Intelligent prediction system for gas overrun of mine stope face and prediction method thereof

Abstract

The invention relates to an intelligent prediction system and method for gas overrun of a mine stope face, and the system comprises a data collection module, a gas concentration analysis module, a ground stress analysis module, and a gas overrun early warning module. The data acquisition module is used for collecting gas extraction drill hole single-hole accurate metering data and ground stress measurement while drilling data in the working face recovery process; the gas concentration analysis module and the crustal stress analysis module are used for performing corresponding fitting analysis on the acquired single-hole accurate measurement data of the gas extraction drill hole and the crustal stress while-drilling monitoring data to obtain gas and crustal stress early warning indexes; and the gas over-limit early warning module carries out cooperative early warning on gas over-limit accidents in the recovery process according to the fitting result. According to the invention, real-time early warning of gas overrun of the mining roadway is realized, and the production safety of a mine is effectively ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of gas disaster prediction, and in particular to an intelligent prediction system and a prediction method for gas over-limit in a mining working face. Background Art

[0002] Coal energy is still the main component of my country's energy structure. Due to the special geological environment in my country, coal mining is mostly carried out in underground mining mode. Most mines contain gas, and more than half of them have a large amount of gas or gas outburst problems. In addition, the spatial density of coal is large, the permeability between coal seams is low, and it is not easy to extract before mining, so gas disasters are very likely to occur during mining. Coal mine gas overlimit is an abnormal phenomenon in which the gas concentration in the underground working environment of coal mines exceeds the prescribed safety limit. Gas overlimit is likely to cause catastrophic accidents such as coal and gas outbursts and gas explosions. Therefore, avoiding underground gas accumulation or gas overlimit is a key link in preventing and controlling coal and gas outbursts and gas explosions, and it is also a necessary means to provide workers with a good working environment. In order to prevent such accidents, coal mines are generally equipped with safety monitoring systems to realize online monitoring of environmental gas concentrations in key areas underground, as well as automatic alarms after gas overlimit.

[0003] Gas over-limit prevention and control is a key link in coal mine gas disaster prevention and control. Gas disasters are affected by many factors, with complex causes and easy to form coupled disasters. The existing safety monitoring system has problems such as single measurement parameters, inaccurate measurement, and untimely response. Therefore, there is an urgent need for a method to combine various gas monitoring data to intelligently predict gas over-limit in the working face. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide an intelligent prediction system and prediction method for gas exceeding the limit in the coal mine recovery working face. Through intelligent analysis of high-precision low gas flow monitoring data of extraction boreholes and ground stress drilling monitoring data, non-contact continuous intelligent early warning of the risk of gas exceeding the limit in the coal mine recovery working face is achieved, which is conducive to the advance prevention and control of coal mine gas accidents.

[0005] The object of the present invention is achieved in that:

[0006] An intelligent prediction system for gas over-limit in a mining face, comprising a data acquisition module, a gas concentration analysis module, a ground stress analysis module and a gas over-limit early warning module. The data acquisition module collects precise metering data of a single gas extraction drilling hole and ground stress while drilling measurement data during the mining process of the working face; the gas concentration analysis module and the ground stress analysis module perform corresponding fitting analysis on the collected precise metering data of a single gas extraction drilling hole and ground stress while drilling monitoring data to obtain gas and ground stress early warning indicators; the gas over-limit early warning module coordinates early warning of gas over-limit accidents during the mining process according to the fitting results;

[0007] The data acquisition module is used to collect monitoring data and provide early warning basic data for other modules; the data acquisition module mainly includes a single-hole gas precision meter and a drilling ground stress measuring instrument, and is connected to the corresponding analysis module through a wireless sensor;

[0008] The gas concentration analysis module is used to analyze the changes in the gas concentration characteristics of the mining face in real time, and predict the gas concentration sequence of the mining face in the future, obtain the real-time change curve of ultra-low gas concentration, the prediction curve of gas concentration change and the maximum value of gas concentration in the future, and obtain the prediction index of gas concentration;

[0009] The geostress analysis module is used to analyze the changes in the geostress of hard and soft rocks, and calculate the in-situ geostress of soft and hard rocks by combining the output energy of the drill rig, the amount of drill cuttings and the particle size distribution of drill cuttings during the drilling process, so as to obtain the in-situ geostress change curve and the prediction curve as well as the maximum value of the future geostress, and obtain the prediction index of the geostress while drilling;

[0010] The gas over-limit early warning module identifies the gas over-limit risk based on the gas concentration analysis module and the ground stress analysis module, and gives an early warning result of the gas over-limit risk size;

[0011] The drilling rig is connected to a gas over-limit warning module, which is respectively connected to a ground stress analysis module and a gas concentration analysis module, which is connected to each downhole ground stress measuring instrument, and which is connected to each single-hole gas precision meter, thereby obtaining gas single-hole precision metering data and ground stress downhole measurement data in real time while extracting gas.

[0012] Furthermore, by utilizing the pre-extraction tunnel extraction boreholes, i.e., the high tunnel or the bottom tunnel, a drilling rig is used from the drilling site of the pre-extraction tunnel to construct through-layer boreholes to the mining working face arranged in the coal seam. The current coal mining machine is located 3 drilling sites ahead of all the through-layer boreholes installed with single-hole gas precision meters and downhole ground stress measuring instruments.

[0013] Furthermore, the through-layer drilling holes are arranged in the entire mining face, including the range of 15 m outside the tunnel contour line of two mining face tunnels on the mining face.

[0014] Furthermore, the spacing between the through-layer drill holes is 2R, where R is the drilling extraction radius.

[0015] Furthermore, a drilling site is arranged every 4 to 6 rows of through-layer boreholes, and the distance between each drilling site does not exceed 10 m.

[0016] Furthermore, the single-hole gas precision meter is arranged in the middle of the through-layer borehole, and the drilling stress measuring instrument is arranged on the mining working face.

[0017] An intelligent prediction method for gas over-limit in a mine recovery working face, based on the above-mentioned intelligent prediction system for gas over-limit in a mine recovery working face, includes the following contents:

[0018] Step 1: Drilling and collecting data;

[0019] Through-drilling is carried out in the coal seam pre-extraction tunnel to obtain the single-hole gas data and ground stress drilling data of at least three drilling sites of the leading coal mining machine in the entire mining face in real time;

[0020] Step 2: extracting gas monitoring data and ground stress while drilling monitoring data;

[0021] Extract the current gas monitoring value M t Extract the drilling monitoring data of the ground stress of the coal seam roof rock layer from the gas monitoring data of the time periods T1 and T2 before the current moment;

[0022] Step 3: Calculate the index N t ;

[0023] Index N t is the average value of the gas monitoring data in the T1 time period before the current moment. Based on the gas monitoring data in the T1 time period, the gas concentration analysis module calculates the index N t ; Index N t The calculation method is:

[0024] ;

[0025] Step 4: Calculate the index P t and the in-situ stress α t ;

[0026] According to the gas monitoring data of time period T2, the gas concentration analysis module calculates the index P t , index P t is the average value of gas monitoring data in the time period T2 before the current moment; the index P tThe calculation method is:

[0027] ;

[0028] Among them, y i is the gas monitoring data of the working face at different times in the T2 period; v is the advancing speed of the working face; l is the advancing distance of the working face;

[0029] According to the ground stress monitoring data of time period T2, the in-situ ground stress α is calculated by the ground stress analysis module. t , and send the above index data to the ground for backup; in-situ ground stress α t The calculation method is:

[0030] ;

[0031] Step 5: Determine and warn;

[0032] The short-term gas over-limit warning threshold N0 is the index N of the time period T1 before the current moment. t ; The threshold M0 is the average value P of the gas monitoring data in the T2 time period before the current moment t 200% of ; The calculation method of threshold α0 is:

[0033] ;

[0034] Among them, z i is the in-situ ground stress monitoring data of rock formations in different boreholes during the T2 period; v is the working face advancement speed; l is the working face advancement distance;

[0035] When the index N t When the gas monitoring value M is greater than the threshold value N0, the gas over-limit warning module will issue a short-term gas over-limit warning. t When it is greater than the threshold value M0, an emergency warning of gas exceeding the limit is issued;

[0036] When the in-situ ground stress monitoring data Z of the rock formation to be tested is greater than the threshold value α0, an emergency warning of gas exceeding the limit is issued; after the warning is triggered, the gas-electric locking operation is immediately implemented to cut off the power supply of the coal mining machine and the coal mining machine stops working.

[0037] Furthermore, the time period T1 is 10 to 15 minutes; the time period T2 is determined according to the advancing speed of the working face.

[0038] Furthermore, in step 5, if N t If the gas monitoring value M is greater than N0, a short-term warning of gas exceeding the limit for 10 to 15 minutes is issued. Repeat this step continuously. If there are two or more short-term warnings of gas exceeding the limit, the gas electric interlocking operation is immediately implemented to cut off the power supply of the coal mining machine and stop the coal mining machine. If the current gas monitoring value Mt If it is greater than M0, an emergency warning of gas over-limit will be issued, and the gas-electric interlocking operation will be immediately implemented to cut off the power supply of the coal mining machine and stop the coal mining machine from working.

[0039] Furthermore, the gas concentration range obtained by the single-hole gas precise metering data is 0~100%.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention realizes in-depth mining of mine gas monitoring data and ground stress while drilling monitoring data. Through real-time monitoring and analysis of gas parameters and ground stress parameters of at least three drilling sites of the advanced coal mining machine in the mining face (including the range of 15 m outside the contour line of the two tunnels), the single-hole precise measurement of gas extraction boreholes and ground stress while drilling monitoring are realized. Based on the monitoring data of gas and ground stress, the gas flow of the mining tunnel is monitored collaboratively, and the real-time early warning of gas exceeding the limit in the mining tunnel is realized, which effectively ensures the production safety of the mine. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the structure of the prediction system of the present invention.

[0043] Figure 2 This is a schematic diagram of the layout inside the drilling site of Example 1 of the present invention.

[0044] Figure 3 This is a schematic plan view of the hole arrangement of Example 1 of the present invention.

[0045] Figure 4 It is the front view of the hole arrangement of embodiment 1 of the present invention.

[0046] Figure 5 It is a side view of the hole arrangement of embodiment 1 of the present invention.

[0047] Figure 6 This is a schematic diagram of the internal layout of a drilling site according to Embodiment 2 of the present invention.

[0048] Figure 7 This is a schematic plan view of the hole arrangement of Example 2 of the present invention.

[0049] Figure 8 This is a front view of the hole arrangement of embodiment 2 of the present invention.

[0050] Fig. 9 It is a side view of the hole arrangement of embodiment 2 of the present invention.

[0051] in:

[0052] High-extraction lane 1, drilling site 2, coal seam 3, mining face 4, through-layer drill hole 5, mining face lane 6, single-hole gas precision meter 7, drilling-while-drilling ground stress measuring instrument 8, drilling rig 9, ground stress analysis module 10, gas concentration analysis module 11, gas over-limit warning module 12, bottom extraction lane 13. DETAILED DESCRIPTION

[0053] In order to better understand the technical solution of the present invention, the following will be described in detail in conjunction with the relevant illustrations. It should be understood that the following specific embodiments are not intended to limit the specific implementation of the technical solution of the present invention, and are only implementations that can be adopted by the technical solution of the present invention. It should be noted that the description of the positional relationship of each component in this article, such as component A being located above component B, is based on the description of the relative positions of the components in the illustration, and is not intended to limit the actual positional relationship of the components.

[0054] Embodiment 1:

[0055] See also Figure 1-Figure 5 , Figure 1 A structural schematic diagram of an intelligent prediction system for gas over-limit in a mining face is drawn. As shown in the figure, an intelligent prediction system for gas over-limit in a mining face of a mine in this embodiment 1 includes a data acquisition module, a gas concentration analysis module 11, a ground stress analysis module 10 and a gas over-limit warning module 12. The data acquisition module collects borehole gas parameter data (i.e., gas extraction drilling single hole precise metering data) and ground stress while drilling measurement data during the mining process of the working face; the gas concentration analysis module 11 and the ground stress analysis module 10 perform corresponding fitting analysis on the collected gas extraction drilling single hole precise metering data and ground stress while drilling monitoring data to obtain gas and ground stress warning indicators; the gas over-limit warning module 12 coordinates and warns of gas over-limit accidents in the mining process according to the fitting results.

[0056] The data acquisition module is used to collect monitoring data and provide basic early warning data for other modules; the data acquisition module mainly includes a single-hole gas precision meter 7 and a drilling stress measuring instrument 8, and is connected to the corresponding analysis module through a wireless sensor.

[0057] The gas concentration analysis module 11 is mainly used to analyze the changes in the gas concentration characteristics of the mining face in real time, and to predict the gas concentration sequence of the mining face in the future, to obtain the real-time change curve of the ultra-low gas concentration and the predicted curve of the gas concentration change and the maximum value of the gas concentration that may appear in the future, and to obtain the prediction index of the gas concentration; the gas concentration analysis module 11 can use the YZC6 gas extraction pipeline multi-parameter measuring instrument software (2023SR1201469) on the market.

[0058] The geostress analysis module 10 is mainly used to analyze the changes in the geostress of hard and soft rocks, and calculate the in-situ geostress of soft and hard rocks in combination with the output energy of the drill rig, the amount of drill cuttings and the particle size distribution of drill cuttings during the drilling process, to obtain the in-situ geostress change curve and the prediction curve as well as the maximum value of the future geostress, and obtain the prediction index of the geostress while drilling; the geostress analysis module 10 can adopt the YZC6 gas extraction pipeline multi-parameter measuring instrument software (2023SR1201469), and can also refer to a downhole geostress measurement system while drilling provided by Chinese patent CN202322197718.1.

[0059] The gas over-limit warning module 12 performs gas over-limit risk identification based on the gas concentration analysis module 11 and the ground stress analysis module 10 and provides a warning result of the gas over-limit risk.

[0060] In this embodiment 1, a high-extraction tunnel 1 is used for extraction drilling. A drilling rig 9 is used from the drilling site 2 of the high-extraction tunnel 1 to construct a through-layer drill hole 5 to the recovery working face 4 arranged in the coal seam 3. The hole arrangement position is the entire recovery working face 4, including the range of 15 m outside the tunnel contour line of the two recovery working face tunnels 6 on the recovery working face 4. The hole arrangement spacing is 2R, R is the drilling extraction radius, and R is 2m in this embodiment 1.

[0061] A drilling site 2 is arranged for every 4 to 6 rows of through-layer drill holes 5, and the spacing between the drilling sites 2 is generally not more than 10 m. In this embodiment 1, one drilling site 2 is arranged for every 4 rows of through-layer drill holes 5; and a single-hole gas precision meter 7 and a drilling-while-drilling ground stress measuring instrument 8 are installed for all the through-layer drill holes 5 within the range of 3 drilling sites ahead of the current position of the coal mining machine; the single-hole gas precision meter 7 is arranged in the middle of the through-layer drill hole 5, and the drilling-while-drilling ground stress measuring instrument 8 is arranged on the mining working face 4.

[0062] The drilling rig 9 is connected to a gas over-limit warning module 12, and the gas over-limit warning module 12 is respectively connected to a ground stress analysis module 10 and a gas concentration analysis module 11, and the ground stress analysis module 10 is connected to each while-drilling ground stress measuring instrument 8, and the gas concentration analysis module 11 is connected to each single-hole gas precision meter 7, thereby obtaining gas single-hole precise metering data and ground stress while-drilling measurement data in real time while extracting gas.

[0063] The intelligent prediction method for gas over-limit in a mine recovery working face of the present invention is based on the intelligent prediction system for gas over-limit in a mine recovery working face described above, and includes a gas concentration early warning method and a ground stress measurement while drilling early warning method. The gas concentration early warning method includes the following contents:

[0064] S1. Drill holes through the coal seam in the high-drawing lanes to obtain real-time gas monitoring data of at least three drilling sites of the leading coal mining machine in the mining working face (including the 15m range outside the contour lines of the two lanes); the gas concentration range of the single-hole gas precise measurement data is 0~100%;

[0065] S2. Extract the current gas monitoring value M t Gas monitoring data for the time periods T1 and T2 before the current moment;

[0066] The time period T1 is 10 to 15 minutes; the time period T2 is determined according to the advancing speed of the working face;

[0067] S3. Based on the gas monitoring data of time period T1, the gas concentration analysis module calculates the index N t ;

[0068] Index N t is the average value of the gas monitoring data in the T1 period before the current moment, and the calculation method is:

[0069] ;

[0070] The short-term gas over-limit warning threshold N0 is the index N of the time period T1 before the current moment. t ; If the index N t If the gas level is greater than N0, a short-term warning of gas exceeding the limit will be issued for 10 to 15 minutes. Repeat this step continuously. If there are two or more short-term warnings of gas exceeding the limit, the gas electric interlock operation will be immediately implemented to cut off the power supply of the coal mining machine and stop the coal mining machine from working.

[0071] S4. Based on the gas monitoring data of time period T2, the gas concentration analysis module calculates the index P t ;

[0072] Index P t is the average value of the gas monitoring data in the T2 time period before the current moment, and the calculation method is:

[0073] ;

[0074] Among them, y i is the gas monitoring data of the working face at different times in the T2 period; v is the advancing speed of the working face; l is the advancing distance of the working face, which is generally 15~30 m;

[0075] S5. When the index N t When the gas monitoring value M is greater than the threshold value N0, a short-term gas over-limit warning is issued; t When it is greater than the threshold value M0, an emergency warning of gas exceeding the limit is issued;

[0076] The threshold M0 is the average value P of the gas monitoring data in the time period T2 before the current moment. t 200% of, that is:

[0077] ;

[0078] If M t If it is greater than M0, an emergency warning of gas over-limit will be issued, and the gas-electric interlocking operation will be immediately implemented to cut off the power supply of the coal mining machine and stop the coal mining machine from working;

[0079] S6. As the working face advances, repeat steps 1 to 5 to provide dynamic real-time warnings for excessive gas in the working face.

[0080] In Example 1, T1 is 15 minutes, T2 is 3 days, and N is calculated. t =17.8%, P t =19.55%, M t =15.1%, M0=39.1%.

[0081] The early warning of geostress measurement while drilling includes the following contents:

[0082] S1. Drill holes through the coal seam in the high-drawn lanes, obtain the ground stress monitoring data Z of at least three drilling sites of the leading coal mining machine in the mining working face (including the range of 15m outside the contour lines of the two lanes) in real time, extract the ground stress monitoring data of the coal seam roof rock layer in the time periods T1 and T2 before the current moment, and collect drill cuttings; the time period T1 is 10-15 minutes; the time period T2 is determined according to the advancement speed of the working face;

[0083] S2, as the mining face advances, step S2 is continuously repeated;

[0084] According to the ground stress monitoring data of time period T2, the in-situ ground stress α is calculated by the ground stress analysis module. t and send the above indicators to the ground for backup;

[0085] When the in-situ ground stress monitoring data Z of the rock formation to be tested is greater than the threshold value α0, an emergency warning of gas exceeding the limit is issued. After the warning is triggered, the gas electric locking operation is immediately implemented to cut off the power supply of the coal mining machine and the coal mining machine stops working; α t The calculation method of α0 is:

[0086] ;

[0087] ;

[0088] Among them, z i is the in-situ ground stress monitoring data of rock formations in different boreholes during the T2 time period; v is the working face advancement speed; l is the working face advancement distance.

[0089] In this embodiment 1, α t =12.1 MPa, α0=24.2 MPa.

[0090] During the mining process of the working face, the layout of the extraction drill holes is the entire mining working face (including the 15 m range outside the contour lines of the two tunnels). The installation position of the intelligent early warning system for excessive gas limit in this embodiment is all the through-layer drill holes within the range of 3 drilling sites ahead of the current position of the coal mining machine. When the coal mining machine advances past the drilling site, the intelligent early warning system for excessive gas limit in this embodiment can be removed and moved to the drilling site behind, so that the intelligent early warning system for excessive gas limit always covers all the through-layer drill holes within the range of 3 drilling sites ahead of the current position of the coal mining machine.

[0091] When constructing multiple high-extraction tunnels and drilling through layers to measure ground stress, the spacing between the boreholes should be large enough to avoid the construction boreholes affecting other adjacent boreholes. In order to improve the accuracy of ground stress monitoring data while drilling, experimental tests and verifications are carried out separately for different rock layers to be measured.

[0092] Embodiment 2:

[0093] See also Figure 6-Figure 9 , Figure 6 A layout diagram of the inside of a drilling site of an intelligent prediction system for gas over-limit in a mine recovery working face is drawn. As shown in the figure, the intelligent prediction system for gas over-limit in a mine recovery working face of this embodiment 2 is different from that of embodiment 1 in that:

[0094] In the present embodiment 2, a bottom extraction tunnel 13 is used for extraction drilling, and a drilling rig 9 is used from the drilling site 2 of the bottom extraction tunnel 13 to construct a through-layer drilling hole 5 toward the recovery working face 4 arranged in the coal seam 3.

[0095] Working principle:

[0096] The present invention provides an intelligent prediction system and method for gas over-limit in a mine recovery working face, which combines single-hole gas metering data with drilling ground stress data to coordinately warn of gas over-limit accidents in the recovery working face; through-layer drilling is constructed from a high-extraction lane or a bottom-extraction lane (gas pre-extraction lane) to the recovery working face, and a single-hole gas precision meter and a drilling ground stress measuring instrument are installed; the single-hole gas data and drilling ground stress data of the recovery working face are obtained in real time, and the gas over-limit threshold is fit-analyzed by a gas concentration analysis module and a ground stress analysis module and compared with the real-time monitoring data, and then the gas over-limit warning module is used to coordinately warn of gas over-limit accidents in the mine recovery working face.

[0097] The above are only specific application examples of the present invention and do not constitute any limitation on the protection scope of the present invention. Any technical solution formed by equivalent transformation or equivalent replacement shall fall within the protection scope of the present invention.

Claims

1. An intelligent prediction system for gas over-limit in a mine working face, characterized by: It comprises a data acquisition module, a gas concentration analysis module (11), a ground stress analysis module (10) and a gas over-limit early warning module (12). The data acquisition module collects precise metering data of a single gas extraction borehole and ground stress measurement data during the mining process of the working face; the gas concentration analysis module (11) and the ground stress analysis module (10) perform corresponding fitting analysis on the collected precise metering data of a single gas extraction borehole and ground stress monitoring data while drilling to obtain gas and ground stress early warning indicators; the gas over-limit early warning module (12) coordinates early warning of gas over-limit accidents during the mining process based on the fitting results; The data acquisition module is used to collect monitoring data and provide early warning basic data for other modules; the data acquisition module mainly includes a single-hole gas precision meter (7) and a drilling-while-drilling ground stress measuring instrument (8), and is connected to the corresponding analysis module through a wireless sensor; The gas concentration analysis module (11) is used to analyze the changes in the gas concentration characteristics of the mining face in real time, and to predict the gas concentration sequence of the mining face in the future, to obtain the real-time change curve of the ultra-low gas concentration, the predicted curve of the gas concentration change and the maximum value of the gas concentration that may appear in the future, and to obtain the prediction index of the gas concentration; The geostress analysis module (10) is used to analyze the change of geostress in hard and soft rocks, and calculate the in-situ geostress of soft and hard rocks by combining the output energy of the drilling machine, the amount of drill cuttings and the particle size distribution of drill cuttings during the drilling process, so as to obtain the in-situ geostress change curve and the prediction curve as well as the maximum value of the future geostress, and obtain the prediction index of geostress while drilling; The gas over-limit warning module (12) performs gas over-limit risk identification based on the gas concentration analysis module (11) and the ground stress analysis module (10), and provides a warning result of the gas over-limit risk level; The drilling rig (9) is connected to a gas over-limit warning module (12), the gas over-limit warning module (12) is respectively connected to a ground stress analysis module (10) and a gas concentration analysis module (11), the ground stress analysis module (10) is connected to each while-drilling ground stress measuring instrument (8), and the gas concentration analysis module (11) is connected to each single-hole gas precision meter (7).

2. The intelligent prediction system for gas over-limit in a mine recovery working face according to claim 1 is characterized by: Utilizing the pre-extraction tunnel extraction borehole, i.e., the upper tunnel or the lower tunnel, a drilling rig (9) is used from the drilling field (2) of the pre-extraction tunnel to construct a through-layer borehole (5) toward the recovery working face (4) arranged in the coal seam (3). The current position of the coal mining machine is ahead of all the through-layer boreholes (5) within the range of the drilling field by 3 drilling fields, and a single-hole gas precision meter (7) and a drilling-while-drilling ground stress measuring instrument (8) are installed.

3. The intelligent prediction system for gas over-limit in a mine working face according to claim 1 is characterized by: The through-layer drill holes (5) are arranged in the entire mining working face (4), including a range of 15 m outside the tunnel contour lines of two mining working face tunnels (6) on the mining working face (4).

4. The intelligent prediction system for gas over-limit in a mine recovery working face according to claim 3 is characterized by: The spacing between the through-layer drill holes (5) is 2R, where R is the drilling hole extraction radius.

5. The intelligent prediction system for gas over-limit in a mine working face according to claim 3 is characterized by: A drilling site (2) is arranged every 4 to 6 rows of through-layer boreholes (5), and the distance between each drilling site (2) does not exceed 10 m.

6. The intelligent prediction system for gas over-limit in a mine working face according to claim 3 is characterized by: The single-hole gas precision meter (7) is arranged in the middle of the through-layer borehole (5), and the drilling-while-drilling ground stress measuring instrument 8 is arranged on the mining working face (4).

7. An intelligent prediction method for gas over-limit in a mine recovery working face, based on the intelligent prediction system for gas over-limit in a mine recovery working face as described in claim 1, characterized in that: Includes the following: Step 1: Drilling and collecting data; Through-drilling is carried out in the coal seam pre-extraction tunnel to obtain the single-hole gas data and ground stress drilling data of at least three drilling sites of the leading coal mining machine in the entire mining face in real time; Step 2: extracting gas monitoring data and ground stress while drilling monitoring data; Extract the current gas monitoring value M t Extract the drilling monitoring data of the ground stress of the coal seam roof rock layer from the gas monitoring data of the time periods T1 and T2 before the current moment; Step 3: Calculate the index N t ; According to the gas monitoring data of time period T1, the gas concentration analysis module calculates the index N t ; Index N t is the average value of gas monitoring data in the T1 period before the current moment, and the index N t The calculation method is: ； Step 4: Calculate the index P t and the in-situ stress α t ; According to the gas monitoring data of time period T2, the gas concentration analysis module calculates the index P t , index P t is the average value of gas monitoring data in the time period T2 before the current moment, and the index P t The calculation method is: ； Among them, y i is the gas monitoring data of the working face at different times in the T2 period; v is the advancing speed of the working face; l is the advancing distance of the working face; According to the ground stress monitoring data of time period T2, the in-situ ground stress α is calculated by the ground stress analysis module. t , and send the above index data to the ground for backup; in-situ ground stress α t The calculation method is: ； Step 5: Determine and warn; The short-term gas over-limit warning threshold N0 is the index N of the time period T1 before the current moment. t ; The threshold M0 is the average value P of the gas monitoring data in the T2 time period before the current moment t 200% of ; The calculation method of threshold α0 is: ； Among them, z i is the in-situ ground stress monitoring data of rock formations in different boreholes during the T2 period; v is the working face advancement speed; l is the working face advancement distance; When the index N t When the gas monitoring value M is greater than the threshold value N0, the gas over-limit warning module will issue a short-term gas over-limit warning. t When it is greater than the threshold value M0, an emergency warning of gas exceeding the limit is issued; When the in-situ ground stress monitoring data Z of the rock formation to be tested is greater than the threshold value α0, an emergency warning of gas exceeding the limit is issued; after the warning is triggered, the gas-electric locking operation is immediately implemented to cut off the power supply of the coal mining machine and the coal mining machine stops working.

8. The intelligent prediction method for gas over-limit in a mine working face according to claim 7, characterized in that: The time period T1 is 10 to 15 minutes; the time period T2 is determined according to the advancement speed of the working face.

9. The intelligent prediction method for gas over-limit in a mine working face according to claim 7, characterized in that: In step 5, if the indicator N t If the gas monitoring value M is greater than N0, a short-term warning of gas exceeding the limit for 10 to 15 minutes is issued. Repeat this step continuously. If there are two or more short-term warnings of gas exceeding the limit, the gas electric interlocking operation is immediately implemented to cut off the power supply of the coal mining machine and stop the coal mining machine. If the current gas monitoring value M t If it is greater than M0, an emergency warning of gas over-limit will be issued, and the gas-electric interlocking operation will be immediately implemented to cut off the power supply of the coal mining machine and stop the coal mining machine from working.

10. The intelligent prediction method for gas over-limit in a mine working face according to claim 7, characterized in that: The gas concentration range of the single-hole gas precise metering data is 0~100%.

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