Method for quickly positioning leakage point of gas pipeline

Abstract

A method for rapidly positioning a leakage point of a gas pipeline comprises the steps of equipment installation, data collection and leakage judgment, leakage point positioning, remote alarm and information transmission and field verification and repair, detection pipes are laid above the natural gas pipeline in parallel and are sequentially connected with all the equipment, and all the equipment is controlled by a PLC control system; the PLC control system collects detection data and compares the detection data with a preset safety range, and if the detection data exceed the preset safety range, gas leakage is judged; the PLC control system calculates the position relation between the leakage point and the monitoring equipment according to the mathematical model, so that the leakage point is quickly positioned; after the position of the leakage point is determined, an alarm is immediately given and sent to a remote monitoring center; and after the maintenance personnel arrives at the leakage point, the surrounding environment is rapidly detected, verified and maintained, and the leakage detection accuracy and reliability are improved through multi-parameter comprehensive monitoring and analysis in combination with the detection pipe provided with the selective permeable membrane.

Description

Technical Field

[0001] The invention relates to a method for quickly locating a leakage point in a gas pipeline, and belongs to the field of natural gas pipeline monitoring. Background Art

[0002] Traditional gas pipeline leak detection methods mainly include manual inspections, pressure monitoring, and chemical sensor detection. Manual inspections rely on visual and olfactory inspections by personnel, which are inefficient, easily affected by environmental factors, and have difficulty in timely detecting leaks in hidden areas. Although the pressure monitoring method can monitor pressure changes in the pipeline system, it cannot accurately locate the leak point and has low sensitivity to small leaks. The chemical sensor detection method requires the sensor to be installed directly on the pipeline, which is costly and has limited life and stability. These traditional methods have many limitations in practical applications and are difficult to meet the efficiency, accuracy, and real-time requirements of modern gas pipeline safety monitoring. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a method for quickly locating a gas pipeline leak point, so as to solve the problem that the existing gas leak cannot be quickly and accurately located.

[0004] In order to achieve the above object, the present invention is implemented through the following technical solutions: a method for quickly locating a gas pipeline leak point, comprising: S1. Equipment installation: The detection tube is laid parallel to the natural gas pipeline. One end of the detection tube is connected to the drying oven, and the other end is connected to the methane analyzer, flow meter, electric valve, vacuum tank and vacuum pump in sequence. Each device is controlled by the PLC control system and connected to the communication module. S2. Data collection and leakage judgment: The PLC control system collects the detection data of each sensor or device, and compares the operating data with the preset safety range. If it exceeds the safety range, it is judged as a gas leak; S3. Leak point location: The PLC control system uses the mathematical model for positioning in the PLC control system based on the gas concentration distribution pattern detected by the sensor and the propagation time difference of the physical quantity change to calculate the positional relationship between the leak point and the monitoring equipment, thereby quickly locating the leak point. S4. Remote alarm and information transmission: After the PLC control system locates the leakage point, it will immediately alarm and send the information to the remote monitoring center through the built-in communication module; S5. On-site verification and repair: After the maintenance personnel arrive at the leak point, they will conduct a quick inspection and verification of the surrounding environment to further determine the specific location, and adjust the repair plan in a timely manner based on the real-time monitoring data of the PLC control system.

[0005] Furthermore, in S1, the detection tube is a thin film tube and is wrapped with a selective permeation membrane made by modifying sodium lignin sulfonate and polydimethyl alkylene oxide. A temperature sensor and a pressure sensor are also provided in the vacuum tank.

[0006] Furthermore, the methane gas permeation rate of the selective permeation membrane is related to the air flow rate in the detection tube and the pressure in the vacuum tank.

[0007] Furthermore, under the same pressure, the methane gas permeation rate is proportional to the airflow rate in the detection tube, and under the same airflow rate, the methane gas permeation rate is proportional to the pressure in the vacuum tank.

[0008] Furthermore, in said S2, the sensors and devices include a pressure sensor, a temperature sensor, a flow meter and a methane analyzer.

[0009] Furthermore, in said S2, the preset safety range is determined based on historical data statistics under normal operating conditions of the gas pipeline, which includes a gas concentration threshold, a flow rate change rate, a pressure range, and a temperature range.

[0010] Furthermore, in S3, the mathematical model calculates the distance the leaked gas flows in the detection tube through the feedback values ​​from the methane analyzer and the flow meter.

[0011] Furthermore, in said S3, the physical quantities include temperature, pressure and sound waves, which are used to assist in leakage judgment.

[0012] Furthermore, in S4, the communication module is one of GPRS, LTE or satellite communication modules.

[0013] Furthermore, in S5, the operator uses a handheld gas detector to quickly detect and verify the environment around the leakage point.

[0014] The beneficial effects of the present invention are: 1. This application is based on the principle of natural gas diffusion. The core component is a detection tube wrapped with a selective permeation membrane made of sodium lignin sulfonate and polydimethyl alkylene oxide. The detection tube is laid in parallel above the gas pipeline. The methane analyzer detects the leaked gas, and the leakage data and leakage point are obtained through the PLC control system. The real-time data is transmitted remotely through the communication module, and the operator is notified efficiently and quickly to carry out maintenance.

[0015] 2. This application uses advanced mathematical models and sensor technology to comprehensively consider multiple factors such as the flow velocity and pressure of gas in the pipeline, the relative position of the detection tube and the gas pipeline, and the time difference of the change of physical quantities, thereby achieving high-precision positioning of the leakage point. Through comprehensive monitoring and analysis of multiple parameters, the accuracy and reliability of leak detection are improved, and false alarms and missed alarms caused by fluctuations in a single parameter are avoided, thereby ensuring the stable operation of the system and reducing unnecessary maintenance and inspection work.

[0016] 3. This application embeds a communication module (such as GPRS, LTE or satellite communication module) to realize the remote monitoring function of the system. The monitoring center can grasp the operating status and leakage of the gas pipeline in real time, conduct centralized management and decision-making analysis, and can timely understand the operating status of the pipeline without the need for frequent manual inspections on site, which greatly improves management efficiency and reduces labor costs. At the same time, it can ensure a rapid response when a leak occurs and take timely measures to improve the safety and reliability of the gas pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings: Figure 1 This is a schematic diagram of the structure of a device for quickly locating a gas pipeline leak point according to the present invention; Figure 2 This is a flow chart of a method for quickly locating a gas pipeline leakage point according to the present invention; Figure 3 is the concentration curve of natural gas after treatment; Figure 4 is the concentration curve of untreated natural gas.

[0018] The reference numerals are: 1. natural gas pipeline; 2. detection tube; 3. drying oven; 4. methane analyzer; 5. flow meter; 6. electric valve; 7. vacuum tank; 8. vacuum pump; 9. PLC control system. DETAILED DESCRIPTION

[0019] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0020] like Figure 1 、 Figure 2 As shown, the present invention provides a method and technical solution for quickly locating a gas pipeline leak point, which includes: S1. Equipment Installation: A detection tube 2 is laid parallel to and above the natural gas pipeline 1. One end of the detection tube 2 is connected to a drying oven 3, and the other end is sequentially connected to a methane analyzer 4, a flow meter 5, an electric valve 6, a vacuum tank 7, and a vacuum pump 8. Each device is controlled by a PLC control system 9 and is connected to a communication module. S2. Data collection and leakage judgment: The PLC control system 9 collects the detection data of each sensor or device and compares the operating data with the preset safety range. If it exceeds the safety range, it is judged as a gas leak; S3. Leak point location: The PLC control system 9 calculates the positional relationship between the leak point and the monitoring equipment based on the gas concentration distribution pattern detected by the sensor and the propagation time difference of the physical quantity change, using the mathematical model implemented in the PLC control system 9 to quickly locate the leak point. S4, remote alarm and information transmission: After the PLC control system 9 determines the location of the leak point, it will immediately alarm and send the information to the remote monitoring center through the built-in communication module; S5. On-site verification and repair: After the maintenance personnel arrive at the leak point, they conduct a quick inspection and verification of the surrounding environment to further determine the specific location, and adjust the repair plan in a timely manner based on the real-time monitoring data of the PLC control system 9.

[0021] In order to facilitate the absorption and diffusion of methane gas, in S1, the detection tube 2 is a thin film tube and is wrapped with a selective permeation membrane made by modifying sodium lignin sulfonate and polydimethyl alkylene oxide. A temperature sensor and a pressure sensor are also provided in the vacuum tank.

[0022] In order to better collect the amount of methane gas leakage, the methane gas permeation of the selective permeation membrane is related to the air flow rate in the detection tube and the pressure in the vacuum tank.

[0023] In order to generate the optimal parameters for detecting leakage, under the same pressure, the methane gas permeation is proportional to the air flow rate in the detection tube 2, and under the same air flow rate, the methane gas permeation is proportional to the pressure in the vacuum tank 7.

[0024] In order to perform real-time monitoring, in S2 , the sensors and devices include a pressure sensor, a temperature sensor, a flow meter 5 and a methane analyzer 4 .

[0025] In order to ensure that the natural gas is within a safe range, in S2, the preset safety range is determined based on historical data statistics under normal operating conditions of the gas pipeline, which includes gas concentration threshold, flow rate change rate, pressure range and temperature range.

[0026] In order to quickly locate the leakage point, in S3 , the mathematical model calculates the distance the leaked gas flows in the detection tube 2 through the feedback values ​​of the methane analyzer 4 and the flow meter 5 .

[0027] In order to increase the accuracy of leak detection, in S3, the physical quantities include temperature, pressure and sound waves, which are used to assist in leak judgment.

[0028] In order to quickly transmit the location of the leakage point, in S4, the communication module is one of GPRS, LTE or satellite communication modules.

[0029] In order to accurately locate the leakage point, in S5, the operator uses a handheld gas detector to quickly detect and verify the environment around the leakage point.

[0030] Example 1: (1) Positioning model distance calculation: like Figure 3 and Figure 4 As shown, after detecting a gas leak, the PLC control system 9 will automatically start the mathematical model for leak point positioning, and use the start time as the timing start point t1, and the peak point of the leaked gas concentration as the timing end point t2. The time difference between the two is △T, which is used to represent the time the leaked mixed gas flows in the pipeline.

[0031] The methane analyzer 4 is used to collect the concentration of the processed leaked natural gas in the detection tube 2, and the flow meter 5 is used to convert the collected leakage gas concentration data into the velocity v of the leakage gas flowing in the detection tube 2, and calculate the distance S of the leakage gas flowing in the pipeline through the formula S=v*△T.

[0032] (2) Calculation of peak point of leakage gas concentration: The concentration of untreated natural gas collected by the methane analyzer 4 is analyzed, and the area where the peak point appears is converted into a separate area, and the area size of the peak area is compared one by one.

[0033] During the comparison process, if the peak area is found to be gradually increasing, it means that the comparison peak area is not the block where the leakage point is located; continue to compare until the peak area is found to be decreasing and gradually decreasing, it means that the maximum peak point is in this area, and the maximum value point in this area is the leakage point.

[0034] That is: take the entire time period [t1, t3] as the analysis area, divide the area into several small areas, and obtain the integral numerical solution of the entire interval by giving the numerical solution of each small area. Let t i =t1+(i-1)h,h=(t i -t1) / (n-1), where n is the number of small blocks and i is a natural number: ; The f(x) in the above formula is the approximate function of the curve after transformation as shown below: ; Example 2: The leak point location of this application specifically includes the following steps: 1. Data preprocessing: (1) Data acquisition: The PLC control system 9 collects data from various sensors and equipment in real time, including detection data from the flow meter 5, pressure sensor, temperature sensor, and methane analyzer 4; (2) Data cleaning: remove outliers from the collected data to further ensure the accuracy and reliability of the data; (3) Data standardization: Standardize the data collected by different sensors to a unified dimension and range to facilitate subsequent analysis.

[0035] 2. Leakage judgment: (1) Threshold comparison: The collected operating data is compared with the preset safety range. The preset safety range is determined based on the statistical analysis of historical data under the normal operating state of the natural gas pipeline 1, including gas concentration threshold, flow rate change rate, pressure range and temperature range; (2) Abnormality detection: If the gas concentration exceeds the set threshold or the rate of change of flow, pressure, or temperature exceeds the preset range, the PLC control system 9 determines that it is a gas leak.

[0036] 3. Leak point location: (1) Gas concentration analysis: Determine the approximate area of ​​the leakage point based on the gas concentration distribution pattern detected by the methane analyzer 4; (2) Analysis of physical quantity changes: Combined with the propagation time difference of physical quantity changes such as temperature, pressure and sound waves sensed by the sensor, the location of the leak point is further refined; (3) Mathematical model calculation: The numerical values ​​collected by the methane analyzer 4 and the flow meter 5 are combined with the mathematical model of positioning to calculate the distance the leaked gas flows in the pipeline.

[0037] 4. Positioning result verification: (1) Multi-parameter fusion: Fusion of multi-parameter data such as gas concentration, flow, pressure and temperature to verify the accuracy of positioning results; (2) Historical data comparison: Compare the current positioning results with the data of historical leakage events to further confirm the location of the leakage point; (3) Manual positioning detection: The operator uses a handheld gas detector to quickly detect and verify the environment around the leak point, accurately locate the leak point, and promptly feedback the location information. The location information is updated as historical data to the PLC control system 9 to facilitate real-time updating of the system's database, providing more accurate positioning results for subsequent work.

[0038] Through the above steps, this application can quickly and accurately locate the leakage point of the gas pipeline and ensure the safe operation of the gas pipeline. This method not only improves the efficiency and accuracy of leak detection, but also provides strong support for timely repair of the leakage point, effectively reducing the safety risks and economic losses caused by gas leakage.

[0039] Example 3: The detection tube 2 of the present application is wrapped with a selective permeation membrane made by modifying sodium lignin sulfonate and polydimethyl alkylene oxide. By utilizing the selective permeability principle of a semipermeable membrane, a special film tube is made to have selective permeability to hydrocarbon gases (methane, ethane), thereby accurately and efficiently detecting gas leaks.

[0040] The comparative test results of the selective permeable membrane are as follows: The selective permeable membrane modified with polydimethyl alkylene oxide in this application exhibits excellent characteristics in multiple key performance indicators. In terms of water permeability, the membrane allows hydrocarbon molecules to pass through efficiently, ensuring smooth hydrocarbon molecule penetration. Its air permeability is also excellent, allowing gas molecules to pass freely, which is crucial in scenarios involving gas exchange or separation, accelerating gas transmission efficiency and improving overall process efficiency. In terms of tensile strength, the modified membrane has high mechanical strength and is not easily deformed or damaged by external tension, ensuring its integrity and reliability under complex working conditions and stress conditions, and extending its service life. In terms of temperature resistance, the membrane can maintain stable performance over a wide temperature range and can function normally in both high and low temperature environments. This greatly enhances its scope of application and environmental adaptability, enabling it to meet the needs of use under different temperature conditions. In terms of the key indicator of air permeability resistance, it exhibits low resistance, which means that gas can pass through the membrane layer with low energy loss. This not only helps to increase the gas permeation rate, but also reduces energy consumption and improves the energy efficiency of related equipment and systems. In summary, the selective permeable membrane modified with polydimethyl alkylene oxide reagent has outstanding performance in many aspects such as water permeability, air permeability, tensile strength, temperature resistance and air permeability resistance, making it an ideal choice for high-performance separation and permeation detection tube 2.

[0041] This application is based on the principle of natural gas diffusion. The core component is a detection tube 2 with an external coating made of a selective permeation membrane modified from sodium lignin sulfonate and polydimethyl alkylene oxide. The detection tube 2 is laid in parallel above the natural gas pipeline 1. The leaked gas is detected by a methane analyzer 4, and the leakage data and leakage point are obtained through the PLC control system 9. The real-time data is remotely transmitted through the communication module, and the operator is notified efficiently and quickly to perform maintenance.

[0042] With the help of advanced mathematical models and sensor technology, this application comprehensively considers multiple factors such as the flow velocity and pressure of the gas in the pipeline, the relative position of the detection tube 2 and the natural gas pipeline 1, and the time difference of the change of physical quantities, thereby achieving high-precision positioning of the leakage point. Through comprehensive monitoring and analysis of multiple parameters, the accuracy and reliability of leak detection are improved, false alarms and missed alarms caused by fluctuations in a single parameter are avoided, the stable operation of the system is ensured, and unnecessary maintenance and inspection work is reduced.

[0043] This application embeds a communication module (such as GPRS, LTE or satellite communication module) to realize the remote monitoring function of the system. The monitoring center can grasp the operating status and leakage of the natural gas pipeline 1 in real time, conduct centralized management and decision-making analysis, and can timely understand the operating status of the pipeline without the need for frequent manual inspections on site, greatly improving management efficiency and reducing labor costs. At the same time, it can ensure a rapid response when a leak occurs and take timely measures to improve the safety and reliability of the natural gas pipeline 1.

[0044] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all perspectives, the embodiments should be regarded as illustrative and non-restrictive. The scope of the present invention is defined by the appended claims, not the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be included within the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0045] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for quickly locating a gas pipeline leak, characterized by: It includes: S1. Equipment installation: The detection tube (2) is laid parallel to the natural gas pipeline (1). One end of the detection tube (2) is connected to the drying box (3), and the other end is connected to the methane analyzer (4), flow meter (5), electric valve (6), vacuum tank (7) and vacuum pump (8) in sequence. Each device is controlled by the PLC control system (9) and connected to the communication module; S2. Data collection and leakage judgment: The PLC control system (9) collects the detection data of each sensor or device and compares it with the preset safety range based on the operating data. If it exceeds the safety range, it is judged as a gas leak; S3. Leakage point location: The PLC control system (9) calculates the positional relationship between the leakage point and the monitoring equipment based on the gas concentration distribution law detected by the sensor and the propagation time difference of the physical quantity change, and uses the mathematical model for positioning in the PLC control system (9) to achieve rapid positioning of the leakage point; S4. Remote alarm and information transmission: After the PLC control system (9) determines the location of the leakage point, it immediately alarms and sends the information to the remote monitoring center through the built-in communication module; S5. On-site verification and repair: After the maintenance personnel arrive at the leak point, they conduct a quick inspection and verification of the surrounding environment to further determine the specific location, and adjust the repair plan in a timely manner based on the real-time monitoring data of the PLC control system (9).

2. A method for quickly locating a gas pipeline leak according to claim 1, characterized in that: In the above S1, the detection tube (2) is a thin film tube and is wrapped with a selective permeation membrane made by modifying sodium lignin sulfonate and polydimethyl alkylene oxide. A temperature sensor and a pressure sensor are also provided in the vacuum tank.

3. A method for quickly locating a gas pipeline leak according to claim 2, characterized in that: The methane gas permeation rate of the selective permeation membrane is related to the air flow rate in the detection tube and the pressure in the vacuum tank.

4. A method for quickly locating a gas pipeline leak according to claim 3, characterized in that: Under the same pressure, the methane gas permeation amount is proportional to the air flow rate in the detection tube (2); under the same air flow rate, the methane gas permeation amount is proportional to the pressure in the vacuum tank (7).

5. The method for quickly locating a gas pipeline leak according to claim 2, characterized in that: In said S2, the sensors and devices include a pressure sensor, a temperature sensor, a flow meter (5) and a methane analyzer (4).

6. The method for quickly locating a gas pipeline leak according to claim 1, characterized in that: In said S2, the preset safety range is determined based on historical data statistics under normal operating conditions of the gas pipeline, which includes a gas concentration threshold, a flow rate change rate, a pressure range, and a temperature range.

7. The method for quickly locating a gas pipeline leak according to claim 1, characterized in that: In the above-mentioned S3, the mathematical model calculates the distance that the leaked gas flows in the detection tube (2) by using the numerical values ​​fed back by the methane analyzer (4) and the flow meter (5).

8. The method for quickly locating a gas pipeline leak according to claim 1, characterized in that: In the above-mentioned S3, the physical quantities include temperature, pressure and sound waves, which are used to assist in leakage judgment.

9. The method for quickly locating a gas pipeline leak according to claim 1, characterized in that: In the above S4, the communication module is one of GPRS, LTE or satellite communication modules.

10. The method for quickly locating a gas pipeline leak according to claim 1, characterized in that: In S5, the operator uses a handheld gas detector to quickly detect and verify the environment around the leakage point.

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