A cruise data-based methane leakage source category identification method and device

Abstract

The application provides a kind of methane leakage source category identification method and device based on cruise data.The method comprises the following steps: obtaining methane concentration data and ethane concentration data output by gas concentration sensor on cruise detection vehicle;Determine the methane concentration abnormal enhancement data section based on the size of methane concentration;Determine the methane leakage source category based on the relative size and correlation of methane concentration and ethane concentration in the data section, the category includes natural gas source, biogas source and uncertain gas source.The application realizes the tracing of methane leakage source by determining the methane concentration abnormal enhancement data section, not only lays the foundation for leakage source positioning, but also provides convenience for solving methane leakage problem from the root.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of natural gas leakage detection, and particularly relates to a methane leakage source category identification method and device based on cruise data. BACKGROUND

[0002] Methane is the second largest global greenhouse gas after carbon dioxide, with a 20-year and 100-year global warming potential of 82 times and 29.8 times that of CO2, respectively, and a contribution rate of 31% to the global net warming effect in fully mixed greenhouse gas emissions. Methane can also increase the tropospheric ozone through radiation and chemical effects, and further cause negative effects such as increased premature death, reduced food production, and weakened plant carbon sequestration capacity. Cities are an important source of methane emissions and a major platform for addressing greenhouse gas emissions and climate change. Urban methane emissions are mainly unorganized diffusion, with complex sources, low concentration, large fluctuations, and strong sporadicity. Existing research has found that the city gas transmission and distribution system has long pipelines and many pipe fittings, and is affected by subway stray current corrosion, land subsidence, etc. About 2.5±0.5% of the leaked gas enters the atmosphere, which is an important source of urban methane emissions. At the same time, the leaked natural gas will accumulate in the underground limited space and increase the risk of explosion, threatening urban public safety. How to identify the source of methane under complex background concentration is a key problem to be solved to determine the source of methane emission (mainly including natural gas source, biogas source and uncertain gas source) and promote greenhouse gas emission reduction.

[0003] Therefore, the present application provides a methane leakage source category identification method and device based on cruise data. SUMMARY

[0004] In order to solve the above problems existing in the prior art, the present application provides a methane leakage source category identification method and device based on cruise data.

[0005] In order to achieve the above purpose, the present application adopts the following technical solutions.

[0006] In the first aspect, the present application provides a methane leakage source category identification method based on cruise data, comprising the following steps:

[0007] Obtaining methane concentration data and ethane concentration data output by a gas concentration sensor on a cruise detection vehicle;

[0008] Determining a methane concentration abnormal enhancement data segment based on the size of the methane concentration;

[0009] Determining a methane leakage source category based on the relative size and correlation of the methane concentration and the ethane concentration in the data segment, the category including a natural gas source, a biogas source and an uncertain gas source.

[0010] Furthermore, the method for determining the abnormally enhanced methane concentration data segment includes:

[0011] Calculate the methane background concentration X0 based on the methane concentration data;

[0012] All consecutive methane concentration data points with more than N values ​​exceeding the first threshold are divided into an abnormally enhanced data segment; the first threshold = (1 + a%) × 0, where the value of a is determined based on industry experience.

[0013] Furthermore, the method for determining the type of methane leakage source includes:

[0014] S11. Calculate the methane enhancement ratio for each data point within the anomalously enhanced data segment:

[0015]

[0016] In the formula, R is the methane and ethane enhancement ratio, Y0 is the ethane background concentration, and X and Y are the methane and ethane concentrations corresponding to the data points in the abnormally enhanced data segment, respectively.

[0017] S12. If R is greater than the second threshold, proceed to S13; otherwise, proceed to S14.

[0018] S13. The correlation between methane concentration and ethane concentration is analyzed using the P-value of the P-test. If the P-value is less than 0.05, the correlation is considered significant, and the source of methane is natural gas; otherwise, the source of methane is an uncertain gas source.

[0019] S14. Check if the ethane concentration decreases at the peak methane concentration point. If so, the methane source is biogas; otherwise, the methane source is an uncertain gas source.

[0020] Furthermore, methods for calculating methane background concentration include:

[0021] S21. Set a first sliding time window and a second sliding time window with widths of 2n and 2m respectively, n <m;

[0022] S22. Calculate the median methane concentration B within the first sliding time window centered at time point t. tmp,t ;

[0023] S23. Calculate B for each time point within the first sliding time window centered at time t. tmp,t And calculate B for all points within the window. tmp,t Standard deviation BSD tmp,t ;

[0024] S24. Calculate the BSD within the second sliding time window centered at time point t. tmp,t The median MSD oftmp,t ;

[0025] S25, calculate the methane background concentration according to the following formula:

[0026]

[0027] In the formula, B t is the methane background concentration at time point t, obs t is the methane concentration measurement value or observation value at time point t, B tmp,t1 , B tmp,t2 are the B tmp,t values of the two endpoints of the time period satisfying the BSD tmp,t ≥ MSD tmp,t .

[0028] Further, the calculation method of the ethane background concentration comprises: calculating the median value of the ethane concentration in the abnormal enhancement data segment, and taking the median value as the ethane background concentration in the data segment.

[0029] In a second aspect, the present application provides a methane leakage source category identification device based on cruise data, comprising:

[0030] A data acquisition module is configured to acquire methane concentration data and ethane concentration data output by a gas concentration sensor on a cruise detection vehicle.

[0031] A data segmentation module is configured to determine a methane concentration abnormal enhancement data segment based on the size of the methane concentration.

[0032] A methane tracing module is configured to determine a methane leakage source category based on the relative size and correlation of the methane concentration and the ethane concentration in the data segment, wherein the category includes a natural gas source, a biogas source, and an uncertain gas source.

[0033] Further, the method for determining the methane concentration abnormal enhancement data segment comprises:

[0034] Calculating a methane background concentration X0 based on the methane concentration data;

[0035] Dividing all continuous N or more methane concentration data points greater than a first threshold value into an abnormal enhancement data segment respectively; the first threshold value = (1+a%)X0, and the size of a is determined according to industry experience.

[0036] Further, the method for determining the methane leakage source category comprises:

[0037] S11, calculating the methane-ethane enhancement ratio for the data points in each abnormal enhancement data segment:

[0038]

[0039] In the formula, R is the methane enhancement ratio, Y0 is the background concentration of ethane, X and Y are the methane concentration and ethane concentration of the data points in the abnormal enhancement data segment, respectively;

[0040] S12, if R is greater than the second threshold value, turn to S13; otherwise, turn to S14;

[0041] S13, analyze the correlation between the methane concentration and the ethane concentration by using the P value of the Pearson test, if the P value is less than 0.05, it is considered that the correlation is significant, and the methane source is a natural gas source; otherwise, the methane source is an uncertain gas source;

[0042] S14, check whether the ethane concentration decreases at the peak point of the methane concentration, if yes, the methane source is a biogas source; otherwise, the methane source is an uncertain gas source.

[0043] Further, the calculation method of the methane background concentration comprises:

[0044] S21, set a first sliding time window and a second sliding time window with widths of 2n and 2m respectively, n < m;

[0045] S22, calculate the median value B of the methane concentration in the first sliding time window centered at the t time point tmp,t ;

[0046] S23, calculate B of each time in the first sliding time window centered at the t time point tmp,t , and calculate the standard deviation BSD of B of all points in the window tmp,t ; tmp,t ;

[0047] S24, calculate the median MSD of BSD in the second sliding time window centered at the t time point tmp,t ; tmp,t ;

[0048] S25, calculate the methane background concentration according to the following formula:

[0049]

[0050] In the formula, B is the methane background concentration at the t time point, obs is the measured value or observation value of the methane concentration at the t time point, B and B are the B values of the two end points of the time segment satisfying BSD ≥ MSD. t t tmp,t1 tmp,t2 tmp,t tmp,t tmp,t

[0051] ​​​​​​​Further, the calculation method of the ethane background concentration comprises: calculating a median value of the ethane concentration in the abnormal enhanced data section, and taking the median value as the ethane background concentration in the data section.

[0052] Compared with the prior art, the present application has the following beneficial effects.

[0053] The present application realizes the tracing of the methane leakage source by acquiring the methane concentration data and the ethane concentration data output by the gas concentration sensor on the cruise detection vehicle, determining the methane concentration abnormal enhanced data section based on the size of the methane concentration, and determining the methane leakage source category based on the relative size and correlation of the methane concentration and the ethane concentration in the data section, wherein the category comprises a natural gas source, a biogas source and an uncertain gas source. The present application realizes the tracing of the methane leakage source by determining the methane concentration abnormal enhanced data section, which not only lays a foundation for the positioning of the leakage source, but also provides convenience for solving the methane leakage problem from the root. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 The flow chart of the embodiment of the present application is a methane leakage source category identification method based on cruise data.

[0055] Figure 2 The schematic diagram of the methane concentration abnormal enhanced data section is shown.

[0056] Figure 3 The schematic diagram of the first sliding time window and the second sliding time window is shown.

[0057] Figure 4 The block diagram of the embodiment of the present application is a methane leakage source category identification device based on cruise data. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical scheme and advantages of the present application clearer and more apparent, the present application is further described below in combination with the drawings and specific embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0059] Figure 1 The flow chart of the embodiment of the present application is a methane leakage source category identification method based on cruise data, which comprises the following steps:

[0060] Step 101, acquiring the methane concentration data and the ethane concentration data output by the gas concentration sensor on the cruise detection vehicle;

[0061] Step 102, determining the methane concentration abnormal enhanced data section based on the size of the methane concentration;

[0062] Step 103, determining the methane leakage source category based on the relative size and correlation of the methane concentration and ethane concentration in the data segment, the category including natural gas source, biogas source and uncertain gas source.

[0063] The embodiment provides a methane leakage source category identification method based on cruise data. The cruise data refers to data from a cruise detection vehicle. The cruise detection vehicle is equipped with a methane and ethane concentration sensor, an anemograph, a vehicle speed sensor and a data processing system and the like. The methane and ethane concentration sensor is used for measuring the methane gas concentration and the ethane gas concentration, the anemograph is used for measuring the wind speed of the vehicle, the vehicle speed sensor is used for measuring the vehicle speed, and the data processing system is used for identifying the methane leakage source category, i.e. tracing the source, by processing the methane and ethane concentration data and the wind speed data.

[0064] In the embodiment, step 101 is mainly used for obtaining the methane concentration data and the ethane concentration data. In the embodiment, the methane gas concentration and the ethane gas concentration in the detection environment are obtained from the methane and ethane concentration sensor on the cruise detection vehicle.

[0065] In the embodiment, step 102 is mainly used for determining the methane concentration abnormal enhancement data segment. The abnormal enhancement data refers to data that is obviously enhanced compared with normal data, and the reason for the abnormal enhancement of the methane concentration is very likely to be natural gas leakage. Therefore, determining the methane concentration abnormal enhancement data segment is the key to natural gas leakage detection, leakage source positioning and tracing. The methane concentration abnormal enhancement data segment is generally determined by comparing the methane concentration data with a set concentration threshold, and of course, the minimum number of data is generally limited to form a "data segment", so as to eliminate the influence of individual sharp pulse interference data. A specific technical solution for determining the abnormal enhancement data segment will be given in the following embodiment.

[0066] In the embodiment, step 103 is mainly used for determining the methane leakage source category. The methane leakage source category in the embodiment includes three categories, i.e. natural gas source, biogas source and uncertain gas source. The technical principle of the methane leakage source category in the embodiment is that the methane concentration distribution and the ethane concentration distribution have certain regularity in the above three leakage sources, and different leakage source categories have different specific forms. Therefore, the embodiment is aimed at the determined methane concentration abnormal enhancement data segment, and the methane leakage source category is determined according to the relative size and correlation of the methane concentration and the ethane concentration in the data segment.

[0067] As an optional embodiment, the method for determining the methane concentration abnormal enhancement data segment comprises:

[0068] calculating the methane background concentration X0 based on the methane concentration data;

[0069] All continuous N more than the first threshold methane concentration data points are divided into an abnormal enhancement data segment respectively; the first threshold = (1+a%)X0, the size of a is determined according to industry experience.

[0070] The embodiment gives a technical solution for determining the methane concentration abnormal enhancement data segment. The embodiment first determines whether the size of the methane concentration data exceeds the first threshold. For the methane concentration data points whose size exceeds the first threshold, it is checked whether there are N or more continuous data points. If there are, all such N or more continuous data points respectively form an abnormal enhancement data segment, such as data segments 1, 2 and 3 shown in the figure. Figure 2 The checking of the number of continuous data points is to eliminate the influence of transient interference pulses. Although the signal intensity exceeds the first threshold, the duration, i.e. the number of data occupied, is less than N because the transient interference pulse has the characteristics of strong amplitude and short duration. The size of the first threshold is generally relative to the methane background concentration X0. The first threshold is a% larger than the methane background concentration X0, i.e. the first threshold = (1+a%)X0. The size of a is determined according to industry experience. The methane background concentration mainly refers to the local environmental background concentration. There are certain differences in the methane background concentration in different regions (such as cities and mountainous areas). There are also differences in the local methane background concentration in residential areas and roads. The significance of setting the first threshold to be a certain percentage higher than the background concentration is to extract the specific signal exceeding the background concentration to carry out methane source identification and tracing work.

[0071] As an optional embodiment, the method for determining the methane leakage source category comprises:

[0072] S11, calculating the methane and ethane enhancement ratio for the data points in each abnormal enhancement data segment:

[0073]

[0074] In the formula, R is the methane and ethane enhancement ratio, Y0 is the ethane background concentration, and X and Y are the methane concentration and ethane concentration corresponding to the data points in the abnormal enhancement data segment, respectively;

[0075] S12, if R is greater than the second threshold, turn to S13; otherwise, turn to S14;

[0076] S13, using the P value of Pearson test to analyze the correlation between the methane concentration and the ethane concentration. If the P value is less than 0.05, it is considered that the correlation is significant, and the methane source is a natural gas source; otherwise, the methane source is an uncertain gas source.

[0077] S14, checking whether the ethane concentration decreases at the methane concentration peak point. If yes, the methane source is a biogas source; otherwise, the methane source is an uncertain gas source.

[0078] This embodiment provides a technical solution for determining the type of methane leak source. This embodiment is based on the data points within the abnormally enhanced data segment for processing and judgment. First, the methane and ethane enhancement ratio R is calculated. R is equal to the ratio of the difference between the observed methane concentration (i.e., the measured value) and the methane background concentration to the difference between the observed ethane concentration and the ethane background concentration, as shown in equation (1). Then, it is determined whether R is greater than the second threshold. If it is greater, it indicates that the leak source type may be natural gas or an uncertain source; if it is not greater, it indicates that the leak source type may be biogas or an uncertain source. This embodiment further determines whether it is a natural gas or an uncertain source based on the correlation between methane concentration and ethane concentration. Specifically, the P-value of the Pearson test is used to analyze the correlation between methane concentration and ethane concentration. If the P-value is less than 0.05, the correlation is considered significant, and the methane source is a natural gas source; otherwise, the methane source is an uncertain gas source. Since the ethane emission from the biogas source is relatively small, the ethane concentration will decrease at the peak of the methane concentration, which can be used to identify the biogas source. Specifically, in this embodiment, the methane concentration decreases at the peak methane concentration point to further determine whether it is a biogas source or an uncertain source. If the concentration decreases, the methane source is a biogas source; otherwise, the methane source is an uncertain gas source.

[0079] As an optional embodiment, the method for calculating the methane background concentration includes:

[0080] S21. Set a first sliding time window and a second sliding time window with widths of 2n and 2m respectively, n <m;

[0081] S22. Calculate the median methane concentration B within the first sliding time window centered at time point t. tmp,t ;

[0082] S23. Calculate B for each time point within the first sliding time window centered at time t. tmp,t And calculate B for all points within the window. tmp,t Standard deviation BSD tmp,t ;

[0083] S24. Calculate the BSD within the second sliding time window centered at time point t. tmp,t The median MSD of tmp,t ;

[0084] S25. Calculate the methane background concentration using the following formula:

[0085]

[0086] In the formula, B t Here, obs represents the background concentration of methane at time t. t B represents the measured or observed methane concentration at time t. tmp,t1 B tmp,t2 respectively satisfying BSDtmp,t ≥MSD tmp,t at both ends of the time period of tmp,t B value.

[0087] This embodiment provides a technical solution for calculating the methane background concentration. In this embodiment, a dual sliding time window is used to extract the methane background concentration. The dual sliding time window includes a first sliding time window and a second sliding time window with widths of 2n and 2m respectively, where n < m, as Figure 3 shown. Sometimes the first and second sliding time windows are also referred to as the sub-window and the main window respectively. First, calculate the observed median value within the first sliding time window at time point t, and use it as the initial value B of the background concentration tmp,t . Then calculate B at each time within the first sliding time window centered at time point t tmp,t , and calculate the standard deviation BSD tmp,t of all points of B within the window tmp,t , as well as the BSD tmp,t within the second sliding time window tmp,t . The standard deviation BSD tmp,t reflects the volatility of the background concentration and can be used to correct the overestimation of the background concentration under high backgrounds. Finally, calculate the background concentration (or correct the initial value of the background concentration) according to the magnitudes of BSD tmp,t and MSD tmp,t , and the calculation formula is as shown in formula (2). When BSD tmp,t is less than MSD tmp,t , it indicates that there is no significant local high value at this time point. Therefore, the initial background concentration BSD tmp,t is preferentially selected; however, if the initial background concentration value BSD tmp,t is greater than the observed value obs t , then the observed value obs t is directly used as the background concentration; when BSD tmp,t is greater than or equal to MSD tmp,t , it indicates that there may be a significant local high value in this area, and the initial background concentration may cause overestimation of the background concentration. Therefore, the average value of the B tmp,t values at both time endpoints of this time period ((B tmp,t1 +B tmp,t2 ) / 2) is used as the overall background concentration within this time period.

[0088] As an optional embodiment, the calculation method of the ethane background concentration includes: calculating the median value of the ethane concentration within the abnormal enhancement data segment, and using the median value as the ethane background concentration within the data segment.

[0089] The embodiment gives a technical solution for calculating the background concentration of ethane. Since ethane is mainly used for methane tracing in the embodiment, the median value in the observation can be used as the background concentration of ethane in the abnormal enhancement data segment, and the solving method of the relative methane background concentration is much simpler.

[0090] Figure 4 A component schematic diagram of a methane leakage source category identification device based on cruise data according to an embodiment of the application is shown in the figure. The device comprises:

[0091] A data acquisition module 11 is configured to acquire methane concentration data and ethane concentration data output by a gas concentration sensor on a cruise detection vehicle;

[0092] A data segmentation module 12 is configured to determine an abnormal enhancement data segment of methane concentration based on the size of the methane concentration;

[0093] A methane tracing module 13 is configured to determine a methane leakage source category based on the relative size and correlation of the methane concentration and the ethane concentration in the data segment, wherein the category includes a natural gas source, a biogas source and an uncertain gas source.

[0094] The device of the embodiment can be used to perform the method of the embodiment. Figure 1 The technical solution of the method embodiment is similar in implementation principle and technical effect, and will not be described here. The same applies to the following embodiments, which will not be described here.

[0095] As an optional embodiment, the method of determining the abnormal enhancement data segment of the methane concentration comprises:

[0096] calculating a methane background concentration X0 based on the methane concentration data;

[0097] dividing all continuous N or more methane concentration data points greater than a first threshold value into an abnormal enhancement data segment respectively; the first threshold value = (1+a%)X0, and the size of a is determined according to industry experience.

[0098] As an optional embodiment, the method of determining the methane leakage source category comprises:

[0099] S11, calculating the methane-ethane enhancement ratio for the data points in each abnormal enhancement data segment:

[0100]

[0101] In the formula, R is the methane-ethane enhancement ratio, Y0 is the background concentration of ethane, and X and Y are the methane concentration and ethane concentration corresponding to the data points in the abnormal enhancement data segment, respectively;

[0102] S12, if R is greater than a second threshold value, go to S13; otherwise, go to S14;

[0103] S13. The correlation between methane concentration and ethane concentration is analyzed using the P-value of the P-test. If the P-value is less than 0.05, the correlation is considered significant, and the source of methane is natural gas; otherwise, the source of methane is an uncertain gas source.

[0104] S14. Check if the ethane concentration decreases at the peak methane concentration point. If so, the methane source is biogas; otherwise, the methane source is an uncertain gas source.

[0105] As an optional embodiment, the method for calculating the methane background concentration includes:

[0106] S21. Set a first sliding time window and a second sliding time window with widths of 2n and 2m respectively, n <m;

[0107] S22. Calculate the median methane concentration B within the first sliding time window centered at time point t. tmp,t ;

[0108] S23. Calculate B for each time point within the first sliding time window centered at time t. tmp,t And calculate B for all points within the window. tmp,t Standard deviation BSD tmp,t ;

[0109] S24. Calculate the BSD within the second sliding time window centered at time point t. tmp,t The median MSD of tmp,t ;

[0110] S25. Calculate the methane background concentration using the following formula:

[0111]

[0112] In the formula, B t Here, obs represents the background concentration of methane at time t. t B represents the measured or observed methane concentration at time t. tmp,t1 B tmp,t2 respectively satisfying BSD tmp,t ≥MSD tmp,t B at the two endpoints of the time period tmp,t value.

[0113] As an optional embodiment, the method for calculating the ethane background concentration includes: calculating the median value of the ethane concentration within the abnormally enhanced data segment, and using the median value as the ethane background concentration within the data segment.

[0114] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for identifying a methane leak source category based on cruise data, the method comprising: The method comprises the following steps: Step 1, obtaining methane concentration data and ethane concentration data output by a gas concentration sensor on a cruise detection vehicle; Step 2, determining a methane concentration abnormally enhanced data segment based on the size of the methane concentration, comprising: calculating a methane background concentration X0 based on the methane concentration data; dividing all continuous N or more methane concentration data points greater than a first threshold value into an abnormally enhanced data segment respectively; the first threshold value = (1 + a%) X0, and the size of a is determined according to industry experience; Step 3, determining a methane leakage source category based on the relative size and correlation of the methane concentration and the ethane concentration in the data segment, the category comprising a natural gas source, a biogas source and an uncertain gas source; the method for determining the methane leakage source category comprises: S11, calculating a methane-ethane enhancement ratio for data points in each abnormally enhanced data segment: wherein R is the methane-ethane enhancement ratio, Y0 is the ethane background concentration, and X and Y are the methane concentration and the ethane concentration corresponding to the data points in the abnormally enhanced data segment respectively; S12, if R is greater than a second threshold value, turning to S13; otherwise, turning to S14; S13, analyzing the correlation of the methane concentration and the ethane concentration by using a P value of Pearson test, and if the P value is less than 0.05, considering that the correlation is significant, and the methane source is a natural gas source; otherwise, the methane source is an uncertain gas source; S14, checking whether the ethane concentration decreases at a methane concentration peak point, and if yes, the methane source is a biogas source; otherwise, the methane source is an uncertain gas source.

2. The cruise data based methane leak source category identification method of claim 1, wherein, The method for calculating the methane background concentration comprises: S21, setting a first sliding time window and a second sliding time window with widths of 2n and 2m respectively, wherein n < m; S22, calculate the methane concentration median value B in the first sliding time window centered on the t time point tmp,t ; S23, calculate B for each time within a first sliding time window centered at time point t tmp,t and calculate the standard deviation BSD of B for all points within the window tmp,t tmp,t ;​ S24, calculate the BSD within a second sliding time window centered at the t time point tmp,t median MSD of the tmp,t ; S25, calculating the methane background concentration according to the following formula: where B t is the methane background concentration at time point t, obs t is the methane concentration measurement or observation at time point t, B tmp,t1 , B tmp,t2 are the B tmp,t values at the two endpoints of the time period that satisfy the BSD tmp,t ≥ MSD tmp,t , respectively.

3. The cruise data based methane leak source category identification method of claim 2, wherein, The method for calculating the ethane background concentration comprises: calculating a median value of the ethane concentration in the abnormally enhanced data segment, and taking the median value as the ethane background concentration in the data segment.

4. A methane leak source class identification device based on cruise data, characterized by, The method comprises: a data acquisition module configured to acquire methane concentration data and ethane concentration data output by a gas concentration sensor on a cruise detection vehicle; a data segmentation module configured to determine a methane concentration abnormally enhanced data segment based on the size of the methane concentration, comprising: calculating a methane background concentration X0 based on the methane concentration data; dividing all continuous N or more methane concentration data points greater than a first threshold value into an abnormally enhanced data segment respectively; the first threshold value = (1 + a%) X0, and the size of a is determined according to industry experience; a methane tracing module configured to determine a methane leakage source category based on the relative size and correlation of the methane concentration and the ethane concentration in the data segment, the category comprising a natural gas source, a biogas source and an uncertain gas source; the method for determining the methane leakage source category comprises: S11, calculating a methane-ethane enhancement ratio for data points in each abnormally enhanced data segment: wherein R is the methane-ethane enhancement ratio, Y0 is the ethane background concentration, and X and Y are the methane concentration and the ethane concentration corresponding to the data points in the abnormally enhanced data segment respectively; S12, if R is greater than a second threshold value, turning to S13; otherwise, turning to S14; S13, the correlation between the methane concentration and the ethane concentration is analyzed by using the P value of the Pearson test, if the P value is less than 0.05, it is considered that the correlation is significant, and the methane source is a natural gas source; otherwise, the methane source is an uncertain gas source; S14, whether the ethane concentration at the peak point of the methane concentration is decreased is checked, if yes, the methane source is a biogas source; otherwise, the methane source is an uncertain gas source.

5. The cruise data based methane leak source class identification device of claim 4, wherein, The calculation method of the methane background concentration comprises: S21, a first sliding time window and a second sliding time window with widths of 2n and 2m respectively are set, n < m; S22, calculate the methane concentration median value B in the first sliding time window centered on the t time point tmp,t ; S23, calculate B for each time within a first sliding time window centered at time point t tmp,t and calculate the standard deviation BSD of B for all points within the window tmp,t tmp,t ;​ S24, calculate the BSD within a second sliding time window centered at the t time point tmp,t median MSD of the tmp,t ; S25, the methane background concentration is calculated according to the following formula: where B t is the methane background concentration at time point t, obs t is the methane concentration measurement or observation at time point t, B tmp,t1 , B tmp,t2 are the B tmp,t values at the two endpoints of the time period that satisfy BSD tmp,t ≥ MSD tmp,t , respectively.

6. The cruise data based methane leak source class identification device of claim 5, wherein, The calculation method of the ethane background concentration comprises: the median value of the ethane concentration in the abnormal enhancement data section is calculated, and the median value is taken as the ethane background concentration in the data section.

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