Natural gas leakage quantitative detection method and vehicle-mounted system

Abstract

The invention provides a method and a vehicle-mounted system for quantitative detection of natural gas leakage, and relates to the field of natural gas leakage detection.The vehicle-mounted system comprises a vehicle body, a greenhouse gas analysis module, a meteorological information acquisition module, a positioning module and a leakage analysis module, the greenhouse gas analysis module is used for analyzing gas component information of air in the process that the vehicle body travels along a preset detection path, the weather information acquisition module is used for acquiring real-time weather data in the process that the vehicle body travels along the preset detection path, and the leakage analysis module is used for analyzing the gas component information of the air based on the gas component information of the air at a plurality of continuous time points. Determining the natural gas leakage position and the natural gas leakage mass flow rate based on the real-time meteorological data and the gas component information of the air at a plurality of continuous time points after the existence of the methane emission source is judged and the existence of the natural gas emission source is judged; the method has the advantage of realizing accurate positioning and quantification of natural gas leakage.

Description

Technical Field

[0001] The present invention relates to the field of natural gas leakage detection, and particularly to a method and an on-vehicle system for quantitative detection of natural gas leakage. Background Art

[0002] Methane, which is the main component of natural gas, is a potent greenhouse gas, and its impact on global climate change and the human living environment cannot be underestimated. Natural gas is a flammable mixture mainly composed of methane gas. The leakage of natural gas may cause explosions, resulting in significant property losses and resource waste. Therefore, it is of great significance to detect natural gas leakage and locate the leakage point.

[0003] Currently, existing natural gas leakage detection methods usually use "sniffer" technology and probes for detection, which require close contact with the area to be inspected. The inspectors are exposed to an environment where invisible and potentially explosive risks exist, with low safety. At the same time, in areas where natural gas leakage is detected, it is difficult for existing leakage detection and troubleshooting means to accurately locate natural gas leakage and quantify it, which is a common pain point in the industry.

[0004] Therefore, there is a need to provide a method and an on-vehicle system for quantitative detection of natural gas leakage to achieve accurate location and quantification of natural gas leakage. Summary of the Invention

[0005] The present invention provides an on-vehicle system for quantitative detection of natural gas leakage, including a vehicle body, a greenhouse gas analysis module, a meteorological information acquisition module, a positioning module, and a leakage analysis module provided on the vehicle body. Among them, the vehicle body is used to travel along a preset detection path. The greenhouse gas analysis module is used to analyze the gas component information of the air during the process of the vehicle body traveling along the preset detection path. The greenhouse gas analysis module at least includes a mid-infrared methane analyzer, a mid-infrared ethane analyzer, and a mid-infrared carbon dioxide analyzer. The meteorological information acquisition module is used to acquire real-time meteorological data during the process of the vehicle body traveling along the preset detection path. The meteorological information acquisition module at least includes a wind speed sensor, a wind direction sensor, a temperature and humidity sensor, and a pressure sensor. The positioning module uses the Beidou positioning system. The leakage analysis module is used to judge whether there is a methane emission source based on the gas component information of the air at multiple consecutive time points. After determining that there is a methane emission source, based on the gas component information of the air at multiple consecutive time points, determine the category of the methane emission source. According to the category of the methane emission source, judge whether there is a natural gas emission source. After determining that there is a natural gas emission source, based on the real-time meteorological data and the gas component information of the air at multiple consecutive time points, determine the natural gas leakage location and the natural gas leakage mass flow rate.

[0006] Further, the gas component information of the air includes methane concentration information; the leakage analysis module determines whether there is a methane emission source based on the gas components of the air at multiple consecutive time points, including: determining the background methane concentration at the current time point based on the methane concentration information at multiple consecutive historical time points; calculating the methane concentration difference between the methane concentration information at the current time point and the background methane concentration; and determining that there is a methane emission source when the methane concentration difference is greater than the methane concentration difference threshold.

[0007] Further, the gas component information of the air further includes ethane concentration information; the leakage analysis module determines the category of the methane emission source based on the gas components of the air at multiple consecutive time points, including: determining the category of the methane emission source based on the methane concentration difference between the methane concentration information at the current time point and the background methane concentration and the ethane concentration information at multiple consecutive historical time points.

[0008] Further, the leakage analysis module determines the category of the methane emission source based on the methane concentration difference between the methane concentration information at the current time point and the background methane concentration and the ethane concentration information at multiple consecutive historical time points, including: calculating the methane-ethane concentration change correlation coefficient based on the methane concentration information and the ethane concentration information at multiple consecutive time points; calculating the ethane concentration difference between the ethane concentration information at the current time point and the background ethane concentration; calculating the methane-ethane concentration increment ratio based on the methane concentration difference and the ethane concentration difference; and determining the category of the methane emission source based on the methane-ethane concentration change correlation coefficient and the methane-ethane concentration increment ratio.

[0009] Further, the methane-ethane concentration change correlation coefficient is calculated based on the following formula: where is the methane-ethane concentration change correlation coefficient, is the methane concentration at the i-th time point, is the mean value of the methane concentrations at n consecutive time points, is the ethane concentration at the i-th time point, is the mean value of the ethane concentrations at n consecutive time points.

[0010] Further, the methane-ethane concentration increment ratio is calculated based on the following formula: where η is the methane-ethane concentration increment ratio, is the ethane concentration difference between the ethane concentration information at the current time point and the background ethane concentration, is the methane concentration difference between the methane concentration information at the current time point and the background methane concentration, is the ethane concentration information at the current time point, is the background ethane concentration, is the methane concentration information at the current time point, is the background methane concentration.

[0011] Further, the gas component information of the air further includes carbon dioxide concentration information; the leakage analysis module determines the category of the methane emission source based on the methane-ethane concentration change correlation coefficient and the methane-ethane concentration increment ratio, including: calculating the carbon dioxide-methane concentration change correlation coefficient based on the methane concentration information and the carbon dioxide concentration information at multiple consecutive time points; determining the category of the methane emission source based on the methane-ethane concentration change correlation coefficient, the methane-ethane concentration increment ratio, and the carbon dioxide-methane concentration change correlation coefficient.

[0012] Further, the carbon dioxide-methane concentration change correlation coefficient is calculated based on the following formula: where is the carbon dioxide-methane concentration change correlation coefficient, is the methane concentration at the i-th time point, is the average value of the methane concentrations at n consecutive time points, is the carbon dioxide concentration at the i-th time point, is the average value of the carbon dioxide concentrations at n consecutive time points.

[0013] Further, the leakage analysis module determines the category of the methane emission source based on the methane-ethane concentration change correlation coefficient, the methane-ethane concentration increment ratio, and the carbon dioxide-methane concentration change correlation coefficient, including: when the methane-ethane concentration change correlation coefficient is greater than the methane-ethane concentration change correlation coefficient threshold, the difference between the methane-ethane concentration increment ratio and the preset methane-ethane concentration increment ratio is less than the difference threshold, and when the carbon dioxide-methane concentration change correlation coefficient is greater than the carbon dioxide-methane concentration change correlation coefficient threshold, it is determined that the category of the methane emission source is a natural gas emission source.

[0014] The present invention provides a method for quantitative detection of natural gas leakage, including: controlling the vehicle body to travel along a preset detection path; analyzing the gas component information of the air during the process of the vehicle body traveling along the preset detection path; obtaining real-time meteorological data during the process of the vehicle body traveling along the preset detection path; determining whether there is a methane emission source based on the gas component information of the air at multiple consecutive time points; after determining that there is a methane emission source, determining the category of the methane emission source based on the gas component information of the air at multiple consecutive time points; judging whether there is a natural gas emission source according to the category of the methane emission source; after determining that there is a natural gas emission source, determining the natural gas leakage position and the natural gas leakage mass flow rate based on the real-time meteorological data and the gas component information of the air at multiple consecutive time points.

[0015] Compared with the prior art, the method and vehicle-mounted system for quantitative detection of natural gas leakage provided by the present invention have at least the following beneficial effects:

[0016] It can analyze the air composition along the way in real time, and combine with real-time meteorological data to quickly identify and locate the natural gas leakage source. This greatly improves the efficiency and accuracy of leakage detection, and helps to take timely measures to prevent further energy waste and environmental pollution. Through the collection and analysis of data at multiple consecutive time points, the system can accurately calculate the mass flow rate of natural gas leakage, providing specific data support for subsequent repair work. This helps to evaluate the severity of the leakage, formulate a reasonable repair plan, and estimate the repair cost. The leakage analysis module can distinguish different types of methane emission sources, so as to more accurately judge whether it is natural gas leakage. This intelligent classification function reduces the possibility of false alarms, improves the overall reliability, greatly improves the detection efficiency and accuracy, reduces the manpower and material resources required for manual inspection, and can accurately quantify the methane leakage amount at the leakage point based on the detection data, further exploring the use value of the detection system. It helps to timely identify natural gas leakage points with high potential safety hazards, and then repair them in time to eliminate potential risks and ensure the safe operation of the urban natural gas transmission and distribution system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] This specification will be further described in the form of exemplary embodiments, and these exemplary embodiments will be described in detail through the drawings. These embodiments are not restrictive. In these embodiments, the same numbers represent the same structures, where:

[0018] Figure 1 is a schematic diagram of the modules of a vehicle-mounted system for quantitative detection of natural gas leakage shown in some embodiments of this specification;

[0019] Figure 2 is a schematic diagram of the process of quantitative detection of natural gas leakage shown in some embodiments of this specification;

[0020] Figure 3 is a schematic diagram of the process of a method for quantitative detection of natural gas leakage shown in some embodiments of this specification. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of this specification, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some examples or embodiments of this specification. For those of ordinary skill in the art, without creative efforts, this specification can also be applied to other similar scenarios based on these drawings. Unless it is obvious from the language context or otherwise stated, the same reference numerals in the drawings represent the same structure or operation.

[0022] Figure 1 is a schematic diagram of modules of a vehicle-mounted system for quantitative detection of natural gas leakage shown in some embodiments of this specification. As Figure 1 shown, the vehicle-mounted system for quantitative detection of natural gas leakage may include a vehicle body ( Figure 1 not shown in the figure), a greenhouse gas analysis module, a meteorological information acquisition module, a positioning module, and a leakage analysis module disposed on the vehicle body.

[0023] Among them, the vehicle body is used to travel along a preset detection path. The greenhouse gas analysis module is used to analyze the gas component information of the air during the vehicle body traveling along the preset detection path. The greenhouse gas analysis module at least includes a mid-infrared methane analyzer, a mid-infrared ethane analyzer, and a mid-infrared carbon dioxide analyzer. The meteorological information acquisition module is used to acquire real-time meteorological data during the vehicle body traveling along the preset detection path. The meteorological information acquisition module at least includes a wind speed sensor, a wind direction sensor, a temperature and humidity sensor, and a pressure sensor. The leakage analysis module is used to judge whether there is a methane emission source based on the gas component information of the air at multiple consecutive time points. After determining that there is a methane emission source, based on the gas component information of the air at multiple consecutive time points, determine the category of the methane emission source. According to the category of the methane emission source, judge whether there is a natural gas emission source. After determining that there is a natural gas emission source, based on the real-time meteorological data and the gas component information of the air at multiple consecutive time points, determine the natural gas leakage location and the natural gas leakage mass flow rate.

[0024] The vehicle-mounted system for quantitative detection of natural gas leakage may further include a network module, which provides a communication function and transmits the detection data to the mobile terminal in real time.

[0025] Preferably, the gas component information of the air includes methane concentration information.

[0026] The network module uses a 4G network.

[0027] Figure 2 is a schematic diagram of the process of quantitative detection of natural gas leakage shown in some embodiments of this specification. As Figure 2 shown, preferably, the leakage analysis module judges whether there is a methane emission source based on the gas components of the air at multiple consecutive time points, including:

[0028] Determine the background methane concentration at the current time point based on the methane concentration information at multiple consecutive historical time points;

[0029] Calculate the methane concentration difference between the methane concentration information at the current time point and the background methane concentration;

[0030] When the methane concentration difference is greater than the methane concentration difference threshold, it is determined that there is a methane emission source.

[0031] Specifically, the background methane concentration at the current time point can be calculated based on the following formula:

[0032]

[0033] Wherein, is the background methane concentration at the current time point, is the background methane concentration at a historical time point before the current time point, and m is the total number of multiple consecutive historical time points selected.

[0034] For example, the background methane concentration at the current time point can be determined based on the methane concentration information of 600 consecutive time points:

[0035]

[0036] When the following conditions are met, it is determined that there is a methane emission source:

[0037]

[0038] Wherein, is the methane concentration information at the current time point.

[0039] Preferably, the gas component information of the air further includes ethane concentration information.

[0040] As shown in Figure 2 Preferably, the leakage analysis module determines the category of the methane emission source based on the gas components of the air at multiple consecutive time points, including:

[0041] Determine the category of the methane emission source based on the methane concentration difference between the methane concentration information at the current time point and the background methane concentration and the ethane concentration information at multiple consecutive historical time points.

[0042] Preferably, the leakage analysis module determines the category of the methane emission source based on the methane concentration difference between the methane concentration information at the current time point and the background methane concentration and the ethane concentration information at multiple consecutive historical time points, including:

[0043] Calculate the correlation coefficient related to the change in methane and ethane concentrations based on the methane concentration information and ethane concentration information at multiple consecutive time points;

[0044] Calculate the ethane concentration difference between the ethane concentration information at the current time point and the background ethane concentration;

[0045] Calculate the methane-ethane concentration increment ratio based on the methane concentration difference and the ethane concentration difference;

[0046] Determine the category of the methane emission source based on the correlation coefficient related to the change in methane and ethane concentrations and the methane-ethane concentration increment ratio.

[0047] Specifically, the correlation coefficient related to the concentration change of methane and ethane can be calculated based on the following formula:

[0048]

[0049] Wherein, is the correlation coefficient related to the concentration change of methane and ethane, is the methane concentration at the i-th time point, is the average value of the methane concentrations at n consecutive time points, is the ethane concentration at the i-th time point, is the average value of the ethane concentrations at n consecutive time points.

[0050] For example, the methane concentration information and ethane concentration information at thirty time points including the current time point can be selected to calculate the correlation coefficient related to the concentration change of methane and ethane:

[0051]

[0052] The method for calculating the background ethane concentration is similar to that for calculating the background methane concentration, which will not be elaborated here.

[0053] The ratio of the concentration increment of methane and ethane can be calculated based on the following formula:

[0054]

[0055] Wherein, η is the ratio of the concentration increment of methane and ethane, is the difference in ethane concentration between the ethane concentration information at the current time point and the background ethane concentration, is the difference in methane concentration between the methane concentration information at the current time point and the background methane concentration, is the ethane concentration information at the current time point, is the background ethane concentration, is the methane concentration information at the current time point, is the background methane concentration.

[0056] Preferably, the gas component information of the air further includes carbon dioxide concentration information;

[0057] Preferably, the leakage analysis module determines the category of the methane emission source based on the correlation coefficient related to the concentration change of methane and ethane and the ratio of the concentration increment of methane and ethane, including:

[0058] Calculate the correlation coefficient of the carbon dioxide-methane concentration change based on the methane concentration information and carbon dioxide concentration information at multiple consecutive time points;

[0059] Determine the category of the methane emission source based on the correlation coefficient related to the concentration change of methane and ethane, the ratio of the concentration increment of methane and ethane, and the correlation coefficient of the carbon dioxide-methane concentration change.

[0060] Preferably, the correlation coefficient related to the change in carbon dioxide and methane concentrations is calculated based on the following formula:

[0061]

[0062] where: is the correlation coefficient related to the change in carbon dioxide and methane concentrations, is the methane concentration at the i-th time point, is the average value of the methane concentrations at n consecutive time points, is the carbon dioxide concentration at the i-th time point, is the average value of the carbon dioxide concentrations at n consecutive time points.

[0063] Preferably, the leakage analysis module determines the category of the methane emission source based on the correlation coefficient of the change in methyl-ethane concentrations, the ratio of the increment of methyl-ethane concentrations, and the correlation coefficient of the change in carbon dioxide and methane concentrations, including:

[0064] When the correlation coefficient of the change in methyl-ethane concentrations is greater than the threshold value of the correlation coefficient of the change in methyl-ethane concentrations, the difference between the ratio of the increment of methyl-ethane concentrations and the preset ratio of the increment of methyl-ethane concentrations is less than the threshold value of the difference, and when the correlation coefficient of the change in carbon dioxide and methane concentrations is greater than the threshold value of the correlation coefficient of the change in carbon dioxide and methane concentrations, it is determined that the category of the methane emission source is a natural gas emission source.

[0065] where the preset ratio of the increment of methyl-ethane concentrations can be calculated based on the volume fractions of methane and ethane in the natural gas components supplied locally. For example, the preset ratio of the increment of methyl-ethane concentrations can be calculated based on the following formula:

[0066]

[0067] where η0 is the preset ratio of the increment of methyl-ethane concentrations, is the volume fraction of ethane in the natural gas components supplied locally, is the volume fraction of methane in the natural gas components supplied locally.

[0068] Since natural gas is a mixed gas containing methane and ethane, when a natural gas emission source is detected, the concentrations of methane and ethane will rise simultaneously. The type of emission source can be identified through the degree of correlation between the two. When the correlation coefficient is greater than or equal to 0.9, the leakage source can be considered as a natural gas leakage. The natural gas emission sources in the city also include unburned methane and ethane in the exhaust gas of vehicles fueled by compressed natural gas (CNG). Therefore, it is necessary to exclude its interference to accurately identify the natural gas leakage in the gas transmission and distribution system. Another major characteristic of vehicle exhaust gas is its relatively high carbon dioxide concentration. For a methane emission source that has been determined to be a natural gas leakage, if the detection data simultaneously meet the conditions that the carbon dioxide concentration is greater than 500 ppm and the correlation coefficient between carbon dioxide and methane is greater than or equal to 0.8, it should be identified as the exhaust gas of a CNG (Compressed Natural Gas) vehicle.

[0069] For the natural gas emission sources excluding the type of CNG vehicle exhaust gas, it should be identified as a natural gas leakage in the urban gas transmission and distribution pipeline network.

[0070] Based on the real-time meteorological data and air gas composition information at multiple consecutive time points by manual, combined with the Gaussian source diffusion model, the natural gas leakage location can be determined. The calculation method of the Gaussian source model is as follows:

[0071]

[0072] where C(x, y, z) is the pollutant concentration at the spatial point (x, y, z), σ y is the standard deviation in the horizontal direction, that is, the diffusion parameter in the y direction, σ z is the standard deviation in the vertical direction, that is, the diffusion parameter in the z direction. is the average wind speed, q is the pollutant emission source intensity, x is the distance from the spatial point to the source on the wind direction axis, y is the distance from the spatial point to the source in the direction perpendicular to the wind direction axis, and z is the height of the spatial point.

[0073] The natural gas leakage location can also be determined through a machine learning model based on the real-time meteorological data and air gas composition information at multiple consecutive time points. Among them, the machine learning model can be a long short-term memory network (LSTM, Long Short-Term Memory) model.

[0074] The methane emission rate of the located leakage point is calculated through the following formula:

[0075]

[0076] where, is the methane emission mass flow rate at the leakage point, g / h, L is the minimum distance from the natural gas leakage point to the vehicle body, m, is the maximum concentration increment of methane, ppb.

[0077] The mass flow rate of natural gas leakage at the leakage point can be obtained from the proportion of methane component in the natural gas supplied from this location:

[0078]

[0079] Among them, q NG is the mass flow rate of natural gas leakage at the leakage point, in g / h.

[0080] Adding up the methane emission rates of all leakage points in the detection area can obtain the methane emission intensity of the gas transmission and distribution pipeline network in this area:

[0081]

[0082] Among them, is the methane emission intensity of the detection area, in g / h.

[0083] Adding up the mass flow rates of natural gas leakage at all leakage points in the detection area can obtain the calculation method of the natural gas leakage flow rate in the entire detection area:

[0084] Q NG = ∑q NG

[0085] Among them, Q NG is the natural gas leakage flow rate of the detection area, in g / h.

[0086] Figure 3 is a schematic flow chart of the method for quantitative detection of natural gas leakage shown in some embodiments of this specification. As Figure 3 shown, the method for quantitative detection of natural gas leakage may include the following steps.

[0087] Step 310, controlling the vehicle body to travel along a preset detection path;

[0088] Step 320, analyzing the gas component information of the air during the process of the vehicle body traveling along the preset detection path;

[0089] Step 330, obtaining real-time meteorological data during the process of the vehicle body traveling along the preset detection path;

[0090] Step 340, based on the gas component information of the air at multiple consecutive time points, determining whether there is a methane emission source;

[0091] Step 350, after determining that there is a methane emission source, based on the gas component information of the air at multiple consecutive time points, determining the category of the methane emission source;

[0092] Step 360, judging whether there is a natural gas emission source according to the category of the methane emission source;

[0093] Step 370, after determining that there is a natural gas emission source, based on the real-time meteorological data at multiple consecutive time points and the gas composition information of the air, determine the natural gas leakage location and the natural gas leakage mass flow rate.

[0094] The vehicle-mounted system for quantitative detection of natural gas leakage can be used to execute the method for quantitative detection of natural gas leakage. For more descriptions of the method for quantitative detection of natural gas leakage, reference can be made to the relevant descriptions of the vehicle-mounted system for quantitative detection of natural gas leakage, which will not be elaborated here.

[0095] Finally, it should be understood that the embodiments described in this specification are only used to illustrate the principles of the embodiments of this specification. Other deformations may also fall within the scope of this specification. Therefore, by way of example rather than limitation, alternative configurations of the embodiments of this specification can be regarded as consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly introduced and described in this specification.

Claims

1. An on-vehicle system for quantitative detection of natural gas leakage, characterized in that, It includes a vehicle body, a greenhouse gas analysis module, a meteorological information acquisition module, a positioning module, and a leakage analysis module provided on the vehicle body. Among them, the vehicle body is used to travel along a preset detection path. The greenhouse gas analysis module is used to analyze the gas component information of the air during the process of the vehicle body traveling along the preset detection path. The greenhouse gas analysis module at least includes a mid-infrared methane analyzer, a mid-infrared ethane analyzer, and a mid-infrared carbon dioxide analyzer. The meteorological information acquisition module is used to acquire real-time meteorological data during the process of the vehicle body traveling along the preset detection path. The meteorological information acquisition module at least includes a wind speed sensor, a wind direction sensor, a temperature and humidity sensor, and a pressure sensor. The positioning module uses the Beidou positioning system. The leakage analysis module is used to judge whether there is a methane emission source based on the gas component information of the air at multiple consecutive time points. After determining that there is a methane emission source, based on the gas component information of the air at multiple consecutive time points, determine the category of the methane emission source. According to the category of the methane emission source, judge whether there is a natural gas emission source. After determining that there is a natural gas emission source, based on the real-time meteorological data and the gas component information of the air at multiple consecutive time points, determine the natural gas leakage position and the natural gas leakage mass flow rate.

2. The vehicle-mounted system for quantitative detection of natural gas leakage according to claim 1, wherein The gas component information of the air includes methane concentration information; The leakage analysis module judges whether there is a methane emission source based on the gas components of the air at multiple consecutive time points, including: Determine the background methane concentration at the current time point based on the methane concentration information at multiple consecutive historical time points; Calculate the methane concentration difference between the methane concentration information at the current time point and the background methane concentration; When the methane concentration difference is greater than the methane concentration difference threshold, it is determined that there is a methane emission source.

3. The vehicle-mounted system for quantitative detection of natural gas leakage according to claim 2, wherein The gas component information of the air also includes ethane concentration information; The leakage analysis module determines the category of the methane emission source based on the gas components of the air at multiple consecutive time points, including: Determine the category of the methane emission source based on the methane concentration difference between the methane concentration information at the current time point and the background methane concentration and the ethane concentration information at multiple consecutive historical time points.

4. The vehicle-mounted system for quantitative detection of natural gas leakage according to claim 3, characterized in that, The leakage analysis module determines the category of the methane emission source based on the methane concentration difference between the methane concentration information at the current time point and the background methane concentration and the ethane concentration information at multiple consecutive historical time points, including: Calculate the methane-ethane concentration change correlation coefficient based on the methane concentration information and ethane concentration information at multiple consecutive time points; Calculate the ethane concentration difference between the ethane concentration information at the current time point and the background ethane concentration; Calculate the methane-ethane concentration increment ratio based on the methane concentration difference and the ethane concentration difference; Determine the category of the methane emission source based on the methane-ethane concentration change correlation coefficient and the methane-ethane concentration increment ratio.

5. The vehicle-mounted system for quantitative detection of natural gas leakage according to claim 4, characterized in that, Calculate the methane-ethane concentration change correlation coefficient based on the following formula: Among them, is the correlation coefficient related to the change in the concentration of methyl ethane, is the methane concentration at the i-th time point, is the mean value of the methane concentration at n consecutive time points, is the ethane concentration at the i-th time point, is the mean value of the ethane concentration at n consecutive time points.

6. The vehicle-mounted system for quantifying and detecting natural gas leakage according to claim 4, wherein, Calculate the methane-ethane concentration increment ratio based on the following formula: Among them, η is the ratio of the concentration increment of ethane to methane, is the ethane concentration difference between the ethane concentration information at the current time point and the background ethane concentration, is the methane concentration difference between the methane concentration information at the current time point and the background methane concentration, is the ethane concentration information at the current time point, is the background ethane concentration, is the methane concentration information at the current time point, is the background methane concentration.

7. The vehicle-mounted system for natural gas leakage quantification detection according to any one of claims 4-6, characterized in that, The gas component information of the air also includes carbon dioxide concentration information; The leakage analysis module determines the category of the methane emission source based on the correlation coefficient of the concentration change of methane and ethane and the ratio of the concentration increment of methane and ethane, including: Calculating the correlation coefficient of the concentration change of carbon dioxide and methane based on the methane concentration information and carbon dioxide concentration information at multiple consecutive time points; Determining the category of the methane emission source based on the correlation coefficient of the concentration change of methane and ethane, the ratio of the concentration increment of methane and ethane, and the correlation coefficient of the concentration change of carbon dioxide and methane.

8. The vehicle-mounted system for quantitative detection of natural gas leakage according to claim 7, wherein Calculating the correlation coefficient of the concentration change of carbon dioxide and methane based on the following formula: Among them, is the correlation coefficient related to the change in carbon dioxide and methane concentrations, is the methane concentration at the i-th time point, is the mean value of methane concentrations at n consecutive time points, is the carbon dioxide concentration at the i-th time point, is the mean value of carbon dioxide concentrations at n consecutive time points.

9. The vehicle-mounted system for quantitative detection of natural gas leakage according to claim 7, characterized in that, The leakage analysis module determines the category of the methane emission source based on the correlation coefficient of the concentration change of methane and ethane, the ratio of the concentration increment of methane and ethane, and the correlation coefficient of the concentration change of carbon dioxide and methane, including: When the correlation coefficient of the concentration change of methane and ethane is greater than the threshold of the correlation coefficient of the concentration change of methane and ethane, the difference between the ratio of the concentration increment of methane and ethane and the preset ratio of the concentration increment of methane and ethane is less than the difference threshold, and when the correlation coefficient of the concentration change of carbon dioxide and methane is greater than the threshold of the correlation coefficient of the concentration change of carbon dioxide and methane, it is determined that the category of the methane emission source is a natural gas emission source.

10. A method for quantitatively detecting natural gas leakage, characterized in that, Including: Controlling the vehicle body to travel along a preset detection path; Analyzing the gas component information of the air during the process of the vehicle body traveling along the preset detection path; Obtaining real-time meteorological data during the process of the vehicle body traveling along the preset detection path; Judging whether there is a methane emission source based on the gas component information of the air at multiple consecutive time points; After determining that there is a methane emission source, determining the category of the methane emission source based on the gas component information of the air at multiple consecutive time points; Judging whether there is a natural gas emission source according to the category of the methane emission source; After determining that there is a natural gas emission source, determining the natural gas leakage location and the natural gas leakage mass flow rate based on the real-time meteorological data and the gas component information of the air at multiple consecutive time points.

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