, the sub-micro leakage constant corresponding to the reference sampling point is solved using the following formula (22):

[0197] (twenty two)

[0198] in, This represents the sub-micro-leakage constant corresponding to the reference sampling point. This indicates the measured pressure value at the reference sampling point. This indicates the measured pressure value of the previous reference sampling point. This indicates the measured temperature value of the previous reference sampling point. This indicates the measured temperature value at the reference sampling point. Indicates the sampling time of the reference sampling point. This indicates the sampling time of the previous reference sampling point.

[0199] The reference sampling points are arranged in chronological order of sampling time.

[0200] Based on the sub-micro-leakage constants corresponding to each of the multiple reference sampling points, the micro-leakage constant corresponding to the preset volume is determined.

[0201] Specifically, the average, median, or mode of the sub-micro-leakage constants corresponding to each reference sampling point are used as the micro-leakage constants corresponding to the preset volume.

[0202] In this embodiment, for any one of the multiple reference sampling points under micro-leakage conditions, the sub-micro-leakage constant corresponding to the reference sampling point is deduced by using the measured pressure and temperature values ​​of the reference sampling point, and the final micro-leakage constant is determined based on the multiple sub-micro-leakage constants, thus ensuring the accuracy of the micro-leakage constant and improving its reliability.

[0203] Figure 8 This is a schematic diagram of a gas micro-leakage detection device provided in an embodiment of this application. Figure 8 As shown, the gas micro-leakage detection device 800 includes: a micro-leakage standard deviation determination module 801 and a gas micro-leakage determination module 802.

[0204] The micro-leakage standard deviation determination module 801 is used to determine the sampling information of each sampling point among multiple sampling points of the gas meter within a preset time period, and to determine the micro-leakage standard deviation of the gas meter from the micro-leakage standard deviations corresponding to multiple preset volumes based on the gas meter's cavity volume.

[0205] The gas micro-leakage determination module 802 is used to determine whether a sampling point meets the micro-leakage condition based on the micro-leakage standard deviation and the sampling information of the sampling point among multiple sampling points. If multiple sampling points meet the micro-leakage condition, it is determined that there is a gas micro-leakage in the gas meter.

[0206] The cavity volume is determined based on the cavity shape of the gas meter, the upper limit of the measurement range, and the size information of the gas meter. The micro-leakage standard deviation of the gas meter is used to measure the degree of fluctuation of the residual between the predicted pressure value and the measured pressure value of the gas meter under micro-leakage conditions. The sampling information of the sampling point includes the measured pressure value of the sampling point and the predicted pressure value of the sampling point under leak-free conditions.

[0207] In one alternative implementation, during the process of determining the cavity volume, the microleakage standard deviation determination module 801 is also used for:

[0208] Based on the cavity shape, a target linear model corresponding to the cavity shape is determined from multiple preset linear models; based on the upper limit of the measurement range and size information, the volume conversion factor corresponding to the gas meter is determined based on the target linear model; and the cavity volume is determined based on the cavity shape, upper limit of the measurement range, size information, and volume conversion factor.

[0209] In one alternative implementation, during the construction of a linear model corresponding to any preset shape, the micro-leakage standard deviation determination module 801 is further used for:

[0210] Based on the preset shape, an initial linear model corresponding to the preset shape is determined. For any target gas meter among multiple target gas meters with a cavity shape of the preset shape, based on the upper limit of the measurement range and size information of the target gas meter, the predicted volume conversion factor of the target gas meter is determined based on the initial linear model. Based on the measurement cavity volume, upper limit of the measurement range, and size information of the target gas meter, the actual volume conversion factor of the target gas meter is determined. Based on the predicted volume conversion factor and actual volume conversion factor of each target gas meter among multiple target gas meters, the initial linear model is optimized based on the least squares method to obtain the linear model corresponding to the preset shape.

[0211] In one alternative implementation, when determining the cavity volume based on the cavity shape, upper limit of the measurement range, dimensional information, and volume conversion factor, the microleakage standard deviation determination module 801 is specifically used for:

[0212] If the cavity is a rectangular cube, the volume is the product of the upper limit of the measurement range, the length, width, height in the dimension information, and the volume conversion factor; or, if the cavity is a cylinder, the volume is the product of the upper limit of the measurement range, pi, the length, width, height in the dimension information, and the volume conversion factor.

[0213] In one optional implementation, when determining the micro-leakage standard deviation corresponding to any preset volume, the micro-leakage standard deviation determination module 801 is further configured to:

[0214] A pressure prediction model for micro-leakage conditions is established. This model predicts the pressure value at a sampling point at a second time step based on the measured pressure and temperature values ​​at the sampling point at a first time step, where the pressure at the first time step is less than that at the second time step. For any target sampling point among multiple target sampling points with a preset cavity volume within a historical period, the pressure prediction model is used to predict the pressure value at the target sampling point at that time, obtaining the predicted pressure value. Based on the predicted and measured pressure values ​​of the target sampling point, an optimized predicted pressure value is obtained using a Kalman filter algorithm. Finally, the standard deviation of the micro-leakage corresponding to the preset volume is determined based on the measured pressure values ​​and the corresponding optimized predicted pressure values ​​of each target sampling point.

[0215] In one optional implementation, when determining the microleakage standard deviation corresponding to a preset volume based on the measured pressure value of each target sampling point among multiple target sampling points and the corresponding optimized predicted pressure value, the microleakage standard deviation determination module 801 is specifically used for:

[0216] For any target sampling point among multiple target sampling points, the difference between the measured pressure value of the target sampling point and the corresponding optimized predicted pressure value is taken as the micro-leakage residual corresponding to the target sampling point; based on the micro-leakage residuals corresponding to each target sampling point among multiple target sampling points, the micro-leakage standard deviation corresponding to the preset volume is determined.

[0217] In one optional implementation, for any one of multiple sampling points, the system determines whether the sampling point meets the micro-leakage condition based on the micro-leakage standard deviation and the sampling information of the sampling point. If multiple sampling points meet the micro-leakage condition, then it is determined that there is a gas micro-leakage in the gas meter. Specifically, the gas micro-leakage determination module 802 is used for:

[0218] For any sampling point among multiple sampling points, the pressure threshold of the sampling point is determined based on the standard deviation of micro-leakage and the predicted pressure value of the sampling point under leak-free operating conditions. If the measured pressure value of the sampling point is less than the pressure threshold of the sampling point and the measured pressure value of the sampling point is less than the measured pressure value of the previous sampling point, then the sampling point is determined to meet the micro-leakage condition. If multiple sampling points meet the micro-leakage condition, then the gas meter is determined to have a gas micro-leakage.

[0219] In one alternative implementation, when determining the predicted pressure value of the sampling point under leak-free conditions, the micro-leakage standard deviation determination module 801 is also used for:

[0220] Based on the measured temperature value of the sampling point, and the measured pressure value and measured temperature value of the first sampling point among multiple sampling points, the predicted pressure value of the sampling point under leak-free operating conditions is determined.

[0221] In one alternative implementation, the gas micro-leakage determination module 802 is also used for:

[0222] Based on the cavity volume, the micro-leakage constant corresponding to the gas meter is determined from multiple preset volumes; the micro-leakage constant is used to measure the magnitude of the micro-leakage rate and is inversely proportional to the cavity volume; the preset duration is determined based on the micro-leakage constant; the smaller the micro-leakage constant, the longer the preset duration.

[0223] In one optional implementation, when determining the micro-leakage constant corresponding to any preset volume, the gas micro-leakage determination module 802 is further configured to:

[0224] For any reference sampling point among multiple reference sampling points of a gas meter with a cavity volume of a preset volume within a preset time period under micro-leakage conditions, the sub-micro-leakage constant corresponding to the reference sampling point is determined based on the measured pressure value of the reference sampling point, as well as the measured pressure value and measured temperature value of the previous reference sampling point; the micro-leakage constant corresponding to the preset volume is determined based on the sub-micro-leakage constants corresponding to each of the multiple reference sampling points.

[0225] The gas micro-leakage detection device provided in this embodiment can perform the method provided in the above method embodiment. Its implementation principle and technical effect are similar, and will not be described in detail here.

[0226] Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 9 As shown, the electronic device 900 includes a memory 901 and a processor 902. The memory 901 stores a computer program, and the processor 902 executes the computer program to implement the methods of any of the above embodiments. A communication link exists between the memory 901 and the processor 902. For example, the memory 901 and the processor 902 can communicate via a communication bus 903.

[0227] Optionally, the aforementioned processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps in the method embodiments disclosed in this application can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0228] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the methods in any of the above method embodiments.

[0229] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the methods in any of the above method embodiments.

[0230] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0231] The order of the embodiments described above is merely for illustrative purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, some processes described in the above embodiments and accompanying drawings include multiple operations appearing in a specific order; however, it should be clearly understood that these operations may not be executed in the order they appear herein or may be executed in parallel. The sequence numbers are merely used to distinguish different operations, and the sequence numbers themselves do not represent any execution order.

[0232] Furthermore, these processes may include more or fewer operations, and these operations may be executed sequentially or in parallel. It should be noted that the terms "first," "second," etc., used in this document are used to distinguish different messages, devices, modules, etc., and do not represent a chronological order, nor do they limit "first" and "second" to different types. "Multiple" means two or more, unless otherwise explicitly specified.

[0233] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0234] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

[0235] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for detecting micro-leaks in natural gas, characterized in that, include: The sampling information of each sampling point among multiple sampling points of the gas meter within a preset time period is determined, and the micro-leakage standard deviation of the gas meter is determined from the micro-leakage standard deviations corresponding to multiple preset volumes based on the gas meter cavity volume. For any of the multiple sampling points, it is determined whether the sampling point meets the micro-leakage condition based on the micro-leakage standard deviation of the gas meter and the sampling information of the sampling point. If all of the multiple sampling points meet the micro-leakage condition, it is determined that there is a gas micro-leakage in the gas meter. The cavity volume is determined based on the cavity shape, upper limit of the measurement range, and size information of the gas meter. The micro-leakage standard deviation of the gas meter is used to measure the degree of fluctuation of the residual between the predicted pressure value and the measured pressure value of the gas meter under micro-leakage conditions. The sampling information of the sampling point includes the measured pressure value of the sampling point and the predicted pressure value of the sampling point under leak-free conditions.

2. The method according to claim 1, characterized in that, The process of determining the volume of the cavity includes: Based on the cavity shape, a target linear model corresponding to the cavity shape is determined from multiple linear models corresponding to preset shapes; Based on the upper limit of the measurement range and the size information, and based on the target linear model, the volume conversion factor corresponding to the gas meter is determined; The volume of the cavity is determined based on the cavity shape, the upper limit of the measurement range, the size information, and the volume conversion factor.

3. The method according to claim 2, characterized in that, The process of constructing a linear model corresponding to any of the preset shapes includes: Based on the preset shape, determine the initial linear model corresponding to the preset shape; For any one of the multiple target gas meters with the cavity shape of the preset shape, based on the upper limit of the measurement range and size information of the target gas meter, the predicted volume conversion factor of the target gas meter is determined based on the initial linear model, and the actual volume conversion factor of the target gas meter is determined based on the measurement cavity volume, upper limit of the measurement range and size information of the target gas meter. Based on the predicted volume conversion factor and the actual volume conversion factor of each of the multiple target gas meters, the initial linear model is optimized using the least squares method to obtain the linear model corresponding to the preset shape.

4. The method according to claim 2, characterized in that, Determining the cavity volume based on the cavity shape, the upper limit of the measurement range, the size information, and the volume conversion factor includes: If the cavity shape is a rectangular cube, then the product of the upper limit of the measurement range, the length, width, and height in the size information, and the volume conversion factor is taken as the cavity volume; or, If the cavity is cylindrical, the volume of the cavity is the product of the upper limit of the measurement range, pi, the length, width, and height in the size information, and the volume conversion factor.

5. The method according to claim 1, characterized in that, The process of determining the standard deviation of microleakage corresponding to any of the preset volumes includes: A pressure prediction model is determined under micro-leakage conditions; wherein, the pressure prediction model is used to predict the pressure value of the sampling point at a second time based on the measured pressure value and measured temperature value of the sampling point at a first time moment, where the pressure value at the first time moment is less than that at the second time moment. For any target sampling point among multiple target sampling points of a gas meter with a cavity volume of the preset volume under micro-leakage conditions within a historical period, the pressure prediction model is used to predict the pressure value at the time of the target sampling point to obtain the predicted pressure value of the target sampling point. Based on the predicted pressure value of the target sampling point and the measured pressure value of the target sampling point, the optimized predicted pressure value corresponding to the target sampling point is obtained based on the Kalman filter algorithm. Based on the measured pressure value of each target sampling point among the multiple target sampling points and the corresponding optimized predicted pressure value, the micro-leakage standard deviation corresponding to the preset volume is determined.

6. The method according to claim 5, characterized in that, The step of determining the microleakage standard deviation corresponding to the preset volume based on the measured pressure value of each target sampling point among the plurality of target sampling points and the corresponding optimized predicted pressure value includes: For any target sampling point among the plurality of target sampling points, the difference between the measured pressure value of the target sampling point and the corresponding optimized predicted pressure value is taken as the micro-leakage residual corresponding to the target sampling point. The microleakage standard deviation corresponding to the preset volume is determined based on the microleakage residuals corresponding to each of the multiple target sampling points.

7. The method according to claim 1, characterized in that, For any one of the plurality of sampling points, the method of determining whether the sampling point meets the micro-leakage condition based on the micro-leakage standard deviation and the sampling information of the sampling point; if all the plurality of sampling points meet the micro-leakage condition, then it is determined that the gas meter has a gas micro-leakage, including: For any of the plurality of sampling points, the pressure threshold of the sampling point is determined based on the micro-leakage standard deviation and the predicted pressure value of the sampling point under leak-free conditions. If the measured pressure value at the sampling point is less than the pressure threshold of the sampling point, and the measured pressure value at the sampling point is less than the measured pressure value of the previous sampling point, then the sampling point is determined to meet the micro-leakage condition. If all of the sampling points meet the micro-leakage condition, then it is determined that there is a micro-leakage in the gas meter.

8. The method according to claim 1, characterized in that, The process of determining the predicted pressure value of the sampling point under leak-free operating conditions includes: Based on the measured temperature value of the sampling point, and the measured pressure value and measured temperature value of the first sampling point among the plurality of sampling points, the predicted pressure value of the sampling point under leak-free operating conditions is determined.

9. The method according to any one of claims 1-8, characterized in that, Also includes: Based on the cavity volume, the micro-leakage constant corresponding to the gas meter is determined from multiple preset micro-leakage constants; wherein, the micro-leakage constant is used to measure the magnitude of the micro-leakage rate and is inversely proportional to the cavity volume; The preset duration is determined based on the microleakage constant; wherein, the smaller the microleakage constant, the longer the preset duration.

10. The method according to claim 9, characterized in that, The process of determining the microleakage constant corresponding to any of the preset volumes includes: For any reference sampling point among multiple reference sampling points of a gas meter with a cavity volume of the preset volume within a preset time period under micro-leakage conditions, the sub-micro-leakage constant corresponding to the reference sampling point is determined based on the measured pressure value of the reference sampling point, as well as the measured pressure value and measured temperature value of the previous reference sampling point. The micro-leakage constant corresponding to the preset volume is determined based on the sub-micro-leakage constant corresponding to each of the plurality of reference sampling points.

11. A gas micro-leakage detection device, characterized in that, include: The micro-leakage standard deviation determination module is used to determine the sampling information of each sampling point among multiple sampling points of the gas meter within a preset time period, and to determine the micro-leakage standard deviation of the gas meter from the micro-leakage standard deviations corresponding to multiple preset volumes based on the cavity volume of the gas meter. The gas micro-leakage determination module is used to determine whether any of the multiple sampling points meets the micro-leakage condition based on the micro-leakage standard deviation and the sampling information of the sampling point. If all the multiple sampling points meet the micro-leakage condition, it is determined that there is a gas micro-leakage in the gas meter. The cavity volume is determined based on the cavity shape, upper limit of the measurement range, and size information of the gas meter. The micro-leakage standard deviation of the gas meter is used to measure the degree of fluctuation of the residual between the predicted pressure value and the measured pressure value of the gas meter under micro-leakage conditions. The sampling information of the sampling point includes the measured pressure value of the sampling point and the predicted pressure value of the sampling point under leak-free conditions.

12. An electronic device, characterized in that, include: Memory and processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory to implement the method as described in any one of claims 1-10.

13. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 1-10.

14. A computer program product, characterized in that, Includes a computer program that, when executed by a processor, implements the method of any one of claims 1-10.

Images