A dynamic simulation system and method for coupling disasters of coal mine fire and gas explosion

Abstract

The present application relates to the technical field of coal mine safety engineering, and particularly relates to a coal mine fire and gas explosion coupling disaster dynamic simulation system and method. The system comprises an explosion cavity composed of a primary explosion cavity, an explosion propagation roadway and a secondary explosion cavity; a gas loading system connected with the primary explosion cavity through a gas guide pipe, used for providing experimental gas; a dynamic regulation and control air leakage system connected with the primary explosion cavity through a porous air supply pipeline, used for providing air leakage; a thermal energy excitation system arranged inside the primary explosion cavity, used for providing a heat source and a fire source; a sensor monitoring system, used for collecting physical parameter and gas sample data; a pressure relief and gas disposal system, used for safe pressure relief and waste gas treatment; and an intelligent monitoring system, used for collecting experimental data for analysis and processing. The present application can realize automatic and intelligent control and simulation, greatly restore the occurrence process of the coal mine fire and gas coupling disaster, and dynamically monitor and analyze the disaster evolution law.

Description

Technical Field

[0001] This invention relates to the field of coal mine safety engineering technology, specifically to a dynamic simulation system and method for coupled disasters of coal mine fire and gas explosion. Background Technology

[0002] Coal has always occupied a dominant position in my country's energy structure, and therefore, its related safety issues have always been of great concern. Coal spontaneous combustion and gas coupling disasters pose a significant threat to coal mine safety. Due to the complex underground environment, the detection and prediction of coal spontaneous combustion in goaf areas remain difficult. Moreover, coal fire and gas coupling disasters have complex characteristics. When spontaneous combustion occurs in the coal left in the goaf after mining, a large amount of gas is released as the coal temperature rises. These gases and high-temperature ignition sources reach the critical value for gas explosion under oxygen concentration, resulting in serious consequences and economic losses. Such coupling disasters are particularly prominent in deep mining and complex geological conditions. Therefore, it is necessary to conduct in-depth research on the dynamic simulation law of coal fire and gas coupling disasters in order to determine the method for identifying dangerous areas of such disasters.

[0003] In the coupled process of coal spontaneous combustion-induced gas explosion, flame propagation and ignition criteria are key aspects, involving the flammability range and ignition conditions of the mixed gas. The explosive limits of methane in air are approximately 5-15%. When the gas concentration in the goaf is within this range and there is an ignition source, the methane flame can propagate sustainably and trigger an explosion. Therefore, determining the risk of a gas explosion requires checking whether the local methane concentration falls within the explosive limit range and whether the oxygen concentration is sufficient. Meanwhile, the minimum temperature at which a gas mixture can ignite without an open flame is approximately 537°C. When the heat source temperature generated by the spontaneous combustion of residual coal in the goaf exceeds this value and the surrounding methane concentration is within the explosive range, it may spontaneously ignite the gas, triggering the first explosion. The first gas explosion may disturb the environment, triggering a secondary coal dust explosion or delaying a second gas explosion. This necessitates studying whether a new combustible mixture reaches the critical conditions.

[0004] Existing studies mostly employ single-index predictions (such as gas concentration and temperature threshold) or static models, which are insufficient to reflect the dynamic coupling process between coal spontaneous combustion and gas release. Among existing technologies, some scholars have established symbiotic models between coal spontaneous combustion and gas in goaf areas, analyzing the main causes of gas explosions, but lacking the influence of coal spontaneous combustion temperature. Therefore, some scholars have further established gas movement models in goaf areas based on this. Additionally, experimental testing and numerical analysis methods have been used to study coal spontaneous combustion in goaf areas. However, coal spontaneous combustion is the result of complex multi-factor and multi-field coupled evolution, and there is still a lack of targeted and accurate research on the laws governing multi-factor coupled evolution. This requires continuous exploration and discovery through experimental methods.

[0005] Current research on coupled disasters of coal mine fire and gas explosion faces at least the following problems: Existing technologies lack sufficient dynamic simulation studies of systemic coupled disasters of coal mine fire and gas, making it impossible to effectively and accurately predict their occurrence; exploration of the multi-field evolution patterns of goaf areas under multi-factor coupling conditions is insufficient, especially regarding secondary explosions caused by a primary explosion in a focused goaf area; precise location and intelligent targeted treatment of coupled disaster areas of coal spontaneous combustion and gas are lacking; data fusion and analysis are difficult; and the application and integration of intelligent monitoring systems are not yet perfect. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a dynamic simulation system for coupled coal mine fire and gas explosion disasters. The system includes an explosion chamber consisting of a primary explosion chamber, an explosion propagation roadway, and a secondary explosion chamber; a gas loading system connected to the primary explosion chamber via a gas delivery pipe to provide experimental gas; a dynamically controlled air leakage system connected to the primary explosion chamber via a distributed porous air supply pipeline to provide air leakage; a thermal energy activation system deployed inside the primary explosion chamber to provide heat and ignition sources; a sensor monitoring system for collecting physical parameters and gas sample data; a pressure relief and gas disposal system for safe pressure relief and waste gas treatment; and an intelligent monitoring system for collecting and analyzing experimental data. This invention enables automated and intelligent control and simulation, greatly reproducing the occurrence process of coupled coal mine fire and gas disasters, and dynamically monitoring and analyzing the evolution of the disaster.

[0007] The present invention adopts the following technical solution: a dynamic simulation system for coupled disasters of coal mine fire and gas explosion, comprising: an explosion cavity, a gas loading system, a dynamic control and leakage system, a thermal energy activation system, a sensor monitoring system, a pressure relief and gas disposal system, and an intelligent monitoring system;

[0008] The explosion cavity includes a primary explosion cavity, an explosion propagation tunnel, and a secondary explosion cavity;

[0009] The gas loading system is connected to the primary explosion chamber via a gas delivery pipe and includes a gas supply cylinder group, an inlet valve, a gas delivery pipe, a sealing cap, a concentration regulator, and a gas mixing cylinder, used to supply and maintain a set concentration of experimental gas to the primary explosion chamber.

[0010] The dynamic air leakage control system is connected to the primary explosion cavity through a distributed porous air supply pipeline, and includes a variable frequency fan, an air leakage valve and a flow meter, for providing air leakage with a controllable flow rate to the primary explosion cavity;

[0011] The thermal energy activation system is installed inside the primary explosion cavity and includes a high-temperature loading device and an ignition device, used to provide a heat source and an ignition source for the coal sample inside the primary explosion cavity.

[0012] The sensor monitoring system, deployed in the primary explosion chamber and the secondary explosion chamber, includes a gas sampling pipeline, a temperature sensor, a pressure sensor, and a gas sensor, and is used to collect physical parameters and gas sample data of the primary explosion chamber and the secondary explosion chamber in real time during the experiment.

[0013] The pressure relief and gas disposal system includes a pressure relief valve, a rubber ball, a gas chromatograph, and a waste gas treatment device, which is used for safe pressure relief and waste gas treatment after the simulation experiment.

[0014] The intelligent monitoring system is used to collect and analyze the data gathered by various systems during the simulation experiment.

[0015] Furthermore, the interior of the primary explosion cavity employs a multi-layered filling structure, which includes:

[0016] The distributed porous air supply pipeline laid at the bottom of the primary explosion cavity;

[0017] A caving zone filling layer is provided above the distributed porous air supply duct, which is filled with crushed stone and coal gangue;

[0018] A crack filling layer is provided above the collapse zone filling layer, and is filled with gypsum board.

[0019] Furthermore, the dynamic air leakage control system includes:

[0020] The distributed multi-hole air supply duct adopts an equally spaced pore structure to control the leakage valve so that the variable frequency fan outputs different leakage rates;

[0021] A flow meter is used to monitor the flow rate in leaky ductwork in real time.

[0022] Furthermore, the thermal energy excitation system includes:

[0023] A high-temperature loading device, comprising a temperature controller and an infrared radiation heating device;

[0024] The infrared radiation heating device is used to provide a heat source for the cavity inside the primary explosion.

[0025] The temperature controller is used to regulate the heating temperature of the infrared radiation heating device;

[0026] An ignition device, including an ignition electrode and an ignition device, is used to remotely control the ignition device to trigger the ignition electrode to ignite when the concentration of the experimental gas in the primary explosion chamber reaches a set value.

[0027] Furthermore, in the sensor monitoring system, a gas extraction pipeline is installed in the coal powder fissures of the primary explosion chamber to extract the gas inside the primary explosion chamber.

[0028] Furthermore, the pressure relief and gas handling system includes:

[0029] A rubber ball installed at the outlet of the pressure relief valve is used to collect the reaction gases after the explosion.

[0030] A gas chromatograph is connected to the gas sampling line for concentration analysis of the gas extracted in the gas sampling line.

[0031] Waste gas treatment device, used to adsorb and purify residual waste gas.

[0032] Furthermore, the intelligent monitoring system includes:

[0033] Observation windows are respectively set up outside the primary explosion cavity, outside the explosion propagation tunnel, and outside the secondary explosion cavity, and monitoring camera probes are placed in the observation windows;

[0034] The data signal processor is communicatively connected to the sensor monitoring system and is used to process the data collected by the sensor monitoring system and send it to the intelligent visual platform.

[0035] This invention also proposes a dynamic simulation method for coupled coal mine fire and gas explosion disasters, applicable to any of the dynamic simulation systems for coupled coal mine fire and gas explosion disasters as described above. The method includes:

[0036] An explosion cavity is constructed to simulate the collapse zone and fracture zone of a goaf; the explosion cavity includes a primary explosion cavity and a secondary explosion cavity connected by an explosion propagation roadway;

[0037] The primary explosion chamber is injected with a set concentration of experimental gas and provided with a set rate of air leakage;

[0038] The coal sample inside the primary explosion chamber is heated to obtain real-time physical parameters and gas sample data in the primary explosion chamber;

[0039] When the physical parameters and gas sample data in the primary explosion chamber meet the set conditions for a primary explosion, a gas explosion is triggered inside the primary explosion chamber.

[0040] After a gas explosion is triggered inside the primary explosion chamber, real-time physical parameters and gas sample data in the secondary explosion chamber are obtained.

[0041] Based on the real-time physical parameters and gas sample data inside the secondary explosion cavity, determine whether the conditions for a secondary explosion are met.

[0042] Based on real-time physical parameters and gas sample data collected from the primary and secondary explosion chambers, quantitative relationship maps and dynamic parameters are generated to characterize the evolution of the disaster.

[0043] Furthermore, determining whether the conditions for a secondary explosion are met specifically includes:

[0044] Obtain the ambient temperature inside the secondary explosion cavity and determine whether the ambient temperature is higher than 700℃;

[0045] Obtain gas concentration data within the secondary explosion cavity to determine whether the gas concentration is within the 5%-15% range;

[0046] Obtain the coal dust concentration inside the secondary explosion cavity and determine whether the coal dust concentration is greater than 50 g / m³;

[0047] When all of the above conditions are met, it is determined that the internal conditions for a secondary explosion are met.

[0048] The beneficial effects of this invention are as follows: In the design of the explosion chamber of this invention, the primary explosion chamber, through a three-layer filling design in the vertical direction, can simulate the collapse zone and fracture zone inside the goaf. The design of the explosion propagation roadway and the secondary explosion chamber can simulate the flame and gas propagation path after the primary explosion. The overall structural design makes the simulation experiment more closely resemble the real environment. The distributed porous air supply pipeline laid at the bottom of the primary explosion chamber can ensure that the gas and airflow are released evenly in the chamber, preventing accumulation, thereby improving the accuracy and repeatability of the simulation. At the same time, the sensor monitoring system and intelligent monitoring system set in the system can realize automated and intelligent control and simulation, greatly restoring the occurrence process of coal mine fire and gas coupling disaster, and can dynamically monitor and analyze the evolution law of disaster, providing disaster risk early warning and prevention and control strategy support. The system of this invention also adopts multiple safety control measures, such as the thermal energy ignition system which can be remotely operated for ignition, and the pressure relief and gas disposal system which can adsorb and purify residual waste gas to ensure the safety of the experimental process. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is a schematic diagram of the framework of a dynamic simulation system for coupled disasters of coal mine fire and gas explosion according to an embodiment of the present invention;

[0051] Figure 2 This is a schematic diagram of a dynamic simulation system for coupled disasters of coal mine fire and gas explosion according to an embodiment of the present invention;

[0052] Figure 3 This is a cross-sectional view of a primary explosion cavity according to an embodiment of the present invention;

[0053] Figure 4 This is a schematic diagram of an observation window according to an embodiment of the present invention;

[0054] Figure 5 This is a schematic diagram of the planar structure of the ignition electrode in an ignition device according to an embodiment of the present invention;

[0055] Figure 6 This is a schematic diagram of a dynamic simulation method for coupled disasters of coal mine fire and gas explosion according to an embodiment of the present invention.

[0056] In the diagram, 1. Primary explosion chamber; 2. Explosion propagation tunnel; 3. Secondary explosion chamber; 4. Gas supply cylinder group; 5. Sealed bottle cap; 6. Inlet valve; 7. Concentration regulator; 8. Gas delivery pipe; 9. Mixing cylinder; 10. Data signal processor; 11. Intelligent visual platform; 12. Monitoring camera probe; 13. Variable frequency fan; 14. Distributed multi-hole air supply pipeline; 15. Observation window; 16. Observation window; 17. Observation window; 18. Gas intake pipeline; 19. Temperature controller; 20. Infrared radiation heating device; 21. Gas sensor; 22. Temperature sensor installed in the secondary explosion chamber; 23. Pressure sensor installed in the secondary explosion chamber; 24. Temperature sensor installed in the primary explosion chamber. 25. Pressure sensor installed in the primary explosion chamber; 26. Ignition rod; 27. Ignition electrode; 28. Pressure relief valve; 29. ​​Rubber ball; 30. Gas chromatograph; 31. Waste gas treatment device; 32. Ignition device; 33. Measuring point. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] A schematic diagram of a dynamic simulation system for coupled disasters of coal mine fire and gas explosion according to an embodiment of the present invention is shown below. Figure 1 As shown, it includes: an explosion chamber, a gas loading system, a dynamic air leakage control system, a thermal energy activation system, a sensor monitoring system, a pressure relief and gas disposal system, and an intelligent monitoring system;

[0059] In this embodiment of the invention, the overall structure of the explosion cavity is made of stainless steel, which can withstand high temperatures and prevent heat loss. Simultaneously, an explosion-proof concrete structure is used to confine the blast shock wave and debris within a controllable range; specifically, as shown... Figure 2 As shown, the explosion chamber consists of three modules: a primary explosion chamber 1, an explosion propagation tunnel 2, and a secondary explosion chamber 3. The primary explosion chamber 1 is designed as a cuboid structure with dimensions of 50 cm × 50 cm × 60 cm. The explosion propagation tunnel 2 connects the primary explosion chamber 1 and the secondary explosion chamber 3, and its height can be designed to be 20 cm and its length to be 30 cm. The secondary explosion chamber 3 is designed as a semi-arch shape with a height of 40 cm.

[0060] In one specific embodiment of the present invention, when the primary explosion chamber 1 simulates the collapse zone and fracture zone inside a goaf, a multi-layer filling structure is adopted. Specifically, the multi-layer filling structure adopts a three-layer filling method in the vertical direction. The bottom layer is a distributed porous air supply pipeline 14 for uniformly releasing gas and airflow into the chamber. Above the distributed porous air supply pipeline, a collapse zone filling layer is set, which is filled with crushed stone and coal gangue. During filling, it is necessary to ensure that the porosity reaches between 40% and 50% to simulate the collapse zone of the goaf. Above the collapse zone filling layer, a fracture zone filling layer is set, which is filled with gypsum board with a spacing of about 3-5 cm between the gypsum boards. After the collapse zone and fracture zone are filled, coal powder is arranged in the chamber. A gas loading system is connected to the left side of the bottom of the chamber, and a fan is arranged on the right side.

[0061] The gas loading system is connected to the primary explosion chamber 1 via a gas delivery pipe 8. It includes a gas supply cylinder group 4, an inlet valve 6, a gas delivery pipe 8, a sealing cap 5, a concentration regulator 7, and a mixing cylinder 9. In this embodiment of the invention, in order to simulate the environment of the goaf and the coal mining face and provide the required gas, it is necessary to precisely control the concentration of experimental gases in the system, such as CH4, oxygen, and CO2. Therefore, the gas supply cylinder group 4 contains multiple independent gas cylinders to hold the corresponding experimental gases. When injecting experimental gases into the primary explosion chamber 1, the sealing cap 5 and the inlet valve 6 need to be opened first, and the concentration of experimental gases required for the simulation is adjusted by the concentration regulator 7. Then, the experimental gases are released and enter the primary explosion chamber 1 through the gas delivery pipe 8 and the mixing cylinder 9.

[0062] The dynamic air leakage control system is connected to the primary explosion chamber 1 through a distributed multi-hole air supply duct 14. It includes a variable frequency fan 13, an air leakage valve, and a flow meter. The flow meter is a high-precision flow meter. Through the combination of the high-precision flow meter and the variable frequency fan 13, the air leakage rate can be precisely adjusted between 0.1-1m / s. By controlling the air leakage valve, the variable frequency fan 13 can output different air leakage rates.

[0063] In one specific embodiment of the present invention, in order to more accurately simulate the complex air leakage path in the goaf and improve the accuracy and repeatability of the simulation experiment, a fuzzy control algorithm is introduced into the system. First, the initial air leakage rate required for the simulation experiment is set through the intelligent monitoring system. After the dynamic control air leakage system is started, the real-time air leakage rate in the distributed multi-hole air supply pipeline 14 is collected in real time by a high-precision flow meter and transmitted to the intelligent monitoring system. The intelligent monitoring system has a built-in fuzzy adaptive control algorithm (PID) to control the speed of the variable frequency fan 13 to adjust the air leakage rate in real time, thereby simulating the complex air leakage path changes of the underground ventilation disorder and completing the simulation of dynamic working conditions.

[0064] The thermal energy activation system is installed inside the primary explosion chamber 1, including a high-temperature loading device and an ignition device, which are used to provide a heat source and an ignition source for the coal sample inside the primary explosion chamber.

[0065] In this embodiment of the invention, the high-temperature loading device includes a temperature controller 19 and an infrared radiation heating device 20. The infrared radiation heating device 20 provides a heat source to the primary explosion cavity to simulate the temperature gradient of the goaf. The temperature controller 19 regulates the heating temperature of the infrared radiation heating device. To provide the required high temperature for simulating the high-temperature induced gas explosion process of spontaneous combustion of coal in the goaf, the ignition device further includes an ignition electrode 27 and an ignition device 32. The ignition electrode 27 is triggered by an ignition rod 26. Figure 5 The diagram shown is a schematic diagram of an ignition electrode structure according to an embodiment of the present invention. The ignition electrode is buried below the fissure zone. When the concentration of the experimental gas in the primary explosion chamber 1 reaches the set value, the ignition device 32 is remotely controlled to activate the ignition rod 26 to trigger the ignition electrode 27 for ignition, thereby triggering a simulated high-temperature explosion disaster.

[0066] The sensor monitoring system is deployed in the primary explosion chamber 1 and the secondary explosion chamber 3, and includes a gas sampling pipeline 18; a temperature sensor 24 installed in the primary explosion chamber and a temperature sensor 22 installed in the secondary explosion chamber; a pressure sensor 25 installed in the primary explosion chamber and a pressure sensor 23 installed in the secondary explosion chamber; and a gas sensor 21 installed in the secondary explosion chamber 3, which is used to collect physical parameters and gas sample data of the primary and secondary explosion chambers in real time during the experiment.

[0067] In this embodiment of the invention, during the filling of the sequentially exploding cavity 1, measuring points 33 and gas sampling pipes 18 are arranged in the coal powder fissures of the cavity, such as... Figure 3 As shown, ten measuring points 33 are arranged in three layers: upper, middle and lower. The physical parameters and gas sample data during the experiment include parameters such as temperature, pressure and gas concentration.

[0068] The pressure relief and gas disposal system includes a pressure relief valve 28, a rubber ball 29, a gas chromatograph 30, and a waste gas treatment device 31. The pressure relief valve 28 is located on the side wall of the explosion propagation tunnel 2 and can be manually opened to relieve pressure inside the system. The rubber ball 29, located at the outlet of the pressure relief valve 28, is used to collect the experimental gas generated after the explosion simulation. The gas chromatograph 30 further analyzes the experimental gas to obtain the reaction of the gas explosion gas. Finally, all waste gas is transferred to the waste gas treatment device 31 to achieve the purification and sealing of the waste gas or residual gas after the experiment, so as not to cause environmental pollution.

[0069] The intelligent monitoring system is used to collect and analyze the data gathered by various systems during the simulation experiment.

[0070] In this embodiment of the invention, the intelligent monitoring system includes an observation window and a monitoring camera probe, such as... Figure 4 As shown, the observation windows include observation window 15 set in the primary explosion cavity, observation window 16 set in the explosion propagation tunnel, and observation window 17 set in the secondary explosion cavity. The monitoring camera probe is a high-definition explosion-proof real-time monitoring camera probe 12. By sequentially configuring the high-definition explosion-proof real-time monitoring camera probe 12 in each observation window, the propagation explosion image of the explosion flame is captured and recorded.

[0071] In one specific embodiment of the present invention, the intelligent monitoring system is further configured with a data signal processor 10 and an intelligent visual platform 11. The data signal processor 10 preprocesses the collected data to extract key parameters from the physical parameters and gas sample data during the system experiment, such as temperature peak, pressure peak, and gas concentration changes, and transmits them to the intelligent visual platform 11 for data analysis, plotting temperature-time curves, gas concentration-explosion pressure relationship diagrams, and calculating flame propagation rate, etc.

[0072] In another specific embodiment of the present invention, the operation flow of the system of the present invention is as follows:

[0073] First, an explosion chamber is filled. Distributed porous air supply pipes are laid at the bottom of the chamber, and the middle collapse zone is filled with crushed stone and coal gangue to ensure a porosity of 40% to 50% to simulate the collapse zone of a goaf. The upper fracture zone is covered with gypsum board with a spacing of about 3-5 cm. After the collapse zone and fracture zone are filled, coal powder is placed in the chamber. In addition, gas sampling pipes are pre-installed in the chamber to facilitate the collection of gas concentration data during subsequent experiments.

[0074] Then, the airtightness of the device is tested. The gas loading system, dynamic air leakage control system, thermal energy excitation system, sensor monitoring system, pressure relief and gas disposal system, and intelligent monitoring system are connected to the cavity of the simulated goaf. Power is supplied to each system device to check whether there are any problems with the device and whether it can work normally. The airtightness of the entire system device is tested to ensure that its leakage rate is ≤0.1% / h.

[0075] Then, coal powder filling and vacuum treatment are carried out: coal powder is filled into the primary explosion chamber and ignition electrodes are embedded, and then the entire explosion chamber is evacuated.

[0076] Further initial parameter settings were performed: before the simulation experiment began, the laboratory temperature was maintained at 20±5℃, and the initial internal temperature of the cavity was set at 20±5℃; the variable frequency fan in the dynamic control air leakage system was turned on, and air was injected through the multi-distributed multi-hole air supply pipeline to ensure that the oxygen concentration was maintained between 19% and 21%, the flow rate was controlled at about 0.50L / min, and the initial air leakage velocity was set at 0.3m / s; the valve of the gas supply cylinder group in the gas loading system was opened, and the initial gas concentration of 5% and the oxygen concentration of 12% were introduced into the cavity through the concentration regulator, and the initial coal powder temperature was 25℃;

[0077] Further into the low-temperature oxidation stage: The thermal energy activation device is turned on, and low-temperature oxidation is initiated to raise the temperature inside the primary explosion chamber to 60°C. By dynamically controlling the air leakage system, the air velocity is controlled at 0.3 m / s during the stable oxygen diffusion stage, which is changed by altering the air leakage rate from 0 to 3 hours; the air velocity is gradually increased to 0.5 m / s from 3 to 5 hours; and further increased to 0.7 m / s from 5 to 8 hours. From 8 to 12 hours, the air velocity is suddenly reduced to 0.2 m / s. This is to simulate the critical operation of a coal mine ventilation system failure or localized leak, artificially creating an explosion critical state of "low air velocity - high concentration - thermoelectric coupling". At the same time, the multi-parameter monitoring system is turned on, and the temperature acquisition frequency is set to 1 time / min to continuously monitor the temperature changes at various measuring points in the goaf of the experimental chamber. Gas samples are taken from the measuring points every 30 minutes, and the gas composition and concentration are analyzed using a gas chromatograph. The data is transmitted to the intelligent monitoring system. When the oxygen concentration drops to 12% and the carbon monoxide concentration exceeds 100 ppm, the coal is determined to have entered the accelerated oxidation stage.

[0078] Simulated coal spontaneous combustion induced by high temperature primary gas explosion: The methane concentration inside the cavity is monitored by a sensor monitoring system, and methane is injected into the cavity through a gas loading system to simulate the gas inrush in the goaf. At the same time, the oxygen concentration is maintained at ≤12%, and the fan is accelerated to promote uniform gas diffusion and prevent excessively high local concentrations. During this process, the ratio of methane to oxygen must be monitored in real time to ensure that the gas is in the explosion triangle zone. Simultaneously, the high temperature loading system is turned on. When the temperature reaches about 300℃, the oxygen concentration is changed to pure oxygen 21%, and infrared auxiliary heating is used to raise the temperature. When the coal temperature is greater than 537℃, the process of coal spontaneous combustion induced by primary gas explosion is observed by controlling and changing the gas concentration. If the high temperature point of coal spontaneous combustion does not induce a gas explosion, a backup remote ignition system can be activated to induce a primary gas explosion.

[0079] Recording an explosion process: High-definition explosion-proof real-time monitoring camera probes capture the flame propagation path during the explosion, pressure sensors in the sensor monitoring system record the explosion overpressure peak and decay path, and gas chromatographs monitor gaseous products such as carbon dioxide after the explosion and transmit the data to the intelligent monitoring system.

[0080] Secondary explosion determination: Open the temperature sensor and gas concentration sensor in the secondary explosion cavity to determine whether the concentration of suspended coal dust inside the cavity is >50 g / m³ and whether the ambient temperature is >700℃. If so, there is a risk of coal dust explosion. In addition, monitor whether the unburned gas from the first explosion has mixed into the adjacent secondary explosion cavity and whether the air concentration has reached the range of 5%-15%. If the ignition source left over from the first explosion enters the secondary explosion cavity at this time, it can also be determined that a secondary gas explosion has occurred. In summary, when a certain area meets the conditions of concentration within the explosion range and temperature above the ignition threshold, it can be determined that flame propagation has occurred and may even trigger a secondary explosion.

[0081] Intelligent monitoring data processing: The pressure relief device is opened, and gas components are collected through a connected rubber ball. All data is transmitted in real time to an independent server. A data signal processor then transmits the data to an intelligent monitoring platform for analysis. Key parameters from the multi-parameter monitoring system are extracted, and temperature-time curves are plotted. This includes extracting temperature data from high-temperature points in the coal spontaneous combustion reaction zone, plotting the temperature change over time at that point, and identifying the stages and critical temperatures of coal spontaneous combustion. A gas concentration-explosion pressure relationship diagram is plotted, correlating the peak explosion overpressure values ​​obtained from experiments at different gas concentrations, plotting scatter plots or curves, and fitting the relationship equation. Flame propagation rate and other parameters are calculated and optimized. The flame propagation process is recorded using a high-speed camera, and image processing technology is used to extract the flame front position, calculate the instantaneous and average flame velocity along the explosion propagation path, and continuously optimize the parameters.

[0082] Finally, depressurization and waste gas treatment were carried out: After the experiment, the entire experimental simulation device was shut down, and nitrogen gas was injected into the experimental chamber at a flow rate of 100 m3 / h for 0.05 h to cool the model chamber in an inert gas environment. After the residual gas was purified, the gas recovery pipeline and waste gas collection device were opened to remove and treat the adsorbed waste materials. The explosion debris was sealed and treated in accordance with relevant standards, and finally the experimental chamber was cleaned.

[0083] In another specific embodiment of the present invention, the present invention also provides a dynamic simulation method for coupled disasters of coal mine fire and gas explosion, the flowchart of which is shown below. Figure 6 As shown, the method includes:

[0084] An explosion cavity is constructed to simulate the collapse zone and fracture zone of a goaf; the explosion cavity includes a primary explosion cavity and a secondary explosion cavity connected by an explosion propagation roadway;

[0085] Inject a set concentration of experimental gas into the primary explosion chamber and provide a set rate of air leakage;

[0086] The coal sample inside the primary explosion chamber is heated to obtain real-time physical parameters and gas sample data in the primary explosion chamber;

[0087] When the physical parameters and gas sample data in the primary explosion chamber meet the set conditions for a primary explosion, a gas explosion is triggered inside the primary explosion chamber.

[0088] After a gas explosion is triggered inside the primary explosion chamber, real-time physical parameters and gas sample data in the secondary explosion chamber are obtained.

[0089] Based on the real-time physical parameters and gas sample data inside the secondary explosion cavity, determine whether the conditions for a secondary explosion are met.

[0090] Based on real-time physical parameters and gas sample data collected from the primary and secondary explosion chambers, quantitative relationship maps and dynamic parameters are generated to characterize the evolution of the disaster.

[0091] In one specific embodiment of the present invention, when injecting an experimental gas of a set concentration into the primary explosion cavity and providing a set rate of air leakage, a real-time air leakage efficiency is introduced to more scientifically characterize the characteristics of the airflow in the simulated goaf environment. This parameter is calculated by combining the structural characteristics of the primary explosion cavity, the flame propagation tunnel, and the secondary explosion cavity, as well as the real-time air leakage efficiency. Defined as the actual measured flow rate With theoretical flow The ratio is calculated using the following formula:

[0092] ;

[0093] Among them, the actual measured flow rate The theoretical flow rate is obtained through real-time measurement using a high-precision flow meter. This refers to calibrating the entire cavity using a flow calibration device without filling it with coal samples before conducting a simulation experiment. Different fan speeds correspond to different pressure differences; the stable flow rate under these conditions is recorded, and a "pressure difference-flow rate curve" of the system is plotted. The theoretical flow rate under the current conditions is then calculated based on the curve and the real-time monitored pressure difference. Then, calculate the real-time air leakage efficiency according to the above formula.

[0094] Meanwhile, to more accurately simulate the complex air leakage paths in the goaf and improve the accuracy and repeatability of the simulation experiment, this embodiment of the invention introduces a fuzzy control algorithm into the system. Specifically, the initial air leakage rate required for the experiment is set through an intelligent monitoring system, and the initial parameter value is set to... (Unit: m / s); After the dynamic air leakage control system is started, the actual air leakage rate in the pipeline is collected in real time by a high-precision flow meter, which is the actual measured flow rate. The data is transmitted in real time to the intelligent monitoring platform, thus establishing a closed-loop control circuit. A fuzzy adaptive PID control algorithm is built into the intelligent monitoring system to calculate the deviation. and rate of change Then, after fuzzification, fuzzy rule base and inference, and defuzzification, the final PID control output is obtained. The wind speed curve, such as step, ramp, and sine waveform, is loaded by the intelligent monitoring system through preset or automatic loading. Based on the above steps, the system adjusts the fan speed in real time to ensure high precision and high response speed in tracking the target curve, so as to simulate the complex air leakage path changes of the underground ventilation disorder and complete the simulation of dynamic working conditions.

[0095] In this embodiment of the invention, when the system is in the early low-temperature oxidation stage of coal spontaneous combustion, i.e., when the risk of gas accumulation is low, the simulation experiment is ensured to proceed normally according to the preset air leakage rate. At this time, the PID controller in the intelligent monitoring system tracks the initially set... Curve, when When slow changes occur, the system will slightly adjust the fan power to maintain the actual measured flow rate. The system maintains a stable operating state. When the system is in the gas accumulation stage, i.e., the risk of explosion increases, it will actively intervene to prevent the gas explosion from spiraling out of control. Simultaneously, it will collect current critical state data. If efficiency decreases, the system will automatically increase the target leakage rate to restore ventilation efficiency; if the gas concentration rises above 9%, the system will automatically decrease the target leakage rate to slow down the gas accumulation rate. Thus, the flow rate is precisely controlled by real-time monitoring through a high-precision flow meter.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dynamic simulation system for coupling disasters of coal mine fire and gas explosion, characterized in that, include: Explosion chamber, gas loading system, dynamic control air leakage system, thermal energy activation system, sensor monitoring system, pressure relief and gas disposal system, intelligent monitoring system; The explosion cavity includes a primary explosion cavity and a secondary explosion cavity connected by an explosion propagation channel; The gas loading system is connected to the primary explosion chamber via a gas delivery pipe and includes a gas supply cylinder group, an inlet valve, a gas delivery pipe, a sealing cap, a concentration regulator, and a gas mixing cylinder, used to supply and maintain a set concentration of experimental gas to the primary explosion chamber. The dynamic air leakage control system is connected to the primary explosion cavity through a distributed porous air supply pipeline, and includes a variable frequency fan, an air leakage valve and a flow meter, for providing air leakage with a controllable flow rate to the primary explosion cavity; The thermal energy activation system is installed inside the primary explosion cavity and includes a high-temperature loading device and an ignition device, used to provide a heat source and an ignition source for the coal sample inside the primary explosion cavity. The sensor monitoring system, deployed in the primary explosion chamber and the secondary explosion chamber, includes a gas sampling pipeline, a temperature sensor, a pressure sensor, and a gas sensor, and is used to collect physical parameters and gas sample data of the primary explosion chamber and the secondary explosion chamber in real time during the experiment. The pressure relief and gas disposal system includes a pressure relief valve, a rubber ball, a gas chromatograph, and a waste gas treatment device, which is used for safe pressure relief and waste gas treatment after the simulation experiment. The intelligent monitoring system is used to collect and analyze the data gathered by various systems during the simulation experiment.

2. The dynamic simulation system for coupled disasters of coal mine fire and gas explosion according to claim 1, characterized in that: The cavity of the primary explosion employs a multi-layered filling structure, which includes: The distributed porous air supply pipeline laid at the bottom of the primary explosion cavity; A caving zone filling layer is provided above the distributed porous air supply duct, which is filled with crushed stone and coal gangue; A crack filling layer is provided above the collapse zone filling layer, and is filled with gypsum board.

3. The dynamic simulation system for coupled disasters of coal mine fire and gas explosion according to claim 1, characterized in that: The dynamic air leakage control system includes: The distributed multi-hole air supply duct adopts an equally spaced pore structure to control the leakage valve so that the variable frequency fan outputs different leakage rates; A flow meter is used to monitor the flow rate in leaky ductwork in real time.

4. The dynamic simulation system for coupled disasters of coal mine fire and gas explosion according to claim 1, characterized in that: The thermal energy excitation system includes: A high-temperature loading device, comprising a temperature controller and an infrared radiation heating device; The infrared radiation heating device is used to provide a heat source for the cavity inside the primary explosion. The temperature controller is used to regulate the heating temperature of the infrared radiation heating device; An ignition device, including an ignition electrode and an ignition device, is used to remotely control the ignition device to trigger the ignition electrode to ignite when the concentration of the experimental gas in the primary explosion chamber reaches a set value.

5. The dynamic simulation system for coupled disasters of coal mine fire and gas explosion according to claim 1, characterized in that: In the sensor monitoring system, a gas extraction pipeline is laid in the coal powder fissures of the primary explosion chamber to extract gas from the primary explosion chamber.

6. The dynamic simulation system for coupled disasters of coal mine fire and gas explosion according to claim 1, characterized in that: The pressure relief and gas handling system includes: A rubber ball installed at the outlet of the pressure relief valve is used to collect the reaction gases after the explosion. A gas chromatograph is connected to the gas sampling line for concentration analysis of the gas extracted in the gas sampling line. Waste gas treatment device, used to adsorb and purify residual waste gas.

7. The dynamic simulation system for coupled disasters of coal mine fire and gas explosion according to claim 1, characterized in that: The intelligent monitoring system includes: Observation windows are respectively set up outside the primary explosion cavity, outside the explosion propagation tunnel, and outside the secondary explosion cavity, and monitoring camera probes are placed in the observation windows; The data signal processor is communicatively connected to the sensor monitoring system and is used to process the data collected by the sensor monitoring system and send it to the intelligent visual platform.

8. A dynamic simulation method for coupled disasters of coal mine fire and gas explosion, employing a dynamic simulation system for coupled disasters of coal mine fire and gas explosion as described in any one of claims 1-7, characterized in that, include: An explosion cavity is constructed to simulate the collapse zone and fracture zone of a goaf; the explosion cavity includes a primary explosion cavity and a secondary explosion cavity connected by an explosion propagation roadway; Inject a set concentration of experimental gas into the primary explosion chamber and provide a set rate of air leakage; The coal sample inside the primary explosion chamber is heated to obtain real-time physical parameters and gas sample data in the primary explosion chamber; When the physical parameters and gas sample data in the primary explosion chamber meet the set conditions for a primary explosion, a gas explosion is triggered inside the primary explosion chamber. After a gas explosion is triggered inside the primary explosion chamber, real-time physical parameters and gas sample data in the secondary explosion chamber are obtained. Based on the real-time physical parameters and gas sample data inside the secondary explosion cavity, determine whether the conditions for a secondary explosion are met. Based on real-time physical parameters and gas sample data collected from the primary and secondary explosion chambers, quantitative relationship maps and dynamic parameters are generated to characterize the evolution of the disaster.

9. The dynamic simulation method for coupled disasters of coal mine fire and gas explosion according to claim 8, characterized in that: To determine whether the conditions for a secondary explosion are met, the following are included: Obtain the ambient temperature inside the secondary explosion cavity and determine whether the ambient temperature is higher than 700℃; Obtain gas concentration data within the secondary explosion cavity to determine whether the gas concentration is within the 5%-15% range; Obtain the coal dust concentration inside the secondary explosion cavity and determine whether the coal dust concentration is greater than 50 g / m³; When all of the above conditions are met, it is determined that the internal conditions for a secondary explosion are met.

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