Chemical pipeline lateral deviation detection method based on Brillouin stress

Abstract

The invention discloses a chemical pipeline transverse deviation detection method and system based on Brillouin stress, and belongs to the technical field of chemical pipeline safety monitoring, a Brillouin stress sensing network is constructed through arrangement of a sensing optical cable and a stress sensing unit, a sensing structure support is provided for deviation monitoring of a chemical pipeline, and the safety of the chemical pipeline is improved. Scene adaptation of the sensing unit and the chemical pipeline is achieved, the Brillouin detection device is used for conducting multi-stage processing and interference quantity screening on reverse Brillouin scattered light signals of all stress measurement point positions, accurate Brillouin stress frequency shift variation data of all the stress measurement point positions are calculated, and the accuracy of the Brillouin stress frequency shift variation data is improved. On the basis of the strain key parameters and an accurate geometric constraint model, conversion and decomposition calculation from the frequency shift variable quantity to the transverse offset of the pipeline are achieved, and the accurate transverse offset of the pipeline is obtained; in addition, real-time detection is carried out through the sensing optical cable, all-time, low-delay and short-interval unmanned monitoring can be realized, and safety monitoring blind areas are avoided.

Description

Technical Field

[0001] This invention belongs to the field of chemical pipeline safety monitoring technology, specifically relating to a method for detecting lateral displacement of chemical pipelines based on Brillouin stress. Background Technology

[0002] Chemical pipelines, as the "lifeline" of process industries, bear the critical responsibility of transporting high-temperature, high-pressure, flammable, explosive, and highly corrosive media. Their operational safety directly impacts production continuity, the safety of personnel and property, and the ecological environment. During long-term operation, pipelines are highly susceptible to lateral displacement due to various factors, including internal media flow impacts (such as pump and valve start-up and shutdown), thermal stress caused by drastic temperature changes, external loads, and settlement or fatigue of supporting structures. This displacement primarily manifests as horizontal collisions and torsion, as well as vertical settlement or bulging. Even minor, undetected displacements can accumulate stress, eventually leading to flange leaks, weld cracks, supporting structure failure, and even catastrophic media leaks, fires, explosions, and poisoning accidents, with consequences far exceeding those of ordinary municipal or building pipelines.

[0003] In existing chemical pipeline monitoring technologies, the monitoring of lateral deviations in chemical pipelines mainly relies on regular manual inspections. During inspections, personnel need to use equipment such as laser rangefinders and total stations to measure the deviation of pre-marked points on the chemical pipeline within a safe window. This monitoring method requires inspection personnel to frequently enter areas with toxic, corrosive, and high-temperature risks, posing extremely high personal safety risks. Furthermore, manual inspections are not only subject to significant errors due to external factors such as experience, but also fail to capture instantaneous or dynamic deviations caused by pump start-up and shutdown, pressure fluctuations, etc., due to the long inspection intervals. This creates a huge blind spot in safety monitoring.

[0004] As mentioned above, how to provide a Brillouin stress-based lateral displacement detection method for chemical pipelines that can adapt to the working environment of chemical pipelines and achieve high-precision real-time measurement has become an urgent research topic in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for detecting lateral displacement of chemical pipelines based on Brillouin stress, in order to solve the above-mentioned problems existing in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for detecting lateral displacement of a chemical pipeline based on Brillouin stress, comprising: laying a tensioned sensing optical cable along the direction of the chemical pipeline to be monitored; connecting a Brillouin detection device to one end of the sensing optical cable; installing stress sensing units at each key support node of the chemical pipeline to be monitored; and connecting the stress sensing units in series through the sensing optical cable to form a Brillouin stress sensing network. The method is implemented based on the Brillouin stress sensing network, including: The Brillouin detection device emits a narrow pulse light signal to the sensing optical cable and obtains a reverse Brillouin scattered light signal from the sensing optical cable. The reverse Brillouin scattered light signal is photoelectrically converted and processed to obtain Brillouin scattering data for each stress measurement point. Based on the Brillouin scattering data for each stress measurement point, a Brillouin gain spectrum for each stress measurement point is generated. Each stress measurement point is the center point of the connection between each stress sensing unit and the sensing optical cable. Based on the Brillouin gain spectrum of each stress measurement point, peak values ​​are calculated for each stress measurement point to obtain the original Brillouin frequency shift change data corresponding to each stress measurement point. Interference is filtered out from the original Brillouin frequency shift change data of each stress measurement point using the dual-fiber temperature compensation method and digital filtering algorithm to obtain the Brillouin stress frequency shift change data of each stress measurement point. The strain key parameters and geometric constraint models of each stress sensing unit are obtained. Based on the Brillouin stress frequency shift change data and the strain key parameters of each stress sensing unit at each stress measurement point, the strain value of the sensing optical cable at each stress measurement point is calculated. Through the geometric constraint model of each stress sensing unit, the strain value of the sensing optical cable at each stress measurement point is converted into the pipeline plane displacement of the chemical pipeline to be monitored at each stress measurement point. The pipeline plane displacement at each stress measurement point is decomposed to obtain the lateral offset of the chemical pipeline to be monitored at each stress measurement point. The lateral offset of the monitored chemical pipeline at each stress measurement point is visualized and analyzed for pipeline safety. The analysis results are obtained, and corresponding prompts are generated and issued based on the analysis results.

[0007] In one possible design, the Brillouin detection device includes a narrow-pulse laser source, an optical signal processing unit, an electrical signal processing unit, and a data computing terminal. One end of the sensing optical cable is connected to the narrow-pulse laser source and the optical signal processing unit, and the other end of the sensing optical cable is provided with an anti-reflection fiber optic terminator. The output end of the optical signal processing unit is electrically connected to the input end of the electrical signal processing unit, and the output end of the electrical signal processing unit is electrically connected to the data computing terminal. The narrow-pulse laser source is used to emit nanosecond-level optical pulse signals. The key support nodes of the chemical pipeline to be monitored include key support points and corresponding supports on the chemical pipeline. Each stress sensing unit includes a wedge, a fixed bracket, a spring, and an optical cable clamp. The wedge is rigidly fixed to each key support point of the chemical pipeline to be monitored. The fixed bracket is fixedly installed on each support of the chemical pipeline to be monitored. The fixed end of the spring is fixedly connected to the fixed bracket. The other end of the spring is rigidly connected to the optical cable clamp. The clamping end of the optical cable clamp is used to clamp the sensing optical cable. The inclined surface of the wedge in each stress sensing unit contacts the open end of the corresponding spring according to a preset pressure. The clamping direction of each optical cable clamp is perpendicular to the axis of the chemical pipeline to be monitored.

[0008] In one possible design, a narrow-pulse optical signal is emitted to the sensing optical cable via the Brillouin detection device, and a reverse Brillouin scattered optical signal is acquired from the sensing optical cable. The reverse Brillouin scattered optical signal is then subjected to photoelectric conversion and signal processing to obtain Brillouin scattering data for each stress measurement point. Based on the Brillouin scattering data for each stress measurement point, a Brillouin gain spectrum for each stress measurement point is generated, including: A narrow pulse light signal is emitted to the sensing optical cable through the narrow pulse laser source in the Brillouin detection device, and the reverse Brillouin scattered light signal is obtained from the sensing optical cable through the optical signal processing unit in the Brillouin detection device. The optical signal processing unit performs photoelectric conversion on the reverse Brillouin scattering optical signal to generate the original Brillouin scattering radio frequency electrical signal, and outputs the original Brillouin scattering radio frequency electrical signal to the electrical signal processing unit. The original Brillouin scattering radio frequency signal is amplified and bandpass filtered by the electrical signal processing unit to obtain a Brillouin scattering radio frequency signal. The Brillouin scattering radio frequency signal is then converted from analog to digital by the electrical signal processing unit to obtain global Brillouin scattering data. The global Brillouin scattering data is then output to the data computing terminal. The data computing terminal acquires preset stress measurement point information, maps the global Brillouin scattering data according to the stress measurement point information, obtains Brillouin scattering data for each stress measurement point, and performs short-time Fourier transform analysis on the Brillouin scattering data for each stress measurement point through the data computing terminal to obtain the Brillouin gain spectrum for each stress measurement point.

[0009] In one possible design, before acquiring the preset stress measurement point information through the data calculation terminal, the following is also included: After the Brillouin stress sensing network is deployed, the data computing terminal obtains the emission time of each narrow pulse light signal emitted by the narrow pulse laser source and the reception time of each reverse Brillouin scattered light signal received by the optical signal processing unit. Based on the emission time of each narrow pulse optical signal and the reception time of each reverse Brillouin scattering optical signal, the propagation time of multiple optical signals is calculated. Based on the principle of optical time-domain reflection, the propagation distance of each optical signal is calculated using the propagation time of each optical signal. The propagation distance of each optical signal is then used as the distance of multiple sensing optical cables. In the Brillouin stress sensing network, the numbering information of each stress sensing unit is obtained, and the numbering information of each stress sensing unit is matched one-to-one with the distance of each sensing optical cable to form multiple stress measurement points. The distance of each sensing optical cable is added to each stress measurement point to obtain stress measurement point information. The stress measurement point information is stored in the data computing terminal.

[0010] In one possible design, based on the Brillouin gain spectrum of each stress measurement point, peak value calculation is performed on each stress measurement point to obtain the original Brillouin frequency shift change data corresponding to each stress measurement point, including: The peak value of the Brillouin gain spectrum at each stress measurement point is calculated using the data calculation terminal to extract the peak frequency of the Brillouin gain spectrum at each stress measurement point. The peak value calculation includes Lorentz curve fitting or Voigt curve fitting. Obtain the preset reference calibration frequency for each stress measurement point, calculate the corresponding difference between the peak frequency of the Brillouin gain spectrum of each stress measurement point and the reference calibration frequency of each stress measurement point, and obtain the original Brillouin frequency shift change corresponding to each stress measurement point.

[0011] In one possible design, after the Brillouin stress sensing network is formed, a reference optical cable identical to the sensing optical cable is laid in parallel with the sensing optical cable according to the Brillouin stress sensing network, and the reference optical cable does not mechanically contact each of the stress sensing units.

[0012] In one possible design, interference is filtered out from the original Brillouin frequency shift variation data at each stress measurement point using a dual-fiber temperature compensation method and a digital filtering algorithm, resulting in Brillouin stress frequency shift variation data for each stress measurement point, including: The narrow pulse laser source synchronously emits a narrow pulse optical signal to the reference optical cable, and the optical signal processing unit obtains the reverse Brillouin scattering reference signal from the reference optical cable. The optical signal processing unit and the electrical signal processing unit perform photoelectric conversion and signal processing on the reverse Brillouin scattering light reference signal to obtain global Brillouin scattering reference data. The data computing terminal then calculates the Brillouin scattering reference data for each stress measurement point based on the global Brillouin scattering reference data, thereby generating a reference Brillouin gain spectrum for each stress measurement point. Peak values ​​are calculated for the reference Brillouin gain spectra at each stress measurement point to obtain reference Brillouin frequency shift data for each reference Brillouin gain spectrum. The reference Brillouin frequency shift data for each reference Brillouin gain spectrum is used as the temperature interference at each stress measurement point. Based on the dual-fiber temperature compensation method, the original Brillouin frequency shift change data of each stress measurement point are subtracted by the temperature interference term of each stress measurement point to complete the temperature interference filtering and obtain the pre-Brillouin stress frequency shift change data of each stress measurement point. Based on a digital filtering algorithm, electromagnetic interference is filtered out from the pre-Brillouin stress frequency shift change data of each stress measurement point to obtain the Brillouin stress frequency shift change data of each stress measurement point. The digital filtering algorithm includes a sliding filter algorithm or a wavelet denoising algorithm.

[0013] In one possible design, the strain key parameters and geometric constraint models of each stress sensing unit are obtained. Based on the Brillouin stress frequency shift variation data at each stress measurement point and the strain key parameters of each stress sensing unit, the strain value of the sensing optical cable at each stress measurement point is calculated, including: The data calculation terminal obtains the strain key parameters of each stress sensing unit, wherein the strain key parameters include the calibration strain coefficient and the tension reference length of the sensing optical cable, and the tension reference length of the sensing optical cable is used to represent the effective sensing section length of the sensing optical cable between adjacent stress measurement points. Based on the calibrated strain coefficient of each stress sensing unit, the strain value of the sensing optical cable corresponding to each stress measurement point is calculated using the following formula (1): (1) in, This indicates the strain value of the sensing optical cable at the stress measurement point. This represents the Brillouin stress frequency shift variation data at the stress measurement point. This represents the calibrated strain coefficient of the stress sensing unit.

[0014] In one possible design, using the geometric constraint model of each stress sensing unit, the strain value of the sensing optical cable at each stress measurement point is converted into the pipe plane displacement of the chemical pipeline to be monitored at each stress measurement point. The pipe plane displacement at each stress measurement point is then decomposed to obtain the lateral offset of the chemical pipeline to be monitored at each stress measurement point, including: Based on the tension reference length of the sensing optical cable, the spring body deformation of the spring body corresponding to each stress measurement point is calculated using the following formula (2): (2) in, This represents the spring body deformation corresponding to the stress measurement point. This indicates the tension reference length of the sensing optical cable; The geometric constraint model of each stress sensing unit is obtained through the data computing terminal, wherein the geometric constraint model includes wedge size parameters, wedge tilt angle parameters and wedge inclined surface displacement transfer ratio; Based on the displacement transmission ratio of the wedge-shaped inclined surface, the spring body deformation of each stress measurement point is decomposed by the following formula (3) to be converted into the pipe plane displacement corresponding to each stress measurement point. (3) in, This indicates the amount of planar displacement of the pipe at the stress measurement point. This indicates the displacement transfer ratio of the wedge-shaped inclined surface; Based on the wedge inclination angle parameter, the pipe plane displacement at each stress measurement point is decomposed into the pipe lateral offset corresponding to each stress measurement point by the following formula (4); (4) in, This indicates the lateral offset of the pipe at the stress measurement point. This represents the inclination angle parameter of the wedge.

[0015] In one possible design, the lateral offset of the monitored chemical pipeline at each stress measurement point is visualized and analyzed for pipeline safety. The analysis results are then used to generate and issue corresponding alerts, including: The data computing terminal integrates the lateral offsets of various pipelines obtained at different sampling times to draw a curve showing the relationship between the lateral offset of the pipeline and time, which serves as a real-time trend chart for the pipeline safety analysis of the chemical pipeline to be monitored. Through the data computing terminal, the real-time result display signal is generated for the lateral displacement of the pipeline at each stress measurement point and the real-time analysis trend of the pipeline safety of the chemical pipeline under monitoring. The real-time result display signal is then sent to the display screen to visualize the lateral displacement of the pipeline at each stress measurement point and the real-time analysis trend of the pipeline safety of the chemical pipeline under monitoring. The preset pipeline lateral offset warning threshold is obtained through the data calculation terminal. Based on the pipeline lateral offset warning threshold, the pipeline safety analysis is performed on the pipeline lateral offset at each stress measurement point to obtain the analysis results. If the analysis result indicates that the lateral offset of the pipeline at the stress measurement point does not exceed the lateral offset warning threshold, then a pipeline safety warning message is generated and sent to the safety management server. If the analysis result indicates that the lateral offset of the pipeline at the stress measurement point exceeds the lateral offset warning threshold, a pipeline anomaly alert is generated and sent to the safety management server.

[0016] Secondly, the present invention provides a lateral displacement detection system for chemical pipelines based on Brillouin stress. The system is installed in a safety management server, which is communicatively connected to the Brillouin detection device. The system includes: The detection start unit is used to send a detection start signal to the Brillouin detection device, emit a narrow pulse light signal to the sensing optical cable, and obtain a reverse Brillouin scattering light signal from the sensing optical cable. The reverse Brillouin scattering light signal is then photoelectrically converted and processed to obtain Brillouin scattering data at each stress measurement point. Based on the Brillouin scattering data at each stress measurement point, a Brillouin gain spectrum is generated for each stress measurement point. Each stress measurement point is the center point of the connection between each stress sensing unit and the sensing optical cable. The frequency shift change calculation unit is used to control the Brillouin detection device to perform peak value calculation on each stress measurement point according to the Brillouin gain spectrum of each stress measurement point, so as to obtain the original Brillouin frequency shift change data corresponding to each stress measurement point. The original Brillouin frequency shift change data of each stress measurement point is filtered out for interference using the dual-fiber temperature compensation method and digital filtering algorithm to obtain the Brillouin stress frequency shift change data of each stress measurement point. The lateral offset calculation unit is used to control the Brillouin detection device to acquire the strain key parameters and geometric constraint models of each stress sensing unit. Based on the Brillouin stress frequency shift change data and the strain key parameters of each stress sensing unit at each stress measurement point, the unit calculates the strain value of the sensing optical cable at each stress measurement point. Through the geometric constraint models of each stress sensing unit, the unit converts the strain value of the sensing optical cable at each stress measurement point into the pipeline plane displacement of the chemical pipeline to be monitored at each stress measurement point. The unit decomposes the pipeline plane displacement at each stress measurement point to obtain the lateral offset of the chemical pipeline to be monitored at each stress measurement point. The data analysis and display unit is used to control the Brillouin detection device to visualize and analyze the lateral displacement of the chemical pipeline under monitoring at each stress measurement point, obtain analysis results, generate and issue corresponding prompt information based on the analysis results, and also to receive and issue the prompt information.

[0017] Thirdly, the present invention provides an electronic device comprising a memory, a processor, and a transceiver connected in sequence and communication, wherein the memory is used to store a computer program, the transceiver is used to send and receive messages, and the processor is used to read the computer program and execute the chemical pipeline lateral displacement detection method based on Brillouin stress as described in the first aspect or any possible design of the first aspect.

[0018] Fourthly, the present invention provides a computer-readable storage medium storing instructions that, when executed on a computer, perform the chemical pipeline lateral displacement detection method based on Brillouin stress as described in the first aspect or any possible design of the first aspect.

[0019] Fifthly, the present invention provides a computer program product containing instructions that, when executed on a computer, cause the computer to perform the chemical pipeline lateral displacement detection method based on Brillouin stress as described in the first aspect or any possible design of the first aspect.

[0020] Beneficial Effects: This invention provides a method for detecting lateral displacement of chemical pipelines based on Brillouin stress, comprising: laying a tensioned sensing optical cable along the direction of the chemical pipeline to be monitored; connecting a Brillouin detection device to one end of the sensing optical cable; installing stress sensing units at each key support node of the chemical pipeline to be monitored; and connecting the stress sensing units in series through the sensing optical cable to form a Brillouin stress sensing network. The method is implemented based on the Brillouin stress sensing network and includes: firstly, transmitting a narrow pulse optical signal to the sensing optical cable through the Brillouin detection device, and detecting the signal from the sensing optical cable... A reverse Brillouin scattering light signal is acquired, and photoelectric conversion and signal processing are performed on the reverse Brillouin scattering light signal to obtain Brillouin scattering data for each stress measurement point. Based on the Brillouin scattering data for each stress measurement point, a Brillouin gain spectrum for each stress measurement point is generated, wherein each stress measurement point is the center point of the connection between each stress sensing unit and the sensing optical cable. Next, based on the Brillouin gain spectrum of each stress measurement point, peak values ​​are calculated for each stress measurement point to obtain the peak values ​​for each stress measurement point. The original Brillouin frequency shift variation data for each stress measurement point is processed using a dual-fiber temperature compensation method and a digital filtering algorithm to remove interference, resulting in Brillouin stress frequency shift variation data for each stress measurement point. Then, the strain key parameters and geometric constraint models of each stress sensing unit are acquired. Based on the Brillouin stress frequency shift variation data and the strain key parameters of the stress sensing unit at each stress measurement point, the strain value of the sensing optical cable at each stress measurement point is calculated. The geometric constraint model of the sensing unit converts the strain values ​​of the sensing optical cable at each stress measurement point into the pipe plane displacement of the chemical pipeline to be monitored at each stress measurement point. The pipe plane displacement at each stress measurement point is then decomposed to obtain the lateral offset of the chemical pipeline at each stress measurement point. Finally, the lateral offset of the chemical pipeline at each stress measurement point is visualized and a pipeline safety analysis is performed to obtain the analysis results. Based on the analysis results, corresponding prompts are generated and issued.By setting up sensing optical cables and stress sensing units, a Brillouin stress sensing network corresponding to the chemical pipeline is constructed. This sensing network provides structural support for monitoring the offset of the chemical pipeline, avoiding the need for inspection personnel to enter the hazardous chemical environment, and achieving scene adaptation between the sensing units and the chemical pipeline. Furthermore, the Brillouin detection device performs multi-level processing and interference filtering on the reverse Brillouin scattered light signals at each stress measurement point, calculating the accurate Brillouin stress frequency shift change data at each stress measurement point. Based on key strain parameters and an accurate geometric constraint model, the frequency shift change is converted and decomposed into the lateral offset of the pipeline, resulting in an accurate lateral offset. In addition, real-time detection via sensing optical cables enables unmanned monitoring with low latency and short intervals, generating real-time detection results and issuing alerts, thus avoiding blind spots in safety monitoring. Attached Figure Description

[0021] Figure 1 A schematic flowchart of the lateral displacement detection method for chemical pipelines based on Brillouin stress provided in an embodiment of the present invention; Figure 2 This is a functional structure diagram of the Brillouin detection device provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the stress sensing unit provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the component connections of the Brillouin detection device provided in an embodiment of the present invention; Figure 5 A functional structure diagram of a chemical pipeline lateral displacement detection system based on Brillouin stress provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in conjunction with the accompanying drawings and descriptions of the embodiments or the prior art. Obviously, the following description of the structure of the accompanying drawings is only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It should be noted that the description of these embodiments is for the purpose of helping to understand the present invention, but does not constitute a limitation of the present invention.

[0023] It should be understood that although the terms first, second, etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are only used to distinguish one unit from another. For example, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit, without departing from the scope of the exemplary embodiments of the invention.

[0024] It should be understood that the term "and / or" that may appear in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist simultaneously. The term " / and" that may appear in this document describes another relationship between related objects, indicating that two relationships can exist. For example, A / and B can mean: A exists alone, and A and B exist alone. In addition, the character " / " that may appear in this document generally indicates that the related objects before and after it are in an "or" relationship.

[0025] Example 1: like Figure 1 As shown, the first aspect of this embodiment provides a method for detecting lateral displacement of a chemical pipeline based on Brillouin stress. A tensioned sensing optical cable is laid along the direction of the chemical pipeline to be monitored. A Brillouin detection device is connected to one end of the sensing optical cable. Stress sensing units are installed at each key support node of the chemical pipeline to be monitored, and the stress sensing units are connected in series through the sensing optical cable to form a Brillouin stress sensing network. The method is implemented based on the Brillouin stress sensing network and may include, but is not limited to, the following steps: S1. A narrow pulse light signal is emitted to the sensing optical cable through the Brillouin detection device, and a reverse Brillouin scattered light signal is obtained from the sensing optical cable. The reverse Brillouin scattered light signal is photoelectrically converted and processed to obtain Brillouin scattering data at each stress measurement point. Based on the Brillouin scattering data at each stress measurement point, a Brillouin gain spectrum is generated at each stress measurement point, wherein each stress measurement point is the center point of the connection between each stress sensing unit and the sensing optical cable. S2. Based on the Brillouin gain spectrum of each stress measurement point, peak values ​​are calculated for each stress measurement point to obtain the original Brillouin frequency shift change data corresponding to each stress measurement point. Interference is filtered out from the original Brillouin frequency shift change data of each stress measurement point using the dual-fiber temperature compensation method and digital filtering algorithm to obtain the Brillouin stress frequency shift change data of each stress measurement point. S3. Obtain the strain key parameters and geometric constraint models of each stress sensing unit. Based on the Brillouin stress frequency shift change data and the strain key parameters of each stress sensing unit at each stress measurement point, calculate the strain value of the sensing optical cable at each stress measurement point. Through the geometric constraint models of each stress sensing unit, convert the strain value of the sensing optical cable at each stress measurement point into the pipeline plane displacement of the chemical pipeline to be monitored at each stress measurement point. Decompose the pipeline plane displacement at each stress measurement point to obtain the lateral offset of the chemical pipeline to be monitored at each stress measurement point. S4. Visualize and analyze the lateral offset of the chemical pipeline under monitoring at each stress measurement point, obtain the analysis results, and generate and issue corresponding prompt information based on the analysis results.

[0026] like Figure 2 As shown, in one possible implementation, the Brillouin detection device includes a narrow-pulse laser source, an optical signal processing unit, an electrical signal processing unit, and a data computing terminal. One end of the sensing optical cable is connected to the narrow-pulse laser source and the optical signal processing unit, and the other end of the sensing optical cable is provided with an anti-reflection fiber optic terminator. The output end of the optical signal processing unit is electrically connected to the input end of the electrical signal processing unit, and the output end of the electrical signal processing unit is electrically connected to the data computing terminal. The narrow-pulse laser source is used to emit nanosecond-level optical pulse signals. like Figure 3 As shown, the key support nodes of the chemical pipeline to be monitored include key support points and corresponding supports on the chemical pipeline. Each stress sensing unit includes a wedge, a fixed bracket, a spring, and an optical cable clamp. The wedge is rigidly fixed to each key support point of the chemical pipeline to be monitored. The fixed bracket is fixedly installed on each support of the chemical pipeline to be monitored. The fixed end of the spring is fixedly connected to the fixed bracket. The other end of the spring is rigidly connected to the optical cable clamp. The clamping end of the optical cable clamp is used to clamp the sensing optical cable. The inclined surface of the wedge in each stress sensing unit contacts the open end of the corresponding spring according to a preset pressure. The clamping direction of each optical cable clamp is perpendicular to the axis of the chemical pipeline to be monitored.

[0027] It should be noted that, as Figure 4As shown in the embodiment, the lateral offset detection method for chemical pipelines provided in this example, including but not limited to the following application methods, includes a narrow-pulse laser source comprising a narrow-linewidth DFB laser, a high-speed electro-optic modulator, and an erbium-doped fiber amplifier connected in sequence. The narrow-linewidth DFB laser provides stable, monochromatic continuous light (preferably set to 1550 nm), which is then modulated by the high-speed electro-optic modulator into a pre-narrow-pulse optical pulse signal (nanosecond level) for positioning. The erbium-doped fiber amplifier amplifies the power of the pre-narrow-pulse optical pulse signal to a level sufficient to excite effective Brillouin scattering, forming a narrow-pulse optical pulse signal, which is then emitted to the sensing optical cable. The optical signal processing unit includes an avalanche photodiode, which is used to acquire a weak Brillouin scattering light signal (i.e., a reverse Brillouin scattering light signal) from the sensing optical cable and convert it into a corresponding electrical signal (i.e., the original Brillouin scattering radio frequency electrical signal), which is then sent to the electrical signal processing unit. The electrical signal processing unit comprises a power amplifier, a bandpass filter, and a high-speed, high-resolution analog-to-digital converter connected in sequence. The power amplifier, which may be a low-noise amplifier, is used to pre-amplify the weak original Brillouin scattering radio frequency signal to improve the signal-to-noise ratio. The bandpass filter (corresponding to the continuous light in the 1550nm band mentioned above, with a center frequency of 11GHz and a bandwidth of 100MHz) is used to filter out broadband noise and spontaneous emission noise introduced during amplification, retaining only the useful frequency band containing Brillouin frequency shift information. The analog-to-digital converter is used to accurately capture the waveform information of the processed original Brillouin scattering radio frequency signal based on the Nyquist sampling theorem, digitize it into the global Brillouin scattering data, and output it to the data computing terminal. The data computing terminal includes an industrial computer and / or an embedded processor, used to perform all algorithmic functions such as spectrum analysis, frequency shift extraction, temperature compensation, displacement conversion, and enhancement information generation.

[0028] Furthermore, in the chemical pipeline lateral offset detection method provided in this embodiment, in example but not limited to the following application, the narrow pulse laser source and the avalanche photodiode are connected to the sensing optical cable through a circulator. The circulator is a three-port passive optical device, with its first port located at the emitting end of the narrow pulse laser source, its second port connected to the terminal of the sensing optical cable through a single-mode fiber jumper, and its third port located at the receiving end of the avalanche photodiode, for realizing unidirectional separation between the narrow pulse optical pulse signal and the reverse Brillouin scattering optical signal.

[0029] In one possible implementation, step S1 involves transmitting a narrow pulse light signal to the sensing optical cable via the Brillouin detection device and acquiring a reverse Brillouin scattering light signal from the sensing optical cable. The reverse Brillouin scattering light signal is then subjected to photoelectric conversion and signal processing to obtain Brillouin scattering data for each stress measurement point. Based on this Brillouin scattering data, a Brillouin gain spectrum for each stress measurement point is generated. This step can be decomposed, but is not limited to, steps S11-S14, specifically including: S11. A narrow pulse light signal is emitted to the sensing optical cable through the narrow pulse laser source in the Brillouin detection device, and the reverse Brillouin scattered light signal is obtained from the sensing optical cable through the optical signal processing unit in the Brillouin detection device. S12. The optical signal processing unit performs photoelectric conversion on the reverse Brillouin scattering optical signal to generate the original Brillouin scattering radio frequency electrical signal, and outputs the original Brillouin scattering radio frequency electrical signal to the electrical signal processing unit. S13. The original Brillouin scattering radio frequency signal is amplified and bandpass filtered by the electrical signal processing unit to obtain a Brillouin scattering radio frequency signal. The Brillouin scattering radio frequency signal is then converted from analog to digital by the electrical signal processing unit to obtain global Brillouin scattering data. The global Brillouin scattering data is then output to the data computing terminal. S14. Obtain preset stress measurement point information through the data computing terminal, perform point mapping on the global Brillouin scattering data according to the stress measurement point information to obtain Brillouin scattering data of each stress measurement point, and perform short-time Fourier transform analysis on the Brillouin scattering data of each stress measurement point through the data computing terminal to obtain the Brillouin gain spectrum of each stress measurement point.

[0030] It should be noted that the lateral displacement detection method for chemical pipelines provided in this embodiment, through the fusion design of mechanical linkage and fiber optic sensing, converts the physical displacement of the chemical pipeline into optical signal changes without loss. By utilizing Brillouin scattering technology, it achieves millisecond-level continuous acquisition of various stress measurement points. This monitoring data acquisition method replaces the high-risk, high-cost, low-efficiency, and low-precision manual inspection, transforming the monitoring behavior from intermittent spot checks to continuous global detection. It can completely capture various instantaneous displacement events, including pump start-up and shutdown impacts, and realize uninterrupted monitoring of chemical pipelines. This greatly improves the timeliness and reliability of monitoring and provides an accurate and timely time window for preventing chemical accidents.

[0031] In one possible implementation, before obtaining the preset stress measurement point information through the data calculation terminal in step S2, the following steps S201-S204 may also be included, but are not limited to: S201. After the Brillouin stress sensing network is deployed, the data computing terminal obtains the emission time of each narrow pulse light signal emitted by the narrow pulse laser source and the reception time of each reverse Brillouin scattered light signal received by the optical signal processing unit. S202. Based on the emission time of each narrow pulse optical signal and the reception time of each reverse Brillouin scattering optical signal, calculate the propagation time of multiple optical signals, and based on the principle of optical time-domain reflection, calculate the corresponding propagation distance of multiple optical signals using the propagation time of each optical signal, and use the propagation distance of each optical signal as the distance of multiple sensing optical cables. S203. Obtain the number information of each stress sensing unit in the Brillouin stress sensing network, match the number information of each stress sensing unit with the distance of each sensing optical cable to form multiple stress measurement points, and add the distance of each sensing optical cable to each stress measurement point to obtain stress measurement point information. S204. Store the stress measurement point information into the data calculation terminal.

[0032] In one possible implementation, step S2 involves calculating the peak value of each stress measurement point based on its Brillouin gain spectrum to obtain the original Brillouin frequency shift change data corresponding to each stress measurement point. This can be decomposed, but is not limited to, steps S21-S22, specifically including: S21. Using the data calculation terminal, perform peak value calculation on the Brillouin gain spectrum of each stress measurement point to extract the peak frequency of the Brillouin gain spectrum of each stress measurement point, wherein the peak value calculation includes Lorentz curve fitting or Voigt curve fitting. S22. Obtain the preset reference calibration frequency of each stress measurement point, calculate the corresponding difference between the peak frequency of the Brillouin gain spectrum of each stress measurement point and the reference calibration frequency of each stress measurement point, and obtain the original Brillouin frequency shift change corresponding to each stress measurement point.

[0033] In one possible implementation, after forming the Brillouin stress sensing network, a reference optical cable identical to the sensing optical cable is laid in parallel with the sensing optical cable according to the Brillouin stress sensing network, and the reference optical cable does not mechanically contact each of the stress sensing units.

[0034] In one possible implementation, step S2 involves using a dual-fiber temperature compensation method and a digital filtering algorithm to filter out interference from the original Brillouin frequency shift variation data at each stress measurement point, thereby obtaining the Brillouin stress frequency shift variation data at each stress measurement point. This step can be decomposed, but is not limited to, the following steps S23-S27, specifically including: S23. A narrow pulse optical signal is synchronously emitted to the reference optical cable through the narrow pulse laser source, and a reverse Brillouin scattering reference signal is obtained from the reference optical cable through the optical signal processing unit; S24. The optical signal processing unit and the electrical signal processing unit perform photoelectric conversion and signal processing on the reverse Brillouin scattering light reference signal to obtain global Brillouin scattering reference data. The data computing terminal calculates the Brillouin scattering reference data of each stress measurement point based on the global Brillouin scattering reference data, so as to generate the reference Brillouin gain spectrum of each stress measurement point based on the Brillouin scattering reference data of each stress measurement point. S25. Calculate the peak value of the reference Brillouin gain spectrum of each stress measurement point to obtain the reference Brillouin frequency shift change data of each reference Brillouin gain spectrum, and use the reference Brillouin frequency shift change data of each reference Brillouin gain spectrum as the temperature interference of each stress measurement point. S26. Based on the dual-fiber temperature compensation method, the original Brillouin frequency shift change data of each stress measurement point are subtracted by the temperature interference term of each stress measurement point to complete the temperature interference filtering and obtain the pre-Brillouin stress frequency shift change data of each stress measurement point. S27. Based on a digital filtering algorithm, electromagnetic interference is filtered out from the pre-Brillouin stress frequency shift change data of each stress measurement point to obtain the Brillouin stress frequency shift change data of each stress measurement point. The digital filtering algorithm includes a sliding filter algorithm or a wavelet denoising algorithm.

[0035] It should be noted that the chemical pipeline lateral offset detection method provided in this embodiment adopts a strategy that combines dual-fiber differential temperature compensation method with digital filtering algorithm. It effectively removes the interference of temperature fluctuation and electromagnetic noise on the Brillouin stress frequency shift change data from both hardware and algorithm dimensions, so that the final Brillouin stress frequency shift change data is highly pure, which lays a solid data foundation for subsequent high-precision displacement inversion and ensures the high-precision realization of pipeline lateral offset calculation.

[0036] In one possible implementation, step S3 involves acquiring the strain key parameters and geometric constraint models of each stress sensing unit, and calculating the strain value of the sensing optical cable at each stress measurement point based on the Brillouin stress frequency shift change data at each stress measurement point and the strain key parameters of each stress sensing unit. This step can be decomposed, but is not limited to, the following steps S31-S32, specifically including: S31. Obtain the strain key parameters of each stress sensing unit through the data calculation terminal, wherein the strain key parameters include the calibration strain coefficient and the tension reference length of the sensing optical cable, and the tension reference length of the sensing optical cable is used to represent the effective sensing section length of the sensing optical cable between adjacent stress measurement points. S32. Based on the calibrated strain coefficient of each stress sensing unit, the strain value of the sensing optical cable corresponding to each stress measurement point is calculated using the following formula (1) for the Brillouin stress frequency shift change data at each stress measurement point: (1) in, This indicates the strain value of the sensing optical cable at the stress measurement point. This represents the Brillouin stress frequency shift variation data at the stress measurement point. This represents the calibrated strain coefficient of the stress sensing unit.

[0037] In one possible implementation, in step S3, the strain value of the sensing optical cable at each stress measurement point is converted into the pipe plane displacement of the chemical pipeline to be monitored at each stress measurement point using the geometric constraint model of each stress sensing unit. The pipe plane displacement at each stress measurement point is then decomposed to obtain the lateral offset of the chemical pipeline to be monitored at each stress measurement point. This decomposition can be, but is not limited to, the following steps S33-S36, specifically including: S33. Based on the tension reference length of the sensing optical cable, the spring body deformation of the spring body corresponding to each stress measurement point is calculated using the following formula (2): (2) in, This represents the spring body deformation corresponding to the stress measurement point. This indicates the tension reference length of the sensing optical cable; S34. Obtain the geometric constraint model of each stress sensing unit through the data calculation terminal, wherein the geometric constraint model includes wedge size parameters, wedge tilt angle parameters and wedge inclined surface displacement transfer ratio; S35. Based on the displacement transfer ratio of the wedge-shaped inclined surface, the spring body deformation of each stress measurement point is decomposed by the following formula (3) to be converted into the pipe plane displacement corresponding to each stress measurement point. (3) in, This indicates the amount of planar displacement of the pipe at the stress measurement point. This indicates the displacement transfer ratio of the wedge-shaped inclined surface; S36. Based on the wedge inclination angle parameter, the pipe plane displacement at each stress measurement point is decomposed into the pipe lateral offset corresponding to each stress measurement point by the following formula (4); (4) in, This indicates the lateral offset of the pipe at the stress measurement point. This represents the inclination angle parameter of the wedge.

[0038] It should be noted that the lateral offset detection method for chemical pipelines provided in this embodiment establishes a rigorous mathematical conversion model between frequency shift change and pipeline lateral offset. This model not only quantifies the deformation of the spring body by calibrating the strain coefficient, but also accurately calculates and ultimately decomposes the lateral offset of the pipeline at the stress measurement point through a geometric constraint model. This makes the monitoring results accurate to the quantified value of the lateral offset of the chemical pipeline under test, and, where possible, can output accurate vector information of the offset, realizing the advancement of chemical pipeline from fuzzy inspection and early warning to precise quantitative offset detection.

[0039] In one possible implementation, step S4 involves visualizing and analyzing the lateral offset of the monitored chemical pipeline at each stress measurement point, obtaining analysis results, and generating and issuing corresponding prompts based on the analysis results. This step can be broken down into, but is not limited to, the following steps S41-S45, specifically including: S41. The data calculation terminal integrates the lateral offsets of each pipeline obtained at different sampling times to draw a curve showing the relationship between the lateral offset of the pipeline and time, which serves as a real-time trend chart for the pipeline safety analysis of the chemical pipeline to be monitored. S42. Through the data calculation terminal, generate corresponding real-time result display signals for the lateral displacement of the pipeline at each stress measurement point and the real-time analysis trend of the pipeline safety of the chemical pipeline under monitoring, and send the real-time result display signals to the display screen to visualize the lateral displacement of the pipeline at each stress measurement point and the real-time analysis trend of the pipeline safety of the chemical pipeline under monitoring. S43. Obtain a preset pipeline lateral offset warning threshold through the data calculation terminal, and perform pipeline safety analysis on the pipeline lateral offset at each stress measurement point according to the pipeline lateral offset warning threshold to obtain the analysis results; S44. If the analysis result indicates that the lateral offset of the pipeline at the stress measurement point does not exceed the lateral offset warning threshold, then a pipeline safety warning message is generated and sent to the safety management server. S45. If the analysis result indicates that the lateral offset of the pipeline at the stress measurement point exceeds the lateral offset warning threshold, then a pipeline anomaly alert is generated and sent to the safety management server.

[0040] It should be noted that the lateral offset detection method for chemical pipelines provided in this embodiment aggregates the real-time lateral offset of the pipeline and the real-time pipeline safety analysis trend chart of the monitored chemical pipeline to the safety management server in real time, and integrates early warning analysis (pipeline safety analysis) and real-time prompt functions. Maintenance personnel only need to log in to the safety management server to observe the real-time lateral offset of the chemical pipeline and the real-time pipeline safety analysis trend chart in real time and receive prompt information. Based on the real-time lateral offset of the chemical pipeline, the real-time pipeline safety analysis trend chart and the prompt information, it is possible to clearly distinguish whether the monitored pipeline has horizontal collision risk and / or vertical delamination and settlement, thereby taking targeted measures. This realizes the intelligent transformation from post-maintenance to pre-prevention and predictive maintenance, greatly reducing maintenance costs and monitoring efficiency.

[0041] like Figure 5 As shown, the second aspect of this embodiment provides a system for implementing the lateral displacement detection method for chemical pipelines based on Brillouin stress described in the first aspect of the embodiment. The lateral displacement detection system for chemical pipelines based on Brillouin stress is installed in a safety management server, which is communicatively connected to the Brillouin detection device. The system includes: The detection start unit is used to send a detection start signal to the Brillouin detection device, emit a narrow pulse light signal to the sensing optical cable, and obtain a reverse Brillouin scattering light signal from the sensing optical cable. The reverse Brillouin scattering light signal is then photoelectrically converted and processed to obtain Brillouin scattering data at each stress measurement point. Based on the Brillouin scattering data at each stress measurement point, a Brillouin gain spectrum is generated for each stress measurement point. Each stress measurement point is the center point of the connection between each stress sensing unit and the sensing optical cable. The frequency shift change calculation unit is used to control the Brillouin detection device to perform peak value calculation on each stress measurement point according to the Brillouin gain spectrum of each stress measurement point, so as to obtain the original Brillouin frequency shift change data corresponding to each stress measurement point. The original Brillouin frequency shift change data of each stress measurement point is filtered out for interference using the dual-fiber temperature compensation method and digital filtering algorithm to obtain the Brillouin stress frequency shift change data of each stress measurement point. The lateral offset calculation unit is used to control the Brillouin detection device to acquire the strain key parameters and geometric constraint models of each stress sensing unit. Based on the Brillouin stress frequency shift change data and the strain key parameters of each stress sensing unit at each stress measurement point, the unit calculates the strain value of the sensing optical cable at each stress measurement point. Through the geometric constraint models of each stress sensing unit, the unit converts the strain value of the sensing optical cable at each stress measurement point into the pipeline plane displacement of the chemical pipeline to be monitored at each stress measurement point. The unit decomposes the pipeline plane displacement at each stress measurement point to obtain the lateral offset of the chemical pipeline to be monitored at each stress measurement point. The data analysis and display unit is used to control the Brillouin detection device to visualize and analyze the lateral displacement of the chemical pipeline under monitoring at each stress measurement point, obtain analysis results, generate and issue corresponding prompt information based on the analysis results, and also to receive and issue the prompt information.

[0042] The working process, working details and technical effects of the system provided in this embodiment can be found in the first aspect of the embodiment, and will not be repeated here.

[0043] like Figure 6 As shown, the third aspect of this embodiment provides an electronic device, including: a memory, a processor, and a transceiver that are sequentially and communicatively connected, wherein the memory is used to store a computer program, the transceiver is used to send and receive messages, and the processor is used to read the computer program and execute the chemical pipeline lateral displacement detection method based on Brillouin stress as described in the first aspect of the embodiment.

[0044] For specific examples, the memory may include, but is not limited to, random access memory (RAM), read-only memory (ROM), flash memory, first-in-first-out (FIFO) memory, and / or first-in-last-out (FILO) memory, etc.; specifically, the processor may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor may be implemented using at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), PLA (Programmable Logic Array). The processor may also include a main processor and a coprocessor. The main processor, also known as the CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state.

[0045] In some embodiments, the processor may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the screen. For example, the processor may not be limited to microprocessors of the STM32F105 series, reduced instruction set computer (RISC) microprocessors, x86 architecture processors, or processors with integrated neural network processing units (NPUs). The transceiver may be, but is not limited to, a Wi-Fi transceiver, a Bluetooth transceiver, a General Packet Radio Service (GPRS) transceiver, a ZigBee transceiver (a low-power LAN protocol based on the IEEE 802.15.4 standard), a 3G transceiver, a 4G transceiver, and / or a 5G transceiver. Furthermore, the device may also include, but is not limited to, a power module, a display screen, and other necessary components.

[0046] The working process, working details and technical effects of the electronic device provided in this embodiment can be found in the first aspect of the embodiment, and will not be repeated here.

[0047] The fourth aspect of this embodiment provides a storage medium that stores instructions containing the instructions for the chemical pipeline lateral offset detection method based on Brillouin stress as described in the first aspect of the embodiment. That is, the storage medium stores instructions that, when executed on a computer, perform the chemical pipeline lateral offset detection method based on Brillouin stress as described in the first aspect of the embodiment.

[0048] The storage medium refers to a carrier for storing data, which may include, but is not limited to, floppy disks, optical disks, hard disks, flash memory, USB flash drives, and / or memory sticks. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.

[0049] The working process, working details and technical effects of the storage medium provided in this embodiment can be found in the first aspect of the embodiment, and will not be repeated here.

[0050] The fifth aspect of this embodiment provides a computer program product containing instructions that, when executed on a computer, cause the computer to perform the chemical pipeline lateral displacement detection method based on Brillouin stress as described in the first aspect of this embodiment, wherein the computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device.

[0051] Example 2: This embodiment provides a design and installation method for a Brillouin stress sensing network. By using an integrated installation structure of "mechanical linkage-fiber sensing" adapted to the highly corrosive, high-temperature and high-pressure environment of chemical industry, the lateral displacement of chemical pipelines (horizontal collision, vertical settlement / bulging) is converted into the tensile / compressive strain of the sensing optical cable. Then, the Brillouin scattering effect is used to achieve accurate acquisition of the strain value of the sensing optical cable. Finally, the lateral displacement of the chemical pipeline is inverted through a geometric constraint model to form a closed loop of full-chain monitoring.

[0052] Due to the characteristics of chemical pipelines, such as strong corrosion, high temperature, and multi-directional displacement, this embodiment designs a four-stage linkage installation structure consisting of a wedge, a spring, an optical cable clamp, and a fixed bracket. This ensures that the physical displacement of the chemical pipeline can be transmitted to the sensing optical cable without loss. The specific installation steps and processes are as follows: In view of the fact that chemical pipelines are mostly fixed to I-beam supports, a linkage structure of wedge and spring is installed at the key support point (support) of each chemical pipeline to be tested to achieve interference-free transmission of offset direction: The wedge is made of 45# steel to form a right trapezoidal wedge (its upper base length L1=120mm, lower base length L2=80mm, height H=30mm, to adapt to the lateral offset range of the chemical pipeline). It is double fixed to the flange plate of the I-beam support on the side of the chemical pipeline using high-temperature resistant epoxy adhesive (temperature resistance above 200℃) and M8 stainless steel bolts to ensure that there is no relative sliding between the wedge and the pipeline.

[0053] A U-shaped slot is welded onto a fixed bracket (made of 316L stainless steel to prevent chemical corrosion). A spring body (made of stainless steel with a stiffness coefficient k=5N / mm and a deformation range of ±40mm to accommodate the lateral offset range of the chemical pipeline) is fixedly connected to an optical cable clamp (the clamping end is equipped with an inner silicone pad to prevent the sensing optical cable from being squeezed and damaged) to form a sensing component. The spring body is embedded in the U-shaped slot: one end of the spring body is welded and fixed to the U-shaped slot, and the other end is in close contact with the inclined surface of the wedge (the preset pressure is set to 50N to ensure that a small offset can trigger the deformation of the spring body); the clamping end of the optical cable clamp clamps the sensing optical cable, and the axis of the sensing optical cable is perpendicular to the axis of the chemical pipeline (to ensure that the lateral offset of the chemical pipeline can be converted into the axial strain value of the sensing optical cable without loss).

[0054] Optical cable cross-bracing fixing: Between each strain sensing unit, 3mm stainless steel wire rope (corrosion resistant, tensile strength ≥500MPa) is used to tension and fix the sensing optical cable (selecting optical cables with stainless steel armor and copper foil shielding layers as sensing optical cables to avoid chemical corrosion and effectively shield electromagnetic interference from electromagnetic fields along the way to the internal optical fibers of the sensing optical cable) between adjacent strain sensing units. The tension force is controlled at 100-150N (to avoid the optical cable slack causing offset transmission lag). Each strain sensing unit serves as a stress measurement point (the optical cable clamp position is the center of the point). The distance between points is consistent with the distance between supports and hangers (generally set at 8-12m) to achieve full coverage monitoring of the chemical pipeline.

[0055] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for detecting lateral displacement of chemical pipelines based on Brillouin stress, characterized in that, A taut sensing optical cable is laid along the route of the chemical pipeline to be monitored. A Brillouin detection device is connected to one end of the sensing optical cable. Stress sensing units are installed at each key support node of the chemical pipeline to be monitored, and the stress sensing units are connected in series through the sensing optical cable to form a Brillouin stress sensing network. The method is implemented based on the Brillouin stress sensing network and includes: The Brillouin detection device emits a narrow pulse light signal to the sensing optical cable and obtains a reverse Brillouin scattered light signal from the sensing optical cable. The reverse Brillouin scattered light signal is photoelectrically converted and processed to obtain Brillouin scattering data for each stress measurement point. Based on the Brillouin scattering data for each stress measurement point, a Brillouin gain spectrum for each stress measurement point is generated. Each stress measurement point is the center point of the connection between each stress sensing unit and the sensing optical cable. Based on the Brillouin gain spectrum of each stress measurement point, peak values ​​are calculated for each stress measurement point to obtain the original Brillouin frequency shift change data corresponding to each stress measurement point. Interference is filtered out from the original Brillouin frequency shift change data of each stress measurement point using the dual-fiber temperature compensation method and digital filtering algorithm to obtain the Brillouin stress frequency shift change data of each stress measurement point. The strain key parameters and geometric constraint models of each stress sensing unit are obtained. Based on the Brillouin stress frequency shift change data and the strain key parameters of each stress sensing unit at each stress measurement point, the strain value of the sensing optical cable at each stress measurement point is calculated. Through the geometric constraint model of each stress sensing unit, the strain value of the sensing optical cable at each stress measurement point is converted into the pipeline plane displacement of the chemical pipeline to be monitored at each stress measurement point. The pipeline plane displacement at each stress measurement point is decomposed to obtain the lateral offset of the chemical pipeline to be monitored at each stress measurement point. The lateral offset of the monitored chemical pipeline at each stress measurement point is visualized and analyzed for pipeline safety. The analysis results are obtained, and corresponding prompts are generated and issued based on the analysis results.

2. The method for detecting lateral displacement of chemical pipelines based on Brillouin stress according to claim 1, characterized in that, The Brillouin detection device includes a narrow pulse laser source, an optical signal processing unit, an electrical signal processing unit, and a data computing terminal. One end of the sensing optical cable is connected to the narrow pulse laser source and the optical signal processing unit, and the other end of the sensing optical cable is provided with an anti-reflection fiber optic terminator. The output end of the optical signal processing unit is electrically connected to the input end of the electrical signal processing unit, and the output end of the electrical signal processing unit is electrically connected to the data computing terminal. The narrow pulse laser source is used to emit nanosecond-level optical pulse signals. The key support nodes of the chemical pipeline to be monitored include key support points and corresponding supports on the chemical pipeline. Each stress sensing unit includes a wedge, a fixed bracket, a spring, and an optical cable clamp. The wedge is rigidly fixed to each key support point of the chemical pipeline to be monitored. The fixed bracket is fixedly installed on each support of the chemical pipeline to be monitored. The fixed end of the spring is fixedly connected to the fixed bracket. The other end of the spring is rigidly connected to the optical cable clamp. The clamping end of the optical cable clamp is used to clamp the sensing optical cable. The inclined surface of the wedge in each stress sensing unit contacts the open end of the corresponding spring according to a preset pressure. The clamping direction of each optical cable clamp is perpendicular to the axis of the chemical pipeline to be monitored.

3. The method for detecting lateral displacement of chemical pipelines based on Brillouin stress according to claim 2, characterized in that, The Brillouin detection device emits a narrow pulse light signal to the sensing optical cable and acquires a reverse Brillouin scattering light signal from the sensing optical cable. The reverse Brillouin scattering light signal is then photoelectrically converted and processed to obtain Brillouin scattering data for each stress measurement point. Based on the Brillouin scattering data for each stress measurement point, a Brillouin gain spectrum for each stress measurement point is generated, including: A narrow pulse light signal is emitted to the sensing optical cable through the narrow pulse laser source in the Brillouin detection device, and the reverse Brillouin scattered light signal is obtained from the sensing optical cable through the optical signal processing unit in the Brillouin detection device. The optical signal processing unit performs photoelectric conversion on the reverse Brillouin scattering optical signal to generate the original Brillouin scattering radio frequency electrical signal, and outputs the original Brillouin scattering radio frequency electrical signal to the electrical signal processing unit. The original Brillouin scattering radio frequency signal is amplified and bandpass filtered by the electrical signal processing unit to obtain a Brillouin scattering radio frequency signal. The Brillouin scattering radio frequency signal is then converted from analog to digital by the electrical signal processing unit to obtain global Brillouin scattering data. The global Brillouin scattering data is then output to the data computing terminal. The data computing terminal acquires preset stress measurement point information, maps the global Brillouin scattering data according to the stress measurement point information, obtains Brillouin scattering data for each stress measurement point, and performs short-time Fourier transform analysis on the Brillouin scattering data for each stress measurement point through the data computing terminal to obtain the Brillouin gain spectrum for each stress measurement point.

4. The method for detecting lateral displacement of chemical pipelines based on Brillouin stress according to claim 3, characterized in that, Before acquiring the preset stress measurement point information through the data calculation terminal, the process also includes: After the Brillouin stress sensing network is deployed, the data computing terminal obtains the emission time of each narrow pulse light signal emitted by the narrow pulse laser source and the reception time of each reverse Brillouin scattered light signal received by the optical signal processing unit. Based on the emission time of each narrow pulse optical signal and the reception time of each reverse Brillouin scattering optical signal, the propagation time of multiple optical signals is calculated. Based on the principle of optical time-domain reflection, the propagation distance of each optical signal is calculated using the propagation time of each optical signal. The propagation distance of each optical signal is then used as the distance of multiple sensing optical cables. In the Brillouin stress sensing network, the numbering information of each stress sensing unit is obtained, and the numbering information of each stress sensing unit is matched one-to-one with the distance of each sensing optical cable to form multiple stress measurement points. The distance of each sensing optical cable is added to each stress measurement point to obtain stress measurement point information. The stress measurement point information is stored in the data computing terminal.

5. The method for detecting lateral displacement of chemical pipelines based on Brillouin stress according to claim 2, characterized in that, Based on the Brillouin gain spectrum of each stress measurement point, peak values ​​are calculated for each stress measurement point to obtain the original Brillouin frequency shift change data corresponding to each stress measurement point, including: The peak value of the Brillouin gain spectrum at each stress measurement point is calculated using the data calculation terminal to extract the peak frequency of the Brillouin gain spectrum at each stress measurement point. The peak value calculation includes Lorentz curve fitting or Voigt curve fitting. Obtain the preset reference calibration frequency for each stress measurement point, calculate the corresponding difference between the peak frequency of the Brillouin gain spectrum of each stress measurement point and the reference calibration frequency of each stress measurement point, and obtain the original Brillouin frequency shift change corresponding to each stress measurement point.

6. The method for detecting lateral displacement of chemical pipelines based on Brillouin stress according to claim 2, characterized in that, After forming the Brillouin stress sensing network, a reference optical cable, identical to the sensing optical cable, is laid in parallel with the sensing optical cable according to the Brillouin stress sensing network, and the reference optical cable does not mechanically contact each of the stress sensing units.

7. The method for detecting lateral displacement of chemical pipelines based on Brillouin stress according to claim 6, characterized in that, Interference was filtered out from the original Brillouin frequency shift variation data at each stress measurement point using a dual-fiber temperature compensation method and a digital filtering algorithm, resulting in Brillouin stress frequency shift variation data for each stress measurement point, including: The narrow pulse laser source synchronously emits a narrow pulse optical signal to the reference optical cable, and the optical signal processing unit obtains the reverse Brillouin scattering reference signal from the reference optical cable. The optical signal processing unit and the electrical signal processing unit perform photoelectric conversion and signal processing on the reverse Brillouin scattering light reference signal to obtain global Brillouin scattering reference data. The data computing terminal then calculates the Brillouin scattering reference data for each stress measurement point based on the global Brillouin scattering reference data, thereby generating a reference Brillouin gain spectrum for each stress measurement point. Peak values ​​are calculated for the reference Brillouin gain spectra at each stress measurement point to obtain reference Brillouin frequency shift data for each reference Brillouin gain spectrum. The reference Brillouin frequency shift data for each reference Brillouin gain spectrum is used as the temperature interference at each stress measurement point. Based on the dual-fiber temperature compensation method, the original Brillouin frequency shift change data of each stress measurement point are subtracted by the temperature interference term of each stress measurement point to complete the temperature interference filtering and obtain the pre-Brillouin stress frequency shift change data of each stress measurement point. Based on a digital filtering algorithm, electromagnetic interference is filtered out from the pre-Brillouin stress frequency shift change data of each stress measurement point to obtain the Brillouin stress frequency shift change data of each stress measurement point. The digital filtering algorithm includes a sliding filter algorithm or a wavelet denoising algorithm.

8. The method for detecting lateral displacement of chemical pipelines based on Brillouin stress according to claim 2, characterized in that, Obtain the strain key parameters and geometric constraint models of each stress sensing unit. Based on the Brillouin stress frequency shift variation data at each stress measurement point and the strain key parameters of each stress sensing unit, calculate the strain value of the sensing optical cable at each stress measurement point, including: The data calculation terminal obtains the strain key parameters of each stress sensing unit, wherein the strain key parameters include the calibration strain coefficient and the tension reference length of the sensing optical cable, and the tension reference length of the sensing optical cable is used to represent the effective sensing section length of the sensing optical cable between adjacent stress measurement points. Based on the calibrated strain coefficient of each stress sensing unit, the strain value of the sensing optical cable corresponding to each stress measurement point is calculated using the following formula (1): （1） in, This indicates the strain value of the sensing optical cable at the stress measurement point. This represents the Brillouin stress frequency shift variation data at the stress measurement point. This represents the calibrated strain coefficient of the stress sensing unit.

9. The method for detecting lateral displacement of chemical pipelines based on Brillouin stress according to claim 8, characterized in that, Using the geometric constraint model of each stress sensing unit, the strain value of the sensing optical cable at each stress measurement point is converted into the pipe plane displacement of the chemical pipeline under monitoring at each stress measurement point. The pipe plane displacement at each stress measurement point is then decomposed to obtain the lateral offset of the chemical pipeline under monitoring at each stress measurement point, including: Based on the tension reference length of the sensing optical cable, the spring body deformation of the spring body corresponding to each stress measurement point is calculated using the following formula (2): （2） in, This represents the spring body deformation corresponding to the stress measurement point. This indicates the tension reference length of the sensing optical cable; The geometric constraint model of each stress sensing unit is obtained through the data computing terminal, wherein the geometric constraint model includes wedge size parameters, wedge tilt angle parameters and wedge inclined surface displacement transfer ratio; Based on the displacement transmission ratio of the wedge-shaped inclined surface, the spring body deformation of each stress measurement point is decomposed by the following formula (3) to be converted into the pipe plane displacement corresponding to each stress measurement point. （3） in, This indicates the amount of planar displacement of the pipe at the stress measurement point. This indicates the displacement transfer ratio of the wedge-shaped inclined surface; Based on the wedge inclination angle parameter, the pipe plane displacement at each stress measurement point is decomposed into the pipe lateral offset corresponding to each stress measurement point by the following formula (4); （4） in, This indicates the lateral offset of the pipe at the stress measurement point. This represents the inclination angle parameter of the wedge.

10. The method for detecting lateral displacement of chemical pipelines based on Brillouin stress according to claim 2, characterized in that, The lateral offset of the monitored chemical pipeline at each stress measurement point is visualized and analyzed for pipeline safety. Analysis results are obtained, and corresponding prompts are generated and issued based on these results, including: The data computing terminal integrates the lateral offsets of various pipelines obtained at different sampling times to draw a curve showing the relationship between the lateral offset of the pipeline and time, which serves as a real-time trend chart for the pipeline safety analysis of the chemical pipeline to be monitored. Through the data computing terminal, the real-time result display signal is generated for the lateral displacement of the pipeline at each stress measurement point and the real-time analysis trend of the pipeline safety of the chemical pipeline under monitoring. The real-time result display signal is then sent to the display screen to visualize the lateral displacement of the pipeline at each stress measurement point and the real-time analysis trend of the pipeline safety of the chemical pipeline under monitoring. The preset pipeline lateral offset warning threshold is obtained through the data calculation terminal. Based on the pipeline lateral offset warning threshold, the pipeline safety analysis is performed on the pipeline lateral offset at each stress measurement point to obtain the analysis results. If the analysis result indicates that the lateral offset of the pipeline at the stress measurement point does not exceed the lateral offset warning threshold, then a pipeline safety warning message is generated and sent to the safety management server. If the analysis result indicates that the lateral offset of the pipeline at the stress measurement point exceeds the lateral offset warning threshold, a pipeline anomaly alert is generated and sent to the safety management server.

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