CN114440141A

CN114440141A - Pipeline leakage detection method and system

Info

Publication number: CN114440141A
Application number: CN202011191138.6A
Authority: CN
Inventors: 王洪超; 张栋; 孟佳; 张洪; 吴琼; 马云宾; 蔡永军; 王立坤; 吴家勇; 王乐乐
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2020-10-30
Filing date: 2020-10-30
Publication date: 2022-05-06
Anticipated expiration: 2040-10-30
Also published as: CN114440141B

Abstract

The application discloses a pipeline leakage detection method and system, and belongs to the field of oil and gas storage and transportation. This pipeline leak detection system includes: the system comprises a first photoelectric acquisition subsystem, a second photoelectric acquisition subsystem, a sound wave acquisition subsystem and a leakage detection subsystem. The first photoelectric acquisition subsystem can acquire a first electric signal for reflecting the sound vibration law, the second photoelectric acquisition subsystem can acquire a second electric signal for reflecting the temperature, and the sound wave acquisition subsystem can acquire a third electric signal for reflecting the sound vibration law. Therefore, the leakage detection subsystem can detect whether the pipeline leaks according to the three types of electric signals, and the reliability of pipeline leakage detection is effectively improved.

Description

Pipeline leakage detection method and system

Technical Field

The application relates to the field of oil and gas storage and transportation, in particular to a pipeline leakage detection method and system.

Background

Pipeline transportation is the primary means of transportation for oil and gas products. Leakage is a main factor influencing the safety of oil and gas pipelines, and pipeline leakage can be caused by corrosion perforation, sudden natural disasters, artificial damage and the like of the pipelines. Once the oil and gas pipeline leaks, major safety accidents are easily caused, so that the real-time detection of the leakage of the oil and gas pipeline is very important.

In the related art, because the leakage sound wave is generated due to the leakage of the oil and gas pipeline, a sound wave sensor can be generally arranged on the pipeline, and the leakage sound wave is detected through the sound wave sensor, so that the detection of the pipeline leakage can be realized.

However, since the attenuation of the sound wave propagating through the pipe is large, if the distance between the sound wave sensors is long, a small leakage sound wave cannot be effectively detected, and the accuracy of the leakage detection is low.

Disclosure of Invention

The application provides a pipeline leakage detection method and system, which can solve the problem of low precision of pipeline leakage detection in the related technology. The technical scheme is as follows:

in one aspect, a pipe leak detection system is provided, the system comprising: the system comprises a first photoelectric acquisition subsystem, a second photoelectric acquisition subsystem, a sound wave acquisition subsystem and a leakage detection subsystem;

the first optoelectronic collection subsystem comprises: the system comprises a first laser, a first pipeline accompanying optical cable and a first signal processing assembly, wherein the first laser is used for emitting first laser to the first pipeline accompanying optical cable, the first signal processing assembly is used for converting a first scattered light signal generated in the first pipeline accompanying optical cable by the first laser into a first electric signal and transmitting the first electric signal to the leakage detection subsystem, and the first scattered light signal is generated by sound vibration;

the second optoelectronic collection subsystem comprises: the second laser is used for emitting second laser to the second pipeline accompanying optical cable, and the second signal processing component is used for generating a second electric signal according to a second scattered light signal generated in the second pipeline accompanying optical cable by the second laser and transmitting the second electric signal to the leakage detection subsystem, wherein the second scattered light signal is generated by temperature change;

the sound wave collection subsystem includes: the multiple sound wave sensors are arranged on the pipeline at intervals and used for transmitting collected sound wave signals to the third signal processing assembly, and the third signal processing assembly is used for processing the sound wave signals to obtain third electric signals and transmitting the third electric signals to the leakage detection subsystem;

and the leakage detection subsystem is used for determining a sound vibration rule around the pipeline according to the first electric signal and the third electric signal, detecting whether the pipeline leaks or not according to the sound vibration rule, determining the temperature change condition around the pipeline according to the second electric signal, and detecting whether the pipeline leaks or not according to the temperature change condition.

Optionally, the first signal processing component includes: a first Circulator (CIR), a first amplifier, a first filter, a first photodetector, and a first analog-to-digital converter;

wherein the first circulator is respectively connected with the first laser, the first pipeline accompanying optical cable and the first amplifier, and is used for transmitting the first laser to the first pipeline accompanying optical cable and transmitting a first scattered light signal generated in the first pipeline accompanying optical cable to the first amplifier;

the first amplifier is also connected with the first filter and is used for amplifying the first scattered light signal transmitted by the first circulator and transmitting the amplified first scattered light signal to the first filter;

the first filter is further connected with the first photodetector, and is configured to filter the first scattered light signal transmitted by the first amplifier and transmit the filtered first scattered light signal to the first photodetector;

the first photodetector is further connected to the first analog-to-digital converter, and is configured to convert the filtered first scattered light signal transmitted by the first filter into an analog first electrical signal, and transmit the analog first electrical signal to the first analog-to-digital converter;

the first analog-to-digital converter is further connected to the leak detection subsystem for converting the analog first electrical signal to a digital first electrical signal and transmitting the digital first electrical signal to the leak detection subsystem.

Optionally, the first signal processing component further includes: a first acousto-optic modulator (AOM) and a second amplifier connected in series between the first laser and the first circulator;

the first acousto-optic modulator is used for acousto-optic modulating first laser emitted by the first laser and transmitting the acousto-optic modulated first laser to the second amplifier;

and the second amplifier is used for amplifying the first laser transmitted by the first acousto-optic modulator and then transmitting the amplified first laser to the first circulator.

Optionally, the second pipe-accompanying optical cable includes a first optical fiber segment and a second optical fiber segment; the second signal processing assembly includes: a beam splitter, a second acoustic-optical modulator, an electro-optical modulator (EOM), a second filter, a second circulator, a second photodetector, and a second analog-to-digital converter;

the beam splitter is respectively connected with the second laser, the second acoustic optical modulator and the electro-optical modulator and is used for splitting the second laser beam and respectively transmitting the split beam to the second acoustic optical modulator and the electro-optical modulator;

the second acousto-optic modulator is connected with the second circulator and is used for acousto-optic modulating a laser beam transmitted by the beam splitter and transmitting the acousto-optic modulated laser beam to the second circulator;

the electro-optical modulator is also connected with the second filter and is used for electro-optically modulating the other laser beam transmitted by the beam splitter and transmitting the laser beam after the electro-optical modulation to the second circulator;

the second filter is also connected with one end of the first optical fiber section and is used for filtering the laser transmitted by the electro-optical modulator and transmitting the filtered laser to the first optical fiber section;

the second circulator is also respectively connected with one end of the second optical fiber segment and the second photodetector, and is used for transmitting the laser light transmitted by the second acousto-optic modulator to the second optical fiber segment and transmitting a second scattered light signal transmitted by the second optical fiber segment to the second photodetector, wherein the other end of the first optical fiber segment is connected with the other end of the second optical fiber segment;

the second photodetector is further connected to the second analog-to-digital converter, and is configured to convert the optical signal transmitted by the second circulator into an analog second electrical signal, and transmit the analog second electrical signal to the second analog-to-digital converter;

the second analog-to-digital converter is further coupled to the leak detection subsystem for converting the analog second electrical signal to a digital second electrical signal and transmitting the digital second electrical signal to the leak detection subsystem.

Optionally, the third signal processing component includes: a third analog-to-digital converter, a plurality of third amplifiers, and a plurality of third filters;

each third filter is respectively connected with one sound wave sensor and one third amplifier and is used for filtering the sound wave signals transmitted by the sound wave sensors and then sending the sound wave signals to the third amplifiers;

each third amplifier is connected with the third analog-to-digital converter and is used for amplifying the filtered sound wave signal transmitted by the third filter and transmitting the amplified sound wave signal to the third analog-to-digital converter;

the third analog-to-digital converter is further connected to the leakage subsystem, and is configured to convert the amplified acoustic wave signal transmitted by each third amplifier into a third electrical signal, and transmit the third electrical signal to the leakage detection subsystem.

Optionally, the sound wave collecting subsystem further includes: a solar cell and a wireless communication assembly;

the solar cell is respectively connected with the plurality of acoustic wave sensors, the third signal processing assembly and the wireless communication assembly and used for supplying power to the plurality of acoustic wave sensors, the third signal processing assembly and the wireless communication assembly;

the wireless communication assembly is respectively connected with the third signal processing assembly and the leakage sub-system, and is used for transmitting the third electric signal to the leakage sub-system.

Optionally, the third signal processing component further includes: a sample holder, a multi-way switch;

the sampling retainer is respectively connected with the plurality of third amplifiers and the multi-way switch and is used for sampling the sound wave signals transmitted by each third amplifier and transmitting the sampled multi-way sound wave signals to the multi-way switch;

the multi-way switch is also connected with the analog-to-digital converter and used for transmitting the received multi-way sampled sound wave signals to the analog-to-digital converter one by one.

Optionally, the leakage sub-system includes: the communication component, the fourth signal processing component and the alarm component are arranged on the base;

the communication assembly is respectively connected with a fourth signal processing assembly and an alarm assembly and is used for receiving the first electric signal, the second electric signal and the third electric signal and transmitting the first electric signal, the second electric signal and the third electric signal to the fourth signal processing assembly;

the fourth signal processing component is used for determining a sound vibration rule around the pipeline according to the first electric signal and the third electric signal, detecting whether the pipeline leaks or not according to the sound vibration rule, determining a temperature change condition around the pipeline according to the second electric signal, and detecting whether the pipeline leaks or not according to the temperature change condition;

the fourth signal processing component is further used for determining a leakage position and sending an alarm instruction to the alarm component when the leakage of the pipeline is determined according to any electric signal;

the alarm component is used for responding to the alarm instruction and generating an alarm signal.

Optionally, the fourth signal processing component is configured to:

inputting the first electric signal to a nonlinear system to obtain a first phase track;

inputting the third electric signal to a nonlinear system to obtain a second phase track;

if any one of the first phase trajectory and the second phase trajectory is a periodic trajectory, determining that the pipeline has leakage;

and if the temperature around the pipeline is determined to be reduced according to the second electric signal, and the difference value between the minimum value of the temperature variation and the average value of the temperature variation is larger than the temperature threshold value, determining that the pipeline has leakage.

In another aspect, a method for detecting a pipeline leakage is provided, which is applied to a leakage detection subsystem, and includes:

receiving a first electric signal sent by a first photoelectric acquisition subsystem, wherein the first electric signal is obtained by converting a first scattered light signal generated in a first pipeline accompanying optical cable and is generated by sound vibration;

receiving a second electric signal sent by a second photoelectric acquisition subsystem, wherein the second electric signal is generated according to a second scattered light signal generated in a second pipeline accompanying optical cable and generated by temperature change;

receiving a third electric signal sent by the sound wave acquisition subsystem, wherein the third electric signal is obtained by processing the sound wave signal acquired by the sound wave sensor;

determining a sound vibration rule around the pipeline according to the first electric signal and the third electric signal, and detecting whether the pipeline leaks or not according to the sound vibration rule;

and determining the temperature change condition around the pipeline according to the second electric signal, and detecting whether the pipeline leaks or not according to the temperature change condition.

The beneficial effects that technical scheme that this application provided brought can include at least:

the embodiment of the application provides a pipeline leakage detection method and system, the system can collect a first electric signal for reflecting a sound vibration rule through a first photoelectric collection subsystem, collect a second electric signal for reflecting a temperature through a second photoelectric collection subsystem, and collect a third electric signal for reflecting the sound vibration rule through a sound wave collection subsystem. Therefore, the leakage detection subsystem can detect whether the pipeline leaks according to the three types of electric signals, and the reliability of pipeline leakage detection is effectively improved. In addition, the first photoelectric acquisition system and the second photoelectric acquisition system adopt the pipeline accompanying optical cables, so that long-distance detection of the pipeline can be realized, and the range of leakage detection is effectively enlarged. And because the detection precision of the sound wave detection subsystem is higher, the sound wave acquisition subsystem can be deployed in a high-consequence area to ensure the accurate detection of the pipeline leakage of the high-consequence area.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a pipeline leakage detection system provided in an embodiment of the present application;

fig. 2 is a schematic structural diagram of a first photoelectric acquisition subsystem and a second photoelectric acquisition subsystem provided in an embodiment of the present application;

fig. 3 is a schematic structural diagram of an acoustic wave collection subsystem provided in an embodiment of the present application;

FIG. 4 is a schematic structural diagram of a leakage sub-system provided by an embodiment of the present application;

FIG. 5 is a schematic diagram of a phase trajectory of a large scale periodic state provided by an embodiment of the present application;

FIG. 6 is a schematic diagram of a phase trajectory of a chaotic state according to an embodiment of the present disclosure;

FIG. 7 is a flow chart of a method for detecting and analyzing electrical signals according to an embodiment of the present disclosure;

FIG. 8 is a flow chart of another method for detecting and analyzing electrical signals provided by embodiments of the present application;

fig. 9 is a flowchart of a method for detecting a pipeline leakage according to an embodiment of the present application.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

An embodiment of the present application provides a pipe leakage detecting system, as shown in fig. 1, the pipe leakage detecting system may include: the system comprises a first photoelectric acquisition subsystem 01, a second photoelectric acquisition subsystem 02, an acoustic wave acquisition subsystem 03 and a leakage detection subsystem 04.

The first photo-electric collection subsystem 01 may include: a first laser 011, a first conduit accompanying optical cable 012, and a first signal processing component 013. The first laser 011 is configured to emit a first laser light to the first conduit tracing cable 012, and the first signal processing component 013 is configured to convert a first scattered light signal generated by the first laser light in the first conduit tracing cable 012 into a first electrical signal and transmit the first electrical signal to the leak detection subsystem 04, wherein the first scattered light signal is generated by sound vibration.

The sound waves or environmental noise generated by the leakage of the pipe cause vibration of the soil around the pipe, which causes rayleigh scattering of the first laser light transmitted in the first pipe accompanying optical cable 012. The first signal processing component 013 can receive the rayleigh scattered light signal and can convert the rayleigh scattered light signal into a first electrical signal. The first electrical signal can reflect the law of sound vibration.

The second photo-electric collection subsystem 02 may include: a second laser 021, a second pipe company cable 022, and a second signal processing component 023, the second laser 021 being configured to emit second laser light to the second pipe company cable 022, the second signal processing component 023 being configured to generate a second electrical signal from a second scattered light signal generated by the second laser light in the second pipe company cable 022 and transmit the second electrical signal to the leak detection subsystem 04, wherein the second scattered light signal is generated by a change in temperature.

The temperature change of the soil around the pipe causes the second pipe to generate raman scattering and brillouin scattering along with the second laser light transmitted in the optical fiber cable 022. The second signal processing 023 component may receive the at least one of the raman scattered light signal and the brillouin scattered light signal and may generate a second electrical signal reflecting a temperature change based on the received scattered light signal. Because the temperature of the soil around the pipeline is greatly changed due to the leakage of the pipeline, whether the pipeline has leakage or not can be judged according to the temperature change condition of the soil around the pipeline.

It should be understood that, in the embodiments of the present application, the pipeline accompanying optical cable refers to an optical cable laid in the same trench as the pipeline, and long-distance detection of the pipeline can be achieved by using the pipeline accompanying optical cable. Moreover, the first photoelectric acquisition subsystem 01 and the second photoelectric acquisition subsystem 02 can be deployed in a station control room along a pipeline, and both the first photoelectric acquisition subsystem 01 and the second photoelectric acquisition subsystem 02 can be powered by alternating current. Both the first laser 01 and the second laser 02 may be Distributed Feedback (DFB) lasers.

It should also be understood that in the present embodiment, the first conduit companion cable 012 and the second conduit companion cable 022 may be the same conduit companion cable.

The acoustic collection subsystem 03 may include: a plurality of acoustic wave sensors 031 and third signal processing subassembly 032, these a plurality of acoustic wave sensors 031 interval set up on the outer wall of pipeline for transmit the acoustic wave signal who gathers to this third signal processing subassembly 032, this third signal processing subassembly 032 is used for handling this acoustic wave signal, obtains the third signal of telecommunication, and with this third signal of telecommunication transmission to this leak detection subsystem 04.

As mentioned above, the soil around the pipe may vibrate due to pipe leakage or environmental noise, and the acoustic wave sensor 031 may directly collect the acoustic wave signal generated by the vibration. The acoustic wave acquisition subsystem 03 can be deployed in a high-consequence area because the detection precision of the acoustic wave sensor 031 is high. The high-consequence area refers to an area which can cause serious consequences after the pipeline leaks.

As shown in fig. 1, the leakage detecting subsystem 04 may be respectively connected to the first signal processing component 013, the second signal processing component 023 and the third signal processing component 032 (which may be connected by wire or wirelessly), and the leakage detecting subsystem 04 is configured to determine the temperature around the pipe according to the second electrical signal, detect whether the pipe leaks according to the temperature, determine the acoustic vibration law around the pipe according to the first electrical signal and the third electrical signal, and detect whether the pipe leaks according to the acoustic vibration law.

In the embodiment of the present application, the leak detection subsystem 04 may be connected to the first signal processing component 013 and the second signal processing component 023, respectively, via pipeline communication lines, and may be in wireless communication with the third signal processing component.

To sum up, the embodiment of the present application provides a pipeline leakage detection system, and this system can gather the first signal of telecommunication that is used for reflecting sound vibration law through first photoelectric acquisition subsystem, gathers the second signal of telecommunication that is used for reflecting the temperature height through second photoelectric acquisition subsystem to and gather the third signal of telecommunication that is used for reflecting sound vibration law through the sound wave acquisition subsystem. Therefore, the leakage detection subsystem can detect whether the pipeline leaks according to the three types of electric signals, and the reliability of pipeline leakage detection is effectively improved. In addition, the first photoelectric acquisition system and the second photoelectric acquisition system adopt the pipeline accompanying optical cables, so that long-distance detection of the pipeline can be realized, and the range of leakage detection is effectively enlarged. And because the detection precision of the sound wave detection subsystem is higher, the sound wave acquisition subsystem can be deployed in a high-consequence area to ensure the accurate detection of the pipeline leakage of the high-consequence area.

Fig. 2 is a schematic structural diagram of a first photoelectric acquisition subsystem and a second photoelectric acquisition subsystem provided in an embodiment of the present application. As shown in fig. 2, the first signal processing component 013 in the first photoelectric acquisition subsystem 01 may include: a first circulator 013a, a first amplifier 013b, a first filter 013c, a first photodetector 013d, and a first analog-to-digital converter 013 e.

The first circulator 013a is connected to the first laser 011, the first pipe accompanying cable 012, and the first amplifier 013b, respectively. The first circulator 013a is used for transmitting the first laser light emitted from the first laser 011 to the first pipeline accompanying optical cable 012, and collecting a first scattered light signal generated in the first pipeline accompanying optical cable 012 and transmitting to the first amplifier 013 b.

The first scattered light signal collected by the first circulator 013a is a backward rayleigh scattered light signal generated by the first laser beam in the first duct traveling optical cable 012 being influenced by sound vibration, and the backward rayleigh scattered light signal is a rayleigh scattered light signal propagating in a direction opposite to the first laser beam emission direction.

The first amplifier 013b is further connected to the first filter 013c, and is configured to amplify the first scattered light signals collected by the first circulator 013a and transmit the amplified first scattered light signals to the first filter 013 c. The first filter 013c is further connected to a first Photodetector (PD) 013d, for filtering the amplified first scattered light signal transmitted by the first amplifier 013b and transmitting the filtered first scattered light signal to the first photodetector 013 d. Since the scattered light signal generated by rayleigh scattering is weak, it is necessary to amplify the weak scattered light signal by the first amplifier 013b and to filter out noise generated during signal amplification by the first filter 013 c.

The first photodetector 013d is further connected to a first analog-to-digital converter (ADC) 013e for converting the filtered first scattered light signal transmitted by the first filter 013c into an analog first electrical signal and transmitting the analog first electrical signal to the first ADC 013 e. The first analog-to-digital converter 013e is also coupled to the leak detection subsystem 04 and is configured to convert the analog first electrical signal transmitted by the first photodetector 013d into a digital first electrical signal and transmit the digital first electrical signal to the leak detection subsystem 04.

In an embodiment of the present application, the first amplifier 013b may be an Erbium Doped Fiber Amplifier (EDFA). The first filter 013c may be a band-pass filter (BPF). The passband range of the BPF may be selected based on the frequency of the vibration signal to be detected and the surrounding soil environment.

Optionally, as shown in fig. 2, the first signal processing component 03 may further include: a first acousto-optic modulator 013f and a second amplifier 013g connected in series between the first laser 01 and the first circulator 013 a. The first acousto-optic modulator 013f is configured to acousto-optic modulate laser light emitted from the first laser 011, and transmit the modulated laser light to the second amplifier 013 g. The second amplifier 013g is configured to amplify the laser light transmitted by the first acousto-optic modulator 013f and transmit the amplified laser light to the first circulator 013 a.

Alternatively, as shown in fig. 2, the second conduit companion cable 022 can include a first fiber segment 022a and a second fiber segment 022 b. The second signal processing component 023 may further include: a beam splitter 023a, a second acousto-optic modulator 023b, an electro-optic modulator 023c, a second filter 023d, a second circulator 023e, a second photodetector 023f, and a second analog-to-digital converter 023 g.

The beam splitter 023a is connected to the second laser 021, the second optical modulator 023b and the electro-optical modulator 023c, and is configured to transmit the second laser beam to the second optical modulator 023b and the electro-optical modulator 023c after splitting. Alternatively, the beam splitter 023a can be an Optical Coupler (OC).

The second acousto-optic modulator 023b is connected to the second circulator 023e and configured to perform acousto-optic modulation on the split laser beam transmitted by the beam splitter 023a and transmit the acousto-optic modulated laser beam to the second circulator 023 e.

The electro-optical modulator 023c is further connected to the second filter 023d, and configured to perform electro-optical modulation on the other beam of laser light after being split transmitted by the beam splitter 023a, and transmit the beam of laser light after being subjected to the electro-optical modulation to the second filter 023 d.

The second filter 023d is also connected to one end of the first optical fiber segment 022a for filtering the laser light transmitted by the electro-optical modulator 023c and transmitting the filtered laser light to the first optical fiber segment 022 a.

The second circulator 023e is further connected to one end of the second optical fiber section 022b and the second photodetector 023f, respectively, for transmitting the laser light transmitted by the second optical modulator 023b into the second optical fiber section 022b and for transmitting the second scattered light signal transmitted by the second optical fiber section 022b to the second photodetector 023 f.

As shown in fig. 2, the first fiber segment 022a and the second fiber segment 022b are connected together at the distal end, that is, the first fiber segment 022a and the second fiber segment 022b may belong to one optical fiber. The far end of the pipeline may refer to an end far away from the station control room, for example, the far end of the pipeline may be 80 kilometers away from the station control room.

The second photodetector 023f is further connected to the second analog-to-digital converter 023g for generating an analog second electrical signal according to the optical signal transmitted by the second circulator 023e and transmitting the analog second electrical signal to the second analog-to-digital converter 023 g.

The second analog-to-digital converter 023g is also coupled to the leak detection subsystem 04 for converting the analog second electrical signal transmitted by the second photodetector to a digital second electrical signal and transmitting the digital second electrical signal to the leak detection subsystem 04.

Optionally, as shown in fig. 2, the second signal processing component 023 may further include: a first Polarization Controller (PC) 023h and a second polarization controller 023 i. The two polarization controllers can be used for avoiding polarization fading of the laser during transmission.

The first polarization controller 023h is respectively connected to the second acousto-optic modulator 023b and the second circulator 023e, and is configured to perform polarization processing on the laser light transmitted by the second acousto-optic modulator 023b, and transmit the polarization-processed laser light to the second circulator 023 e.

The second polarization controller 023i is respectively connected to the beam splitter 023a and the electro-optical modulator 023c, and is configured to perform polarization processing on the laser light transmitted by the beam splitter 023a, and transmit the laser light after polarization processing to the electro-optical modulator 023 c.

It should be appreciated that each of the first signal processing component 013 and the second signal processing component 023 may include an analog to digital converter, as shown in figure 2. Alternatively, the two signal processing components may share one analog-to-digital converter. That is, the first photodetector 013d and the second photodetector 023f may be connected to the same analog-to-digital converter. Therefore, the complexity of the first photoelectric acquisition subsystem and the second photoelectric acquisition subsystem can be simplified, and the manufacturing cost is saved.

Fig. 3 is a schematic structural diagram of an acoustic wave collection subsystem according to an embodiment of the present application. As shown in fig. 3, the acoustic wave acquisition subsystem 03 may include: a plurality of acoustic wave sensors 031 and a third signal processing assembly 032.

The plurality of acoustic wave sensors 031 can be arranged on the outer wall of the pipeline at intervals, and each acoustic wave sensor 031 is used for transmitting the collected acoustic wave signal to the third signal processing assembly 032.

The third signal processing component 032 is configured to process the acoustic signal to obtain a third electrical signal, and transmit the third electrical signal to the leak detection subsystem 04. The acoustic signals collected by the acoustic sensors 031 are analog electrical signals.

Optionally, as shown in fig. 3, the third signal processing component 032 may include: a third analog-to-digital converter 032a, a plurality of third amplifiers 032b and a plurality of third filters 032 c. The number of third amplifiers 032b included in the third signal processing component 032 and the number of third filters 032c included in the third signal processing component 032 are the same as the number of the acoustic sensors 031.

Each third filter 032c is connected to one acoustic wave sensor 031 and one third amplifier 032b, and each third filter 032c is configured to filter an acoustic wave signal transmitted by the connected acoustic wave sensor 031 and send the filtered acoustic wave signal to the third amplifier 032 b. The third filter 032c filters the collected sound wave signal to filter out the environmental noise in the sound wave signal. In an embodiment of the present application, each third filter 032c may be a low-pass filter (LPF), and the cut-off frequency of the LPF may be 300 hertz (Hz).

With reference to fig. 3, each third amplifier 032b is connected to the third adc 032a, and each third amplifier 032b is configured to amplify the filtered acoustic wave signal transmitted by the third filter 032c connected thereto and transmit the amplified acoustic wave signal to the third adc 032 a. Since the acoustic signal generated by the pipeline leakage is weak, the filtered acoustic signal needs to be amplified by the third amplifier 032 b.

The third adc 032a is further connected to the leakage sub-system 04, and the third adc 032a is configured to convert the amplified acoustic signal transmitted by each third amplifier 032b into a third electrical signal, and transmit the third electrical signal to the leakage detection sub-system.

Optionally, as shown in fig. 3, the acoustic wave collection subsystem 03 may further include: a solar cell 033 and a wireless communication component 034.

The solar cell 033 is connected to the plurality of acoustic wave sensors 031, the third signal processing component 032, and the wireless communication component 034, and is configured to supply power to the plurality of acoustic wave sensors 031, the third signal processing component 032, and the wireless communication component 034. Because the sound wave acquisition subsystem 03 adopts the solar battery for power supply, the sound wave acquisition subsystem 03 is more flexible in arrangement, and the energy can be saved by adopting solar power supply.

By way of example, and with reference to fig. 3, the solar cell 033 may comprise: a solar panel 033a, a solar controller 033b, and a battery 033 c.

The solar panels 033a are used to convert solar energy into electrical energy. This solar controller 033b is connected with this solar panel 033a and battery 033c for control solar panel 033a charges for battery 033c, and control battery 033c is these a plurality of sonic transducer 031, this third signal processing subassembly 032, and this wireless communication subassembly 034 power supply.

The wireless communication module 034 is respectively connected to the third signal processing module 032 and the leakage sub-system 04 for transmitting the third electrical signal to the leakage sub-system 04. By way of example, the wireless communication component 034 can be a 3rd-generation (3G) mobile communication component, or a 4G mobile communication component, or a 5G mobile communication component.

Optionally, as shown in fig. 3, the third signal processing component 03 may further include: sample holder 032d, multiplexer 032 e.

The sample holder 032d is respectively connected to the third amplifiers 032b and the multi-way switch 032e, and the sample holder 032d is configured to sample the acoustic signal transmitted by each third amplifier 032b and transmit the sampled multi-way acoustic signal to the multi-way switch 032 e.

The multiplexer 032e is further connected to the analog-to-digital converter 032a, and is configured to transmit the received multiple sampled acoustic signals to the analog-to-digital converter 032a path by path.

Optionally, as shown in fig. 3, the third signal processing component 032 may further include: a First Input First Output (FIFO) memory 032f, and a Micro Controller Unit (MCU) 032g, and a network controller 032 h.

The fifo 032f is connected to the adc 032a and the wireless communication component 034, respectively, for buffering the third electrical signal transmitted by the adc 032 a.

The mcu 032g is connected to the a/d converter 032a for controlling the a/d converter 032a to perform a/d conversion on the acoustic signals transmitted by the sample holder 032d in sequence.

The network controller 032h is connected to the wireless communication component 034, and the network controller 032h can be used to control the wireless communication component 034 to read the third electrical signal from the fifo 032f in a fifo order and transmit the third electrical signal to the leak detection subsystem 04.

Fig. 4 is a schematic structural diagram of a leak detection subsystem according to an embodiment of the present application, and as shown in fig. 4, the leak detection subsystem 04 may include: a communication component 041, a fourth signal processing component 042, and an alarm component 043.

The communication component 041 is connected to the fourth signal processing component 042 and the alarm component 043, respectively, and is configured to receive the first electrical signal, the second electrical signal, and the third electrical signal and transmit the first electrical signal, the second electrical signal, and the third electrical signal to the fourth signal processing component 042.

The fourth signal processing component 042 is configured to determine a sound vibration rule around the pipeline according to the first electrical signal and the third electrical signal, detect whether the pipeline leaks according to the sound vibration rule, determine a temperature change condition around the pipeline according to the second electrical signal, and detect whether the pipeline leaks according to the temperature change condition.

The fourth signal processing component 042 is also used to send an alarm instruction to the alarm component 043 when it is determined from any electrical signal that there is a leak in the pipe.

The alert component 043 is configured to generate an alert signal in response to the alert instruction. Wherein the alarm signal may be an acoustic signal, or an optical signal, or the alarm signal includes an acoustic signal and an optical signal.

Since the first electrical signal transmitted by the first photoelectric collection subsystem 01 and the third electrical signal transmitted by the sound wave collection subsystem 03 both can reflect the vibration law of the sound around the pipe, the first electrical signal and the third electrical signal can be processed by the same method.

Since a pipeline leak may cause soil around the pipeline to vibrate periodically in a specific frequency range, when the pipeline leaks, the first electrical signal and the third electrical signal received by the fourth signal processing assembly 042 are also periodic signals having a specific frequency range. When the pipeline has no leakage, the first electrical signal and the third electrical signal received by the fourth signal processing component 042 are both non-periodic signals without specific regularity. Thus, in embodiments of the present application, the fourth signal processing component 042 may employ a non-linear system sensitive to periodic signals to detect the first electrical signal and the third electrical signal.

That is, the fourth signal processing component 042 may input the received first electrical signal to the nonlinear system to obtain the first phase trajectory. And, the received third electrical signal may be input to the nonlinear system to obtain a second phase trajectory. The nonlinear system can be represented by the following nonlinear differential equation:

where s (t) is the electrical signal (i.e. the first electrical signal or the third electrical signal) received by the fourth signal processing component 042 at the time t to reflect the sound vibration law. The fourth signal processing component 042 inputs the electrical signal s (t) into the nonlinear differential equation shown in the above formula (1), so as to solve the first coordinate x and the second coordinate y corresponding to the time t. The first coordinate may be an abscissa, and the second coordinate may be an ordinate. The first coordinate x and the second coordinate y at different moments can be calculated by sequentially inputting the electric signals at different moments t into the nonlinear differential equation. And (x, y) acquired at different moments are drawn on a phase plane to obtain a phase track.

If the fourth signal processing component 042 detects that the phase trajectory is a periodic trajectory, that is, the phase trajectory is in a large-scale periodic state, it may be determined that there is a leak in the pipe. If the fourth signal processing component 042 detects that the phase trajectory is not a periodic trajectory, that is, the phase trajectory is in a chaotic state, it may be determined that there is no leakage in the pipeline.

For example, if the first phase trajectory or the second phase trajectory acquired by the fourth signal processing component 042 is in a large-scale periodic state as shown in fig. 5, it may be determined that the pipeline has a leak. If the first phase trajectory or the second phase trajectory acquired by the fourth signal processing component 042 is in a chaotic state as shown in fig. 6, it may be determined that there is no leakage in the pipeline.

Optionally, the fourth signal processing component 042 may also detect the presence of a component of a target frequency in the received electrical signal, wherein the target frequency is within a certain frequency range, since a pipe leak may cause the soil around the pipe to vibrate periodically within the frequency range. Specifically, the fourth signal processing component 042 may perform scale transformation on the first electrical signal to obtain a first signal component of a target angular frequency in the first electrical signal; inputting the first signal component of the target angular frequency to a nonlinear system to obtain a first phase track; and if the first phase track is a periodic track, determining that a component of a target frequency corresponding to the target angular frequency exists in the first electric signal.

For example, assume that the target frequency to be detected is f₀Then the target frequency f₀The angular frequency can be expressed as: omega₀＝2πf₀. The fourth signal processing component 042 can transform the electrical signal s (t) to be detected on the time axis to obtain

The fourth signal processing component 042 may then convert the transformed electrical signal

And inputting a nonlinear differential equation, and solving to obtain a phase track.

If the fourth signal processing component 042 detects that the phase trajectory is a periodic trajectory, that is, the phase trajectory is in a large-scale periodic state, it can be determined that the frequency f exists in the received electrical signal₀And thus a leak in the pipe can be determined.

To achieve reliable detection of a pipe leak, the fourth signal processing component 042 may determine a plurality of target frequencies within the frequency range, and detect components of each target frequency in turn. Referring to fig. 7, the process of detecting and analyzing any one of the first electrical signal and the third electrical signal by the fourth signal processing assembly 042 may include:

step 101, acquiring an electric signal to be detected.

For example, the fourth signal processing component 042 is used to analyze and process the first electrical signal. Assuming that the sampling frequency of the first optoelectronic collection subsystem to collect the electrical signal is 500Hz, the first electrical signal received by the fourth signal processing component 042 in the time period of 150 seconds can be represented as:

s(t)，t∈{0,0.002,0.004,...,149.998}。

and step 102, determining the target frequency to be detected.

In the embodiment of the present application, it is assumed that the frequency range to be detected is f₀To f_nWherein n is an integer greater than 1. The fourth signal processing component 042 may determine n +1 target frequencies to be detected within the frequency range. Assuming that the n +1 target frequencies to be detected are in an arithmetic progression, the ith target frequency f_iWith the i-1 st target frequency f_i-1Can satisfy the following conditions: f. of_i＝f_i-1+Δf。

Optionally, the fourth signal processing component 042 may be driven from a target frequency f₀Initially, each target frequency is detected in turn.

By way of example, assume that f₀＝10Hz，f_nThe fourth signal processing component 042 starts with 100Hz and Δ f 1HzThe target frequency of the secondary determination may be 10 Hz. After the detection of the target frequency of 10Hz is completed, the fourth signal processing component 042 may determine that the next target frequency to be detected is 11Hz, and so on until the fourth signal processing component 042 updates the target frequency to be detected to f_n＝100Hz。

It should be understood that the fourth signal processing component 042 may sequentially determine the target frequency to be detected according to the order of the frequencies from small to large; or, the fourth signal processing component 042 may also sequentially determine the target frequency to be detected according to the order of the frequencies from large to small; or, the fourth signal processing component 042 may also randomly select a target frequency to be detected from the frequency range, and only needs to ensure that each target frequency in the frequency range can be traversed.

And 103, carrying out scale transformation on the electric signal according to the target frequency to obtain a signal component of the target angular frequency in the electric signal.

By way of example, assume that the target frequency f to be detected₀10Hz, the target frequency may be represented by ω using an angular frequency₀20 pi. The fourth signal processing component 042 can process the electrical signal s to be detected₀(t) obtaining by performing scale transformation by cubic spline interpolation

And 104, inputting the signal component of the target angular frequency into a nonlinear system to obtain a phase track.

Illustratively, the fourth signal processing component 042 may convert the transformed electrical signal

Inputting the phase trajectory into a nonlinear system as shown in formula (1).

And step 105, determining whether the pipeline has leakage according to the phase trajectory.

If the fourth signal processing component 042 detects that the phase trajectory is a periodic trajectory, that is, the phase trajectory is in a large-scale periodic state, it may be determined that there is a leakage in the pipelineAnd step 106 is performed. If the fourth signal processing component 042 detects that the phase trajectory is not a periodic trajectory, that is, the phase trajectory is in a chaotic state, it can be determined that the frequency f does not exist in the electrical signal₀And step 108 may be performed.

And step 106, determining the leakage position.

Optionally, the fourth signal processing component 042 may also determine the location of the pipe leakage after determining that the pipe has a leakage according to the electrical signal.

In the embodiment of the present application, the first optoelectronic collection subsystem 01 obtains the vibration intensity of the soil around the pipeline through the first pipeline accompanying optical cable 012, and the first pipeline accompanying optical cable 012 is equivalent to a plurality of vibration sensors arranged at equal intervals. Assuming that the spatial resolution of the first conduit accompanying cable 012 is D and the length thereof is L, the first conduit accompanying cable 012 corresponds to

A sensor, wherein,

indicating a rounding down. When the fourth signal processing component 042 determines that there is a leak in the pipeline according to the first electrical signal, the position of the vibration sensor that detects the leak at the first time may be determined as the position of the pipeline leak. Wherein the position of the vibration sensor can be calculated from the propagation distance of the first scattered light signal, and the positioning error is

When the pipeline leaks, the first laser passes through the vibration sensor at the leakage position, and rayleigh scattering occurs under the influence of sound vibration. The fourth signal processing module 042 can determine the location of the duct leak based on the time when the first scattered light signal from the vibration sensor reaches the first photodetector 013d, and the speed of light. The scattered light from each sensor arrives at the first photodetector 013d at different times, so that the position of the respective vibration sensor can be resolved. For example, the fourth signal processing component 042 mayA first time instant when the first laser 011 emits the first laser light and a second time instant when the first photodetector 013d receives the first scattered light signal are determined. The fourth signal processing component 042 may further determine a transmission time period of the first scattered light signal according to the first time and the second time, and determine a location of the duct leakage according to the time period and the speed of light.

Since the deployment position of each acoustic wave sensor 031 in the acoustic wave acquisition subsystem 03 is determined, when the fourth signal processing assembly 042 determines that the pipeline has a leak according to the third electrical signal acquired by the acoustic wave acquisition subsystem 03, the position of the acoustic wave sensor 031 acquiring the acoustic wave signal caused by the leak can be determined as the position of the pipeline leak. The acoustic wave sensor 031 that collects the acoustic wave signal that enters the large-scale periodic state at the earliest time is the acoustic wave sensor closest to the leak point. Assuming that the detection radius of a single acoustic wave sensor 031 is r and the distance between two adjacent acoustic wave sensors 031 is m, then when

When the positioning error is

When in use

The positioning error is ± r.

And step 107, sending an alarm instruction.

The fourth signal processing component 042 may send an alarm instruction to the alarm component 043 after determining that there is a leak in the pipe according to the electrical signal.

And step 108, judging whether the detection of all target frequencies in the frequency range is finished.

The fourth signal processing component 042 determines that the frequency f does not exist in the electrical signal according to the phase trace in the step 105₀Can continue to detect whether the detection of all target frequencies in the frequency range is completed. If not, step 102 may be executedThat is, the fourth signal processing component 042 may determine the next target frequency to be detected, and continue to perform the above steps 103 to 105, and if the fourth signal processing component 042 determines that the detection of all the target frequencies in the frequency range is completed, then step 101 may be performed, that is, the electrical signal of the next time period may continue to be acquired.

In the embodiment of the present application, the fourth signal processing component 042 can also calculate the variation of the temperature around the pipeline through the second electrical signal. The rate of change of the soil temperature around the pipe due to the change in the ambient temperature is substantially uniform, and the change in the temperature due to the leakage of the pipe causes the amount of change in the soil temperature around the pipe at the location of the leakage to be different from that at other locations. Therefore, the fourth signal processing component 042 can determine whether there is a leak in the pipeline by detecting the temperature change of the pipeline. When the temperature around a pipeline at a certain position is changed too much, the pipeline at the certain position can be determined to have leakage.

The fourth signal processing component 042 calculates the variation of the ambient temperature of the pipeline by the second electrical signal, and determines whether there is a leak in the pipeline according to the temperature variation. Referring to fig. 8, the process of the fourth signal processing component 042 determining whether there is a leak in the pipe according to the second electrical signal may include:

and step 201, determining the temperature variation around the pipeline according to the acquired second electric signal.

In the embodiment of the present application, after the fourth signal processing component 042 receives the second electrical signal, the temperature variation around the pipeline may be determined according to the second electrical signal.

Temperature changes around the tube will cause deformation of the cable and the second tube will generate brillouin scattering and raman scattering with the laser light transmitted in the cable 022. The brillouin scattering light has a certain frequency shift, called brillouin frequency shift, with respect to the second laser light (i.e., incident light) emitted by the second laser 021. The amount of change in brillouin frequency shift occurring everywhere in the second tubing accompanying optical cable 022 is linear with the temperature around the tubing everywhere, so the fourth signal processing component 042 can determine the amount of change in temperature around the tubing everywhere based on the amount of frequency shift of the received brillouin scattered light.

Optionally, the second photoelectric acquisition subsystem 02 may determine brillouin frequency shift everywhere in the second conduit tracing optical fiber cable 022 by means of frequency scanning (referred to as frequency sweeping). As shown in fig. 3, the second laser that second laser 021 sent divides into two bundles of laser through beam splitter 023a, and a bundle of laser passes through second sound optical modulator 023b modulation for the pulsed light and transmits to first optic fibre section 022a, and another bundle of laser passes through electric light modulator 023c modulation for continuous light and transmits to second optic fibre section 022b, and this first optic fibre section 022a and second optic fibre section 022b belong to same root optical fiber, and also be pulse light and continuous light inject into same root optical fiber from the both ends of optic fibre respectively. In which the pulsed light in the fiber is subject to temperature and brillouin scattering occurs. When the pulsed light and the continuous light overlap in the second traveling fiber optic cable 022, energy transfer occurs between the pulsed light and the continuous light through the acoustic wave field due to the stimulated brillouin amplification. Since the magnitude of the energy transfer is related to the frequency difference between the two optical waves, the energy transfer occurs when the frequency difference falls within the brillouin frequency shift range, and brillouin scattering generated by pulsed light is enhanced, so that the frequency shift amount of brillouin scattered light at each position in the second conduit accompanying optical cable 022 can be obtained by scanning the frequency difference between the two laser beams and the magnitude of the transferred energy at each frequency difference.

Assuming that the second conduit companion cable 022 has a length of l and a spatial resolution of d, the second conduit companion cable 022 may be equivalent to the second conduit companion cable 022

A temperature sensor, wherein,

indicating a rounding down. The fourth signal processing component 042 can acquire the temperature collected by 2m +1 temperature sensors by taking the ith temperature sensor as the center and m × d as the radius. Where m is an integer greater than 1, the fourth signal processing component 042 is at t₀The 2m +1 temperatures acquired at a time may be represented as:

at t₀T after the moment₀The 2m +1 temperatures acquired at time + Δ t may be expressed as:

it should be understood that the 2m +1 temperatures acquired at each time point may be obtained by the fourth signal processing component 042 according to an initial temperature obtained by measurement in advance and a temperature offset determined based on the frequency shift amount of the brillouin scattering light.

The amount of change in temperature collected by the 2m +1 temperature sensors determined by the fourth signal processing component 042 can be expressed as:

step 202, determining an average value and a minimum value of the temperature variation according to the plurality of temperature variations.

The average value of the variation Δ T of the temperature collected by the 2m +1 temperature sensors can be represented as:

the minimum value of the variation of the temperature collected by the 2m +1 temperature sensors can be represented as:

step 203, judging whether the temperature around the pipeline is reduced, and judging whether the difference value between the average value and the minimum value of the temperature variation is larger than a temperature threshold value.

If the fourth signal processing component 042 determines that the temperature around the pipeline is decreased and the difference between the average value and the minimum value of the temperature change is greater than the temperature threshold, it may be determined that there is a leakage in the pipeline, and step 204 may be executed; if the fourth signal processing component 042 determines that the temperature around the pipeline does not decrease, or the difference between the average value and the minimum value of the temperature variation is not greater than the temperature threshold, it may be determined that there is no leakage in the pipeline, and step 201 may be continuously performed, that is, the second electrical signal of the next time period may be continuously acquired.

For example, assuming that the temperature threshold is 2, when the fourth signal processing component 042 detects T_min<0, and | T_min-T_mean|>2, it can be determined that the pipe is leaking.

And step 204, determining the leakage position.

The fourth signal processing component 042 may further determine the location of the pipeline leak after determining that there is a leak in the pipeline. T is_minThe position of the corresponding temperature sensor is the position of the pipeline leakage. Wherein the position of the temperature sensor can be calculated from the propagation distance of the second scattered light signal, and the positioning error is

The propagation distance of the second scattered light signal may be determined by using an optical time-domain reflectometer (OTDR) principle.

Optionally, as shown in fig. 4, the leak detection subsystem may further include a data management component 044, and the data management component 044 is connected to the fourth signal processing component 042 for storing historical data and alarm records. The historical data may include the electrical signals received by the fourth signal processing component 042 and the processing results (e.g., phase traces) obtained by processing the electrical signals. The data stored in the data management component 044 may be used for playback analysis and alarm statistics.

To sum up, the embodiment of the present application provides a pipeline leakage detection system, and this system can gather the first signal of telecommunication that is used for reflecting sound vibration law through first photoelectric acquisition subsystem, gathers the second signal of telecommunication that is used for reflecting the temperature height through second photoelectric acquisition subsystem to and gather the third signal of telecommunication that is used for reflecting sound vibration law through the sound wave acquisition subsystem. The system also inputs the first electric signal and the third electric signal to the nonlinear system through the leakage detection subsystem to obtain a phase track, and can judge whether the pipeline has leakage according to the state of the phase track, so that the accuracy of pipeline leakage detection is improved.

In addition, the system also acquires the temperature change condition of the pipeline according to the second electric signal through the leakage detection subsystem, so that the pipeline leakage is detected, whether the pipeline leaks or not is detected through various modes, and the reliability of pipeline leakage detection is effectively improved. In addition, the first photoelectric acquisition system and the second photoelectric acquisition system adopt the pipeline accompanying optical cables, so that long-distance detection of the pipeline can be realized, and the range of leakage detection is effectively enlarged. And because the detection precision of the sound wave detection subsystem is higher, the sound wave acquisition subsystem can be deployed in a high-consequence area to ensure the accurate detection of the pipeline leakage of the high-consequence area.

The embodiment of the present application provides a method for detecting a pipeline leakage, which may be applied to the leakage detecting subsystem 04 in the pipeline leakage detecting system provided in the above embodiment. For example, it may be applied to the fourth signal processing component 042 in the leak detection subsystem 04 as shown in fig. 4. As shown in fig. 9, the pipe leakage detecting method may include:

step 301, receiving a first electrical signal sent by a first photoelectric collection subsystem, where the first electrical signal is obtained by converting a first scattered light signal generated in a first pipeline accompanying optical cable, and the first scattered light signal is generated by sound vibration.

And step 302, receiving a second electric signal sent by the second photoelectric acquisition subsystem, wherein the second electric signal is generated according to a second scattered light signal generated in the second pipeline accompanying optical cable, and the second scattered light signal is generated by temperature change.

And 303, receiving a third electric signal sent by the sound wave acquisition subsystem, wherein the third electric signal is obtained by processing the sound wave signal acquired by the sound wave sensor.

And step 304, determining a sound vibration law around the pipeline according to the first electric signal and the third electric signal, and detecting whether the pipeline leaks or not according to the sound vibration law.

And step 305, determining the temperature change condition around the pipeline according to the second electric signal, and detecting whether the pipeline leaks according to the temperature change condition.

And step 306, if the pipeline is determined to have the leakage, determining the leakage position and sending an alarm instruction.

It should be understood that, for the implementation process of step 301 to step 306, reference may be made to the related description of the fourth signal processing element 042 in the foregoing system embodiment, and details are not described herein again.

It should also be understood that the execution order of the steps of the pipeline leakage detection method provided by the embodiment of the present application may be adjusted according to the situation, for example, the order of step 301, step 302, and step 303 may be changed, and step 305 may also precede step 304.

In summary, the embodiment of the present application provides a method for detecting a pipeline leakage, where a leakage detection subsystem may determine a sound vibration law around a pipeline according to a first electrical signal and a third electrical signal, and detect whether there is a leakage in the pipeline according to the sound vibration law. The leakage detection subsystem can also acquire the temperature change condition of the pipeline according to the second electric signal to realize the detection of the pipeline leakage, so that whether the pipeline leaks or not can be detected in multiple modes, and the reliability of the pipeline leakage detection is effectively improved.

In this application, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "plurality" means two or more unless expressly limited otherwise.

The above description is only exemplary of the present application and should not be taken as limiting the present application, and any modifications, equivalents, improvements and the like that are made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A pipeline leak detection system, the system comprising: the system comprises a first photoelectric acquisition subsystem, a second photoelectric acquisition subsystem, a sound wave acquisition subsystem and a leakage detection subsystem;

2. The system of claim 1, wherein the first signal processing component comprises: the device comprises a first circulator, a first amplifier, a first filter, a first photoelectric detector and a first analog-to-digital converter;

3. The system of claim 2, wherein the first signal processing component further comprises: a first acousto-optic modulator and a second amplifier connected in series between the first laser and the first circulator;

4. The system of claim 1, wherein the second duct companion cable comprises a first fiber segment and a second fiber segment; the second signal processing assembly includes: the device comprises a beam splitter, a second acoustic optical modulator, an electro-optical modulator, a second filter, a second circulator, a second photoelectric detector and a second analog-to-digital converter;

the second filter is also connected with one end of the first optical fiber section and is used for filtering laser transmitted by the electro-optical modulator and transmitting the filtered laser to the first optical fiber section;

5. The system of claim 1, wherein the third signal processing component comprises: a third analog-to-digital converter, a plurality of third amplifiers, and a plurality of third filters;

6. The system of claim 5, wherein the acoustic collection subsystem further comprises: a solar cell and a wireless communication component;

7. The system of claim 6, wherein the third signal processing component further comprises: a sample holder, a multi-way switch;

8. The system of any of claims 1 to 7, wherein the leakage sub-system comprises: the communication component, the fourth signal processing component and the alarm component are arranged on the base;

9. The system of claim 8, wherein the fourth signal processing component is configured to:

10. A method of pipeline leak detection for use in a leak detection subsystem in a system according to any of claims 1 to 9, the method comprising: