Monitoring, prevention and control system and method for filling and pipe blocking

Abstract

The invention relates to a monitoring, prevention and control system for filling and pipe plugging, which comprises a ground integrated console, a distributed optical fiber acoustic monitoring system, a pressure detection mechanism and a discharge mechanism, and is characterized in that the ground integrated console is electrically connected with the distributed optical fiber acoustic monitoring system, the pressure detection mechanism and the discharge mechanism through a communication system, and data connection is established; at least one distributed optical fiber acoustic monitoring system and at least one pressure detection mechanism are connected with the pipe wall of the filling pipeline and distributed in the axis direction of the filling pipeline, and the discharging mechanism is connected with the filling pipeline. The use method comprises the following four steps: optical fiber laying, system operation flow, pipe blockage judgment and active prevention and control, and mechanism maintenance. Precise positioning of the pipe blocking position can be achieved, the pipe blocking area is determined in combination with the acoustic signal spatio-temporal evolution law, active regulation and control of filling and pipe blocking are achieved through the pressure release valve and the vibration ring, the problem of response lag caused by traditional manual troubleshooting or single-parameter triggering is solved, and the timeliness of field emergency disposal is improved.

Description

Technical Field

[0001] This invention relates to a monitoring system, specifically a monitoring and control system for filling and blocking pipes and its detection method. Background Technology

[0002] Backfilling is a green method for disposing of multi-source solid waste in mines, but blockage of backfilling pipelines is a core problem restricting the safety and efficiency of mine backfilling. Abnormal slurry flow within the backfilling pipeline (such as sudden changes in flow velocity, particle deposition, or local siltation) can cause a sudden increase in pressure and flow instability, leading to pipe blockage or even pipe rupture. Such accidents not only affect the quality of backfilling connection to the roof and exacerbate the risk of overburden instability, but also trigger secondary geological disasters, hindering the large-scale application of backfilling technology.

[0003] While existing technologies for controlling pipe blockage during filling operations attempt to capture abnormal signals through acoustic monitoring, these methods often rely on discrete acoustic sensors or local vibration probes, resulting in large monitoring blind spots and low signal sensitivity. For example, single-point signals are easily affected by environmental noise, leading to inaccurate extraction of blockage features and difficulty in distinguishing between actual blockages and transient flow fluctuations in the filling pipeline. Furthermore, existing systems often process acoustic signals based on single thresholds, lacking multi-parameter correlation analysis of acoustic wave frequency energy, pipeline deformation, and slurry flow velocity, resulting in high false alarm rates and large location errors. Additionally, while some automated assembly devices in existing unloading systems can trigger pressure relief operations, the lack of dynamic tracking of the spatiotemporal evolution of acoustic signals prevents rapid determination of blockage location and diffusion trends, leading to insufficiently targeted control measures.

[0004] Therefore, there is an urgent need to develop a fiber optic acoustic monitoring system for the entire filling pipeline. This system would form a continuous sensing network by deploying fiber optic sensors to capture the acoustic characteristics (such as frequency-division energy distribution) caused by abnormal slurry flow in real time. Combined with multi-parameter correlation, it would achieve precise location of blockages, enable proactive control of filling and pipe blockage, and improve the accuracy of pipe blockage early warning and the timeliness of emergency response. Summary of the Invention

[0005] The purpose of this invention is to provide a monitoring and control system for filling and blocking pipes, as well as a method for using it.

[0006] To achieve the above objectives, the present invention provides a monitoring and control system and method for filling and blocking pipes: A monitoring and prevention and control system for filling pipe blockage, comprising a ground integrated console, a distributed fiber optic acoustic monitoring system, a pressure detection mechanism and a discharging mechanism. The ground integrated console is electrically connected to the distributed fiber optic acoustic monitoring system, the pressure detection mechanism and the discharging mechanism respectively through a communication system and establishes a data connection. There is at least one distributed fiber optic acoustic monitoring system and at least one pressure detection mechanism, which are connected to the wall of the filling pipe and distributed along the axis direction of the filling pipe. There are several discharging mechanisms, which are connected to the filling pipe and distributed along the axis direction of the filling pipe, and the distance between adjacent two discharging mechanisms is 9 - 15 meters.

[0007] Further, the discharging mechanism includes a discharging device, a vibration ring and a detection sensor group. The discharging device is located inside the filling pipe and is connected to the inner side surface at the bottom of the filling pipe. At the same time, the discharging device is located on the front side of the vibration ring along the axis direction of the filling pipe, and the detection sensor group is connected to the wall of the filling pipe and is located between the discharging device and the vibration ring. The discharging device, the vibration ring and the detection sensor group are all connected to the ground integrated console.

[0008] Further, the discharging device includes a discharge filter plate, an adjustment seat and a movable turntable. The adjustment seat is of a ring structure, and a through hole is provided at the corresponding filling pipe wall. The through hole is coaxially distributed with the adjustment seat, and its axis intersects and is perpendicular to the axis of the filling pipe. The discharge filter plate is embedded in the adjustment seat and is slidably connected to the adjustment seat through the movable turntable to block the through hole. At the same time, the movable turntable is electrically connected to the ground integrated console.

[0009] Further, the vibration ring includes an exciter, an elastic cushion block, a positioning base, a bearing spring and an ultrasonic oscillation mechanism. There are two positioning bases in total, both of which are arc-shaped groove structures with a cross-section in the shape of "凵", and the two positioning bases are connected by bolts and form a closed ring structure coaxially distributed with the filling pipe. There are at least two elastic cushion blocks, which are evenly distributed around the axis of the filling pipe. One end of each elastic cushion block abuts against the surface of the filling pipe, and the other end is connected to a bearing spring and is coaxially distributed with the bearing spring. The axis of the elastic cushion block intersects and is perpendicular to the axis of the filling pipe. At the same time, the bearing spring is also connected to the bottom of the groove on the inner side surface of the positioning base. In addition, an ultrasonic oscillation mechanism coaxially distributed with each elastic cushion block is provided inside each elastic cushion block. There is at least one exciter, which is connected to the outer side surface of the positioning base, and the vibration direction of the exciter forms an angle of 0° - 90° with the vibration direction of the ultrasonic oscillation mechanism. The exciter and the ultrasonic oscillation mechanism are both electrically connected to the ground integrated console.

[0010] Furthermore, the distributed fiber optic acoustic monitoring system includes a single-mode armored optical cable, a distributed fiber optic acoustic sensing mechanism, and a measurement and control and signal processing mechanism. The single-mode armored optical cable is laid along the upper part of the filling pipe and is distributed parallel to the pipe's axis. Several distributed fiber optic acoustic sensing mechanisms are distributed along the filling pipe's axis and connected to the single-mode armored optical cable, while also being connected to the measurement and control and signal processing mechanism. The measurement and control and signal processing mechanism is connected to a ground-based integrated control console. The distributed fiber optic acoustic sensing mechanism includes a light pulse generation module, a light intensity detection module, and a fiber optic circulator. The light pulse generation module is connected to the single-mode armored optical cable on one hand and to the fiber optic circulator on the other hand through the light intensity detection module. The fiber optic circulator and the light intensity detection module are connected to the measurement and control and signal processing mechanism, and the measurement and control and signal processing mechanism is connected to the ground-based integrated control console via a communication system.

[0011] Furthermore, the optical pulse generation module includes a narrow linewidth laser, an optical fiber coupler, an acousto-optic modulator, and an erbium-doped fiber amplifier. The narrow linewidth laser is connected to the optical fiber coupler, and the first output end of the optical fiber coupler is connected to the first input end of the optical quantity detection module, while the second output end is connected to the first input end of the acousto-optic modulator. The acousto-optic modulator is also connected to the erbium-doped fiber amplifier. The erbium-doped fiber amplifier is connected to an optical fiber circulator.

[0012] Furthermore, the light quantity detection module includes a polarization diversity receiver and a photodetector, wherein the first output end of the fiber coupler is connected to the input end of the polarization diversity receiver, and the second output end is connected to the input end of the acousto-optic modulator; the output end of the acousto-optic modulator is connected to the input end of the erbium-doped fiber amplifier, and the output end of the erbium-doped fiber amplifier is connected to a circulator.

[0013] Furthermore, the pressure detection mechanism includes a power module, a data acquisition card, a filling parameter master station, a pressure sensor, and an electronic concentration meter. Each of the pressure sensor and the electronic concentration meter has at least one component and is connected to the inner side of the outer wall of the filling pipeline. Simultaneously, the pressure sensor and the electronic concentration meter are electrically connected to the power module and the data acquisition card, and the power module and the data acquisition card are electrically connected to the filling parameter master station. The filling parameter master station also establishes a data connection with the ground-based integrated control console.

[0014] A method for using a monitoring and control system for filling and blocking pipes includes the following steps: S1, Fiber optic cable laying steps: Lay single-mode armored optical cable directly above the axis of the filling pipe, and fix it with pre-tension clamps every 10 m to ensure that the optical cable is tightly attached to the pipe wall.

[0015] S2, System Operation Flow: After startup, the system updates the acoustic frequency distribution energy distribution, pipe deformation diagram, and slurry flow velocity diagram of the filling pipe every 5 seconds, and calculates and identifies the slurry blockage location in each area; S3, Pipe Blockage Detection and Active Prevention: The ground-based integrated control console calculates the full-range acoustic frequency division energy, pipeline deformation, and slurry flow velocity based on real-time data. When any two of these three exceed the limit, a first-level pressure relief is triggered, and the unloading system is started. If the exceeding item does not return to a safe value within 10 seconds, a second-level pressure relief is initiated, and a manual intervention mode is triggered. After the pipe blockage is cleared, the system automatically records the fault parameters, optimizes the threshold library, and generates an operation and maintenance report.

[0016] S4, Maintenance Mechanism: Daily optical cable link attenuation test is performed, and a self-test program is triggered when the loss fluctuation is >0.2 dB; every quarter, acoustic energy calibration is performed by applying a standard vibration signal through an exciter to determine the mapping coefficient.

[0017] Furthermore, in steps S2 and S3, when calculating and identifying the location of blockage in the filling grout in each region, calculating the overall acoustic frequency division energy of the pipeline, pipeline deformation, and grout flow velocity, data processing is performed according to the following steps: Step 1: Preprocess the collected acoustic data using the variable step size least mean square algorithm; specific implementation process: (1) Initialization: Set the initial weight vector w(0)=0; The initial step size factor μ0 is typically set to 0.01 - 0.1. The error threshold ξ is used for step size adjustment; Iteration count k=1; (2) For the k-th iteration: Calculate the error between the desired signal and the actual output: e(k) = d(k) - x(k)Tw(k-1); Where d(k) is the reference signal; x(k) is the input acoustic data vector at time k; Dynamically adjust the step size factor: update the step size μ(k) according to the error magnitude. A commonly used adjustment formula is: Update the weight vector: w(k) = w(k-1) + μ(k)e(k)x(k); Let k = k + 1, and repeat step 2 until the iteration ends or the error converges to the preset range; Step 2: Based on the data processed in Step 1, empirical mode decomposition combined with energy detection is used to divide the acoustic wave frequency energy. Empirical Mode Decomposition (EMD) does not require preset basis functions and can adaptively decompose non-stationary acoustic signals into a series of Intrinsic Mode Functions (IMFs). Each IMF corresponds to a signal component at a different frequency scale. Combined with energy detection, it can accurately extract the frequency domain features of choking echoes, compensating for the insufficient adaptability of wavelet transform to non-stationary signals. The implementation process is as follows: (1) Signal preprocessing: The noise-reduced acoustic signal output in step 1 is subjected to extreme point detection to remove abnormal pulse interference; (2) Empirical Mode Decomposition: Identify the local maxima and minima of the signal, fit the upper and lower envelopes using cubic spline interpolation, and calculate the mean value m1(t) of the envelopes; Extract the first intrinsic mode function IMF1(t) = s(t) - m1(t). If IMF1(t) satisfies the conditions of intrinsic mode function (the number of extreme points and zero crossings are equal or differ by 1, and the average value of the upper and lower envelopes is 0), then separate the component; otherwise, repeat the above process with IMF1(t) as a new signal until all IMF components are obtained. The remaining signal is the residual component r(t), which represents the trend term of the signal; (3) Frequency division energy calculation: Perform Hilbert transform on each IMF component to obtain the instantaneous frequency and instantaneous amplitude, and calculate the energy of each IMF. ; (4) Blocking echo identification: Analyze the energy distribution of each IMF. Blocking echoes usually show energy abrupt changes in a specific IMF component. Combine the residual components to locate the time position of the echo. Analysis and calculation process of acoustic wave frequency division energy data and pipeline deformation data: Calculating the frequency-divided energy of sound waves requires combining signal processing theory with acoustic characteristics. The sound waves are decomposed into different frequency components through frequency domain analysis, and the energy of each frequency band is calculated. The following are the detailed theoretical basis and calculation steps: Time-domain representation of sound waves Sound waves can be represented as time-domain signals p(t), where p is the sound pressure and t is time; the total energy E of the sound wave is defined in the time domain as... Where Z is the characteristic impedance of the dielectric. Frequency domain transformation: Fourier transform; The time-domain signal is converted into the frequency-domain spectrum P(f) by Fourier transform, satisfying: ; According to Parseval's theorem, the energy in the time domain is equal to the energy in the frequency domain: ; Where is the power spectral density, representing the energy per unit frequency; Frequency division energy calculation steps (1) Define the frequency band range: For example, divide it into M frequency bands [flow,i, fhigh,i] (i=1,2,…,M); (2) Integrate the power spectral density over each frequency band: ; in, =fs / N; Frequency division energy characterizes the blocked area. Based on the calculated frequency division energy of each frequency band, the higher the energy, the higher the probability of pipe blockage; combined with the starting position of the initial armored optical cable, the pipe blockage location can be located in the frequency domain. Calculate the deformation of the filling pipe (1) Sound pressure (p) is the fluctuation of medium pressure during sound wave propagation, and its relationship with stress (σ) is: p ~ σ; (2) According to Hooke's Law, the relationship between stress and strain is: σ = K⋅ε. For sound waves, the relationship between bulk modulus and medium density (ρ) and wave velocity (c) is: K = ρc 2 ; (3) ε=p / K, that is, if the sound pressure amplitude P is known, then the strain amplitude is: ε=P / ρc 2 ; (4) ε = ΔL / L, where ΔL is the pipe deformation and L is the pipe circumference; Pipe deformation characterizes the blocked area The deformation of the filling pipe for each frequency band is calculated. The greater the deformation, the higher the probability of pipe blockage. Combined with the starting position of the initial armored optical cable, the location of the blockage is located in the frequency domain. Analysis and calculation process of slurry flow velocity data: In a filled pipe (full pipe flow), the relationship between fluid pressure and velocity can be derived from the basic principles of fluid mechanics and the law of conservation of energy, but it needs to be calculated in conjunction with Bernoulli's equation. For incompressible steady flow, the energy conservation equation along the streamline is: ; Where p is the fluid pressure (Pa) and ρ is the fluid density (kg / m³). 3 g is the acceleration due to gravity (m / s²). 2 v is the average fluid velocity (m / s), z is the position height (m), and C is a constant. Slurry flow velocity characterizes the blocked pipe area Based on the test data from the pressure sensor and the relationship between pressure and flow rate in Bernoulli's equation, the higher the pressure and the lower the flow rate, the higher the degree of pipe blockage. Combined with the initial injection position of the filling slurry, the location of the blockage can be determined.

[0018] Compared with existing technologies, this invention, on the one hand, constructs a distributed fiber optic acoustic sensing network by laying single-mode armored optical cables along the upper part of the entire filling pipeline. Through the elastic-optical effect, it demodulates the acoustic data of the entire pipeline in real time, establishing a multi-parameter correlation analysis of the full-domain acoustic frequency-division energy distribution, pipeline deformation, and slurry flow velocity to accurately locate the blockage. On the other hand, based on the multi-parameter correlation analysis of the filling pipeline and combined with the spatiotemporal evolution of acoustic signals, it determines the blockage area and actively controls the filling blockage through pressure relief valves and vibration rings. This solves the problem of response lag in traditional manual inspections or single-parameter triggering, improving the timeliness of on-site emergency response. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the system structure of the present invention; Figure 2 A partial cross-sectional structural diagram of the installation structure for the discharge mechanism; Figure 3 This is a partial structural diagram of a distributed fiber optic acoustic monitoring system. Figure 4 A schematic diagram of a partial installation structure for a pressure testing mechanism; Figure 5 Here is the logic block diagram of the ground integrated control system; Figure 6 This is a schematic diagram of the core processor's principle structure; Figure 7 A schematic diagram of the operating principle and structure of the core control system for filling; Figure 8 This is a schematic diagram illustrating the operating principle and structure of a distributed fiber optic acoustic monitoring system. Figure 9 This is a schematic diagram of the method flow of the present invention; Figure 10 The acoustic frequency distribution, slurry flow velocity diagram, and deformation diagram are used to fill the pipeline. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figures 1-8A monitoring and control system for filling pipe blockage includes a ground integrated control console 1, a distributed fiber optic acoustic monitoring system 2, a pressure detection mechanism 3, and a material release mechanism 4. The ground integrated control console 1 is electrically connected to the distributed fiber optic acoustic monitoring system 2, the pressure detection mechanism 3, and the material release mechanism 4 via a communication system, and establishes a data connection. There is at least one distributed fiber optic acoustic monitoring system 2 and pressure detection mechanism 3, which are connected to the wall of the filling pipe and distributed along the axis of the filling pipe. Several material release mechanisms 4 are connected to the filling pipe, distributed along the axis of the filling pipe, and the distance between two adjacent material release mechanisms 4 is 9-15 meters.

[0022] In this embodiment, the discharge mechanism 4 includes a discharge mechanism 41, a vibration ring 42, and a detection sensor group 43. The discharge mechanism 41 is located inside the filling pipe and is connected to the inner side of the bottom of the filling pipe. The discharge mechanism 41 is located on the side in front of the vibration ring 42 along the axis of the filling pipe. The detection sensor group 43 is connected to the wall of the filling pipe and is located between the discharge mechanism 41 and the vibration ring 42. The discharge mechanism 41, the vibration ring 42, and the detection sensor group 43 are all connected to the ground integrated control console 1.

[0023] The unloading mechanism 41 includes a discharge filter plate 411, an adjusting seat 412, and a movable turntable 413. The adjusting seat 412 has an annular structure and a through hole 414 is provided on the wall of the corresponding filling pipe. The through hole 414 is coaxially distributed with the adjusting seat, and its axis intersects and is perpendicular to the axis of the filling pipe. The discharge filter plate 411 is embedded in the adjusting seat 412 and is slidably connected to the adjusting seat 412 through the movable turntable 413, which blocks the through hole 414. The movable turntable 413 is electrically connected to the ground integrated control console 1.

[0024] As a further optimization, a control valve 415 is provided at the through hole 414.

[0025] Meanwhile, the vibration ring 42 includes an exciter 421, elastic cushion blocks 422, positioning bases 423, bearing springs 424, and an ultrasonic oscillation mechanism 425. There are two positioning bases 423 in total, both of which are arc-shaped groove structures with a "U" - shaped cross-section. The two positioning bases 423 are connected by bolts and form a closed ring structure coaxial with the filling pipeline. There are at least two elastic cushion blocks 422, which are evenly distributed around the axis of the filling pipeline. One end of each elastic cushion block 422 abuts against the surface of the filling pipeline, and the other end is connected to a bearing spring 424 and is coaxially distributed with the bearing spring 424. The axis of the elastic cushion block 422 intersects and is perpendicular to the axis of the filling pipe. At the same time, the bearing spring 424 is also connected to the bottom of the groove on the inner side of the positioning base 423. In addition, an ultrasonic oscillation mechanism 425 coaxial with each elastic cushion block 422 is provided inside each elastic cushion block 422. There is at least one exciter 421, which is connected to the outer side of the positioning base 423, and the vibration direction of the exciter 421 forms an angle of 0° - 90° with the vibration direction of the ultrasonic oscillation mechanism 425. The exciter 421 and the ultrasonic oscillation mechanism 425 are both electrically connected to the ground integrated console 1.

[0026] It should be emphasized that the distributed fiber optic acoustic monitoring system 2 includes a single - mode armored optical cable 21, a distributed fiber optic acoustic sensing mechanism 22, and a measurement, control, and signal processing mechanism 23. Among them, the single - mode armored optical cable 21 is arranged along the upper part of the filling pipeline and is parallel to the axis direction of the filling pipeline. There are several distributed fiber optic acoustic sensing mechanisms 22, which are distributed along the axis of the filling pipe and are connected to the single - mode armored optical cable 21, and are also connected to the measurement, control, and signal processing mechanism 23 at the same time. The measurement, control, and signal processing mechanism 23 is connected to the ground integrated console 1. Among them, the distributed fiber optic acoustic sensing mechanism 22 includes an optical pulse generation module 221, an optical quantity detection module 222, and an optical fiber circulator 223. Among them, the optical pulse generation module 221 is connected to the single - mode armored optical cable 21 on the one hand, and is connected to the optical fiber circulator 223 through the optical quantity detection module 222 on the other hand. The optical fiber circulator 223, the optical quantity detection module 222, and the measurement, control, and signal processing mechanism 23 are connected, and the measurement, control, and signal processing mechanism 23 and the ground integrated console 1 are connected through a communication system.

[0027] In addition, the optical pulse generation module 221 includes a narrow - line - width laser 2211, an optical fiber coupler 2212, an acousto - optic modulator 2213, and an erbium - doped fiber amplifier 2214. Among them, the narrow - line - width laser 2211 is connected to the optical fiber coupler 2212. At the same time, the first output end of the optical fiber coupler 2212 is connected to the first input end of the optical quantity detection module 222, and the second output end is connected to the first input end of the acousto - optic modulator 2213. At the same time, the acousto - optic modulator 2213 is connected to the erbium - doped fiber amplifier 2214. The erbium - doped fiber amplifier 2214 is connected to the optical fiber circulator 223.

[0028] Furthermore, the light quantity detection module 222 includes a polarization diversity receiver 2221 and a photodetector 2222, wherein the first output end of the fiber coupler 2221 is connected to the input end of the polarization diversity receiver 2221, and the second output end is connected to the input end of the acousto-optic modulator 2213; the output end of the acousto-optic modulator 2213 is connected to the input end of the erbium-doped fiber amplifier, and the output end of the erbium-doped fiber amplifier is connected to a circulator.

[0029] The distributed fiber optic acoustic monitoring system set up in this system is the core component of the monitoring system, responsible for detecting acoustic signals. Its main components include: an optical pulse generation module, an optical quantity detection module, and a circulator. Specifically, the optical pulse generation module includes: a narrow-linewidth laser, an optical fiber coupler, an acousto-optic modulator, and an erbium-doped fiber amplifier. The functions of each part are as follows: the narrow-linewidth laser is used to emit highly stable narrow-linewidth laser light as the light source for the sensing system. Its output end is connected to the input end of the fiber coupler to ensure efficient transmission of optical signals. The fiber coupler splits the optical signal emitted by the narrow-linewidth laser into two paths: the first output end is connected to the first input end of the optical quantity detection module to detect changes in the intensity of the optical signal; the second output end is connected to the first input end of the acousto-optic modulation module to modulate the laser emitted by the narrow-linewidth laser into a linearly swept frequency optical pulse, which is then output to the erbium-doped fiber amplifier. The acousto-optic modulator uses radio frequency signals to modulate the narrow-linewidth laser emitted by the narrow-linewidth laser into a linearly swept frequency optical pulse, which is then used to modulate the light emitted by the laser into a linearly swept frequency optical pulse signal through gating and output to the erbium-doped fiber amplifier. The erbium-doped fiber amplifier amplifies the power of the optical pulse output from the acousto-optic modulation module and injects it into the single-mode logging steel fiber through a circulator. The fiber circulator is used to separate the transmitted optical signal and the received reflected signal. Transmitter: The high-power optical pulse output from the erbium-doped fiber amplifier in the optical pulse generation module enters through the first port of the circulator, exits from the second port, and is transmitted to the sensing fiber. Receiver: The reflected signal returned from the sensing fiber enters through the second port of the circulator, exits from the third port, and is transmitted to the polarization diversity receiver of the optical quantity detection module. The photodetector module includes a polarization diversity receiver and a balanced photodetector. The functions of each part are as follows: The mixed optical signal of the local optical pulse output from the fiber coupler and the reflected light enters the polarization diversity receiver. The polarization diversity receiver decomposes the mixed optical signal into two orthogonal polarization components: a horizontal polarization component and a vertical polarization component. The two decomposed polarization components are phase-adjusted by optical phase delayers to ensure the stability of the subsequent interference signal. The two phase-adjusted polarization components interfere with the reference optical signal, and the interfering optical signals are transmitted to the input terminals of two photodetectors. The photodetectors convert the received interference optical signal into an electrical signal and output it to the ADC input terminal of the measurement and control and signal processing system via a coaxial cable.

[0030] Meanwhile, the pressure detection mechanism 3 includes a power module 31, a data acquisition card 32, a filling parameter master station 33, a pressure sensor 34, and an electronic concentration meter 35. Each of the pressure sensor 34 and the electronic concentration meter 35 has at least one component and is connected to the inner side of the outer wall of the filling pipeline. The pressure sensor 34 and the electronic concentration meter 35 are electrically connected to the power module 31 and the data acquisition card 32. The power module 31 and the data acquisition card 32 are also electrically connected to the filling parameter master station 33. The filling parameter master station 33 establishes a data connection with the ground integrated control console 1.

[0031] The functions of each component in the pressure detection mechanism are as follows: The functions of each part are as follows: the power supply module adopts a wide-voltage input isolated power supply with dual-channel voltage regulation to power the sensors and data acquisition card, and integrates overcurrent / overvoltage protection functions; the pressure sensor adopts a corrosion-resistant ceramic piezoresistive sensor, which is installed on the outer wall of the filling pipe through a flange to detect the slurry flow status in real time; the electronic concentration meter adopts a non-contact microwave concentration sensor and outputs a signal to the data acquisition card; the data acquisition card adopts a 16-bit high-precision ADC, integrating anti-aliasing filtering and temperature compensation algorithms, and uploads frequency division energy data, pipe deformation data, and slurry flow velocity data to the filling parameter master station; the filling parameter master station is used to receive and store acoustic energy spectrum data, pipe deformation data, and slurry flow velocity data, interact with the core processor, and update the slurry flow parameter library in real time.

[0032] In a further optimized configuration, the ground-based integrated control console 1 includes, but is not limited to, a core processor, a web server, an audible and visual alarm system, and sensors. Wherein: The distributed acoustic monitoring system and pressure sensor system acquire real-time data on the full-domain frequency division energy, pipe deformation, and slurry flow velocity of the filling pipe via armored mining optical cables and filling pipe pressure, respectively, and transmit them to the core processor. The core processor analyzes the monitoring data for any abnormal features and locates the abnormal features. The web server is connected to the core processor and displays the data processing results sent by the core processor to the web server for display on a "single map," as well as the location of the filling pipe blockage. After receiving the blockage signal through the communication network, the alarm unit issues audible, visual, and vibration alarms.

[0033] The core processor system includes an acoustic sensor A / D acquisition and control module, a pressure sensor A / D acquisition and control module, a data bus, three SRAM interface modules, a variable step size minimum mean square algorithm filter processing module, an empirical mode decomposition combined with energy detection processing module, a frequency division energy calculation module, a pipeline deformation calculation module, a slurry flow velocity calculation module, a filling pipeline positioning calculation module, a core microcontroller, three I / O pins, a system clock, RAM storage, a power supply, etc. Figure 7The acoustic wave sensor A / D acquisition and control module is a core processor pin used to connect to the output signal of the external acoustic wave amplifier circuit, inputting the amplified analog acoustic wave signal into the core processor to convert it into a digital signal. The pressure sensor A / D acquisition and control module is a core processor pin used to connect to the output signal of the external pressure amplifier circuit, inputting the amplified analog pressure signal into the core processor to convert it into a digital signal. The core microprocessor is responsible for handling various information processing tasks, including acoustic wave and pressure signal analysis, signal processing, and algorithm processing. Three I / O pins are connected to the one-way valve, unloading device, and vibration ring, respectively, and are used by the core processor to control the end of the acquisition. The core processor periodically sends low and high levels to the I / O pins to control the one-way valve, unloading device, and vibration ring, respectively. The system clock is the driving source for the CPU's various operating timing sequences and is connected to the peripheral circuits. The RAM is connected to an external LCD module, displaying the acoustic wave frequency division energy distribution, slurry flow velocity data, pipeline deformation data, and the calculated distance between the pipeline blockage location and the starting armored optical cable acquired by the core processor on the LCD module. The power supply provides power to the core processor. The SRAM interface module is connected to the data bus and its input is connected to the variable step size minimum mean square algorithm filter processing module. It is then connected to the variable step size minimum mean square algorithm filter processing module and the empirical mode decomposition combined with energy detection processing module. The empirical mode decomposition combined with energy detection processing module is then connected to the frequency division energy calculation module / pipeline deformation calculation module. Data from the infrasound sensor A / D acquisition control module is sequentially transmitted to these modules, and the results are calculated using the frequency division energy calculation module / pipeline deformation calculation module. The data is then used by the filling pipe positioning calculation module to determine the distance between the plugging location and the starting armored optical cable. The SRAM interface module is also connected to the data bus and its input is connected to the slurry velocity calculation module. Data from the pressure sensor A / D acquisition control module is transmitted to the slurry velocity calculation module, and the data is then used by the filling pipe positioning calculation module to determine the distance between the plugging location and the starting armored optical cable.

[0034] like Figures 9-10 As shown, a method for using a monitoring and control system for filling and blocking pipes includes the following steps: S1, Fiber optic cable laying steps: Lay single-mode armored optical cable directly above the axis of the filling pipe, and fix it with pre-tension clamps every 10 m to ensure that the optical cable is tightly attached to the pipe wall.

[0035] S2, System Operation Flow: After startup, the system updates the acoustic frequency distribution energy distribution, pipe deformation diagram, and slurry flow velocity diagram of the filling pipe every 5 seconds, and calculates and identifies the slurry blockage location in each area; S3, Pipe Blockage Detection and Active Prevention: The ground-based integrated control console calculates the full-range acoustic frequency division energy, pipeline deformation, and slurry flow velocity based on real-time data. When any two of these three exceed the limit, a first-level pressure relief is triggered, and the unloading system is started. If the exceeding item does not return to a safe value within 10 seconds, a second-level pressure relief is initiated, and a manual intervention mode is triggered. After the pipe blockage is cleared, the system automatically records the fault parameters, optimizes the threshold library, and generates an operation and maintenance report.

[0036] S4, Maintenance Mechanism: Daily optical cable link attenuation test is performed, and a self-test program is triggered when the loss fluctuation is >0.2 dB; every quarter, acoustic energy calibration is performed by applying a standard vibration signal through an exciter to determine the mapping coefficient.

[0037] In this embodiment, during steps S2 and S3, when calculating and identifying the blockage location of the filling grout in each region, calculating the full-domain acoustic frequency division energy of the pipeline, pipeline deformation, and grout flow velocity, data processing is performed according to the following steps: Step 1: Preprocess the collected acoustic data using the variable step size least mean square algorithm; specific implementation process: (1) Initialization: Set the initial weight vector w(0)=0; The initial step size factor μ0 is typically set to 0.01 - 0.1. The error threshold ξ is used for step size adjustment; Iteration count k=1; (2) For the k-th iteration: Calculate the error between the desired signal and the actual output: e(k) = d(k) - x(k)Tw(k-1); Where d(k) is the reference signal; x(k) is the input acoustic data vector at time k; Dynamically adjust the step size factor: update the step size μ(k) according to the error magnitude. A commonly used adjustment formula is: Update the weight vector: w(k) = w(k-1) + μ(k)e(k)x(k); Let k = k + 1, and repeat step 2 until the iteration ends or the error converges to the preset range; Step 2: Based on the data processed in Step 1, empirical mode decomposition combined with energy detection is used to divide the acoustic wave frequency energy. Empirical Mode Decomposition (EMD) does not require preset basis functions and can adaptively decompose non-stationary acoustic signals into a series of Intrinsic Mode Functions (IMFs). Each IMF corresponds to a signal component at a different frequency scale. Combined with energy detection, it can accurately extract the frequency domain features of choking echoes, compensating for the insufficient adaptability of wavelet transform to non-stationary signals. The implementation process is as follows: (1) Signal preprocessing: The noise-reduced acoustic signal output in step 1 is subjected to extreme point detection to remove abnormal pulse interference; (2) Empirical Mode Decomposition: Identify the local maxima and minima of the signal, fit the upper and lower envelopes using cubic spline interpolation, and calculate the mean value m1(t) of the envelopes; Extract the first intrinsic mode function IMF1(t) = s(t) - m1(t). If IMF1(t) satisfies the conditions of intrinsic mode function (the number of extreme points and zero crossings are equal or differ by 1, and the average value of the upper and lower envelopes is 0), then separate the component; otherwise, repeat the above process with IMF1(t) as a new signal until all IMF components are obtained. The remaining signal is the residual component r(t), which represents the trend term of the signal; (3) Frequency division energy calculation: Perform Hilbert transform on each IMF component to obtain the instantaneous frequency and instantaneous amplitude, and calculate the energy of each IMF. ; (4) Blocking echo identification: Analyze the energy distribution of each IMF. Blocking echoes usually show energy abrupt changes in a specific IMF component. Combine the residual components to locate the time position of the echo. Analysis and calculation process of acoustic wave frequency division energy data and pipeline deformation data: Calculating the frequency-divided energy of sound waves requires combining signal processing theory with acoustic characteristics. The sound waves are decomposed into different frequency components through frequency domain analysis, and the energy of each frequency band is calculated. The following are the detailed theoretical basis and calculation steps: Time-domain representation of sound waves Sound waves can be represented as time-domain signals p(t), where p is the sound pressure and t is time; the total energy E of the sound wave is defined in the time domain as... Where Z is the characteristic impedance of the dielectric. Frequency domain transformation: Fourier transform; The time-domain signal is converted into the frequency-domain spectrum P(f) by Fourier transform, satisfying: ; According to Parseval's theorem, the energy in the time domain is equal to the energy in the frequency domain: ; Where is the power spectral density, representing the energy per unit frequency; Frequency division energy calculation steps (1) Define the frequency band range: For example, divide it into M frequency bands [flow,i, fhigh,i] (i=1,2,…,M); (2) Integrate the power spectral density over each frequency band: ; in, =fs / N; Frequency division energy characterizes the blocked area. Based on the calculated frequency division energy of each frequency band, the higher the energy, the higher the probability of pipe blockage; combined with the starting position of the initial armored optical cable, the pipe blockage location can be located in the frequency domain. Calculate the deformation of the filling pipe (1) Sound pressure (p) is the fluctuation of medium pressure during sound wave propagation, and its relationship with stress (σ) is: p ~ σ; (2) According to Hooke's Law, the relationship between stress and strain is: σ = K⋅ε. For sound waves, the relationship between bulk modulus and medium density (ρ) and wave velocity (c) is: K = ρc 2 ; (3) ε=p / K, that is, if the sound pressure amplitude P is known, then the strain amplitude is: ε=P / ρc 2 ; (4) ε = ΔL / L, where ΔL is the pipe deformation and L is the pipe circumference; Pipe deformation characterizes the blocked area The deformation of the filling pipe for each frequency band is calculated. The greater the deformation, the higher the probability of pipe blockage. Combined with the starting position of the initial armored optical cable, the location of the blockage is located in the frequency domain. Analysis and calculation process of slurry flow velocity data: In a filled pipe (full pipe flow), the relationship between fluid pressure and velocity can be derived from the basic principles of fluid mechanics and the law of conservation of energy, but it needs to be calculated in conjunction with Bernoulli's equation. For incompressible steady flow, the energy conservation equation along the streamline is: ; Where p is the fluid pressure (Pa) and ρ is the fluid density (kg / m³). 3 g is the acceleration due to gravity (m / s²). 2 v is the average fluid velocity (m / s), z is the position height (m), and C is a constant. Slurry flow velocity characterizes the blocked pipe area Based on the test data from the pressure sensor and the relationship between pressure and flow rate in Bernoulli's equation, the higher the pressure and the lower the flow rate, the higher the degree of pipe blockage. Combined with the initial injection position of the filling slurry, the location of the blockage can be determined.

[0038] To better illustrate the technical content involved in this application, the working principle of the technical content is explained in detail below: Working principle: During the grout delivery process in the filling pipeline, various filling grouts were designed for data acquisition (three types in this embodiment). This process ensures the completeness of experimental data under pump pressure and filling grout conditions, facilitating a comprehensive analysis of the acoustic wave generation and propagation characteristics in the blocked area of ​​the filling pipeline, and establishing an accurate filling and blockage model. The specific experimental steps are as follows: 1. Start the monitoring system Open the DAS system and set the acquisition parameters (such as sampling frequency, sampling interval, data storage length, etc.). In this embodiment, the acquisition mode is differential data, the sampling frequency is 4kHz, the sampling interval is 0.25m, and the single data storage duration is 30 seconds.

[0039] Simultaneously, the filling system is started, and the unit of flow rate, sampling frequency, etc., are set. In this embodiment, the unit of flow rate is m³. 3 / h, with a sampling frequency of 1Hz.

[0040] Simultaneously activate the ground integrated control console, the ground filling system, and the pressure sensor system.

[0041] The synchronous filling system is synchronized with the DAS system and pressure sensor system to enable effective data comparison and analysis.

[0042] 2. Inject the first type of filling slurry. The first type of red mud-based backfill slurry was selected for the experiment. After being stirred using a mixing system, the slurry was evenly loaded into the silo via a heavy hopper, ensuring tight and uniform packing to avoid experimental errors caused by uneven rock sample filling. The slurry was then flow-tested within the backfilling pipeline using an industrial pump. Data acquisition began under stable flow conditions, and a pressure stabilization system was used to ensure high-quality acoustic signal acquisition under stable flow conditions.

[0043] 3. Data Collection From an initial stable flow rate, such as 1m 3 / h, start collecting data until the minimum flow rate designed for the flow experiment is reached, such as 0.1m³. 3 After / h, data collection will stop.

[0044] 4. Replace the filling slurry and repeat steps 2-3: Replace with the second type of filling slurry, which in this embodiment is coal-based solid waste filling slurry, and repeat steps 2-3.

[0045] Replace with a third type of filling slurry, which in this embodiment is a fly ash-based filling slurry, and repeat steps 2-3.

[0046] 6. Shut down the device and data processing. After the experiment, shut down the filling industrial pump control system, filling system, DAS system, and other systems in the correct order to ensure safe equipment shutdown. Then, flush the pipeline with the filling slurry and thoroughly clean the equipment to ensure its normal operation in subsequent experiments.

[0047] Finally, all collected acoustic data were analyzed in detail. Based on conditions such as pump pressure and filling slurry, sensitive acoustic features related to the blocked pipe area were extracted. A multi-parameter correlation analysis of the full-domain acoustic frequency energy distribution, slurry velocity map, and pipe deformation map was established to improve the accuracy and reliability of the degree of blockage in mine filling.

[0048] Compared with existing technologies, this invention, on the one hand, constructs a distributed fiber optic acoustic sensing network by laying single-mode armored optical cables along the upper part of the entire filling pipeline. Through the elastic-optical effect, it demodulates the acoustic data of the entire pipeline in real time, establishing a multi-parameter correlation analysis of the full-domain acoustic frequency-division energy distribution, pipeline deformation, and slurry flow velocity to accurately locate the blockage. On the other hand, based on the multi-parameter correlation analysis of the filling pipeline and combined with the spatiotemporal evolution of acoustic signals, it determines the blockage area and actively controls the filling blockage through pressure relief valves and vibration rings. This solves the problem of response lag in traditional manual inspections or single-parameter triggering, improving the timeliness of on-site emergency response.

[0049] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0050] In the description of this specification, the terms "connection", "installation", "fixing", "setting", etc. are interpreted broadly. For example, "connection" can be a fixed connection or an indirect connection through an intermediate component without affecting the relationship between components and the technical effect. It can also be an integral connection or a partial connection. In such cases, those skilled in the art can understand the specific meaning of the above terms in this invention or invention according to the specific circumstances.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A monitoring and control system for pipe filling blockage, characterized in that, The monitoring and prevention and control system for filling pipe plugging includes a ground integrated console, a distributed fiber optic acoustic monitoring system, a pressure detection mechanism, and a material discharging mechanism. The ground integrated console is electrically connected to the distributed fiber optic acoustic monitoring system, the pressure detection mechanism, and the material discharging mechanism respectively through a communication system and establishes a data connection. There is at least one of the distributed fiber optic acoustic monitoring system and the pressure detection mechanism, which is connected to the wall of the filling pipe and distributed along the axis direction of the filling pipe. There are several material discharging mechanisms, which are connected to the filling pipe, distributed along the axis direction of the filling pipe, and the distance between adjacent two material discharging mechanisms is 9 - 15 meters.

2. The monitoring and control system for filling and plugging pipes according to claim 1, characterized in that, The material discharging mechanism includes a discharging mechanism, a vibration ring, and a detection sensor group. The discharging mechanism is located inside the filling pipe and is connected to the inner side surface at the bottom position inside the filling pipe. At the same time, the discharging mechanism is located on the front side of the vibration ring along the axis direction of the filling pipe, and the detection sensor group is connected to the wall of the filling pipe and is located between the discharging mechanism and the vibration ring. The discharging mechanism, the vibration ring, and the detection sensor group are all connected to the ground integrated console.

3. The monitoring and control system for filling and plugging pipes according to claim 2, characterized in that, The discharging mechanism includes a discharge filter plate, an adjusting seat, and a movable turntable. The adjusting seat is of an annular structure, and a through hole is provided at the corresponding filling pipe wall. At the same time, the through hole is coaxially distributed with the adjusting seat, and its axis intersects and is perpendicular to the axis of the filling pipe. The discharge filter plate is embedded in the adjusting seat and is slidably connected to the adjusting seat through the movable turntable to block the through hole. At the same time, the movable turntable is electrically connected to the ground integrated console.

4. The monitoring and control system for filling and blocking pipes according to claim 2, characterized in that, The vibration ring includes an exciter, an elastic cushion block, a positioning base, a bearing spring, and an ultrasonic oscillation mechanism. There are two positioning bases in total, both of which are arc-shaped groove structures with a cross-section in the shape of "凵", and the two positioning bases are connected by bolts and form a closed annular structure coaxially distributed with the filling pipe. There are at least two elastic cushion blocks, which are evenly distributed around the axis of the filling pipe. One end of each elastic cushion block abuts against the surface of the filling pipe, and the other end is connected to a bearing spring and is coaxially distributed with the bearing spring. The axis of the elastic cushion block intersects and is perpendicular to the axis of the filling pipe. At the same time, the bearing spring is also connected to the bottom of the groove on the inner side surface of the positioning base. In addition, an ultrasonic oscillation mechanism coaxially distributed with each elastic cushion block is provided inside each elastic cushion block. There is at least one exciter, which is connected to the outer side surface of the positioning base, and the vibration direction of the exciter forms an angle of 0° - 90° with the vibration direction of the ultrasonic oscillation mechanism. The exciter and the ultrasonic oscillation mechanism are both electrically connected to the ground integrated console.

5. The monitoring and control system for filling and plugging pipes according to claim 1, characterized in that, The distributed fiber optic acoustic monitoring system includes a single-mode armored optical cable, a distributed fiber optic acoustic sensing mechanism, and a measurement and control and signal processing mechanism. The single-mode armored optical cable is laid along the upper part of the filling pipe and is distributed parallel to the pipe's axis. Several distributed fiber optic acoustic sensing mechanisms are distributed along the filling pipe's axis and connected to the single-mode armored optical cable, and also connected to the measurement and control and signal processing mechanism. The measurement and control and signal processing mechanism is connected to a ground-based integrated control console. Each distributed fiber optic acoustic sensing mechanism includes a light pulse generation module, a light intensity detection module, and a fiber optic circulator. The light pulse generation module is connected to the single-mode armored optical cable on one side and to the fiber optic circulator through the light intensity detection module on the other. The fiber optic circulator and the light intensity detection module are connected to the measurement and control and signal processing mechanism, and the measurement and control and signal processing mechanism is connected to the ground-based integrated control console via a communication system.

6. The monitoring and control system for filling and plugging pipes according to claim 5, characterized in that, The optical pulse generation module includes a narrow linewidth laser, an optical fiber coupler, an acousto-optic modulator, and an erbium-doped fiber amplifier. The narrow linewidth laser is connected to the optical fiber coupler, and the first output end of the optical fiber coupler is connected to the first input end of the optical quantity detection module, while the second output end is connected to the first input end of the acousto-optic modulator. The acousto-optic modulator is also connected to the erbium-doped fiber amplifier. The erbium-doped fiber amplifier is connected to an optical fiber circulator.

7. The monitoring and control system for filling and plugging pipes according to claim 5, characterized in that, The light intensity detection module includes a polarization diversity receiver and a photodetector. The first output of the fiber coupler is connected to the input of the polarization diversity receiver, and the second output is connected to the input of the acousto-optic modulator. The output of the acousto-optic modulator is connected to the input of the erbium-doped fiber amplifier, and the output of the erbium-doped fiber amplifier is connected to a circulator.

8. The monitoring and control system for filling and plugging pipes according to claim 1, characterized in that, The pressure detection mechanism includes a power module, a data acquisition card, a filling parameter master station, a pressure sensor, and an electronic concentration meter. Each of the pressure sensor and the electronic concentration meter has at least one and is connected to the inner side of the outer wall of the filling pipeline. The pressure sensor and the electronic concentration meter are electrically connected to the power module and the data acquisition card, and the power module and the data acquisition card are electrically connected to the filling parameter master station. The filling parameter master station is also connected to the ground integrated control console.

9. The operation method of the monitoring and control system for filling and plugging pipes according to claim 1, characterized in that, The operation method of the monitoring and control system for filling and plugging includes the following steps: S1, Fiber optic cable laying steps: Lay single-mode armored optical cable directly above the axis of the filling pipe, and fix it with pre-tension clamps every 10 m to ensure that the optical cable is tightly attached to the pipe wall; S2, System Operation Flow: After startup, the system updates the acoustic frequency distribution energy distribution, pipe deformation diagram, and slurry flow velocity diagram of the filling pipe every 5 seconds, and calculates and identifies the slurry blockage location in each area; S3, Pipe Blockage Detection and Active Prevention: The ground-based integrated control console calculates the full-range acoustic frequency division energy, pipeline deformation, and slurry flow velocity based on real-time data. When any two of these three exceed the limit, a first-level pressure relief is triggered, and the unloading system is started. If the exceeding item does not return to a safe value within 10 seconds, a second-level pressure relief is initiated, and a manual intervention mode is triggered. After the pipe blockage is cleared, the system automatically records the fault parameters, optimizes the threshold library, and generates an operation and maintenance report. S4, Maintenance Mechanism: Daily optical cable link attenuation test is performed, and a self-test program is triggered when the loss fluctuation is >0.2 dB; Acoustic energy calibration is performed quarterly by applying a standard vibration signal through an exciter to determine the mapping coefficient.

10. The operation method of the monitoring and control system for filling and plugging pipes according to claim 9, characterized in that, In steps S2 and S3, when calculating and identifying the blockage location of the filling grout in each region, calculating the overall acoustic frequency division energy of the pipeline, pipeline deformation, and grout flow velocity, data processing is performed according to the following steps: Step 1: Preprocess the collected acoustic data using the variable step size least mean square algorithm; specific implementation process: (1) Initialization: Set the initial weight vector w(0)=0; The initial step size factor μ0 is typically set to 0.01 - 0.

1. The error threshold ξ is used for step size adjustment; Iteration count k=1; (2) For the k-th iteration: Calculate the error between the desired signal and the actual output: e(k) = d(k) - x(k)Tw(k-1); Where d(k) is the reference signal; x(k) is the input acoustic data vector at time k; Dynamically adjust the step size factor: update the step size μ(k) according to the error magnitude. A commonly used adjustment formula is: Update the weight vector: w(k) = w(k-1) + μ(k)e(k)x(k); Let k = k + 1, and repeat step 2 until the iteration ends or the error converges to the preset range; Step 2: Based on the data processed in Step 1, empirical mode decomposition combined with energy detection is used to divide the acoustic wave frequency energy. Empirical Mode Decomposition (EMD) does not require preset basis functions and can adaptively decompose non-stationary acoustic signals into a series of Intrinsic Mode Functions (IMFs). Each IMF corresponds to a signal component at a different frequency scale. Combined with energy detection, it can accurately extract the frequency domain features of choking echoes, compensating for the insufficient adaptability of wavelet transform to non-stationary signals. The implementation process is as follows: (1) Signal preprocessing: The noise-reduced acoustic signal output in step 1 is subjected to extreme point detection to remove abnormal pulse interference; (2) Empirical Mode Decomposition: Identify the local maxima and minima of the signal, fit the upper and lower envelopes using cubic spline interpolation, and calculate the mean value m1(t) of the envelopes; Extract the first intrinsic mode function IMF1(t) = s(t) - m1(t). If IMF1(t) satisfies the conditions of intrinsic mode function (the number of extreme points and zero crossings are equal or differ by 1, and the average value of the upper and lower envelopes is 0), then separate the component; otherwise, repeat the above process with IMF1(t) as a new signal until all IMF components are obtained. The remaining signal is the residual component r(t), which represents the trend term of the signal; (3) Frequency division energy calculation: Perform Hilbert transform on each IMF component to obtain the instantaneous frequency and instantaneous amplitude, and calculate the energy of each IMF. ; (4) Blocking echo identification: Analyze the energy distribution of each IMF. Blocking echoes usually show energy abrupt changes in a specific IMF component. Combine the residual components to locate the time position of the echo. Analysis and calculation process of acoustic wave frequency division energy data and pipeline deformation data: Calculating the frequency-divided energy of sound waves requires combining signal processing theory with acoustic characteristics. The sound waves are decomposed into different frequency components through frequency domain analysis, and the energy of each frequency band is calculated. The following are the detailed theoretical basis and calculation steps: Time-domain representation of sound waves Sound waves can be represented as time-domain signals p(t), where p is the sound pressure and t is time; the total energy E of the sound wave is defined in the time domain as... Where Z is the characteristic impedance of the dielectric. Frequency domain transformation: Fourier transform; The time-domain signal is converted into the frequency-domain spectrum P(f) by Fourier transform, satisfying: ; According to Parseval's theorem, the energy in the time domain is equal to the energy in the frequency domain: ; Where is the power spectral density, representing the energy per unit frequency; Frequency division energy calculation steps (1) Define the frequency band range: For example, divide it into M frequency bands [flow,i, fhigh,i] (i=1,2,…,M); (2) Integrate the power spectral density over each frequency band: ; in, =fs / N; Frequency division energy characterizes the blocked area. Based on the calculated frequency division energy of each frequency band, the higher the energy, the higher the probability of pipe blockage; combined with the starting position of the initial armored optical cable, the pipe blockage location can be located in the frequency domain. Calculate the deformation of the filling pipe (1) Sound pressure (p) is the fluctuation of medium pressure during sound wave propagation, and its relationship with stress (σ) is: p ~ σ; (2) According to Hooke's Law, the relationship between stress and strain is: σ = K⋅ε. For sound waves, the relationship between bulk modulus and medium density (ρ) and wave velocity (c) is: K = ρc 2 ; (3) ε=p / K, that is, if the sound pressure amplitude P is known, then the strain amplitude is: ε=P / ρc 2 ; (4) ε = ΔL / L, where ΔL is the pipe deformation and L is the pipe circumference; Pipe deformation characterizes the blocked area The deformation of the filling pipe for each frequency band is calculated. The greater the deformation, the higher the probability of pipe blockage. Combined with the starting position of the initial armored optical cable, the location of the blockage is located in the frequency domain. Analysis and calculation process of slurry flow velocity data: In a filled pipe (full pipe flow), the relationship between fluid pressure and velocity can be derived from the basic principles of fluid mechanics and the law of conservation of energy, but it needs to be calculated in conjunction with Bernoulli's equation. For incompressible steady flow, the energy conservation equation along the streamline is: ; Where p is the fluid pressure (Pa) and ρ is the fluid density (kg / m³). 3 g is the acceleration due to gravity (m / s²). 2 v is the average fluid velocity (m / s), z is the position height (m), and C is a constant. Slurry flow velocity characterizes the blocked pipe area Based on the test data from the pressure sensor and the relationship between pressure and flow rate in Bernoulli's equation, the higher the pressure and the lower the flow rate, the higher the degree of pipe blockage. Combined with the initial injection position of the filling slurry, the location of the blockage can be determined.

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