CN114440141B

CN114440141B - Pipeline leakage detection method and system

Info

Publication number: CN114440141B
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: 2023-09-26
Anticipated expiration: 2040-10-30
Also published as: CN114440141A

Abstract

The application discloses a pipeline leakage detection method and system, and belongs to the field of oil and gas storage and transportation. The pipe leak detection system includes: the system comprises a first photoelectric acquisition subsystem, a second photoelectric acquisition subsystem, an acoustic wave acquisition subsystem and a leakage detection subsystem. The first photoelectric acquisition subsystem can acquire a first electric signal for reflecting the sound vibration rule, 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 rule. Therefore, the leakage detection subsystem can detect whether the pipeline leaks according to 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 transportation of oil and gas products. Leakage is a main factor affecting 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 gas pipeline leaks, serious safety accidents are extremely easy to cause, so that the real-time detection of the leakage of the oil gas pipeline is very important.

In the related art, because leakage sound waves can be generated when an oil gas pipeline leaks, a sound wave sensor can be arranged on the pipeline generally, and the leakage sound waves are 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 in 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 a pipeline leakage detection system, which can solve the problem of lower pipeline leakage detection precision in the related technology. The technical scheme is as follows:

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

the first photoelectric acquisition subsystem comprises: the system comprises a first laser, a first pipeline companion cable and a first signal processing component, wherein the first laser is used for emitting first laser light to the first pipeline companion cable, and the first signal processing component is used for converting a first scattered light signal generated by the first laser light in the first pipeline companion cable into a first electric signal and transmitting the first electric signal to the leakage detection subsystem, wherein the first scattered light signal is generated by sound vibration;

The second photoelectric acquisition subsystem comprises: the system comprises a first laser, a first pipeline companion cable and a first signal processing component, wherein the first laser is used for emitting first laser light to the first pipeline companion cable, the first signal processing component is used for generating a first electric signal according to a first scattered light signal generated by the first laser light in the first pipeline companion cable, and transmitting the first electric signal to the leakage detection subsystem, and the first scattered light signal is generated by temperature change;

the acoustic wave acquisition subsystem includes: the plurality of acoustic wave sensors are arranged on the pipeline at intervals and used for transmitting the acquired acoustic wave signals to the third signal processing assembly, and the third signal processing assembly is used for processing the acoustic wave signals to obtain third electric signals and transmitting the third electric signals to the leakage detection subsystem;

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 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 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;

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 also connected with the first photoelectric detector and is used for filtering the first scattered light signal transmitted by the first amplifier and transmitting the first scattered light signal to the first photoelectric detector;

the first photoelectric detector is further connected with the first analog-to-digital converter and is used for converting the filtered first scattered light signal transmitted by the first filter into an analog first electric signal and transmitting the analog first electric signal to the first analog-to-digital converter;

The first analog-to-digital converter is also connected with the leakage detection subsystem and is used for converting the analog first electric signal into a digital first electric signal and transmitting the digital first electric signal to the leakage detection subsystem.

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

the first acousto-optic modulator is used for carrying out acousto-optic modulation on the first laser emitted by the first laser and transmitting the first laser after the acousto-optic modulation to the second amplifier;

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

Optionally, the second pipeline accompanying optical cable comprises a first optical fiber section and a second optical fiber section; 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 optical modulator and the electro-optic modulator and is used for respectively transmitting the second laser after being split to the second optical modulator and the electro-optic modulator;

The second acoustic optical modulator is connected with the second circulator and is used for carrying out acoustic optical modulation on a beam of laser transmitted by the beam splitter and transmitting the laser after acoustic optical modulation to the second circulator;

the electro-optical modulator is also connected with the second filter and is used for carrying out electro-optical modulation on the other beam of laser transmitted by the beam splitter and transmitting the laser after 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 laser to the first optical fiber section;

the second circulator is also connected with one end of the second optical fiber section and the second photoelectric detector respectively, and is used for transmitting the laser transmitted by the second optical modulator to the second optical fiber section and transmitting a second scattered light signal transmitted by the second optical fiber section to the second photoelectric detector, wherein the other end of the first optical fiber section is connected with the other end of the second optical fiber section;

the second photoelectric detector is also connected with the second analog-to-digital converter and is used for converting the optical signal transmitted by the second circulator into an analog second electric signal and transmitting the analog second electric signal to the second analog-to-digital converter;

The second analog-to-digital converter is also connected 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 connected with one sound wave sensor and one third amplifier respectively and is used for filtering sound wave signals transmitted by the sound wave sensor and then transmitting the sound wave signals to the third amplifier;

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

the third analog-to-digital converter is further connected with the leakage subsystem and is used for converting the amplified acoustic wave signals transmitted by each third amplifier into third electric signals and transmitting the third electric signals to the leakage detection subsystem.

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

The solar battery is respectively connected with the plurality of acoustic wave sensors, the third signal processing assembly and the wireless communication assembly and is 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 subsystem and is used for transmitting the third electric signal to the leakage subsystem.

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

the sampling retainers are respectively connected with the third amplifiers and the multi-way switch and are 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 multipath switch is also connected with the analog-to-digital converter and is used for transmitting the received multipath sampled sound wave signals to the analog-to-digital converter in a path-by-path mode.

Optionally, the leakage subsystem includes: a communication component, a fourth signal processing component and an alarm component;

the communication component is respectively connected with the fourth signal processing component and the alarm component 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 component;

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 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 according to the temperature change condition;

the fourth signal processing component is further used for determining the 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 track and the second phase track is a periodic track, determining that leakage exists in the pipeline;

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 a temperature threshold value, determining that the pipeline has leakage.

In another aspect, a method of pipeline leak detection is provided for use in a leak detection subsystem, the method comprising:

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 optical accompanying cable, and the first scattered light signal is generated by sound vibration;

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

receiving a third electric signal sent by the acoustic wave acquisition subsystem, wherein the third electric signal is obtained by processing an acoustic wave signal acquired by the acoustic 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 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 according to the temperature change condition.

The technical scheme provided by the application has the beneficial effects that at least the following steps are included:

The embodiment of the application provides a pipeline leakage detection method and a system, wherein the system can acquire a first electric signal for reflecting a sound vibration rule through a first photoelectric acquisition subsystem, acquire a second electric signal for reflecting temperature through a second photoelectric acquisition subsystem and acquire a third electric signal for reflecting the sound vibration rule through an acoustic wave acquisition subsystem. Therefore, the leakage detection subsystem can detect whether the pipeline leaks according to three types of electric signals, and the reliability of pipeline leakage detection is effectively improved. In addition, as the first photoelectric acquisition system and the second photoelectric acquisition system adopt the pipeline optical cable, the long-distance detection of the pipeline can be realized, and the leakage detection range is effectively improved. And because the detection accuracy of the acoustic wave detection subsystem is higher, the acoustic wave acquisition subsystem can be deployed in a high-result area so as to ensure the accurate detection of the pipeline leakage in the high-result area.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a piping leakage detection system according to 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 according to an embodiment of the present application;

FIG. 3 is a schematic diagram of an acoustic wave acquisition subsystem according to an embodiment of the present application;

FIG. 4 is a schematic diagram of a leakage subsystem according to an embodiment of the present application;

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

fig. 6 is a schematic diagram of a chaotic phase trajectory according to an embodiment of the present application;

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

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

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

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the embodiments of the present application will be described in further detail with reference to the accompanying drawings.

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

The first photoelectric acquisition subsystem 01 may include: a first laser 011, a first pipe partner cable 012, and a first signal processing component 013. The first laser 011 is configured to emit a first laser light to the first pipe-concomitant optical cable 012, and the first signal processing unit 013 is configured to convert a first scattered light signal generated by the first laser light in the first pipe-concomitant optical 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.

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

The second photoelectric acquisition subsystem 02 may include: a second laser 021, a second pipe partner cable 022 and a second signal processing component 023, the second laser 021 is used for emitting a second laser light to the second pipe partner cable 022, the second signal processing component 023 is used for generating a second electric signal according to a second scattered light signal generated by the second laser light in the second pipe partner cable 022 and transmitting the second electric signal to the leakage detection subsystem 04, wherein the second scattered light signal is generated by temperature change.

The temperature change of the soil around the pipe causes raman scattering and brillouin scattering of the second laser light transmitted in the second pipe-concomitant optical cable 022. The second signal processing 023 component may receive 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 according to the received scattered light signal. Because the temperature of the soil around the pipeline can be greatly changed due to the leakage of the pipeline, whether the pipeline is leaked or not can be judged according to the temperature change condition of the soil around the pipeline.

It should be understood that, in the embodiment of the present application, the pipeline accompanying optical cable refers to an optical cable laid on a ditch with a pipeline, and long-distance detection of the pipeline can be achieved by adopting the pipeline accompanying optical cable. And, this first photoelectric acquisition subsystem 01 and second photoelectric acquisition subsystem 02 can be disposed in the station accuse room along the pipeline, and this first photoelectric acquisition subsystem 01 and second photoelectric acquisition subsystem 02 all can adopt alternating current power supply. The first laser 01 and the second laser 02 may each be a distributed feedback (distributed feedback, DFB) laser.

It should also be appreciated that in embodiments of the present application, the first conduit accompanying cable 012 and the second conduit accompanying cable 022 may be the same conduit accompanying cable.

The acoustic wave acquisition subsystem 03 may include: the plurality of acoustic wave sensors 031 and the third signal processing component 032, the plurality of acoustic wave sensors 031 are arranged on the outer wall of the pipeline at intervals, and are used for transmitting the collected acoustic wave signals to the third signal processing component 032, and the third signal processing component 032 is used for processing the acoustic wave signals to obtain third electric signals, and transmitting the third electric signals to the leak detection subsystem 04.

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

As shown in fig. 1, the leak detection subsystem 04 may be connected (may be a wired connection or a wireless connection) to the first signal processing component 013, the second signal processing component 023, and the third signal processing component 032, respectively, and the leak detection subsystem 04 is configured to determine a temperature around the pipe according to the second electrical signal, and to detect whether the pipe leaks according to the temperature, and to determine a sound vibration law around the pipe according to the first electrical signal and the third electrical signal, and to detect whether the pipe leaks according to the sound vibration law.

In an 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 a pipe communication line, and may establish a wireless communication connection with the third signal processing component.

In summary, the embodiment of the application provides a pipeline leakage detection system, which 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 an acoustic wave collection subsystem. Therefore, the leakage detection subsystem can detect whether the pipeline leaks according to three types of electric signals, and the reliability of pipeline leakage detection is effectively improved. In addition, as the first photoelectric acquisition system and the second photoelectric acquisition system adopt the pipeline optical cable, the long-distance detection of the pipeline can be realized, and the leakage detection range is effectively improved. And because the detection accuracy of the acoustic wave detection subsystem is higher, the acoustic wave acquisition subsystem can be deployed in a high-result area so as to ensure the accurate detection of the pipeline leakage in the high-result area.

Fig. 2 is a schematic structural diagram of a first photoelectric acquisition subsystem and a second photoelectric acquisition subsystem according to 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 comprise: a first circulator 013a, a first amplifier 013b, a first filter 013c, a first photodetector 013d, and a first analog-to-digital converter 013e.

The first circulator 013a is connected to the first laser 011, the first pipe-concomitant optical cable 012, and the first amplifier 013b, respectively. The first circulator 013a is configured to transmit the first laser light emitted from the first laser 011 to the first pipe-concomitant optical cable 012, and collect a first scattered light signal generated in the first pipe-concomitant optical cable 012 and transmit it to the first amplifier 013b.

The first scattered light signal collected by the first circulator 013a is a backward rayleigh scattered light signal generated by the influence of the sound vibration on the first laser light in the first pipe accompanying optical cable 012, and the backward rayleigh scattered light signal is a rayleigh scattered light signal transmitted along a direction opposite to the first laser light transmitting direction.

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

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

In an embodiment of the application, the first amplifier 013b may be an erbium doped fiber amplifier (erbium doped fiber application amplifier, EDFA). The first filter 013c may be a band-pass filter (BPF). The passband 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 013a. The first acousto-optic modulator 013f is configured to perform acousto-optic modulation on the laser light emitted by the first laser 011, and transmit the modulated laser light to the second amplifier 013g. The second amplifier 013g is configured to amplify the laser light transmitted from the first acousto-optic modulator 013f and transmit the amplified laser light to the first circulator 013a.

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

The beam splitter 023a is respectively connected with the second laser 021, the second optical modulator 023b and the electro-optical modulator 023c, and is used for respectively transmitting the second laser beam to the second optical modulator 023b and the electro-optical modulator 023c after splitting. Alternatively, the beam splitter 023a may be an Optical Coupler (OC).

The second acoustic optical modulator 023b is connected to the second circulator 023e, and is configured to perform acoustic optical modulation on a beam of laser light after beam splitting transmitted by the beam splitter 023a, and transmit the beam of laser light after acoustic optical modulation to the second circulator 023e.

The electro-optical modulator 023c is further connected to the second filter 023d, and is configured to electro-optically modulate another beam of laser light after beam splitting transmitted by the beam splitter 023a, and transmit the beam of laser light after electro-optical modulation to the second filter 023d.

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

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 023f.

Wherein, as shown in fig. 2, the first optical fiber section 022a and the second optical fiber section 022b are connected together at the distal end, i.e. the first optical fiber section 022a and the second optical fiber section 022b may belong to one optical fiber. Wherein the distal end of the conduit may refer to the end that is farther from the standing room, e.g., the distal end of the conduit may be 80 kilometers from the standing room.

The second photodetector 023f is further connected to the second analog-to-digital converter 023g, and is configured to generate an analog second electrical signal according to the optical signal transmitted by the second circulator 023e and transmit the analog second electrical signal to the second analog-to-digital converter 023g.

The second analog-to-digital converter 023g is also coupled to the leak detection subsystem 04 for converting the second photo-detectably transmitted analog second electrical signal 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 (polarization control, PC) 023h and a second polarization controller 023i. The two polarization controllers may be used to avoid polarization fading of the laser during transmission.

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

The second polarization controller 023i is connected to the beam splitter 023a and the electro-optical modulator 023c, respectively, 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 023c.

It should be appreciated that each of the first signal processing component 013 and the second signal processing component 023 may comprise an analog-to-digital converter, as shown in fig. 2. Alternatively, the two signal processing components may also share an 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 acquisition 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 component 032.

The plurality of acoustic wave sensors 031 may be disposed on an outer wall of the pipe at intervals, each acoustic wave sensor 031 being configured to transmit the acquired 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. Wherein, the acoustic wave signals collected by the acoustic wave sensors 031 are all 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 032c. The number of third amplifiers 032b included in the third signal processing unit 032 and the number of third filters 032c included therein are the same as the number of acoustic wave 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 acoustic wave sensor 031 connected to the third filter and send the filtered acoustic wave signal to the third amplifier 032b. The third filter 032c filters the collected acoustic wave signal to remove the environmental noise in the acoustic wave signal. In an embodiment of the present application, each of the third filters 032c may be a low-pass filter (LPF), and the cut-off frequency of the LPF may be 300 hertz (Hz).

With continued reference to fig. 3, each third amplifier 032b is connected to the third analog-to-digital converter 032a, and each third amplifier 032b is configured to amplify the filtered acoustic wave signal transmitted by the third filter 032c to which it is connected and transmit the amplified acoustic wave signal to the third analog-to-digital converter 032a. Since the acoustic wave signal generated by the pipe leakage is weak, the filtered acoustic wave signal needs to be amplified by the third amplifier 032 b.

The third analog-to-digital converter 032a is further connected to the leakage subsystem 04, and the third analog-to-digital converter 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 subsystem.

Optionally, as shown in fig. 3, the acoustic wave acquisition subsystem 03 may further include: a solar cell 033 and a wireless communication assembly 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, respectively, for supplying power to the plurality of acoustic wave sensors 031, the third signal processing component 032, and the wireless communication component 034. Because the acoustic wave acquisition subsystem 03 is powered by a solar battery, the deployment of the acoustic wave acquisition subsystem 03 is more flexible, and energy can be saved by adopting solar power supply.

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

The solar panel 033a is used to convert solar energy into electrical energy. The solar controller 033b is connected to the solar panel 033a and the storage battery 033c, and is configured to control the solar panel 033a to charge the storage battery 033c, and control the storage battery 033c to supply power to the plurality of acoustic wave sensors 031, the third signal processing component 032, and the wireless communication component 034.

The wireless communication component 034 is connected to the third signal processing component 032 and the leakage subsystem 04, respectively, for transmitting the third electrical signal to the leakage subsystem 04. The wireless communication component 034 may be a 3rd generation (3G) mobile communication component, or a 4G mobile communication component, or a 5G mobile communication component, for example.

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

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

The multiplexing switch 032e is further connected to the analog-to-digital converter 032a, and is configured to transmit the received sampled acoustic wave signals to the analog-to-digital converter 032a.

Optionally, as shown in fig. 3, the third signal processing component 032 may further include: a first-in first-out (first input first output, FIFO) memory 032f, and a micro control unit (micro controller unit, MCU) 032g, and a network controller 032h.

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

The micro control unit 032g is connected to the analog-to-digital converter 032a, and is used for controlling the analog-to-digital converter 032a to sequentially perform analog-to-digital conversion on the acoustic wave signal transmitted by the sample holder 032 d.

The network controller 032h is connected to the wireless communication module 034, and the network controller 032h can be used to control the wireless communication module 034 to read the third electrical signals from the fifo 032f in a fifo order and transmit the third electrical signals 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 respectively connected with the fourth signal processing component 042 and the alarm component 043, 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 component 042.

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

The fourth signal processing assembly 042 is also configured to send an alarm command to the alarm assembly 043 when it is determined from any of the electrical signals that a leak exists in the conduit.

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

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

Since the pipe leakage may cause the soil around the pipe to periodically vibrate in a specific frequency range, the first and third electrical signals received by the fourth signal processing assembly 042 are also periodic signals having a specific frequency range when the pipe leakage occurs. And when the pipeline does not leak, the first electric signal and the third electric signal received by the fourth signal processing component 042 are non-periodic signals without specific rules. Thus, in embodiments of the present application, the fourth signal processing component 042 may employ a nonlinear system that is 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 a 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 expressed by the following nonlinear differential equation:

wherein s (t) is an electrical signal (i.e. the first electrical signal or the third electrical signal) received by the fourth signal processing component 042 at time t and used for reflecting the sound vibration rule. The fourth signal processing component 042 inputs the electrical signal s (t) into the nonlinear differential equation shown in the above formula (1), and can 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. By sequentially inputting the electric signals at different moments t into the nonlinear differential equation, the first coordinate x and the second coordinate y at different moments can be calculated. And drawing the obtained (x, y) at different moments 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, i.e. the phase trajectory is in a large scale periodic state, it may be determined that a leak exists in the pipeline. If the fourth signal processing component 042 detects that the phase trajectory is not a periodic trajectory, i.e., the phase trajectory is in a chaotic state, it may be determined that no leakage exists 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 a leak exists in the pipe. 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 pipe.

Alternatively, the fourth signal processing component 042 may also detect the presence or absence of a component of a target frequency in the received electrical signal, wherein the target frequency is located within a specific frequency range, as the pipe leakage may cause the soil surrounding the pipe to vibrate periodically within that 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 the target angular frequency in the first electrical signal; inputting a first signal component of the target angular frequency into a nonlinear system to obtain a first phase track; if the first phase trajectory is a periodic trajectory, it is determined that a component of the first electrical signal at a target frequency corresponding to the target angular frequency is present.

For example, assume that the target frequency to be detected is f ₀ Then the target frequency f ₀ The angular frequency can be expressed as: omega ₀ ＝2πf ₀ . The fourth signal processing component 042 may transform the electrical signal s (t) to be detected on a time axis to obtainThereafter, the fourth signal processing component 042 may add the converted electrical signal +.>And inputting a nonlinear differential equation to obtain a phase track by solving.

If the fourth signal processing component 042 detects that the phase track is a periodic track, i.e. the phase track is in a large scale periodic state, it can be determined that the frequency of existence in the received electrical signal is f ₀ In turn, can determine that there is a leak in the conduit.

In order to achieve reliable detection of pipe leakage, 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 and third electrical signals by the fourth signal processing component 042 may include:

step 101, acquiring an electric signal to be detected.

The fourth signal processing unit 042 is described as an example of analyzing the first electrical signal. Assuming that the sampling frequency of the electrical signal acquired by the first photoelectric acquisition subsystem is 500Hz, the first electrical signal received by the fourth signal processing component 042 within a duration of 150 seconds may be expressed as:

s(t)，t∈{0,0.002,0.004,...,149.998}。

Step 102, determining a target frequency to be detected.

In the embodiment of the present application, it is assumed that the frequency range to be detected is f ₀ To f _n Wherein 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 i-th target frequency f _i With the i-1 th target frequency f _i-1 Can satisfy the following conditions: f (f) _i ＝f _i-1 +Δf。

Alternatively, the fourth signal processing component 042 may be configured to process the signal from the target frequency f ₀ Initially, each target frequency is detected in turn.

By way of example, assume f ₀ ＝10Hz，f _n =100 Hz, Δf=1 Hz, the target frequency first determined by the fourth signal processing component 042 may be 10Hz. After completing the detection of the target frequency of 10Hz, 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 appreciated that the fourth signal processing component 042 may sequentially determine the target frequencies to be detected in order of frequencies from small to large; alternatively, the fourth signal processing component 042 may sequentially determine the target frequency to be detected according to the order of the frequencies from the high frequency to the low frequency; still alternatively, the fourth signal processing component 042 may also randomly select the target frequencies to be detected from the frequency range, only by ensuring that each target frequency within the frequency range can be traversed.

And 103, performing scale conversion 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 a target frequency f to be detected ₀ =10hz, the target frequency can be expressed as ω using an angular frequency ₀ =20pi. The fourth signal processing component 042 may treat the detected electrical signal s ₀ (t) performing scale transformation by adopting a cubic spline interpolation method to obtain

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

Step 105, determining whether the pipeline has leakage according to the phase track.

If the fourth signal processing component 042 detects that the phase trajectory is a periodic trajectory, i.e. the phase trajectory is in a large scale periodic state, it may determine that a leak exists in the pipeline, and perform step 106. If the fourth signal processing component 042 detects that the phase track is not a periodic track, i.e. the phase track is in a chaotic state, it can be determined that the electrical signal does not have a frequency f ₀ And may perform step 108.

Step 106, determining the leakage position.

Optionally, the fourth signal processing component 042 may also determine the location of the pipe leak after determining that the pipe has a leak based on the electrical signal.

In the embodiment of the application, the first photoelectric acquisition subsystem 01 acquires the vibration intensity of the soil around the pipeline through the first pipeline accompanying optical cable 012, the first pipeline accompanying optical cableA pipe-line optical cable 012 corresponds to a plurality of vibration sensors arranged at equal intervals. If the first pipe-accompanied optical cable 012 has a spatial resolution of D and a length of L, the first pipe-accompanied optical cable 012 corresponds toA personal sensor, wherein->Representing a rounding down. The fourth signal processing component 042 may determine the position of the vibration sensor that detected the leak at the first time as the position of the pipe leak when it is determined that the pipe leak exists from the first electrical signal. Wherein the position of the vibration sensor can be calculated from the propagation distance of the first scattered light signal, and the positioning error isWhen the pipeline leaks, rayleigh scattering can occur under the influence of sound vibration when the first laser passes through the vibration sensor at the leakage position. The fourth signal processing component 042 may determine the location of the pipe leak from the time the first scattered light signal from the vibration sensor reaches the first photodetector 013d, and the speed of light. The time at which the scattered light emitted from each sensor reaches the first photodetector 013d is different, so that the positions of the respective vibration sensors can be distinguished. For example, the fourth signal processing component 042 may determine a first time instant at which the first laser 011 emits a first laser light, and a second time instant at which the first photodetector 013d receives a first scattered light signal. The fourth signal processing component 042 may further determine a transmission duration of the first scattered light signal according to the first time and the second time, and determine a position of the pipe leakage according to the duration and the speed of light.

Because the deployment position of each acoustic wave sensor 031 in the acoustic wave acquisition subsystem 03 is determined, when the fourth signal processing component 042 determines that the pipeline has leakage according to the third electrical signal acquired by the acoustic wave acquisition subsystem 03, the position of the acoustic wave sensor 031 that acquires the acoustic wave signal caused by the leakage can be determined asThe location of the pipe leak. Wherein the acoustic wave sensor 031 that collects the acoustic wave signal that enters the large-scale periodic state earliest in 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, whenWhen the positioning error is +.>When->And when the positioning error is + -r.

Step 107, sending an alarm instruction.

The fourth signal processing component 042 may send an alarm command to the alarm component 043 after determining from the electrical signal that a leak exists in the conduit.

Step 108, judging whether the detection of all target frequencies in the frequency range is completed.

The fourth signal processing component 042 determines in step 105 that the frequency f is not present in the electrical signal based on the phase trajectory ₀ And can continue to detect if detection of all target frequencies within the frequency range is complete. If the detection of all the target frequencies in the frequency range is not completed, step 102 may be performed, that is, the fourth signal processing component 042 may determine the next target frequency to be detected, and continue to perform 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, step 101 may be performed, that is, continue to acquire the electrical signal of the next period.

In the embodiment of the present application, the fourth signal processing component 042 may also calculate the amount of change in the temperature around the pipe through the second electrical signal. The rate of change of the temperature of the soil surrounding the pipe due to the change of the ambient temperature is substantially uniform, and the change of the temperature due to the pipe leakage makes the amount of change of the temperature of the soil surrounding the pipe at the leakage position different from other positions. Thus, the fourth signal processing component 042 can determine whether a leak exists in the conduit by detecting a condition of a change in the temperature of the conduit. When the temperature around a pipeline is changed too much, the pipeline can be determined to have leakage.

The fourth signal processing component 042 calculates the amount of change in the temperature around the pipe from the second electrical signal and determines whether a leak exists in the pipe based on the temperature change. Referring to fig. 8, the process of determining whether a leak exists in a conduit by the fourth signal processing component 042 from 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 second electrical signal is received by the fourth signal processing component 042, the temperature variation amount around the pipeline can be determined according to the second electrical signal.

The temperature change around the tube causes deformation of the cable and the second tube accompanies the laser light transmitted in the cable 022, causing brillouin scattering and raman scattering. Wherein the brillouin scattered light has a certain frequency shift with respect to the second laser light (i.e., incident light) emitted by the second laser 021, which is referred to as brillouin frequency shift. The amount of change in the brillouin shift occurring everywhere in the second pipe-concomitant optical cable 022 is linearly dependent on the temperature around the everywhere pipe, and therefore the fourth signal processing component 042 can determine the amount of change in the temperature around the everywhere pipe based on the amount of shift in the received brillouin scattered light.

Alternatively, the second photoelectric acquisition subsystem 02 may determine the brillouin shift in the second pipe companion cable 022 everywhere by means of frequency scanning (simply referred to as frequency sweep). As shown in fig. 3, the second laser light emitted by the second laser 021 is split into two beams of laser light by the beam splitter 023a, one beam of laser light is modulated by the second optical modulator 023b into pulse light and transmitted to the first optical fiber section 022a, and the other beam of laser light is modulated by the electro-optical modulator 023c into continuous light and transmitted to the second optical fiber section 022b, wherein the first optical fiber section 022a and the second optical fiber section 022b belong to the same optical fiber, that is, the pulse light and the continuous light are respectively emitted into the same optical fiber from two ends of the optical fiber. Wherein the pulse light in the optical fiber is subjected to brillouin scattering due to temperature influence. When the pulse light and the continuous light overlap in the second optical companion cable 022, energy transfer occurs between the pulse 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 light waves, the energy transfer occurs when the frequency difference falls within the brillouin frequency shift range, and the brillouin scattering of the pulse light is enhanced, the frequency shift amount of the brillouin scattered light at each place in the second pipeline partner cable 022 can be obtained by scanning the frequency difference between the two beam lasers and the magnitude of the energy transferred at each frequency difference.

Assuming that the second conduit-partner cable 022 has a length of l and a spatial resolution of d, the second conduit-partner cable 022 may be equivalent toA temperature sensor, wherein ∈>Representing a rounding down. The fourth signal processing component 042 may acquire temperatures acquired by 2m+1 temperature sensors with the ith temperature sensor as a center and m×d as a radius. Wherein m is an integer greater than 1, and the fourth signal processing component 042 is at t ₀ The 2m+1 temperatures obtained at the moment can be expressed as:

at t ₀ T after the moment of time ₀ The 2m+1 temperatures obtained at time +Δt can be expressed as:

it should be understood that the 2m+1 temperatures acquired at each of the above-described times may be obtained by the fourth signal processing component 042 from an initial temperature measured in advance and a temperature offset determined based on the frequency shift amount of the brillouin scattered light.

The variation of the temperature acquired by 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 variation.

The average value of the variation Δt of the temperatures acquired by the 2m+1 temperature sensors can be expressed as:

the minimum value of the variation of the temperatures acquired by the 2m+1 temperature sensors can be expressed as:

Step 203, determining whether the temperature around the pipeline is reduced, and determining whether the difference between the average value and the minimum value of the temperature variation is greater than a temperature threshold.

If the fourth signal processing component 042 determines that the temperature around the pipe is decreasing and the difference between the average value and the minimum value of the temperature variation is greater than the temperature threshold, it may determine that the pipe has leakage, and may perform step 204; if the fourth signal processing component 042 determines that the temperature around the pipe does not drop, or that the difference between the average value and the minimum value of the temperature variation is not greater than the temperature threshold, it may determine that there is no leakage in the pipe, and may continue to execute step 201, i.e. may continue to acquire the second electrical signal for the next time period.

For example, assuming a temperature threshold of 2, when the fourth signal processing component 042 detects T _min <0, and |T _min -T _mean |>2, the determination ofThe pipe leaks.

Step 204, determining the leakage position.

The fourth signal processing component 042 may further determine the location of the pipe leak after determining that the pipe has a leak. T (T) _min The corresponding position of the temperature sensor is the position of 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 that The propagation distance of the second scattered light signal may be determined using optical time-domain reflectometry (OTDR) principles.

Optionally, as shown in fig. 4, the leak detection subsystem may further include a data management component 044, the data management component 044 being coupled to the fourth signal processing component 042 for storing historical data and alarm records. The history data may include the electrical signal received by the fourth signal processing component 042, and a processing result (e.g., a phase trajectory) obtained by processing the electrical signal. The data stored in the data management component 044 can be used to perform playback analysis and alarm statistics.

In summary, the embodiment of the application provides a pipeline leakage detection system, which 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 an acoustic wave collection 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 leakage exists in the pipeline according to the state of the phase track, so that the accuracy of pipeline leakage detection is improved.

In addition, the system also obtains the temperature change condition of the pipeline through the leakage detection subsystem according to the second electric signal, so that the detection of pipeline leakage is realized, and whether the pipeline is leaked or not is detected in a plurality of modes, and the reliability of pipeline leakage detection is effectively improved. In addition, as the first photoelectric acquisition system and the second photoelectric acquisition system adopt the pipeline optical cable, the long-distance detection of the pipeline can be realized, and the leakage detection range is effectively improved. And because the detection accuracy of the acoustic wave detection subsystem is higher, the acoustic wave acquisition subsystem can be deployed in a high-result area so as to ensure the accurate detection of the pipeline leakage in the high-result area.

The embodiment of the application provides a pipeline leakage detection method, which can be applied to the leakage detection subsystem 04 in the pipeline leakage detection system provided by the 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 detection method may include:

step 301, a first electrical signal sent by a first photoelectric acquisition subsystem is received, the first electrical signal is converted from a first scattered light signal generated in a first pipeline optical cable, and the first scattered light signal is generated by sound vibration.

Step 302, receiving a second electrical signal sent by a second optical-electrical acquisition subsystem, the second electrical signal being generated from a second scattered light signal generated in a second conduit-side optical cable, and the second scattered light signal being generated from a temperature change.

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

Step 304, 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 according to the sound vibration rule.

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

Step 306, if the pipeline is determined to have leakage, determining the leakage position and sending a warning instruction.

It should be understood that the implementation process of the above steps 301 to 306 may refer to the related description about the fourth signal processing component 042 in the foregoing system embodiment, which is not repeated herein.

It should also be understood that the execution sequence of the steps of the method for detecting a pipeline leakage according to the embodiment of the present application may be adjusted according to the situation, for example, the sequence of step 301, step 302 and step 303 may be exchanged, and step 305 may also precede step 304.

In summary, the embodiment of the application provides a method for detecting leakage of a pipeline, where the leakage detection subsystem may determine a sound vibration rule around the pipeline according to the first electrical signal and the third electrical signal, and detect whether the pipeline has leakage according to the sound vibration rule. The leakage detection subsystem can also acquire the temperature change condition of the pipeline according to the second electric signal, so that the detection of pipeline leakage is realized, and whether the pipeline is leaked or not is detected in a plurality of modes, thereby effectively improving the reliability of pipeline leakage detection.

In the present disclosure, 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" refers to two or more, unless explicitly defined otherwise.

The foregoing description of the exemplary embodiments of the application is not intended to limit the application to the particular embodiments disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the application.

Claims

1. A pipe leak detection system, the pipe leak detection system comprising: the device comprises a first photoelectric acquisition subsystem, a second photoelectric acquisition subsystem, an acoustic wave acquisition subsystem and a leakage detection subsystem;

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 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 according to the temperature change condition;

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;

the first analog-to-digital converter is also connected with the leakage detection subsystem and is used for converting the analog first electric signal into a digital first electric signal and transmitting the digital first electric signal to the leakage detection subsystem;

the second pipeline companion optical cable comprises a first optical fiber section and a second optical fiber section; the second signal processing assembly includes: a beam splitter, a second acoustic optical modulator, an electro-optic modulator, a second filter, a second circulator, a second photodetector, and a second analog-to-digital converter;

2. The pipe leak detection system of claim 1, wherein the first signal processing assembly further comprises: a first acousto-optic modulator and a second amplifier in series between the first laser and the first circulator;

3. The pipe leak detection system of claim 1, wherein the third signal processing assembly comprises: a third analog-to-digital converter, a plurality of third amplifiers, and a plurality of third filters;

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

4. A pipe leak detection system as defined in claim 3, wherein the acoustic wave acquisition subsystem further comprises: a solar cell and a wireless communication assembly;

the wireless communication assembly is respectively connected with the third signal processing assembly and the leakage detection subsystem and is used for transmitting the third electric signal to the leakage detection subsystem.

5. The pipe leak detection system of claim 4, wherein the third signal processing assembly further comprises: a sample holder, a multi-way switch;

the sampling retainers are respectively connected with the third amplifiers and the multi-way switch and are 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.

6. The pipe leak detection system of any one of claims 1 to 5, wherein the leak detection subsystem comprises: a communication component, a fourth signal processing component and an alarm component;

7. The pipe leak detection system of claim 6, wherein the fourth signal processing assembly is configured to:

8. A method of pipe leak detection, for use in a leak detection subsystem in a pipe leak detection system as defined in any one of claims 1 to 7, the method comprising: