Gas leakage detection system based on distributed sensor technology

Abstract

The invention discloses a gas leakage detection system based on a distributed sensor technology, relates to the technical field of gas leakage detection, solves the technical problem that in the prior art, the accuracy of gas leakage detection cannot be reduced due to the fact that pipeline analysis cannot be combined according to an optical fiber vibration sensor technology, and particularly relates to a pipeline position detection and recognition unit. Detecting and identifying the covered pipeline monitored by the distributed sensor, judging whether the gas conveying pipeline has a leakage generation condition in the operation period according to the detection and identification, detecting the position after the leakage generation condition is met, and evaluating the leakage risk; the sensor detection management and control unit is used for detecting the optical fiber vibration sensor and reasonably setting the position; after position setting is completed, the data processing and identifying unit processes and identifies data collected by the optical fiber vibration sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of gas leakage detection, and specifically to a gas leakage detection system based on distributed sensor technology. Background Art

[0002] Distributed fiber optic vibration sensors are based on the photoelastic effect and Rayleigh scattering principle of optical fibers. When the optical fiber is subjected to external vibration, the refractive index and length of the optical fiber will change slightly, resulting in changes in the phase, polarization state and other characteristics of the light transmitted in the optical fiber; by measuring and analyzing these changes, the vibration information along the optical fiber can be detected, and parameters such as the position, frequency and amplitude of the vibration can be determined.

[0003] The existing gas leakage detection adopts a fixed gas leakage detection in a point-like, scattered and local area, and it is impossible to locate the leakage point for pipelines with long distances and high concealment. The detection of micro-leakage at parts such as pipeline welds, valves, flanges and the leakage of gas pipelines in open areas is not sensitive enough, and there are many limitations and hidden blind spots; it is impossible to combine the fiber optic vibration sensor technology with pipeline analysis, reducing the accuracy of gas leakage detection.

[0004] In view of the above technical defects, a solution is now proposed. Summary of the Invention

[0005] The purpose of the present invention is to solve the above-mentioned problems, and to propose a gas leakage detection system based on distributed sensor technology.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A gas leakage detection system based on distributed sensor technology includes a gas leakage detection platform, wherein the gas leakage detection platform is communicatively connected to a pipeline position detection and identification unit, a sensor detection and control unit, and a data processing and identification unit;

[0008] The pipeline position detection and identification unit detects and identifies the pipeline covered by the distributed sensor, judges whether the gas transmission pipeline has the conditions for leakage generation during the operation period according to the detection and identification, and performs position detection and evaluates the leakage risk after the conditions are met;

[0009] The sensor detection and control unit detects the fiber optic vibration sensor and reasonably sets the position;

[0010] After the position setting is completed, the data processing and identification unit processes and identifies the collected data of the fiber optic vibration sensor.

[0011] As a preferred embodiment of the present invention, the process of the pipeline position detection and identification unit is as follows:

[0012] Divide the positions of the gas transmission pipeline according to the splicing process of the gas transmission pipeline and the surface texture of the pipeline, that is, divide the gas transmission pipeline into an overall position and a split position;

[0013] And detect the leakage generation conditions for the overall position and the split position. The leakage generation conditions are expressed as the energy difference between the inside and outside of the pipeline when the gas transmission pipeline conducts gas transmission; at the same time, set physical barriers at the positions of the gas transmission pipeline.

[0014] When taking the entire gas transmission pipeline as the detection object, obtain the average internal pressure during the gas transportation period and the non-operating period inside the gas transmission pipeline. If the average internal pressure is within the set average pressure range, it is determined that the risk of pressure deviation in the gas transmission of the current gas transmission pipeline is low; otherwise, it is inferred that the risk of pressure deviation is high. The gas leakage detection platform adjusts the gas transmission of the gas transmission pipeline, adjusting the transmission volume or the transmission speed.

[0015] As a preferred embodiment of the present invention, when the average internal pressure is within the set range, use the peak value of the average internal pressure as the comparison pressure value, and combine the ambient pressure value of the area where the gas transmission pipeline is located at the moment corresponding to the comparison pressure value. Starting from this moment, continuously compare the comparison pressure value and the ambient pressure value. When comparing: when the comparison pressure value is higher than the ambient pressure value, mark the corresponding moment as the internal strength moment; otherwise, when the comparison pressure value is lower than the ambient pressure value, mark the corresponding moment as the external strength moment.

[0016] As a preferred embodiment of the present invention, according to the statistics of adjacent comparison moments, if the pressure difference corresponding to the internal strength moment or the external strength moment during the continuous detection period exceeds the pressure difference threshold, or the maximum continuous alternation frequency of the internal strength moment and the external strength moment as adjacent moments exceeds the alternation frequency threshold, it is inferred that the leakage generation conditions are met during the operation stage of the gas transmission pipeline; otherwise, if the pressure difference corresponding to the internal strength moment or the external strength moment during the continuous detection period does not exceed the pressure difference threshold, and the maximum continuous alternation frequency of the internal strength moment and the external strength moment as adjacent moments does not exceed the alternation frequency threshold, it is inferred that the leakage generation conditions are not met during the operation stage of the gas transmission pipeline.

[0017] As a preferred embodiment of the present invention, after the leakage generation conditions are met, detect the overall position and the split position;

[0018] During the operation period when leakage generation conditions are met, collect the performance parameters of the physical isolators corresponding to the overall position and the split position of the same type of physical isolator; obtain the floating trend of the performance parameters based on the specific values of the performance parameters at each moment. When the floating trend of the performance parameters shows a downward trend, generate a leakage risk signal and send the leakage risk signal to the gas leakage detection platform. When the floating trend of the performance parameters does not show a downward trend, generate a leakage safety signal and send the leakage safety signal to the gas leakage detection platform.

[0019] As a preferred embodiment of the present invention, in case of leakage risk, if there is a deviation in the downward trend of the performance parameters corresponding to the overall position and the split position, and the downward trend of the overall position is slower than that of the split position, generate a warning protection signal and send the warning protection signal to the gas leakage detection platform; if there is no deviation in the downward trend of the performance parameters corresponding to the overall position and the split position, or the downward trend of the overall position is not slower than that of the split position, generate a synchronous warning protection signal and send the synchronous warning protection signal to the gas leakage detection platform.

[0020] As a preferred embodiment of the present invention, the process of the sensor detection and control unit is as follows:

[0021] Analyze the overall position and the split position, simulate the current environment operation with a fiber optic vibration sensor, and collect the floating span of the fiber optic refractive index corresponding to the pipeline temperature rising stage during gas transportation and the loss span of the fiber optic propagation amount of the fiber optic vibration sensor corresponding to the internal deformation of the pipeline.

[0022] If both the floating span of the fiber optic refractive index corresponding to the pipeline temperature rising stage during gas transportation and the loss span of the fiber optic propagation amount of the fiber optic vibration sensor corresponding to the internal deformation of the pipeline are within the corresponding span threshold ranges, it is inferred that the current simulated operation position is suitable for installing a sensor.

[0023] If both the floating span of the fiber optic refractive index corresponding to the pipeline temperature rising stage during gas transportation and the loss span of the fiber optic propagation amount of the fiber optic vibration sensor corresponding to the internal deformation of the pipeline are not within the corresponding span threshold ranges, it is inferred that the current simulated operation position is not suitable for installing a sensor.

[0024] As a preferred embodiment of the present invention, mark the positions with leakage generation conditions as leakage risk positions, and according to the distribution density of the leakage risk positions corresponding to the gas transportation pipeline;

[0025] If the distribution density is higher than the set density threshold, the installation method is as follows: set up the sensor core processor and place it at the center position, and centrally install the sensors with the center as the origin. The processor will centrally send the collected data of the sensors. If the distribution density is lower than the set density threshold, the installation method is as follows: use a single sensor as the main body to cover the corresponding position, and distributively send the real-time collected data.

[0026] As a preferred embodiment of the present invention, the process of the data processing and recognition unit is as follows:

[0027] Detect each position in the gas transmission pipeline through the fiber optic vibration sensor, and analyze the phase change and polarization state change by collecting data. During the operation of the gas transmission pipeline, collect the phase of light transmitted in the optical fiber when external vibration is detected, and at the same time collect the change in the distribution state of light as an electromagnetic wave at each position of the current gas transmission pipeline.

[0028] As a preferred embodiment of the present invention, if there is a fluctuation in the phase of light transmitted in the optical fiber when external vibration occurs, or a change in the distribution state of light as an electromagnetic wave occurs at each position of the current gas transmission pipeline, it is inferred that gas leakage has occurred at the current position, and the current position is sent to the gas leakage detection platform. If there is no fluctuation in the phase of light transmitted in the optical fiber when external vibration occurs, and no change in the distribution state of light as an electromagnetic wave occurs at each position of the current gas transmission pipeline, it is inferred that no gas leakage has occurred at the current position, and continuous monitoring is carried out.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] 1. In the present invention, the pipeline monitored and covered by the distributed sensors is detected and identified, and the risk of gas leakage points is estimated through pipeline detection and identification. At the same time, based on the risk estimation, it can be used as an effective basis to set the sensor layout specifically, ensuring that the fitting degree of the distributed sensor points can more effectively adapt to the current pipeline gas transmission. At the same time, the pipeline position detection can also give early warnings in a timely manner, reducing the risk of gas leakage in the pipeline and improving the efficiency and feasibility of gas transmission.

[0031] 2. In the present invention, the fiber optic vibration sensor is detected and the position is set reasonably to facilitate the detection of the gas transmission pipeline, and the detection data is processed and synchronized with various types of warning signals received; such as synchronizing the warning protection signal to perform synchronous monitoring and warning control on various types of positions, and for the warning protection signal, targeted monitoring and warning are carried out on the split positions; for the leakage risk signal, leakage detection and repair are carried out in cooperation with the sensor;

[0032] Process and identify the collected data of the fiber optic vibration sensor, infer the current degree of gas leakage through data processing, and real-time locate the leakage position according to the change of the leakage degree, so as to improve the accurate control based on the leakage position in real time during leakage repair and avoid the decrease of repair efficiency caused by leakage deviation during the leakage reduction process. Brief Description of the Drawings

[0033] For the convenience of those skilled in the art to understand, the present invention will be further described below in conjunction with the accompanying drawings.

[0034] Figure 1 It is the system principle block diagram of the whole of the present invention;

[0035] Figure 2 It is the method flow chart of the pipeline position detection and identification unit in the present invention. Detailed Embodiments

[0036] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0037] Referring to "embodiments" herein means that the specific features, structures or characteristics described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The phrase appears in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0038] Please refer to Figure 1 As shown, a gas leakage detection system based on distributed sensor technology includes a gas leakage detection platform, wherein the gas leakage detection platform is communicatively connected to a pipeline position detection and identification unit, a sensor detection and control unit, and a data processing and identification unit; it should be noted that the thresholds involved in this application are all parameters set by those skilled in the art through historical operation processes combined with human experience during actual operation for real-time parameter detection;

[0039] The gas leakage detection platform generates a pipeline position detection and identification signal and sends the pipeline position detection and identification signal to the pipeline position detection and identification unit;

[0040] The pipeline position detection and recognition unit is used to receive pipeline position detection and recognition signals. After receiving the signals, it detects and recognizes the monitored and covered pipelines of the distributed sensors. Through pipeline detection and recognition, it estimates the risks of gas leakage points. At the same time, based on the risk estimation, it can be used as an effective basis to make targeted settings for sensor layout, ensuring that the fitting degree of the distributed sensor points can more effectively adapt to the current pipeline gas transportation. At the same time, pipeline position detection can also give early warnings in a timely manner, reducing the risk of gas leakage in the pipeline and improving the efficiency and feasibility of gas transportation;

[0041] Please refer to Figure 2 As shown, according to the splicing process of the gas transportation pipeline and the surface texture of the pipeline, the position of the gas transportation pipeline is divided, that is, the gas transportation pipeline is divided into an overall position and a split position. The overall position means that the surface of the gas transportation pipeline is made of integral material without cutting and welding; the split position means that the surface of the gas transportation pipeline is not made of integral material and there is cutting, splicing or welding, etc.;

[0042] And the leakage generation conditions of the overall position and the split position are detected. The leakage generation conditions refer to the energy difference inside and outside the pipeline during gas transportation in the gas transportation pipeline, specifically the temperature difference, pressure difference and velocity difference; at the same time, physical isolators such as heat insulation layers are set at the position of the gas transportation pipeline;

[0043] When taking the entire gas transportation pipeline as the detection object, the average internal pressure during the gas transportation period and the non-operating period in the gas transportation pipeline is obtained. If the average internal pressure is within the set average pressure range, it is judged that the risk of pressure deviation in the current gas transportation pipeline is low; otherwise, it is inferred that the pressure deviation risk is high. The gas leakage detection platform adjusts the gas transportation of the gas transportation pipeline, adjusting the transportation volume or transportation speed;

[0044] Subsequently, when the average internal pressure is within the set range, the peak value of the average internal pressure is used as the comparison pressure value, and combined with the environmental pressure value in the area where the gas transportation pipeline is located at the moment corresponding to the comparison pressure value, starting from this moment, the comparison pressure value and the environmental pressure value are continuously compared. When comparing: when the comparison pressure value is higher than the environmental pressure value, the corresponding moment is marked as the internal strength moment; otherwise, when the comparison pressure value is lower than the environmental pressure value, the corresponding moment is marked as the external strength moment;

[0045] According to the adjacent comparison time statistics, if the pressure difference corresponding to the internal strong moment or the external strong moment during the continuous detection period exceeds the pressure difference threshold, or the maximum value of the continuous alternating frequency of the internal strong moment and the external strong moment as adjacent moments exceeds the alternating frequency threshold, it is inferred that the gas transmission pipeline operation stage during the continuous detection period has the conditions for leakage generation; conversely, if the pressure difference corresponding to the internal strong moment or the external strong moment during the continuous detection period does not exceed the pressure difference threshold, and the maximum value of the continuous alternating frequency of the internal strong moment and the external strong moment as adjacent moments does not exceed the alternating frequency threshold, it is inferred that the gas transmission pipeline operation stage during the continuous detection period does not have the conditions for leakage generation;

[0046] After the conditions for leakage generation are met, detect the overall position and the split position;

[0047] During the operation period when the conditions for leakage generation are met, collect the performance parameters of the physical isolators corresponding to the overall position and the split position with the same type of physical isolator. For example, for the thermal insulation layer, parameters such as the internal temperature floating reduction value are collected; according to the specific values of the performance parameters of the physical isolators at each moment, obtain the floating trend of the performance parameters. When the floating trend of the performance parameters shows a downward trend, it is inferred that the probability of leakage corresponding to the overall position and the split position is high, generate a leakage risk signal and send the leakage risk signal to the gas leakage detection platform. When the floating trend of the performance parameters does not show a downward trend, it is inferred that the probability of leakage corresponding to the overall position and the split position is low, generate a leakage safety signal and send the leakage safety signal to the gas leakage detection platform;

[0048] In case of leakage risk, if there is a deviation in the downward trend of the performance parameters corresponding to the overall position and the split position, and the downward trend of the overall position is slower than that of the split position, it is inferred that the leakage degree of the split position is higher than that of the overall position, generate a warning protection signal for the split position and send the warning protection signal for the split position to the gas leakage detection platform;

[0049] If there is no deviation in the downward trend of the performance parameters corresponding to the overall position and the split position, or the downward trend of the overall position is not slower than that of the split position, it is inferred that the deviation of the leakage degree between the split position and the overall position is within the set range, generate a synchronous warning protection signal and send the synchronous warning protection signal to the gas leakage detection platform;

[0050] After the gas leakage detection platform receives various types of warning signals, it generates sensor detection control signals and sends the sensor detection control signals to the sensor detection control unit to detect the fiber optic vibration sensor and reasonably set its position for detecting the gas transmission pipeline, and synchronously process according to the detection data processing combined with the received various types of warning signals; if a synchronous warning protection signal is received, it performs synchronous monitoring and warning control on various types of positions, and for the warning protection signal, it performs targeted monitoring and warning on the split positions; for the leakage risk signal, it cooperates with the sensor to detect and repair the leakage.

[0051] The sensor detection control unit is used to detect and analyze the surrounding environment of the gas transmission pipeline after receiving the sensor detection control signal, so as to infer whether the surrounding environment is suitable for installing the fiber optic vibration sensor for detection, improve the detection accuracy of the fiber optic vibration sensor, ensure that the real-time monitoring can meet the requirements of the current position, and also ensure that the data at each position is not lost, so as to improve the accuracy of gas transmission pipeline leakage detection.

[0052] Analyze the overall position and the split position, and simulate the current environment operation with the fiber optic vibration sensor, and collect the floating span of the fiber refractive index corresponding to the pipeline temperature rise stage during gas transmission and the loss span of the fiber propagation amount of the fiber optic vibration sensor corresponding to the internal deformation of the pipeline. The loss span of the fiber propagation amount can be monitored by the fiber for a fixed area. If the test accuracy deviates during the same fiber test duration, it indicates that the loss during the propagation process increases; the simulated operation means inferring whether the actual detection efficiency can be achieved by combining the current environmental parameters, the influence parameters generated by pipeline transmission, and the performance parameters of the sensor itself.

[0053] If both the floating span of the fiber refractive index corresponding to the pipeline temperature rise stage during gas transmission and the loss span of the fiber propagation amount of the fiber optic vibration sensor corresponding to the internal deformation of the pipeline are within the corresponding span threshold ranges, it is inferred that the current simulated operation position is suitable for setting the sensor.

[0054] If both the floating span of the fiber refractive index corresponding to the pipeline temperature rise stage during gas transmission and the loss span of the fiber propagation amount of the fiber optic vibration sensor corresponding to the internal deformation of the pipeline are not within the corresponding span threshold ranges, it is inferred that the current simulated operation position is not suitable for setting the sensor.

[0055] After obtaining the positions suitable for setting the sensor, mark the positions with the conditions for leakage generation as leakage risk positions, and according to the distribution density of the leakage risk positions corresponding to the gas transmission pipeline, where the distribution density is expressed as the proportion of the number of leakage risk positions in the current regional position.

[0056] Conduct a leakage risk location distribution density analysis on the suitable positions for installing sensors. If the distribution density is higher than the set density threshold, install sensors at the currently suitable positions for sensor installation, and the installation method is as follows: Set up a sensor core processor and place it at the center of the position. Concentrate the installation of sensors with the center as the origin, and the processor will centrally send the collected data of the sensors. It should be noted that when the density is too high, the floating buffer time of each position is short and the floating deviation of the pipeline transportation parameters is small. Therefore, synchronous transmission can more real-time reflect the current leakage situation;

[0057] If the distribution density is lower than the set density threshold, install sensors at the currently suitable positions for sensor installation, and the installation method is as follows: Use a single sensor as the main body and target to cover the corresponding positions, and distribute the real-time collected data. This can avoid the inconsistent update cycles of the data collected by the sensors. Synchronous transmission will make the data at each position inconsistent and unable to obtain the leakage situation in a timely and effective manner;

[0058] After completing the sensor detection and setting the positions, the gas leakage detection platform generates a data processing and recognition signal and sends the data processing and recognition signal to the data processing and recognition unit;

[0059] After receiving the data processing and recognition signal, the data processing and recognition unit processes and recognizes the collected data of the fiber optic vibration sensor, infers the current degree of gas leakage through data processing, and real-time locates the leakage position according to the change of the leakage degree, so as to improve the accurate control based on the leakage position during leakage repair and avoid the decrease of repair efficiency caused by leakage deviation during the leakage reduction process;

[0060] Detect each position in the gas transmission pipeline through the fiber optic vibration sensor, and conduct phase change analysis and polarization state change analysis through the collected data;

[0061] During the operation of the gas transmission pipeline, collect the phase of light transmitted in the optical fiber when external vibration is detected, and at the same time collect the change of the distribution state of light as an electromagnetic wave at each position of the current gas transmission pipeline;

[0062] If there is a floating in the phase of light transmitted in the optical fiber when external vibration is detected, or a change occurs in the distribution state of light as an electromagnetic wave at each position of the current gas transmission pipeline, it is inferred that gas leakage occurs at the current position, and the current position is sent to the gas leakage detection platform. After receiving the real-time gas leakage position, the gas leakage detection platform conducts leakage repair and simultaneously conducts synchronous monitoring on the same type of positions or positions with the same risk type;

[0063] It should be noted that the phase fluctuation can be calculated by measuring the number of moving interference fringes or their changes, and the change amount of the phase can be obtained; the change in the distribution state of the optical electromagnetic wave is represented as the change in the distribution waveform. In the prior art, a polarization beam splitter is used to split the incident light into two beams according to different polarization directions, and then the light intensities of the two beams are measured by photodetectors respectively.

[0064] If there is no phase fluctuation in the light transmitted in the optical fiber during external vibration and no change occurs in the distribution state of the light as an electromagnetic wave at each position of the current gas transmission pipeline, it is inferred that there is no gas leakage at the current position, and continuous monitoring is carried out.

[0065] When the present invention is in use, the pipeline position detection and recognition unit detects and recognizes the pipeline covered by the distributed sensor, determines whether the gas transmission pipeline has the conditions for leakage during the operation period according to the detection and recognition, and performs position detection and evaluates the leakage risk after the conditions are met; the sensor detection and control unit detects the fiber optic vibration sensor and reasonably sets the position; after the position setting is completed, the data processing and recognition unit processes and recognizes the collected data of the fiber optic vibration sensor.

[0066] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A gas leakage detection system based on distributed sensor technology, characterized in that It includes a gas leakage detection platform, which is communicatively connected to a pipeline position detection and identification unit, a sensor detection and control unit, and a data processing and identification unit; The pipeline position detection and identification unit detects and identifies the pipelines covered by the distributed sensors, judges whether the gas transmission pipeline has the conditions for leakage generation during the operation period according to the detection and identification, and performs position detection and evaluates the leakage risk after the conditions are met; The sensor detection and control unit detects the fiber optic vibration sensor and reasonably sets its position; After the position setting is completed, the data processing and identification unit processes and identifies the collected data of the fiber optic vibration sensor.

2. The gas leakage detection system based on distributed sensor technology according to claim 1, wherein The process of the pipeline position detection and identification unit is as follows: According to the splicing process of the gas transmission pipeline and the surface texture of the pipeline, the position of the gas transmission pipeline is divided, that is, the gas transmission pipeline is divided into an overall position and a split position; And the leakage generation conditions of the overall position and the split position are detected. The leakage generation conditions are expressed as the energy difference inside and outside the pipeline when the gas transmission pipeline conducts gas transmission; at the same time, physical isolation objects are set at the position of the gas transmission pipeline; When the entire gas transmission pipeline is used as the detection object, the average internal pressure during the gas transportation period and the non-operation period of the gas transmission pipeline is obtained. If the average internal pressure is within the set average pressure range, it is judged that the risk of pressure deviation generated by the gas transmission of the current gas transmission pipeline is low. Otherwise, it is inferred that the pressure deviation risk is high, and the gas leakage detection platform adjusts the gas transmission of the gas transmission pipeline, adjusting the transmission volume or the transmission speed.

3. The gas leakage detection system based on distributed sensor technology according to claim 2, characterized in that When the average internal pressure is within the set range, the peak value of the average internal pressure is used as the comparison pressure value, and combined with the ambient pressure value of the area where the gas transmission pipeline is located at the moment corresponding to the comparison pressure value, starting from this moment, the comparison pressure value and the ambient pressure value are continuously compared. During the comparison: when the comparison pressure value is higher than the ambient pressure value, the corresponding moment is marked as the internal strength moment; otherwise, when the comparison pressure value is lower than the ambient pressure value, the corresponding moment is marked as the external strength moment.

4. The gas leakage detection system based on distributed sensor technology according to claim 3, characterized in that, According to the statistics of adjacent comparison moments, if the pressure difference corresponding to the internal strength moment or the external strength moment exceeds the pressure difference threshold during the continuous detection period, or the maximum continuous alternation frequency of the internal strength moment and the external strength moment as adjacent moments exceeds the alternation frequency threshold, it is inferred that the gas transmission pipeline operation stage has the conditions for leakage generation during the continuous detection period; otherwise, if the pressure difference corresponding to the internal strength moment or the external strength moment does not exceed the pressure difference threshold during the continuous detection period, and the maximum continuous alternation frequency of the internal strength moment and the external strength moment as adjacent moments does not exceed the alternation frequency threshold, it is inferred that the gas transmission pipeline operation stage does not have the conditions for leakage generation during the continuous detection period.

5. The gas leakage detection system based on distributed sensor technology according to claim 4, characterized in that, After the conditions for leakage generation are met, the overall position and the split position are detected; During the operation period when leakage conditions exist, collect the performance parameters of the physical isolators corresponding to the overall position and the split position of the same type of physical isolator; obtain the floating trend of the performance parameters according to the specific values of the performance parameters at each moment. When the floating trend of the performance parameters shows a downward trend, a leakage risk signal is generated and sent to the gas leakage detection platform. When the floating trend of the performance parameters does not show a downward trend, a leakage safety signal is generated and sent to the gas leakage detection platform.

6. The gas leakage detection system based on distributed sensor technology according to claim 5, characterized in that, In case of leakage risk, if there is a deviation in the downward trend of the performance parameters corresponding to the overall position and the split position, and the downward trend of the overall position is slower than that of the split position, a warning protection signal is generated and sent to the gas leakage detection platform; if there is no deviation in the downward trend of the performance parameters corresponding to the overall position and the split position, or the downward trend of the overall position is not slower than that of the split position, a synchronous warning protection signal is generated and sent to the gas leakage detection platform.

7. The gas leakage detection system based on distributed sensor technology according to claim 1, characterized in that, The process of the sensor detection and control unit is as follows: Analyze the overall position and the split position, simulate the current environment with an optical fiber vibration sensor, and collect the floating span of the optical fiber refractive index corresponding to the pipeline temperature rise stage during gas transportation and the loss span of the optical fiber propagation amount of the optical fiber vibration sensor corresponding to the internal deformation of the pipeline. If both the floating span of the optical fiber refractive index corresponding to the pipeline temperature rise stage during gas transportation and the loss span of the optical fiber propagation amount of the optical fiber vibration sensor corresponding to the internal deformation of the pipeline are within the corresponding span threshold ranges, it is inferred that the current simulated operation position is suitable for installing sensors. If both the floating span of the optical fiber refractive index corresponding to the pipeline temperature rise stage during gas transportation and the loss span of the optical fiber propagation amount of the optical fiber vibration sensor corresponding to the internal deformation of the pipeline are not within the corresponding span threshold ranges, it is inferred that the current simulated operation position is not suitable for installing sensors.

8. The gas leakage detection system based on distributed sensor technology according to claim 7, characterized in that Mark the positions with leakage generation conditions as leakage risk positions, and according to the distribution density of the gas transmission pipeline corresponding to the leakage risk positions; If the distribution density is higher than the set density threshold, the installation method is: set up a sensor core processor and place it at the center of the position, and centrally install the sensors with the center as the origin, and the processor will centrally send the collected data of the sensors; if the distribution density is lower than the set density threshold, the installation method is: use a single sensor as the main body and cover the corresponding position, and distribute and send the real-time collected data.

9. The gas leakage detection system based on distributed sensor technology according to claim 1, characterized in that, The process of the data processing and recognition unit is as follows: Detect each position in the gas transmission pipeline through an optical fiber vibration sensor, and analyze the phase change and polarization state change through the collected data; during the operation of the gas transmission pipeline, collect the phase of light transmitted in the optical fiber when external vibration is detected, and at the same time collect the change in the distribution state of light as an electromagnetic wave at each position of the current gas transmission pipeline.

10. The gas leakage detection system based on distributed sensor technology according to claim 9, characterized in that, If there is a fluctuation in the phase of light transmission in the optical fiber during external vibration, or it is caused by a change in the distribution state of light as an electromagnetic wave at each position of the current gas transmission pipeline, it is inferred that gas leakage occurs at the current position, and the current position is sent to the gas leakage detection platform; if there is no fluctuation in the phase of light transmission in the optical fiber during external vibration, and there is no change in the distribution state of light as an electromagnetic wave at each position of the current gas transmission pipeline, it is inferred that no gas leakage occurs at the current position, and continuous monitoring is carried out.

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