A method for positioning main fracture source of coal rock based on induced charge prediction

Abstract

The application designs a positioning method for predicting main coal rock fracture source based on induced charge, first, different surface charge monitoring probes are arranged in the coal rock charge monitoring borehole in the underground air inlet lane or air return lane; a mathematical model is established through the coal rock charge monitoring data monitored by the probe; the charge signal collected by the coal rock charge probe in real time is transmitted to the CPU software system through the transmission mode of the voltage signal for data storage and analysis; finally, the spatial coordinates of the main coal rock fracture source are determined, and the position of the main coal rock fracture of the coal rock dynamic disaster is predicted; the problems of difficult construction of the coal rock dynamic early warning method and the early warning positioning are solved, a new method is provided for the coal rock dynamic disaster early warning, the efficiency of the coal rock dynamic disaster early warning is improved, and the accuracy of the coal rock dynamic disaster early warning is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of coal mine safety and coal rock dynamic disaster prediction, and particularly relates to a positioning method for predicting a main coal rock fracture source based on induced electric charge. BACKGROUND

[0002] With the increase of global coal mining depth, coal rock dynamic disasters occur more and more frequently, and the intensity and damage degree thereof also show a gradually rising trend. Whether the coal rock dynamic disaster can be accurately predicted is of vital significance to safe and efficient production of coal mines.

[0003] At present, there are various monitoring methods for coal rock dynamic disasters, which are mainly divided into two categories. One is a conventional index prediction method, including drill cuttings, initial velocity of gas emission in a borehole and the like. These conventional indexes can reflect abnormal phenomena of gas in a mining process to a certain extent, but have obvious shortcomings, usually time-consuming and laborious, and the accuracy of prediction results is often not high, which affects efficient and high-yield production of the mine. Therefore, it is urgent to explore a reasonable and reliable technology capable of realizing accurate prediction of coal rock dynamic disasters in real time and continuously. On this basis, the second type of prediction method, i.e., an emerging geophysical method, gradually attracts attention of researchers. Commonly used geophysical monitoring methods mainly include acoustic emission monitoring, electromagnetic radiation, microseismic method and the like, but these monitoring methods mostly have low positioning accuracy and cannot accurately predict the coal rock dynamic disaster area. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application designs a positioning method for predicting a main coal rock fracture source based on induced electric charge.

[0005] A positioning method for predicting a main coal rock fracture source based on induced electric charge, specifically comprising the following steps:

[0006] Step 1: arranging electric charge monitoring probes of different faces in coal rock electric charge monitoring boreholes in an underground air intake lane or air return lane to obtain coal rock electric charge monitoring data;

[0007] In the four different face coal rock electric charge monitoring boreholes in the underground air intake lane or air return lane, coal rock electric charge monitoring probes are arranged respectively, and the spatial coordinate relative positions of the four coal rock electric charge monitoring probes are set, and the spatial coordinate relative origin is determined;

[0008] Each coal rock electric charge monitoring probe is placed at different hole depths to ensure that the four electric charge probes are not on the same spatial coordinate face; a unified clock chip is used for each coal rock electric charge monitoring probe to ensure that the received coal rock electric charge signals are synchronous; and the same filtering circuit is used for each coal rock electric charge probe to ensure that the collected coal rock electric charge signals are electric charge signals generated by the same main coal rock fracture;

[0009] Step 2: The charge signal collected by the coal rock charge probe in real time is converted into a voltage signal, which is transmitted to the CPU software system and the charge monitoring device through the transmission mode of the voltage signal for data storage, analysis and processing; the data obtained after processing is input into the equation group established in step 3 as known parameters; the charge monitoring device comprises the above-mentioned charge monitoring probe and a monitoring host; the monitoring host comprises an acquisition board, a display screen and a battery;

[0010] Step 3: An equation group is established according to the coal rock charge monitoring data monitored by the probe in step 1; and the data obtained in step 2 is taken as a known parameter to determine the spatial coordinates of the main coal rock fracture source;

[0011] Firstly, the spatial coordinates of the main coal rock fracture source are (x, y, z), the charge source generated by the main fracture is q, the spatial coordinates of the first coal rock charge probe a are (0, 0, a), the spatial coordinates of the second coal rock charge probe b are (0, b, 0), the spatial coordinates of the third coal rock charge probe c are (c, 0, 0), and the spatial coordinates of the fourth coal rock charge probe d are (0, 0, 0), then the distances r1, r2, r3 and r4 of the four coal rock charge probes from the main coal rock fracture source; specifically:

[0012]

[0013]

[0014]

[0015]

[0016] According to the principle of point charge induction measurement, the following is obtained:

[0017]

[0018]

[0019]

[0020] Wherein, C is the capacitance in the charge measuring device; Q is the charge value measured in the charge measuring device; V is the voltage value output by the charge measuring device; E is the electric field strength of the point charge source at the position of the charge measuring device; π is a constant; k is the electrostatic constant; ε is the dielectric constant; s is the opposite area of the capacitor plate; q is the charge value of the point charge source; r is the distance between the point charge source and the charge measuring device;

[0021] Thus, we get:

[0022]

[0023] The measured induced charge amount is related to charge sources q and r, formula 1-4 is brought into formula 8, and the numerical value of the spatial coordinates (x, y, z) of the main fracture source of coal rock is solved, so that the specific position of the main fracture source of coal rock is judged, and the rockburst prevention work is further guided.

[0024] The beneficial technical effects of the present application are:

[0025] A positioning method for predicting the main fracture source of coal rock based on induced charge, in the principle of science and efficiency, realizes real-time, accurate and positioning early warning of coal rock dynamic disaster, solves the problems of difficult construction and positioning of rock dynamic early warning method, and provides a new method for coal rock dynamic disaster early warning, which not only improves the efficiency of coal rock dynamic disaster early warning, but also improves the accuracy of coal rock dynamic disaster early warning. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The coal rock induced charge probe roadway layout of the embodiment of the present application;

[0027] Figure 2 The coal rock induced charge probe coal wall drilling layout of the embodiment of the present application;

[0028] Figure 3 The coal rock induced charge probe layout space coordinate schematic diagram of the embodiment of the present application;

[0029] Figure 4 The point charge induction monitoring principle diagram of the embodiment of the present application;

[0030] Wherein 101 is an air inlet lane charge monitoring probe arrangement point, 103 is an air inlet lane, 105 is an air return lane charge monitoring probe arrangement point, 107 is an air return lane, 201 is a coal rock charge monitoring probe No. 1 measuring hole, 202 is a coal rock charge monitoring probe No. 2 measuring hole, 203 is a coal rock charge monitoring probe No. 3 measuring hole, 204 is a coal rock charge monitoring probe No. 4 measuring hole, and 305 is a coal wall. DETAILED DESCRIPTION

[0031] The present application will be further described below in combination with the drawings and embodiments;

[0032] The positioning method for predicting the main fracture source of coal rock based on induced charge in the present application predicts the position of the main fracture of coal rock dynamic disaster by scientifically and reasonably arranging charge monitoring probes in front of the working face, and storing and analyzing the collected charge signals in the CPU software system through communication for data storage and analysis.

[0033] A positioning method for predicting the main fracture source of coal rock based on induced charge, specifically comprising the following steps:

[0034] Step 1: Different faces of the coal rock charge monitoring probe are arranged in the coal rock charge monitoring borehole in the intake airway or return airway of the underground mine, and coal rock charge monitoring data is obtained; a coal rock induced charge probe roadway layout is shown in Fig. 1; and a coal rock induced charge probe coal wall borehole layout is shown in Fig. 2. Figure 1 Figure 2

[0035] In the coal rock charge monitoring borehole of four different faces of the coal rock charge monitoring probe in the intake airway or return airway of the underground mine, the coal rock charge monitoring probe is arranged, and the spatial coordinate relative position of the four coal rock charge monitoring probes is set, and the spatial coordinate relative origin is determined, as shown in Fig. 3. Figure 3 A spatial coordinate arrangement diagram of the coal rock induced charge probe is shown in Fig. 4.

[0036] Each coal rock charge monitoring probe is placed at different depths to ensure that the four charge probes are not on the same spatial coordinate plane; a unified clock chip is used for each coal rock charge monitoring probe to ensure that the received coal rock charge signals are synchronized; and the same filtering circuit is used for each coal rock charge probe to ensure that the collected coal rock charge signals are the charge signals generated by the same coal rock main fracture.

[0037] Step 2: The coal rock charge signal collected by the coal rock charge probe in real time is converted into a voltage signal, which is transmitted to the CPU software system and the charge monitoring device through the transmission mode of the voltage signal for data storage, analysis and processing; the data obtained after processing is taken as a known parameter and input into the equation group established in step 3; the charge monitoring device includes the above-mentioned charge monitoring probe and a monitoring host; and the monitoring host includes an acquisition board, a display screen and a battery.

[0038] Step 3: An equation group is established according to the coal rock charge monitoring data monitored by the probe in step 1; and the data obtained in step 2 is taken as a known parameter to determine the spatial coordinates of the coal rock main fracture source; and a point charge induction monitoring principle diagram is shown in Fig. 5. Figure 4

[0039] First, the spatial coordinates of the coal rock main fracture source are set as (x, y, z), the charge source generated by the main fracture is q, the spatial coordinates of the first coal rock charge probe a are (0, 0, a), the spatial coordinates of the second coal rock charge probe b are (0, b, 0), the spatial coordinates of the third coal rock charge probe c are (c, 0, 0), and the spatial coordinates of the fourth coal rock charge probe d are (0, 0, 0), and the distances r1, r2, r3 and r4 of the four coal rock charge probes from the coal rock main fracture source are determined; specifically:

[0040]

[0041]

[0042] ​​​

[0043]

[0044] According to the principle of point charge induction measurement, we get:

[0045]

[0046]

[0047]

[0048] Wherein, C is the capacitance in the charge measurement device; Q is the measured charge value in the charge measurement device; V is the output voltage value in the charge measurement device; E is the electric field strength of the point charge source at the position of the charge measurement device; π is a constant; k is the electrostatic constant; ε is the dielectric constant; s is the opposite area of the capacitor plate; q is the charge value of the point charge source; r is the distance between the point charge source and the charge measurement device;

[0049] Thus we get:

[0050]

[0051] The measured induced charge quantity has a relationship with the charge source q and r. By bringing formula 1-4 into formula 8, the numerical value of the spatial coordinates (x, y, z) of the main fracture source of coal and rock is solved, so as to judge the specific position of the main fracture source of coal and rock, and further guide the prevention and control work of rock burst.

Claims

1. A method for locating the main fracture source in coal and rock based on induced charge prediction, characterized in that, Specifically, the following steps are included: Step 1: Arrange charge monitoring probes on different faces in the coal and rock charge monitoring boreholes in the underground intake or return airway to obtain coal and rock charge monitoring data; Step 2: The charge signal collected in real time by the coal and rock charge probe is converted into a voltage signal and transmitted to the CPU software system and charge monitoring device for data storage, analysis and processing via voltage signal transmission. The processed data is used as known parameters and input into the equation set established in Step 3. The charge monitoring device includes the charge monitoring probe and the monitoring host. The monitoring host includes a data acquisition board, a display screen and a battery. Step 3: Establish a set of equations based on the coal and rock charge monitoring data obtained by the probe in Step 1; and use the data obtained in Step 2 as known parameters to determine the spatial coordinates of the main coal and rock fracture source; Step 3 specifically involves: First, let the spatial coordinates of the main coal-rock fracture source be (x, y, z), and the charge source generated by the main fracture be q. Let the spatial coordinates of the first coal-rock charge probe be (0, 0, a), the second coal-rock charge probe be (0, b, 0), the third coal-rock charge probe be (c, 0, 0), and the fourth coal-rock charge probe be (0, 0, 0). Then, the distances of the four coal-rock charge probes from the main coal-rock fracture source are... , , , Specifically: （1） （2） （3） （4） Based on the principle of point charge induction measurement, we obtain: （5） （6） （7） Where C is the capacitance in the charge measuring device; Q is the measured charge value in the charge measuring device; and V is the output voltage value of the charge measuring device. E is the electric field strength of the point charge source at the location of the charge measuring device; π is a constant; k is the electrostatic constant; ε is the dielectric constant; s is the area of ​​the capacitor plates facing each other. Let q be the charge value of the charge source; r be the distance between the point charge source and the charge measuring device; Therefore, we get: （8） The measured induced charge and the charge value of the charge source q It is related to r. Substituting formulas (1)-(4) into formula (8), we can obtain the values ​​of the spatial coordinates (x, y, z) of the main coal and rock fracturing source, thereby determining the specific location of the main coal and rock fracturing source and further guiding the work of preventing and controlling rockburst.

2. The method for locating the main fracture source of coal and rock based on induced charge prediction according to claim 1, characterized in that, Step 1 involves arranging charge monitoring probes on different surfaces as follows: In the coal and rock charge monitoring boreholes on four different faces of the underground intake or return airway, coal and rock charge monitoring probes are arranged respectively. The spatial coordinates relative positions of these four coal and rock charge monitoring probes are set and the spatial coordinates relative to the origin are determined. A mathematical model is established based on the coal and rock charge monitoring data monitored by the probes. Each coal and rock charge monitoring probe is placed at different depths to ensure that the four charge probes are not on the same spatial coordinate plane; each coal and rock charge monitoring probe uses a unified clock chip to ensure that the received coal and rock charge signals are synchronized; each coal and rock charge probe uses the same filtering circuit to ensure that the collected coal and rock charge signals are charge signals generated by the same main coal and rock fracture.

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