A low-gas mine gas emission anomaly source precision detection and treatment method

Abstract

The application discloses a low-gas mine gas emission abnormal source precision detection and treatment method, which is used for solving the problem of low-gas mine gas abnormal emission. First, the monitoring points and the monitoring point positions are determined, and all gas monitoring data are obtained through a mine monitoring system; data analysis is carried out based on SPC control chart theory, and a gas emission data anomaly criterion is established; the gas emission state is judged through the SPC control chart method, the gas emission abnormal area position is determined, and early warning is carried out; according to the determined gas emission abnormal area, the isotopic analysis method is used to detect the gas emission source and composition; finally, the gas emission abnormal source analysis result is tracked, targeted gas source classification treatment measures are formulated, and then the treatment effect test is carried out. The application can effectively control the low-gas mine gas emission abnormal risk, thereby improving the safety of coal mining.

Description

Technical Field

[0001] This invention relates to the field of mine gas control technology, specifically to a method for accurate detection and control of abnormal sources of gas outbursts in low-gas mines. Background Technology

[0002] Compared to high-gas mines, low-gas mines have a significantly higher probability of gas accidents. This is mainly because coal mining enterprises have a thorough understanding of the control measures and management of high-gas mines, while low-gas mines lack complete gas control technology and do not fully recognize the importance of gas control in management. This makes it easier for local gas concentrations to exceed limits during mine production, potentially leading to related safety accidents. Furthermore, many coal mining enterprises do not fully understand the characteristics of gas occurrence and emission patterns in coal seams, and lack corresponding emergency response measures for abnormal local gas emissions. Such abnormal gas emissions can lead to serious gas accidents. The main sources of gas in coal mining spaces include: gas release from falling coal during mining, gas release during coal transportation, gas release from the coal face, gas release from the goaf, and gas inflow from adjacent coal seams. Due to the uneven distribution of coal seam gas, many factors significantly influence gas emission, including geological structure, mining methods, mining depth, and the gas content of the coal seam itself. Therefore, gas emission rates differ greatly between longwall and tunneling faces. Influenced by mining methods and ventilation, the gas emission rates and characteristics differ between longwall faces, intake airways, return air corners, and return airways. Similarly, gas emission rates differ between tunneling faces and return airways. Although coal mining enterprises monitor gas concentrations, they often employ a one-size-fits-all alarm system, judging gas emission abnormalities solely by gas concentration levels. When an abnormal concentration is detected, an alarm signal is issued, and gas control measures are implemented in both abnormal and non-abnormal areas. Therefore, this alarm system cannot accurately identify the source of abnormal gas emission and cannot propose targeted, point-to-point gas control measures based on the state and source of abnormal gas emission. If a one-size-fits-all alarm concentration index is used, the resulting gas control plan lacks specificity, which often leads to the phenomenon of layer-by-layer escalation of gas management during implementation, increasing the human and material costs of coal mine safety. Therefore, it is urgent to improve the level of precise management of abnormal gas outbursts in low-gas mines. Summary of the Invention

[0003] The purpose of this invention is to provide a method for accurate detection and control of abnormal gas emission sources in low-gas mines. This method can accurately identify and warn of abnormal gas emission areas in tunneling and mining faces, determine the source and main controlling factors of abnormal gas emission, know the abnormal gas emission behavior in advance, formulate scientific and accurate gas prevention and control measures, and eliminate the possibility of gas accidents in advance.

[0004] To achieve the above objectives, the present invention provides a method for precise detection and control of abnormal gas emission sources in low-gas mines, comprising the following steps:

[0005] Step 1: Determine the monitoring points and their locations, and obtain all gas monitoring data through the mine monitoring system;

[0006] Step 2: Perform data analysis based on SPC control chart theory and establish abnormal criteria for gas outburst data;

[0007] Step 3: Determine the gas outburst status using the SPC control chart method, identify the location of abnormal gas outburst areas, and issue an early warning.

[0008] Step 4: Based on the identified abnormal gas emission areas, use isotope analysis to detect the source and composition of the gas emission;

[0009] Step 5: Track the analysis results of abnormal gas emission sources, formulate targeted gas source classification and treatment measures, and then conduct a test on the treatment effect.

[0010] Furthermore, in step 1, determining the monitoring points and their locations involves installing methane concentration sensors in the working coal seam, the longwall face, the upper corner, and the intake and return airway.

[0011] Furthermore, in step 2, when performing statistical analysis using the SPC control chart, the average value λ of the statistical indicator over a certain period is first calculated, and then the upper control limit U and the lower control limit L are calculated respectively:

[0012]

[0013]

[0014] The real-time gas data was normalized using s i Indicators for identifying abnormal gas outbursts:

[0015]

[0016] Furthermore, the specific steps for determining the abnormal gas outburst are as follows:

[0017] When the judgment index s i When the value is ∈ (0, 1.0], the gas emission is considered to be within the normal range and no alarm is triggered;

[0018] When the judgment index s i numerical value s i When the value is greater than 1.0, the gas emission exceeds the control limit, is marked as abnormal, and an alarm is triggered.

[0019] When the judgment index s i numerical value si When the value is less than 0.0, the gas emission exceeds the lower control limit, indicating an abnormality, but no alarm is triggered.

[0020] Furthermore, in step 2, the SPC control chart, based on the mine gas dynamic monitoring system, provides real-time abnormal gas emission status, classifies abnormal areas, and determines the early warning of abnormal gas emission status. Further, in step 3, if an abnormal gas emission status or a trend towards a threat warning occurs, the mine gas dynamic monitoring system will generate a mine gas emission abnormality early warning signal; if an abnormal gas emission warning is generated within the mine's mining space, and it is determined that a trend warning of a threat status occurs within the current shift, then the current abnormal gas emission is defined as a danger warning signal.

[0021] Furthermore, in step 4, isotope source analysis is conducted on the gas outburst anomaly, and the component proportion of different gas sources is calculated based on the gas isotope content of each coal seam.

[0022] Furthermore, in step 5, the gas source differentiation and grading control measures include: Level I control measures, when the absolute outburst is less than 5m³. 3 When the outflow rate is 5 m³ / min, ventilation and auxiliary measures are used for treatment; Level II treatment measures are implemented when the absolute outflow rate is 5 m³ / min. 3 / min and 10m 3 Between / min, high-level borehole and goaf buried pipe extraction methods are used;

[0023] Level III treatment measures are implemented when the absolute outflow exceeds 10m³. 3 When the flow rate is 1 / min, corresponding measures such as shallow hole extraction at the working face, high-level large-diameter directional drilling, and pre-extraction of the mining layer should be used.

[0024] The beneficial effects of this invention are:

[0025] (1) This invention optimizes the method for identifying and warning of abnormal areas of gas outburst in mines, fully explores the data information of gas monitoring points, and establishes a judgment standard and method based on real-time monitoring data of gas outburst;

[0026] (2) This invention introduces a method for analyzing the source of abnormal gas outbursts in mines. Based on isotope tracing, it can realize the cause and composition ratio of abnormal gas outbursts.

[0027] (3) Based on the analysis results of abnormal gas emission status and emission source, this invention proposes appropriate gas control measures to provide support for intelligent and precise gas control in coal mines. Attached Figure Description

[0028] Figure 1 This is a flowchart of the gas outburst anomaly detection and analysis process of the present invention;

[0029] Figure 2 This is a schematic diagram of the coal monitoring points and their layout during mining operations according to the present invention;

[0030] Figure 3 This is a flowchart of the gas outburst anomaly source analysis of the present invention;

[0031] Figure 4 This is a flowchart of the abnormal gas outburst control measures and effect evaluation of the present invention. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] This invention provides a method for precise detection and control of abnormal gas emission sources in low-gas mines, such as... Figure 1 As shown, this method combines a dynamic mine gas monitoring system with gas classification and control measures. It obtains real-time data from both the gas monitoring and extraction systems. Based on the control chart method of Statistical Process Control (SPC), the input gas data is analyzed and compared with the upper and lower limits of the control chart method to calculate the gas emission anomaly index K. This determines whether the gas emission is abnormal. If not, monitoring returns to the initial stage; if the result is abnormal, further analysis of the emission anomaly is required. The specific steps of this method are as follows:

[0034] Step 1: Determine the monitoring points and their locations, and obtain all gas monitoring data through the mine monitoring system. For example... Figure 2 As shown in (a), methane concentration sensors C1 and C2 are installed at the tunneling face and in the return airflow. Figure 2 As shown in (b), methane concentration sensors C0, C1, C2 and C3 are installed in the intake airway, working face, upper corner and return airway of the longwall face, and the monitoring data of all the above gas monitoring points are obtained through the mine monitoring system.

[0035] Step 2: Perform data analysis based on SPC control chart theory and establish anomaly criteria for gas outburst data. Statistical analysis is performed using SPC control charts. First, calculate the average value λ of the statistical indicators over a certain period (or set a reasonable target value). Then, calculate the upper control limit U and the lower control limit L as follows:

[0036]

[0037]

[0038] Given the known upper and lower control limits of the SPC control chart, the real-time gas data is normalized using s i Indicators for identifying abnormal gas outbursts:

[0039]

[0040] Step 3: Determine the gas outburst status using the SPC control chart method, identify the location of abnormal gas outburst areas, and issue an early warning. Based on the constructed gas outburst anomaly judgment criteria, the gas outburst status is judged in real time. The judgment indicators are as follows:

[0041] When the judgment index s i When the value is ∈ (0, 1.0], the gas emission is considered to be within the normal range and no alarm is triggered;

[0042] When the judgment index s i numerical value s i When the value is greater than 1.0, the gas emission exceeds the control limit, is marked as abnormal, and an alarm is triggered.

[0043] When the judgment index s i numerical value s i When the value is less than 0.0, the gas emission exceeds the lower control limit, indicating an abnormality, but no alarm is triggered.

[0044] To improve the accuracy of abnormal hazard assessment, a gas trend early warning method is proposed. Gas emission data for one shift cycle is collected, with one data point read from the database every minute. The first data point is denoted as a1, the i-th data point as ai, and one cycle includes 480 data points. These 480 data points are analyzed, and the average value of the gas monitoring data from the n-th shift is used as the basis for the analysis. Using the baseline value, calculate The anomaly coefficient R i (The calculation formula is as follows). Compare the magnitude of the abnormal coefficient with the critical index. If the critical index is exceeded, a warning signal of abnormal gas outburst trend will be issued.

[0045]

[0046]

[0047] When gas emission data is abnormal, an early warning message is issued based on the SPC control chart theory. The early warning message includes the gas emission data and the location of the abnormal gas emission area.

[0048] Step 4: Based on the identified abnormal gas emission areas, use isotope analysis to detect the source and composition of the gas emission.

[0049] Figure 3 This is a flowchart illustrating the analysis of gas outburst anomalies according to the present invention. Based on the different formation periods of gas reservoirs in various strata, isotopic analysis can reveal different gas sources. By calculating the isotopic content of gas in each coal seam, the component proportions of different gas sources can be obtained. An example of the calculation process is as follows:

[0050] Assuming the gas in the mining area originates from four coal seams (1#, 2#, 3#, and 4#), a quaternary gas mixture source calculation model is established. The volume percentages of gas entering the working face from the four coal seams are a, b, c, and d, respectively; the corresponding methane carbon isotope values ​​are A1, B1, C1, and D1; the carbon dioxide isotope ratios are A2, B2, C2, and D2; and the hydrogen isotope values ​​are A3, B3, C3, and D3. The isotope ratios of methane, carbon dioxide, and hydrogen in the mixture are δ... I δ II δ III The system of four quartic equations in four variables is as follows:

[0051]

[0052] Solving the above equation yields the gas content of each coal seam in the mixed gas.

[0053]

[0054]

[0055] Step 5: Track the analysis results of abnormal gas emission sources, formulate targeted gas source-based and graded control measures, and then conduct control effect verification. In this invention, based on research results, a gas source-based and graded control measure is proposed, classifying the gas control measures according to the magnitude of gas emission, into three levels of control measures, such as... Figure 4 As shown, where,

[0056] Level I control measures: When the absolute outflow is less than 5m³ 3 When the flow rate is / min, ventilation and auxiliary measures should be used for treatment;

[0057] Level II control measures: When the absolute outflow is 5m³ 3 / min and 10m 3 Between / min, high-level borehole and goaf buried pipe extraction methods are used;

[0058] Level III control measures: When the absolute outflow volume exceeds 10m³ 3 When the flow rate is 1 / min, corresponding measures such as shallow hole extraction at the working face, high-level large-diameter directional drilling, and pre-extraction of the mining layer should be used.

[0059] After implementing gas control measures, conduct an evaluation of the effectiveness of the control measures to verify their effectiveness. If the current control effect is found to be unsatisfactory, enhanced measures (i.e., upgrading the level of control measures) can be selected.

[0060] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes that can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention are all within the protection scope of the claims of the present invention.

Claims

1. A method for precise detection and control of abnormal gas emission sources in low-gas mines, characterized in that, Includes the following steps: Step 1: Determine the monitoring points and their locations, and obtain all gas monitoring data through the mine monitoring system; Step 2: Perform data analysis based on SPC control chart theory and establish anomaly criteria for gas outburst data: When using SPC control charts for statistical analysis, first calculate the average value λ of the statistical indicators over a certain period, and then calculate the upper control limit U and the lower control limit L respectively. ； The real-time gas data was normalized using... Indicators for identifying abnormal gas outbursts: ； Step 3: Determine the gas outburst status using the SPC control chart method, identify the location of abnormal gas outburst areas, and issue an early warning. The specific steps for determining the abnormal gas outburst indicators are as follows: When the judgment indicator numerical values At that time, it was assumed that the gas emission was within the normal range, and no alarm was triggered; When the judgment indicator numerical values At this time, the gas emission exceeds the control limit, which is marked as abnormal and triggers an alarm; When the judgment indicator numerical values At this time, the gas emission exceeds the lower control limit, indicating an abnormality, but no alarm is triggered; Step 4: Based on the identified abnormal gas emission areas, use isotope analysis to detect the source and composition of the gas emission; Step 5: Track the analysis results of abnormal gas emission sources, formulate targeted gas source classification and treatment measures, and then conduct a test on the treatment effect.

2. The method for precise detection and control of abnormal gas emission sources in low-gas mines according to claim 1, characterized in that, In step 1, determining the monitoring points and their locations involves installing methane concentration sensors in the tunneling face, the mining face, the upper corner, and the intake and return airways.

3. The method for precise detection and control of abnormal gas emission sources in low-gas mines according to claim 1, characterized in that, In step 2, the SPC control chart is based on the mine gas dynamic monitoring system, which provides real-time abnormal gas outburst status, divides abnormal areas, and determines the early warning of abnormal gas outburst status.

4. The method for precise detection and control of abnormal gas emission sources in low-gas mines according to claim 1, characterized in that, In step 3, if an abnormal gas outburst occurs or a threat warning is issued, the mine gas dynamic monitoring system will generate a mine gas outburst abnormal warning signal. If an abnormal gas outburst warning is issued in the mine mining space, and it is determined that a trend warning of a threat occurs in this shift, then the gas outburst abnormality at this time is defined as a danger warning signal.

5. The method for precise detection and control of abnormal gas emission sources in low-gas mines according to claim 1, characterized in that, In step 4, isotopic source analysis is conducted on the abnormal gas outbursts, and the component proportions of different gas sources are calculated based on the gas isotope content of each coal seam.

6. The method for precise detection and control of abnormal gas emission sources in low-gas mines according to claim 1, characterized in that, In step 5, the gas source differentiation and grading control measures include: Level I control measures are implemented when the absolute outflow is less than 5m³. 3 When the flow rate is / min, ventilation and auxiliary measures should be used for treatment; Level II treatment measures, when the absolute outflow is 5m 3 / min and 10m 3 Between / min, high-level borehole and goaf buried pipe extraction methods are used; Level III treatment measures are implemented when the absolute outflow exceeds 10m³. 3 When the flow rate is / min, corresponding measures such as shallow hole extraction at the working face, high-level large-diameter directional drilling, and pre-extraction of the mining layer should be used.

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