Coal spontaneous combustion carbon monoxide concentration simulation monitoring experiment system and method

Abstract

This invention relates to the field of coal mine safety monitoring technology, and particularly to an experimental system and method for simulating and monitoring carbon monoxide concentration during spontaneous combustion in coal. The system includes: a sealed cylinder for holding a coal sample; a stress loading component for applying crushing stress to the coal sample and monitoring the grinding power in real time; an atmosphere control component for vacuuming the cylinder and introducing a preset gas; a temperature control component for controlling the temperature inside the cylinder to the conditions experienced during coal mining; a gas sampling component for collecting the total carbon monoxide concentration inside the cylinder in real time; and a data analysis component for determining the carbon monoxide concentration generated by mechanical crushing based on the grinding power, and obtaining the carbon monoxide concentration generated by spontaneous combustion oxidation based on the carbon monoxide concentration generated and the total carbon monoxide concentration. The technical solution of this invention can effectively avoid false alarms caused by carbon monoxide from normal coal cutting, improving the accuracy and reliability of early warning systems.

Description

Technical Field

[0001] This invention relates to the field of coal mine safety monitoring technology, and in particular to an experimental system and method for simulating and monitoring carbon monoxide concentration during spontaneous combustion of coal. Background Technology

[0002] Carbon monoxide (CMO) is a key indicator of spontaneous combustion in underground coal mines, and its abnormal concentration is often used as a warning sign. Field practice has revealed that even in working faces without a risk of spontaneous combustion, significant increases in CMO concentration can be detected during coal cutting operations. Research indicates that this CMO primarily originates from three sources: CMO generated by the strong crushing action of mining machinery on the coal seam, leading to the breakage of oxygen-containing functional groups; CMO generated by the low-temperature oxidation reaction between coal and oxygen; and naturally occurring CMO in some coal seams. The simultaneous presence and superposition of these three sources of CMO underground severely interferes with the accuracy of spontaneous combustion warnings based on CMO concentration, easily leading to false alarms or missed detections. Current technologies typically set a fixed CMO concentration threshold; when the monitored value exceeds this threshold, a risk of spontaneous combustion is identified. However, these methods do not consider the contribution of mechanically broken CMO generated during coal cutting, resulting in frequent false alarms during normal coal cutting operations.

[0003] Therefore, there is an urgent need to develop a new technical solution to solve the above-mentioned technical problems. Summary of the Invention

[0004] This invention provides an experimental system and method for simulating and monitoring carbon monoxide concentration in coal spontaneous combustion, which can effectively avoid false alarms caused by carbon monoxide breakage generated during normal coal cutting, and improve the accuracy and reliability of early warning.

[0005] In a first aspect, the present invention provides an experimental system for simulating and monitoring carbon monoxide concentration during spontaneous combustion of coal, comprising: A sealed cylinder used to hold coal samples; A stress loading component, connected to the cylinder, is used to apply simulated mechanical crushing stress to the coal sample inside the cylinder, and to monitor the grinding power in real time during the crushing process. An atmosphere control component, connected to the cylinder, is used to perform vacuuming and gas introduction into the cylinder to maintain the atmosphere conditions required for coal mining. A temperature control component, connected to the cylinder, is used to control the temperature inside the cylinder to the temperature conditions during coal mining. A gas sampling component, connected to the cylinder, is used to collect the total carbon monoxide concentration inside the cylinder in real time; The data analysis component is connected to the stress loading component, atmosphere control component, temperature control component and gas sampling component respectively, and is used to determine the concentration of carbon monoxide generated by mechanical crushing based on the grinding power, and to obtain the concentration of carbon monoxide generated by spontaneous combustion oxidation based on the concentration of carbon monoxide generated and the total concentration of carbon monoxide.

[0006] In a second aspect, the present invention provides an experimental method for simulating and monitoring carbon monoxide concentration during spontaneous combustion of coal, applied to the system described in the first aspect of the present invention, the method comprising: Place the coal sample inside a sealed cylinder; The mechanical crushing stress simulating that during coal mining is applied to the coal sample inside the cylinder, and the grinding power during the crushing process is monitored in real time. After the cylinder is evacuated, a preset gas is introduced to maintain the atmosphere conditions inside the cylinder during coal mining. The temperature inside the cylinder is controlled to the temperature conditions during coal mining. Real-time monitoring of the total carbon monoxide concentration inside the cylinder; The concentration of carbon monoxide generated by mechanical crushing is determined based on the grinding power, and the concentration of carbon monoxide generated by spontaneous combustion oxidation is obtained based on the total concentration of carbon monoxide and the concentration of carbon monoxide generated by mechanical crushing.

[0007] This invention provides a simulation monitoring system and method for carbon monoxide concentration in coal spontaneous combustion. By constructing a simulation monitoring system comprising a sealed cylinder, a stress loading component, an atmosphere control component, a temperature control component, a gas sampling component, and a data analysis component, the system can simulate the real environment of mechanical crushing and spontaneous combustion oxidation during coal mining. The stress loading component monitors the grinding power in real time, and combined with the total carbon monoxide concentration collected by the gas sampling component, the data analysis component can quantitatively separate the carbon monoxide concentration generated by mechanical crushing and the carbon monoxide concentration generated by spontaneous combustion oxidation, solving the problem of indistinguishability between the two sources of carbon monoxide in existing technologies. Based on the spontaneous combustion oxidation carbon monoxide concentration obtained by this system, accurate oxidation signals can be provided for early warning of spontaneous combustion in coal mines, effectively avoiding false alarms caused by carbon monoxide from normal coal cutting, and improving the accuracy and reliability of early warning. Attached Figure Description

[0008] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1This is a schematic diagram of a coal spontaneous combustion carbon monoxide concentration simulation monitoring experimental system provided in an embodiment of the present invention; Figure 2 It is based on Figure 1 The flowchart shows an experimental method for simulating and monitoring carbon monoxide concentration during spontaneous combustion of coal.

[0010] Figure label: 1-Cylinder body; 2-Stress loading components; 3-Atmosphere control components; 4-Temperature control components; 5-Gas sampling assembly; 6-Data Analysis Components. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0012] Please refer to Figure 1 This invention provides a coal spontaneous combustion carbon monoxide concentration simulation monitoring experimental system, comprising: A sealed cylinder 1 is used to hold coal samples; The stress loading component 2 is connected to the cylinder 1 and is used to apply simulated mechanical crushing stress to the coal sample inside the cylinder 1, and to monitor the grinding power in real time during the crushing process. Atmosphere control component 3 is connected to cylinder 1 and is used to perform vacuuming and gas injection inside cylinder 1 to maintain the atmosphere conditions inside cylinder 1 during coal mining. Temperature control component 4 is connected to cylinder 1 and is used to control the temperature inside cylinder 1 to the temperature conditions during coal mining. Gas sampling component 5 is connected to cylinder 1 and is used to collect the total concentration of carbon monoxide in cylinder 1 in real time. The data analysis component 6 is connected to the stress loading component 2, the atmosphere control component 3, the temperature control component 4, and the gas sampling component 5, respectively. It is used to determine the concentration of carbon monoxide produced by mechanical crushing based on the grinding power, and to obtain the concentration of carbon monoxide produced by spontaneous combustion oxidation based on the concentration of carbon monoxide produced and the total concentration of carbon monoxide.

[0013] In this embodiment of the invention, the cylinder 1 is made of stainless steel and is used to hold the coal sample to be tested. The cylinder 1 has good airtightness and pressure bearing capacity, and can simulate the closed space environment of an underground coal mine. The stress loading component 2 is used to simulate the crushing effect of the coal mining machine on the underground coal sample, applying simulated mechanical crushing stress to the coal sample in the cylinder 1, and monitoring the grinding power in real time during the crushing process. The atmosphere control component 3 is used to eliminate interference from other gases in the cylinder 1, perform vacuum treatment and introduce preset gas treatment in the cylinder 1 to maintain the atmosphere conditions in the cylinder 1 during coal mining, simulating the underground gas environment. The temperature control component 4 simulates the coal oxidation process under different ambient temperatures, controlling the temperature in the cylinder 1 to the temperature conditions during coal mining. The gas sampling component 5 is used to collect the total carbon monoxide concentration in the cylinder 1 in real time. The data analysis component 6 is used to calculate the carbon monoxide concentration caused by mechanical crushing based on the total carbon monoxide concentration in the cylinder 1 and various environmental parameters, and then obtain the carbon monoxide concentration produced by spontaneous combustion oxidation.

[0014] Specifically, fresh coal samples are collected from underground coal mines, sealed, and transported to the laboratory. The coal samples are cut or crushed into blocks suitable for the size of cylinder 1, and basic information such as the source, depth, and coal type are recorded. The processed coal samples are placed inside the sealed cylinder 1, and the cylinder's airtightness is checked to ensure there are no leaks. The atmosphere control component 3 is activated to first evacuate cylinder 1, removing the original air; then, a preset gas (such as air simulating the atmosphere of a goaf) is introduced into cylinder 1 to maintain the atmosphere conditions used during coal mining. The temperature control component 4 is activated to adjust and maintain the temperature of cylinder 1 at the preset coal mining temperature conditions, simulating the underground environment temperature. The stress loading component 2 is activated to apply mechanical crushing stress simulating that used during coal mining to the coal samples inside cylinder 1, while simultaneously monitoring the grinding power during the crushing process in real time. During crushing, the coal samples are subjected to shear force and pressure, producing a crushing effect, simulating the action of the cutting teeth of a coal mining machine on the coal body. During and after crushing, the total carbon monoxide concentration inside cylinder 1 is collected in real time using the gas sampling component 5. Gas sampling can be performed continuously at preset time intervals to capture dynamic changes in carbon monoxide concentration. The collected grinding power and total carbon monoxide concentration data are transmitted to data analysis component 6. Data analysis component 6 first determines the carbon monoxide concentration generated by mechanical crushing based on the grinding power, then subtracts the carbon monoxide concentration generated by mechanical crushing and the background concentration from the total carbon monoxide concentration to obtain the carbon monoxide concentration generated by spontaneous combustion oxidation. Through these steps, quantitative separation of carbon monoxide from mechanical crushing and spontaneous combustion oxidation is achieved, obtaining the carbon monoxide concentration generated by spontaneous combustion oxidation, providing data support for early warning of spontaneous combustion in coal mines.

[0015] In one embodiment of the present invention, the stress loading component 2 includes: A planetary ball mill, located outside the cylinder 1, is used to apply controllable mechanical crushing energy to the coal sample inside the cylinder 1; A vibration mechanism, located outside the cylinder 1, is used to apply shear force to the coal sample; A power sensor is used to monitor the grinding power in real time during the crushing process; Torque sensor, used to monitor torque in real time during the crushing process; A speed sensor is used to monitor the rotational speed during the crushing process in real time.

[0016] In this embodiment, a planetary ball mill is located outside the cylinder 1, while the grinding elements are located inside the cylinder 1. Controllable mechanical crushing energy is applied to the coal sample by driving the grinding elements, simulating the impact and grinding action of coal mining machine cutting teeth on the coal body. A vibration mechanism is also located outside the cylinder 1, used to apply shear force to the coal sample in the horizontal direction through friction. A certain structural strength is required in the vertical direction to provide shear force through vibration. A power sensor is used to monitor the grinding power in real time during the crushing process, providing input parameters for subsequent calculations of the carbon monoxide concentration generated by mechanical crushing. A torque sensor is used to monitor the torque in real time during the crushing process, and a speed sensor is used to monitor the rotational speed in real time. By monitoring torque and speed, the accuracy of the input power can be further verified, and it can also be used to calibrate the mechanical response characteristics of different coal types under different crushing conditions.

[0017] Specifically, a power sensor monitors the voltage and current of the drive motor. The grinding power is obtained by multiplying the voltage by the current and then by the power factor. Alternatively, the grinding power can be calculated using the torque monitored by a torque sensor and the rotational speed monitored by a speed sensor: Grinding power = Torque × Angular velocity, where the angular velocity is converted from the rotational speed. The crushing energy is obtained by integrating the grinding power over time. In discrete sampling, the crushing energy is obtained by multiplying the grinding power at each sampling moment by the sampling time interval and then summing over all sampling points. It should be noted that grinding power represents the rate of crushing energy input per unit time, and crushing energy represents the total input energy. In the calculations of this invention, the instantaneous grinding power is used to determine the rate of carbon monoxide production during the current crushing process.

[0018] In one embodiment of the present invention, the atmosphere control component 3 includes: A vacuum pump, connected to cylinder 1 via a pipeline, is used to evacuate cylinder 1. The gas source is connected to the cylinder 1 through a pipeline and is used to introduce a preset gas into the cylinder 1. The airflow controller is installed on the pipeline between the air source and the cylinder 1 to control the on / off state and magnitude of the gas flow in the cylinder 1.

[0019] In this embodiment, a vacuum pump is connected to cylinder 1 via a pipeline to evacuate cylinder 1 before the experiment begins, removing the original air and other interfering gases inside cylinder 1, bringing the interior of cylinder 1 to a near-vacuum state, and providing a pure experimental environment for the subsequent introduction of a preset gas. A gas source is also connected to cylinder 1 via a pipeline to introduce a preset gas into cylinder 1. Depending on the experimental purpose, the preset gas can be air simulating a goaf atmosphere (containing a certain proportion of oxygen) or an inert gas (such as high-purity nitrogen). When an inert gas is introduced, it is used for an oxygen-free crushing experiment to calibrate the carbon monoxide concentration generated by purely mechanical crushing; when a simulated goaf atmosphere is introduced, it is used for a programmed temperature-increasing oxidation experiment to calibrate the carbon monoxide concentration generated by spontaneous combustion oxidation at different temperatures. An airflow controller is installed on the pipeline between the gas source and cylinder 1 to precisely control the flow rate of gas entering cylinder 1 and the gas flow rate. At the start of the experiment, the vacuum pump is activated to evacuate cylinder 1, and the vacuum pump is turned off after the gas pressure inside cylinder 1 drops to a preset value. Turn on the gas source and airflow controller, and introduce the target gas into cylinder 1 at the preset flow rate to maintain the atmosphere conditions used in coal mining. During the experiment, the opening of the airflow controller can be adjusted at any time as needed to change the gas flow rate or achieve on / off control.

[0020] In one embodiment of the present invention, the temperature control component 4 includes: An electric heating jacket is wrapped around the outer wall of the cylinder 1 and is used to heat the cylinder 1. Thermocouples are installed inside cylinder 1 to monitor the temperature inside cylinder 1 in real time; The PID temperature controller is electrically connected to the electric heating jacket and the thermocouple, respectively. It is used to control the heating power of the electric heating jacket according to the temperature feedback from the thermocouple, so as to maintain the temperature inside the cylinder 1 at the temperature conditions during coal mining.

[0021] In this embodiment, an electric heating jacket is wrapped around the outer wall of the cylinder 1 to uniformly heat the cylinder 1. A thermocouple is installed inside the cylinder 1 to monitor the temperature inside the cylinder 1 in real time. A PID temperature controller is electrically connected to both the electric heating jacket and the thermocouple, and is used to automatically adjust the heating power of the electric heating jacket according to the temperature signal fed back by the thermocouple, so that the temperature inside the cylinder 1 is precisely maintained at the temperature conditions during coal mining. Specifically, in the programmed temperature rise oxidation experiment, the PID temperature controller automatically controls the temperature change according to the preset temperature rise rate to simulate the coal oxidation process under different ambient temperatures; in the anaerobic crushing experiment, the PID temperature controller keeps the temperature constant at the original temperature collected underground, eliminating the interference of temperature changes on the crushing experiment.

[0022] In one embodiment of the present invention, the gas sampling component 5 includes: An automatic sampling valve, connected to cylinder 1, is used to collect gas inside cylinder 1; A gas chromatograph, connected to an automatic sampling valve, is used to analyze the composition and concentration of each component of the gas inside cylinder 1. An infrared CO analyzer, connected to an automatic sampling valve, is used to continuously monitor the total concentration of carbon monoxide in the gas.

[0023] In this embodiment, an automatic sampling valve is connected to cylinder 1 and is used to automatically collect gas inside cylinder 1 at preset time intervals. A gas chromatograph is connected to the automatic sampling valve and is used to analyze the concentration of multiple components in the collected gas, including characteristic gases such as methane, ethylene, and acetylene. An infrared CO analyzer is connected to the automatic sampling valve and is used to continuously monitor the total concentration of carbon monoxide in the gas.

[0024] During the experiment, the automatic sampling valve opened periodically at a set frequency, sending the gas inside cylinder 1 into the gas chromatograph and the infrared CO analyzer, respectively. The gas chromatograph was used to obtain detailed data on the gas composition. The infrared CO analyzer was used to monitor the dynamic changes in the total carbon monoxide concentration in real time.

[0025] In one embodiment of the present invention, the concentration of carbon monoxide generated due to mechanical crushing is calculated using the following formula: for The concentration of carbon monoxide produced by constant mechanical crushing. for Grinding power at all times This represents the CO production per unit of energy input. Let be the decay time constant of carbon monoxide release after mechanical crushing. This represents the volume of gas introduced into cylinder 1 per unit time. This is the preset reference gas flow rate.

[0026] In this embodiment, after the coal sample is mechanically crushed, it will continuously release carbon monoxide. This release will not disappear immediately after the crushing stops, but will gradually decrease over time. This represents the remaining amount of mechanically broken carbon monoxide from the previous moment after decay, reflecting the "memory effect" of the continuous release of carbon monoxide from the fresh surface after breakage. Simultaneously, the carbon monoxide generated during breakage is diluted by the airflow within cylinder 1, and the actual monitored concentration is also related to the ventilation volume: the greater the ventilation volume, the more pronounced the dilution effect, and the lower the monitored concentration. This represents the actual contribution of carbon monoxide generated by the new crushing at this moment after being diluted by ventilation. Adding the two parts together gives the total concentration of carbon monoxide generated by mechanical crushing at this moment.

[0027] In one embodiment of the present invention, the concentration of carbon monoxide generated by spontaneous combustion oxidation is calculated using the following formula: The concentration of carbon monoxide produced by spontaneous combustion oxidation. This represents the total concentration of carbon monoxide. This refers to the carbon monoxide concentration produced by mechanical crushing. The background carbon monoxide concentration is used as a reference.

[0028] In this embodiment, the carbon monoxide concentration produced by the spontaneous combustion oxidation reaction of coal and oxygen is obtained by subtracting the mechanically broken carbon monoxide concentration generated by the stress loading component 2 from the total carbon monoxide concentration measured by the gas sampling component 5, and then subtracting the background carbon monoxide concentration in the environment. In the cylinder 1 of this experimental system, the background carbon monoxide concentration is zero due to the vacuum treatment performed before the experiment. However, in actual coal mining processes, the background carbon monoxide concentration is a non-negligible value.

[0029] In one embodiment of the present invention, the data analysis component 6 is further configured to: Based on the real-time temperature value inside cylinder 1, the theoretical carbon monoxide concentration corresponding to the real-time temperature value is obtained; The product of the theoretical spontaneous combustion carbon monoxide concentration and the safety factor is calculated and used as the warning threshold. An alarm signal is issued when the concentration of carbon monoxide produced by spontaneous combustion exceeds the warning threshold.

[0030] In this embodiment, based on the real-time temperature value inside cylinder 1, the theoretical carbon monoxide concentration corresponding to that temperature is determined through a pre-calibrated temperature-concentration relationship. This theoretical value reflects the carbon monoxide concentration level that should be produced during normal oxidation of the coal sample under the current temperature conditions. The theoretical carbon monoxide concentration from spontaneous combustion is multiplied by a preset safety factor to obtain the warning threshold. The safety factor is a value greater than 1 and can be set based on historical mine data or field experience to avoid false alarms caused by measurement errors or normal fluctuations. The carbon monoxide concentration produced by spontaneous combustion is compared with the warning threshold: if the carbon monoxide concentration from spontaneous combustion exceeds the warning threshold, it is determined to be an oxidation anomaly, and an alarm signal is issued; if it does not exceed the threshold, it is determined to be normal oxidation, and no alarm is issued.

[0031] In one embodiment of the present invention, the theoretical spontaneous combustion carbon monoxide concentration is calculated using the following formula: The theoretical concentration of carbon monoxide for spontaneous combustion. This represents the coal sample temperature corresponding to the real-time temperature value. This represents the volume fraction of oxygen. The fitting factor for the oxidation experiment. To fit the activation energy in the oxidation experiment, n The reaction order is... To effectively reflect specific surface area, is the gas constant.

[0032] In this embodiment, the carbon monoxide formation rate of the coal oxy-oxidation reaction exhibits an exponential relationship with temperature. Higher temperatures result in more reactive coal molecules, a faster oxidation reaction, and a higher carbon monoxide formation rate. Besides temperature, the carbon monoxide formation rate is also related to several other factors: first, oxygen concentration—the more abundant the oxygen, the more vigorous the oxidation reaction; second, the effective reaction surface area of ​​the coal sample—the more fragmented the coal sample and the more fresh its surface area, the faster the reaction rate; and third, the inherent oxidation characteristics of the coal type—different coal types exhibit different oxidation activities, which are corrected for using experimentally fitted parameters.

[0033] Integrating the above factors, a formula for calculating the theoretical carbon monoxide concentration in spontaneous combustion oxidation is obtained. In this formula, the oxygen volume fraction reflects the concentration level of reactants in the oxidation reaction; the oxidation experiment fitting factor reflects the oxidation activity characteristics of the coal itself, and the fitting factor varies for different coal types; this parameter is obtained by fitting data from programmed temperature-increasing oxidation experiments; the oxidation experiment fitting activation energy reflects the energy barrier required for the coal oxidation reaction; the lower the activation energy, the easier the reaction occurs and the faster the carbon monoxide generation rate; this parameter is also obtained by fitting data from programmed temperature-increasing oxidation experiments; the reaction order indicates the degree of influence of oxygen concentration on the oxidation reaction rate; the larger the reaction order, the more significant the effect of changes in oxygen concentration on the reaction rate, and its value is usually between 0.5 and 1; the effective reaction surface area is the effective surface area of ​​the coal sample participating in the oxidation reaction, including the original pore surface area of ​​the coal sample and the fresh surface area generated by crushing; this parameter gradually decreases during the oxidation process due to surface passivation; the gas constant is a universal gas constant in physical chemistry, used to convert activation energy units to temperature units.

[0034] Understandably, in actual coal mining processes, it is necessary to obtain data such as the grinding power of the coal mining machine, the total carbon monoxide concentration in the roadway, the coal temperature, the oxygen concentration, and the ventilation volume. By substituting the grinding power and ventilation volume into the aforementioned formula for calculating the carbon monoxide concentration generated by mechanical crushing, and then calculating the carbon monoxide concentration generated underground by spontaneous combustion oxidation based on the total carbon monoxide concentration and the background carbon monoxide concentration, this method achieves real-time separation of carbon monoxide from both mechanical crushing and spontaneous combustion oxidation during coal mining. This provides an accurate oxidation signal for spontaneous combustion early warning, avoiding false alarms caused by carbon monoxide from normal coal cutting.

[0035] Please refer to Figure 2This invention discloses a method for simulating and monitoring carbon monoxide concentration in coal spontaneous combustion, applied to a coal spontaneous combustion carbon monoxide concentration simulation and monitoring experimental system. The method includes the following steps: Step 200: Place the coal sample into a sealed cylinder; Step 210: Apply simulated mechanical crushing stress to the coal sample inside the cylinder, and monitor the grinding power during the crushing process in real time; Step 220: After evacuating the cylinder, introduce a preset gas to maintain the atmosphere conditions inside the cylinder during coal mining. Step 230: Control the temperature inside the cylinder to the temperature conditions during coal mining; Step 240: Real-time collection of total carbon monoxide concentration inside the cylinder; Step 250: Determine the carbon monoxide concentration generated by mechanical crushing based on the grinding power, and obtain the carbon monoxide concentration generated by spontaneous combustion oxidation based on the total carbon monoxide concentration and the carbon monoxide concentration generated by mechanical crushing.

[0036] It is understood that the method embodiments and system embodiments provided by the present invention are based on the same inventive concept and have the same beneficial effects. The beneficial effects of the method embodiments will not be elaborated here.

[0037] In summary, this invention provides a simulated monitoring system and method for carbon monoxide concentration in coal spontaneous combustion. By constructing a simulated monitoring system comprising a sealed cylinder, a stress loading component, an atmosphere control component, a temperature control component, a gas sampling component, and a data analysis component, the system can simulate the real environment of mechanical crushing and spontaneous combustion oxidation during coal mining. The stress loading component monitors the grinding power in real time, and combined with the total carbon monoxide concentration collected by the gas sampling component, the data analysis component can quantitatively separate the carbon monoxide concentration generated by mechanical crushing and the carbon monoxide concentration generated by spontaneous combustion oxidation, solving the problem of indistinguishability between the two sources of carbon monoxide in existing technologies. Based on the spontaneous combustion oxidation carbon monoxide concentration obtained by this system, accurate oxidation signals can be provided for early warning of spontaneous combustion in coal mines, effectively avoiding false alarms caused by carbon monoxide from normal coal cutting, and improving the accuracy and reliability of early warning.

[0038] An iterative formula with memory effect is introduced to calculate the carbon monoxide concentration generated by mechanical breakage, fully considering the decay process of carbon monoxide continuously released from the fresh surface after breakage, making the estimation of the contribution of mechanical breakage more accurate. A subtraction formula is used to subtract the contribution of mechanical breakage and the background concentration from the total carbon monoxide concentration, achieving quantitative separation of carbon monoxide from the two sources. By comparing the actual spontaneous combustion carbon monoxide concentration with the theoretical value multiplied by a safety factor to obtain a warning threshold, an adaptive alarm based on dynamic temperature adjustment is implemented. This avoids the problems of false alarms at high temperatures and missed alarms at low temperatures caused by fixed thresholds, significantly improving the accuracy and adaptability of spontaneous combustion warnings.

[0039] It should be noted that, in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0040] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A simulated monitoring system for carbon monoxide concentration during spontaneous combustion of coal, characterized in that, include: A sealed cylinder used to hold coal samples; A stress loading component, connected to the cylinder, is used to apply simulated mechanical crushing stress to the coal sample inside the cylinder, and to monitor the grinding power in real time during the crushing process. An atmosphere control component, connected to the cylinder, is used to perform vacuuming and gas introduction into the cylinder to maintain the atmosphere conditions required for coal mining. A temperature control component, connected to the cylinder, is used to control the temperature inside the cylinder to the temperature conditions during coal mining. A gas sampling component, connected to the cylinder, is used to collect the total carbon monoxide concentration inside the cylinder in real time; The data analysis component is connected to the stress loading component, atmosphere control component, temperature control component and gas sampling component respectively, and is used to determine the concentration of carbon monoxide generated by mechanical crushing based on the grinding power, and to obtain the concentration of carbon monoxide generated by spontaneous combustion oxidation based on the concentration of carbon monoxide generated and the total concentration of carbon monoxide.

2. The system according to claim 1, characterized in that, The stress loading component includes: A planetary ball mill, located outside the cylinder, is used to apply controllable mechanical crushing energy to the coal sample inside the cylinder; A vibration mechanism, located outside the cylinder, is used to apply shear force to the coal sample; A power sensor is used to monitor the grinding power in real time during the crushing process; Torque sensor, used to monitor torque in real time during the crushing process; A speed sensor is used to monitor the rotational speed during the crushing process in real time.

3. The system according to claim 1, characterized in that, The atmosphere control component includes: A vacuum pump, connected to the cylinder via a pipeline, is used to evacuate the cylinder. A gas source, connected to the cylinder body via a pipeline, is used to introduce a preset gas into the cylinder body; An airflow controller is installed on the pipeline between the gas source and the cylinder to control the on / off state and magnitude of the gas flow inside the cylinder.

4. The system according to claim 1, characterized in that, The temperature control component includes: An electric heating jacket is wrapped around the outer wall of the cylinder and is used to heat the cylinder. A thermocouple is installed inside the cylinder to monitor the temperature inside the cylinder in real time. A PID temperature controller is electrically connected to the electric heating jacket and the thermocouple, respectively, and is used to control the heating power of the electric heating jacket according to the temperature feedback from the thermocouple, so as to maintain the temperature inside the cylinder at the temperature conditions during coal mining.

5. The system according to claim 1, characterized in that, The gas sampling component includes: An automatic sampling valve, connected to the cylinder, is used to collect gas inside the cylinder; A gas chromatograph, connected to the automatic sampling valve, is used to analyze the composition and concentration of each component of the gas inside the cylinder; An infrared CO analyzer, connected to the automatic sampling valve, is used to continuously monitor the total concentration of carbon monoxide in the gas.

6. The system according to claim 1, characterized in that, The concentration of carbon monoxide generated due to mechanical crushing is calculated using the following formula: for The concentration of carbon monoxide produced by constant mechanical crushing. for Grinding power at all times This represents the CO production per unit of energy input. Let be the decay time constant of carbon monoxide release after mechanical crushing. The volume of gas introduced into the cylinder per unit time. This is the preset reference gas flow rate.

7. The system according to claim 6, characterized in that, The concentration of carbon monoxide generated by the spontaneous combustion oxidation is calculated using the following formula: The concentration of carbon monoxide produced by spontaneous combustion oxidation. This represents the total concentration of carbon monoxide. This refers to the carbon monoxide concentration produced by mechanical crushing. The background carbon monoxide concentration is used as a reference.

8. The system according to claim 7, characterized in that, The data analysis component is also used for: Based on the real-time temperature value inside the cylinder, the theoretical spontaneous combustion carbon monoxide concentration corresponding to the real-time temperature value is obtained. The product of the theoretical spontaneous combustion carbon monoxide concentration and the safety factor is calculated and used as the warning threshold. An alarm signal is issued when the concentration of carbon monoxide produced by the spontaneous combustion exceeds the warning threshold.

9. The system according to claim 8, characterized in that, The theoretical carbon monoxide concentration for spontaneous combustion is calculated using the following formula: The theoretical concentration of carbon monoxide for spontaneous combustion. This represents the coal sample temperature corresponding to the real-time temperature value. This represents the volume fraction of oxygen. The fitting factor for the oxidation experiment. To fit the activation energy in the oxidation experiment, n The reaction order is... To effectively reflect specific surface area, is the gas constant.

10. A method for simulating and monitoring carbon monoxide concentration during spontaneous combustion of coal, characterized in that, Applied to the system according to any one of claims 1-9, the method comprises: Place the coal sample inside a sealed cylinder; The mechanical crushing stress simulating that during coal mining is applied to the coal sample inside the cylinder, and the grinding power during the crushing process is monitored in real time. After the cylinder is evacuated, a preset gas is introduced to maintain the atmosphere conditions inside the cylinder during coal mining. The temperature inside the cylinder is controlled to the temperature conditions during coal mining. Real-time monitoring of the total carbon monoxide concentration inside the cylinder; The concentration of carbon monoxide generated by mechanical crushing is determined based on the grinding power, and the concentration of carbon monoxide generated by spontaneous combustion oxidation is obtained based on the total concentration of carbon monoxide and the concentration of carbon monoxide generated by mechanical crushing.

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