Pressure relief outburst prevention width monitoring system for coal body on coal seam goaf

Abstract

The utility model relates to the technical field of gas control, and discloses a coal body pressure relief outburst prevention width monitoring system on a coal seam goaf, which comprises a plurality of monitoring devices, a multi-channel data acquisition device and a computer terminal, and the monitoring devices are respectively arranged in stepped drill holes which are equidistantly drilled along the direction of a roadway; the monitoring device comprises a stress sensor, a floral tube, a hole sealing assembly and a pressure sensor, and the stress sensor is arranged in a coal and rock mass of a drill hole, is in communication connection with the multi-channel data acquisition equipment and is used for acquiring stress values of all drill hole positions in the coal and rock mass of a next section in real time; the floral tube is arranged in a drill hole, a hole opening is blocked by a hole sealing assembly, and the exposed end of the hole sealing assembly is provided with a pressure sensor in communication connection with the multi-channel data acquisition equipment. According to the utility model, the gas pressure and the coal rock mass stress are monitored in real time, and the computer terminal is utilized to generate a real-time change curve of the distance from the roadway, the coal rock mass stress and the gas pressure, so that the long-term dynamic monitoring of the pressure relief width of the coal seam in the next section is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to a gas control technical field especially relates to a coal seam goaf upper coal body pressure relief outburst prevention width monitoring system for the monitoring of the next section coal seam pressure relief range after the upper section coal seam is mined, and further effectively guiding the mine gas control and guaranteeing the mine safety production. BACKGROUND

[0002] The gob-side entry driving is the next section mining roadway formed by driving along the goaf or small coal pillar after the upper section mining. For the outburst coal seam, under the condition of the stability control measures of the roadway side, this roadway arrangement mode not only improves the coal resource recovery rate, but also reduces the gas control time. The pressure relief outburst prevention width influences the reliability and safety of the gob-side entry driving and is the key parameter that needs to be accurately mastered before the mining face arrangement and coal roadway driving. After the mining face mining, the goaf side coal body stress redistributes and forms the "horizontal three zones" along the mining face strike direction. The stress of the coal body in the pressure relief zone close to the goaf is lower than the original stress, the coal body is pressure relieved and transferred to the mining space, and the coal body is broken, so the pressure relief zone is called the broken stable zone from the perspective of the elastic-plastic mechanics theory. With the stress transferred to the deep coal body, the stress of the coal body gradually increases to the stress peak value, the coal body strength gradually increases, and even breaks, and this range is called the broken intense zone. The later stress is transferred to the deeper coal body and restored to the original stress state, and this range is called the elastic zone, and the broken stable zone and the broken intense zone are called the plastic zone, that is, the coal wall to the stress peak value region. The stress in the plastic zone is released for a long time, the coal seam permeability increases, the gas is continuously desorbed and released, the gas pressure is greatly reduced, and the kinetic energy of the gas disaster is gradually lost. Under the protection of the pressure relief area of the section, as long as the sufficient protection width is reserved, the outburst elimination work during the coal seam roadway driving can be realized. At the same time, many current outburst prevention measures such as deep hole loose blasting and pressure relief slot are to increase the pressure relief zone width to achieve the purpose of outburst prevention. Therefore, it can be known that accurately determining the pressure relief zone width has important significance for the rapid and safe driving and effective gas extraction.

[0003] When the pressure relief width is investigated, the drilling cutting method, the gas content method, the initial velocity method of gas emission from borehole, the gas extraction parameter method and the like approaches can be adopted. The data measured by these methods are limited by many influencing factors, the index used for investigating the pressure relief width is single, the determination result has great uncertainty, and it is difficult to dynamically investigate the influence of the coal seam in the previous section on the pressure relief width range of the coal seam in the next section during the mining process. Based on this, the coal seam goaf upper coal body pressure relief outburst width monitoring system is provided according to the related theoretical research of the pressure relief outburst width, the coal rock mass stress and the coal seam gas pressure can be dynamically monitored, the real-time distance from the roadway and the coal rock mass stress and gas pressure change curve are generated through the computer terminal, and the long-term dynamic monitoring of the pressure relief width of the coal seam in the next section is realized. Practical new type content

[0004] The coal seam goaf upper coal body pressure relief outburst width monitoring system can dynamically monitor the coal rock mass stress and the coal seam gas pressure, the real-time distance from the roadway and the coal rock mass stress and gas pressure change curve are generated through the computer terminal, and the long-term dynamic monitoring of the pressure relief width of the coal seam in the next section is realized.

[0005] The technical scheme adopted by the utility model to solve its technical problems is:

[0006] The coal seam goaf upper coal body pressure relief outburst width monitoring system comprises a plurality of monitoring devices, a multichannel data acquisition equipment in communication connection with the plurality of monitoring devices and a computer terminal in communication connection with the multichannel data acquisition equipment, each monitoring device is arranged in a stepped borehole drilled along the direction of the roadway at equal intervals, the monitoring device comprises a stress sensor, a flower tube, a hole sealing assembly and a pressure sensor, the stress sensor is arranged in the coal rock mass of the borehole and is in communication connection with the multichannel data acquisition equipment and is used for acquiring the stress value of each borehole position in the next section of coal rock mass in real time, the flower tube is arranged in the borehole, the hole is plugged by the hole sealing assembly, and a pressure sensor in communication connection with the multichannel data acquisition equipment is mounted on the exposed end of the flower tube.

[0007] In some optional embodiments, the depths of the plurality of boreholes extend to the deep part of the next section of coal seam in a stepped manner from the two ends of the roadway to the middle part.

[0008] In some optional embodiments, the pressure sensor adopts a digital display pressure sensor.

[0009] In some optional embodiments, the hole sealing assembly adopts a grouting hole sealing assembly.

[0010] In some alternative embodiments, the grouting hole sealing assembly comprises a front hole sealing bag, a rear hole sealing bag, a first grouting pipe, a grouting pipe and a grouting pump, the front hole sealing bag and the rear hole sealing bag are fixed on the flower pipe for sealing the flower pipe at the drilling hole, the first grouting pipe and the grouting pipe are bound on the flower pipe, one end of the first grouting pipe is connected with the grouting pump, the other end is communicated with the front hole sealing bag and the rear hole sealing bag, and a burst valve is arranged between the front hole sealing bag and the rear hole sealing bag, the grouting pump is used for pumping grouting liquid into the front hole sealing bag, the rear hole sealing bag and the hole section between the front hole sealing bag and the rear hole sealing bag, and the grouting pipe is communicated with the cavity between the front hole sealing bag and the rear hole sealing bag for discharging the grouting liquid.

[0011] In some alternative embodiments, the flower pipe is provided with a grouting bag at one end in the drilling hole, the stress sensor is fixed on the flower pipe and located in the grouting bag, and the flower pipe is further provided with a second grouting pipe, the exposed end of the second grouting pipe is provided with a valve, and the grouting pump is used for pumping grouting liquid into the grouting bag.

[0012] In some alternative embodiments, the grouting liquid adopts a polymer material similar to the mechanical properties of the coal rock mass.

[0013] Compared with the prior art, the utility model has the advantages of:

[0014] 1. The utility model solves the single problem of the previous unloading width investigation index, through the real-time monitoring of the gas pressure and the coal rock mass stress, the computer terminal generates the real-time distance from the roadway and the coal rock mass stress and the gas pressure change curve, first, the plastic zone is determined according to the distance from the roadway and the coal rock mass stress curve, then, the unloading width distance is determined in the plastic zone according to the distance from the roadway and the gas pressure curve, the unloading width obtained by this mode is more scientific and reliable, and the unloading width of the next section coal seam can also be long-term dynamic monitored.

[0015] 2. The stress sensor is directly used for measuring the coal rock mass stress, the problem that the indirect measurement is easily disturbed by various external factors can be overcome, and the measurement of the unloading width is more accurate in combination with the gas pressure.

[0016] 3. The monitoring system can continuously and automatically collect data without personnel, personnel only need to regularly check the on-site equipment and collect data, the number of personnel going down the well is reduced, and compared with other methods, the utility model is more safe and convenient, and the data measured by other methods is only the instantaneous data at the time, does not have continuity and influences the accuracy of the measurement result. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical scheme in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description, obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor based on these drawings.

[0018] Figure 1 is the planar arrangement drawing of the coal seam goaf upper coal body pressure relief outburst prevention width monitoring system provided by the present application;

[0019] Figure 2 is Figure 1 The structural schematic diagram of the monitoring device provided by the present application;

[0020] Figure 3 is the distance from the roadway and the coal rock mass stress and gas pressure change curve diagram generated on the computer terminal provided by the present application.

[0021] In the drawings, the component list represented by each sign is as follows:

[0022] 1 - monitoring device, 1.1 - stress sensor, 1.2 - flower pipe, 1.3 - pressure sensor, 1.4 - front hole sealing bag, 1.5 - rear hole sealing bag, 1.6 - first grouting pipe, 1.7 - grout outlet pipe, 1.8 - grouting pump, 1.9 - blasting valve, 1.10 - grouting bag, 1.11 - second grouting pipe, 1.12 - valve, 2 - multi-channel data acquisition equipment, 3 - computer terminal, 4 - drill hole. DETAILED DESCRIPTION

[0023] It should be understood that the specific embodiments described herein are merely intended to explain the present application, and are not intended to limit the present application.

[0024] The technical scheme in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application, obviously, the described embodiments are only some embodiments of the present application, and are not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0025] In the description of the present application, it should be explained that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application;

[0026] Furthermore, the terms "first," "second," etc., used in this utility model are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. The terms "installed," "connected," and "joined" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0028] Example 1

[0029] As attached Figure 1 As shown, this embodiment provides a coal seam goaf pressure relief and outburst prevention width monitoring system, including multiple monitoring devices 1, a multi-channel data acquisition device 2 that is communicatively connected to the multiple monitoring devices, and a computer terminal 3 that is communicatively connected to the multi-channel data acquisition device; each of the monitoring devices 1 is respectively installed in stepped boreholes 4 drilled at equal intervals along the roadway direction; preferably, the depth of the multiple boreholes 4 extends from both ends of the roadway to the middle in a stepped manner to the deeper part of the next section of coal seam, which can monitor coal seams at different depths. The spacing of the boreholes is determined according to the length of the roadway, generally one borehole is arranged every 2m. When drilling, after completing the predetermined depth, preliminary cleaning is carried out to ensure that there are no drill cuttings in the deep borehole, and the borehole formation effect is observed to see if it meets the standard.

[0030] As attached Figure 2 As shown, the monitoring device 1 in this embodiment includes a stress sensor 1.1, a perforated tube 1.2, a sealing assembly, and a pressure sensor 1.3. The stress sensor 1.1 is installed in the coal and rock mass of borehole 4 and is communicatively connected to a multi-channel data acquisition device 2 to acquire the stress values ​​at each borehole location in the next section of the coal and rock mass in real time. The perforated tube 1.2 is installed inside borehole 4, with its opening sealed by the sealing assembly, and its exposed end is equipped with a pressure sensor 1.3 that is communicatively connected to the multi-channel data acquisition device 2, enabling real-time monitoring of coal seam gas pressure through the pressure sensor 1.3. Preferably, the pressure sensor 1.3 is a digital display pressure sensor, which can display the gas pressure in real time underground.

[0031] The embodiment monitors the stress and gas pressure changes of the coal rock mass of the next section by stress sensors and digital pressure sensors, converts the sensor signals into signals acceptable by the computer terminal by using a multi-channel data acquisition device, and transmits the signals to the computer terminal by using Ethernet communication, and generates the curves of the distance from the roadway and the changes of the gas pressure and the stress of the coal rock mass as shown in the attached Figure 3 The distance corresponding to the time when the stress of the coal rock mass increases to the peak value and then obviously decreases is the range of the plastic zone. Then, the curve of the distance from the roadway and the gas pressure is observed, and when the gas pressure in the plastic zone is lower than 0.74 MPa specified in the regulation, the distance of the pressure relief width in the plastic zone is determined. By this way, the real-time dynamic investigation of the pressure relief width can be realized, and the investigation indexes are more comprehensive, and the results are more accurate.

[0032] Embodiment Two

[0033] On the basis of the embodiment one, the hole sealing assembly of the embodiment is preferably a grouting hole sealing assembly. As shown in the attached Figure 2 The grouting hole sealing assembly includes a front hole sealing bag 1.4, a rear hole sealing bag 1.5, a first grouting pipe 1.6, a grout discharge pipe 1.7, and a grouting pump 1.8. The front hole sealing bag 1.4 and the rear hole sealing bag 1.5 are both fixed on the flower pipe 1.2 for blocking the flower pipe at the borehole mouth. The first grouting pipe 1.6 and the grout discharge pipe 1.7 are both bound on the flower pipe 1.2. One end of the first grouting pipe 1.6 is connected to the grouting pump 1.8, and the other end communicates with the front hole sealing bag 1.4 and the rear hole sealing bag 1.5. A burst valve 1.9 is arranged between the front hole sealing bag and the rear hole sealing bag. The grouting pump is used to pump grouting liquid into the front hole sealing bag, the rear hole sealing bag, and the hole section between the front hole sealing bag and the rear hole sealing bag. The grout discharge pipe communicates with the cavity between the front hole sealing bag and the rear hole sealing bag for discharging the grouting liquid.

[0034] During the hole sealing operation, the grouting pump is started to first grout the front hole sealing bag and the rear hole sealing bag. When the grouting pressure reaches a certain value, the burst valve in the first grouting pipe opens to grout the middle section of the front hole sealing bag and the rear hole sealing bag. When the grout discharge pipe returns the grouting liquid, it indicates that the grouting of the middle section is completed. After the grouting is completed, the grouting liquid is solidified.

[0035] Embodiment Three

[0036] On the basis of the embodiment one or the embodiment two, the mounting mode of the stress sensor is optimized in the embodiment. As shown in the attached Figure 2Said, the embodiment is located in the drill hole 4 one end of the flower pipe 1.2 is equipped with grouting bag 1.10, the stress sensor 1.1 is fixed on the flower pipe 1.2 and is located in grouting bag 1.10, the flower pipe 1.2 is also equipped with second grouting pipe 1.11, the exposed end of the second grouting pipe 1.11 is equipped with valve 1.12, and the grouting pump is pumped into the grouting bag, and the grouting fluid of the embodiment is preferably similar to the mechanical property of coal rock mass Polymer material, which can make the monitoring data of the stress sensor more accurate, and can improve the long-term stability of the hole sealing.

[0037] Specific implementation, first, the grouting bag containing stress sensor at the end is grouted through the second grouting pipe, when the grouting pressure reaches the predetermined value and remains stable, the valve is closed, and after the grouting fluid is solidified, the fixing of the pressure sensor is completed, and then the hole sealing operation of the drill hole is carried out.

[0038] The above is only the embodiment of the present application, and does not limit the patent range of the present application, and any equivalent structure or equivalent process transformation using the content of the present application specification, or direct or indirect application in other related technical fields, are also included in the patent protection range of the present application.

Claims

1. A coal seam goaf coal body pressure relief outburst prevention width monitoring system, characterized in that: The monitoring device, the multi-channel data acquisition device and the computer terminal are connected in communication; Each of the monitoring devices is arranged in a stepped borehole drilled at equal intervals along the direction of the roadway; The monitoring device comprises a stress sensor, a flower tube, a hole sealing assembly and a pressure sensor, the stress sensor is arranged in the coal rock mass of the borehole and is connected in communication with the multi-channel data acquisition device, and is used for acquiring the stress value of each borehole position in the next section of coal rock mass in real time; the flower tube is arranged in the borehole, the borehole is plugged by the hole sealing assembly, and the exposed end of the flower tube is provided with the pressure sensor connected in communication with the multi-channel data acquisition device.

2. The coal seam goaf upper coal body pressure relief outburst prevention width monitoring system according to claim 1, characterized in that: The depths of the plurality of boreholes extend to the deep part of the next section of coal seam in a stepped manner from the two ends of the roadway to the middle part.

3. The coal seam goaf upper coal body pressure relief outburst prevention width monitoring system according to claim 1, characterized in that: The pressure sensor is a digital pressure sensor.

4. The coal seam goaf upper coal body pressure relief outburst prevention width monitoring system according to claim 1, characterized in that: The hole sealing assembly is a grouting hole sealing assembly.

5. The coal seam goaf upper coal body pressure relief outburst prevention width monitoring system according to claim 4, characterized in that: The grouting hole sealing assembly comprises a front hole sealing bag, a rear hole sealing bag, a first grouting pipe, a grout outlet pipe and a grouting pump, the front hole sealing bag and the rear hole sealing bag are fixed on the flower tube and are used for plugging the flower tube at the borehole opening, the first grouting pipe and the grout outlet pipe are bound on the flower tube, one end of the first grouting pipe is connected with the grouting pump, the other end communicates with the front hole sealing bag and the rear hole sealing bag, and a blasting valve is arranged between the front hole sealing bag and the rear hole sealing bag, grouting liquid is pumped into the front hole sealing bag, the rear hole sealing bag and the hole section between the front hole sealing bag and the rear hole sealing bag by the grouting pump, and the grout outlet pipe communicates with the cavity between the front hole sealing bag and the rear hole sealing bag and is used for discharging the grouting liquid.

6. The outburst prevention width monitoring system for coal seam above goaf according to any one of claims 1 to 5, characterized in that: One end of the flower tube in the borehole is provided with a grouting bag, the stress sensor is fixed on the flower tube and located in the grouting bag, and the flower tube is further provided with a second grouting pipe, the exposed end of the second grouting pipe is provided with a valve, and grouting liquid is pumped into the grouting bag by the grouting pump.

7. The coal seam goaf upper coal body pressure relief outburst prevention width monitoring system according to claim 6, characterized in that: The grouting liquid is a polymer material similar to the mechanical properties of the coal rock mass.

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