A device and method for dynamically monitoring a pressure relief borehole collapse in a coal mine

Abstract

The application discloses a device for dynamically monitoring hole collapse of pressure relief drilling in a coal mine, which comprises a fixing mechanism and a measuring mechanism, the fixing mechanism comprises a fixing rod, and the fixing rod is inserted into the pressure relief drilling; the measuring mechanism comprises a power supply, wires, color-changing light-emitting diodes and annular spring rheostats, the annular spring rheostats are used for converting the pressure applied from the outside into changes in resistance values of the annular spring rheostats, a plurality of annular spring rheostats are arranged on the fixing rod at intervals, and each annular spring rheostat serves as a measuring point; each annular spring rheostat is connected with a color-changing light-emitting diode through the wires and the power supply to form a series loop, and the color-changing light-emitting diode changes color according to the current in the series loop; and the annular spring rheostats between the measuring points are connected in parallel. The device can dynamically and real-timely monitor the hole collapse in the hole, is not affected by the hole collapse of the drilling itself, has simple design principle, high operability and low cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coal mining, in particular to a device and method for dynamically monitoring the collapse of a pressure-relief borehole in a coal mine. BACKGROUND

[0002] With the increasing depth of mine exploitation, the stress of underground roadway surrounding rock is getting bigger and bigger, a large amount of deformation energy is accumulated in the surrounding rock, and the phenomenon of surrounding rock deformation instability is becoming more and more common, which causes great safety hazards to the safe mining of the mine. Controlling the deformation of surrounding rock through pressure-relief drilling technology is an important measure to reduce rock burst and prevent the instability of roadway surrounding rock. At the same time, monitoring the state change of the collapse of pressure-relief drilling in deep surrounding rock is an important means to study the effect of pressure-relief drilling technology. Therefore, it is necessary to design and develop a device for monitoring the state change of the collapse of pressure-relief drilling to realize the dynamic monitoring of the deformation of the hole diameter at different positions of the deep hole and provide deep hole diameter dynamic change data for pressure-relief drilling and roadway surrounding rock support.

[0003] A deep hole diameter change measuring device is disclosed in Chinese Utility Model Patent No. CN201820093963.4. The device makes the open rough steel needle contact the deep hole wall through the end head umbrella device, and the hole diameter size is obtained by reading the bar scale, thereby realizing the data monitoring of the hole diameter at different positions of the deep hole. The disadvantage of the device is that when measuring the hole diameter of the pressure-relief drilling in the underground roadway, once the drilling collapses, the area inside the collapsed hole cannot be measured. In addition, the device must be inserted into the pressure-relief drilling from the measurement position to realize effective reading, and the dynamic monitoring of the hole diameter of the pressure-relief drilling cannot be realized.

[0004] A novel deep hole diameter change measuring device is disclosed in Chinese Utility Model Patent No. CN201721708812.7. The measuring device includes a deformation monitoring box, an upper tooth plate, a gear, a lower tooth plate, an outer telescopic screw rod, an inner telescopic screw rod, a pointer, and a scale disc. The novel deep hole diameter change measuring device can realize the monitoring of the deformation of the hole diameter at different positions of the deep hole, but there are problems such as the area inside the collapsed hole cannot be measured, and the actual measurement of the hole diameter of the pressure-relief drilling is easily affected by the drilling collapse. SUMMARY

[0005] Based on the above technical problems, the present application provides a device and method for dynamically monitoring the collapse of a pressure-relief borehole in a coal mine.

[0006] The technical solution adopted by the present application is as follows:

[0007] A device for dynamically monitoring the collapse of a pressure-relief borehole in a coal mine includes a fixing mechanism and a measuring mechanism. The fixing mechanism includes a fixing rod, which is inserted into the pressure-relief drilling.

[0008] The measuring mechanism comprises a power supply, wires, color-changing light-emitting diodes and annular spring rheostats, the annular spring rheostats are used to convert the peripheral pressure applied into changes in their own resistance values, the annular spring rheostats are arranged in multiple and are installed at intervals on the fixed rod, and each annular spring rheostat serves as a measuring point;

[0009] The number of the color-changing light-emitting diodes is equal to that of the annular spring rheostats, each annular spring rheostat is connected in series with a color-changing light-emitting diode through the wires and the power supply to form a closed loop, and the color-changing light-emitting diode changes color according to the current size in the closed loop;

[0010] The annular spring rheostats between the measuring points are connected in parallel.

[0011] Preferably, the annular spring rheostat comprises a spiral metal strip that automatically rolls inward when pressed and a sliding metal pointer matched with the spiral metal strip, the sliding metal pointer is arranged along the radial direction of the spiral metal strip, one end of the sliding metal pointer close to the center of the spiral metal strip serves as the fixed end of the annular spring rheostat and is connected with the wires, the other end of the sliding metal pointer is in contact with the spiral metal strip, and the end head at the center of the spiral metal strip is connected with the wires to form a closed loop.

[0012] Preferably, the fixed rod is hollow, and the wires are arranged in the interior of the fixed rod.

[0013] Preferably, the fixed rod is formed by connecting a plurality of hollow rod bodies end to end, an external thread is arranged at one end of the hollow rod body, and an internal thread groove is arranged at the other end of the hollow rod body.

[0014] Preferably, the length of the hollow rod body is 20-40 cm, and the outer diameter of the hollow rod body is 3-5 cm; the hollow rod body is made of metal material.

[0015] Preferably, the diameter of the spiral metal strip is greater than the outer diameter of the hollow rod body, and the spiral metal strip is fixedly connected at the connection between adjacent hollow rod bodies.

[0016] Preferably, a control switch is arranged on each closed loop.

[0017] Preferably, the power supply, the control switch and the color-changing light-emitting diodes are arranged in a protective outer shell.

[0018] A method for dynamically monitoring the collapse of a pressure relief borehole in a coal mine, which adopts the device described above, and comprises the following steps:

[0019] A, drilling a pressure relief borehole on the roadway surrounding rock that needs to be prevented from being rushed and relieved according to the mine production requirements;

[0020] B, according to the depth of the pressure-relief borehole and the monitoring requirement, the number and position of the measuring points in the pressure-relief borehole are set; and according to the depth of the pressure-relief borehole and the number and position of the measuring points in the pressure-relief borehole, the number of hollow rods required is determined first, then the hollow rods are connected in sequence, the number of annular spring rheostats required is determined, the annular spring rheostats are fixed at corresponding positions of the hollow rods at intervals, wires are passed through the hollow rods, and the color-changing light-emitting diodes, control switches and power supplies are connected;

[0021] Each color-changing light-emitting diode is connected in series with an annular spring rheostat to form a closed loop of a measuring point in a hole, and the closed loops of the measuring points in the hole are connected in parallel;

[0022] After the measuring mechanism is connected, the fixing rod of the fixing mechanism is inserted into the pressure-relief borehole;

[0023] C, the control switch is turned on, the closed loop of the measuring point in the hole is conducted, then the color change of the color-changing light-emitting diode corresponding to each measuring point in the process of coal mining is recorded in real time, the resistance value change of the annular spring rheostat can be judged according to the color change of the color-changing light-emitting diode, and then the hole collapse change of the pressure-relief borehole at the measuring point can be inferred.

[0024] Preferably, according to the hole collapse change of the pressure-relief borehole at the measuring point, the downhole anti-collision technical measures are adjusted and optimized.

[0025] The beneficial technical effects of the present application are:

[0026] The present application utilizes the Ampere's theorem in electricity, cooperates the color-changing light-emitting diode with the annular spring rheostat to form a closed loop, judges the resistance value change of the annular spring rheostat through the color change of the color-changing light-emitting diode, and then infers the hole collapse change of the pressure-relief borehole at the measuring point, which provides an effective reference for optimizing the downhole anti-collision technical measures.

[0027] The present application has the advantages of simple design principle, strong operability, low cost, and greatly facilitates the measurement process of the hole diameter change of the roadway surrounding rock pressure-relief borehole. Through the present application, the work load of the downhole measurement personnel can be reduced, the hole collapse of the hole can be dynamically and real-timely monitored by inserting the fixing rod, and the present application is not affected by the hole collapse of the borehole itself. The present application can also improve the accuracy of the damage monitoring of the roadway surrounding rock pressure-relief borehole, and has obvious significance for the safe mining of coal. BRIEF DESCRIPTION OF DRAWINGS

[0028] The present application will be further described below in combination with the drawings and specific embodiments:

[0029] Figure 1 The structure principle schematic view of the dynamic monitoring coal mine pressure-relief borehole hole collapse device of the present application;

[0030] Figure 2 This is a schematic diagram illustrating the structural principle of the annular spring rheostat in the dynamic monitoring device for coal mine pressure relief borehole collapse according to the present invention.

[0031] Figure 3 This is a schematic diagram illustrating the circuit connection principle of the color-changing light-emitting diode and the ring spring rheostat in the dynamic monitoring device for coal mine pressure relief borehole collapse according to the present invention.

[0032] Figure 4 This is a schematic diagram illustrating the structural principle of the dynamic monitoring device for coal mine pressure relief borehole collapse, as described in this invention, arranged within the pressure relief borehole.

[0033] Figure 5 This is a schematic diagram of the process for dynamically monitoring the collapse of pressure-relief boreholes in coal mines according to the present invention.

[0034] In the diagram: 1-ring spring rheostat; 2-fixed rod; 3-wire; 4-measuring mechanism; 5-anchor bolt; 6-pressure relief borehole; 7-fixing mechanism; 8-surrounding rock of the tunnel; 9-spiral metal strip; 10-sliding metal pointer; 11-power supply; 12-color-changing light-emitting diode; 13-control switch. Detailed Implementation

[0035] Referring to the accompanying drawings, a device for dynamically monitoring the collapse of pressure-relief boreholes in coal mines includes a fixing mechanism 7 and a measuring mechanism 4. The fixing mechanism 7 includes a fixing rod 2, which is inserted into the pressure-relief borehole 6. The measuring mechanism 4 includes a power supply 11, wires 3, color-changing LEDs 12, and a ring spring rheostat 1. The ring spring rheostat 1 is used to convert the applied external pressure into a change in its own resistance value. Multiple ring spring rheostats 1 are arranged and spaced apart on the fixing rod 2, with each ring spring rheostat 1 serving as a measuring point. The number of color-changing LEDs 12 is equal to the number of ring spring rheostats 1, and each ring spring rheostat 1 corresponds to one color-changing LED 12, forming a series circuit between the wires 3 and the power supply 11. Figure 3 As shown, the color-changing LED 12 changes color according to the magnitude of the current in the series circuit. The ring spring rheostats 1 between each measuring point are connected in parallel.

[0036] As a further design of the present invention, such as Figure 2 As shown, the annular spring rheostat 1 includes a helical metal strip 9 and a sliding metal pointer 10 that cooperates with the helical metal strip 9. The sliding metal pointer 10 is arranged radially along the helical metal strip 9. Figure 2Only lateral principle view is given. The spiral metal strip 9 will automatically coil inwards when compressed, and the coiling degree is positively related to the size of the peripheral pressure. The end of the sliding metal pointer 10 close to the center of the spiral metal strip 9 serves as the fixed end of the ring-shaped spring rheostat 1, and is connected with the wire 3, and the other end of the sliding metal pointer 10 is in contact with the spiral metal strip 9, and the end head at the center of the spiral metal strip 9 is connected with the wire 3, forming a closed loop. When the spiral metal strip 9 is compressed by the external pressure, the resistance value of the spiral metal strip 9 in series in the closed loop increases, and the current in the loop decreases, and correspondingly the color of the color-changing light emitting diode 12 changes. That is, the resistance value of the region can be adjusted by applying pressure to the periphery of the ring-shaped spring rheostat 1, and each ring-shaped spring rheostat serves as a measuring point.

[0037] Further, the fixed rod member 2 is internally hollow, and the wire 3 is arranged inside the fixed rod member 2. The fixed rod member 2 is formed by connecting a plurality of hollow rod bodies end to end, and an external thread is arranged at one end of the hollow rod body, and an internal thread groove is arranged at the other end of the hollow rod body, and the adjacent hollow rod bodies are detachably connected by threads.

[0038] The length of the above-mentioned hollow rod body is 20-40 cm, and the outer diameter is 3-5 cm; the hollow rod body is made of metal material. Of course, the hollow rod body can also be made of deformed material. The diameter of the spiral metal strip 9 is greater than the outer diameter of the hollow rod body, and the outermost side of the spiral metal strip 9 can be simply regarded as a circle, and the diameter is generally 1-2 cm greater than the outer diameter of the hollow rod body. The width of the spiral metal strip 9 can be set to 5-10 cm, and it is arranged along the length direction of the hollow rod body. The spiral metal strip 9 is fixedly connected at the connection of the adjacent hollow rod bodies, that is, the spiral metal strip 9 can be connected and fixed with the hollow rod body at the connection of the adjacent hollow rod bodies. Of course, the spiral metal strip 9 can also be fixed with the hollow rod body in other ways, such as the spiral metal strip 9 can be sleeved on the hollow rod body, and a cut is arranged on the hollow rod body to facilitate the insertion of the end of the spiral metal strip 9 into the inside of the hollow rod body and the connection with the wire.

[0039] Further, a control switch is arranged on each closed loop. Of course, one control switch 13 can also be arranged on the total loop in parallel with a plurality of closed loops to perform total control, as shown in Figure 3

[0040] Further, the power supply 11, the control switch 13 and the color-changing light emitting diode 12 are all placed in the outer package, which can provide protection to prevent the destruction of electronic components caused by downhole operation.

[0041] ​The power supply uses a common dry battery to provide power. The switch and wire are common standard electronic components. The color-changing light-emitting diode changes color according to the current in the circuit. Each color-changing light-emitting diode is connected in series with a ring-shaped spring rheostat to form a borehole measuring point. The measuring points are connected in parallel.

[0042] It should be noted that the device needs to be installed at the end of drilling the pressure relief borehole. If the drilling time and the installation time of the device are too long, the device may not be able to reach the bottom of the borehole.

[0043] As shown in Figure 5 A method for dynamically monitoring the collapse of a coal mine pressure relief borehole, using the device described above, includes the following steps:

[0044] A. According to the mine production requirements, drill a pressure relief borehole 6 in the roadway surrounding rock where the anti-scouring pressure relief is needed. The roadway surrounding rock 8 is also anchored with an anchor rod 5, as shown in Figure 4 .

[0045] B. According to the depth of the pressure relief borehole and the monitoring requirements, set the number and position of the pressure relief borehole measuring points. According to the depth of the pressure relief borehole and the number and position of the pressure relief borehole measuring points, first determine the number of hollow rods needed, then connect the hollow rods in sequence, and then determine the number of ring-shaped spring rheostats 1 needed. The ring-shaped spring rheostats 1 are fixed at the corresponding positions of the hollow rods, and the wires 3 pass through the inside of the hollow rods and are connected to the color-changing light-emitting diodes 12, the control switch 13, and the power supply 11.

[0046] Each color-changing light-emitting diode 12 is connected in series with a ring-shaped spring rheostat 1 to form a borehole measuring point closed loop. The borehole measuring point closed loops are connected in parallel.

[0047] After the measuring mechanism is connected, the fixing rod 2 of the fixing mechanism is inserted into the pressure relief borehole 6.

[0048] C. Turn on the control switch 13, and the borehole measuring point closed loop is turned on. Then, record the color change of the color-changing light-emitting diode 12 corresponding to each measuring point in real time during the coal mining process. According to the color change of the color-changing light-emitting diode 12, the resistance value change of the ring-shaped spring rheostat 1 can be determined, and the collapse change of the pressure relief borehole 6 at the measuring point can be inferred.

[0049] In the above method, according to the collapse change of the pressure relief borehole at the measuring point, the underground anti-scouring technical measures are adjusted and optimized.

[0050] The parts not mentioned in the above method can be implemented by adopting or referring to existing technologies.

[0051] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

1. A device for dynamically monitoring borehole collapse in coal mine pressure relief drill holes, characterized in that: It includes a fixing mechanism and a measuring mechanism. The fixing mechanism includes a fixing rod that is inserted into the pressure relief borehole. The measuring mechanism includes a power supply, wires, color-changing light-emitting diodes, and ring spring rheostats. The ring spring rheostats are used to convert the pressure applied by the external environment into a change in their own resistance value. Multiple ring spring rheostats are set and installed at intervals on the fixed rod. Each ring spring rheostat serves as a measuring point. The number of color-changing LEDs is equal to the number of ring spring rheostats. Each ring spring rheostat corresponds to one color-changing LED and forms a series circuit with the power supply through a wire. The color-changing LED changes color according to the magnitude of the current in the series circuit. The ring spring rheostats between each measuring point are connected in parallel circuit. The ring spring rheostat includes a spiral metal strip that automatically rolls inward when compressed and a sliding metal pointer that cooperates with the spiral metal strip. The sliding metal pointer is arranged radially along the spiral metal strip. One end of the sliding metal pointer near the center of the spiral metal strip serves as the fixed end of the ring spring rheostat, which is connected to a wire. The other end of the sliding metal pointer contacts the spiral metal strip, and the end at the center of the spiral metal strip is connected to a wire, forming a closed circuit.

2. The device for dynamically monitoring borehole collapse in coal mine pressure relief drill holes according to claim 1, characterized in that: The fixed rod is hollow inside, and the wire is arranged inside the fixed rod.

3. The device for dynamically monitoring borehole collapse in coal mine pressure relief drill holes according to claim 1, characterized in that: The fixing member is formed by connecting several hollow rods end to end. One end of the hollow rod is provided with an external thread, and the other end of the hollow rod is provided with an internal thread groove.

4. The device for dynamically monitoring borehole collapse in coal mine pressure relief drill holes according to claim 3, characterized in that: The hollow rod has a length of 20-40cm and an outer diameter of 3-5cm; the hollow rod is made of metal material.

5. The device for dynamically monitoring borehole collapse in coal mine pressure relief drill holes according to claim 3, characterized in that: The diameter of the spiral metal strip is larger than the outer diameter of the hollow rod, and the spiral metal strip is fixedly connected to the connection of adjacent hollow rods.

6. The device for dynamically monitoring borehole collapse in coal mine pressure relief drill holes according to claim 1, characterized in that: A control switch is installed on each closed loop.

7. The device for dynamically monitoring borehole collapse in coal mine pressure relief drill holes according to claim 6, characterized in that: The power supply, control switch, and color-changing LED are all housed within a protective outer casing.

8. A method for dynamically monitoring borehole collapse in coal mine pressure relief drill holes, employing the apparatus described in any one of claims 1-7, characterized in that... Includes the following steps: A. Drill pressure relief boreholes in the surrounding rock of roadways where anti-scour and pressure relief measures are required, according to the mine production requirements; B. Based on the depth of the pressure relief borehole and the monitoring requirements, determine the number and location of the measuring points inside the pressure relief borehole; and based on the depth of the pressure relief borehole and the number and location of the measuring points inside the pressure relief borehole, first determine the required number of hollow rods, then connect the hollow rods in sequence, then determine the required number of ring spring rheostats, fix the ring spring rheostats at intervals in the corresponding positions of the hollow rods, and pass wires through the inside of the hollow rods to connect color-changing LEDs, control switches and power supplies; Each color-changing LED is connected in series with a ring spring rheostat to form a closed loop for measuring points inside the hole. The closed loops of each measuring point inside the hole are connected in parallel. After the measuring mechanism is connected, insert the fixing rod of the fixing mechanism into the pressure relief drill hole; C. Turn on the control switch to activate the closed circuit of the measuring point inside the hole. Then, record the color change of the color-changing LED at each measuring point in real time during the coal seam mining process. Based on the color change of the color-changing LED, the resistance value change of the ring spring rheostat can be determined, and then the collapse change of the pressure relief borehole at the measuring point can be inferred.

9. A method for dynamically monitoring borehole collapse in coal mine pressure relief drill holes according to claim 8, characterized in that: Based on the changes in borehole collapse at the measuring points, adjust and optimize downhole anti-blowout technology measures.

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