Gas leakage detection method and device based on intelligent gas meter and concentration sensor

Abstract

The application provides a gas leakage detection method and device based on a smart gas meter and a concentration sensor. The method comprises the following steps: acquiring a gas flow from the smart gas meter in real time; acquiring a gas concentration from a concentration measuring unit in real time; and determining whether there is gas leakage based on the fusion of the gas flow and the gas concentration. The application performs gas leakage detection based on the fusion of the gas flow acquired from the smart gas meter in real time and the gas concentration acquired from the concentration measuring unit in real time. Compared with the prior art which detects leakage by measuring the gas concentration in the room of a user only, the application can effectively detect more obvious leakage, improves the accuracy of gas leakage detection and the concentration range of leakage detection, and especially improves the detection capability for weak gas leakage.

Description

Technical Field

[0001] This invention belongs to the field of gas leak detection technology, specifically relating to a gas leak detection method and device based on a smart gas meter and a concentration sensor. Background Technology

[0002] With the widespread use of natural gas, gas leaks due to damage or poor sealing in residential gas facilities are frequent. However, the industry's measures for detecting indoor leaks are not yet ideal. On the one hand, the conventional method for detecting gas leaks in residential homes mainly involves installing gas alarms to detect excessive concentrations. However, commercially available gas alarms have limited sensitivity and cannot effectively identify minor leaks. They are also prone to false alarms due to interference from other components (such as volatile components from seasonings and oil fumes). On the other hand, after a leak occurs, the location, shape, and size of the leak are difficult to measure effectively, making it difficult to reasonably estimate the amount of gas lost, which in turn leads to errors in the gas company's sales and purchase accounting. Therefore, a hybrid method is needed that can achieve both a wider concentration monitoring range for gas leaks and a reasonable estimation of the amount of gas leaked. Currently, the rapidly deployed smart gas meters in the industry can not only directly monitor changes in gas flow but also have data transmission and algorithm analysis capabilities, making them a good carrier for integrated indoor safety monitoring solutions.

[0003] Currently, existing indoor gas leak detection technologies generally employ a single detection method, making it difficult to accurately identify and warn of even minor leaks. Furthermore, there is a lack of effective methods for estimating the amount of gas leaked after an indoor leak occurs. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, this invention provides a gas leak detection method and apparatus based on a smart gas meter and a concentration sensor.

[0005] To achieve the above objectives, the present invention adopts the following technical solution.

[0006] In a first aspect, the present invention provides a gas leak detection method based on a smart gas meter and a concentration sensor, comprising the following steps:

[0007] Get real-time gas flow from smart gas meters;

[0008] Real-time gas concentration is obtained from the concentration measurement unit;

[0009] The presence of a gas leak is determined based on the fusion of the gas flow rate and gas concentration.

[0010] Further, the method further includes: uploading the detection result of whether there is gas leakage and / or the gas consumption data and gas concentration data obtained in real time to the host computer at the main station.

[0011] Furthermore, the method further includes: when the detection result indicates that there is gas leakage, sending an alarm reminder signal by the control processing unit and / or the host computer; when the leakage is serious, sending an instruction to the intelligent gas meter to cut off the gas supply solenoid valve.

[0012] Further, the method further includes: when it is detected that there is gas leakage, determining the approximate location of the gas leakage point according to the gas flow rate and gas concentration: on the inlet side or the outlet side of the intelligent gas meter.

[0013] Furthermore, the fusion based on the gas flow rate and gas concentration to determine whether there is gas leakage specifically includes:

[0014] Let q represent the gas flow rate obtained in real time from the intelligent gas meter, and let c represent the gas concentration in the indoor area of the intelligent gas meter user obtained in real time from the concentration measurement unit; determine whether there is gas leakage according to the magnitudes of q and c by the following method:

[0015] If c = 0 and q = 0, there is no gas leakage;

[0016] If c = 0 and 0 < q min ≤ q ≤ q max , and the duration does not exceed the first threshold, there is no gas leakage; where q min , q max are the minimum value and the maximum value of the gas flow rate during normal gas use by the intelligent gas meter user respectively;

[0017] If 0 < c ≤ LEL and q = 0, there is a leakage risk. Further predict the time T when the gas concentration reaches LEL. If T is less than the second threshold, there is gas leakage, and the leakage point is on the inlet side of the intelligent gas meter; where LEL is the minimum gas concentration that causes an explosion;

[0018] If 0 < c ≤ LEL and 0 < q ≤ q min , there is a leakage risk. Further predict the time T when the gas concentration reaches LEL. If T is less than the second threshold, there is gas leakage, and the leakage point is on the outlet side of the intelligent gas meter;

[0019] If 0 < c ≤ LEL and q min ≤ q ≤ q max , there is gas leakage, and the leakage point is on the outlet side of the intelligent gas meter;

[0020] If c > LEL and q = 0, there is gas leakage, and the leakage point is on the inlet side of the intelligent gas meter;

[0021] If c > LEL, q min ≤q≤q max If so, there is a gas leak, and the leak point is located on the gas outlet side of the smart gas meter;

[0022] If c > LEL, then q > q max If so, there is a gas leak, and the leak point is located on the gas outlet side of the smart gas meter.

[0023] Furthermore, gas concentration prediction methods include:

[0024] Based on the conservation of gas mass in the room:

[0025]

[0026] In the formula, t is time, V is room volume, c is the gas concentration in the room, and q is the concentration of gas in the room. x Here, k represents the gas leakage rate, and k represents the number of air changes per hour in the room.

[0027] Solving the differential equation with c as the variable in equation (1) yields the prediction model for gas concentration:

[0028]

[0029] In the formula, c0 is the initial gas concentration, q x The gas concentration was obtained by fitting the data using the least squares method based on the gas concentration at multiple historical moments.

[0030] Secondly, the present invention provides a gas leak detection device based on a smart gas meter and a concentration sensor, comprising:

[0031] The flow acquisition module is used to acquire the gas flow from the smart gas meter in real time;

[0032] The concentration acquisition module is used to acquire the gas concentration from the concentration measurement unit in real time.

[0033] The leakage detection module is used to determine whether a gas leak exists based on the fusion of the gas flow rate and gas concentration.

[0034] Furthermore, the device also includes a data uploading module, used to upload the detection results of whether a gas leak exists and / or the real-time gas consumption data and gas concentration data to the host computer of the main station.

[0035] Furthermore, the device also includes an alarm module, which is used to send an alarm reminder signal by the control processing unit and / or the host computer when the detection result indicates that there is a gas leak; and to send a command to the smart gas meter to cut off the gas supply solenoid valve when the leak is serious.

[0036] Further, the device further includes a leakage location module, configured to determine a rough location of the gas leakage point when detecting gas leakage, which is located on the intake side or the outlet side of the intelligent gas meter, according to the gas flow rate and gas concentration.

[0037] Furthermore, the fusion based on the gas flow rate and gas concentration to determine whether there is gas leakage specifically includes:

[0038] Let q represent the gas flow rate obtained in real time from the intelligent gas meter, and let c represent the gas concentration in the indoor area of the intelligent gas meter user obtained in real time from the concentration measurement unit. Determine whether there is gas leakage according to the magnitudes of q and c by the following method:

[0039] If c = 0 and q = 0, there is no gas leakage;

[0040] If c = 0 and 0 < q min ≤ q ≤ q max , and the duration does not exceed the first threshold, there is no gas leakage; where q min , q max are respectively the minimum and maximum values of the gas flow rate when the intelligent gas meter user is using gas normally;

[0041] If 0 < c ≤ LEL and q = 0, there is a leakage risk. Further predict the time T when the gas concentration reaches LEL. If T is less than the second threshold, there is gas leakage, and the leakage point is located on the intake side of the intelligent gas meter; where LEL is the minimum value of the gas concentration causing an explosion;

[0042] If 0 < c ≤ LEL and 0 < q ≤ q min , there is a leakage risk. Further predict the time T when the gas concentration reaches LEL. If T is less than the second threshold, there is gas leakage, and the leakage point is located on the outlet side of the intelligent gas meter;

[0043] If 0 < c ≤ LEL and q min ≤ q ≤ q max , there is gas leakage, and the leakage point is located on the outlet side of the intelligent gas meter;

[0044] If c > LEL and q = 0, there is gas leakage, and the leakage point is located on the intake side of the intelligent gas meter;

[0045] If c > LEL and q min ≤ q ≤ q max , there is gas leakage, and the leakage point is located on the outlet side of the intelligent gas meter;

[0046] If c > LEL and q > q max , there is gas leakage, and the leakage point is located on the outlet side of the intelligent gas meter.

[0047] Furthermore, gas concentration prediction methods include:

[0048] Based on the conservation of gas mass in the room:

[0049]

[0050] In the formula, t is time, V is room volume, c is the gas concentration in the room, and q is the concentration of gas in the room. x Here, k represents the gas leakage rate, and k represents the number of air changes per hour in the room.

[0051] Solving the differential equation with c as the variable in equation (1) yields the prediction model for gas concentration:

[0052]

[0053] In the formula, c0 is the initial gas concentration, q x The gas concentration was obtained by fitting the data using the least squares method based on the gas concentration at multiple historical moments.

[0054] Compared with the prior art, the present invention has the following beneficial effects.

[0055] This invention achieves automatic gas leak detection by acquiring real-time gas flow from a smart gas meter and real-time gas concentration from a concentration measurement unit, and then determining the presence of a gas leak based on the fusion of these two measurements. Compared to existing technologies that rely solely on measuring indoor gas concentration, which only effectively detects significant leaks, this invention improves the accuracy and concentration range of gas leak detection, particularly enhancing the detection capability for minute gas leaks. Furthermore, the fusion detection via the gas meter provides supplementary leak assessment, mitigating the false alarms and missed alarms inherent in single-alarm systems. Attached Figure Description

[0056] Figure 1 This is a flowchart illustrating a gas leak detection method based on a smart gas meter and a concentration sensor, according to an embodiment of the present invention.

[0057] Figure 2 This is a schematic diagram of the hardware structure of the detection system.

[0058] Figure 3 This is a schematic diagram of the indoor gas concentration prediction curve.

[0059] Figure 4 This is a block diagram of a gas leak detection device based on a smart gas meter and a concentration sensor, according to an embodiment of the present invention. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this invention clearer and more understandable, the invention will be further described below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0061] Figure 1 This is a flowchart of a gas leak detection method based on a smart gas meter and a concentration sensor, according to an embodiment of the present invention, including the following steps:

[0062] Step 101: Obtain gas flow rate in real time from the smart gas meter;

[0063] Step 102: Obtain the gas concentration in real time from the concentration measurement unit;

[0064] Step 103: Determine whether there is a gas leak based on the fusion of the gas flow rate and gas concentration.

[0065] This embodiment provides a gas leak detection method based on a smart gas meter and a concentration sensor. The hardware structure for implementing the method described in this embodiment is as follows: Figure 2 As shown, the system includes a smart gas meter (comprising a base meter, communication module, and control module), a concentration measurement unit, and a control processing unit installed in the user's home (typically the kitchen), as well as a host computer for the main station. The base meter for the smart gas meter can be either an ultrasonic gas meter or a diaphragm gas meter. If an ultrasonic gas meter is used as the base meter, it should have real-time gas flow reading, display, and transmission capabilities; if a diaphragm gas meter is used, it should have pulse reading capabilities and calculate the corresponding gas flow based on pulses per unit time (the calculation interval is recommended to be no more than 1 minute). The smart gas meter has a remote communication module supporting NB, 4G, LoRa, and other communication methods; it is best to have an auxiliary backup communication channel, including but not limited to Bluetooth and infrared channels, for after-sales maintenance, parameter modification and setting, or data acquisition and transmission when the main communication channel (remote communication module) malfunctions. The smart gas meter can communicate with the control processing unit and interact with the host computer for the main station. The concentration measurement unit mainly consists of a gas concentration sensor and a communication module, which transmits the gas concentration data to the control processing unit. The control processing unit is used to determine whether a gas leak exists by performing necessary data processing based on gas flow and gas concentration. If a gas leak is found, an alarm is triggered to alert the user of the leak risk. The control processing unit generally also has a display function, which can display prompts to the user on the screen.

[0066] This embodiment is implemented by executing steps 101-103 in the control processing unit. Step 101 is mainly used to obtain the gas flow rate from the smart gas meter in real time, step 102 is mainly used to obtain the gas concentration from the concentration measurement unit in real time, and step 103 is mainly used to determine whether a gas leak exists based on the fusion of the gas flow rate and gas concentration. Existing technologies generally only measure the gas concentration in the user's room and compare it with a set threshold. If the concentration exceeds the set threshold, it is considered that a gas leak exists. This measurement method is feasible when the gas leak is relatively obvious; however, when the gas leak is very weak, it is difficult to detect effectively because to detect a very weak leak, the threshold needs to be set very low, but when the threshold is very low, a high probability of false alarms will occur, meaning that many noise or interference signals will be falsely reported as a gas leak. Therefore, this embodiment combines the real-time gas flow rate and the real-time gas concentration obtained from the smart gas meter to determine the gas leak, thereby improving the detection accuracy and detection concentration range of gas leaks.

[0067] As an optional embodiment, the method further includes: uploading the detection results of whether a gas leak exists and / or the real-time gas consumption data and gas concentration data to the host computer of the main station.

[0068] In this embodiment, the control processing unit also uploads the gas leak detection results to the host computer at the main station, so that the main station can monitor the user's safe gas usage in real time and take appropriate measures when necessary. The control processing unit in this embodiment can also upload the real-time gas consumption data and gas concentration data to the host computer at the main station, where the host computer will perform gas leak determination based on the necessary data processing. In other words, gas leak determination can be implemented by either the control processing unit or the host computer at the main station.

[0069] As an optional embodiment, the method further includes: when the detection result indicates the presence of gas leakage, the control processing unit and / or the host computer send an alarm reminder signal; when the leakage is severe, a command is sent to the smart gas meter to cut off the gas supply solenoid valve.

[0070] In this embodiment, when a gas leak is detected, an alarm signal is issued to remind the user to take necessary precautions. If the leak is severe, a command is sent to the smart gas meter, which then directly shuts off the gas supply solenoid valve to prevent danger. Upon receiving the alarm signal, the host computer reminds the on-duty personnel to take appropriate measures based on the severity of the gas leak, such as arranging for workers to conduct on-site inspections. The alarm signal can be an audible and visual alarm, a voice alarm, or a text prompt displayed on the screen.

[0071] As an optional embodiment, the method further includes: when detecting a gas leak, determining a rough location of the gas leak point according to the gas flow rate and gas concentration: on the inlet side or the outlet side of the intelligent gas meter.

[0072] In this embodiment, in addition to detecting whether there is a gas leak, it is also necessary to determine the rough location of the gas leak point when detecting a gas leak. The rough location of the gas leak point is relative to the intelligent gas meter, whether it is on the inlet side of the intelligent gas meter (also called in front of the gas meter) or the outlet side of the intelligent gas meter (also called behind the gas meter). The rough location can be determined according to the size of the gas flow rate relative to the normal gas flow rate value: if the leak point is behind the intelligent gas meter, the gas flow rate will be greater than the normal value; if the leak point is in front of the intelligent gas meter, the gas flow rate will be less than the normal value. With the rough location of the leak point, it is convenient for users or maintenance personnel to conduct inspections.

[0073] As an optional embodiment, the fusion-based determination of whether there is a gas leak based on the gas flow rate and gas concentration specifically includes:

[0074] Let q represent the gas flow rate obtained in real time from the intelligent gas meter, and let c represent the gas concentration in the user's room of the intelligent gas meter obtained in real time from the concentration measurement unit; determine whether there is a gas leak according to the sizes of q and c by the following method:

[0075] If c = 0 and q = 0, there is no gas leak;

[0076] If c = 0 and 0 < q min ≤ q ≤ q max , and the duration does not exceed the first threshold, then there is no gas leak; where q min , q max are respectively the minimum value and the maximum value of the gas flow rate when the user of the intelligent gas meter uses gas normally;

[0077] If 0 < c ≤ LEL and q = 0, there is a leakage risk. Further predict the time T when the gas concentration reaches LEL. If T is less than the second threshold, there is a gas leak, and the leak point is located on the inlet side of the intelligent gas meter; where LEL is the minimum value of the gas concentration causing an explosion;

[0078] If 0 < c ≤ LEL and 0 < q ≤ q min , there is a leakage risk. Further predict the time T when the gas concentration reaches LEL. If T is less than the second threshold, there is a gas leak, and the leak point is located on the outlet side of the intelligent gas meter;

[0079] If 0 < c ≤ LEL and q min ≤ q ≤ q max , then there is a gas leak, and the leak point is located on the outlet side of the intelligent gas meter;

[0080] If c > LEL and q = 0, there is a gas leak, and the leak point is on the inlet side of the intelligent gas meter;

[0081] If c > LEL, q min ≤ q ≤ q max then there is a gas leak, and the leak point is on the outlet side of the intelligent gas meter;

[0082] If c > LEL and q > q max then there is a gas leak, and the leak point is on the outlet side of the intelligent gas meter.

[0083] This embodiment presents a specific technical solution for determining whether there is a gas leak. For the convenience of description, q represents the gas flow rate and c represents the gas concentration; then, the gas leak situations for 8 combinations corresponding to different magnitudes of q and c are respectively given. The 1 - 8 combinations are arranged in ascending order of the leak degree. Combinations 1 and 2 have no leak, combinations 3, 4, and 5 have a small leak, and combinations 6, 7, and 8 have a large or even serious leak. The detection results of the 8 combinations are introduced respectively below.

[0084] Combination 1: c = 0 and q = 0; Result: There is no gas leak and no gas is being used.

[0085] Combination 2: c = 0 and 0 < q min ≤ q ≤ q max , and the duration does not exceed the first threshold; Result: There is no gas leak and the user is using gas normally. Among them, q min , q max are respectively the minimum and maximum gas flow rates when the user is using gas normally with the intelligent gas meter, which can be obtained by statistically analyzing the gas flow rates for several consecutive days (such as 15 days). The first threshold can be determined according to the maximum value of the normal gas - using time, for example, 2 hours.

[0086] Combination 3: 0 < c ≤ LEL and q = 0; Result: There is a leakage risk and further confirmation is needed. Predict the time T when the gas concentration reaches LEL. If T is less than the second threshold, there is a gas leak, and the leak point is on the inlet side of the intelligent gas meter. Among them, LEL is the minimum gas concentration that causes an explosion. The second threshold is determined according to experience, for example, it can be selected as 24 hours.

[0087] Combination 4: 0 < c ≤ LEL and 0 < q ≤ q min , Result: There is a leakage risk and further confirmation is needed. Predict the time T when the gas concentration reaches LEL. If T is less than the second threshold, there is a gas leak, and the leak point is on the outlet side of the intelligent gas meter.

[0088] Combination 5: 0 < c ≤ LEL and q min≤q≤q max ; Result: There is gas leakage, and the leakage point is on the gas outlet side of the intelligent gas meter.

[0089] Combination 6: c > LEL and q = 0; Result: There is relatively severe gas leakage, and the leakage point is on the gas inlet side of the intelligent gas meter.

[0090] Combination 7: c > LEL and q min ≤q≤q max ; Result: There is relatively severe gas leakage, and the leakage point is on the gas outlet side of the intelligent gas meter. In this case, it is generally necessary to control the intelligent gas meter to directly cut off the gas valve.

[0091] Combination 8: c > 0 and q > q max ; Result: There is relatively severe gas leakage, and the leakage point is on the gas outlet side of the intelligent gas meter. In this case, it is also necessary to directly cut off the gas valve.

[0092] As an optional embodiment, the gas concentration prediction method includes:

[0093] Based on the gas mass conservation in the room, we get:

[0094]

[0095] In the formula, t is time, V is the room volume, c is the gas concentration in the room, q x is the gas leakage rate, and k is the number of air changes per hour in the room;

[0096] Solve the differential equation with c as the variable for equation (1) to obtain the prediction model of gas concentration:

[0097]

[0098] In the formula, c0 is the initial gas concentration, q x is obtained by fitting based on the gas concentrations at multiple historical moments using the least squares method.

[0099] This embodiment provides a technical solution for gas concentration prediction. First, according to the principle of gas mass conservation in the user's room, an equation including gas concentration, gas leakage rate, and time is listed, such as equation (1). k in equation (1) is the number of air changes per hour in the room, and generally 0.5 < k < 2.5. For the sake of simplifying the calculation, k and q x are regarded as fixed constants, and solve the differential equation of equation (1) to obtain the prediction model of gas concentration, as shown in equation (2), where q xThe value can be obtained by fitting the gas concentration at multiple historical moments using the least squares method. The gas concentration c at different times t can be obtained according to equation (2), or the time t corresponding to any c can be obtained by inverse calculation, for example, the time T at which the gas concentration reaches LEL. The sampling time interval and the number of data points n can be selected empirically. Figure 3 A schematic diagram of an indoor gas concentration prediction curve is given, where the vertical axis represents the gas concentration given as a volume fraction.

[0100] Figure 4 This is a schematic diagram illustrating the composition of a gas leak detection device based on a smart gas meter and a concentration sensor according to an embodiment of the present invention. The device includes:

[0101] Flow acquisition module 11 is used to acquire gas flow from smart gas meter in real time;

[0102] Concentration acquisition module 12 is used to acquire the gas concentration from the concentration measurement unit in real time;

[0103] The leakage detection module 13 is used to determine whether there is a gas leak based on the fusion of the gas flow rate and gas concentration.

[0104] The apparatus of this embodiment can be used to perform Figure 1 The technical solutions of the illustrated method embodiments are similar in principle and technical effect, and will not be described again here. The same applies to the subsequent embodiments, which will not be elaborated upon further.

[0105] As an optional embodiment, the device further includes a data uploading module for uploading the detection results of whether a gas leak exists and / or the real-time gas consumption data and gas concentration data to the host computer of the main station.

[0106] As an optional embodiment, the device further includes an alarm module, which is used to send an alarm reminder signal by the control processing unit and / or the host computer when the detection result indicates that there is a gas leak; and to send a command to the smart gas meter to cut off the gas supply solenoid valve when the leak is serious.

[0107] As an optional embodiment, the device further includes a leak location module, used to determine the approximate location of the gas leak point based on the gas flow rate and gas concentration when a gas leak is detected: located on the gas inlet side or gas outlet side of the smart gas meter.

[0108] As an optional embodiment, the determination of whether a gas leak exists based on the fusion of the gas flow rate and gas concentration specifically includes:

[0109] Let q represent the real-time gas flow rate obtained from the smart gas meter, and let c represent the real-time gas concentration in the user's room obtained from the concentration measurement unit. Based on the values ​​of q and c, determine whether a gas leak exists using the following method:

[0110] If c = 0 and q = 0, there is no gas leakage.

[0111] If c = 0 and 0 < q min ≤ q ≤ q max and the duration does not exceed the first threshold, there is no gas leakage; where q min , q max are respectively the minimum and maximum values of the gas flow rate when the smart gas meter user is using gas normally.

[0112] If 0 < c ≤ LEL and q = 0, there is a leakage risk. Further predict the time T when the gas concentration reaches LEL. If T is less than the second threshold, there is gas leakage and the leakage point is on the inlet side of the smart gas meter; where LEL is the minimum gas concentration that causes an explosion.

[0113] If 0 < c ≤ LEL and 0 < q ≤ q min , there is a leakage risk. Further predict the time T when the gas concentration reaches LEL. If T is less than the second threshold, there is gas leakage and the leakage point is on the outlet side of the smart gas meter.

[0114] If 0 < c ≤ LEL and q min ≤ q ≤ q max , there is gas leakage and the leakage point is on the outlet side of the smart gas meter.

[0115] If c > LEL and q = 0, there is gas leakage and the leakage point is on the inlet side of the smart gas meter.

[0116] If c > LEL and q min ?≤ q ≤ q max , there is gas leakage and the leakage point is on the outlet side of the smart gas meter.

[0117] If c > LEL and q > q max , there is gas leakage and the leakage point is on the outlet side of the smart gas meter.

[0118] As an optional embodiment, the gas concentration prediction method includes:

[0119] Based on the gas mass conservation in the room, we get:

[0120]

[0121] In the formula, t is time, V is the room volume, c is the gas concentration in the room, q x is the gas leakage rate, and k is the number of air changes per hour in the room.

[0122] Solve the differential equation with c as the variable for equation (1) to obtain the prediction model of the gas concentration.

[0123]

[0124] In the formula, c0 is the initial gas concentration, q x The gas concentration was obtained by fitting the data using the least squares method based on the gas concentration at multiple historical moments.

[0125] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A gas leak detection method based on a smart gas meter and a concentration sensor, characterized in that, It includes the following steps: Obtain the gas flow rate from the intelligent gas meter in real time; Obtain the gas concentration from the concentration measurement unit in real time; Based on the fusion of the gas flow rate and the gas concentration, determine whether there is a gas leak; Where: The method further includes: when it is detected that there is a gas leak, according to the gas flow rate and the gas concentration, determine the approximate location of the gas leak point: on the inlet side or the outlet side of the intelligent gas meter; The determination of whether there is a gas leak based on the fusion of the gas flow rate and the gas concentration specifically includes: Let q represent the gas flow rate obtained from the intelligent gas meter in real time, and let c represent the gas concentration in the user's room of the intelligent gas meter obtained from the concentration measurement unit in real time; determine whether there is a gas leak according to the magnitudes of q and c by the following method: If c = 0 and q = If c = 0, 0 min ≤q≤q max If the duration does not exceed the first threshold, then there is no gas leak; where q min q max These are the minimum and maximum gas flow rates for a smart gas meter user during normal gas usage, respectively.​ ​ If 0 <c≤LEL,0<q≤q min There is a risk of leakage. Further prediction is made on the time T when the gas concentration reaches LEL. If T is less than the second threshold, there is a gas leak, and the leak point is located on the gas outlet side of the smart gas meter. If 0 <c≤LEL,q min ≤q≤q max If so, there is a gas leak, and the leak point is located on the gas outlet side of the smart gas meter; ​ If c > LEL, q min ≤q≤q max If so, there is a gas leak, and the leak point is located on the gas outlet side of the smart gas meter; If c > LEL, then q > q max If so, there is a gas leak, and the leak point is located on the gas outlet side of the smart gas meter; ​ ​ In the formula, t is time, V is room volume, c is the gas concentration in the room, and q is the concentration of gas in the room. x Here, k represents the gas leakage rate, and k represents the number of air changes per hour in the room. ​ In the formula, c0 is the initial gas concentration, q x The gas concentration was obtained by fitting the data using the least squares method based on the gas concentration at multiple historical moments.

2. The gas leak detection method using a smart gas meter and concentration sensor according to claim 1, characterized in that, ​ 3. The gas leak detection method using a smart gas meter and concentration sensor according to claim 2, characterized in that, ​ 4. A gas leak detection device based on a smart gas meter and a concentration sensor, characterized in that, ​ ​ ​ ​ ​ ​ ​ ​ If c = 0, 0 min ≤q≤q max If the duration does not exceed the first threshold, then there is no gas leak; where q min q max These are the minimum and maximum gas flow rates for a smart gas meter user during normal gas usage, respectively.​ ​ If 0 <c≤LEL,0<q≤q min There is a risk of leakage. Further prediction is made on the time T when the gas concentration reaches LEL. If T is less than the second threshold, there is a gas leak, and the leak point is located on the gas outlet side of the smart gas meter. If 0 <c≤LEL,q min ≤q≤q max If so, there is a gas leak, and the leak point is located on the gas outlet side of the smart gas meter; ​ If c > LEL, q min ≤q≤q max If so, there is a gas leak, and the leak point is located on the gas outlet side of the smart gas meter; If c > LEL, then q > q max If so, there is a gas leak, and the leak point is located on the gas outlet side of the smart gas meter; ​ ​ In the formula, t is time, V is room volume, c is the gas concentration in the room, and q is the concentration of gas in the room. x Here, k represents the gas leakage rate, and k represents the number of air changes per hour in the room. Solving the differential equation with c as the variable in equation (1) yields the prediction model for gas concentration: In the formula, c0 is the initial gas concentration, q x The gas concentration was obtained by fitting the data using the least squares method based on the gas concentration at multiple historical moments.

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