NMR explosion dynamic load multi-field coupling test device and method

Abstract

This invention relates to the field of experimental equipment technology, and particularly to an NMR combustion-explosion dynamic load multi-field coupling experimental device and method. The technical solution includes a control module, an impact module, a detection module, and a vibration reduction module; wherein, the control module includes an operating platform, a transmission line, an engine, a fuel tank, an oxygen tank, connecting pipes, a high-temperature resistant fuel nozzle, and a high-temperature and pressure resistant gas sealing pipe; the operating platform is located behind the engine. This invention achieves graded control of dynamic load through combustion-explosion-electromagnetic composite loading, integrates simultaneous detection of multiple physical fields such as nuclear magnetic resonance, acoustic waves, and resistivity, sets up multi-level vibration reduction and dissipation structures to absorb residual kinetic energy, adopts a high-temperature and high-pressure resistant sealing design to ensure safety, simulates ground temperature, ground stress, and pore fluid fields to reproduce the deep in-situ multi-field coupling environment, and is centrally controlled and automatically reset by the operating platform, thereby realizing a laboratory simulation of deep dynamic disasters with flexible and adjustable parameters.

Description

Technical Field

[0001] This invention relates to the field of experimental equipment technology, and in particular to an NMR combustion and explosion dynamic load multi-field coupling experimental device and method. Background Technology

[0002] As the depth of coal mining continues to increase, deep coal and rock masses are situated in complex environments characterized by high ground stress, high gas pressure, and strong mining disturbances, leading to frequent dynamic disasters such as rockbursts, rock bursts, and coal and gas outbursts. To reveal the disaster mechanisms of deep coal and rock masses under dynamic disturbances, laboratory physical simulation experiments have become an important research method.

[0003] Currently, various experimental devices exist for simulating dynamic disasters during deep mining, such as applying dynamic loads to coal and rock samples using mechanical hydraulic loading, pneumatic impact loading, or electromagnetic pulse loading. Some devices also integrate single or limited physical field monitoring methods such as acoustic emission, resistivity, or infrared thermography. However, existing experimental systems generally suffer from the following shortcomings:

[0004] (1) Single loading form: Most devices can only achieve dynamic loading in a single form of mechanical or electromagnetic, which is difficult to simulate the real complex stress environment of the coupling effect between combustion and explosion impact (such as gas explosion and blasting mining) and ground stress in deep strata.

[0005] (2) Poor controllability of loading rate and energy: Traditional combustion and explosion loading methods are often uncontrollable. The dynamic load intensity, frequency and waveform are difficult to adjust precisely, and it is impossible to achieve controllable superposition and energy staged release of combustion-electromagnetic composite dynamic load.

[0006] (3) Insufficient ability to monitor multiple physical fields simultaneously: Existing devices have obvious defects in the synchronous dynamic acquisition of multiple field parameters such as stress field, sound field, electric field, temperature field and pore structure evolution. In particular, they lack the combination with nuclear magnetic resonance (NMR) online detection technology, resulting in insufficient accuracy in the study of the pore fluid, fracture evolution and energy migration law inside coal and rock mass during the dynamic disaster incubation process.

[0007] (4) Weak energy damping and anti-interference capabilities: After impact loading, the remaining kinetic energy is prone to reverse impact or signal interference, affecting the stability of the equipment and the reliability of experimental data.

[0008] In summary, this application proposes an NMR combustion and explosion dynamic load multi-field coupling test device and method. Summary of the Invention

[0009] The purpose of this invention is to address the problems of existing test systems having a single loading mode and poor controllability of loading rate and energy in the background art, and to propose an NMR combustion and explosion dynamic load multi-field coupling test device and method.

[0010] In one aspect, this application provides an NMR combustion and explosion dynamic load multi-field coupling test device, including a control module, an impact module, a detection module and a vibration reduction module;

[0011] The control module includes an operating console, a transmission line, an engine, a fuel tank, an oxygen tank, connecting pipes, a high-temperature fuel nozzle, and a high-temperature and pressure-resistant gas sealing pipe. The operating console is located behind the engine. One end of the transmission line is connected to the operating console, and the other end is connected to the engine. The fuel tank and the oxygen tank are arranged side by side in front of the engine. The connecting pipes are connected to the fuel tank, the oxygen tank, and the high-temperature fuel nozzle, respectively. The inlet of the high-temperature and pressure-resistant gas sealing pipe is connected to the high-temperature fuel nozzle.

[0012] The impact module includes a high-pressure piston, a high-energy hydraulic sealing pipe, a dynamic load loading chamber, a fixed bracket, a pressure reducing plate, a buffer pressure reducing rod, and a clamp fixing head. The high-pressure piston is located at the outlet end of the high-temperature and pressure-resistant gas sealing pipe. The high-energy hydraulic sealing pipe is sealed to the high-pressure piston. The dynamic load loading chamber is located at the front end of the high-pressure piston and communicates with the high-energy hydraulic sealing pipe. The fixed bracket supports the dynamic load loading chamber from below. The pressure reducing plate is fixed to the side of the dynamic load loading chamber. One end of the buffer pressure reducing rod is fixedly connected to the pressure reducing plate, and the other end of the buffer pressure reducing rod is fixedly connected to the clamp fixing head.

[0013] The detection module includes an NMR detector, a clamp, an online mixed-frequency transmitter, an online mixed-frequency receiver, a confining-pressure ceramic coil, a surface fiber armor, and a high-frequency multipole tomographic resistor. The clamp's fixing head is installed on the head of the NMR detector, and the clamp is located in the middle of the detection cavity of the NMR detector. The online mixed-frequency transmitter and the online mixed-frequency receiver are respectively located on both sides of the NMR detector. The confining-pressure ceramic coil surrounds the outer layer of the detection cavity, the surface fiber armor covers the outside of the confining-pressure ceramic coil, and the high-frequency multipole tomographic resistor is fixed to the outer wall of the detection module.

[0014] The vibration damping module includes a pressure-reducing spring, a secondary vibration damping device, and an energy absorption block. The pressure-reducing spring is disposed between the NMR detector and the secondary vibration damping device. The secondary vibration damping device and the energy absorption block are connected in sequence. The pressure-reducing plate, buffer pressure-reducing rod, pressure-reducing spring, secondary vibration damping device, and energy absorption block are arranged in sequence along the loading direction to form a multi-stage vibration damping and energy dissipation structure.

[0015] Optionally, the control panel controls the start / stop and power of the engine via the transmission line. The gas output from the fuel tank and oxygen tank is mixed in the connecting pipe and then sent to the drive chamber of the high-pressure piston through the high-temperature fuel nozzle and the high-temperature and pressure-resistant gas sealing pipe.

[0016] Optionally, the device further includes a loading chamber, which is fixedly connected to the dynamic load chamber via a connecting plate and supported by the fixed bracket; the top of the loading chamber is provided with a support fixing head, and the NMR detector is fixed to the side of the support fixing head.

[0017] Optionally, the inner wall of the loading chamber is equipped with a displacement sensor and a pressure sensor, and heating resistor elements are installed at the four corners of the loading chamber. The loading chamber is made of high-strength alloy material.

[0018] Optionally, the online mixed-sound multi-frequency transmitter and the online mixed-sound multi-frequency receiver are symmetrically arranged on the left and right sides of the NMR detector, the confining pressure ceramic coil is a ring coil, and the surface fiber armor is a mesh cladding layer.

[0019] Optionally, the device further includes a lateral support component, which is disposed on the side of the device and connected to the fixed bracket.

[0020] Secondly, this application provides a multi-field coupling test method for NMR combustion and explosion dynamic load, applied to the NMR combustion and explosion dynamic load multi-field coupling test apparatus described in the first aspect, comprising the following steps:

[0021] a. Place the standard coal rock mass sample in the loading chamber, insert a gasket between the sample and the loading column, and tighten the sealing bolts to ensure the chamber is airtight;

[0022] b. Set the target static load, combustion and explosion pressure, and electromagnetic energy parameters through the control panel, and start the data acquisition system;

[0023] c. Control the pressurization pump to gradually apply load and establish an initial static stress field;

[0024] d. When fuel injection and ignition are initiated, the combustion chamber generates high-temperature and high-pressure gas that drives the high-pressure piston to move. At the same time, the electromagnetic impactor releases energy, forming a combustion-detonation-electromagnetic composite dynamic load.

[0025] e. The combined energy is transmitted to the sample via the force-transmitting piston and the dynamic load loading chamber to achieve instantaneous impact loading;

[0026] f. The detection module collects stress, sound wave, conductivity and temperature signals in real time and transmits them to the operating table;

[0027] g. After loading is completed, the damping module absorbs the remaining kinetic energy and the system resets; repeat steps a to f to simulate the dynamic response and catastrophe evolution process under different combustion and explosion intensities and stress environments.

[0028] Compared with the prior art, this application includes at least one of the following beneficial technical effects:

[0029] This invention realizes combined combustion and electromagnetic loading, and can control the loading rate and energy in stages to realistically simulate the complex dynamic loading environment in deep strata.

[0030] This invention integrates multiple detection methods such as nuclear magnetic resonance, acoustic waves, and resistivity, and can simultaneously collect multi-physical field signals such as stress, acoustic waves, resistivity, temperature, and pore structure during the impact process.

[0031] The present invention features a multi-stage damping and energy dissipation structure along the loading direction, which absorbs the remaining kinetic energy step by step and effectively protects the core testing equipment.

[0032] This invention employs a high-temperature and high-pressure resistant sealing design to form a sealed combustion and explosion chamber, preventing gas leakage and energy loss, and ensuring safety.

[0033] This invention simulates geothermal temperature, geostress, and pore fluid fields through heating, confining pressure, and nuclear magnetic resonance detection, and reproduces the deep in-situ multi-field coupling environment in the laboratory.

[0034] The present invention provides centralized control of test parameters via an operating console, the system can be automatically reset, test parameters are flexibly adjustable, and the method has strong repeatability.

[0035] In summary, this invention achieves graded dynamic load control through a combination of combustion-explosion and electromagnetic loading, integrates simultaneous detection of multiple physical fields such as nuclear magnetic resonance, acoustic waves, and resistivity, sets up multi-level damping and dissipation structures to absorb residual kinetic energy, adopts a high-temperature and high-pressure resistant sealing design to ensure safety, simulates ground temperature, ground stress, and pore fluid fields to reproduce the deep in-situ multi-field coupling environment, and is centrally controlled and automatically reset by an operating console, thereby realizing a laboratory simulation of deep dynamic disasters with flexible and adjustable parameters. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of an NMR combustion and explosion dynamic load multi-field coupling test device according to the present invention;

[0037] Figure 2 This is a control module diagram in an embodiment of the present invention;

[0038] Figure 3 This is a diagram of the impact module in an embodiment of the present invention;

[0039] Figure 4 This is a diagram of the detection module in an embodiment of the present invention;

[0040] Figure 5 This is a diagram of the shock absorption module in an embodiment of the present invention;

[0041] Figure 6 This is a cross-sectional structural diagram of an embodiment of the present invention.

[0042] In the diagram: 1. Control panel; 2. Transmission line; 3. Engine; 4. Fuel tank; 5. Oxygen tank; 6. Connecting pipe; 7. High-temperature fuel nozzle; 8. High-temperature and pressure-resistant gas sealing pipe; 9. High-pressure piston; 10. High-energy hydraulic sealing pipe; 11. Dynamic load chamber; 12. Fixed bracket; 13. Pressure reducing plate; 14. Buffer pressure reducing rod; 15. Clamp fixing head; 16. NMR detector; 17. Clamp; 18. Pressure reducing spring; 19. Secondary damping device; 20. Energy absorption block; 21. Online mixed-sound multi-frequency transmitter; 22. Online mixed-sound multi-frequency receiver; 23. Confining pressure ceramic coil; 24. Surface fiber armor; 25. High-frequency multi-pole tomographic resistor. Detailed Implementation

[0043] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0044] like Figures 1 to 6 As shown, this invention provides an NMR combustion-explosion dynamic load multi-field coupling test device, which includes a control module, an impact module, a detection module, and a vibration reduction module. These modules work together to simulate the dynamic response and catastrophic evolution of deep coal and rock masses under combustion-explosion dynamic loads and multi-physics field coupling under laboratory conditions.

[0045] like Figure 2 The control module is used to realize the supply of mixed gas, ignition control, and system operation. Specifically, the control module includes an operating panel 1, a transmission line 2, an engine 3, a fuel tank 4, an oxygen tank 5, a connecting pipe 6, a high-temperature resistant fuel nozzle 7, and a high-temperature resistant and pressure-resistant gas sealing pipe 8.

[0046] The control panel 1 is located behind the engine 3 and is used to set test parameters (such as target static load, combustion and explosion pressure, electromagnetic energy, etc.) and control the operation of the entire system. One end of the transmission line 2 is connected to the control panel 1, and the other end is connected to the engine 3 to transmit electrical signals. The engine 3 is located at the right end of the control panel 1 and serves as the power source for fuel injection. The fuel tank 4 and the oxygen tank 5 are arranged side by side at the front of the engine 3 and are used to store fuel and combustion oxygen, respectively. The connecting pipe 6 is connected to the fuel tank 4, the oxygen tank 5, and the high-temperature fuel nozzle 7, respectively, so that the fuel and oxygen are mixed in the connecting pipe 6. The outlet of the high-temperature fuel nozzle 7 is connected to the inlet of the high-temperature and pressure-resistant gas sealing pipe 8, which extends to the area where the high-pressure piston 9 is located, and is used to transport the mixed combustion gas to the combustion and explosion chamber.

[0047] like Figure 3 The impact module is used to generate and transmit the dynamic load of combustion and explosion, and includes a high-pressure piston 9, a high-energy hydraulic sealing pipe 10, a dynamic load loading chamber 11, a fixed bracket 12, a pressure reducing plate 13, a buffer pressure reducing rod 14, and a clamp fixing head 15.

[0048] The high-pressure piston 9 is located at the outlet end of the high-temperature and pressure-resistant gas-sealed pipe 8 and can move axially under the impingement of the explosive gas. The high-energy hydraulic sealing pipe 10 is sealed to the high-pressure piston 9 to form a sealed high-pressure chamber during combustion and explosion. The dynamic load chamber 11 is located at the front end of the high-pressure piston 9 and communicates with the high-energy hydraulic sealing pipe 10 to receive the impact energy transmitted by the high-pressure piston 9. The fixed bracket 12 is supported below the dynamic load chamber 11 to ensure the stability of the device during loading. The pressure reducing plate 13 is fixed to the side of the dynamic load chamber 11, and one end of the buffer pressure reducing rod 14 is fixedly connected to the pressure reducing plate 13, and the other end is fixedly connected to the clamp fixing head 15 to smoothly transmit the impact force to the detection module.

[0049] like Figure 4 The detection module is used to acquire multi-physics field signals of the sample in real time during the loading process, including an NMR detector 16, a clamp 17, an online mixed-sound multi-frequency transmitter 21, an online mixed-sound multi-frequency receiver 22, a confining pressure ceramic coil 23, a surface fiber armor 24, and a high-frequency multipole tomographic resistor 25.

[0050] like Figures 3-6The clamping head 15 is mounted on the head of the NMR detector 16. The clamp 17 is located in the middle of the detection cavity of the NMR detector 16 and is used to fix the coal and rock mass sample. The online mixed-sound multi-frequency transmitter 21 and the online mixed-sound multi-frequency receiver 22 are respectively set on both sides of the NMR detector 16 and are used to transmit and receive acoustic signals to obtain the acoustic response characteristics of the sample under dynamic load. The confining pressure ceramic coil 23 is surrounded by the outer layer of the detection cavity to provide a stable magnetic field environment and cooperate with the NMR detector 16 to monitor the changes in pore structure and fluid distribution inside the sample in real time. The surface fiber armor 24 covers the outside of the confining pressure ceramic coil 23 to protect the coil and transmit signals. The high-frequency multipole tomographic resistive element 25 is fixed on the outer wall of the detection module to collect the resistivity signal of the sample in layers and perform tomographic imaging analysis through the operating table 1.

[0051] like Figure 5 The damping module is used to absorb the remaining kinetic energy after the loading is completed, preventing damage to the equipment from reverse impact. The damping module includes a pressure-reducing spring 18, a secondary damping device 19, and an energy-absorbing block 20.

[0052] The pressure-reducing spring 18 is disposed between the NMR detector 16 and the secondary damping device 19. The secondary damping device 19 is sequentially connected to the energy absorption block 20. The pressure-reducing plate 13, the buffer pressure-reducing rod 14, the pressure-reducing spring 18, the secondary damping device 19, and the energy absorption block 20 are arranged sequentially along the loading direction to form a multi-stage damping and energy dissipation structure. When the impact energy is transmitted to the end, it is absorbed in stages through the elastic deformation of the pressure-reducing spring 18, the damping dissipation of the secondary damping device 19, and the plastic deformation of the energy absorption block 20.

[0053] As a further improvement, the device also includes a loading chamber (not directly labeled in the figure). The loading chamber is fixedly connected to the dynamic load chamber 11 via a connecting plate and supported by the fixed bracket 12. A support fixing head is provided at the top of the loading chamber, and the NMR detector 16 is fixed to the side of the support fixing head. Displacement sensors and pressure sensors are provided on the inner wall of the loading chamber for real-time monitoring of the deformation and stress of the sample. Heating resistance elements are installed at the four corners of the loading chamber to simulate the temperature environment of deep strata. The loading chamber is made of high-strength alloy material to ensure structural safety under high-pressure combustion and explosion conditions.

[0054] In addition, the device may also include a lateral support component, which is disposed on the side of the device and connected to the fixed bracket 12 to further improve the overall rigidity.

[0055] The following describes in detail the application method of the NMR combustion and explosion dynamic load multi-field coupling test device of the present invention, based on the above structure, including the following steps:

[0056] Step a: Sample installation and sealing

[0057] Place the standard coal and rock mass sample in the loading chamber, ensuring close contact between the sample and the end face of the dynamic load chamber 11. Insert a protective gasket between the sample and the loading column to ensure uniform force distribution. Tighten the sealing bolts, check for leaks at the interface between the high-temperature and high-pressure resistant gas sealing pipe 8 and the high-pressure piston 9, close the safety valve, and ensure the airtightness of the entire combustion chamber and detection chamber.

[0058] Step b: Parameter settings and data acquisition startup

[0059] The target static load value, combustion and explosion pressure value, electromagnetic energy parameters, and simulated ground temperature value required for the test are set through the control panel 1. At the same time, the data acquisition system is started, so that the NMR detector 16, the online mixed-sound multi-frequency transmitter 21, the online mixed-sound multi-frequency receiver 22, the confining pressure ceramic coil 23, and the high-frequency multi-pole tomographic resistor 25 are put into the acquisition state.

[0060] Step c: Establishment of the initial static stress field

[0061] The pressure pump is controlled to gradually load the sample, and a static load is applied to the sample through the hydraulic system until the target static load value set in step b is reached, thereby simulating the initial geostress environment of the deep strata.

[0062] Step d: Generation of combustion-explosion-electromagnetic composite dynamic load

[0063] Engine 3 is started, and fuel tank 4 and oxygen tank 5 respectively output fuel and oxygen. After mixing in connecting pipe 6, they are sent to the drive chamber of high-pressure piston 9 through high-temperature resistant fuel nozzle 7 and high-temperature resistant and pressure-resistant gas sealing pipe 8. The mixture is ignited, and the high-temperature and high-pressure gas generated by combustion and explosion drives high-pressure piston 9 to move at high speed. At the same time, electromagnetic impactor (not shown in the figure) releases electromagnetic energy, forming a composite dynamic load of combustion and explosion and electromagnetic superposition.

[0064] Step e: Instantaneous impact loading

[0065] The impact energy of the high-pressure piston 9 is transmitted to the dynamic load chamber 11 via the high-energy hydraulic sealing pipe 10, and then from the dynamic load chamber 11 to the end face of the sample, achieving instantaneous impact loading. The fixed bracket 12 and the pressure reducing plate 13 ensure that the impact force is transmitted smoothly along the axial direction.

[0066] Step f: Real-time acquisition of multi-physics field signals

[0067] Throughout the impact loading process, the detection modules operate synchronously: the NMR detector 16 monitors the changes in pore structure and fluid distribution within the sample in real time; the online resonant multi-frequency transmitter 21 and the online resonant multi-frequency receiver 22 record the propagation characteristics of the stress wave; the confining pressure ceramic coil 23 and the surface fiber optic armor 24 provide a stable magnetic field and signal transmission; and the high-frequency multipole tomographic resistivity sheet 25 collects resistivity signals layer by layer. All of the above signals are fed back to the operating console 1 via transmission line 2 for real-time display, storage, and processing.

[0068] Step g: Vibration damping and system reset

[0069] After loading is completed, the remaining impact energy is absorbed and dissipated in stages through the pressure reducing plate 13, buffer pressure reducing rod 14, pressure reducing spring 18, secondary shock absorption device 19, and energy absorption block 20, preventing reverse impact from damaging the NMR detector 16 and other precision components. The system automatically resets and can be tested again after cooling.

[0070] By repeating steps a to g above, and adjusting different combustion and explosion intensities, static load levels, and electromagnetic energy parameters in step b, the dynamic response and catastrophic evolution of deep coal and rock masses under different working conditions can be simulated, providing reliable experimental data for studying the gestation mechanism and prevention and control technology of dynamic disasters such as rockbursts and rock bursts.

[0071] It is worth noting that this invention combines combustion-explosion loading with electromagnetic impact loading. The control module's operating panel 1, engine 3, fuel tank 4, and oxygen tank 5 precisely adjust the mixed gas ratio and ignition timing. Simultaneously, with the assistance of the electromagnetic impactor, a combined combustion-explosion and electromagnetic dynamic load is formed. Compared to single mechanical or electromagnetic loading methods, this invention can achieve higher energy density and a wider frequency range for dynamic load output, with a high loading rate and graded energy control, realistically reproducing extreme dynamic load conditions such as gas explosions and blasting mining in deep strata.

[0072] This invention integrates an NMR detector 16, an online mixed-sound multi-frequency transmitter 21, an online mixed-sound multi-frequency receiver 22, a confining pressure ceramic coil 23, a surface fiber optic armor 24, and a high-frequency multipole tomographic resistive analyzer 25. It can simultaneously acquire multi-physics field signals such as stress, acoustic waves, resistivity, temperature, and pore structure evolution of the sample during combustion and explosion impact. The NMR detector 16 monitors the changes in fluid and pore size within the sample in real time, the online mixed-sound multi-frequency transmitter 21 and receiver 22 capture stress wave propagation characteristics, and the high-frequency multipole tomographic resistive analyzer 25 achieves resistivity layered imaging. This multi-parameter fusion analysis provides unprecedented data support for studying the dynamic disaster initiation mechanism of coal and rock masses.

[0073] Furthermore, this invention incorporates a pressure-reducing plate 13, a buffer pressure-reducing rod 14, a pressure-reducing spring 18, a secondary damping device 19, and an energy-absorbing block 20 arranged sequentially along the loading direction at the end of the loading path, forming a multi-stage damping and energy dissipation structure. The remaining impact energy is first dispersed by the pressure-reducing plate 13, then transmitted to the pressure-reducing spring 18 via the buffer pressure-reducing rod 14 for elastic absorption, subsequently damped and dissipated by the secondary damping device 19, and finally completely absorbed by the energy-absorbing block 20 through plastic deformation. This structure effectively prevents reverse impacts from damaging high-precision components such as the NMR detector 16, significantly improving the stability and service life of the equipment.

[0074] This invention employs a high-temperature resistant fuel nozzle 7 and a high-temperature resistant and pressure-resistant gas sealing pipe 8, combined with a high-energy hydraulic sealing pipe 10, to form a sealed combustion and explosion chamber. This ensures that the high-temperature and high-pressure gas generated by the combustion and explosion is entirely used to drive the high-pressure piston 9, avoiding leakage and energy loss. Simultaneously, the fixed bracket 12 and lateral support components improve the overall structural rigidity, ensuring operational safety under extreme loading conditions. This invention simulates the geothermal field using heating resistance elements installed at the four corners of the loading chamber, and simulates the geostress and pore fluid field using confining pressure ceramic coils 23 and NMR detectors 16. Combined with combustion-explosion-electromagnetic composite dynamic load, it can highly reproduce the complex environment of high stress, high temperature, high dynamic load, and multi-field coupling in deep strata under laboratory conditions. The experimental results have direct guiding significance for the mechanism research and prevention and control technology verification of dynamic disasters such as rockburst, rock burst, and coal and gas outburst in deep mining.

[0075] In summary, this invention effectively overcomes the technical bottlenecks of existing deep dynamic disaster testing devices, such as single loading mode, insufficient multi-field monitoring, and poor energy absorption, and provides an advanced experimental platform for the study of dynamic disasters induced by deep coal-bearing resource development.

[0076] The above specific embodiments are merely several optional embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A multi-field coupling test apparatus for NMR combustion and explosion dynamic loads, characterized in that, It includes a control module, an impact module, a detection module, and a shock absorption module; The control module includes an operating console (1), a transmission line (2), an engine (3), a fuel tank (4), an oxygen tank (5), a connecting pipe (6), a high-temperature fuel nozzle (7), and a high-temperature and pressure-resistant gas sealing pipe (8). The operating console (1) is located behind the engine (3). One end of the transmission line (2) is connected to the operating console (1), and the other end is connected to the engine (3). The fuel tank (4) and the oxygen tank (5) are arranged side by side in front of the engine (3). The connecting pipe (6) is connected to the fuel tank (4), the oxygen tank (5), and the high-temperature fuel nozzle (7) respectively. The inlet of the high-temperature and pressure-resistant gas sealing pipe (8) is connected to the high-temperature fuel nozzle (7). The impact module includes a high-pressure piston (9), a high-energy hydraulic sealing pipe (10), a dynamic load loading chamber (11), a fixed bracket (12), a pressure reducing plate (13), a buffer pressure reducing rod (14), and a clamp fixing head (15). The high-pressure piston (9) is located at the outlet end of the high-temperature and pressure-resistant gas sealing pipe (8). The high-energy hydraulic sealing pipe (10) is sealed to the high-pressure piston (9). The dynamic load loading chamber (11) is located at the front end of the high-pressure piston (9) and communicates with the high-energy hydraulic sealing pipe (10). The fixed bracket (12) is supported below the dynamic load loading chamber (11). The pressure reducing plate (13) is fixed to the side of the dynamic load loading chamber (11). One end of the buffer pressure reducing rod (14) is fixedly connected to the pressure reducing plate (13), and the other end of the buffer pressure reducing rod (14) is fixedly connected to the clamp fixing head (15). The detection module includes an NMR detector (16), a clamp (17), an online mixed-sound multi-frequency transmitter (21), an online mixed-sound multi-frequency receiver (22), a confining-pressure ceramic coil (23), a surface fiber armor (24), and a high-frequency multipole tomographic resistor (25). The clamp fixing head (15) is installed on the head of the NMR detector (16), the clamp (17) is located in the middle of the detection cavity of the NMR detector (16), the online mixed-sound multi-frequency transmitter (21) and the online mixed-sound multi-frequency receiver (22) are respectively arranged on both sides of the NMR detector (16), the confining-pressure ceramic coil (23) surrounds the outer layer of the detection cavity, the surface fiber armor (24) covers the outside of the confining-pressure ceramic coil (23), and the high-frequency multipole tomographic resistor (25) is fixed to the outer wall of the detection module. The damping module includes a pressure-reducing spring (18), a secondary damping device (19), and an energy-absorbing block (20). The pressure-reducing spring (18) is disposed between the NMR detector (16) and the secondary damping device (19). The secondary damping device (19) and the energy-absorbing block (20) are connected in sequence. The pressure-reducing plate (13), the buffer pressure-reducing rod (14), the pressure-reducing spring (18), the secondary damping device (19), and the energy-absorbing block (20) are arranged in sequence along the loading direction to form a multi-level damping and energy dissipation structure.

2. The NMR combustion and explosion dynamic load multi-field coupling test device according to claim 1, characterized in that, The control panel (1) controls the start-stop and power of the engine (3) through the transmission line (2). The gas output from the fuel tank (4) and oxygen tank (5) is mixed in the connecting pipe (6) and then sent to the drive chamber of the high-pressure piston (9) through the high-temperature fuel nozzle (7) and the high-temperature and pressure resistant gas sealing pipe (8).

3. The NMR combustion and explosion dynamic load multi-field coupling test device according to claim 1, characterized in that, The device also includes a loading chamber, which is fixedly connected to the dynamic load chamber (11) via a connecting plate. The loading chamber is supported by the fixed bracket (12). The top of the loading chamber is provided with a support fixing head, and the NMR nuclear magnetic detector (16) is fixed to the side of the support fixing head.

4. The NMR combustion and explosion dynamic load multi-field coupling test device according to claim 3, characterized in that, The inner wall of the loading chamber is equipped with displacement sensors and pressure sensors, and heating resistor elements are installed at the four corners of the loading chamber. The loading chamber is made of high-strength alloy material.

5. The NMR combustion and explosion dynamic load multi-field coupling test device according to claim 1, characterized in that, The online mixed-sound multi-frequency transmitter (21) and the online mixed-sound multi-frequency receiver (22) are symmetrically arranged on the left and right sides of the NMR detector (16). The confining pressure ceramic coil (23) is a ring coil, and the surface fiber armor (24) is a mesh cladding layer.

6. The NMR combustion and explosion dynamic load multi-field coupling test device according to claim 1, characterized in that, The device also includes a lateral support component, which is disposed on the side of the device and connected to the fixed bracket (12).

7. A method for NMR combustion and explosion dynamic load multi-field coupling test, applied to the NMR combustion and explosion dynamic load multi-field coupling test apparatus according to any one of claims 1-6, characterized in that, Includes the following steps: a. Place the standard coal rock mass sample in the loading chamber, insert a gasket between the sample and the loading column, and tighten the sealing bolts to ensure the chamber is airtight; b. Set the target static load, combustion and explosion pressure and electromagnetic energy parameters through the control panel (1) and start the data acquisition system; c. Control the pressurization pump to gradually apply load and establish an initial static stress field; d. Start fuel injection and ignition, the combustion chamber generates high temperature and high pressure gas to drive the high pressure piston (9) to move, and at the same time the electromagnetic impactor releases energy to form a combustion-magnetic composite dynamic load; e. The composite energy is transmitted to the sample via the force-transmitting piston and the dynamic load loading chamber (11) to achieve instantaneous impact loading; f. The detection module collects stress, sound wave, electrical conductivity and temperature signals in real time and transmits them to the operating table (1). g. After loading is completed, the damping module absorbs the remaining kinetic energy and the system resets; repeat steps a to f to simulate the dynamic response and catastrophe evolution process under different combustion and explosion intensities and stress environments.

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