An integrated equipment for downhole multi-disaster sensing and intelligent emergency control

Abstract

The application discloses an integrated equipment for downhole multi-disaster sensing and intelligent emergency control, and relates to the technical field of mine safety. The equipment comprises fluid-induced sound and jet flow generating devices arranged in a ring array, electrostatic induction sensing devices, spectral tomography detection devices and a central control and demodulation unit. The fluid-induced sound and jet flow generating devices are configured to construct a sound pressure standing wave field by using bistable fluid oscillation in a monitoring mode, and to form an inverted conical aerodynamic closed vortex ring by adjusting the jet flow deflection angle by using the Coanda effect in a blocking mode. The electrostatic induction sensing devices collect sound wave modulated charge density fluctuation signals, and the central control and demodulation unit determines disasters by demodulating the sound wave carrier characteristics and combining the spectral tomography inversion gas concentration distribution to generate vector control instructions. The application eliminates electromagnetic interference through the coupling mechanism of sound and electric physical fields, and realizes advanced sensing and adaptive spatial blocking of dynamic disasters by using fluid vector control.

Description

Technical Field

[0001] This invention belongs to the field of mine safety, specifically relating to an integrated equipment for underground multi-hazard sensing and intelligent emergency control. Background Technology

[0002] In underground coal mining, real-time monitoring of dynamic hazards such as gas outbursts and coal dust explosions is a crucial aspect of ensuring safe production. Existing hazard monitoring methods primarily rely on electrochemical or catalytic combustion sensors to detect gas concentrations. Some technologies also employ non-contact electrostatic induction principles to monitor the flow state of gas-solid two-phase fluids, utilizing the electrostatic effect generated by the friction between high-speed coal dust and gas flows and the roadway. Current systems typically trigger alarms or implement interlocking controls such as power-off spraying when the detected electrostatic signal amplitude or gas concentration exceeds a preset static threshold.

[0003] However, the underground environment presents complex electromagnetic conditions. The startup and operation of high-power electromechanical equipment, frequency converters, and power cables generate strong electromagnetic radiation. These electromagnetic interference signals can easily couple into the induction circuit of electrostatic monitoring equipment, forming signal abrupt changes in waveform characteristics similar to those of current-carrying fluids. Because existing electrostatic induction sensing technologies generally lack mechanisms for identifying the physical properties of the signal source, relying solely on amplitude thresholds or trends for judgment, it is difficult to effectively distinguish between electrostatic signals generated by fluid flow from physical disasters and false signals generated by environmental electromagnetic interference. This leads to false alarms in monitoring systems under complex conditions, affecting normal production order and reducing the reliability of safety monitoring systems. Summary of the Invention

[0004] This invention aims to address the technical problems of existing downhole disaster monitoring technologies, such as sensor response lag, susceptibility to false alarms due to electromagnetic interference, and low efficiency of passive isolation. This invention proposes an active sensing and vector control technology based on a physical field coupling mechanism, achieving advanced sensing and dynamic pneumatic isolation of downhole dynamic disasters.

[0005] The first aspect of this invention provides an integrated equipment for downhole multi-hazard sensing and intelligent emergency control.

[0006] The integrated equipment for multi-hazard perception and intelligent emergency control in underground mines includes: fluid acoustic and jet generating devices arranged in a ring array, electrostatic induction sensing devices located downstream of or integrated with the fluid acoustic and jet generating devices, spectral tomography detection devices covering the roadway cross section, and a central control and demodulation unit that connects the above devices to the signals.

[0007] The fluid acoustic and jet generator is fixedly installed on the circumferential inner wall of a mine roadway. The generator has an internal, interconnected flow channel structure, including a main gas source inlet, a bistable interaction cavity, a feedback channel, and an expansion output nozzle. The generator is equipped with a monitoring mode and a blocking mode. In monitoring mode, the generator utilizes the self-excited oscillation of the fluid within the bistable interaction cavity to emit ultrasonic waves of a preset frequency into the monitoring area of ​​the roadway, thereby constructing a background sound pressure standing wave field within the monitoring area. In blocking mode, the generator injects control fluid into the bistable interaction cavity to disrupt the self-excited oscillation and utilizes the Coanda effect to change the wall attachment state of the main jet, ejecting high-pressure gas and forming an aerodynamic sealing barrier on the roadway cross-section.

[0008] The electrostatic induction sensing device is configured to non-contactly acquire the charge density fluctuation signal of the fluid medium within the roadway monitoring area. The device utilizes an array of inductive electrodes to capture the static charge generated in the fluid medium due to triboelectric effect and outputs an analog electrical signal containing acoustic wave carrier characteristics.

[0009] The spectroscopic tomography device includes multiple sets of laser emitters and receivers arranged on the tunnel perimeter, forming a multi-path scanning grid within the tunnel cross-section. The spectroscopic tomography device is configured to acquire gas absorption spectral data from the tunnel cross-section for inversion calculations of gas composition and two-dimensional concentration distribution within the tunnel cross-section.

[0010] The central control and demodulation unit is configured to simultaneously process analog electrical signals and gas absorption spectral data. It demodulates the charge density fluctuation signal to extract acoustic modulation characteristics, determines the presence of acoustically modulated fluid based on these characteristics, and calculates the gas concentration distribution using the gas absorption spectral data. Based on the determination, the central control and demodulation unit generates mode switching commands and control parameters for the fluid acoustic and jet generation devices.

[0011] In some embodiments, the fluid acoustic and jet generating device utilizes the momentum flux interaction between the control fluid injected into the control jet channel and the main jet to adjust the wall attachment length of the main jet on the Coanda surface of the inner wall of the expanding output nozzle, thereby continuously adjusting the deflection angle of the jet without changing the mechanical structure. Multiple fluid acoustic and jet generating devices arranged in a ring array work together to cause the ejected high-energy jets to converge at a predetermined position on the central axis of the tunnel, forming an inverted conical aerodynamic closed vortex ring. This inverted conical aerodynamic closed vortex ring generates axial stagnation pressure opposite to the direction of the intrusive fluid intrusion.

[0012] A second aspect of the present invention provides a method for downhole multi-hazard sensing and intelligent emergency control based on the above-mentioned equipment.

[0013] The downhole multi-hazard perception and intelligent emergency control method includes: system initialization and acoustic field construction, acoustic-electric modulation signal acquisition, signal demodulation and physical field feature extraction, synchronous tomographic imaging verification, multi-dimensional criterion fusion and decision-making, vector jet blocking execution, and dynamic adaptive adjustment steps.

[0014] In the signal demodulation and physical field feature extraction steps, the central control and demodulation unit performs frequency domain analysis on the induced current signal output by the electrostatic induction sensing device to extract the power spectral density of the induced current signal. The central control and demodulation unit then searches for a spectral peak centered on the emission angular frequency within the power spectral density to extract the maximum peak energy value. The central control and demodulation unit compares the maximum peak energy value with a preset acoustic modulation energy threshold. If the maximum peak energy value exceeds the acoustic modulation energy threshold, it determines that there is a solid fluid modulated by acoustic waves within the tunnel monitoring area, thereby eliminating electromagnetic interference signals that do not possess acoustic modulation characteristics.

[0015] Meanwhile, the central control and demodulation unit calculates the macroscopic velocity of the fluid medium using the Doppler effect principle. Based on the frequency offset between the extracted actual peak frequency and the preset transmission angular frequency, combined with the sound velocity in the mine environment and the preset angle between the fluid flow direction and the sound wave propagation direction, the central control and demodulation unit calculates the macroscopic velocity of the fluid medium.

[0016] In this step, the central control and demodulation unit discretizes the tunnel monitoring cross-section into a grid pixel matrix. Based on the Beer-Lambert law, a system of linear equations is established between the integrated concentration of each optical path and the concentration of each grid pixel. The central control and demodulation unit solves the linear equations using an algebraic reconstruction algorithm or a joint iterative reconstruction algorithm to generate a two-dimensional gas concentration distribution matrix of the tunnel cross-section, and extracts the maximum local concentration value from the two-dimensional gas concentration distribution matrix.

[0017] In the multidimensional criterion fusion and decision-making process, when the calculated macroscopic flow velocity is greater than the flow velocity alarm threshold and the maximum local concentration value is greater than the concentration alarm threshold, the central control and demodulation unit generates a blocking mode switching command.

[0018] In the vector jet blocking execution step, the central control and demodulation unit calculates the target jet deflection angle that can balance the momentum of the disaster fluid based on the macroscopic flow velocity of the fluid medium, and consults the jet deflection angle-control pressure mapping table to determine the corresponding control fluid drive voltage value. The central control and demodulation unit adjusts the control fluid pressure injected into the control jet channel to change the momentum flux ratio between the control fluid and the main jet, thereby controlling the deflection angle of the main jet and implementing adaptive spatial blocking.

[0019] Compared with the prior art, the beneficial effect of the present invention is that it constructs a sound pressure standing wave field by using fluid acoustic and jet generation devices, and uses sound radiation force to periodically modulate charged particles in multiphase fluids, so that the electrostatic induction signal is superimposed with the sound wave carrier characteristics. The central control and demodulation unit can then distinguish between physical fluid and electromagnetic interference, thereby eliminating false signals that are not modulated by sound waves at the physical principle level and solving the problem of false alarms caused by electrostatic monitoring being easily interfered with by electromechanical equipment.

[0020] By integrating the acoustic wave emission source and the jet actuator into the same device, the communication delay between independent sensing and execution devices is eliminated. The electric field propagation speed and Doppler frequency shift effect are used to replace traditional gas diffusion detection, breaking through the physical bottleneck of the response lag of chemical sensors and realizing millisecond-level advanced sensing and in-situ rapid isolation of dynamic disasters.

[0021] By controlling the injection of fluid into the jet channel and utilizing the Coanda effect to change the attachment state of the main jet to the wall, the jet deflection angle can be continuously adjusted without mechanical moving parts, so that the jets ejected from the annular array converge to form an inverted conical aerodynamic closed vortex ring. The axial stagnation pressure generated by this aerodynamic closed vortex ring can be adaptively adjusted according to the dynamic pressure of the disaster fluid impact, thereby constructing a dynamically adaptive aerodynamic barrier. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the system architecture interaction of the present invention.

[0023] Figure 2 This is a flowchart illustrating the method logic control of the present invention. Detailed Implementation

[0024] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0025] like Figure 1 and Figure 2 As shown, an integrated equipment for multi-hazard sensing and intelligent emergency control in underground mines includes a fluid acoustic and jet generating device arranged in a ring array, an electrostatic induction sensing device located downstream, a spectral tomography detection device covering the cross-section of the roadway, and a central control and demodulation unit that connects the above devices to the signal.

[0026] The fluid acoustic and jet generator is fixedly installed on the circumferential inner wall of the mine roadway. Inside the generator is a bistable fluid oscillation chamber and a control jet channel. The generator is configured to switch between monitoring and isolation modes. In monitoring mode, the generator uses low-pressure fluid self-excited oscillation to emit ultrasonic waves of a preset frequency into the monitoring area of ​​the roadway, constructing a sound pressure standing wave field. In isolation mode, the generator increases the fluid pressure and adjusts the pressure difference in the control jet channel to spray high-pressure gas and form a pneumatically sealed barrier on the roadway cross-section.

[0027] The electrostatic induction sensing device is located downstream of or integrated with the fluid acoustic and jet generation device. The electrostatic induction sensing device is configured to non-contactly acquire the charge density fluctuation signal of the fluid medium within the monitoring area and convert the charge density fluctuation signal into an analog electrical signal output.

[0028] The spectroscopic tomography detection device includes multiple sets of laser emitters and receivers, which are arranged crosswise on the tunnel perimeter wall to form a multi-path scanning grid within the tunnel cross-section. The spectroscopic tomography detection device is configured to acquire gas absorption spectral data from the tunnel cross-section for calculating gas composition and concentration distribution.

[0029] The central control and demodulation unit is connected to the fluid acoustic and jet generator, the electrostatic sensing device, and the spectral tomography detection device via wired transmission lines or industrial fieldbuses. The central control and demodulation unit is configured to synchronously process analog electrical signals and spectral data, and generate mode switching commands for the fluid acoustic and jet generator based on the processing results.

[0030] During the operation of the integrated downhole disaster prevention system, the fluid acoustic and jet generator is initially in monitoring mode. The fluid acoustic and jet generator utilizes the wall-attached oscillation of fluid within a bistable fluid oscillation chamber to generate a frequency of... The ultrasonic waves. Multiple fluid acoustic and jet generating devices work in phase to establish a sound pressure standing wave field within the tunnel monitoring area, which serves as the background detection field for the system.

[0031] When a high-speed multiphase fluid enters the monitoring area, the solid or liquid particles in the fluid generate static charges due to collisions with the tunnel walls and between particles. Simultaneously, the high-speed multiphase fluid is subjected to the acoustic radiation force of the acoustic pressure standing wave field, causing the spatial distribution density of charged particles to change in relation to the sound wave frequency. The corresponding periodic density modulation.

[0032] The electrostatic induction sensing device captures changes in charge density modulated by sound waves and outputs an induced current signal containing the characteristics of the sound wave carrier.

[0033] The central control and demodulation unit receives the induced current signal and performs demodulation operations. The central control and demodulation unit extracts the frequency from the induced current signal... The amplitude and frequency offset of the component. If the induced current signal contains a frequency of... The modulation component is determined by the central control and demodulation unit to originate from a physical fluid, thus distinguishing it from electromagnetic interference signals that do not possess acoustic modulation characteristics.

[0034] Meanwhile, the central control and demodulation unit calculates the fluid velocity based on the frequency offset and determines the disaster type by combining the gas composition data fed back by the spectral tomography detection device.

[0035] When the judgment result meets the preset disaster trigger threshold, the central control and demodulation unit sends a blocking mode switching command to the fluid acoustic and jet generator. The fluid acoustic and jet generator responds to the blocking mode switching command and switches to blocking mode.

[0036] In the isolation mode, the fluid acoustic and jet generating devices utilize the Coanda effect to deflect the main jet direction toward the central axis of the roadway by changing the momentum ratio between the control jet channel and the main jet channel. The jets ejected from multiple fluid acoustic and jet generating devices distributed in a ring array converge at the center of the roadway, forming an inverted conical aerodynamic vortex ring covering the entire cross-section of the roadway. This aerodynamic pressure is used to balance the impact dynamic pressure of the hazardous fluid, thus spatially isolating the hazardous fluid.

[0037] Fluid acoustic and jet generation devices, along with electrostatic induction sensing devices, constitute the hardware foundation for physical field coupling.

[0038] The fluid acoustic and jet generating device includes a fluid oscillator body. The fluid oscillator body has a connected flow channel structure inside, which, along the fluid flow direction, sequentially includes: a main gas source inlet, a constricting nozzle section, a bistable interaction chamber, and an expanding output nozzle at the end. The main gas source inlet is connected to an external high-pressure gas supply pipeline.

[0039] The main air source inlet of the fluid acoustic and jet generation device is equipped with a fast-response solenoid valve or flow regulator. The central control and demodulation unit fine-tunes the oscillation frequency by adjusting the air source input pressure of each device, or achieves phase synchronization between multiple devices through the timing control of the initial excitation.

[0040] The cross-section of the bistable interaction cavity expands nonlinearly along the fluid flow direction. Feedback channels have inlets and outlets on both side walls of the bistable interaction cavity. These feedback channels connect the downstream high-pressure region and the upstream low-pressure region of the bistable interaction cavity, forming a fluid pressure feedback loop.

[0041] In monitoring mode, the working fluid introduced through the main gas inlet forms a jet within the bistable interaction cavity. Due to the Coanda effect, the jet randomly adheres to one side wall of the bistable interaction cavity, causing a pressure increase in the feedback channel on the same side. The pressure wave is transmitted through the feedback channel to the jet root, pushing the jet to switch to the opposite side wall. The jet continuously undergoes high-frequency self-excited switching between the two sides of the bistable interaction cavity, resulting in periodic pressure pulsations in the fluid ejected from the expansion nozzle. The frequency of the pressure pulsations is determined by the length of the feedback channel and the geometry of the bistable interaction cavity, thus generating a frequency of [frequency value missing] within the tunnel space. Ultrasonic standing waves.

[0042] The fluid oscillator body also includes control jet channels symmetrically arranged on both sides of the inlet throat of the bistable interaction chamber. The control jet channels are connected to a control gas source. The inner wall of the expansion output nozzle is composed of a continuous Coanda surface.

[0043] In the blocking mode, a control fluid with a preset pressure difference is injected into the bistable interaction cavity through the control jet channel. The control fluid disrupts the self-excited oscillation feedback balance within the bistable interaction cavity, forcing the main jet to stably adhere to the Coanda surface on the lower pressure side. At this point, the jet stops oscillating and exits along the tangent direction of the Coanda surface, forming a high-momentum vector jet with a fixed deflection angle.

[0044] The electrostatic induction sensing device is a ring-shaped structure coaxially mounted around the outlet end of the expanding output nozzle. The electrostatic induction sensing device includes an array of induction electrodes, an insulating dielectric layer, and an electromagnetic shielding layer. The induction electrode array consists of several arc-shaped metal plates arranged at uniform intervals along the circumference.

[0045] An insulating dielectric layer is filled between the induction electrode array and the fluid oscillator body. An electromagnetic shielding layer covers the outer surface of the insulating dielectric layer and is connected to the mine grounding grid via a wire. The electromagnetic shielding layer is used to block non-electrostatic electromagnetic radiation from the tunnel environment.

[0046] The electrostatic sensitive field range of the inductive electrode array and the ultrasonic standing wave field range generated by the expanded output nozzle spatially overlap. When a charged fluid medium exists within this overlapping region, the charge in the fluid medium induces a charge on the inductive electrode array. Due to the periodic density fluctuations in the fluid medium caused by the ultrasonic standing wave field, the electrical signal output by the inductive electrode array contains a charge superimposed with the ultrasonic standing wave frequency. The corresponding amplitude modulation component.

[0047] The spectroscopic tomography detection device includes a laser emitting probe and a laser receiving probe. The laser emitting and receiving probes are installed at the cross-sectional location of the roadway where the electrostatic induction sensing device is located. Multiple sets of laser emitting and receiving probes form a cross-optical path grid covering the entire cross-section of the roadway. The cross-optical path grid passes through the acoustic pressure standing wave field region established by the fluid acoustic and jet generation devices.

[0048] The vector jet control mechanism provided by this invention is based on the expansion output nozzle structure of the fluid acoustic and jet generating device and the differential pressure regulation function of the control jet channel. The fluid acoustic and jet generating device is configured to adjust the injection vector direction of the main jet without changing the mechanical geometry.

[0049] The inner wall of the expansion nozzle includes a first sidewall and a second sidewall. At least one of the first and second sidewalls is a Coanda surface. The Coanda surface has a radius of curvature that increases monotonically along the fluid flow direction. The starting end of the Coanda surface smoothly transitions to the throat outlet of the bistable interaction chamber.

[0050] In jet blocking mode, the high-pressure fluid input from the main gas source inlet passes through the throat of the bistable interaction chamber, forming the main jet stream. The central control and demodulation unit sends a control signal to the electromagnetic proportional regulating valve connected to the inlet end of the control jet channel. The electromagnetic proportional regulating valve opens, injecting control fluid into one side of the bistable interaction chamber. The control fluid forms a transverse control jet perpendicular to the flow direction of the main jet stream.

[0051] The injection of the transverse control jet creates a fluid entrainment zone between the main jet and the Coanda surface. Due to the viscous entrainment of the fluid, the main jet carries away the fluid medium between it and the Coanda surface, resulting in a localized low-pressure zone. The pressure in this localized low-pressure zone is lower than the pressure near the sidewall of the expanding nozzle. Under the influence of the transverse pressure gradient, the main jet deflects towards the Coanda surface and flows stably onto its surface. When the main jet leaves the expanding nozzle, its velocity vector direction aligns with the tangential direction at the Coanda surface exit.

[0052] Deflection angle of the jet With the momentum flux of the control fluid and the momentum flux of the main jet The ratios exhibit a positive correlation function. The central control and demodulation unit adjusts the opening of the electromagnetic proportional control valve to change the pressure of the control fluid injected into the control jet channel, thereby regulating the momentum flux of the control fluid. With control of fluid momentum flux With the increase of [unclear], the position and length of the main jet's attachment point on the Coanda surface change, thus achieving the jet deflection angle. Continuous adjustment.

[0053] Multiple fluid acoustic and jet generating devices are arranged in a circular array along the circumferential wall of the mine roadway. During isolation operations, all devices synchronously switch to jet isolation mode. The central control and demodulation unit determines the target deflection angle based on calculated hazardous fluid velocity and pressure parameters and sends unified adjustment commands to the electromagnetic proportional control valves of all fluid acoustic and jet generating devices.

[0054] The high-energy jets emitted by the various fluid-induced acoustic and jet-generating devices simultaneously deflect towards the central axis of the tunnel. Multiple high-energy jets converge at a predetermined convergence point on the central axis of the tunnel. Due to the high velocity and high turbulence of the high-energy jets, the convergence and collision of these multiple jets create an inverted cone-shaped converging flow field on the tunnel cross-section.

[0055] The inverted cone-shaped converging flow field generates a high stagnation pressure zone at the convergence center, inducing the formation of annular aerodynamic closed vortex rings around the tunnel. The rotational flow direction of the aerodynamic closed vortex rings causes the fluid movement direction in the central region of the tunnel to be opposite to the intrusion direction of the hazardous fluid. The aerodynamic closed vortex rings construct an aerodynamic barrier covering the entire cross-section of the tunnel.

[0056] When hazardous fluid impacts an aerodynamic barrier, the axial dynamic pressure component generated by the aerodynamic barrier resists the impact dynamic pressure of the hazardous fluid. By adjusting the pressure of the control fluid in real time, the system dynamically changes the axial position of the jet convergence point and the pressure intensity of the aerodynamic closed vortex ring to match hazardous fluids with different flow velocities and pressures, thus achieving adaptive aerodynamic isolation of the hazardous fluid.

[0057] The spectroscopic tomography detection device, the fluid acoustic and jet generation device, and the electrostatic induction sensing device are arranged coaxially or adjacently in space.

[0058] The spectral tomography detection device includes multiple sets of laser emitting units, multiple sets of photoelectric receiving units, and an optical fiber transmission network. The laser emitting units and photoelectric receiving units are fixedly installed on the inner wall support structure of the mine roadway using explosion-proof brackets. The laser emitting units and photoelectric receiving units are distributed at predetermined angular intervals along the circumference of the roadway cross-section.

[0059] The laser emitting unit integrates a distributed feedback semiconductor laser and a thermoelectric cooling temperature control module. The laser emitting unit is configured to emit a tunable narrow-linewidth laser with a center wavelength matching the near-infrared characteristic absorption spectrum of the gas being measured. An optical collimating lens is located at the front end of the laser emitting unit, configured to shape the scattered light emitted by the laser emitting unit into a collimated beam with a divergence angle less than a preset threshold.

[0060] The photoelectric receiving unit integrates an indium gallium arsenide photodetector and a preamplifier circuit. The spectral response band of the photoelectric receiving unit covers the emission wavelength range of the laser emitting unit. The photoelectric receiving unit is configured to receive transmitted laser light passing through the tunnel monitoring area and convert the intensity signal of the transmitted laser light into a low-noise analog voltage signal.

[0061] The laser emitting unit and the photoelectric receiving unit form a fan-shaped intersecting optical path layout within the tunnel cross-section. The laser beam emitted by each laser emitting unit is projected onto multiple photoelectric receiving units located on the opposite side of the tunnel cross-section. These multiple laser beams intersect on the tunnel cross-section, forming a tomographic scanning grid covering the monitoring area. The spatial coverage of the tomographic scanning grid completely covers the acoustic pressure standing wave field region established by the fluid acoustic and jet generation devices.

[0062] The spectroscopic tomography detection device is connected to the central control and demodulation unit via an optical fiber transmission network. The optical fiber transmission network uses flame-retardant and explosion-proof optical cables. The central control and demodulation unit is configured to inject a driving current superimposed with a high-frequency sinusoidal modulation signal into the laser emitting unit to drive the laser emitting unit to perform wavelength modulation spectral scanning. The central control and demodulation unit receives the analog voltage signal output from the photoelectric receiving unit, extracts the second harmonic component from the analog voltage signal, and calculates the path integral concentration on each optical path.

[0063] The central control and demodulation unit is configured to run a gas distribution reconstruction algorithm. Using either an algebraic reconstruction algorithm or a synchronous iterative reconstruction algorithm, the central control and demodulation unit calculates the two-dimensional gas concentration distribution field within the tunnel cross-section based on the path integral concentration data of all optical paths in the tomographic scanning grid. This two-dimensional gas concentration distribution field characterizes the concentration gradient distribution of hazardous fluids in the tunnel space and the coordinates of high-concentration core regions.

[0064] The outer casing of the laser emitting unit and the photoelectric receiving unit is equipped with an annular air curtain purging mechanism at its front end. The annular air curtain purging mechanism includes an annular air passage and a micro-pore array located around the optical window. The annular air passage is connected to an external compressed air pipeline. The annular air curtain purging mechanism is configured to eject a positive pressure airflow through the micro-pore array, forming a high-speed air protective layer on the surface of the optical window to prevent coal dust or water mist from adhering to the optical window surface.

[0065] The multiphysics signal demodulation and intelligent identification method is executed by the central control and demodulation unit. The multiphysics signal demodulation and intelligent identification method includes the following steps:

[0066] Frequency domain feature extraction of acoustic-electric modulated signals

[0067] The central control and demodulation unit receives the induced current signal output by the electrostatic induction sensing device. Analog-to-digital conversion and Fast Fourier Transform (FFT) are performed to obtain the power spectral density function of the induced current signal. .

[0068] In the sound pressure standing wave field established by the fluid-induced acoustic and jet generation device, the sound pressure distribution is... Satisfies the wave equation:

[0069]

[0070] in, The sound pressure level is the amplitude. For sound wave number, The preset emission angular frequency for fluid acoustic and jet generation devices.

[0071] The central control and demodulation unit in the power spectral density function In the middle, with a preset transmission angular frequency Centered on the preset bandwidth range A peak search is performed internally.

[0072] The central control and demodulation unit extracts the maximum spectral peak energy value within this bandwidth range. and the actual peak frequency corresponding to the maximum spectral peak .

[0073] True / False Interference Identification Based on Acoustic-Electrical Coupling Characteristics

[0074] The central control and demodulation unit will determine the maximum spectral peak energy value. With the preset sound modulation energy threshold Compare them.

[0075] If the total energy of the induced current signal is greater than the background noise threshold, but the maximum spectral peak energy value Less than the acoustic modulation energy threshold The central control and demodulation unit determines that the induced current signal is an electromagnetic interference signal that is not modulated by acoustic waves, and performs a signal reset operation.

[0076] If the maximum spectral peak energy value Greater than the acoustic modulation energy threshold The central control and demodulation unit determines that there is a moving fluid medium modulated by sound waves in the monitoring area and triggers the flow velocity inversion calculation step.

[0077] Doppler velocity inversion

[0078] The central control and demodulation unit uses the Doppler effect principle to calculate the macroscopic flow velocity of the fluid medium. .

[0079] The movement of the fluid medium causes a drift in the modulation frequency of the sound wave on the charge density. The central control and demodulation unit adjusts the modulation frequency according to the actual peak frequency. With preset transmission angular frequency Deviation calculation of flow rate:

[0080]

[0081] in, The speed of sound in the mine environment. This is the preset angle between the fluid flow direction and the sound wave propagation direction.

[0082] Spectral Tomography Distribution Reconstruction

[0083] The central control and demodulation unit synchronously acquires the transmitted light intensity data of each optical path of the spectral tomography detection device.

[0084] The central control and demodulation unit discretizes the roadway monitoring sections into... A grid of pixels.

[0085] Based on the discretized form of the Beer-Lambert law, a system of linear equations relating the optical path integral density to the grid pixel density is established:

[0086]

[0087] in, To increase the intensity of emitted light, For the first The received light intensity of the optical path, For the first The light path passes through the first The geometric path length per grid pixel. For the first Gas concentration value per grid pixel, This represents the total number of pixels in the grid.

[0088] The central control and demodulation unit uses the Algebraic Reconstruction Algorithm (ART) or the Joint Iterative Reconstruction Algorithm (SIRT) to iteratively solve the linear equations and generate a two-dimensional gas concentration distribution matrix of the tunnel cross section.

[0089] The central control and demodulation unit extracts the maximum local concentration value from the two-dimensional gas concentration distribution matrix. .

[0090] Multi-criteria fusion and vector control command generation

[0091] The central control and demodulation unit reads the preset flow rate alarm threshold. and concentration alarm threshold .

[0092] When the condition is met and At that time, the central control and demodulation unit generates a trigger signal that is confirmed to be a dynamic disaster.

[0093] The central control and demodulation unit is based on the macroscopic flow velocity. Using a pre-defined hydrodynamic model, calculate the target jet deflection angle that can balance the momentum of the disaster fluid. .

[0094] The central control and demodulation unit queries the pre-stored mapping table of jet deflection angle and control pressure to determine the corresponding control fluid drive voltage value.

[0095] The central control and demodulation unit converts the control fluid drive voltage value into an electrical signal and sends it to the fluid acoustic and jet generation device.

[0096] This invention provides an integrated downhole disaster prevention method based on acoustic-fluid-electric modulation sensing and vector jet coordinated control. The integrated downhole disaster prevention method is jointly executed by a central control and demodulation unit coordinating a fluid acoustic and jet generation device, an electrostatic induction sensing device, and a spectral tomography detection device. The integrated downhole disaster prevention method includes the following steps:

[0097] Step S1: System initialization and sound field construction

[0098] The central control and demodulation unit sends a monitoring mode activation command to the fluid acoustic and jet generator. The main air source inlet of the fluid acoustic and jet generator receives low-pressure working fluid after pressure regulation. The fluid acoustic and jet generator utilizes a bistable interaction cavity to generate fluid self-excited oscillations and transmits a frequency of [frequency value missing] to the roadway monitoring area. The ultrasonic waves establish a background sound pressure standing wave field within the monitoring area. Simultaneously, the central control and demodulation unit drives the spectroscopic tomography detector to perform a baseline scan of the background gas concentration, acquiring background absorption spectral data under the current environment.

[0099] Step S2: Acquisition of acoustic-electric modulation signals

[0100] The electrostatic induction sensing device monitors the charge density fluctuations within the monitored area in real time. When a moving multiphase fluid appears in the tunnel, the electrostatic induction sensing device senses the static charge generated in the multiphase fluid due to the triboelectric effect. Modulated by the acoustic radiation pressure of the background sound pressure standing wave field, charged particles in the multiphase fluid generate charges at frequencies consistent with the sound waves. Synchronous periodic displacement. The electrostatic induction sensing device outputs an induced current signal superimposed with acoustic wave carrier characteristics to the central control and demodulation unit.

[0101] Step S3: Signal demodulation and physical field feature extraction

[0102] The central control and demodulation unit receives the induced current signal and performs frequency domain analysis. The central control and demodulation unit extracts the frequency domain value of the induced current signal. The central control and demodulation unit compares the peak energy and frequency shift at a given location. It then compares the peak energy with a preset acoustic modulation threshold. If the peak energy exceeds the threshold, the unit determines the signal source is a solid fluid and eliminates electromagnetic interference signals that do not contain acoustic modulation characteristics. Subsequently, the unit calculates the macroscopic flow velocity of the fluid using the Doppler effect formula based on the frequency shift.

[0103] Step S4: Simultaneous Tomography Verification

[0104] While calculating the macroscopic fluid velocity, the central control and demodulation unit triggers a high-frequency scan using a spectroscopic tomography device. The spectroscopic tomography device acquires transmitted light intensity data from multiple intersecting optical paths. The central control and demodulation unit processes the transmitted light intensity data using an algebraic reconstruction algorithm to generate a two-dimensional gas concentration distribution matrix for the tunnel cross-section. The central control and demodulation unit then extracts the gas composition types and maximum local concentration values ​​from the two-dimensional gas concentration distribution matrix.

[0105] Step S5: Multidimensional Criterion Fusion and Decision Making

[0106] The central control and demodulation unit logically compares the calculated macroscopic flow velocity and maximum local concentration values ​​with preset flow velocity safety thresholds and concentration safety thresholds, respectively. When the macroscopic flow velocity exceeds the flow velocity safety threshold and the maximum local concentration value exceeds the concentration safety threshold, the central control and demodulation unit generates a disaster prevention trigger signal.

[0107] Step S6: Vector jet blocking execution

[0108] The central control and demodulation unit calculates the reverse stagnation pressure required to resist the disaster fluid based on the macroscopic flow velocity, and determines the target jet deflection angle of the fluid acoustic and jet generating devices. The central control and demodulation unit queries a preset control voltage and deflection angle mapping table to determine the control voltage value corresponding to the target jet deflection angle.

[0109] The central control and demodulation unit sends a pressurization command to the main air source regulating valve of the fluid acoustic and jet generator, and sends a control voltage value to the electromagnetic proportional valve connected to the control jet channel. The main air source inlet pressure of the fluid acoustic and jet generator increases, while the control jet channel ejects a control fluid with a specific momentum flux. The control fluid utilizes the Coanda effect to force the main jet to adhere to the Coanda surface. Multiple high-energy jets ejected from the fluid acoustic and jet generators converge at a predetermined position on the central axis of the tunnel. The converging jets form an inverted conical aerodynamic closed vortex ring. The axial stagnant pressure generated by the inverted conical aerodynamic closed vortex ring provides spatial isolation for the invading hazardous fluid. The electromagnetic proportional regulating valve adopts an intrinsically safe explosion-proof design, and its driving voltage is output by the central control and demodulation unit through an isolation barrier.

[0110] Step S7: Dynamic Adaptive Adjustment and Reset

[0111] During the jet interception process, the electrostatic induction sensing device and the spectral tomography detection device continuously collect data on the velocity and concentration changes of the hazardous fluid. The central control and demodulation unit dynamically adjusts the control voltage output to the electromagnetic proportional valve based on real-time feedback data, correcting the jet deflection angle to maintain the stability of the inverted conical aerodynamic closed vortex ring. When the monitored fluid velocity and concentration drop below the safety threshold for a preset time, the central control and demodulation unit controls the fluid acoustic and jet generating devices to stop the high-energy jet and returns to the initial monitoring mode.

[0112] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0113] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An integrated equipment for multi-hazard sensing and intelligent emergency control in underground mines, characterized in that, include: A fluid acoustic and jet generating device arranged in a ring array is fixedly installed on the circumferential inner wall of a mine roadway and configured to construct a sound pressure standing wave field in monitoring mode and form an aerodynamic closed barrier in blocking mode. An electrostatic induction sensing device is located downstream of or integrated with the fluid acoustic and jet generation device, and is configured to non-contactly collect the charge density fluctuation signal of the fluid medium in the monitoring area; a spectral tomography detection device includes multiple sets of laser emitting ends and receiving ends arranged on the tunnel perimeter wall, and is configured to acquire gas absorption spectral data on the tunnel cross section. as well as The central control and demodulation unit is connected to the fluid acoustic and jet generation device, the electrostatic induction sensing device, and the spectral tomography detection device, respectively. The central control and demodulation unit is configured to: demodulate the charge density fluctuation signal to extract acoustic modulation features, determine whether there is a solid fluid modulated by acoustic waves based on the acoustic modulation features, calculate the gas concentration distribution by combining the gas absorption spectrum data, and generate a mode switching command for the fluid acoustic and jet generation device based on the determination result.

2. The integrated equipment for multi-hazard sensing and intelligent emergency control in downhole mines according to claim 1, characterized in that, The fluid acoustic and jet generating device includes a fluid oscillator body, and the fluid oscillator body has a connected flow channel structure inside. The flow channel structure includes, in sequence along the fluid flow direction: a main gas source inlet, a contraction nozzle section, a bistable interaction chamber, and an expansion output nozzle. The inner wall surface of the expansion output nozzle is formed by a Coanda surface; the fluid oscillator body also includes control jet channels symmetrically arranged on both sides of the inlet throat of the bistable interaction cavity; In the monitoring mode, the fluid acoustic and jet generating device uses the self-excited oscillation of the fluid in the bistable interaction cavity to emit ultrasonic waves of a preset frequency to the roadway monitoring area; In the blocking mode, the control jet channel injects control fluid to disrupt the self-excited oscillation in the bistable interaction cavity and uses the Coanda effect to deflect the main jet along the Coanda surface.

3. The integrated equipment for multi-hazard sensing and intelligent emergency control in downhole mines according to claim 2, characterized in that, The electrostatic induction sensing device is a ring structure coaxially mounted around the outlet end of the expanded output nozzle. The electrostatic induction sensing device includes: The induction electrode array consists of several arc-shaped metal plates evenly spaced along the circumference. An insulating dielectric layer is filled between the inductive electrode array and the fluid oscillator body; and An electromagnetic shielding layer is wrapped around the outer surface of the insulating dielectric layer and connected to the mine grounding grid via a wire.

4. The integrated equipment for multi-hazard sensing and intelligent emergency control in downhole mines according to claim 1, characterized in that, The method by which the central control and demodulation unit determines whether there is a solid fluid modulated by sound waves includes: The analog electrical signal output by the electrostatic induction sensing device is subjected to analog-to-digital conversion and fast Fourier transform to extract the power spectral density function of the analog electrical signal. In the power spectral density function, the maximum spectral peak energy value is extracted by searching for the preset emission angular frequency of the fluid acoustic and jet generation device. The maximum spectral peak energy value is compared with a preset acoustic modulation energy threshold. If the maximum spectral peak energy value is greater than the acoustic modulation energy threshold, it is determined that there is a solid fluid modulated by acoustic waves within the monitoring area.

5. The integrated equipment for multi-hazard sensing and intelligent emergency control in downhole mines according to claim 4, characterized in that, The central control and demodulation unit is also configured to calculate fluid velocity using the Doppler effect. Extract the actual peak frequency corresponding to the maximum spectral peak; The macroscopic velocity of the fluid medium is calculated based on the frequency offset between the actual peak frequency and the preset emission angular frequency, as well as the preset angle between the fluid flow direction and the sound wave propagation direction.

6. The integrated equipment for multi-hazard sensing and intelligent emergency control in downhole mines according to claim 1, characterized in that, The laser emitting end and receiving end of the spectral tomography detection device form an intersecting optical path grid covering the acoustic pressure standing wave field region within the tunnel cross section; The central control and demodulation unit is configured as follows: Discretize the tunnel monitoring section into a grid pixel matrix; Based on the discretized form of the Beer-Lambert law, a system of linear equations is established between the integral concentration of each optical path and the concentration of grid pixels. The linear equations are solved using an algebraic reconstruction algorithm or a joint iterative reconstruction algorithm to generate a two-dimensional gas concentration distribution matrix of the tunnel cross-section. Extract the maximum local concentration value from the two-dimensional gas concentration distribution matrix.

7. The integrated equipment for multi-hazard sensing and intelligent emergency control in downhole mines according to claim 6, characterized in that, The logic for the central control and demodulation unit to generate mode switching instructions is as follows: The macroscopic flow rate is compared with a preset flow rate alarm threshold, and the maximum local concentration value is compared with a preset concentration alarm threshold. When the macroscopic flow velocity is greater than the flow velocity alarm threshold and the maximum local concentration value is greater than the concentration alarm threshold, a blocking mode switching command is generated.

8. The integrated equipment for multi-hazard sensing and intelligent emergency control in downhole mines according to claim 2, characterized in that, The central control and demodulation unit performs vector jet control in the blocked mode: The target jet deflection angle that can balance the momentum of the disaster fluid is calculated based on the macroscopic flow velocity of the fluid medium; the corresponding control fluid drive voltage value is determined by querying the pre-stored jet deflection angle and control pressure mapping table. The control fluid drive voltage value is sent to the electromagnetic proportional regulating valve connected to the control jet channel to adjust the momentum flux ratio between the control fluid and the main jet, thereby controlling the wall attachment length of the main jet on the Coanda surface.

9. The integrated equipment for multi-hazard sensing and intelligent emergency control in downhole mines according to claim 2, characterized in that, In the aforementioned barrier mode, the high-energy jets ejected by multiple fluid acoustic and jet generating devices arranged in a ring array converge at a predetermined position on the central axis of the roadway, forming an inverted conical aerodynamic closed vortex ring. The axial stagnant pressure generated by the inverted conical aerodynamic closed vortex ring is in the opposite direction to the intrusion direction of the disaster fluid.

10. The integrated equipment for multi-hazard sensing and intelligent emergency control in downhole mines according to claim 6, characterized in that, The front end of the outer casing of the spectral tomography detection device is provided with an annular gas curtain purging mechanism. The annular air curtain blowing mechanism includes an annular air duct and a micro-pore array formed around the optical window. The annular air duct is connected to an external compressed air pipeline and is configured to eject positive pressure airflow through the micro-pore array and form an air protective layer on the surface of the optical window.

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