A coal spontaneous combustion-inhibition-reignition whole-process dynamic simulation experiment system and method

Abstract

This invention discloses a dynamic simulation experimental system and method for the entire process of coal spontaneous combustion-inhibition-reignition, belonging to the field of coal mine fire prevention technology. The system integrates four modules: programmed temperature control and reaction chamber, multi-channel gas distribution and supply, inhibition medium supply, and temperature monitoring and online gas analysis. It can effectively simulate the air leakage environment under different oxygen concentration conditions in goaf areas and supports the individual or combined application of inert gas injection and liquid inhibitor atomized spraying. By monitoring the changes in temperature and gas indicators during the reaction process in real time, the entire process of coal spontaneous combustion, inhibition and cooling, and re-ignition can be reproduced. Based on the full-process data, characteristic temperature indicators and gas generation rates are extracted to establish inhibition effectiveness evaluation indicators, enabling quantitative evaluation of the coal spontaneous combustion inhibition effect under different inhibition media. This invention is applicable to the study of coal spontaneous combustion and re-ignition mechanisms and the performance evaluation of inhibition materials, providing a reliable experimental means for the screening and process optimization of coal mine fire prevention and extinguishing materials.

Description

Technical Field

[0001] This invention relates to the field of coal mine safety and fire prevention technology, specifically to a dynamic simulation experimental system and method for the entire process of coal spontaneous combustion-inhibition-reignition, applicable to simulating the entire process of coal from initial oxidation, inhibition treatment to re-ignition. Background Technology

[0002] Coal exposed to air for extended periods during production, storage, and in underground goaf areas is prone to low-temperature oxidation, leading to heat accumulation and spontaneous combustion. Even after initial fire suppression, residual coal still poses a high risk of reignition under specific conditions (such as restored oxygen supply and heat accumulation), resulting not only in resource loss but also the potential for secondary gas explosions or the generation of large amounts of toxic and harmful gases, seriously threatening mine safety. Therefore, in-depth research into the reignition mechanisms following spontaneous combustion and inhibition, and a scientific assessment of the long-term effectiveness of various fire prevention and extinguishing measures (such as injecting inert gases and spraying inhibitors), are crucial for developing precise fire prevention and control strategies.

[0003] Currently, experimental research devices and methods for coal spontaneous combustion mainly focus on identifying the spontaneous combustion tendency of coal or analyzing oxidation characteristics under single isothermal / programmed temperature conditions. These traditional methods have significant limitations and cannot meet the research needs of the complex and dynamic entire process of "spontaneous combustion-inhibition-reignition," mainly in the following aspects: (1) Insufficient environmental simulation capability: Existing devices are unable to accurately reproduce the complex alternating environment of "oxygen deficiency cooling-heat accumulation-re-oxidation" that may exist on site after fire extinguishing. The dynamic control accuracy of the multi-component gas components (such as different oxygen concentrations) and temperature history in the goaf is insufficient, resulting in deviations between experimental conditions and real disaster conditions.

[0004] (2) Limited process linkage and evaluation functions: Most devices have limited functions, focusing on the primary oxidation stage of coal, and lack experimental designs that link with suppression measures (such as inert gas injection and liquid inhibitor spraying). They cannot simulate the dynamic application process of the suppression medium under specific temperature or atmosphere conditions, and lack the ability to systematically monitor and quantitatively evaluate the behavior changes of coal after suppression under re-ignition conditions, making it difficult to use for rapid comparison and optimization of different suppression schemes.

[0005] In summary, current technologies lack a comprehensive experimental platform that integrates precise programmed temperature control, dynamic multi-atmosphere gas distribution, flexible application of inhibitory media, and simultaneous online monitoring of multiple parameters to fully simulate and scientifically evaluate the entire process of coal spontaneous combustion, inhibition, and re-ignition. Therefore, developing such a system and method has significant theoretical value and promising engineering applications. Summary of the Invention

[0006] Technical Problem: The purpose of this invention is to overcome the shortcomings of the prior art and provide a dynamic simulation experimental system and method for the entire process of coal spontaneous combustion-inhibition-reignition, so as to solve the problem that the prior art is unable to completely reproduce the entire process of coal spontaneous combustion-inhibition-reignition and to quantitatively evaluate the inhibition effect.

[0007] Technical solution: The present invention provides a dynamic simulation experimental system for the entire process of coal spontaneous combustion-inhibition-reignition, comprising a programmable temperature control and reaction chamber module, a multi-channel gas distribution and supply module, an inhibition medium supply module, and a temperature monitoring and online gas analysis module connected as an integrated unit; The programmed temperature control and reaction chamber module includes a programmed temperature rise device and a cylindrical high-temperature resistant stainless steel reaction chamber placed therein. The programmed temperature rise device includes a programmed temperature rise parameter setting interface, a second temperature sensor, a high-temperature resistant support platform, a cooling fan, and an insulation layer. The reaction chamber is placed on the high-temperature resistant support platform. The lower part of the reaction chamber is provided with a reaction chamber air inlet and a reaction chamber inert gas injection port. Above the reaction chamber air inlet and reaction chamber inert gas injection port is a lower perforated plate that carries the coal sample. On the left side wall above the lower perforated plate is a reaction chamber inhibitor application port, and on the right side wall is a reaction chamber temperature sensor interface. A stainless steel atomizing nozzle that sprays liquid inhibitor droplets onto the coal sample is connected to the reaction chamber inhibitor application port. A temperature sensor is provided in the reaction chamber temperature sensor interface. Above the stainless steel atomizing nozzle is an upper perforated plate that covers the coal sample. On the reaction chamber wall above the upper perforated plate is a reaction chamber air outlet, and a sealing flange is provided at the top. The multi-channel gas distribution and supply module includes a dynamic gas distributor with a dynamic gas distributor parameter setting interface. One side of the dynamic gas distributor is connected to the pipelines of the air tank, carbon dioxide tank 1 and nitrogen tank 1 respectively, and the other side is provided with an oxygen-containing mixed gas outlet pipe connected to the air inlet of the reaction chamber. A mass flow meter is provided on the oxygen-containing mixed gas outlet pipe. The inhibition medium supply module includes an inhibitor application unit and an inert gas injection unit. The inhibitor application unit includes a constant flow injection pump for injecting inhibitor and a storage tank containing inhibitor solution. The inert gas injection unit includes a carbon dioxide tank and a nitrogen tank for injecting inert gas into the reaction chamber to establish an inert environment and to cool the coal sample. The carbon dioxide tank and nitrogen tank provide pure carbon dioxide and pure nitrogen, which are collected by pipelines and connected to the inert gas injection port pipeline of the reaction chamber via a control valve and a mass flow meter to control the mixing ratio and total gas flow. The constant flow injection pump includes a syringe and a flow path switching valve on the syringe. The left side of the flow path switching valve is connected to the inhibitor application port of the reaction chamber via an inhibitor liquid outlet pipe, and the right side is inserted into the storage tank containing inhibitor solution via a corrosion-resistant injection pipe. The inhibitor solution in the storage tank is delivered to the reaction chamber at a constant flow rate and atomized by a stainless steel atomizing nozzle before being evenly sprayed onto the surface of the coal sample. The temperature monitoring and online gas analysis module includes a paperless recorder, a gas chromatograph, a data acquisition and processing terminal, a dry air generator, a hydrogen generator, and a nitrogen tank. The paperless recorder has a temperature sensor signal output terminal one connected to the reaction chamber temperature sensor interface pipeline and a temperature sensor signal output terminal two connected to the temperature sensor two pipeline, used to collect and record the center temperature of the coal sample and the ambient temperature of the reaction chamber in real time. The gas chromatograph includes a chromatographic column inside the chamber and a detector at the bottom of the chamber. The top of the chamber has a sample inlet pipe connected to the reaction chamber outlet, used for continuous online monitoring and analysis of the concentration of multiple components in the exhaust gas. The concentration of these multiple components should include at least the concentrations of oxygen, carbon monoxide, carbon dioxide, methane, ethane, ethylene, and acetylene. The sides of the chamber are connected to the dry air generator, hydrogen generator, and nitrogen tank via pipelines to achieve synchronous real-time monitoring of temperature and gas components.

[0008] The programmed temperature rise device includes a programmed temperature rise parameter setting interface, a power switch, a high-temperature resistant support platform, a cooling fan, and an insulation layer. The high-temperature resistant support platform is located inside the programmed temperature rise device and is used to place the reaction chamber. The cooling fan is installed on the top of the programmed temperature rise device and is used to force-cool the reaction chamber after the experiment. The insulation layer covers the inner or outer wall of the programmed temperature rise device to reduce heat loss and improve temperature control stability. The programmed temperature rise device can achieve multi-level gradient heating and constant temperature control within the range of 30~400℃, with a heating rate of 0.4~40℃ / min and an adjustment accuracy of 0.1℃ / min, to meet the simulation requirements of the entire process of coal spontaneous combustion-inhibition-reignition under different heating rates. The model of the programmed temperature rise device is SP-6801A.

[0009] The reaction chamber is a high-temperature resistant stainless steel cylindrical structure. The inner wall of the cylinder is polished to reduce gas flow resistance and prevent coal sample particles from adhering. The bottom of the reaction chamber is equipped with a lower perforated plate and the top is equipped with an upper perforated plate. Both the upper and lower perforated plates are stainless steel plates with a number of through holes evenly distributed on them. The lower perforated plate is used to support the coal sample, and the upper perforated plate is used to prevent the coal sample from being blown out by the airflow and causing gas path blockage. The upper and lower perforated plates work together to achieve uniform distribution of gas entering the reaction chamber.

[0010] The first temperature sensor is an armored thermocouple, whose measuring end is inserted into the geometric center of the coal sample through the temperature sensor interface of the reaction chamber, for real-time acquisition and recording of the coal sample center temperature; the second temperature sensor is an armored thermocouple, whose measuring end is located inside the programmed heating device and outside the reaction chamber, for real-time acquisition and recording of the reaction chamber ambient temperature; through the synchronous monitoring of the first and second temperature sensors, the coal sample center temperature and the reaction chamber ambient temperature are obtained in real time, for calculating the crossover point temperature and judging the coal spontaneous combustion process.

[0011] The volume ratio of pure carbon dioxide and pure nitrogen provided by the second carbon dioxide gas tank and the second nitrogen gas tank is 1:9 to 9:1; the spray dosage control accuracy of the constant flow injection pump is ≤±0.1ml, the output rate of the constant flow injection pump is 0.5~5ml / min, and the total output is 5~50ml, so as to achieve inhibition treatment with different application intensities and application durations.

[0012] The above-described dynamic simulation experimental method for the entire process of coal spontaneous combustion-inhibition-reignition includes the following steps: S1. Coal sample preparation and pretreatment: Fresh coal samples collected from underground are crushed and sieved under an inert atmosphere to obtain experimental coal samples within a preset particle size range. S2. Coal Sample Oxidation Heating Stage: The prepared coal sample is loaded into the reaction chamber, ensuring the chamber is well sealed. The dynamic gas mixer and mass flow meter in the multi-channel gas distribution and supply module are controlled to continuously supply the reaction chamber with a preset oxygen-containing mixed gas of a predetermined composition and flow rate, according to the experimentally preset oxygen-containing mixed gas composition and flow rate requirements. The oxygen-containing mixed gas is a mixture of air, carbon dioxide, and nitrogen. Simultaneously, the programmed heating device is activated. Through the programmed heating parameter setting interface, the programmed heating device is controlled to heat the room temperature to the preset oxidation characteristic temperature T1 at a heating rate of 0.5~5℃ / min. The oxidation characteristic temperature T1 is a set value within the range of 50~400℃, and the temperature is held at the oxidation characteristic temperature T1 for a set time of 0~12h to simulate the heating and isothermal oxidation process of the coal sample at different oxidation stages. S3, Inhibition and Cooling Stage: After the coal sample temperature reaches the oxidation characteristic temperature T1 and is kept at a constant temperature, the programmed heating device is turned off to stop heating, and the dynamic gas mixing instrument is controlled to stop the introduction of oxygen-containing mixed gas. Then, the control valve in the inhibition medium supply module is controlled to introduce inert gas supplied by carbon dioxide tank 2 and nitrogen tank 2 in the inert gas injection unit into the reaction chamber. At the same time, the constant flow injection pump in the inhibition medium supply module is started to deliver the pre-prepared inhibitor solution in the storage tank to the stainless steel atomizing nozzle through the flow path switching valve to dynamically spray the coal sample surface, thereby achieving chemical inhibition treatment of the coal sample. Under the synergistic effect of inert gas cooling and inhibitor solution spraying, the coal sample temperature is reduced to room temperature or the preset re-ignition initiation temperature T2, completing the inhibition and cooling stage. S4. Coal Sample Reignition Stage: After the coal sample cools to the preset reignition initiation temperature T2, turn off the constant flow injection pump in the inhibition medium supply module, stop the inhibitor spraying, and close the control valve to stop the inert gas from being introduced into the reaction chamber. At the same time, control the dynamic gas mixer and mass flow meter in the multi-channel gas distribution and supply module to reintroduce the oxygen-containing mixed gas with preset components and flow rate into the reaction chamber. Subsequently, start the programmed heating device to perform a secondary programmed heating of the coal sample, heating it from the reignition initiation temperature T2 to the preset termination temperature at a heating rate of 0.5~5℃ / min. Monitor the changes in the coal sample center temperature, the composition and concentration of the gas discharged from the reaction chamber outlet in real time until the coal sample reignites or reaches the preset experimental termination temperature, and end the experiment. S5. Synchronous Monitoring of Data Throughout the Entire Experiment: During the entire experiment from steps S2 to S4, the experimental parameters are synchronously monitored and recorded throughout the entire process via the data acquisition and monitoring module; specifically including: Temperature monitoring: The paperless recorder continuously monitors and records the temperature change data of the coal sample center and reaction chamber, and generates time-temperature change curves in real time; Gas concentration monitoring: The gas discharged from the gas outlet of the reaction chamber and the gas entering through the sample inlet pipe are sampled and analyzed online by gas chromatograph, and the concentration change data of multiple components are recorded simultaneously. Data recording and storage: Record and store the temperature change data and multi-component gas concentration change data obtained from the above-mentioned experiment, for subsequent analysis and evaluation of coal spontaneous combustion tendency, inhibitor inhibition effect and re-ignition characteristics; S6. Inhibition Efficiency Analysis and Evaluation: Based on the temperature change data and multi-component gas concentration change data obtained in step S5, the behavior characteristics of the coal sample in step S2 during the oxidation and heating stage, the inhibition and cooling stage in step S3, and the coal sample re-ignition stage in step S4 are analyzed. Characteristic temperature parameters and gas release characteristic parameters are extracted from the analysis, and an inhibition efficiency evaluation index system is established. Based on this, the comprehensive inhibition effect of the inhibition medium supply module on the inhibitor or inert gas applied by the programmed temperature control and reaction chamber module is quantitatively evaluated, and the optimal inhibitor type, concentration ratio, and application process parameters suitable for the target coal sample are selected.

[0013] The reaction chamber is continuously supplied with an oxygen-containing mixed gas of preset components and flow rates. The oxygen-containing mixed gas is either a nitrogen-oxygen mixture with an oxygen volume concentration of 5%-21%, or a mixture of carbon dioxide and dry air. The oxygen volume concentration is precisely controlled by a dynamic gas mixing instrument to simulate the oxygen-containing environment under different air leakage intensities in the goaf of a mine. The total flow rate of the oxygen-containing mixed gas is controlled within the range of 50-500 ml / min. The total flow rate of the inert gas is controlled within the range of 50-500 ml / min. The output rate of the inhibitor solution is controlled within the range of 0.5-5 ml / min, and the total output is controlled within the range of 5-50 ml. The output rate and total output are independently controllable to achieve inhibition treatment with different application intensities and application durations. The inhibitor solution is uniformly sprayed onto the surface of the coal sample in an atomized form through a stainless steel atomizing nozzle, with a spray coverage area of ​​not less than 90% of the coal sample surface area.

[0014] The preset re-ignition initiation temperature T2 is lower than the oxidation characteristic temperature T1 in step S2, used to simulate the re-ignition behavior of coal samples that have not fully recovered to room temperature after inhibition cooling and are re-exposed to oxidative conditions; the heating rate of the secondary programmed heating of the coal sample is consistent with the heating rate of step S2, controlled within the range of 0.5~5℃ / min, to ensure the comparability of the oxidation heating stage and the re-ignition stage; the multi-component gas concentration change data includes the concentrations of O2, CO, CO2, CH4, C2H6, C2H4, and C2H2, wherein the detection accuracy of CO is ≤1 ppm and the detection accuracy of O2 is ≤0.1%; the sampling interval of the gas chromatograph (402) is 10~30 minutes / time, and the sampling interval is dynamically adjusted according to experimental needs.

[0015] The suppression effectiveness evaluation index system is established based on characteristic temperature parameters and gas release characteristic parameters, wherein: The characteristic temperature parameters include: oxidation characteristic temperature T1, re-ignition initiation temperature T2, crossover temperature, and the first detection temperature of the characteristic gas; the crossover temperature is the intersection point of the coal sample center temperature and the reaction chamber ambient temperature curve; the characteristic gases include CO, C2H4, and C2H2, and the first detection temperature is the corresponding temperature at which each characteristic gas is first detected by the gas chromatograph. The gas release characteristic parameters include: the oxygen consumption rate, CO generation rate, CO / CO2 ratio, and C2H6 / C2H4 ratio calculated based on the time-varying laws of O2, CO, CO2, CH4, C2H6, C2H4, and C2H2 gas concentrations obtained by gas chromatograph. The inhibition effectiveness evaluation index system consists of inhibition rate, cooling efficiency, reignition inhibition index, characteristic temperature offset, and gas release inhibition coefficient, wherein: The inhibition rate is used to characterize the degree to which the inhibitor or inert gas inhibits the oxidation reaction rate of the coal sample. The cooling efficiency is used to characterize the rate and magnitude of temperature decrease in the coal sample after the application of inhibitors or inert gases during the inhibition and cooling stages. The reignition inhibition index is used to characterize the ease with which a coal sample is re-oxidized during the reignition stage and the intensity of the reignition. The characteristic temperature offset is used to characterize the change in the characteristic temperature of the coal sample before and after the application of the inhibitor or inert gas, namely the change in the oxidation characteristic temperature T1, the re-ignition initiation temperature T2, the crossover temperature, and the first detection temperature of the characteristic gas. The gas release inhibition coefficient is used to characterize the degree of change in the amount and rate of generation of characteristic gases before and after the application of an inhibitor or inert gases including CO, C2H4, and C2H2; By comparing the changes in characteristic temperature parameters and gas release characteristic parameters before and after applying different inhibitor solutions and injecting inert gas, the comprehensive inhibition performance of the inhibitor solution and inert gas is comprehensively evaluated based on five indicators: inhibition rate, cooling efficiency, reignition inhibition index, characteristic temperature shift, and gas release inhibition coefficient. Among them, the higher the inhibition rate, the higher the cooling efficiency, the higher the reignition inhibition index, the larger the characteristic temperature shift, and the higher the gas release inhibition coefficient, the better the inhibition effect.

[0016] Beneficial effects: By adopting the above technical solution, this invention can be used to quantitatively evaluate the inhibitory effects of different inerting or inhibition measures on coal spontaneous combustion, providing reliable experimental basis for the optimization of on-site fire prevention and extinguishing processes and the determination of key parameters in coal mines; it effectively overcomes the shortcomings of existing technologies, providing strong technical support for the research and development of coal mine fire prevention and extinguishing materials, the optimization of process parameters, and the scientific assessment of fire risks. The main advantages compared to existing technologies are: 1) Achieved dynamic simulation of the entire process: Through modular integration, the entire process of coal sample from initial oxidation, inhibition and cooling to re-ignition was completely simulated in a single experimental system; through multi-channel gas distribution and supply modules, the complex alternation process of the field environment from oxygen-rich oxidation atmosphere to inert oxygen-deficient atmosphere, and then to re-ignition oxygen supply atmosphere was accurately simulated, which solved the technical limitations of existing experimental devices that are single in function and can only simulate static or single stages, restored the dynamic evolution process of "oxidation-inhibition-re-ignition", and significantly improved the engineering guidance value and practical reference significance of the experimental results.

[0017] 2) An innovative method for evaluating the suppression effect: The system integrates a flexibly configurable suppression medium supply module, supporting the individual or combined application of various suppression methods such as inert gas (including N2 and CO2) inerting and liquid inhibitor atomization spraying; through the coordinated control of the inert gas injection unit and the inhibitor application unit, researchers can study the intervention effect of the timing, method and dosage of suppression medium application on the coal spontaneous combustion process under controlled experimental conditions, which is particularly suitable for the rapid screening and comparative evaluation of new composite inhibitors and combined fire prevention and extinguishing schemes.

[0018] 3) Improved data monitoring synchronization and accuracy: The system achieves online synchronous monitoring of the temperature field (r) of the coal sample center and reaction chamber environment, as well as the evolution process of multi-component gaseous products including O2, CO, CO2, CH4, C2H6, C2H4, and C2H2. This monitoring scheme provides a comprehensive and reliable data foundation for deeply revealing the intrinsic mechanisms of coal spontaneous combustion and re-ignition, and for quantitatively analyzing the suppression effectiveness of different suppression measures such as inhibition rate, CO suppression coefficient, and characteristic temperature offset. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the coal spontaneous combustion-inhibition-reignition full-process simulation experimental system of the present invention.

[0020] Figure 2 This is a schematic diagram of the structure of the programmed temperature control and reaction chamber module of the present invention.

[0021] Figure 3 This is a schematic diagram of the reaction chamber structure and internal interfaces of the present invention.

[0022] Figure 4 This is a schematic diagram of the gas path connection and structure of the multi-gas path distribution and supply module of the present invention.

[0023] Figure 5 This is a schematic diagram showing the composition and connection of the suppression medium supply module of the present invention.

[0024] Figure 6 This is a schematic diagram showing the layout and connection of the temperature monitoring and online gas analysis module of the present invention.

[0025] Figure 7 This is a flowchart of the dynamic simulation experiment method for the entire process of "coal spontaneous combustion-inhibition-reignition" of the present invention.

[0026] In the diagram: 1-Programmed temperature control and reaction chamber module; 101-Programmed heating device; 102-Reaction chamber; 103-Sealing flange; 104-Coal sample; 105-Reaction chamber air inlet; 106-Reaction chamber inert gas injection port; 107-Reaction chamber inhibitor application port; 108-Reaction chamber temperature sensor interface; 109-Reaction chamber air outlet; 110-Stainless steel atomizing nozzle; 111-Temperature sensor one; 112-Temperature sensor two; 1 13-Lower perforated plate; 114-Upper perforated plate; 115-Power switch 1; 116-Programmed temperature rise parameter setting interface; 117-High temperature resistant support platform; 118-Cooling fan; 119-Insulation layer; 2-Multi-channel gas distribution and supply module; 201-Air tank; 202-Carbon dioxide tank 1; 203-Nitrogen tank 1; 204-Dynamic gas mixer; 205-Oxygen-containing mixed gas outlet pipe; 206-Mass flow meter; 207-Dynamic Gas mixing instrument parameter setting interface; 208-Pressure reducing valve; 209-Pressure gauge; 3-Inhibition medium supply module; 301-Constant flow injection pump; 302-Reservoir tank; 303-Inhibitor solution; 304-Pipeline; 305-Control valve; 306-Injector; 307-Corrosion resistant injection pipe; 308-Flow path switching valve; 309-Inhibitor liquid outlet pipe; 310-Carbon dioxide tank II; 311-Nitrogen tank II; 4-Temperature monitoring and... Online gas analysis module; 401-Paperless recorder; 402-Gas chromatograph; 403-Power switch II; 404-Temperature sensor signal output terminal I; 405-Temperature sensor signal output terminal II; 406-Sample inlet tube; 407-Chromatographic column; 408-Detector; 409-Dry air generator; 410-Hydrogen generator; 411-Gas drying tube; 412-Data acquisition and processing terminal; 413-Nitrogen cylinder III. Detailed Implementation

[0027] The present invention will be further described below with reference to an embodiment in the accompanying drawings: like Figure 1 As shown, the dynamic simulation experimental system for the entire process of coal spontaneous combustion-inhibition-reignition of the present invention mainly consists of a program temperature control and reaction chamber module 1, a multi-gas distribution and supply module 2, an inhibition medium supply module 3, and a temperature monitoring and online gas analysis module 4, which are connected as one unit. The aforementioned programmable temperature control and reaction chamber module 1 is key to enabling the coal sample to react under a controlled thermal environment, such as... Figure 2As shown; the core of the programmable temperature control and reaction chamber module 1 is the programmable temperature rise device 101 and the cylindrical high-temperature resistant stainless steel reaction chamber 102 placed inside it; the programmable temperature rise device 101 includes a programmable temperature rise parameter setting interface 116, a second temperature sensor 112, a first power switch 115, a high-temperature resistant support platform 117, a cooling fan 118, and a heat insulation layer 119; the programmable temperature rise device 101 can achieve precise temperature control with a temperature control accuracy of ±0.5℃, a maximum operating temperature of 400℃, and can achieve constant temperature control or multi-level gradient programmable temperature rise within the range of 30~400℃. The heating rate can be adjusted within the range of 0.4~40℃ / min with an adjustment accuracy of 0.1℃ / min, thereby providing a precise and controllable thermal environment for the coal sample. The programmed heating device 101 is model SP-6801A. The lower part of the reaction chamber 102 is provided with a reaction chamber air inlet 105 and a reaction chamber inert gas injection port 106. A lower perforated plate 113 is provided above the reaction chamber air inlet 105 and the reaction chamber inert gas injection port 106 to support the coal sample 104 and ensure that the reaction gas passes through the coal sample uniformly. The left side wall above the lower perforated plate 113 is provided with a reaction chamber inhibitor application port. 107, a reaction chamber temperature sensor interface 108 is provided on the right side wall. A stainless steel atomizing nozzle 110 is connected inside the reaction chamber inhibitor application port 107 for spraying liquid inhibitor droplets onto the coal sample. A temperature sensor 111 is provided inside the reaction chamber temperature sensor interface 108. An upper perforated plate 114 is provided above the stainless steel atomizing nozzle 110, covering the coal sample 104, to prevent coal dust from being blown out by the airflow and causing airway blockage. A reaction chamber air outlet 109 is provided on the reaction chamber wall above the upper perforated plate 114, and a sealing flange 103 is provided at the top. The high-temperature resistant bearing... Platform 117 is located inside the programmed heating device 101 and is used to house the reaction chamber 102. The programmed heating device 101 is started by the power switch 115, and the programmed heating parameter setting interface 116 is used to select the precise programmed heating, constant temperature, and adiabatic oxidation modes. The cooling fan 118 is installed on the top of the programmed heating device 101 and is used to force-cool the reaction chamber 102 and coal sample 104 after the experiment. The insulation layer 119 covers the inner or outer wall of the programmed heating device 101 to reduce heat loss and improve temperature control stability.

[0028] The reaction chamber 102 is placed on a high-temperature resistant support platform 117. The reaction chamber 102 adopts a high-temperature resistant stainless steel cylindrical structure with an inner diameter of Φ50mm and a height of 100mm. Its inner wall is polished to reduce gas flow resistance and prevent coal sample particles from adhering (see...). Figure 3The top of the reaction chamber 102 is sealed with a sealing flange 103 equipped with a high-temperature resistant sealing ring to achieve airtight closure, and the interior is used to fill coal samples 104; the air inlet 105 of the reaction chamber is connected to the oxygen-containing mixed gas outlet pipe 205 of the gas distribution and supply module 2, the inert gas injection port 106 of the reaction chamber is connected to the gas supply pipeline 304 of the inhibition medium supply module, the inhibitor application port 107 of the reaction chamber is connected to the inhibitor liquid outlet pipe 309 of the inhibition medium supply module 3, and the air outlet 109 of the reaction chamber is connected to the sample gas inlet 406 of the temperature monitoring and online gas analysis module 4; the program temperature control and reaction chamber module 1 is equipped with temperature sensor 111 and temperature sensor 204, both of which... All are armored thermocouples; temperature sensor 111 is inserted into the geometric center of coal sample 104 via reaction chamber temperature sensor interface 108 to collect and record the center temperature of the coal sample in real time; temperature sensor 112 is located inside the programmed heating device 101 and outside the reaction chamber 102 to collect and record the ambient temperature of the reaction chamber in real time; the signals from temperature sensor 111 and temperature sensor 112 are respectively led out through the coal core temperature sensor signal output terminal 120 and the ambient temperature sensor signal output terminal 121, and the two temperature sensors are connected to the paperless recorder 401 for communication, and the real-time temperature data is collected and recorded by the paperless recorder 401. Through the synchronous monitoring of temperature sensor 111 and temperature sensor 112, the center temperature of the coal sample and the ambient temperature of the reaction chamber can be obtained in real time, which is used to calculate the crossover temperature and determine the spontaneous combustion process of the coal.

[0029] The multi-channel gas distribution and supply module 2 provides precisely proportioned oxygen-containing mixed gas for the experiment to simulate the oxidation environment under different air leakage intensities in the goaf, such as... Figure 4As shown. The multi-channel gas distribution and supply module 2 includes a dynamic gas distributor 204 with a dynamic gas distributor parameter setting interface 207. One side of the dynamic gas distributor 204 is connected to pipelines of air tank 201, carbon dioxide tank 202, and nitrogen tank 203, respectively. The other side is provided with an oxygen-containing mixed gas outlet pipe 205 connected to the air inlet 105 of the reaction chamber. A mass flow meter 206 is provided on the oxygen-containing mixed gas outlet pipe 205. Dry air is provided by air tank 201, and inert gases are provided by carbon dioxide tank 202 and nitrogen tank 203, respectively. Each gas tank and the gas supply pipeline between the dynamic gas distributor 204 is provided with a pressure reducing valve 208 and a pressure gauge 209 in sequence to regulate the supply pressure of each gas and ensure stable intake pressure. The dynamic gas mixing instrument 204 can precisely control the mixing ratio of dry air, carbon dioxide, and nitrogen according to the set gas mixing parameters, thereby preparing an oxygen-containing mixed gas with a continuously adjustable oxygen volume concentration within the range of 5% to 21%. This is used to simulate various on-site air leakage conditions in coal mine goaf areas, ranging from normal ventilation areas to severely oxygen-deficient asphyxiation areas. The prepared oxygen-containing mixed gas is output through the oxygen-containing mixed gas outlet pipe 205. A mass flow meter 206 installed on this pipe is used to precisely control the total gas flow rate with a control accuracy of ±1% and a total flow rate adjustment range of 50~500 mL / min. Subsequently, the oxygen-containing mixed gas is transported through the pipeline to the air inlet 105 of the reaction chamber, entering the reaction chamber and fully contacting the coal sample 104.

[0030] The aforementioned inhibition medium supply module 3 is used to apply various inhibition media to the coal sample. This module supports dynamic application of the inhibition medium at any specified moment during the experiment when the preset oxidation characteristic temperature T1 or characteristic gas concentration threshold is reached, without opening the reaction chamber and disrupting the internal atmosphere, thus ensuring the continuity of the experimental process. Figure 5As shown; the inhibition medium supply module 3 includes an inhibitor application unit and an inert gas injection unit, and one or more injection units can be flexibly configured for individual or combined use according to experimental requirements; the inhibitor application unit is used to apply the inhibitor solution, including a constant flow injection pump 301 and a storage tank 302 containing the inhibitor solution 303; the constant flow injection pump 301 further includes a syringe 306 and a flow path switching valve 308 disposed on the syringe 306; the output rate of the constant flow injection pump 301 is adjustable in the range of 0.5~5mL / min, the total output is set in the range of 5~50mL, and the spray dosage control accuracy is ≤±0. 1 mL is provided to meet the requirements of inhibition experiments under different inhibitor types, concentrations, and application intensities. The left side of the flow path switching valve 308 is connected to the inhibitor application port 107 of the reaction chamber via the inhibitor liquid outlet pipe 309, and the right side is inserted into the storage tank 302 containing the inhibitor solution 303 via the corrosion-resistant injection pipe 307. The inhibitor solution 303 in the storage tank 302 is delivered to the inhibitor application port 107 of the reaction chamber at a constant flow rate and atomized by the stainless steel atomizing nozzle 110. The atomizing nozzle 110 can atomize the liquid inhibitor into fine droplets and spray them evenly onto the surface of the coal sample 104, with a spray coverage area of ​​not less than 90% of the coal sample surface area.

[0031] The inert gas injection unit utilizes high-pressure inert gas cylinders as a gas source, including a carbon dioxide cylinder 310 and a nitrogen cylinder 311, to inject inert gas into the reaction chamber 102 to establish an inert environment. A single inert gas or a mixture of both can be selected according to experimental needs. The carbon dioxide cylinder 310 and nitrogen cylinder 311 provide pure carbon dioxide and pure nitrogen. After the gas is reduced to a set pressure by a pressure reducing valve 208, it is collected through pipelines and then connected to the inert gas injection port 106 of the reaction chamber via a control valve 305 and a mass flow meter 206, which control the mixing ratio and total gas flow rate. The mixing ratio of carbon dioxide and nitrogen can be adjusted within the range of 1:9 to 9:1. The mass flow meter 206 accurately measures the gas flow rate, and the total inert gas flow rate is controlled within the range of 50~500 mL / min. By adjusting the injection flow rate and duration of the inert gas, an inert environment with an oxygen concentration ≤3% is established and maintained within the reaction chamber for cooling and temperature reduction of the coal sample and for synergistic inhibition treatment.

[0032] The temperature monitoring and online gas analysis module 4 is used for real-time acquisition and synchronous recording of key parameters throughout the experiment, such as... Figure 6As shown; the temperature monitoring and online gas analysis module 4 includes a paperless recorder 401, a gas chromatograph 402, a data acquisition and processing terminal 412, a dry air generator 409, a hydrogen generator 410, and a nitrogen tank 413; the paperless recorder 401 is equipped with a temperature sensor signal output terminal 404 connected to the temperature sensor interface 108 of the reaction chamber and a temperature sensor signal output terminal 405 connected to the temperature sensor 112 of the reaction chamber, which collects and records the temperature of the coal sample center and the ambient temperature of the reaction chamber in real time for subsequent extraction and analysis of characteristic temperature parameters; the gas chromatograph 402 includes a chromatographic column 407 installed in the chamber and a detector 408 installed at the bottom of the chamber, and a sample inlet pipe 406 connected to the gas outlet 109 of the reaction chamber is installed at the top of the chamber for online continuous monitoring and analysis of the concentration of multiple components in the exhaust gas; the carrier gas, combustion gas and fuel gas required for the operation of the gas chromatograph 402 are provided by the corresponding gas tanks. Dry air is provided by dry air generator 409, hydrogen by hydrogen generator 410, and high-purity nitrogen by external nitrogen tank 311. Both dry air generator 409 and hydrogen generator 410 are equipped with pressure gauges 209 and gas drying tubes 411 to monitor gas pressure and dry the gas, ensuring the stability and accuracy of gas chromatograph 402. The concentrations of the multi-component gases should include at least the concentrations of oxygen (O2), carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), ethane (C2H6), ethylene (C2H4), and acetylene (C2H2). The side of the gas chromatograph 402 is connected to dry air generator 409, hydrogen generator 410, and nitrogen tank 313 via pipelines. All temperature and gas concentration data are ultimately transmitted to data acquisition and processing terminal 412 for recording, storage, and analysis, achieving synchronous real-time monitoring of temperature and gas components, providing comprehensive and reliable data support for the study of coal spontaneous combustion mechanisms and the evaluation of suppression effectiveness.

[0033] Through the coordinated operation of the above modules, the system in this embodiment can completely simulate the entire dynamic process of coal from spontaneous combustion through oxidation, suppression treatment, to re-ignition, providing an experimental platform for the research and evaluation of coal mine spontaneous combustion fire prevention technology.

[0034] The present invention provides a dynamic simulation experimental method for the entire process of coal spontaneous combustion-inhibition-reignition, such as... Figure 7 As shown, it includes the following steps: S1. Coal Sample Preparation and Pretreatment: Fresh coal samples collected from underground are crushed and sieved under an inert atmosphere to obtain experimental coal sample 104 with a preset particle size range; the preset particle size is set to 60~200 mesh according to experimental requirements, corresponding to a particle size of 75~250μm; the coal sample is dried or vacuum degassed according to experimental requirements to remove physically adsorbed water and gas, and the treated coal sample is sealed and stored for later use.

[0035] S2, Coal sample oxidation and heating stage: according to... Figure 1 Connect all module pipes and circuits, ensuring all connections are properly sealed. Turn on nitrogen cylinder 202 and purge the entire gas path and reaction chamber at a high flow rate of 100 mL / min for 5-10 minutes to replace any residual air in the system. After purging, check the system's airtightness to ensure there are no gas leaks during the experiment. After accurate weighing, the prepared coal sample is loaded into the reaction chamber 102. The sample loading amount can be set according to experimental requirements. During loading, it should be ensured that the coal sample is evenly distributed in the reaction chamber and that the reaction chamber 102 is well sealed. The programmed heating device 101 is controlled through the programmed heating parameter setting interface 116 to heat from room temperature to the preset oxidation characteristic temperature T1 at a heating rate of 0.5~5℃ / min. The oxidation characteristic temperature T1 is a set value in the range of 50~400℃. The temperature is held at the oxidation characteristic temperature T1 for a set time of 0~12h to simulate the heating and isothermal oxidation process of the coal sample at different oxidation stages. At the same time, the dynamic gas distribution instrument 204 and the mass flow rate in the multi-gas distribution and supply module 2 are controlled. In step 206, based on the preset oxygen-containing mixed gas composition and flow rate requirements of the experiment, an oxygen-containing mixed gas with preset composition and flow rate is continuously introduced into the reaction chamber 102. The oxygen-containing mixed gas is a mixture of air tank 201, carbon dioxide tank 202, and nitrogen tank 203. The oxygen-containing mixed gas is a nitrogen-oxygen mixture with an oxygen volume concentration of 5%-21%, or a mixture of carbon dioxide and dry air. The oxygen volume concentration is precisely controlled by a dynamic gas distribution instrument 204 to simulate the oxygen-containing environment under different air leakage intensities in the goaf of a mine. The total flow rate of the oxygen-containing mixed gas is controlled within the range of 50~500 ml / min. This stage simulates the low-temperature oxidation and self-heating process of coal in the goaf environment.

[0036] S3, Inhibition and Cooling Stage: After the coal sample's center temperature reaches the oxidation characteristic temperature T1 and is held at a constant temperature, the programmed heating device 101 is turned off to stop heating, and the dynamic gas mixing instrument 204 is controlled to stop the introduction of oxygen-containing mixed gas. Then, the control valve 305 in the inhibition medium supply module 3 is controlled to introduce inert gas from the carbon dioxide tank 310 and nitrogen tank 310 in the inert gas injection unit into the reaction chamber 102, with the total gas flow rate controlled within the range of 50~500 ml / min. The coal sample 104 is inertized and cooled by continuously introducing inert gas into the reaction chamber 102. At the same time, the constant flow injection pump 301 in the inhibition medium supply module 3 is started, and the pre-prepared inhibitor solution 303 in the storage tank 302 is delivered to the stainless steel atomizing nozzle 110 through the flow path switching valve 308, and dynamically sprayed onto the surface of the coal sample in an atomized form to achieve the inhibition treatment of the coal sample. The inhibitor solution is output by the constant flow injection pump 301. The spraying rate of liquid 303 is controlled within the range of 0.5~5 ml / min, and the total output is controlled within the range of 5~50 ml, with a spraying dosage control accuracy of ≤±0.1 mL. The output rate and total output are independently controllable to achieve different application intensities and durations of inhibition treatment. After the experiment, the injection pipeline can be cleaned with deionized water and dried by ventilation to prevent residual inhibitor crystallization from clogging the pipeline. Under the synergistic effect of inert atmosphere cooling and inhibitor spraying, the coal sample temperature is rapidly reduced to room temperature or the preset reignition initiation temperature, completing the inhibition and cooling stage. Either of the above inhibition methods can be used alone or in combination, depending on experimental requirements, to achieve synergistic inhibition treatment of inert atmosphere cooling and inhibitor spraying. The cooling curve and gas concentration changes of the coal sample under inhibition measures are continuously monitored and recorded until the center temperature of the coal sample cools to the preset reignition initiation temperature T2 or reaches the set cooling time, completing the inhibition and cooling stage.

[0037] S4. Coal Sample Reignition Stage: After the coal sample 104 cools to the preset reignition initiation temperature T2, the constant flow injection pump 301 in the inhibition medium supply module 3 is turned off to stop the inhibitor spraying, and the control valve 305 is closed to stop the introduction of inert gas into the reaction chamber 102; simultaneously, the dynamic gas mixer 204 and mass flow meter 206 in the multi-channel gas distribution and supply module 2 are controlled to re-introduce the oxygen-containing mixed gas with preset components and flow rate into the reaction chamber 102; the oxygen volume concentration of the oxygen-containing mixed gas is adjustable in the range of 5% to 21%, and the total gas flow rate is controlled in the range of 50 to 500 mL / min. Subsequently, the programmed heating device 101 is started to perform a secondary programmed heating of the coal sample, heating it from the reignition initiation temperature T2 to the preset termination temperature at a heating rate of 0.5 to 5℃ / min, and the center temperature of the coal sample in the reaction chamber 102 is monitored in real time. The concentration and composition of the exhaust gas change until the coal sample reignites or reaches the preset experimental termination condition; the preset reignition initiation temperature T2 is lower than the oxidation characteristic temperature T1 in step S2, which is used to simulate the reignition behavior of the coal sample being exposed to the oxidizing environment before it has fully recovered to room temperature after inhibition cooling; the heating rate of the secondary programmed heating of the coal sample is consistent with the heating rate of step S2, controlled within the range of 0.5~5℃ / min, to ensure the comparability of the oxidation heating stage and the reignition stage; the reignition determination condition includes any one or more of the following situations: abnormal increase in CO gas concentration, such as the CO concentration continuing to rise and exceeding the preset threshold, a sudden rise in coal sample temperature, such as the heating rate exceeding the preset value, and the appearance of C2H4 or acetylene C2H2 characteristic gases; if no reignition characteristics appear after heating to the preset termination temperature, the experiment ends.

[0038] S5. Synchronous Monitoring of Data Throughout the Entire Experiment: During the entire experiment from steps S2 to S4, the experimental parameters are synchronously monitored and recorded throughout the entire process via data acquisition and monitoring module 4; specifically including: Temperature monitoring: The paperless recorder 401 continuously monitors and records the environmental temperature change data of the coal sample center and reaction chamber. The temperature sampling frequency is not less than 1 time / second, and the time-temperature change curve is generated in real time. Gas concentration monitoring: Gases discharged from the reaction chamber outlet 109 and those entering through the sample inlet pipe 406 are sampled and analyzed online using a gas chromatograph 402. Simultaneously, the concentration changes of O2, CO, CO2, and hydrocarbon gases, including CH4, C2H6, C2H4, and C2H2, are recorded. The detection accuracy of CO is ≤1ppm, and the detection accuracy of O2 is ≤0.1%. The sampling interval of the gas chromatograph is 5~30 minutes, and the sampling frequency is dynamically adjusted according to the experimental stage. Data recording and storage: Record and store the temperature change data and multi-component gas concentration change data obtained from the above-mentioned experiment, for subsequent analysis and evaluation of coal spontaneous combustion tendency, inhibitor inhibition effect and re-ignition characteristics; S6. Inhibition Efficiency Analysis and Evaluation: Based on the temperature change data and multi-component gas concentration change data obtained in step S5, the behavior characteristics of the coal sample in step S2 during the oxidation and heating stage, the inhibition and cooling stage in step S3, and the coal sample re-ignition stage in step S4 are analyzed. Characteristic temperature parameters and gas release characteristic parameters are extracted from the analysis, and an inhibition efficiency evaluation index system is established. Based on this, the comprehensive inhibition effect of the inhibition medium supply module 3 on the inhibitor or inert gas applied by the programmed temperature control and reaction chamber module 1 is quantitatively evaluated, and the optimal inhibitor type, concentration ratio, and application process parameters suitable for the target coal sample are selected.

[0039] The suppression effectiveness evaluation index system is established based on characteristic temperature parameters and gas release characteristic parameters, wherein: The characteristic temperature parameters include: oxidation characteristic temperature T1, re-ignition initiation temperature T2, crossover temperature, and the first detection temperature of the characteristic gas; the crossover temperature is the intersection point of the coal sample center temperature and the reaction chamber ambient temperature curve; the characteristic gases include CO, C2H4, and C2H2, and the first detection temperature is the corresponding temperature at which each characteristic gas is first detected by the gas chromatograph 402. The gas release characteristic parameters include: the oxygen consumption rate, CO generation rate, CO / CO2 ratio and C2H6 / C2H4 ratio calculated based on the time-varying laws of O2, CO, CO2, CH4, C2H6, C2H4 and C2H2 gas concentrations obtained by gas chromatograph 402; The inhibition effectiveness evaluation index system consists of inhibition rate, cooling efficiency, reignition inhibition index, characteristic temperature offset, and gas release inhibition coefficient, wherein: The inhibition rate is used to characterize the degree to which the inhibitor or inert gas inhibits the oxidation reaction rate of the coal sample. The cooling efficiency is used to characterize the rate and magnitude of temperature decrease in the coal sample after the application of inhibitors or inert gases during the inhibition and cooling stages. The reignition inhibition index is used to characterize the ease with which a coal sample is re-oxidized during the reignition stage and the intensity of the reignition. The characteristic temperature offset is used to characterize the change in the characteristic temperature (oxidation characteristic temperature T1, re-ignition initiation temperature T2, crossover temperature, and first detection temperature of characteristic gas) of the coal sample before and after the application of inhibitor or inert gas. The gas release inhibition coefficient is used to characterize the degree of change in the amount and rate of generation of characteristic gases before and after the application of an inhibitor or inert gases including CO, C2H4, and C2H2; By comparing the changes in characteristic temperature parameters and gas release characteristic parameters before and after applying different inhibitor solutions and injecting inert gas, the comprehensive inhibition performance of the inhibitor solution and inert gas is comprehensively evaluated based on five indicators: inhibition rate, cooling efficiency, reignition inhibition index, characteristic temperature shift, and gas release inhibition coefficient. Among them, the higher the inhibition rate, the higher the cooling efficiency, the higher the reignition inhibition index, the larger the characteristic temperature shift, and the higher the gas release inhibition coefficient, the better the inhibition effect.

[0040] This invention simulates the entire process of "oxidation-inhibition-re-oxidation" to achieve high-precision synchronous monitoring of temperature and multi-component gas products. It can completely reproduce the entire process of coal spontaneous combustion development, active inhibition, and post-inhibition re-ignition, providing a standardized experimental platform and analytical method for scientifically evaluating the long-term effectiveness of various fire prevention and extinguishing materials and processes, as well as the inhibitory efficacy of inhibitors.

Claims

1. A dynamic simulation experimental system for the entire process of coal spontaneous combustion-inhibition-reignition, characterized in that: It includes a programmable temperature control and reaction chamber module (1), a multi-channel gas distribution and supply module (2), an inhibition medium supply module (3), and a temperature monitoring and online gas analysis module (4). The programmed temperature control and reaction chamber module (1) includes a programmed heating device (101) and a cylindrical high-temperature resistant stainless steel reaction chamber (102) placed therein; the programmed heating device (101) includes a programmed heating parameter setting interface (116), a second temperature sensor (112), a high-temperature resistant support platform (117), a cooling fan (118), and a heat insulation layer (119); the reaction chamber (102) is placed on the high-temperature resistant support platform (117), and the lower part of the reaction chamber (102) is provided with a reaction chamber air inlet (105) and a reaction chamber inert gas injection port (106), and a coal sample carrier (106) is provided above the reaction chamber air inlet (105) and the reaction chamber inert gas injection port (106). 04) The lower perforated plate (113) has a reaction chamber inhibitor application port (107) on the left side wall above the lower perforated plate (113) and a reaction chamber temperature sensor interface (108) on the right side wall. A stainless steel atomizing nozzle (110) is connected to the reaction chamber inhibitor application port (107) to spray liquid inhibitor droplets onto the coal sample. A temperature sensor (111) is provided in the reaction chamber temperature sensor interface (108). An upper perforated plate (114) is provided above the stainless steel atomizing nozzle (110) and covers the coal sample (104). A reaction chamber air outlet (109) is provided on the reaction chamber wall above the upper perforated plate (114), and a sealing flange (103) is provided at the top. The multi-channel gas distribution and supply module (2) includes a dynamic gas distributor (204) with a dynamic gas distributor parameter setting interface (207). One side of the dynamic gas distributor (204) is connected to the pipelines of the air tank (201), the carbon dioxide tank (202) and the nitrogen tank (203) respectively. The other side is provided with an oxygen-containing mixed gas outlet pipe (205) connected to the air inlet (105) of the reaction chamber. A mass flow meter (206) is provided on the oxygen-containing mixed gas outlet pipe (205). The inhibition medium supply module (3) includes an inhibitor application unit and an inert gas injection unit; the inhibitor application unit includes a constant flow injection pump (301) for injecting inhibitor and a storage tank (302) containing inhibitor solution (303); the inert gas injection unit includes a carbon dioxide tank (310) and a nitrogen tank (311) for injecting inert gas into the reaction chamber (102) to establish an inert environment and to cool the coal sample (104); the carbon dioxide tank (310) and the nitrogen tank (311) provide pure carbon dioxide and pure nitrogen, which are respectively collected through pipelines and then passed through a control valve (305) for controlling the mixing ratio and the total gas flow rate. The mass flow meter (206) is connected to the inert gas injection port (106) of the reaction chamber via a pipeline; the constant flow injection pump (301) includes a syringe (306) and a flow path switching valve (308) on the syringe (306). The left side of the flow path switching valve (308) is connected to the inhibitor application port (107) of the reaction chamber via the inhibitor liquid outlet pipe (309), and the right side is inserted into the storage tank (302) containing the inhibitor solution (303) via the corrosion-resistant injection pipe (307); the inhibitor solution (303) in the storage tank (302) is delivered to the reaction chamber (102) at a constant flow rate, and is atomized by the stainless steel atomizing nozzle (110) and evenly sprayed onto the surface of the coal sample (104); The temperature monitoring and online gas analysis module (4) includes a paperless recorder (401), a gas chromatograph (402), a data acquisition and processing terminal (412), a dry air generator (409), a hydrogen generator (410), and a nitrogen tank (413). The paperless recorder (401) is equipped with a temperature sensor signal output terminal one (404) connected to the reaction chamber temperature sensor interface (108) and a temperature sensor signal output terminal two (405) connected to the temperature sensor two (112) on one side, for real-time acquisition and recording of the coal sample center and the ambient temperature of the reaction chamber. The gas chromatograph (402) includes a... The chamber contains a chromatographic column (407) and a detector (408) located at the bottom of the chamber. The top of the chamber is equipped with a sample inlet pipe (406) connected to the gas outlet (109) of the reaction chamber, which is used for online continuous monitoring and analysis of the concentration of multiple components in the exhaust gas. The concentration of the multiple components should include at least the concentrations of oxygen (O2), carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), ethane (C2H6), ethylene (C2H4), and acetylene (C2H2). The sides of the chamber are connected to a dry air generator (409), a hydrogen generator (410), and a nitrogen tank (413) via pipelines to achieve synchronous real-time monitoring of temperature and gas components.

2. The dynamic simulation experimental system for the entire process of coal spontaneous combustion-inhibition-reignition as described in claim 1, characterized in that: The programmed temperature rise device (101) includes a programmed temperature rise parameter setting interface (116), a power switch (115), a high-temperature resistant support platform (117), a cooling fan (118), and an insulation layer (119). The high-temperature resistant support platform (117) is located inside the programmed temperature rise device (101) and is used to place the reaction chamber (102). The cooling fan (118) is installed on the top of the programmed temperature rise device (101) and is used to force-cool the reaction chamber (102) after the experiment. Cooling; the insulation layer (119) covers the inner or outer wall of the programmed heating device (101) to reduce heat loss and improve temperature control stability; the programmed heating device (101) can achieve multi-level gradient heating and constant temperature control within the range of 30~400℃, with a heating rate of 0.4~40℃ / min and an adjustment accuracy of 0.1℃ / min, to meet the simulation requirements of the entire process of coal spontaneous combustion-inhibition-reignition under different heating rates; the model of the programmed heating device is SP-6801A.

3. The dynamic simulation experimental system for the entire process of coal spontaneous combustion-inhibition-reignition as described in claim 1, characterized in that: The reaction chamber (102) is a high-temperature resistant stainless steel cylindrical structure. Its inner wall is polished to reduce gas flow resistance and prevent coal sample particles from adhering. The bottom of the reaction chamber (102) is equipped with a lower perforated plate (113) and the top is equipped with an upper perforated plate (114). Both the upper perforated plate (114) and the lower perforated plate (113) are stainless steel plates with several through holes evenly distributed on them. The lower perforated plate (113) is used to support the coal sample (104), and the upper perforated plate (114) is used to prevent the coal sample from being blown out by the airflow and causing gas path blockage. The upper and lower perforated plates work together to achieve uniform distribution of gas entering the reaction chamber (102).

4. The dynamic simulation experimental system for the entire process of coal spontaneous combustion-inhibition-reignition as described in claim 1, characterized in that: The first temperature sensor (111) is an armored thermocouple, whose measuring end is inserted into the geometric center of the coal sample through the reaction chamber temperature sensor interface (108) for real-time acquisition and recording of the coal sample center temperature; the second temperature sensor (112) is an armored thermocouple, whose measuring end is located inside the programmed heating device (101) and outside the reaction chamber (102) for real-time acquisition and recording of the reaction chamber ambient temperature; through the synchronous monitoring of the first temperature sensor (111) and the second temperature sensor (112), the coal sample center temperature and the reaction chamber ambient temperature are obtained in real time for calculating the crossover point temperature and judging the coal spontaneous combustion process.

5. The dynamic simulation experimental system for the entire process of coal spontaneous combustion-inhibition-reignition as described in claim 1, characterized in that: The volume ratio of pure carbon dioxide and pure nitrogen provided by the carbon dioxide tank 2 (310) and nitrogen tank 2 (311) is 1:9 to 9:1; the spraying dosage control accuracy of the constant flow injection pump (301) is ≤±0.1ml, the output rate of the constant flow injection pump (301) is 0.5~5ml / min, and the total output is 5~50ml, so as to achieve inhibition treatment with different application intensities and application durations.

6. A dynamic simulation experimental method for the entire process of coal spontaneous combustion-inhibition-reignition using the system described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Coal sample preparation and pretreatment: Fresh coal samples collected from underground are crushed and sieved under an inert atmosphere to obtain experimental coal samples (104) with a preset particle size range. S2, Coal Sample Oxidation and Heating Stage: The prepared coal sample (104) is loaded into the reaction chamber (102), and the reaction chamber (102) is sealed well; the dynamic gas mixer (204) and mass flow meter (206) in the multi-channel gas distribution and supply module (2) are controlled to continuously supply oxygen-containing mixed gas with preset components and flow rates to the reaction chamber (102) according to the preset oxygen-containing mixed gas components and flow rates. The oxygen-containing mixed gas is an air tank (201) and a carbon dioxide tank (202). The mixed gas with nitrogen tank 1 (203); at the same time, the program heating device (101) is started, and the program heating device (101) is controlled by the program heating parameter setting interface (116) to heat the room temperature to the preset oxidation characteristic temperature T1 at a heating rate of 0.5~5℃ / min. The oxidation characteristic temperature T1 is a certain set value in the range of 50~400℃, and the temperature is kept constant at the oxidation characteristic temperature T1 for a set time of 0~12h to simulate the heating and constant temperature oxidation process of coal sample at different oxidation stages; S3, Inhibition and Cooling Stage: After the coal sample temperature reaches the oxidation characteristic temperature T1 and is kept at a constant temperature, the programmed heating device (101) is turned off to stop heating, and the dynamic gas distribution device (204) is controlled to stop the introduction of oxygen-containing mixed gas; then the control valve (305) in the inhibition medium supply module (3) is controlled to introduce inert gas supplied by carbon dioxide tank two (310) and nitrogen tank two (310) in the inert gas injection unit into the reaction chamber (102); at the same time, the inhibition medium supply is started. The constant flow injection pump (301) in module (3) delivers the pre-prepared inhibitor solution (303) in the storage tank (302) to the stainless steel atomizing nozzle (110) through the flow path switching valve (308) to dynamically spray the surface of the coal sample (104) to achieve chemical inhibition treatment of the coal sample; under the synergistic effect of inert gas cooling and inhibitor solution (303) spraying, the temperature of the coal sample (104) is reduced to room temperature or the preset re-ignition initiation temperature T2, completing the inhibition and cooling stage; S4. Coal sample re-ignition stage: After the coal sample (104) cools to the preset re-ignition initiation temperature T2, the constant flow injection pump (301) in the inhibition medium supply module (3) is turned off, the inhibitor spraying is stopped, and the control valve (305) is turned off to stop the inert gas from being introduced into the reaction chamber (102). At the same time, the dynamic gas distribution instrument (204) and mass flow meter (206) in the multi-channel gas distribution and supply module (2) are controlled to re-introduce the oxygen-containing mixed gas with preset components and flow rate into the reaction chamber (102). Subsequently, the programmed heating device (101) is started to perform a second programmed heating on the coal sample, heating it from the re-ignition initiation temperature T2 to the preset termination temperature at a heating rate of 0.5~5℃ / min. The composition and concentration of the gas discharged from the gas outlet (109) of the reaction chamber are monitored in real time until the coal sample re-ignites or reaches the preset experimental termination temperature, and the experiment ends. S5. Synchronous Monitoring of Data Throughout the Experiment: During the entire experimental process from steps S2 to S4, the experimental parameters are synchronously monitored and recorded throughout the entire process via the data acquisition and monitoring module (4); specifically including: Temperature monitoring: The temperature change data of the coal sample center and reaction chamber are continuously monitored and recorded by a paperless recorder (401), and the time-temperature change curve is generated in real time. Gas concentration monitoring: The gas discharged from the gas outlet (109) of the reaction chamber and the gas entering through the sample inlet pipe (406) are sampled and analyzed online by a gas chromatograph (402), and the concentration change data of multiple components are recorded simultaneously. Data recording and storage: Record and store the temperature change data and multi-component gas concentration change data obtained from the above-mentioned experiment, for subsequent analysis and evaluation of coal spontaneous combustion tendency, inhibitor inhibition effect and re-ignition characteristics; S6. Analysis and evaluation of inhibition effectiveness: Based on the temperature change data and multi-component gas concentration change data obtained in step S5, the behavior characteristics of the coal sample in step S2 during the oxidation and heating stage, the inhibition and cooling stage in step S3, and the re-ignition stage in step S4 are analyzed. Characteristic temperature parameters and gas release characteristic parameters are extracted, and an inhibition effectiveness evaluation index system including inhibition rate, cooling efficiency, re-ignition inhibition index, characteristic temperature offset, and gas release inhibition coefficient is constructed. Based on this index system, the comprehensive inhibition effect of the inhibition medium supply module (3) on the inhibitor or inert gas applied by the programmed temperature control and reaction chamber module (1) is quantitatively evaluated, so as to select the best inhibitor type, concentration ratio and application process parameters suitable for the target coal sample.

7. The dynamic simulation experimental method for the entire process of coal spontaneous combustion-inhibition-reignition as described in claim 6, characterized in that: The reaction chamber (102) is continuously supplied with an oxygen-containing mixed gas of a preset composition and flow rate. The oxygen-containing mixed gas is a nitrogen-oxygen mixed gas with an oxygen volume concentration of 5%-21%, or a carbon dioxide and dry air mixed gas. The oxygen volume concentration is precisely controlled by a dynamic gas mixing instrument (204) to simulate the oxygen-containing environment under different air leakage intensities in the goaf of the mine. The total flow rate of the oxygen-containing mixed gas is controlled within the range of 50~500 ml / min. The total flow rate of the inert gas is controlled within the range of 50~500 ml / min. The output rate of the inhibitor solution (303) is controlled within the range of 0.5~5 ml / min, and the total output is controlled within the range of 5~50 ml. The output rate and the total output are independently controllable to achieve inhibition treatment with different application intensities and application durations. The inhibitor solution (303) is uniformly sprayed onto the surface of the coal sample in an atomized form through a stainless steel atomizing nozzle (110), and the spray coverage area is not less than 90% of the surface area of ​​the coal sample.

8. The dynamic simulation experimental method for the entire process of coal spontaneous combustion-inhibition-reignition as described in claim 6, characterized in that: The preset re-ignition initiation temperature T2 is lower than the oxidation characteristic temperature T1 in step S2, used to simulate the re-ignition behavior of coal samples that have not fully recovered to room temperature after inhibition cooling and are re-exposed to oxidative conditions; the heating rate of the secondary programmed heating of the coal sample is consistent with the heating rate of step S2, controlled within the range of 0.5~5℃ / min, to ensure the comparability of the oxidation heating stage and the re-ignition stage; the multi-component gas concentration change data includes the concentrations of O2, CO, CO2, CH4, C2H6, C2H4, and C2H2, wherein the detection accuracy of CO is ≤1 ppm and the detection accuracy of O2 is ≤0.1%; the sampling interval of the gas chromatograph (402) is 10~30 minutes / time, and the sampling interval is dynamically adjusted according to experimental needs.

9. The dynamic simulation experimental method for the entire process of coal spontaneous combustion-inhibition-reignition as described in claim 6, characterized in that: In step S6, the suppression effectiveness evaluation index system is established based on characteristic temperature parameters and gas release characteristic parameters, wherein: The characteristic temperature parameters include: oxidation characteristic temperature T1, re-ignition initiation temperature T2, crossover temperature, and the first detection temperature of the characteristic gas; the crossover temperature is the intersection point of the coal sample center temperature and the reaction chamber ambient temperature curve; the characteristic gases include CO, C2H4, and C2H2, and the first detection temperature is the corresponding temperature at which each characteristic gas is first detected by the gas chromatograph (402); The gas release characteristic parameters include: the oxygen consumption rate, CO generation rate, CO / CO2 ratio and C2H6 / C2H4 ratio calculated based on the time variation law of O2, CO, CO2, CH4, C2H6, C2H4 and C2H2 gas concentrations obtained by gas chromatograph (402); The inhibition effectiveness evaluation index system consists of inhibition rate, cooling efficiency, reignition inhibition index, characteristic temperature offset, and gas release inhibition coefficient, wherein: The inhibition rate is used to characterize the degree to which the inhibitor or inert gas inhibits the oxidation reaction rate of the coal sample. The cooling efficiency is used to characterize the rate and magnitude of temperature decrease in the coal sample after the application of inhibitors or inert gases during the inhibition and cooling stages. The reignition inhibition index is used to characterize the ease with which a coal sample is re-oxidized during the reignition stage and the intensity of the reignition. The characteristic temperature offset is used to characterize the change in the characteristic temperature of the coal sample before and after the application of the inhibitor or inert gas, namely the change in the oxidation characteristic temperature T1, the re-ignition initiation temperature T2, the crossover temperature, and the first detection temperature of the characteristic gas. The gas release inhibition coefficient is used to characterize the degree of change in the amount and rate of generation of characteristic gases before and after the application of an inhibitor or inert gases including CO, C2H4, and C2H2; By comparing the changes in characteristic temperature parameters and gas release characteristic parameters before and after applying different inhibitor solutions and injecting inert gas, the comprehensive inhibition performance of inhibitor solutions and inert gases is evaluated based on five indicators: inhibition rate, cooling efficiency, reignition inhibition index, characteristic temperature shift, and gas release inhibition coefficient. Among them, higher inhibition rate, higher cooling efficiency, higher reignition inhibition index, larger characteristic temperature shift, and higher gas release inhibition coefficient indicate better inhibition effect.

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