Water pipeline safety monitoring system based on optical fiber vibration and underwater acoustic sensing

Abstract

The utility model discloses a water delivery pipeline safety monitoring system based on optical fiber vibration and underwater sound sensing, which relates to the field of optical fiber sensing and water delivery monitoring, and comprises a distributed optical fiber sound wave vibration monitoring subsystem which comprises a distributed optical fiber sound wave vibration demodulation device and a distributed optical fiber, and the distributed optical fiber is tightly arranged on the outer wall of a pipeline; the interference type quasi-distribution optical fiber hydrophone subsystem comprises an interference type quasi-distribution optical fiber hydrophone demodulation device, an optical fiber hydrophone and an interference type optical fiber, and the optical fiber hydrophone is fixed to the outer wall of the pipeline through a rigid shell; the signal fusion analysis subsystem is used for receiving data of the interference type quasi-distributed optical fiber hydrophone demodulation device and the distributed optical fiber sound wave vibration demodulation device at the same time; the pipeline safety monitoring platform software is used for receiving the data analyzed and identified by the signal fusion analysis subsystem and carrying out visualization processing; and the synchronous time service device is used for carrying out synchronous time service through the standard clock source. The problem of leakage monitoring and positioning in the water conveying pipeline is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of optical fiber sensing and water transportation monitoring, and particularly relates to a water transportation pipeline safety monitoring system based on optical fiber vibration and underwater acoustic sensing. BACKGROUND

[0002] Underground pipeline transportation has the advantages of safety and reliability, large transportation capacity, no occupation of surface space, and low energy consumption, and therefore has been widely applied. However, water supply pipelines are often buried underground and are difficult to be promptly investigated and handled, and in the past, water resources were regarded as ordinary resources, so online leakage monitoring is rarely used in engineering construction. There are many leakage problems in urban underground water supply networks, and the currently mainly used monitoring methods include regional metering (metering table), detection by detection personnel through special sound transmission tools such as leak detection rods and detectors, and leak detection methods. However, these methods are not suitable for large, long-distance, high-pressure water transportation pipelines.

[0003] After the pipeline is put into use, it will be affected by the environment and will exhibit natural aging phenomena such as thermal expansion and contraction, corrosion and rust, and at the same time, due to the natural settlement of the surface and backfill foundation and the influence of surrounding construction, the pipeline will continuously and slowly leak, which is not easy to be detected, resulting in waste of water resources. If the leakage problem is ignored, for high-pressure water transportation pipelines, it will further increase the risk of pipe explosion and cause serious safety accidents.

[0004] Currently, there have been some related researches on leakage and early warning of long-distance pressure water transportation pipeline projects, but generally they are separate distributed optical fiber sensing and separate electrical hydrophone related methods. Under the condition of using single distributed optical fiber vibration sensing principle, the time interval of sending laser pulses is related to the length of the accessed optical fiber (after each pulse is sent, it is necessary to ensure that all length optical scattering light has returned before the next optical pulse is output), therefore, the frequency response range of the single distributed optical fiber sensing method becomes lower with the increase of distance, and there is a problem of limited bandwidth. When using an electrical hydrophone array method for leakage monitoring, all hydrophones need to be synchronously collected (the time synchronization accuracy cannot exceed 1 ms), and since the pipeline is underground, especially in the case of tunnel, the distance between two pipeline wells is very long (>1.5 km), and the monitoring distance of adjacent hydrophones cannot be fully covered, therefore, it is necessary to install electrical hydrophones at positions without pipeline wells, at this time, power supply and synchronization become difficult problems because the Beidou terminal antenna for synchronization cannot be stretched to the ground. The single electrical hydrophone array needs to be precisely synchronized by external Beidou for time service to carry out related analysis, and in long-distance pipeline construction, the solar power supply required by each group of electrical hydrophone arrays every few hundred meters is also a difficult problem.

[0005] In summary, existing single distributed fiber optic sensing methods suffer from bandwidth limitations, and single electro-hydrophone array methods face challenges in clock synchronization and power supply in the field. These factors restrict the widespread adoption of water monitoring systems. Utility Model Content

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a water pipeline safety monitoring system based on fiber optic vibration and underwater acoustic sensing. It integrates φ-OTDR and interferometric hydrophone technology, which has both precise positioning capabilities through distributed optical fibers and broadband underwater acoustic listening capabilities. Furthermore, due to the all-optical approach, no power supply is required along the entire pipeline, and it is unaffected by environmental interference. In addition, acoustic verification and other methods are fully applied during data analysis to solve the problem of leak detection and location in water pipelines.

[0007] The purpose of this utility model is achieved through the following technical solution: a safety monitoring system for water pipelines based on fiber optic vibration and underwater acoustic sensing, comprising:

[0008] The distributed fiber optic acoustic vibration monitoring subsystem includes a distributed fiber optic acoustic vibration demodulation device and distributed optical fibers, with the optical cables tightly installed on the outer wall of the pipe.

[0009] An interferometric quasi-distributed fiber optic hydrophone subsystem includes an interferometric quasi-distributed fiber optic hydrophone demodulation device, a fiber optic hydrophone, and an interferometric fiber. There are several fiber optic hydrophones, which are spaced apart on the outer wall of the pipe. Each fiber optic hydrophone is fixed to the outer wall of the pipe through a rigid shell, and the interferometric fiber passes through each rigid shell in sequence.

[0010] The signal fusion analysis subsystem, mounted on a computer with computing power, is used to simultaneously receive data from the interferometric quasi-distributed fiber optic hydrophone demodulation device and the distributed fiber optic acoustic vibration demodulation device, align and store the data, and perform analysis and identification.

[0011] The pipeline safety monitoring platform software, installed on the computer, is used to receive data analyzed and identified by the signal fusion analysis subsystem, perform visualization processing, and display the safety status of various locations on the pipeline in real time based on the data; and

[0012] The synchronization time device synchronizes the distributed fiber optic acoustic vibration monitoring subsystem and the interferometric quasi-distributed fiber optic hydrophone subsystem using a standard clock source.

[0013] As a further technical solution, the interferometric quasi-distributed fiber optic hydrophone demodulation device uses time-division multiplexing to collect signals transmitted from multiple fiber optic hydrophones. The distributed acoustic vibration demodulation device uses phase-sensitive optical reflectometer technology. Both the distributed fiber optic acoustic vibration demodulation device and the interferometric quasi-distributed fiber optic hydrophone demodulation device are equipped with a synchronization signal input interface, which is used to synchronize the sampling signal inside the demodulation device. The distributed fiber optic acoustic vibration demodulation device has a dual-channel synchronous output capability, which is used to simultaneously connect to two optical fibers and simultaneously collect vibration signals on the two optical fibers.

[0014] As a further technical solution, the fiber optic hydrophone includes a fiber optic vibration sensing component, a fiber optic coil, a reflector, and a flexible acoustic sensing component disposed within a rigid housing. The fiber optic hydrophone is connected in series in a time-division manner to form a multi-sensor vibration signal measurement, and the fiber optic hydrophone is positioned using an OTDR method. The rigid housing of the fiber optic hydrophone has a fiber coiling space for coiling the spliced ​​excess fiber length within the rigid housing. The distributed optical fiber and the interferometric optical fiber are integrated on a single optical cable.

[0015] As a further technical solution, the fiber optic vibration sensing component includes a mechanical resonator and a fiber optic coil tightly fixed to the mechanical resonator. The rigid housing adopts a dual-outlet fiber optic interface, with one end connected to the input light and the other end connected to the output light, which can be cascaded to the next fiber optic hydrophone. The fiber optic outlet of the rigid housing is sealed with adhesive to prevent external pulling of the fiber optic cable from affecting the inside of the fiber optic hydrophone. A vibration damping area is provided between the fiber optic coil and the fiber optic outlet to prevent vibration of the connecting fiber optic cable from affecting the internal sensor. The sensing surface of the flexible acoustic sensing component exists only on the side attached to the pipe wall, and it only responds to vibration / sound wave information from the pipe wall, and is not affected by sound from other directions.

[0016] As a further technical solution, the signal fusion analysis subsystem also includes:

[0017] The network interface is used to simultaneously receive data from both the interferometric quasi-distributed fiber optic hydrophone demodulation device and the distributed fiber optic acoustic vibration demodulation device.

[0018] The data synchronization and storage module is used to align and store data from the interferometric quasi-distributed fiber optic hydrophone demodulation device and the distributed fiber optic acoustic vibration demodulation device at the same time.

[0019] The hydrophone signal recognition module analyzes and identifies data from the interferometric quasi-distributed fiber optic hydrophone demodulation device, providing the sound event identification type and the specific hydrophone where the event occurred; and

[0020] The distributed optical fiber signal identification module is used to analyze and identify data from the distributed optical fiber acoustic wave vibration demodulation device, and to provide the sound event identification type and the distance of the specific event relative to the optical fiber outlet of the distributed optical fiber acoustic wave demodulation device.

[0021] The beneficial effects of this utility model are as follows:

[0022] 1. This utility model adopts a distributed optical fiber combined with an optical fiber hydrophone. It utilizes the high bandwidth of the optical fiber hydrophone to make up for the insufficient bandwidth of the distributed optical fiber, uses the sensing optical cable of the distributed optical fiber as the transmission optical cable between the optical fiber hydrophones, and takes advantage of the fast optical transmission speed and natural synchronization of the optical fiber hydrophone. This forms a continuous monitoring system with no blind spots, broadband sound source information input, dual-technology composite judgment, low false alarm rate, and high reliability.

[0023] 2. This utility model combines distributed optical fiber vibration sensing (φ-OTDR principle) with a quasi-distributed interferometric optical fiber hydrophone array to jointly detect sound in pipelines. It also performs spatiotemporal synchronization of the optical cable signal attached to the pipe wall (for distributed optical fiber vibration sensing) and the optical fiber hydrophone signal (for quasi-distributed array sensing). This effectively solves the shortcomings of traditional single distributed optical fiber vibration sensing (limited bandwidth of distributed optical fiber vibration sensing under long-distance conditions) or single hydrophone monitoring (poor positioning accuracy), greatly improving the efficiency and accuracy of pipeline leak monitoring. Attached Figure Description

[0024] Fig. 1 This is a schematic diagram of the structure of this utility model.

[0025] Fig. 2 This is a flowchart illustrating the present invention.

[0026] Fig. 3 This is a schematic diagram of the assembly of the pipe and the fiber optic hydrophone of this utility model.

[0027] Explanation of reference numerals in the attached drawings: 1. Pipeline; 2. Rigid outer shell; 3. Fiber optic space; 4. Fiber optic vibration sensing component; 5. Fiber optic cable; 6. Vibration reduction area; 7. Distributed fiber optic acoustic vibration monitoring subsystem; 10. Interferometric quasi-distributed fiber optic hydrophone subsystem; 20. Signal fusion analysis subsystem; 30. Pipeline safety monitoring platform software; 40. Synchronization time synchronization device; 50. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings:

[0029] Example 1: As shown in the attached document Figs. 1-3As shown, a water pipeline safety monitoring system based on fiber optic vibration and underwater acoustic sensing includes a pipeline 1, a rigid shell 2, a fiber optic coil space 3, a fiber optic vibration sensing component 4, a flexible acoustic sensing component 5, an optical cable 6, a vibration reduction area 7, a distributed fiber optic acoustic vibration monitoring subsystem 10, an interferometric quasi-distributed fiber optic hydrophone subsystem 20, a signal fusion analysis subsystem 30, pipeline safety monitoring platform software 40, and a synchronization time synchronization device 50.

[0030] Reference Appendix Fig. 1 , 3 The distributed fiber optic acoustic vibration monitoring subsystem 10 includes a distributed fiber optic acoustic vibration demodulation device and distributed optical fibers. The distributed optical fibers are tightly installed on the outer wall of a pipe 1 (which can be a ductile iron pipe, steel pipe, or other metal pipe). The distributed acoustic vibration demodulation device employs phase-sensitive optical reflectometer technology. Furthermore, the distributed fiber optic acoustic vibration demodulation device includes a narrow-linewidth laser, an optical fiber beam splitter, an acousto-optic modulator, a pulsed erbium-doped fiber amplifier (pulsed EDFA), an optical fiber circulator, a Raman-pumped laser, an optical fiber wavelength division multiplexer, a polarization classification module, an optical fiber coupler, and a photoelectric converter.

[0031] The interferometric quasi-distributed fiber optic hydrophone subsystem 20 includes an interferometric quasi-distributed fiber optic hydrophone demodulation device, fiber optic hydrophones, and interferometric optical fibers. Several fiber optic hydrophones are spaced apart on the outer wall of the pipe 1. Each fiber optic hydrophone is fixed to the outer wall of the pipe 1 via a rigid housing 2. The interferometric optical fibers sequentially pass through each rigid housing 2. Fig. 3 As shown, the fiber optic hydrophone includes a fiber optic vibration sensing component 4, a fiber optic coil, a reflector, and a flexible acoustic sensing component 5, all housed within a rigid housing 2. The fiber optic hydrophones are connected in series using a time-division multiplexing method to form a multi-sensor vibration signal measurement system, and the fiber optic hydrophone uses an OTDR (Optical Time-of-Depth) method for positioning. The rigid housing 2 of the fiber optic hydrophone has a fiber coiling space 3, which can be used to coil the spliced ​​excess fiber length within the rigid housing 2. Preferably, the distributed fiber and the interferometric fiber can be integrated onto a single optical cable 6 (so that the sensing cable of the distributed fiber acts as the transmission cable between the fiber optic hydrophones, resulting in higher integration and reduced manufacturing costs), or the distributed fiber and the interferometric fiber can be placed on different optical cables.

[0032] The interferometric quasi-distributed fiber optic hydrophone demodulation device uses time-division multiplexing to collect signals from multiple fiber optic hydrophones, achieving multiplexing with fewer optical fibers. Furthermore, both the distributed fiber optic acoustic vibration demodulation device and the interferometric quasi-distributed fiber optic hydrophone demodulation device are equipped with a synchronization signal input interface. This synchronization signal can synchronize the sampling signals inside the demodulation device; it can be a BeiDou PPS signal or a synchronization signal transmitted from other systems. The distributed fiber optic acoustic vibration demodulation device has dual-channel synchronous output capability, allowing simultaneous access to two optical fibers and simultaneous acquisition of vibration signals from both fibers. Further, the interferometric quasi-distributed fiber optic hydrophone demodulation device includes a narrow-linewidth laser, an optical fiber beam splitter, a pulsed erbium-doped fiber amplifier (pulse EDFA), a photoelectric converter, a signal amplification module, a signal generation module, a signal demodulation module, and an optical fiber coupler.

[0033] like Fig. 3 As shown, the fiber optic vibration sensing component 4 includes a mechanical resonator and a fiber optic coil tightly fixed to the mechanical resonator. The rigid housing 2 adopts a dual-outlet fiber optic interface, with one end connected to the input light and the other end connected to the output light, which can be cascaded to the next fiber optic hydrophone. The fiber optic outlet of the rigid housing 2 is sealed with adhesive to prevent external pulling of the fiber optic cable from affecting the internal structure of the fiber optic hydrophone. A vibration damping area 7 is provided between the fiber optic coil and the fiber optic outlet to prevent vibration of the connecting fiber optic cable from affecting the internal sensor. The sensing surface of the flexible acoustic sensing component 5 exists only on the side attached to the wall of the pipe 1, and it only responds to vibration / sound wave information from the wall of the pipe 1, and is not affected by sound from other directions.

[0034] The signal fusion analysis subsystem 30 (including signal fusion analysis algorithm software, mounted / installed on a computer with computing power, including but not limited to industrial control computers, servers, or other devices with computing power) is capable of simultaneously receiving data from an interferometric quasi-distributed fiber optic hydrophone demodulation device and a distributed fiber optic acoustic vibration demodulation device, aligning and storing the data, and performing analysis and identification. Furthermore, the signal fusion analysis subsystem 30 also includes:

[0035] The network interface is capable of simultaneously receiving data from both the interferometric quasi-distributed fiber optic hydrophone demodulation device and the distributed fiber optic acoustic vibration demodulation device.

[0036] The data synchronization and storage module can synchronize and store data from the interferometric quasi-distributed fiber optic hydrophone demodulation device and the distributed fiber optic acoustic vibration demodulation device at the same time.

[0037] The hydrophone signal recognition module can analyze and identify data from the interferometric quasi-distributed fiber optic hydrophone demodulation device, providing the sound event identification type and the specific hydrophone where the event occurred; and

[0038] The distributed optical fiber signal recognition module can analyze and identify data from the distributed optical fiber acoustic wave vibration demodulation device, and provide the sound event recognition type and the distance of the specific event relative to the optical fiber outlet of the distributed optical fiber acoustic wave demodulation device.

[0039] Furthermore, the pipeline safety monitoring platform software 40 is also mounted on a computer, capable of receiving data analyzed and identified by the signal fusion analysis subsystem 30, and performing visualization processing to display the safety status of various locations on pipeline 1 in real time based on the data. This pipeline safety monitoring platform software includes interfaces for pipeline layout GIS, pipeline route marking, pipeline well marking, pipeline leakage alarm, pipeline vibration alarm, equipment management, fiber optic vibration time-domain signal, fiber optic vibration frequency-domain signal, hydrophone vibration time-domain signal, hydrophone vibration frequency-domain signal, and signal spatiotemporal synchronization composite.

[0040] The synchronization time device 50 synchronizes the distributed fiber optic acoustic vibration monitoring subsystem 10 and the interferometric quasi-distributed fiber optic hydrophone subsystem 20 through a standard clock source (using Beidou time synchronization or other standard clock sources), and also has network time synchronization function.

[0041] Example 2: A method for safety monitoring of water pipelines based on fiber optic vibration and underwater acoustic sensing, based on the safety monitoring system for water pipelines based on fiber optic vibration and underwater acoustic sensing described in Example 1, includes the following steps:

[0042] S1: Perform distributed optical fiber distance calibration on pipe 1 to obtain the spatial distribution of vibration along the entire line with pipe 1 as the horizontal axis and spatial sampling rate at intervals.

[0043] Furthermore, the above-mentioned S1 also includes:

[0044] S1.1 Attach a vibrating optical cable to each side of the pipe 1, and connect one core of each of the two vibrating optical cables to the optical fiber interface of the optical fiber vibration sensing component 4.

[0045] S1.2. Use a standard distance measuring device such as a ruler or laser rangefinder to measure a distance, and gently tap the vibrating optical cable at that point. Map the optical fiber length displayed on the time domain signal of the optical fiber vibration on the pipeline safety monitoring platform software 40 at this time to the actual pipeline distance.

[0046] S1.3 Complete the distance calibration of the two vibrating optical cables to obtain the spatial distribution of vibration along the entire line with pipe 1 as the horizontal axis and the spatial sampling rate as the interval.

[0047] S2: Measure the fiber optic hydrophone deployment intervals on pipe 1 to obtain the spatial distribution of multi-point vibration along the entire line with pipe 1 as the horizontal axis and the distance between fiber optic hydrophones as the intervals.

[0048] The above S2 also includes:

[0049] S2.1 Use an OTDR to measure the actual location and fiber length of each fiber hydrophone.

[0050] S2.2 Connect the fiber optic hydrophone to the interferometric quasi-distributed fiber optic hydrophone demodulation device, and adjust the time interval of the time division multiplexing to ensure that the fiber optic hydrophone signal acquisition is in the optimal position.

[0051] S2.3. Use standard distance measuring devices such as a meter stick and laser rangefinder to measure the distance of the hydrophone on the pipeline, and map the fiber optic hydrophone number to the actual pipeline distance.

[0052] S2.4 Complete the distance calibration of all fiber optic hydrophones to obtain the spatial distribution of multi-point vibration along the entire line with pipe 1 as the horizontal axis and the distance between the fiber optic hydrophones as the interval.

[0053] S3: Sample library establishment and identification, collecting sound data under different conditions and events, establishing a sample library, and forming alarm strategies under different events.

[0054] Specifically, S3 also includes:

[0055] S3.1 Collect sound data under quiet conditions (when the fan in the duct is off), mark it and store it in the negative sample library.

[0056] S3.2 Collect sound data from non-quiet conditions or uncertain interference sources (such as rain), mark them, and store them in the negative sample library.

[0057] S3.3 Collect sound data of known interference events (such as ventilation fan sound, pile driving sound above, subway passing sound), classify and label them and store them in the positive sample library.

[0058] S3.4 Collect sound data of known simulated leakage events (such as dripping water in pipes, sound of water scouring pipes), classify and label them, and store them in the positive sample library.

[0059] S3.5. Establish a sample library and train it using a convolutional neural network (CNN).

[0060] S3.6 Collect the correct data and perform event recognition.

[0061] S3.7. An alarm strategy is formed based on the identified events. If the event is a short-term large signal event (such as a knock), it is reported in time. If the event is a continuous small signal event (such as a small leak), it is reported after multiple judgments.

[0062] S4: Demodulate using a distributed fiber optic acoustic vibration demodulation device and an interferometric quasi-distributed fiber optic hydrophone demodulation device to obtain three-dimensional information of vibration amplitude, time, and distance. Determine whether an event has occurred, locate the actual location of the event, compare and judge with the sample database, record and store the obtained event type, and issue an alarm signal.

[0063] The above-mentioned S4 also includes:

[0064] S4.1 After completing the distributed fiber optic distance calibration and fiber optic hydrophone deployment interval measurement calibration, start the system to enter normal working mode.

[0065] S4.2 The distributed optical fiber acoustic vibration demodulation device obtains three-dimensional information of vibration amplitude A1(t,d)-time-distance by performing phase demodulation on the scattered signal returned from the distributed sensing optical fiber.

[0066] S4.3 The interferometric quasi-distributed fiber optic hydrophone demodulation device demodulates the interferometric signal returned from the fiber optic hydrophone to obtain three-dimensional information of vibration amplitude A2(t,d)-time-distance.

[0067] S4.4. Perform data cleaning on the vibration amplitude A1(t,d)-time-distance three-dimensional information to obtain the vibration amplitude B1(t,d)-time-distance three-dimensional information, and perform data cleaning on the vibration amplitude A2(t,d)-time-distance three-dimensional information to obtain the vibration amplitude B2(t,d)-time-distance three-dimensional information.

[0068] S4.5. Compare the energy change between the vibration amplitude B1(t,d)-time-distance and its body noise to determine whether an event has occurred and identify it, and obtain E1(t1,d1).

[0069] S4.6. Compare the relationship between the vibration amplitude B2(t,d)-time-distance and its own noise to determine whether an event has occurred; and perform correlation analysis on the two adjacent fiber optic hydrophones at the event location to locate the actual event location E2(t2,d2).

[0070] S4.7 Determine whether |t1-t2| is less than a certain range and |d1-d2| is also less than a certain range. If so, it is considered to be caused by the same event, and the review is passed.

[0071] S4.8. Use machine learning methods to compare the data with the sample library to determine the event type.

[0072] S4.9 Record and store the time, location, and event type of the event.

[0073] This invention combines distributed fiber optic vibration sensing (φ-OTDR principle) with a quasi-distributed interferometric fiber optic hydrophone array to jointly detect sound in pipelines. It also performs spatiotemporal synchronization of the optical cable signal attached to the pipe wall (for distributed fiber optic vibration sensing) and the fiber optic hydrophone signal (for quasi-distributed array sensing). This effectively solves the shortcomings of traditional single distributed fiber optic vibration sensing (limited bandwidth of distributed fiber optic vibration sensing under long-distance conditions) or single hydrophone monitoring (poor positioning accuracy), greatly improving the efficiency and accuracy of pipeline leak monitoring.

[0074] The technology principle of this utility model is similar to that of monitoring PCCP wire breakage using distributed optical fiber acoustic sensing combined with interferometric optical fiber sensors, and their basic optical interference principles are similar.

[0075] However, the difference is:

[0076] 1. This utility model is an interferometric hydrophone in which the sensing optical fiber is made into a point vibration sensing device with a unique vibration structure (while in PCCP wire breakage monitoring, it is still a whole sensing optical cable).

[0077] 2. The interferometric hydrophone in this utility model adopts a time-division multiplexing method, with multiple hydrophones forming an array, and leakage location identification is performed through related methods (while PCCP wire breakage monitoring cannot be located through related methods).

[0078] 3. In the signal fusion analysis of this utility model, the distributed optical fiber acoustic vibration monitoring subsystem and the interferometric quasi-distributed optical fiber hydrophone subsystem are strictly synchronized in time and space (while PCCP wire breakage monitoring is mainly time synchronized).

[0079] It is understood that, for those skilled in the art, any equivalent substitutions or modifications to the technical solutions and inventive concepts of this utility model should fall within the protection scope of the appended claims.

Claims

1. A safety monitoring system for water pipelines based on fiber optic vibration and underwater acoustic sensing, characterized in that, include: The distributed optical fiber acoustic vibration monitoring subsystem (10) includes a distributed optical fiber acoustic vibration demodulation device and a distributed optical fiber, wherein the distributed optical fiber is tightly installed on the outer wall of the pipe (1). The interferometric quasi-distributed fiber optic hydrophone subsystem (20) includes an interferometric quasi-distributed fiber optic hydrophone demodulation device, a fiber optic hydrophone and an interferometric fiber. There are several fiber optic hydrophones, which are arranged at intervals on the outer wall of the pipe (1). Each fiber optic hydrophone is fixed to the outer wall of the pipe (1) through a rigid shell (2). The interferometric fiber passes through each rigid shell (2) in sequence. The signal fusion analysis subsystem (30) is mounted on a computer with computing power and is used to simultaneously receive data from the interferometric quasi-distributed fiber optic hydrophone demodulation device and the distributed fiber optic acoustic vibration demodulation device, and to align, store, analyze and identify the data. The pipeline safety monitoring platform software (40) is mounted on the computer and is used to receive data after analysis and identification by the signal fusion analysis subsystem (30), and to perform visualization processing. Based on the data, the safety status of each location on the pipeline (1) is displayed in real time. as well as The synchronization timing device (50) synchronizes the distributed fiber optic acoustic vibration monitoring subsystem (10) and the interferometric quasi-distributed fiber optic hydrophone subsystem (20) through a standard clock source.

2. The water pipeline safety monitoring system based on fiber optic vibration and underwater acoustic sensing according to claim 1, characterized in that: The interferometric quasi-distributed fiber optic hydrophone demodulation device uses time-division multiplexing to collect signals transmitted from multiple fiber optic hydrophones, and the distributed acoustic vibration demodulation device uses phase-sensitive optical reflector technology. Both the distributed optical fiber acoustic vibration demodulation device and the interferometric quasi-distributed optical fiber hydrophone demodulation device are equipped with a synchronization signal input interface, which is used to synchronize the sampling signal inside the demodulation device. The distributed optical fiber acoustic vibration demodulation device has a dual-channel synchronous output capability, which is used to simultaneously connect to two optical fibers and simultaneously collect vibration signals on the two optical fibers.

3. The water pipeline safety monitoring system based on fiber optic vibration and underwater acoustic sensing according to claim 1, characterized in that: The fiber optic hydrophone includes a fiber optic vibration sensing component (4), a fiber optic coil, a reflector, and a flexible acoustic sensing component (5) disposed within a rigid housing (2). The fiber optic hydrophone is connected in series in a time-division manner to form a multi-sensor vibration signal measurement, and the fiber optic hydrophone is positioned using an OTDR method. The rigid housing (2) of the fiber optic hydrophone is provided with a fiber coiling space (3) for coiling the spliced ​​fiber excess length within the rigid housing (2). The distributed optical fiber and the interferometric optical fiber are integrated on a single optical cable (6).

4. The water pipeline safety monitoring system based on fiber optic vibration and underwater acoustic sensing according to claim 3, characterized in that: The fiber optic vibration sensing component (4) includes a mechanical resonant component and a fiber optic coil tightly fixed to the mechanical resonant component. The rigid housing (2) adopts a fiber optic dual-outlet interface, with one end connected to the input light and the other end connected to the output light, which can be cascaded to the next fiber optic hydrophone. The fiber optic outlet of the rigid housing (2) is sealed with adhesive. A vibration damping area (7) is provided between the fiber optic coil and the fiber optic outlet. The sensing surface of the flexible acoustic sensing component (5) exists only on the side attached to the wall of the pipe (1), and only responds to vibration / sound wave information from the wall of the pipe (1), and is not affected by sound from other directions.

5. The water pipeline safety monitoring system based on fiber optic vibration and underwater acoustic sensing according to claim 1, characterized in that: The signal fusion analysis subsystem (30) also includes: The network interface is used to simultaneously receive data from both the interferometric quasi-distributed fiber optic hydrophone demodulation device and the distributed fiber optic acoustic vibration demodulation device. The data synchronization and storage module is used to align and store data from the interferometric quasi-distributed fiber optic hydrophone demodulation device and the distributed fiber optic acoustic vibration demodulation device at the same time. The hydrophone signal recognition module analyzes and identifies data from the interferometric quasi-distributed fiber optic hydrophone demodulation device, providing the sound event identification type and the specific hydrophone where the event occurred; and The distributed optical fiber signal identification module is used to analyze and identify data from the distributed optical fiber acoustic wave vibration demodulation device, and to provide the sound event identification type and the distance of the specific event relative to the optical fiber outlet of the distributed optical fiber acoustic wave demodulation device.

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