Fiber-optic sensing based natural gas pipeline leak detection system and method

Abstract

The application discloses a natural gas pipeline leakage detection system and method based on optical fiber sensing, relates to the technical field of pipeline leakage detection, and is used for acquiring the number of sampling points arranged on a pipeline through an acquisition module, numbering a plurality of sampling points, controlling the sampling points to be opened for detection at intervals based on the number of sampling points arranged on the pipeline and numbering information through an initial control module, judging whether the pipeline has a leakage problem through an analysis module after comprehensively analyzing optical fiber data and a plurality of data, and opening the adjacent sampling points of the sampling point for detection through an automatic control module when it is judged that the pipeline has a leakage problem at the sampling point. The detection system is opened for the sampling points at intervals when starting to operate initially, so that the energy consumption of the detection system is effectively reduced, and when it is detected that the pipeline has a leakage phenomenon at the sampling point, the adjacent sampling points of the sampling point are opened for auxiliary detection to avoid no detection, so that the accuracy of the detection system is improved.

Description

Technical Field

[0001] This invention relates to the field of pipeline leak detection technology, and specifically to a natural gas pipeline leak detection system and method based on fiber optic sensing. Background Technology

[0002] Natural gas is an important energy resource, widely used in heating, power generation, industrial production and household gas use. However, leaks in natural gas pipeline systems can lead to environmental pollution, personal injury and property damage, so the safe operation of pipelines is crucial.

[0003] Fiber optic sensing technology is a highly sensitive monitoring technology that detects changes in the surrounding environment based on the propagation characteristics of light. In natural gas pipeline leak detection, optical fibers can be deployed around or inside the pipeline to detect signs of gas leaks by monitoring changes in light signals. This technology has advantages such as high sensitivity, real-time performance, and wide coverage.

[0004] The existing technology has the following shortcomings:

[0005] Existing detection systems typically involve setting up multiple detection points on natural gas pipelines. Each detection point is equipped with fiber optic sensors both inside and outside the pipeline for leak detection. However, in daily use, if all fiber optic sensors at all detection points are turned on, it will result in energy waste and increase detection costs. If too few detection points are set up, it may lead to a decrease in detection accuracy.

[0006] Therefore, this invention proposes a natural gas pipeline leak detection system and method based on fiber optic sensing, which can intelligently adjust the number of detection points and the on / off state of the fiber optic sensors, ensuring detection accuracy while avoiding energy waste. Summary of the Invention

[0007] The purpose of this invention is to provide a natural gas pipeline leak detection system and method based on fiber optic sensing to address the shortcomings of the prior art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a natural gas pipeline leak detection system based on optical fiber sensing, comprising an acquisition module, an initial control module, an optical fiber detection module, a data acquisition module, an analysis module, and an automatic control module;

[0009] Acquisition module: used to acquire the number of sampling points set on the pipeline and number the multiple sampling points. Each sampling point is equipped with an acquisition module and an optical fiber detection module.

[0010] Initial control module: Based on the number and numbering information of the sampling points set on the pipeline, it controls the interval at which the sampling points start detection;

[0011] Fiber optic detection module: Acquires fiber optic data related to pipeline leaks during natural gas transmission;

[0012] Acquisition module: Located near the fiber optic detection module, it is used to acquire multiple data related to pipeline leaks;

[0013] Analysis module: Determines whether there is a leak in the pipeline after comprehensively analyzing fiber optic data and multiple data points;

[0014] Automatic control module: When a leak is detected in the pipeline at a certain sampling point, the adjacent sampling points are activated for detection to determine whether there is any false detection.

[0015] Preferably, the fiber optic detection module acquires fiber optic data related to pipeline leakage when natural gas is being transported through the pipeline. The fiber optic data includes the pipeline strain phase index.

[0016] The acquisition module is located near the fiber optic detection module and is used to acquire multiple data related to pipeline leakage, including pipeline pressure fluctuation amplitude and natural gas flow velocity fluctuation amplitude.

[0017] Preferably, the analysis module calculates the pipeline strain phase index, pipeline pressure fluctuation amplitude, and natural gas flow velocity fluctuation amplitude to obtain the leakage coefficient xl. s The expression is:

[0018]

[0019] In the formula, Let represent the pipeline strain phase index, gy represent the pipeline pressure fluctuation amplitude, gl represent the natural gas flow velocity fluctuation amplitude, and α, β, and γ represent the proportionality coefficients of the pipeline strain phase index, pipeline pressure fluctuation amplitude, and natural gas flow velocity fluctuation amplitude, respectively, with α, β, and γ all being greater than 0.

[0020] Preferably, the analysis module obtains the leakage coefficient xl s Then, the leakage coefficient xl s Compared with the preset leakage threshold, if the leakage coefficient xl s <Leakage threshold, indicating that there is no leakage problem in the pipeline;

[0021] If the leakage coefficient xl s If the value is greater than or equal to the leakage threshold, it indicates that there is a leakage problem in the pipeline.

[0022] Preferably, when a leak is detected in the pipeline at a certain sampling point, the automatic control module activates adjacent sampling points for detection to determine whether there is a false positive. This includes the following steps:

[0023] If the leakage coefficient at adjacent sampling points is xl sIf the leakage threshold is exceeded, other sampling points near the leak detection sampling point will be activated. If the leakage coefficient at other sampling points is less than the threshold, the process will continue. s If the leakage coefficient at any sampling point is less than the leakage threshold, it is determined that there is a false alarm. s If the value is greater than or equal to the leakage threshold, it is determined that there is no false detection.

[0024] If the leakage coefficient at adjacent sampling points is xl s If the result is greater than or equal to the leakage threshold, it is determined that there is no false detection.

[0025] Preferably, the expression for calculating the strain phase index of the pipeline is:

[0026]

[0027] In the formula, The strain phase index of the pipeline. λ is the wavelength of the light from the fiber optic sensor, and L is the location of the strain scattering event on the pipe.

[0028] Preferably, the formula for calculating the amplitude of the pipeline pressure fluctuation is:

[0029] gy=|V 实际 -V 目标 |;

[0030] In the formula, gy is the amplitude of pipeline pressure fluctuation, and V 实际 V represents the actual measured pipe pressure. 目标 This indicates the expected or set target pipeline pressure.

[0031] Preferably, the formula for calculating the amplitude of the natural gas flow velocity fluctuation is:

[0032] gl=|P 实际 -P 目标 |;

[0033] In the formula, gl is the amplitude of natural gas flow velocity fluctuation, and P 实际 P represents the actual measured natural gas flow rate. 目标 This indicates the expected or set target natural gas flow rate.

[0034] This invention also provides a method for detecting natural gas pipeline leaks based on fiber optic sensing, the method comprising the following steps:

[0035] S1: The acquisition end obtains the number of sampling points set on the pipeline and numbers the multiple sampling points. Each sampling point is equipped with a sensing device and an optical fiber detection device.

[0036] S2: Based on the number and numbering information of the sampling points set on the pipeline, control the interval between sampling points to start detection;

[0037] S3: When natural gas is being transported through pipelines, fiber optic detection equipment acquires fiber optic data related to pipeline leaks;

[0038] S4: The sensing device is located near the fiber optic detection module to acquire multiple data related to pipeline leaks;

[0039] S5: After comprehensively analyzing fiber optic data and multiple data points, determine whether there is a leak in the pipeline;

[0040] S6: When a leak is detected at a certain sampling point, start testing at the adjacent sampling points to determine if there is any false detection.

[0041] The technical effects and advantages provided by the present invention in the above technical solution are as follows:

[0042] 1. This invention uses an acquisition module to obtain the number of sampling points set on the pipeline and number them. An initial control module, based on the number and number of sampling points, controls the sampling points to activate at intervals for detection. An analysis module comprehensively analyzes fiber optic data and multiple data sources to determine if there is a leak in the pipeline. When a leak is detected at a sampling point, the automatic control module activates adjacent sampling points for detection. During initial startup, the detection system activates sampling points at intervals to effectively reduce energy consumption. When a leak is detected at a sampling point, adjacent sampling points are activated for auxiliary detection to avoid missing any points, thereby improving the accuracy of the detection system. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0044] Figure 1 This is a system module diagram of the present invention. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Example 1: Please refer to Figure 1 As shown, the natural gas pipeline leak detection system based on fiber optic sensing described in this embodiment includes an acquisition module, an initial control module, a fiber optic detection module, a data acquisition module, an analysis module, and an automatic control module.

[0047] Acquisition Module: Used to acquire the number of sampling points set on the pipeline and number the multiple sampling points. Each sampling point is equipped with an acquisition module and an optical fiber detection module. The number and numbering information of the sampling points are sent to the automatic control module, including the following steps:

[0048] Install the data acquisition module and the fiber optic detection module:

[0049] Install data acquisition modules and fiber optic detection modules on the pipeline, ensuring they are correctly connected and functioning properly. These modules can be used to monitor the pipeline's status, temperature, pressure, humidity, or other parameters that require monitoring.

[0050] Determine the number of sampling points:

[0051] Use appropriate methods to determine the number of sampling points to be set on the pipeline. This can be based on the pipeline's length, diameter, internal environment, or testing requirements.

[0052] Assign a unique number to each sampling point:

[0053] Assign a unique numeric or character number to each sampling point. Ensure these numbers are sufficiently unique for identification during subsequent data processing. Software or hardware tools can be used to record and manage these numbers.

[0054] Sampling point information is sent to the automatic control module:

[0055] A data transmission module is installed at each sampling point. This module is responsible for sending the sampling point's number information, along with relevant information from the acquisition module and fiber optic detection module, to the automatic control module. This can be achieved through wireless communication, wired communication, or other suitable communication methods.

[0056] Data transmission protocol:

[0057] Determine the data format and protocol for transmitting sampling point information. Typically, a data structure needs to be defined, including fields such as sampling point number, acquisition module information, and fiber optic detection module information. Ensure the automatic control module can parse and process this data.

[0058] The automatic control module receives and processes data:

[0059] Configure a program in the automatic control module to receive and process sampling point information. This program should be responsible for parsing the received information, associating the numbers with the corresponding acquisition modules and fiber optic detection modules, and storing this information for subsequent pipeline monitoring and management.

[0060] Testing and maintenance:

[0061] After installation and configuration, test the system to ensure that the sampling point information can be transmitted and processed correctly. Perform regular system maintenance to ensure the normal operation of all sampling points and related equipment.

[0062] The initial control module, based on the number and numbering of sampling points set on the pipeline, controls the interval at which sampling points are activated for detection (for example, after activating the first sampling point, the second sampling point is not activated, the third sampling point is activated, and so on). This includes the following steps:

[0063] Receive sampling point information:

[0064] The automatic control module should receive the number and number of sampling points from the acquisition module. This information will be used to determine which sampling points need to be detected within a specific time period.

[0065] Define the detection interval:

[0066] Determine the detection interval between each sampling point and when to start detection. This can be defined based on time, event triggering, or other conditions. For example, the detection interval for each sampling point can be set to 10 minutes, and detection can begin at the start time.

[0067] Programming control logic:

[0068] Write control logic in the initial control module to determine which sampling points should be detected within the current time period based on their numbering information. This can be achieved using conditional statements, loops, or other programming structures.

[0069] Start detection:

[0070] When the initial control module determines that a sampling point requires detection, it sends a command to the corresponding acquisition module and fiber optic detection module to initiate detection. This will activate the relevant equipment to begin data acquisition and leak detection.

[0071] Timed control:

[0072] Use timers or other time control mechanisms to ensure that detection of the current sampling point is turned off after each detection time interval and detection of the next sampling point is turned on in the next time interval.

[0073] Data recording and processing:

[0074] During the inspection process, the automatic control module should monitor and record the collected data for subsequent analysis and reporting. This data may include pipeline status, leaks, or other relevant parameters.

[0075] Execute in a loop:

[0076] Continue executing the control logic in a loop until all sampling points have been detected or detection stops as required.

[0077] Exception handling:

[0078] Implement an exception handling mechanism in the control module to deal with possible faults or errors, and ensure the reliability and stability of the system.

[0079] Maintenance and monitoring:

[0080] Regularly maintain and monitor the initial control module to ensure its proper functioning. Address any faults or anomalies promptly to minimize system downtime.

[0081] Fiber optic detection module: When natural gas is being transported through pipelines, it acquires fiber optic data related to pipeline leaks and sends the fiber optic data to the analysis module;

[0082] Acquisition module: Located near the fiber optic detection module, it is used to acquire multiple data related to pipeline leaks and send the data to the analysis module;

[0083] Analysis module: After comprehensively analyzing fiber optic data and multiple data sources, it determines whether there is a leak in the pipeline and sends the result to the automatic control module;

[0084] Automatic control module: When a leak is detected at a sampling point, the module activates adjacent sampling points for detection (if a sampling point has only one adjacent sampling point, that adjacent sampling point is activated; if a sampling point has two adjacent sampling points, both adjacent sampling points are activated). The module checks for false positives. If a leak is confirmed, it sends an alert signal to the management center, including the following steps:

[0085] Check pipeline condition:

[0086] At each sampling point, the fiber optic detection module and acquisition module continuously monitor the pipeline's status. When an abnormal signal is detected at a sampling point, indicating a potential leak, further processing will be triggered.

[0087] Determine adjacent sampling points:

[0088] Based on the pipeline's structure and layout information, the automatic control module determines which sampling points are adjacent to the current sampling point. Typically, a sampling point can have one or two adjacent sampling points, depending on the pipeline's connection method.

[0089] Enable adjacent sampling point detection:

[0090] When a leakage problem is detected at a sampling point, the automatic control module should send a command to activate the adjacent sampling points for detection. This can be achieved by sending signals or commands to the control modules of the adjacent sampling points.

[0091] Detect and confirm the leak:

[0092] After detection is initiated at adjacent sampling points, the corresponding data is monitored and recorded. The automatic control module needs to analyze this data to confirm whether a leak exists. This is achieved by comparing changes and characteristics in the data, ensuring accurate confirmation of the leak.

[0093] Send an alert signal:

[0094] If the automatic control module detects a leak in the pipeline, it should send an alert signal to the management center. This can be achieved through network communication or other appropriate communication methods. The alert signal should include information about the location, severity, and potential impact of the leak.

[0095] False positive detection:

[0096] Before sending an alert signal, the automatic control module can perform false alarm detection. This can be achieved through further data analysis and verification to ensure that the leak detection is accurate and not a false alarm caused by system noise or other interference.

[0097] Emergency measures:

[0098] After sending a warning signal, the automatic control module can trigger corresponding emergency measures, such as closing valves, notifying maintenance personnel, or activating the emergency discharge system, to minimize the impact of the leak.

[0099] Log recording and reporting:

[0100] All event data and warning signals are recorded, and reports are generated for subsequent analysis and review. This helps improve the performance and reliability of the pipeline monitoring system.

[0101] This application uses an acquisition module to obtain the number of sampling points set on the pipeline and number them. An initial control module, based on the number and number of sampling points, controls the sampling points to activate at intervals for detection. An analysis module comprehensively analyzes fiber optic data and multiple data sources to determine if there is a leak in the pipeline. When a leak is detected at a sampling point, the automatic control module activates adjacent sampling points for detection. During initial startup, the detection system activates sampling points at intervals to effectively reduce energy consumption. When a leak is detected at a sampling point, adjacent sampling points are activated for auxiliary detection to avoid missing any points, thereby improving the accuracy of the detection system.

[0102] Example 2: When natural gas is transported through a pipeline, the fiber optic detection module acquires fiber optic data related to pipeline leakage. This data includes the pipeline strain phase index, calculated as follows:

[0103]

[0104] In the formula, The strain phase index of the pipeline. λ is the wavelength of the light from the fiber optic sensor, and L is the location of the strain scattering event on the pipe.

[0105] The larger the strain phase index of a pipe, the greater the strain on the pipe surface. In distributed fiber optic sensors, detecting the strain on the pipe surface by measuring the phase change of the optical signal is a common method. When a pipe is subjected to strain or deformation, the light wave in the optical fiber will undergo a phase change. This phase change is usually related to the intensity and location of the strain. Generally speaking, the larger the value of the phase change, the greater the strain at the location monitored by the fiber optic sensor. This can be used to detect the strain on the pipe surface and may indicate that there is a problem with the pipe, such as the pipe being affected by external forces or having a leak.

[0106] The acquisition module is located near the fiber optic detection module and is used to acquire multiple data related to pipeline leakage, including pipeline pressure fluctuation amplitude and natural gas flow velocity fluctuation amplitude.

[0107] The formula for calculating the amplitude of pipeline pressure fluctuation is:

[0108] gy=|V 实际 -V 目标 |;

[0109] In the formula, gy is the amplitude of pipeline pressure fluctuation, and V 实际 V represents the actual measured pipe pressure. 目标 Indicates the expected or set target pipeline pressure;

[0110] The larger the amplitude of pipeline pressure fluctuation, the more it indicates:

[0111] Abnormal pressure fluctuations: Large pressure deviations may indicate abnormal pressure fluctuations in the pipeline system, which may be caused by valve operation, equipment failure, or external factors in the pipeline system.

[0112] Leakage or damage: Increased pressure deviation in a pipeline system may also be caused by leakage or damage to the pipeline system. Leakage will cause a decrease in internal pressure in the pipeline, thereby causing deviation.

[0113] Pressure control issues: Increased pressure deviation in a piping system may indicate a pressure control problem, which could be caused by a malfunction or improper adjustment of the pressure regulator.

[0114] Abnormal operation: Abnormal operation of the piping system may lead to an increase in pressure deviation, which may include valve operation errors, pipeline overload or overheating.

[0115] The formula for calculating the amplitude of natural gas flow velocity fluctuation is:

[0116] gl=|P 实际 -P 目标 |;

[0117] In the formula, gl is the amplitude of natural gas flow velocity fluctuation, and P 实际 P represents the actual measured natural gas flow rate. 目标 Indicates the expected or set target natural gas flow rate;

[0118] Abnormal flow rate: A large flow rate deviation may indicate that the natural gas flow rate in the pipeline is significantly abnormal compared to the target flow rate within the normal operating range. This may be due to blockage inside the pipeline, increased resistance, equipment failure, or other reasons.

[0119] Pipeline leak: An increased deviation in the natural gas flow rate in a pipeline system may also be a sign of a leak. A leak will cause an abnormal increase in flow rate because some natural gas escapes through the leak point, thereby reducing the flow rate.

[0120] Flow rate control issues: Large flow rate deviations may indicate problems with flow rate control in the pipeline system. This could be caused by improper valve operation, control system malfunctions, or human error.

[0121] Poor pipeline condition: Damage, blockage, or corrosion inside the pipeline can cause significant flow rate deviations, which can affect the flow of natural gas in the pipeline and thus cause abnormal flow rates.

[0122] The analysis module comprehensively analyzes fiber optic data and multiple data sources to determine whether there is a leak in the pipeline.

[0123] The analysis module calculates the leakage coefficient xl by comprehensively analyzing the pipeline strain phase index, pipeline pressure fluctuation amplitude, and natural gas flow velocity fluctuation amplitude. s The expression is:

[0124]

[0125] In the formula, Let represent the pipeline strain phase index, gy represent the pipeline pressure fluctuation amplitude, gl represent the natural gas flow velocity fluctuation amplitude, and α, β, and γ represent the proportionality coefficients of the pipeline strain phase index, pipeline pressure fluctuation amplitude, and natural gas flow velocity fluctuation amplitude, respectively, with α, β, and γ all being greater than 0.

[0126] The analysis module obtains the leakage coefficient xl s Then, the leakage coefficient xl s Compared with the preset leakage threshold, if the leakage coefficient xl s <Leakage threshold, indicating that there is no leakage problem in the pipeline;

[0127] If the leakage coefficient xl s If the value is greater than or equal to the leakage threshold, it indicates that there is a leakage problem in the pipeline.

[0128] When a leak is detected in the pipeline at a certain sampling point, the automatic control module activates adjacent sampling points for testing to determine if there are any false positives. Specifically:

[0129] If the leakage coefficient at adjacent sampling points is xl s If the leakage threshold is exceeded, other sampling points near the leak detection sampling point will be activated. If the leakage coefficient at other sampling points is less than the threshold, the process will continue. s If the leakage coefficient at any sampling point is less than the leakage threshold, it is determined that there is a false alarm. s If the value is greater than or equal to the leakage threshold, it is determined that there is no false detection.

[0130] If the leakage coefficient at adjacent sampling points is xl s If the result is greater than or equal to the leakage threshold, it is determined that there is no false detection.

[0131] Example 3: Please refer to Figure 1 As shown in this embodiment, the natural gas pipeline leak detection method based on fiber optic sensing includes the following steps:

[0132] The acquisition unit obtains the number of sampling points set on the pipeline and numbers them. Each sampling point is equipped with a sensor and a fiber optic detection device. Based on the number and number of sampling points on the pipeline, the system controls the interval at which the sampling points are activated for detection (for example, after activating the first sampling point, the second sampling point is not activated, the third sampling point is activated, and so on). When natural gas is being transported through the pipeline, the fiber optic detection device acquires fiber optic data related to pipeline leaks. The sensor is located near the fiber optic detection module to acquire multiple data related to pipeline leaks. After comprehensively analyzing the fiber optic data and multiple data, the system determines whether there is a leak in the pipeline. When a leak is detected at a certain sampling point, the adjacent sampling points are activated for detection (if a sampling point has only one adjacent sampling point, one adjacent sampling point is activated; if a sampling point has two adjacent sampling points, both adjacent sampling points are activated), and the system checks whether there are any false positives.

[0133] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0134] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0135] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A natural gas pipeline leak detection system based on fiber optic sensing, characterized in that: It includes an acquisition module, an initial control module, an optical fiber detection module, a data acquisition module, an analysis module, and an automatic control module; Acquisition module: used to acquire the number of sampling points set on the pipeline and number the multiple sampling points. Each sampling point is equipped with an acquisition module and an optical fiber detection module. Initial control module: Based on the number and numbering information of the sampling points set on the pipeline, it controls the interval at which the sampling points start detection; Fiber optic detection module: When natural gas is transported through a pipeline, it acquires fiber optic data related to pipeline leakage, including the pipeline strain phase index; Acquisition module: Located near the fiber optic detection module, it is used to acquire multiple data related to pipeline leakage, including pipeline pressure fluctuation amplitude and natural gas flow velocity fluctuation amplitude. Analysis module: Determines whether a pipeline leak exists by comprehensively analyzing fiber optic data and multiple other data sources; this includes: calculating the pipeline strain phase index, pipeline pressure fluctuation amplitude, and natural gas flow velocity fluctuation amplitude to obtain the leakage coefficient. Obtain the leakage coefficient Then, the leakage coefficient Compared with the preset leakage threshold, if the leakage coefficient If the leakage coefficient is less than the leakage threshold, it is determined that there is no leakage problem in the pipeline; if the leakage coefficient is less than the leakage threshold, it is determined that there is no leakage problem in the pipeline. A leakage coefficient ≥ a leakage threshold is used to determine if a pipeline is leaking; wherein, the leakage coefficient... The expression is: ； In the formula, The strain phase index of the pipeline. This refers to the amplitude of pipeline pressure fluctuation. This represents the amplitude of natural gas flow velocity fluctuations. , , These are the proportional coefficients for the pipeline strain phase index, pipeline pressure fluctuation amplitude, and natural gas flow velocity fluctuation amplitude, respectively. , , All are greater than 0; Automatic control module: When a leak is detected in the pipeline at a certain sampling point, the adjacent sampling points are activated for detection to determine whether there is any false detection.

2. The natural gas pipeline leak detection system based on fiber optic sensing according to claim 1, characterized in that: When a leak is detected at a sampling point, the automatic control module activates adjacent sampling points for testing to determine if there are any false positives. This process includes the following steps: If the leakage coefficient at adjacent sampling points If the leakage threshold is exceeded, other sampling points near the leak detection point will be activated. If the leakage coefficient at other sampling points is... If the leakage coefficient is less than the leakage threshold, it is determined that there is a false alarm. If the leakage coefficient at any sampling point continues to be activated... If the value is greater than or equal to the leakage threshold, it is determined that there is no false detection. If the leakage coefficient at adjacent sampling points If the result is greater than or equal to the leakage threshold, it is determined that there is no false detection.

3. The natural gas pipeline leak detection system based on fiber optic sensing according to claim 1, characterized in that: The formula for calculating the strain phase index of the pipeline is as follows: ； In the formula, The strain phase index of the pipeline. It is the wavelength of the light from the fiber optic sensor. It is the location of the strain scattering event on the pipeline.

4. The natural gas pipeline leak detection system based on fiber optic sensing according to claim 1, characterized in that: The formula for calculating the amplitude of pipeline pressure fluctuation is: ； In the formula, This refers to the amplitude of pipeline pressure fluctuation. This indicates the actual measured pipe pressure. This indicates the expected or set target pipeline pressure.

5. The natural gas pipeline leak detection system based on fiber optic sensing according to claim 1, characterized in that: The formula for calculating the amplitude of natural gas flow velocity fluctuation is as follows: ； In the formula, This represents the amplitude of natural gas flow velocity fluctuations. This represents the actual measured natural gas flow rate. This indicates the expected or set target natural gas flow rate.

6. A method for detecting leaks in natural gas pipelines based on fiber optic sensing, implemented by the detection system described in any one of claims 1-5, characterized in that: The detection method includes the following steps: S1: The acquisition module acquires the number of sampling points set on the pipeline and numbers the multiple sampling points. Each sampling point is equipped with an acquisition module and an optical fiber detection module. S2: Based on the number and numbering information of the sampling points set on the pipeline, control the interval between sampling points to start detection; S3: When natural gas is being transported through a pipeline, the fiber optic detection module acquires fiber optic data related to pipeline leakage, including the pipeline strain phase index. S4: The acquisition module is located near the fiber optic detection module and is used to acquire multiple data related to pipeline leakage, including pipeline pressure fluctuation amplitude and natural gas flow velocity fluctuation amplitude. S5: After comprehensively analyzing fiber optic data and multiple data sources, determine whether there is a pipeline leak; including: the analysis module comprehensively calculates the pipeline strain phase index, pipeline pressure fluctuation amplitude, and natural gas flow velocity fluctuation amplitude to obtain the leakage coefficient. Obtain the leakage coefficient Then, the leakage coefficient Compared with the preset leakage threshold, if the leakage coefficient If the leakage coefficient is less than the leakage threshold, it is determined that there is no leakage problem in the pipeline; if the leakage coefficient is less than the leakage threshold, it is determined that there is no leakage problem in the pipeline. A leakage coefficient ≥ a leakage threshold is used to determine if a pipeline is leaking; wherein, the leakage coefficient... The expression is: ； In the formula, The strain phase index of the pipeline. This refers to the amplitude of pipeline pressure fluctuation. This represents the amplitude of natural gas flow velocity fluctuations. , , These are the proportional coefficients for the pipeline strain phase index, pipeline pressure fluctuation amplitude, and natural gas flow velocity fluctuation amplitude, respectively. , , All are greater than 0; S6: When a leak is detected at a certain sampling point, start testing at the adjacent sampling points to determine if there is any false detection.

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