An acoustic emission monitoring system and method for nuclear facility equipment failure

Abstract

The present invention relates to the field of nuclear facility monitoring, and in particular to an acoustic emission monitoring system and method for nuclear facility equipment failure. The system comprises: an optical MUX module, an optical modulator, an optical amplifier, an optical circulator, an optical DEMUX module and an optical coherent detector; the optical couplers, optical MUX modules, optical modulators, optical amplifiers, optical circulators, optical DEMUX modules and optical coherent detectors are sequentially connected through optical fibers. The beneficial effect of the present invention is: providing a nuclear facility monitoring system and method with stable and reliable monitoring.

Description

Technical Field

[0001] The invention relates to the field of metal monitoring, and in particular to an acoustic emission monitoring system and method for nuclear facility equipment failure. Background Art

[0002] With the increasing use of nuclear energy, the safety monitoring of nuclear facilities has become a global focus. Monitoring gas leaks in a nuclear radiation environment is an important part of ensuring nuclear safety, because even a small leak can lead to serious consequences, including environmental pollution, personnel health risks, and potential nuclear safety accidents.

[0003] Traditional monitoring methods are often limited in extreme environments, especially the damage of nuclear radiation to electronic equipment and the interference of electromagnetic interference to signal transmission. There is an urgent need for a new, highly reliable and stable monitoring technology. Summary of the invention

[0004] The purpose of the present invention is to provide an acoustic emission monitoring system and method for nuclear facility equipment failures, so as to solve the technical problem that the existing traditional monitoring means are unstable and unreliable for nuclear facility monitoring.

[0005] The present invention provides an acoustic emission monitoring system for nuclear facility equipment failure, comprising:

[0006] Optical coupler, optical MUX module, optical modulator, optical amplifier, optical circulator, optical DEMUX module and optical coherent detector; the optical couplers, optical MUX modules, optical modulator, optical amplifier optical circulator, optical DEMUX module and optical coherent detector are sequentially connected through optical fibers.

[0007] Furthermore, the optical coupler includes two, namely a first optical coupler and a second optical coupler; the lasers of the first optical coupler and the second optical coupler are combined into a beam of light through the optical MUX module.

[0008] Furthermore, the optical coherence detectors also include two corresponding ones, namely a first optical coherence detector and a second optical coherence detector.

[0009] Furthermore, the first optical coherence detector is also connected to the first optical coupler via an optical fiber; and the second optical coherence detector is also connected to the second optical coupler via an optical fiber.

[0010] A method for monitoring acoustic emission of nuclear facility equipment failures, applied to an acoustic emission monitoring system for nuclear facility equipment failures, comprises the following steps:

[0011] S1, two laser signals with different wavelengths and A beam of pulsed light is synthesized through an optical MUX module;

[0012] S2, when the pulse light passes through the optical modulator, optical amplifier, and optical circulator in sequence, the external sound wave causes the optical fiber to deform and excite reverse Rayleigh scattered light. The corresponding Rayleigh scattered light signals are and ;

[0013] S3, wavelength is of and wavelength is of The Rayleigh scattered light is separated by the optical DEMUX module to obtain The reference light, The reference light is coherently superimposed in the first optical coherence detector and the second optical coherence detector to output an acoustic wave signal. and

[0014] Furthermore, the correlation analysis in step S4 uses the Pearson product-moment correlation coefficient or the Spearman rank correlation coefficient.

[0015] Furthermore, in step S4, if the correlation coefficient obtained by the correlation analysis exceeds a preset threshold, the external sound wave is determined to be noise.

[0016] Furthermore, after step S4, voiceprint analysis is performed based on the sound wave monitoring result to obtain the source of the sound wave.

[0017] The beneficial effects provided by the present invention are:

[0018] 1. Dual-wavelength parallel monitoring technology: This patent innovatively uses coarse wavelength division multiplexing (CWDM) technology to simultaneously transmit and process two optical signals of different wavelengths in a single optical fiber. This parallel monitoring method greatly improves the monitoring capability and efficiency of the system, and is particularly suitable for complex and sensitive nuclear radiation environments.

[0019] 2. Strong anti-interference and high adaptability design: By using the correlation analysis between dual-wavelength signals, the system can accurately distinguish between real acoustic emission signals and environmental noise, significantly improving the accuracy of signal recognition. This design gives the system strong anti-interference capabilities, especially suitable for gas leak monitoring in high noise backgrounds.

[0020] 3. Improved radiation resistance: In response to the possible performance degradation of optical fiber materials in nuclear radiation environments, the system effectively reduces the performance degradation of single-wavelength systems caused by radiation by comparing signals of different wavelength channels, thereby enhancing stability and reliability under extreme conditions.

[0021] 4. Highly integrated and intelligent features: The system is not only highly integrated, convenient for remote monitoring and maintenance, but also reduces costs. At the same time, it can be seamlessly combined with advanced signal processing algorithms and artificial intelligence technologies to achieve real-time data analysis, automatic early warning and rapid response, meeting the urgent needs of the nuclear energy industry for intelligent monitoring.

[0022] 5. Accurate event identification capability: Through advanced signal demultiplexing technology and precise correlation analysis methods (such as Pearson product-moment correlation coefficient and Spearman rank correlation coefficient), the system can maintain extremely high sensitivity even in weak signal and high noise environments, accurately identify real acoustic emission events, thereby greatly improving the accuracy of leak detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0024] Figure 2 It is a schematic flow chart of the method of the present invention. DETAILED DESCRIPTION

[0025] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0026] Please refer to Figure 1 , Figure 1 : is a schematic diagram of the system structure of the present invention; the present invention provides an acoustic emission monitoring system for nuclear facility equipment failure, the system specifically includes:

[0027] Optical coupler, optical MUX module, optical modulator, optical amplifier, optical circulator, optical DEMUX module and optical coherent detector; the optical couplers, optical MUX modules, optical modulator, optical amplifier optical circulator, optical DEMUX module and optical coherent detector are sequentially connected through optical fibers.

[0028] It should be noted that the optical coupler includes two, namely a first optical coupler and a second optical coupler; the lasers of the first optical coupler and the second optical coupler are combined into a beam of light through the optical MUX module.

[0029] It should be noted that the optical coherence detectors also include two, namely a first optical coherence detector and a second optical coherence detector.

[0030] It should be noted that the first optical coherence detector is also connected to the first optical coupler via an optical fiber; and the second optical coherence detector is also connected to the second optical coupler via an optical fiber.

[0031] In general, the core of the system is to use CWDM technology to combine two laser signals with different wavelengths ( and ) are combined into a pulsed light through an optical MUX module (optical multiplexer) and injected into the same optical fiber. When this pulsed light propagates in the optical fiber, it not only carries optical information, but is also always ready to capture any traces of acoustic pulsation.

[0032] When the acoustic wave pulse acts on the optical fiber, it causes tiny deformations in the fiber, which stimulates back Rayleigh scattered light.

[0033] This scattered light has the same wavelength as the incident light, so at the output end of the optical fiber, the two wavelengths of scattered light can be easily separated by an optical DEMUX module (optical demultiplexer).

[0034] Next, the scattered light of each wavelength interferes with a portion of the respective incident light, and this interference signal is then sent to a balanced detector for demodulation.

[0035] The demodulated signals are the sound wave signals we need, which correspond to two lasers of different wavelengths.

[0036] To confirm the authenticity of the acoustic event, the system will perform a correlation analysis on the two acoustic signals. The correlation between the two signals can be quantified by calculating the Pearson product-moment correlation coefficient or the Spearman rank correlation coefficient.

[0037] When two signals show a strong correlation, it means that they jointly captured a real sound wave event rather than random noise in a nuclear radiation environment.

[0038] Therefore, the present invention also provides an acoustic emission monitoring method for nuclear facility equipment failure, which is applied to the acoustic emission monitoring system for nuclear facility equipment failure, and comprises the following steps:

[0039] S1, two laser signals with different wavelengths and A beam of pulsed light is synthesized through an optical MUX module;

[0040] It should be noted that the system uses coarse wavelength division multiplexing (CWDM) technology to convert two optical signals of different wavelengths (represented as and ) are injected into the same optical fiber through an optical MUX module (optical multiplexer).

[0041] According to Appendix I "Center Wavelength Spacing and Wavelength Variation" of G.694.2, two standard CWDM wavelength lasers with wavelengths of 1551nm and 1571nm can be selected, with a wavelength offset of ±6.5nm and a protection band width of 7nm. After optical coupler 1 and optical coupler 2 respectively, 90% of the light is usually coupled into the CWDM optical MUX (that is, optical wavelength division multiplexer), and 10% of the light is used as reference light, which interferes with the backscattered signal of Rayleigh scattering and is superimposed on the coherent detector to obtain the acoustic wave signal of the on-site environment.

[0042] S2, when the pulse light passes through the optical modulator, optical amplifier, and optical circulator in sequence, the external sound wave causes the optical fiber to deform and excite reverse Rayleigh scattered light. The corresponding Rayleigh scattered light signals are and ;

[0043] Optical MUX module mixes and The laser light passes through the optical modulator and becomes a pulse light. It then passes through the optical amplifier and the optical circulator and is injected into the sensing optical fiber. When the two wavelengths of light signals propagate in the optical fiber, Rayleigh scattering will occur if there is environmental noise including equipment noise. The scattered light carries the acoustic information along the optical fiber. and The Rayleigh scattered light signals of wavelengths are and ,in Represents time.

[0044] S3, wavelength is of and wavelength is of The Rayleigh scattered light is separated by the optical DEMUX module to obtain The reference light, The reference light is coherently superimposed in the first optical coherence detector and the second optical coherence detector to output an acoustic wave signal. and ;

[0045] It should be noted that acoustic events (such as acoustic waves generated by gas leakage) will cause instantaneous changes in the local physical parameters of the optical fiber (refractive index or length), which will further affect the characteristics of the Rayleigh scattered light, including its intensity and phase. and The optical DEMUX that carries this information and reaches the CWDM optical DEMUX through the optical circulator is the standard demultiplexer of coarse wavelength division multiplexing optical. of and wavelength is of The scattered light is separated by the demultiplexer (DEMUX) and then passes through the optical DEMUX to obtain The reference light, The reference light is coherently superimposed in optical coherence detector 1 and optical coherence detector 2 to output an acoustic wave signal. and .

[0046] S4, performing correlation analysis on the acoustic wave signal to obtain the acoustic wave monitoring result;

[0047] The correlation analysis in step S4 uses the Pearson product-moment correlation coefficient or the Spearman rank correlation coefficient.

[0048] It should be noted that the core of this link is to analyze and The correlation between the two signals is intended to distinguish between real acoustic emission events and various random noises caused by nuclear radiation environment. The correlation between the two signals can be calculated by Pearson product moment correlation coefficient or Spearman rank correlation coefficient:

[0049] Pearson product-moment correlation coefficient formula:

[0050] (1)

[0051] Or the Spearman rank correlation coefficient formula:

[0052] (2)

[0053] in, and They are and The mean of yes Sorting values ​​and The absolute value of the difference between the sorted values, is the number of time points. When two wavelength channels sense the same acoustic event, a high correlation is shown, confirming that the event is a true leakage signal.

[0054] In step S4, if the correlation coefficient obtained by the correlation analysis exceeds a preset threshold, the external sound wave is determined to be noise.

[0055] It should be noted that Based on these calculations, the system sets a threshold that represents the boundary between normal acoustic signals and potential acoustic emission events. The threshold is determined as follows:

[0056] ① Statistical analysis based on historical data: By analyzing a large amount of historical acoustic signal data, the characteristic range of acoustic signals under normal operating conditions can be determined. The threshold can be set to a critical value beyond this normal range to ensure sensitive capture of abnormal acoustic emission events.

[0057] ② Expert evaluation and experience judgment: In the absence of sufficient historical data or when faced with new acoustic emission patterns, the experience and knowledge of industry experts or technicians can be relied upon to evaluate and set appropriate thresholds.

[0058] ③ Real-time adjustment and optimization: The threshold is not static. In actual operation, the system can be dynamically adjusted according to the feedback of real-time monitoring data to optimize the threshold setting and improve the accuracy and sensitivity of acoustic emission event detection.

[0059] After step S4, voiceprint analysis is performed based on the sound wave monitoring results to obtain the source of the sound wave.

[0060] As an example, after an acoustic emission event is identified, performing voiceprint analysis on the extracted Rayleigh scattering signal is an advanced analytical method to deepen the understanding of the source and nature of the signal.

[0061] ① Standardization: In order to facilitate cross-signal comparison, the signal needs to be standardized and its amplitude and frequency range adjusted to ensure that the signals collected at different times or locations are comparable under a unified scale.

[0062] ② Feature extraction: Through analysis, the basic features of the signal such as pitch, timbre, loudness, etc. are extracted. These features reflect the physical properties and acoustic characteristics of the signal. Spectral analysis is also performed, such as using fast Fourier transform (FFT) and other technologies to convert the time domain signal to the frequency domain, analyze the energy distribution of different frequency bands, and reveal the spectral characteristics of the signal, such as resonance peaks, fundamental frequencies and overtones, as well as spectrograms, cepstrum, mel spectrum, etc. These are key indicators for distinguishing the characteristics of different sound sources.

[0063] ③ Model training and matching process, including voiceprint library construction, to establish a database containing known sound source samples, each with its own unique acoustic features. Machine learning models, such as Gaussian mixture model (GMM), support vector machine (SVM) or deep learning network, are used to train with data in the voiceprint library to learn the characteristic patterns of different sound sources. Feature matching is then performed: the features of the signal to be identified are compared with the features in the voiceprint library to find the best matching voiceprint record to identify the source of the signal.

[0064] ④ Result analysis and judgment: The judgment standard is to determine the signal attribution based on the degree of match. A high degree of match means successful identification of a specific individual or sound source; conversely, additional data collection or model optimization may be required to improve recognition accuracy. Post-processing and verification: Detailed evaluation of the recognition results, such as ensuring the reliability of the results through confidence scoring. In the case of high uncertainty, other sensor data or manual review can be combined to further improve the accuracy and reliability of the final recognition.

[0065] In summary, the beneficial effects of the present invention are:

[0066] 1. Dual-wavelength parallel monitoring technology: This patent innovatively uses coarse wavelength division multiplexing (CWDM) technology to simultaneously transmit and process two optical signals of different wavelengths in a single optical fiber. This parallel monitoring method greatly improves the monitoring capability and efficiency of the system, and is particularly suitable for complex and sensitive nuclear radiation environments.

[0067] 2. Strong anti-interference and high adaptability design: By using the correlation analysis between dual-wavelength signals, the system can accurately distinguish between real acoustic emission signals and environmental noise, significantly improving the accuracy of signal recognition. This design gives the system strong anti-interference capabilities, especially suitable for gas leak monitoring in high noise backgrounds.

[0068] 3. Improved radiation resistance: In response to the possible performance degradation of optical fiber materials in nuclear radiation environments, the system effectively reduces the performance degradation of single-wavelength systems caused by radiation by comparing signals of different wavelength channels, thereby enhancing stability and reliability under extreme conditions.

[0069] 4. Highly integrated and intelligent features: The system is not only highly integrated, convenient for remote monitoring and maintenance, but also reduces costs. At the same time, it can be seamlessly combined with advanced signal processing algorithms and artificial intelligence technologies to achieve real-time data analysis, automatic early warning and rapid response, meeting the urgent needs of the nuclear energy industry for intelligent monitoring.

[0070] 5. Accurate event identification capability: Through advanced signal demultiplexing technology and precise correlation analysis methods (such as Pearson product-moment correlation coefficient and Spearman rank correlation coefficient), the system can maintain extremely high sensitivity even in weak signal and high noise environments, accurately identify real acoustic emission events, thereby greatly improving the accuracy of leak detection.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An acoustic emission monitoring system for nuclear facility equipment failure, characterized in that: include: Optical couplers, optical MUX modules, optical modulators, optical amplifiers, optical circulators, optical DEMUX modules and optical coherence detectors; The optical coupler, the optical MUX module, the optical modulator, the optical amplifier optical circulator, the optical DEMUX module, and the optical coherence detector are sequentially connected through optical fibers; The optical coupler includes two, namely a first optical coupler and a second optical coupler; the lasers of the first optical coupler and the second optical coupler are combined into a beam of light through an optical MUX module; The optical coherence detectors also include two corresponding ones, namely a first optical coherence detector and a second optical coherence detector; The first optical coherence detector is also connected to the first optical coupler via an optical fiber; the second optical coherence detector is also connected to the second optical coupler via an optical fiber; The system principle is as follows: Two laser signals of different wavelengths and A pulse light is synthesized by the optical MUX module; when the pulse light passes through the optical modulator, optical amplifier, and optical circulator in sequence, the external sound wave causes the optical fiber to deform and excite the reverse Rayleigh scattered light. The corresponding Rayleigh scattered light signals are and ; The wavelength is of and wavelength is of The Rayleigh scattered light is separated by the optical DEMUX module to obtain The reference light, The reference light is coherently superimposed in the first optical coherence detector and the second optical coherence detector to output an acoustic wave signal. and ; Carry out correlation analysis on the acoustic wave signal to obtain the acoustic wave monitoring results.

2. A method for acoustic emission monitoring of nuclear facility equipment failure, applied to the acoustic emission monitoring system for nuclear facility equipment failure as claimed in claim 1, characterized in that: The method comprises the following steps: S1, two laser signals with different wavelengths and A beam of pulsed light is synthesized through an optical MUX module; S2, when the pulse light passes through the optical modulator, optical amplifier, and optical circulator in sequence, the external sound wave causes the optical fiber to deform and excite reverse Rayleigh scattered light. The corresponding Rayleigh scattered light signals are and ; S3, wavelength is of and wavelength is of The Rayleigh scattered light is separated by the optical DEMUX module to obtain The reference light, The reference light is coherently superimposed in the first optical coherence detector and the second optical coherence detector to output an acoustic wave signal. and ; S4. Perform correlation analysis on the acoustic wave signal to obtain the acoustic wave monitoring result.

3. The method for acoustic emission monitoring of nuclear facility equipment failure according to claim 2, characterized in that: The correlation analysis in step S4 uses the Pearson product-moment correlation coefficient or the Spearman rank correlation coefficient.

4. The method for acoustic emission monitoring of nuclear facility equipment failure according to claim 2, characterized in that: In step S4, if the correlation coefficient obtained by the correlation analysis exceeds a preset threshold, the external sound wave is determined to be noise.

5. The method for acoustic emission monitoring of nuclear facility equipment failure according to claim 4, characterized in that: The preset threshold is determined by a statistical analysis method based on historical data or an expert evaluation method, and the threshold is dynamically adjusted according to feedback from real-time monitoring data.

6. The method for acoustic emission monitoring of nuclear facility equipment failure according to claim 2, characterized in that: After step S4, voiceprint analysis is performed based on the sound wave monitoring results to obtain the source of the sound wave.

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