Gas accumulation and coal spontaneous combustion cooperative prevention and control method and system for coal mine goaf

Abstract

The present application provides a method and system for the coordinated prevention and control of gas accumulation and coal spontaneous combustion in a coal mine goaf, and relates to the technical field of mine safety and disaster prevention and control; the present application obtains an electronic distribution map of a target coal mine goaf and divides the goaf analysis area, collects state monitoring data, prevention and control operation data and historical benchmark data; calculates the gas accumulation retention coefficient and the residual coal oxygen supply self-heating coefficient respectively, obtains the gas accumulation evaluation result and the coal spontaneous combustion evaluation result; combines the risk area spatial relationship, the extraction negative pressure change and the oxygen supply response to calculate the coordinated prevention and control conflict coefficient; determines the coordinated control, the gas accumulation dominant, the coal spontaneous combustion dominant, the composite coordination or the coordinated conflict state according to the comprehensive evaluation result, and adjusts the gas extraction negative pressure and the inert gas injection flow rate, iteratively updates based on the adjusted monitoring result, and realizes the coordinated prevention and control of the gas accumulation and the coal spontaneous combustion risk in the goaf.

Description

Technical Field

[0001] This invention relates to the field of mine safety and disaster prevention technology, specifically to a method and system for the coordinated prevention and control of gas accumulation and spontaneous combustion of coal in coal mine goaf areas. Background Technology

[0002] The goaf formed after the coal face is mined out has a complex internal spatial structure. Residual coal, collapsed rock, and fracture channels together create a non-uniform gas migration environment. Affected by continuous gas outbursts, ventilation leaks, and changes in extraction conditions, some areas are prone to obstructed gas migration and localized accumulation. Under continuous oxygen supply, residual coal in the goaf undergoes low-temperature oxidation, accompanied by oxygen consumption, carbon monoxide generation, and temperature increases. Further development poses a risk of spontaneous combustion. Therefore, gas accumulation and spontaneous combustion coexist and influence each other within the same goaf.

[0003] Current methods for controlling gas in goaf areas typically involve adjusting the negative pressure of gas extraction based on parameters such as gas concentration and extraction flow rate. Meanwhile, coal spontaneous combustion prevention mainly relies on measures like inerting and oxygen reduction based on oxygen concentration, carbon monoxide concentration, and temperature. These two control processes are usually conducted separately, lacking a comprehensive assessment of the spatial relationships between different risk areas and the mutual influence of their control effects. In particular, increasing the negative pressure of gas extraction alters the pressure distribution and gas flow patterns within the goaf, changing the oxygen supply conditions in some residual coal areas. If extraction is increased solely based on the degree of gas accumulation, it will negatively impact coal spontaneous combustion prevention. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for the coordinated prevention and control of gas accumulation and spontaneous combustion of coal in coal mine goaf areas, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for the coordinated prevention and control of gas accumulation and spontaneous combustion of coal in coal mine goaf areas, comprising the following specific steps: Step 1: Obtain the electronic distribution map of the goaf of the target coal mine, divide the goaf of the target coal mine into several goaf analysis areas, collect goaf status monitoring data, prevention and control operation data and historical benchmark data of each goaf analysis area, and obtain preprocessed goaf status monitoring data and prevention and control operation data after preprocessing. Step 2: Based on historical benchmark data, preprocessed goaf status monitoring data, and prevention and control operation data, calculate the gas accumulation retention coefficient of each goaf analysis area, and obtain the gas accumulation assessment results after evaluation. Step 3: Based on historical benchmark data and pre-processed goaf status monitoring data, calculate the oxygen supply self-heating coefficient of residual coal in each goaf analysis area, and obtain the coal spontaneous combustion assessment results after evaluation. Step 4: Based on the electronic distribution map of the goaf of the target coal mine, the gas accumulation assessment results, and the coal spontaneous combustion assessment results, combined with the pre-processed goaf status monitoring data and prevention and control operation data, calculate and obtain the collaborative prevention and control conflict coefficient. Step 5: Based on the gas accumulation assessment results, coal spontaneous combustion assessment results, and collaborative prevention and control conflict coefficient, obtain the collaborative prevention and control assessment results for each goaf analysis area; based on the collaborative prevention and control assessment results and prevention and control operation data, adjust the gas extraction negative pressure and inert injection flow rate, and iteratively update the goaf status monitoring data and prevention and control operation data obtained after adjustment.

[0006] Further, step one includes: S11. Using GIS technology and target coal mine surveying data, obtain an electronic distribution map of the target coal mine goaf, including the working face spatial boundary, working face advance direction, working face dip direction, goaf monitoring location, gas drainage branches and their connected drainage borehole groups, and inert injection branch location; use the gas drainage effective influence range determination method to obtain the effective influence radius of each drainage borehole group; combine the goaf monitoring location and the effective influence range of each drainage borehole group, and use the spatial grid division method to divide the target coal mine goaf into several goaf analysis areas; obtain the spatial coordinates of the geometric center of each goaf analysis area, and determine the gas drainage branches, drainage borehole groups, and inert injection branches corresponding to each goaf analysis area; S12. Monitor the gas and temperature status of any goaf analysis area in real time according to a fixed sampling cycle, and collect goaf status monitoring data, including gas concentration, oxygen concentration, carbon monoxide concentration and temperature. S13. Monitor the gas extraction process and inertia injection process of any goaf analysis area in real time according to a fixed sampling period, and collect prevention and control operation data, including the extraction flow rate, extraction negative pressure and current inertia injection flow rate of the corresponding gas extraction branch. S14. Obtain historical monitoring records and historical prevention and control operation records during the historical stable operation period of the target coal mine goaf area, and collect historical benchmark data, including historical gas concentration, historical oxygen concentration, historical carbon monoxide concentration, historical temperature, historical drainage flow rate and historical drainage negative pressure. S15. Perform time correspondence and abnormal data processing on the goaf status monitoring data and prevention and control operation data according to the sampling time to obtain preprocessed goaf status monitoring data and prevention and control operation data.

[0007] Furthermore, step two includes: S21. Based on historical benchmark data, pre-processed goaf status monitoring data, and prevention and control operation data, determine the historical stable operating lower limit and historical stable operating upper limit of gas concentration, extraction flow rate, and extraction negative pressure, respectively. Based on the historical stable operating lower limit and historical stable operating upper limit corresponding to each parameter, perform dimensionless normalization processing on the gas concentration, extraction flow rate, and extraction negative pressure of any goaf analysis area in the current sampling period and the previous sampling period to obtain the normalized gas concentration, normalized gas concentration, normalized extraction flow rate, normalized extraction negative pressure, and normalized extraction negative pressure of the current sampling period and the previous sampling period. S22. Based on the normalized gas concentration of the current sampling period and the previous sampling period in any goaf analysis area, calculate and obtain the positive change in gas concentration. S23. Calculate and obtain the extraction transfer effectiveness based on the normalized extraction flow rate and normalized extraction negative pressure of the current sampling period.

[0008] Furthermore, step two also includes: S24. Based on the normalized gas concentration, positive change in gas concentration, and extraction and transfer effectiveness of the current sampling period, calculate the gas accumulation and retention coefficient of any goaf analysis area. S25. By setting a preset gas accumulation assessment threshold and comparing it with the gas accumulation retention coefficient of any goaf analysis area, the gas accumulation assessment results are obtained, including: When the gas accumulation retention coefficient is less than the gas accumulation assessment threshold, the current goaf analysis area is determined to be a gas accumulation controlled area; When the gas accumulation retention coefficient is greater than or equal to the gas accumulation assessment threshold, the current goaf analysis area is identified as a gas accumulation risk area.

[0009] Furthermore, step three includes: S31. Based on historical benchmark data and pre-processed goaf status monitoring data, determine the historical stable operating lower limit and historical stable operating upper limit for carbon monoxide concentration, temperature, and oxygen concentration, respectively. Based on the historical stable operating lower limit and historical stable operating upper limit corresponding to each parameter, perform dimensionless normalization processing on the carbon monoxide concentration, temperature, and oxygen concentration of any goaf analysis area in the current sampling period and the previous sampling period to obtain the normalized carbon monoxide concentration in the current sampling period and the normalized carbon monoxide concentration in the previous sampling period, the normalized temperature in the current sampling period and the normalized temperature in the previous sampling period, and the normalized oxygen concentration in the current sampling period and the normalized oxygen concentration in the previous sampling period. S32. Based on the normalized carbon monoxide concentration of the current sampling period and the previous sampling period of any goaf analysis area, calculate and obtain the positive change in carbon monoxide concentration. S33. Based on the normalized temperature of the current sampling period and the previous sampling period of any goaf analysis area, calculate and obtain the positive temperature change. S34. Based on the normalized oxygen concentration of the current sampling period and the previous sampling period in any goaf analysis area, calculate and obtain the change in oxygen consumption.

[0010] Furthermore, step three also includes: S35. Based on the positive changes in carbon monoxide concentration, temperature, and oxygen consumption, calculate the self-heating coefficient of residual coal oxygen supply in any goaf analysis area. S36. By setting a preset coal spontaneous combustion assessment threshold and comparing it with the oxygen supply autoheating coefficient of residual coal in any goaf analysis area, the coal spontaneous combustion assessment results are obtained, including: When the oxygen supply self-heating coefficient of the residual coal is less than the coal spontaneous combustion assessment threshold, the current goaf analysis area is determined as a coal spontaneous combustion controlled area. When the oxygen supply self-heating coefficient of the residual coal is greater than or equal to the coal spontaneous combustion assessment threshold, the current goaf analysis area is identified as a coal spontaneous combustion risk area.

[0011] Furthermore, step four includes: S41. Based on the gas accumulation assessment results and coal spontaneous combustion assessment results, obtain the distribution of gas accumulation risk areas and coal spontaneous combustion risk areas in each goaf analysis area; take the goaf analysis area corresponding to any gas accumulation risk area as the first correlation analysis area; based on the spatial coordinates of the geometric center of each goaf analysis area, use the spatial Euclidean distance calculation method to obtain the spatial distance between the first correlation analysis area and the goaf analysis areas corresponding to each coal spontaneous combustion risk area; take the goaf analysis area corresponding to the coal spontaneous combustion risk area with the smallest spatial distance as the second correlation analysis area, and obtain the spatial distance between the first correlation analysis area and the second correlation analysis area; S42. Based on the spatial distance between the first correlation analysis region and the second correlation analysis region, and the effective influence radius of the gas drainage branch connected to the drainage borehole group in the first correlation analysis region, calculate and obtain the spatial correlation degree. S43. Based on the normalized extraction negative pressure of the gas extraction branch corresponding to the first correlation analysis region in the current sampling period and the previous sampling period, calculate the positive change in extraction negative pressure. S44. Based on the oxygen concentration of the current sampling period and the previous sampling period in the second correlation analysis region, perform dimensionless normalization processing to obtain the normalized oxygen concentration of the current sampling period and the previous sampling period, and calculate the positive change in oxygen concentration.

[0012] Furthermore, step four also includes: S45. Based on the positive change in negative pressure and the positive change in oxygen concentration, calculate the oxygen supply response degree induced by extraction between the first correlation analysis region and the second correlation analysis region. S46. Based on the carbon monoxide concentration, temperature, and oxygen concentration of the current sampling period and the previous sampling period in the second correlation analysis area, the residual coal oxygen supply self-heating coefficient of the second correlation analysis area is obtained by using dimensionless normalization, change extraction, and multi-parameter equal weight fusion calculation methods. Based on the gas accumulation and retention coefficient of each goaf analysis area, the gas accumulation and retention coefficient corresponding to the first correlation analysis area is obtained. Combined with the residual coal oxygen supply self-heating coefficient, spatial correlation degree, and extraction-induced oxygen supply response degree of the second correlation analysis area, the collaborative prevention and control conflict coefficient is calculated.

[0013] Furthermore, step five includes: S51. By setting a pre-defined collaborative conflict assessment threshold and combining it with the gas accumulation assessment results, coal spontaneous combustion assessment results, and collaborative prevention and control conflict coefficient, a comprehensive analysis is conducted to obtain the collaborative prevention and control assessment results for each goaf analysis area, including: When the collaborative prevention and control conflict coefficients corresponding to the first and second association analysis regions are greater than or equal to the collaborative conflict assessment threshold, the first and second association analysis regions will be preferentially identified as collaborative conflict regions. For the first and second association analysis regions that are not identified as collaborative conflict regions and whose corresponding collaborative prevention and control conflict coefficients are less than the collaborative conflict assessment threshold, the first and second association analysis regions are identified as composite collaborative regions. For goaf analysis areas that are not identified as collaborative conflict areas or composite collaborative areas, when any goaf analysis area is simultaneously a gas accumulation controlled area and a coal spontaneous combustion controlled area, the current goaf analysis area will be identified as a collaboratively controlled area. For goaf analysis areas that are not identified as collaborative conflict areas or complex collaborative areas, if any goaf analysis area is a gas accumulation risk area and a coal spontaneous combustion controlled area, the current goaf analysis area will be identified as a gas accumulation dominant area. For goaf analysis areas that are not identified as collaborative conflict areas or complex collaborative areas, if any goaf analysis area is a gas accumulation controlled area and a coal spontaneous combustion risk area, the current goaf analysis area will be identified as a coal spontaneous combustion dominant area. S52. Based on the collaborative prevention and control assessment results of each goaf analysis area, determine the corresponding collaborative prevention and control strategies for gas drainage and inert gas injection, including: For the coordinated controlled area, maintain the current negative pressure of the corresponding gas extraction branch and the current inert flow rate of the corresponding inert injection branch; For areas dominated by gas accumulation, the negative pressure of the corresponding gas extraction branch will be increased by 5% to 15% based on the current negative pressure, while maintaining the current inert injection flow rate of the corresponding inert injection branch. For areas dominated by spontaneous combustion of coal, the negative pressure of the corresponding gas extraction branch will be reduced by 5% to 10% based on the current negative pressure, and the inert injection flow rate of the corresponding inert injection branch will be increased by 10% to 30% based on the current inert injection flow rate. For the composite synergistic region, the negative pressure of the gas drainage branch corresponding to the first correlation analysis region will be increased by 3% to 8% based on the current negative pressure, and the inert flow rate of the inert injection branch corresponding to the second correlation analysis region will be increased by 10% to 20% based on the current inert flow rate. For areas of coordinated conflict, maintain the current negative pressure of the gas drainage branch corresponding to the first correlation analysis area, and increase the inert flow rate of the inert injection branch corresponding to the second correlation analysis area by 20% to 30% based on the current inert flow rate; S53. After adjusting the gas extraction negative pressure and inertia injection flow rate, re-acquire the goaf status monitoring data and prevention and control operation data according to the fixed sampling cycle, and re-analyze the gas accumulation status and the residual coal oxygen supply self-heating status. When there are both gas accumulation risk areas and coal spontaneous combustion risk areas, re-analyze the collaborative prevention and control conflict, and re-analyze the comprehensive analysis based on the updated gas accumulation assessment results, coal spontaneous combustion assessment results and collaborative prevention and control conflict coefficient. Iteratively update the gas extraction negative pressure and inertia injection flow rate to achieve continuous optimization of collaborative prevention and control parameters.

[0014] Furthermore, a coordinated prevention and control system for gas accumulation and spontaneous combustion of coal in coal mine goaf areas includes: The goaf data acquisition and preprocessing module is used to obtain an electronic distribution map of the goaf of the target coal mine, divide the goaf of the target coal mine into several goaf analysis areas, collect goaf status monitoring data, prevention and control operation data and historical benchmark data of each goaf analysis area, and obtain preprocessed goaf status monitoring data and prevention and control operation data after preprocessing. The gas accumulation assessment module is used to calculate the gas accumulation retention coefficient of each goaf analysis area based on historical benchmark data, preprocessed goaf status monitoring data and prevention and control operation data, and obtain the gas accumulation assessment results after assessment. The residual coal self-heating assessment module is used to calculate the oxygen supply self-heating coefficient of residual coal in each goaf analysis area based on historical benchmark data and pre-processed goaf status monitoring data, and obtain the coal self-ignition assessment results after assessment. The collaborative prevention and control conflict analysis module is used to calculate and obtain the collaborative prevention and control conflict coefficient based on the electronic distribution map of the goaf of the target coal mine, the gas accumulation assessment results and the coal spontaneous combustion assessment results, combined with the pre-processed goaf status monitoring data and prevention and control operation data. The collaborative prevention and control strategy optimization module is used to obtain the collaborative prevention and control assessment results of each goaf analysis area based on the gas accumulation assessment results, coal spontaneous combustion assessment results, and collaborative prevention and control conflict coefficient; based on the collaborative prevention and control assessment results and prevention and control operation data, the negative pressure of gas extraction and the inert injection flow rate are adjusted, and the goaf status monitoring data and prevention and control operation data are iteratively updated based on the adjusted goaf status monitoring data and prevention and control operation data.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention constructs a gas accumulation retention coefficient and a residual coal oxygen supply self-heating coefficient to quantitatively characterize the gas concentration growth, extraction status, carbon monoxide generation, temperature rise, and oxygen consumption characteristics of different analysis areas in the goaf. Compared with judging based solely on a single gas concentration, oxygen concentration, or temperature threshold, this invention can more accurately distinguish between areas of continuous gas accumulation and areas of residual coal oxidation self-heating, improving the pertinence of identifying complex disaster states in the goaf and providing a more accurate risk identification basis for mine safety and disaster prevention.

[0016] This invention also combines the spatial distance between the gas accumulation risk area and the coal spontaneous combustion risk area, the effective influence range of gas drainage, and the oxygen supply response of the coal spontaneous combustion risk area during the increase of drainage negative pressure to construct a collaborative prevention and control conflict coefficient. This coefficient is used to determine whether enhanced gas drainage has an additional oxygen supply effect on the adjacent coal spontaneous combustion risk area, thereby avoiding the exacerbation of residual coal oxidation and self-heating by simply increasing the drainage negative pressure. This enables a quantitative analysis of the mutual constraint relationship between gas control and coal spontaneous combustion prevention and control.

[0017] This invention also conducts a comprehensive evaluation based on the results of gas accumulation assessment, coal spontaneous combustion assessment, and collaborative prevention and control conflict coefficient. For different states such as collaborative control, gas accumulation-dominated, coal spontaneous combustion-dominated, composite collaboration, and collaborative conflict, it implements differentiated percentage adjustments to the negative pressure of gas extraction and the inertia injection flow rate. After completing the parameter adjustments, a new state analysis and comprehensive evaluation are conducted, and the prevention and control parameters are iteratively updated. This forms a closed-loop collaborative prevention and control process for multi-area composite risks in goaf areas, improving the collaborative control capabilities in mine safety and disaster prevention. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall method steps of the present invention; Figure 2 This is a schematic diagram of the overall system flow of the present invention. Detailed Implementation

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0020] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0021] Example 1: Please see Figure 1 This invention provides a technical solution: a method for the coordinated prevention and control of gas accumulation and spontaneous combustion of coal in coal mine goaf areas, the specific steps of which include: Step 1: Obtain the electronic distribution map of the goaf of the target coal mine, divide the goaf of the target coal mine into several goaf analysis areas, collect goaf status monitoring data, prevention and control operation data and historical benchmark data of each goaf analysis area, and obtain preprocessed goaf status monitoring data and prevention and control operation data after preprocessing. Step 2: Based on historical benchmark data, preprocessed goaf status monitoring data, and prevention and control operation data, calculate the gas accumulation retention coefficient of each goaf analysis area, and obtain the gas accumulation assessment results after evaluation. Step 3: Based on historical benchmark data and pre-processed goaf status monitoring data, calculate the oxygen supply self-heating coefficient of residual coal in each goaf analysis area, and obtain the coal spontaneous combustion assessment results after evaluation. Step 4: Based on the electronic distribution map of the goaf of the target coal mine, the gas accumulation assessment results, and the coal spontaneous combustion assessment results, combined with the pre-processed goaf status monitoring data and prevention and control operation data, calculate and obtain the collaborative prevention and control conflict coefficient. Step 5: Based on the gas accumulation assessment results, coal spontaneous combustion assessment results, and collaborative prevention and control conflict coefficient, obtain the collaborative prevention and control assessment results for each goaf analysis area; based on the collaborative prevention and control assessment results and prevention and control operation data, adjust the gas extraction negative pressure and inert injection flow rate, and iteratively update the goaf status monitoring data and prevention and control operation data obtained after adjustment.

[0022] In this embodiment, the goaf is divided into regions, and the gas accumulation state, the oxygen supply and self-heating state of residual coal, and the synergistic prevention and control conflict between the two are analyzed layer by layer. Based on the comprehensive evaluation results, the negative pressure of gas drainage and the inert flow rate are adjusted, so that gas control and coal spontaneous combustion prevention and control are transformed from independent single-hazard control to synergistic regulation of multiple regional composite risks in the same goaf, thereby reducing the possibility that simply enhancing gas drainage will have an adverse effect on coal spontaneous combustion prevention and control.

[0023] Example 2 Please see Figure 1 In this embodiment, as explained in Embodiment 1, specifically, step one includes: S11. Using GIS technology and target coal mine mapping data, obtain an electronic distribution map of the target coal mine's goaf, including the working face spatial boundary, working face advance direction, working face dip direction, goaf monitoring location, gas drainage branches and their connected drainage borehole groups, and inertia injection branch location; use the gas drainage effective influence range determination method to obtain the effective influence radius of each drainage borehole group; based on the working face spatial boundary, using the working face advance direction and working face dip direction as the dividing direction, and combining the goaf monitoring location and the effective influence range of each drainage borehole group, use the spatial grid division method to divide the target coal mine's goaf into several goaf analysis areas, and mark each goaf analysis area as... , ... Where n represents the number of goaf analysis areas; obtain the spatial coordinates of the geometric center of each goaf analysis area, and determine the gas drainage branch, drainage borehole group, and inertia injection branch corresponding to each goaf analysis area based on the positions of the gas drainage branch, drainage borehole group, and inertia injection branch in the goaf electronic distribution map; denot the effective influence radius of the drainage borehole group connected to the gas drainage branch corresponding to the i-th goaf analysis area as . ; Specifically, this involves: retrieving surveying data, mining engineering plan data, and gas drainage layout data of the target coal mine; obtaining the working face spatial boundaries, working face advance direction, working face dip direction, goaf monitoring locations, gas drainage branches and their connected drainage borehole groups, and inertia injection branch locations; and using GIS technology to establish an electronic distribution map of the target coal mine goaf; based on the connection relationship between each gas drainage branch and the drainage borehole group, employing existing and known methods for determining the effective influence range of gas drainage, and considering different distances around the drainage borehole group... The gas drainage response at a given location is determined to be the furthest distance from which an effective drainage response can be generated, and this furthest distance is taken as the effective influence radius of the corresponding drainage borehole group. According to the regional boundary of the goaf analysis area, the geometric center of each goaf analysis area is obtained using the GIS geometric center determination method, and the spatial coordinates of the corresponding geometric center are read. Based on the spatial positional relationship between each goaf analysis area and the gas drainage branch, drainage borehole group, and inertia injection branch, the gas drainage branch, drainage borehole group, and inertia injection branch corresponding to each goaf analysis area are determined. S12. Monitor the gas and temperature status of the i-th goaf analysis area in real time according to a fixed sampling period, and collect goaf status monitoring data, including the gas concentration, oxygen concentration, carbon monoxide concentration and temperature of the i-th goaf analysis area. Specifically, gas sampling tubes and temperature detection devices are deployed at monitoring locations corresponding to each goaf analysis area. The sampling end of the gas sampling tube is set at the corresponding goaf analysis area, and the gas sampling tube is connected to the gas detection device. Goaf gas is extracted according to a fixed sampling period. The volume fractions of methane, oxygen, and carbon monoxide in the extracted gas are detected using methane, oxygen, and carbon monoxide concentration detection methods, respectively, to obtain the methane, oxygen, and carbon monoxide concentrations of the i-th goaf analysis area. The temperature of the i-th goaf analysis area is obtained using temperature detection methods through thermocouples, temperature sensors, or distributed fiber optic temperature measurement lines set at the corresponding monitoring locations. The methane, oxygen, carbon monoxide, and temperature obtained at the same sampling time are correlated according to the corresponding goaf analysis area to obtain goaf status monitoring data. S13. Monitor the gas extraction process and inertia injection process corresponding to the i-th goaf analysis area in real time according to a fixed sampling period, and collect prevention and control operation data, including the extraction flow rate, extraction negative pressure and current inertia injection flow rate of the gas extraction branch corresponding to the i-th goaf analysis area. Specifically, gas flow and pressure detection devices are installed on the extraction pipelines of each gas extraction branch. Using pipeline gas flow and negative pressure detection methods, the extraction flow and negative pressure of the corresponding gas extraction branch are obtained according to a fixed sampling period. Gas flow detection devices are installed on the delivery pipelines of each inertia injection branch. The current inertia injection flow of the corresponding inertia injection branch is obtained using pipeline gas flow detection methods. Based on the spatial correspondence between each goaf analysis area and the gas extraction and inertia injection branches, the extraction flow, negative pressure, and current inertia injection flow are correlated with the corresponding goaf analysis area to obtain prevention and control operation data. S14. Obtain historical monitoring records and historical prevention and control operation records during the historical stable operation period of the target coal mine goaf area, and collect historical benchmark data, including historical gas concentration, historical oxygen concentration, historical carbon monoxide concentration, historical temperature, historical drainage flow rate and historical drainage negative pressure. Specifically, the process involves: retrieving historical monitoring records and historical prevention and control operation records of the target coal mine's goaf area; selecting historical stable operating periods where gas drainage is continuously operating, detection data is continuously valid, and no abnormal gas accumulation or coal spontaneous combustion development has occurred; and organizing the gas concentration, oxygen concentration, carbon monoxide concentration, temperature, drainage flow rate, and drainage negative pressure recorded during the historical stable operating periods according to the goaf analysis area and sampling time to obtain historical gas concentration, historical oxygen concentration, historical carbon monoxide concentration, historical temperature, historical drainage flow rate, and historical drainage negative pressure, thus forming historical baseline data. S15. Perform time correspondence and abnormal data processing on the goaf status monitoring data and prevention and control operation data according to the sampling time to obtain pre-processed goaf status monitoring data and prevention and control operation data. Specifically, the sampling time corresponding to the status monitoring data and prevention and control operation data of each goaf is read. A unified timestamp method is used to correlate the gas concentration, oxygen concentration, carbon monoxide concentration, temperature, extraction flow rate, extraction negative pressure and current inert injection flow rate within the same sampling period. Data collected beyond the effective range of each detection device is removed, and isolated abnormal data is identified and removed by comparing adjacent continuous sampling data, thus obtaining pre-processed goaf status monitoring data and prevention and control operation data.

[0024] In this embodiment, the goaf is divided into spatial grids by combining the working face spatial boundary, advance direction, dip direction, monitoring location, and effective influence range of the drainage borehole group. The correspondence between each analysis area and the gas drainage branch, drainage borehole group, and inert injection branch is established. At the same time, the status monitoring data and prevention and control operation data are uniformly time-corresponded and abnormal data are processed, so that the subsequent gas risk, spontaneous combustion risk, and prevention and control conflict analysis have clear spatial objects and consistent data time sequence basis, reducing the evaluation deviation caused by the mixing of data from different locations and different sampling times.

[0025] Example 3 Please see Figure 1 In the explanation of Example 2, this embodiment specifically includes the following steps: S21. Based on historical benchmark data, pre-processed goaf status monitoring data, and prevention and control operation data, determine the historical stable operating lower limit and historical stable operating upper limit for gas concentration, extraction flow rate, and extraction negative pressure, respectively. Based on the historical stable operating lower limit and historical stable operating upper limit corresponding to each parameter, perform dimensionless normalization processing on the gas concentration, extraction flow rate, and extraction negative pressure of the i-th goaf analysis area in the current sampling period and the previous sampling period. Calculate the ratio between the difference between the current value of each parameter and the corresponding historical stable operating lower limit, and the difference between the corresponding historical stable operating upper limit and the historical stable operating lower limit, and limit the obtained result to the range of 0 to 1 to obtain the normalized gas concentration of the current sampling period. Normalized gas concentration from the previous sampling period Normalized extraction flow rate Normalized sampling negative pressure of the current sampling period Normalized sampling negative pressure of the previous sampling period ; S22. Normalized gas concentration based on the current sampling period of the analysis area of ​​the i-th goaf. Normalized gas concentration compared to the previous sampling period Calculate and obtain the positive change in gas concentration. The formula is as follows: In the formula, This represents the positive change in gas concentration in the i-th goaf analysis area. It is the positive change in gas concentration when the normalized gas concentration in the current sampling period is not higher than the normalized gas concentration in the previous sampling period. Set to 0; S23, Normalized sampling flow rate based on the current sampling period and the normalized sampling negative pressure of the current sampling period Calculate and obtain the effectiveness of sampling and transfer. The formula is as follows: In the formula, This represents the gas drainage transfer effectiveness of the gas drainage branch corresponding to the i-th goaf analysis area. The larger the value, the more fully the combined state of the gas drainage negative pressure and the actual drainage flow rate of the corresponding gas drainage branch is achieved.

[0026] In this embodiment, the gas concentration, extraction flow rate, and extraction negative pressure are normalized to a unified scale using historical stable operating upper and lower limits. Furthermore, the extraction transfer effectiveness formed by the positive change in gas concentration and the extraction negative pressure and extraction flow rate is extracted. This allows the gas accumulation analysis to not only reflect the current gas concentration level but also simultaneously reflect the trend of continued gas growth and the actual extraction status, providing a more targeted quantitative basis for distinguishing between temporary high concentrations and continuous accumulation.

[0027] Example 4 Please see Figure 1 In the explanation of Embodiment 3, specifically, step two further includes: S24. Normalized gas concentration based on the current sampling period Positive change in gas concentration And the effectiveness of sampling and transmission Calculate the gas accumulation and retention coefficient of the i-th goaf analysis area. The formula is as follows: In the formula, This represents the gas accumulation and retention coefficient of the i-th goaf analysis area. Indicates the degree of insufficient gas extraction transmission in the corresponding gas extraction branch; gas accumulation and retention coefficient. The larger the value, the higher the gas concentration in the current goaf analysis area, the more obvious the continuous growth trend of gas, the weaker the extraction and transmission capacity of the corresponding gas extraction branch, and the higher the degree of continuous gas accumulation. S25. By setting a preset gas accumulation assessment threshold Gth, the gas accumulation retention coefficient of the i-th goaf analysis area is... By comparing the gas accumulation assessment with the gas accumulation assessment threshold Gth, the gas accumulation assessment results for the i-th goaf analysis area are obtained, including: When the gas accumulation retention coefficient When the gas accumulation assessment threshold Gth is reached, it indicates that the current goaf analysis area has not formed the characteristics of continuous gas accumulation, and the current goaf analysis area is judged as a gas accumulation controlled area. When the gas accumulation retention coefficient When the value is greater than or equal to the gas accumulation assessment threshold Gth, it indicates that the current goaf analysis area has formed a combination of gas accumulation characteristics, including increased gas concentration, continuous gas growth, and insufficient extraction and transmission. The current goaf analysis area is then identified as a gas accumulation risk area.

[0028] How to obtain the gas accumulation assessment threshold Gth: The calibration target of the gas accumulation assessment threshold Gth is to determine the critical value of the gas accumulation retention coefficient that can distinguish between "gas accumulation controlled area" and "gas accumulation risk area".

[0029] A standard database of gas accumulation status in the goaf of a target coal mine is constructed, with a sample size of no less than 500 groups, covering different goaf analysis areas, different gas concentration levels, different gas concentration growth states, different extraction flow rates, different extraction negative pressures, and different extraction effectiveness states. Each sample in the database includes gas concentration, extraction flow rate, extraction negative pressure, normalized gas concentration, positive change in gas concentration, extraction transfer effectiveness, gas accumulation retention coefficient, gas concentration change results and extraction operation results for the current sampling period and the previous sampling period.

[0030] Three or more engineering technicians with experience in coal mine gas control, gas extraction and mine safety monitoring will use the "gold standard" to label each group of samples based on the gas concentration level, gas growth, extraction negative pressure, extraction flow rate and subsequent gas accumulation and development, classifying them into controlled gas accumulation and risky gas accumulation.

[0031] According to the calculation method of the gas accumulation retention coefficient of this invention, the gas accumulation retention coefficient of each group of samples was uniformly calculated, and the distribution of gas accumulation retention coefficients corresponding to the controlled gas accumulation samples and the risk gas accumulation samples were statistically analyzed respectively. By constructing ROC curves, the dividing point with the largest Youden index between the two types of samples was used as the gas accumulation assessment threshold Gth.

[0032] Based on the characteristic of the gas accumulation retention coefficient in this invention, which is calculated by equal weighting of normalized gas concentration, positive change in gas concentration, and degree of insufficient extraction and transmission, the preferred gas accumulation assessment threshold Gth is 0.40. When the gas accumulation retention coefficient reaches or exceeds 0.40, it indicates that the current area has shown a combination of accumulation characteristics of high gas level, continuous growth, or insufficient extraction, and the corresponding goaf analysis area is identified as a gas accumulation risk area.

[0033] In this embodiment, a gas accumulation retention coefficient is formed by integrating the current gas level, positive changes in gas concentration, and the degree of insufficient extraction and transmission. The gas accumulation assessment threshold is used to divide the analysis area of ​​each goaf into a gas accumulation controlled area and a gas accumulation risk area. This avoids judging the risk based solely on a single gas concentration threshold, and enables the continuous accumulation characteristics under insufficient extraction capacity to be identified in a timely manner, thereby improving the pertinence of gas accumulation area determination.

[0034] Example 5 Please see Figure 1 In the explanation of Embodiment 4, specifically, step three includes: S31. Based on historical benchmark data and preprocessed goaf condition monitoring data, determine the historical stable operating lower limit and historical stable operating upper limit for carbon monoxide concentration, temperature, and oxygen concentration, respectively. Based on the historical stable operating lower limit and historical stable operating upper limit corresponding to each parameter, perform dimensionless normalization processing on the carbon monoxide concentration, temperature, and oxygen concentration of the i-th goaf analysis area in the current sampling period and the previous sampling period. Calculate the ratio between the difference between the current value of each parameter and the corresponding historical stable operating lower limit, and the difference between the corresponding historical stable operating upper limit and the historical stable operating lower limit. Limit the obtained result to the range of 0 to 1 to obtain the normalized carbon monoxide concentration for the current sampling period. Normalized carbon monoxide concentration compared to the previous sampling period Normalized temperature of the current sampling period Normalized temperature of the previous sampling period and the normalized oxygen concentration for the current sampling period. Normalized oxygen concentration compared to the previous sampling period ; S32. Normalized carbon monoxide concentration based on the current sampling period of the analysis area of ​​the i-th goaf. Normalized carbon monoxide concentration compared to the previous sampling period Calculate the positive change in carbon monoxide concentration. The formula is as follows: In the formula, This represents the positive change in carbon monoxide concentration in the i-th goaf analysis area; when the normalized carbon monoxide concentration of the current sampling period... Normalized carbon monoxide concentration not higher than that of the previous sampling period At that time, the positive change in carbon monoxide concentration The value is 0; the positive change in carbon monoxide concentration. The larger the value, the more obvious the increasing trend of carbon monoxide generation in the current goaf analysis area; S33. Normalized temperature based on the current sampling period of the analysis area of ​​the i-th goaf. Normalized temperature of the previous sampling period Calculate and obtain the positive temperature change. The formula is as follows: In the formula, This represents the positive temperature change in the i-th goaf analysis area; when the normalized temperature of the current sampling period... The normalized temperature was not higher than that of the previous sampling period. At that time, the positive change in temperature A value of 0 represents the positive change in temperature. The larger the value, the more pronounced the continuous warming trend within the current goaf analysis area; S34. Normalized oxygen concentration based on the current sampling period of the i-th goaf analysis area. Normalized oxygen concentration compared to the previous sampling period Calculate and obtain the change in oxygen consumption The formula is as follows: In the formula, This represents the change in oxygen consumption in the i-th goaf analysis area; when the normalized oxygen concentration of the current sampling period... The normalized oxygen concentration was not lower than that of the previous sampling period. Changes in oxygen consumption at that time The value is 0, representing the change in oxygen consumption. The larger the value, the more pronounced the continuous oxygen consumption trend within the current goaf analysis area.

[0035] In this embodiment, by extracting the three directional change features of carbon monoxide concentration increase, temperature increase and oxygen consumption respectively, the analysis of residual coal oxidation autothermal can simultaneously consider the three interrelated process features of gas production, heat release and oxygen consumption. Compared with using only temperature or carbon monoxide concentration for single parameter judgment, it is more conducive to identifying areas in the goaf where residual coal is in a state of continuous oxidation autothermal development.

[0036] Example 6 Please see Figure 1 In the explanation of Example 5, specifically, step three further includes: S35, Based on the positive change in carbon monoxide concentration Positive temperature change and changes in oxygen consumption Calculate the oxygen supply autoheat coefficient of the residual coal in the i-th goaf analysis area. The formula is as follows: In the formula, Represents the self-heating coefficient of oxygen supply from residual coal in the i-th goaf analysis area; self-heating coefficient of oxygen supply from residual coal The larger the value, the more obvious the synergistic changes in carbon monoxide generation, temperature rise, and oxygen consumption within the current goaf analysis area, and the higher the degree of autothermal development of residual coal oxidation. S36. By setting the coal spontaneous combustion assessment threshold Fth, and setting the oxygen supply self-heating coefficient of the residual coal in the i-th goaf analysis area. By comparing and analyzing the results with the coal spontaneous combustion assessment threshold Fth, the coal spontaneous combustion assessment results for the i-th goaf analysis area are obtained, including: When the self-heating coefficient of the residual coal for oxygen supply When the coal spontaneous combustion assessment threshold Fth is reached, it indicates that the current goaf analysis area has not formed the combined self-heating characteristics of continuous carbon monoxide generation, continuous temperature increase and continuous oxygen consumption, and the current goaf analysis area is judged as a coal spontaneous combustion controlled area. When the self-heating coefficient of the residual coal for oxygen supply When the value is greater than or equal to the coal spontaneous combustion assessment threshold Fth, it indicates that the current goaf analysis area has formed a combination of spontaneous heating characteristics, including increased carbon monoxide production, increased temperature, and continuous oxygen consumption, and the current goaf analysis area is identified as a coal spontaneous combustion risk area.

[0037] Method for obtaining the coal spontaneous combustion assessment threshold Fth: The calibration target of the coal spontaneous combustion assessment threshold Fth is to determine the critical value of the residual coal oxygen supply self-heating coefficient that can distinguish between the "coal spontaneous combustion controlled area" and the "coal spontaneous combustion risk area".

[0038] A standard database of the autothermal oxidation state of residual coal in the goaf of a target coal mine was constructed, with a sample size of no less than 500 groups, covering different goaf analysis areas, different carbon monoxide generation states, different temperature change states, different oxygen consumption states, and different degrees of autothermal oxidation development of residual coal. Each sample group includes the carbon monoxide concentration, temperature, and oxygen concentration of the current sampling period and the previous sampling period, as well as the corresponding positive changes in carbon monoxide concentration, temperature, and oxygen consumption, the autothermal oxygen supply coefficient of the residual coal, and the subsequent autothermal oxidation changes of the residual coal.

[0039] Three or more engineering and technical personnel with experience in coal mine spontaneous combustion prevention, goaf gas monitoring, and mine disaster prevention and control will use the "gold standard" to label each group of samples based on the continuous generation of carbon monoxide, the continuous increase in temperature, the continuous consumption of oxygen, and the subsequent self-heating development of residual coal oxidation, classifying them into controlled coal spontaneous combustion and coal spontaneous combustion risk.

[0040] According to the method for calculating the self-heating coefficient of residual coal oxygen supply in this invention, each sample is calculated uniformly, and the statistical distribution analysis of the self-heating coefficient of residual coal oxygen supply in the two types of samples is performed. By constructing ROC curves, the dividing point with the largest Youden index is used as the coal spontaneous combustion assessment threshold Fth.

[0041] Since the self-heating coefficient of residual coal oxygen supply is calculated by weighting the increase in carbon monoxide concentration, temperature increase, and oxygen consumption between two adjacent sampling periods, and these three items are all periodic variations, their normal range is significantly lower than that of the state variables themselves. Therefore, the threshold should not be set too high. The preferred threshold for coal spontaneous combustion assessment, Fth, is 0.15. When the self-heating coefficient of residual coal oxygen supply reaches or exceeds 0.15, it indicates that carbon monoxide generation, temperature increase, and oxygen consumption have formed a relatively obvious combined change characteristic, and the corresponding goaf analysis area is identified as a coal spontaneous combustion risk area.

[0042] In this embodiment, the positive changes in carbon monoxide concentration, temperature, and oxygen consumption are integrated to form the oxygen supply self-heating coefficient of the residual coal. Based on the coal spontaneous combustion assessment threshold, the controlled area of ​​coal spontaneous combustion and the risk area of ​​coal spontaneous combustion are distinguished. This transforms the judgment of coal spontaneous combustion risk from a single abnormal parameter to a joint judgment of multiple oxidation self-heating characteristics, thereby improving the comprehensive characterization ability of the continuous oxidation self-heating state of the residual coal.

[0043] Example 7 Please see Figure 1 In the explanation of Example Six, this embodiment specifically includes step four: S41. Based on the gas accumulation assessment results and coal spontaneous combustion assessment results, obtain the distribution of gas accumulation risk areas and coal spontaneous combustion risk areas in each goaf analysis area; taking the i-th goaf analysis area corresponding to any gas accumulation risk area as the benchmark, based on the spatial coordinates of the geometric center of each goaf analysis area, use the spatial Euclidean distance calculation method to obtain the spatial distance between the i-th goaf analysis area and the goaf analysis areas corresponding to each coal spontaneous combustion risk area, and record the goaf analysis area corresponding to the coal spontaneous combustion risk area with the smallest spatial distance as the j-th goaf analysis area, and record the spatial distance between the i-th goaf analysis area and the j-th goaf analysis area as... Among them, the analysis area of ​​the i-th goaf is taken as the first correlation analysis area, and the analysis area of ​​the j-th goaf is taken as the second correlation analysis area; S42. Based on the spatial distance between the analysis area of ​​the i-th goaf and the analysis area of ​​the j-th goaf. And the effective influence radius of the gas drainage borehole group connected to the gas drainage branch corresponding to the i-th goaf analysis area. Calculate and obtain spatial correlation degree The formula is as follows: In the formula, This represents the spatial correlation between the i-th goaf analysis area and the j-th goaf analysis area. The larger the value, the higher the spatial correlation between the gas extraction range of the j-th goaf analysis area and the i-th goaf analysis area. S43. Based on the normalized negative pressure of the gas drainage branch corresponding to the i-th goaf analysis area during the current sampling period. Normalized sampling negative pressure of the previous sampling period Calculate the positive change in negative pressure during extraction. The formula is as follows: In the formula, This represents the positive change in the negative pressure of the gas drainage branch corresponding to the i-th goaf analysis area. The positive change in negative pressure is defined as follows: when the normalized negative pressure of the current sampling period is not higher than the normalized negative pressure of the previous sampling period. The value is 0; positive change in extraction negative pressure. The larger the value, the greater the increase in negative pressure during gas extraction in the corresponding branch. S44. Based on the oxygen concentration of the current sampling period and the previous sampling period in the analysis area of ​​the j-th goaf, perform dimensionless normalization to obtain the normalized oxygen concentration for the current sampling period. Normalized oxygen concentration compared to the previous sampling period Calculate the positive change in oxygen concentration. The formula is as follows: In the formula, This represents the positive change in oxygen concentration in the j-th goaf analysis area. It is the positive change in oxygen concentration when the normalized oxygen concentration in the current sampling period is not higher than the normalized oxygen concentration in the previous sampling period. The value is 0; the positive change in oxygen concentration. The larger the value, the more significant the increase in oxygen supply in the analysis area of ​​the j-th goaf.

[0044] In this embodiment, the nearest coal spontaneous combustion risk area is determined from the gas accumulation risk area, and the analysis is combined with the spatial distance between the two areas, the effective influence radius of the extraction borehole group, the increase of extraction negative pressure and the increase of oxygen concentration in the coal spontaneous combustion risk area. This allows the subsequent conflict judgment to simultaneously consider the spatial accessibility of gas control and the changes in oxygen supply in the adjacent spontaneous combustion risk area during the extraction enhancement process, avoiding the direct determination of a control conflict between the two based solely on whether the two types of risks exist simultaneously.

[0045] Example 8 Please see Figure 1 In the explanation of Example 7, specifically, step four further includes: S45, Based on the positive change in extraction negative pressure and positive change in oxygen concentration Calculate the extraction-induced oxygen supply response degree between the i-th goaf analysis area and the j-th goaf analysis area. The formula is as follows: In the formula, This represents the extraction-induced oxygen supply response degree between the analysis area of ​​the i-th goaf and the analysis area of ​​the j-th goaf; extraction-induced oxygen supply response degree The larger the value, the more significant the increase in oxygen concentration in the j-th goaf analysis area, as the negative pressure of the gas drainage branch corresponding to the i-th goaf analysis area increases. This indicates a higher degree of additional oxygen supply impact of gas drainage on the j-th goaf analysis area. S46. Based on the carbon monoxide concentration, temperature, and oxygen concentration of the j-th goaf analysis area in the current and previous sampling periods, the residual coal oxygen supply autoheating coefficient of the j-th goaf analysis area is obtained by using dimensionless normalization, change extraction, and multi-parameter weighted fusion calculation methods. Combined with the gas accumulation and retention coefficient of the i-th goaf analysis area Spatial correlation and oxygen supply response induced by extraction Calculate and obtain the collaborative prevention and control conflict coefficient The formula is as follows: In the formula, This represents the collaborative prevention and control conflict coefficient between the i-th and j-th goaf analysis areas; collaborative prevention and control conflict coefficient The larger the value, the higher the risk of spontaneous combustion of coal in the j-th goaf analysis area is when the gas accumulation is reduced by enhancing the gas extraction function corresponding to the i-th goaf analysis area.

[0046] In this embodiment, by correlating the increase in negative pressure during gas extraction with the increase in oxygen concentration in the coal spontaneous combustion risk area, a gas extraction-induced oxygen supply response degree is formed. Furthermore, by combining the gas accumulation state, the oxygen supply self-heating state of the residual coal, and the spatial correlation, the collaborative prevention and control conflict coefficient is calculated. This allows the prevention and control contradiction that was originally difficult to quantify directly—"enhanced gas extraction may form additional oxygen supply to the adjacent residual coal area"—to be quantitatively characterized, providing a clear basis for judging whether gas extraction measures may exacerbate the risk of coal spontaneous combustion.

[0047] Example 9 Please see Figure 1 In the explanation of Embodiment Eight, specifically, step five includes: S51. By setting a pre-defined collaborative conflict assessment threshold Cth, and combining the results of gas accumulation assessment, coal spontaneous combustion assessment, and collaborative prevention and control conflict coefficient, A comprehensive analysis was conducted to obtain the collaborative prevention and control assessment results for each goaf analysis area, including: When the collaborative prevention and control conflict coefficients corresponding to the i-th goaf analysis area and the j-th goaf analysis area are... When the value is greater than or equal to the collaborative conflict assessment threshold Cth, it means that the gas extraction effect corresponding to the i-th goaf analysis area is enhanced, which intensifies the oxidation and self-heating of residual coal in the j-th goaf analysis area. The i-th goaf analysis area and the j-th goaf analysis area are preferentially identified as collaborative conflict areas. For areas not identified as collaborative conflict zones, and with corresponding collaborative prevention and control conflict coefficients The analysis areas of the i-th and j-th goafs, which are related to the collaborative conflict assessment threshold Cth, indicate that both types of risks exist simultaneously, but the additional oxygen supply effect formed by enhanced gas extraction has not reached the level of conflict. The corresponding analysis areas of the i-th and j-th goafs are identified as composite collaborative areas. For goaf analysis areas that are not identified as collaborative conflict areas or composite collaborative areas, when the i-th goaf analysis area is simultaneously a gas accumulation controlled area and a coal spontaneous combustion controlled area, it indicates that the gas accumulation and residual coal oxidation and self-heating in the current goaf analysis area are both under control, and the current goaf analysis area is identified as a collaboratively controlled area. For goaf analysis areas that are not identified as collaborative conflict areas or complex collaborative areas, when the i-th goaf analysis area is a gas accumulation risk area and a coal spontaneous combustion controlled area, it indicates that the main risk of the current goaf analysis area is continuous gas accumulation, and the current goaf analysis area is identified as a gas accumulation dominant area. For goaf analysis areas that are not identified as collaborative conflict areas or complex collaborative areas, when the i-th goaf analysis area is a gas accumulation controlled area and a coal spontaneous combustion risk area, it indicates that the main risk of the current goaf analysis area is the oxidation and self-heating of residual coal, and the current goaf analysis area is identified as a coal spontaneous combustion dominant area. S52. Based on the collaborative prevention and control assessment results of each goaf analysis area, determine the corresponding collaborative prevention and control strategies for gas drainage and inert gas injection, including: For the coordinated controlled area, maintain the current negative pressure of the corresponding gas extraction branch and the current inert flow rate of the corresponding inert injection branch; For areas dominated by gas accumulation, the negative pressure of the corresponding gas extraction branch will be increased by 5% to 15% based on the current negative pressure, while maintaining the current inert injection flow rate of the corresponding inert injection branch. For areas dominated by spontaneous combustion of coal, the negative pressure of the corresponding gas extraction branch will be reduced by 5% to 10% based on the current negative pressure, and the inert injection flow rate of the corresponding inert injection branch will be increased by 10% to 30% based on the current inert injection flow rate. For the composite synergistic region, the negative pressure of the gas drainage branch corresponding to the i-th goaf analysis area is increased by 3% to 8% based on the current negative pressure, and the inert flow rate of the inert injection branch corresponding to the j-th goaf analysis area is increased by 10% to 20% based on the current inert flow rate; For areas of coordinated conflict, the current negative pressure of the gas drainage branch corresponding to the i-th goaf analysis area is maintained, and the inert flow rate of the inert injection branch corresponding to the j-th goaf analysis area is increased by 20% to 30% based on the current inert flow rate, so as to reduce the degree of additional oxygen supply impact of enhanced gas drainage on the j-th goaf analysis area. S53. After adjusting the gas extraction negative pressure and inertia injection flow rate, re-acquire the goaf status monitoring data and prevention and control operation data according to the fixed sampling cycle, and re-analyze the gas accumulation status and the residual coal oxygen supply self-heating status. When there are both gas accumulation risk areas and coal spontaneous combustion risk areas, re-analyze the collaborative prevention and control conflict, and re-analyze the comprehensive analysis based on the updated gas accumulation assessment results, coal spontaneous combustion assessment results and collaborative prevention and control conflict coefficient. Iteratively update the gas extraction negative pressure and inertia injection flow rate to achieve continuous optimization of collaborative prevention and control parameters.

[0048] Method for obtaining the collaborative conflict assessment threshold Cth: The calibration target of the collaborative conflict assessment threshold Cth is to determine the critical value of the collaborative prevention and control conflict coefficient that can distinguish between "composite collaborative areas" and "collaborative conflict areas".

[0049] A standard database for the coordinated prevention and control of spontaneous combustion of coal through gas drainage in target coal mine goaf areas was constructed. The database contains no fewer than 500 samples, covering different degrees of gas accumulation and retention, different degrees of oxygen supply and self-heating from residual coal, different spatial distances between risk areas, different effective influence radii of drainage borehole groups, different degrees of negative pressure increase during drainage, and different degrees of oxygen concentration increase in coal spontaneous combustion risk areas. Each sample includes the gas accumulation and retention coefficient, residual coal oxygen supply and self-heating coefficient, spatial correlation, positive change in drainage negative pressure, positive change in oxygen concentration, oxygen supply response induced by drainage, coordinated prevention and control conflict coefficient, and results of changes in coal spontaneous combustion risk after enhanced gas drainage.

[0050] Three or more engineering technicians with experience in coal mine gas extraction, coal spontaneous combustion prevention and control and mine disaster collaborative management will use the "gold standard" to label each group of samples based on the increase in oxygen concentration, carbon monoxide changes, temperature changes and the results of residual coal oxidation and self-heating development in the coal spontaneous combustion risk area after enhanced gas extraction, and classify them into composite synergy and synergistic conflict.

[0051] According to the method for calculating the collaborative prevention and control conflict coefficient of the present invention, the collaborative prevention and control conflict coefficient corresponding to each sample is calculated uniformly, and the ROC curve analysis is used to take the dividing point with the largest Youden index between the two types of samples as the collaborative conflict assessment threshold Cth.

[0052] Combining the characteristics of this invention, the collaborative prevention and control conflict coefficient is calculated with equal weights from three parts: the product of the gas accumulation and retention coefficient and the self-heating coefficient of residual coal oxygen supply, spatial correlation, and extraction-induced oxygen supply response. The first term is the product of two quantities between 0 and 1, and the extraction-induced oxygen supply response is also obtained by multiplying two periodic changes, which is usually less than the spatial correlation. Therefore, the effective discrimination interval of the collaborative prevention and control conflict coefficient is generally lower than 0.5. The preferred collaborative conflict assessment threshold Cth is 0.25. When the collaborative prevention and control conflict coefficient reaches or exceeds 0.25, it indicates that there is already a significant spatial correlation and extraction-induced oxygen supply response between the corresponding gas accumulation risk area and coal spontaneous combustion risk area, and the corresponding area is identified as a collaborative conflict area; when it is lower than 0.25, it is identified as a composite collaborative area.

[0053] In this embodiment, differentiated prevention and control measures are implemented according to different states such as collaborative conflict, compound collaboration, collaborative control, gas accumulation-dominated, and coal spontaneous combustion-dominated, so that the negative pressure of gas extraction and the inert flow rate are no longer adjusted in a uniform manner. In particular, maintaining the negative pressure of gas extraction and prioritizing the increase of the inert flow rate in the coal spontaneous combustion risk area under the collaborative conflict state can avoid further enhancing the additional oxygen supply effect of extraction while taking into account the control of gas accumulation. And through the adjusted re-monitoring and iterative updates, a continuously optimized closed-loop prevention and control process is formed.

[0054] Example 10 For a collaborative prevention and control system for gas accumulation and spontaneous combustion in coal mine goaf areas, please refer to [link / reference]. Figure 2 Specifically, including: The goaf data acquisition and preprocessing module is used to obtain an electronic distribution map of the goaf of the target coal mine, divide the goaf of the target coal mine into several goaf analysis areas, collect goaf status monitoring data, prevention and control operation data and historical benchmark data of each goaf analysis area, and obtain preprocessed goaf status monitoring data and prevention and control operation data after preprocessing. The gas accumulation assessment module is used to calculate the gas accumulation retention coefficient of each goaf analysis area based on historical benchmark data, preprocessed goaf status monitoring data and prevention and control operation data, and obtain the gas accumulation assessment results after assessment. The residual coal self-heating assessment module is used to calculate the oxygen supply self-heating coefficient of residual coal in each goaf analysis area based on historical benchmark data and pre-processed goaf status monitoring data, and obtain the coal self-ignition assessment results after assessment. The collaborative prevention and control conflict analysis module is used to calculate and obtain the collaborative prevention and control conflict coefficient based on the electronic distribution map of the goaf of the target coal mine, the gas accumulation assessment results and the coal spontaneous combustion assessment results, combined with the pre-processed goaf status monitoring data and prevention and control operation data. The collaborative prevention and control strategy optimization module is used to obtain the collaborative prevention and control assessment results of each goaf analysis area based on the gas accumulation assessment results, coal spontaneous combustion assessment results, and collaborative prevention and control conflict coefficient; based on the collaborative prevention and control assessment results and prevention and control operation data, the negative pressure of gas extraction and the inert injection flow rate are adjusted, and the goaf status monitoring data and prevention and control operation data are iteratively updated based on the adjusted goaf status monitoring data and prevention and control operation data.

[0055] In this embodiment, by setting up a goaf data acquisition and preprocessing module, a gas accumulation assessment module, a residual coal self-heating assessment module, a collaborative prevention and control conflict analysis module, and a collaborative prevention and control strategy optimization module, the spatial information, status monitoring information, prevention and control operation information, gas accumulation assessment results, coal spontaneous combustion assessment results, and collaborative prevention and control conflict results of the goaf can be processed in layers according to the order of risk identification, conflict analysis, and strategy optimization. This enables the collaborative analysis of gas accumulation risk and coal spontaneous combustion risk, as well as the linkage optimization of gas extraction negative pressure and inert injection flow rate, thereby improving the overall coordination and pertinence of goaf complex disaster prevention and control.

[0056] It should be noted that all calculation formulas in this application employ regression analysis, including but not limited to machine learning algorithms, to deeply analyze the collected parameters and identify their natural trends and interrelationships. Specialized software, such as Python's Scikit-learn library or the R language, is used to automatically generate mathematical models that match the data. Then, cross-validation and other methods are used to objectively evaluate the model performance, and continuous feedback and optimization are combined to ensure that the created formulas truly reflect the inherent laws of the data, thereby guaranteeing their effectiveness and accuracy. In all calculation formulas in this application, the parameters in each formula undergo dimensionless processing within a consistent range to ensure that different physical quantities are compared on the same scale; dimensionless processing techniques include, but are not limited to, min-max-normalization and Z-score standardization. The algorithm of this invention is implemented as a Python script. Before executing the core logic, the program first executes a data loading module (e.g., using the widely used pandas library in Python) configured to read the aforementioned spreadsheet file and load its contents into the program's working memory (e.g., a DataFrame data structure). Subsequent algorithm steps will directly query and retrieve the required configuration parameters from this in-memory data structure.

[0057] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for the coordinated prevention and control of gas accumulation and spontaneous combustion of coal in coal mine goaf areas, characterized in that, The specific steps include: Step 1: Obtain the electronic distribution map of the goaf of the target coal mine, divide the goaf of the target coal mine into several goaf analysis areas, collect goaf status monitoring data, prevention and control operation data and historical benchmark data of each goaf analysis area, and obtain preprocessed goaf status monitoring data and prevention and control operation data after preprocessing. Step 2: Based on historical benchmark data, preprocessed goaf status monitoring data, and prevention and control operation data, calculate the gas accumulation retention coefficient of each goaf analysis area, and obtain the gas accumulation assessment results after evaluation. Step 3: Based on historical benchmark data and pre-processed goaf status monitoring data, calculate the oxygen supply self-heating coefficient of residual coal in each goaf analysis area, and obtain the coal spontaneous combustion assessment results after evaluation. Step 4: Based on the electronic distribution map of the goaf of the target coal mine, the gas accumulation assessment results, and the coal spontaneous combustion assessment results, combined with the pre-processed goaf status monitoring data and prevention and control operation data, calculate and obtain the collaborative prevention and control conflict coefficient. Step 5: Based on the gas accumulation assessment results, coal spontaneous combustion assessment results, and collaborative prevention and control conflict coefficient, obtain the collaborative prevention and control assessment results for each goaf analysis area; based on the collaborative prevention and control assessment results and prevention and control operation data, adjust the gas extraction negative pressure and inert injection flow rate, and iteratively update the goaf status monitoring data and prevention and control operation data obtained after adjustment.

2. The method for coordinated prevention and control of gas accumulation and spontaneous combustion of coal in coal mine goaf areas according to claim 1, characterized in that: Step one includes: S11. Using GIS technology and target coal mine surveying data, obtain an electronic distribution map of the target coal mine goaf, including the working face spatial boundary, working face advance direction, working face dip direction, goaf monitoring location, gas drainage branches and their connected drainage borehole groups, and inert injection branch location; use the gas drainage effective influence range determination method to obtain the effective influence radius of each drainage borehole group; combine the goaf monitoring location and the effective influence range of each drainage borehole group, and use the spatial grid division method to divide the target coal mine goaf into several goaf analysis areas; obtain the spatial coordinates of the geometric center of each goaf analysis area, and determine the gas drainage branches, drainage borehole groups, and inert injection branches corresponding to each goaf analysis area; S12. Monitor the gas and temperature status of any goaf analysis area in real time according to a fixed sampling cycle, and collect goaf status monitoring data, including gas concentration, oxygen concentration, carbon monoxide concentration and temperature. S13. Monitor the gas extraction process and inertia injection process of any goaf analysis area in real time according to a fixed sampling period, and collect prevention and control operation data, including the extraction flow rate, extraction negative pressure and current inertia injection flow rate of the corresponding gas extraction branch. S14. Obtain historical monitoring records and historical prevention and control operation records during the historical stable operation period of the target coal mine goaf area, and collect historical benchmark data, including historical gas concentration, historical oxygen concentration, historical carbon monoxide concentration, historical temperature, historical drainage flow rate and historical drainage negative pressure. S15. Perform time correspondence and abnormal data processing on the goaf status monitoring data and prevention and control operation data according to the sampling time to obtain preprocessed goaf status monitoring data and prevention and control operation data.

3. The method for coordinated prevention and control of gas accumulation and spontaneous combustion of coal in coal mine goaf areas according to claim 2, characterized in that: Step two includes: S21. Based on historical benchmark data, pre-processed goaf status monitoring data, and prevention and control operation data, determine the historical stable operating lower limit and historical stable operating upper limit of gas concentration, extraction flow rate, and extraction negative pressure, respectively. Based on the historical stable operating lower limit and historical stable operating upper limit corresponding to each parameter, perform dimensionless normalization processing on the gas concentration, extraction flow rate, and extraction negative pressure of any goaf analysis area in the current sampling period and the previous sampling period to obtain the normalized gas concentration, normalized gas concentration, normalized extraction flow rate, normalized extraction negative pressure, and normalized extraction negative pressure of the current sampling period and the previous sampling period. S22. Based on the normalized gas concentration of the current sampling period and the previous sampling period in any goaf analysis area, calculate and obtain the positive change in gas concentration. S23. Calculate and obtain the extraction transfer effectiveness based on the normalized extraction flow rate and normalized extraction negative pressure of the current sampling period.

4. The method for coordinated prevention and control of gas accumulation and spontaneous combustion of coal in coal mine goaf areas according to claim 3, characterized in that: Step two also includes: S24. Based on the normalized gas concentration, positive change in gas concentration, and extraction and transfer effectiveness of the current sampling period, calculate the gas accumulation and retention coefficient of any goaf analysis area. S25. By setting a preset gas accumulation assessment threshold and comparing it with the gas accumulation retention coefficient of any goaf analysis area, the gas accumulation assessment results are obtained, including: When the gas accumulation retention coefficient is less than the gas accumulation assessment threshold, the current goaf analysis area is determined to be a gas accumulation controlled area; When the gas accumulation retention coefficient is greater than or equal to the gas accumulation assessment threshold, the current goaf analysis area is identified as a gas accumulation risk area.

5. The method for coordinated prevention and control of gas accumulation and spontaneous combustion of coal in coal mine goaf areas according to claim 4, characterized in that: Step three includes: S31. Based on historical benchmark data and pre-processed goaf status monitoring data, determine the historical stable operating lower limit and historical stable operating upper limit for carbon monoxide concentration, temperature, and oxygen concentration, respectively. Based on the historical stable operating lower limit and historical stable operating upper limit corresponding to each parameter, perform dimensionless normalization processing on the carbon monoxide concentration, temperature, and oxygen concentration of any goaf analysis area in the current sampling period and the previous sampling period to obtain the normalized carbon monoxide concentration in the current sampling period and the normalized carbon monoxide concentration in the previous sampling period, the normalized temperature in the current sampling period and the normalized temperature in the previous sampling period, and the normalized oxygen concentration in the current sampling period and the normalized oxygen concentration in the previous sampling period. S32. Based on the normalized carbon monoxide concentration of the current sampling period and the previous sampling period of any goaf analysis area, calculate and obtain the positive change in carbon monoxide concentration. S33. Based on the normalized temperature of the current sampling period and the previous sampling period of any goaf analysis area, calculate and obtain the positive temperature change. S34. Based on the normalized oxygen concentration of the current sampling period and the previous sampling period in any goaf analysis area, calculate and obtain the change in oxygen consumption.

6. The method for coordinated prevention and control of gas accumulation and spontaneous combustion of coal in coal mine goaf areas according to claim 5, characterized in that: Step three also includes: S35. Based on the positive changes in carbon monoxide concentration, temperature, and oxygen consumption, calculate the self-heating coefficient of residual coal oxygen supply in any goaf analysis area. S36. By setting a preset coal spontaneous combustion assessment threshold and comparing it with the oxygen supply autoheating coefficient of residual coal in any goaf analysis area, the coal spontaneous combustion assessment results are obtained, including: When the oxygen supply self-heating coefficient of the residual coal is less than the coal spontaneous combustion assessment threshold, the current goaf analysis area is determined as a coal spontaneous combustion controlled area. When the oxygen supply self-heating coefficient of the residual coal is greater than or equal to the coal spontaneous combustion assessment threshold, the current goaf analysis area is identified as a coal spontaneous combustion risk area.

7. The method for coordinated prevention and control of gas accumulation and spontaneous combustion of coal in coal mine goaf areas according to claim 6, characterized in that: Step four includes: S41. Based on the gas accumulation assessment results and coal spontaneous combustion assessment results, obtain the distribution of gas accumulation risk areas and coal spontaneous combustion risk areas in each goaf analysis area; take the goaf analysis area corresponding to any gas accumulation risk area as the first correlation analysis area; based on the spatial coordinates of the geometric center of each goaf analysis area, use the spatial Euclidean distance calculation method to obtain the spatial distance between the first correlation analysis area and the goaf analysis areas corresponding to each coal spontaneous combustion risk area; take the goaf analysis area corresponding to the coal spontaneous combustion risk area with the smallest spatial distance as the second correlation analysis area, and obtain the spatial distance between the first correlation analysis area and the second correlation analysis area; S42. Based on the spatial distance between the first correlation analysis region and the second correlation analysis region, and the effective influence radius of the gas drainage branch connected to the drainage borehole group in the first correlation analysis region, calculate and obtain the spatial correlation degree. S43. Based on the normalized extraction negative pressure of the gas extraction branch corresponding to the first correlation analysis region in the current sampling period and the previous sampling period, calculate the positive change in extraction negative pressure. S44. Based on the oxygen concentration of the current sampling period and the previous sampling period in the second correlation analysis region, perform dimensionless normalization processing to obtain the normalized oxygen concentration of the current sampling period and the previous sampling period, and calculate the positive change in oxygen concentration.

8. The method for coordinated prevention and control of gas accumulation and spontaneous combustion of coal in coal mine goaf areas according to claim 7, characterized in that: Step four also includes: S45. Based on the positive change in negative pressure and the positive change in oxygen concentration, calculate the oxygen supply response degree induced by extraction between the first correlation analysis region and the second correlation analysis region. S46. Based on the carbon monoxide concentration, temperature, and oxygen concentration of the current sampling period and the previous sampling period in the second correlation analysis area, the residual coal oxygen supply self-heating coefficient of the second correlation analysis area is obtained by using dimensionless normalization, change extraction, and multi-parameter equal weight fusion calculation methods. Based on the gas accumulation and retention coefficient of each goaf analysis area, the gas accumulation and retention coefficient corresponding to the first correlation analysis area is obtained. Combined with the residual coal oxygen supply self-heating coefficient, spatial correlation degree, and extraction-induced oxygen supply response degree of the second correlation analysis area, the collaborative prevention and control conflict coefficient is calculated.

9. The method for coordinated prevention and control of gas accumulation and spontaneous combustion of coal in coal mine goaf areas according to claim 8, characterized in that: Step five includes: S51. By setting a pre-defined collaborative conflict assessment threshold and combining it with the gas accumulation assessment results, coal spontaneous combustion assessment results, and collaborative prevention and control conflict coefficient, a comprehensive analysis is conducted to obtain the collaborative prevention and control assessment results for each goaf analysis area, including: When the collaborative prevention and control conflict coefficients corresponding to the first and second association analysis regions are greater than or equal to the collaborative conflict assessment threshold, the first and second association analysis regions will be preferentially identified as collaborative conflict regions. For the first and second association analysis regions that are not identified as collaborative conflict regions and whose corresponding collaborative prevention and control conflict coefficients are less than the collaborative conflict assessment threshold, the first and second association analysis regions are identified as composite collaborative regions. For goaf analysis areas that are not identified as collaborative conflict areas or composite collaborative areas, when any goaf analysis area is simultaneously a gas accumulation controlled area and a coal spontaneous combustion controlled area, the current goaf analysis area will be identified as a collaboratively controlled area. For goaf analysis areas that are not identified as collaborative conflict areas or complex collaborative areas, if any goaf analysis area is a gas accumulation risk area and a coal spontaneous combustion controlled area, the current goaf analysis area will be identified as a gas accumulation dominant area. For goaf analysis areas that are not identified as collaborative conflict areas or complex collaborative areas, if any goaf analysis area is a gas accumulation controlled area and a coal spontaneous combustion risk area, the current goaf analysis area will be identified as a coal spontaneous combustion dominant area. S52. Based on the collaborative prevention and control assessment results of each goaf analysis area, determine the corresponding collaborative prevention and control strategies for gas drainage and inert gas injection, including: For the coordinated controlled area, maintain the current negative pressure of the corresponding gas extraction branch and the current inert flow rate of the corresponding inert injection branch; For areas dominated by gas accumulation, the negative pressure of the corresponding gas extraction branch will be increased by 5% to 15% based on the current negative pressure, while maintaining the current inert injection flow rate of the corresponding inert injection branch. For areas dominated by spontaneous combustion of coal, the negative pressure of the corresponding gas extraction branch will be reduced by 5% to 10% based on the current negative pressure, and the inert injection flow rate of the corresponding inert injection branch will be increased by 10% to 30% based on the current inert injection flow rate. For the composite synergistic region, the negative pressure of the gas drainage branch corresponding to the first correlation analysis region will be increased by 3% to 8% based on the current negative pressure, and the inert flow rate of the inert injection branch corresponding to the second correlation analysis region will be increased by 10% to 20% based on the current inert flow rate. For areas of coordinated conflict, maintain the current negative pressure of the gas drainage branch corresponding to the first correlation analysis area, and increase the inert flow rate of the inert injection branch corresponding to the second correlation analysis area by 20% to 30% based on the current inert flow rate; S53. After adjusting the gas extraction negative pressure and inertia injection flow rate, re-acquire the goaf status monitoring data and prevention and control operation data according to the fixed sampling cycle, and re-analyze the gas accumulation status and the residual coal oxygen supply self-heating status. When there are both gas accumulation risk areas and coal spontaneous combustion risk areas, re-analyze the collaborative prevention and control conflict, and re-analyze the comprehensive analysis based on the updated gas accumulation assessment results, coal spontaneous combustion assessment results and collaborative prevention and control conflict coefficient. Iteratively update the gas extraction negative pressure and inertia injection flow rate to achieve continuous optimization of collaborative prevention and control parameters.

10. A system for the coordinated prevention and control of gas accumulation and spontaneous combustion of coal in coal mine goaf areas, applied to the method for the coordinated prevention and control of gas accumulation and spontaneous combustion of coal in coal mine goaf areas as described in any one of claims 1 to 9, characterized in that, include: The goaf data acquisition and preprocessing module is used to obtain an electronic distribution map of the goaf of the target coal mine, divide the goaf of the target coal mine into several goaf analysis areas, collect goaf status monitoring data, prevention and control operation data and historical benchmark data of each goaf analysis area, and obtain preprocessed goaf status monitoring data and prevention and control operation data after preprocessing. The gas accumulation assessment module is used to calculate the gas accumulation retention coefficient of each goaf analysis area based on historical benchmark data, preprocessed goaf status monitoring data and prevention and control operation data, and obtain the gas accumulation assessment results after assessment. The residual coal self-heating assessment module is used to calculate the oxygen supply self-heating coefficient of residual coal in each goaf analysis area based on historical benchmark data and pre-processed goaf status monitoring data, and obtain the coal self-ignition assessment results after assessment. The collaborative prevention and control conflict analysis module is used to calculate and obtain the collaborative prevention and control conflict coefficient based on the electronic distribution map of the goaf of the target coal mine, the gas accumulation assessment results and the coal spontaneous combustion assessment results, combined with the pre-processed goaf status monitoring data and prevention and control operation data. The collaborative prevention and control strategy optimization module is used to obtain the collaborative prevention and control assessment results of each goaf analysis area based on the gas accumulation assessment results, coal spontaneous combustion assessment results, and collaborative prevention and control conflict coefficient. Based on the collaborative prevention and control assessment results and prevention and control operation data, the negative pressure of gas extraction and the inert flow rate were adjusted, and the data were iteratively updated based on the newly acquired goaf status monitoring data and prevention and control operation data.

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