Potential testing device and method for impact loading process of coal containing gas

Abstract

The invention belongs to the field of coal mines, and provides a gas-containing coal impact loading process potential testing device and method.The gas-containing coal impact loading process potential testing device comprises a testing bin and an impact loading component, a coal sample is fixed in the testing bin, and the impact loading component is connected with the two ends of the coal sample and used for providing impact force for the coal sample; the impact loading component comprises an impact loading device, an incident rod and a transmission rod, the incident rod and the transmission rod are connected with the two ends of the coal sample, the coal sample is clamped in the test bin, the transmission rod is fixedly connected with the side wall of the test bin, the incident rod penetrates through the side wall of the test bin and is in sliding connection with the test bin, and the impact loading device is located outside the test bin. The impact loading device impacts the incident rod, so that the incident rod and the transmission rod mutually extrude the coal sample, and the incident rod and the transmission rod are insulating rods, so that the influence on charge change when the coal sample is impacted is prevented. The influence of external factors on the potential data change of the coal sample in the testing process can be reduced.

Description

Technical Field

[0001] The invention belongs to the field of coal mines, and in particular relates to a device and method for testing the potential of gas-containing coal during impact loading. Background Art

[0002] As the depth of coal mining continues to increase, the complex geological environment seriously threatens the stable development of underground projects, which are generally affected by impact loads such as earthquakes, mining disturbances, and blasting. In recent years, with the use of geophysical testing methods, a large number of tests and studies have been conducted on the deformation and fracture process of coal bodies under different loading modes. Studies have shown that the instability of coal bodies often produces free charges and significant potential signals on the surface of the coal bodies. By capturing abnormal potential fluctuations, the stress state and damage of coal can be characterized in real time, reflecting its internal structure and deformation state, and realizing effective monitoring of the deformation and destruction process to avoid safety accidents.

[0003] At present, the test device adopts a test cylinder, a potential collector, a vacuum pump, a high-pressure gas cylinder and an impact loading mechanism. The test sample is placed in the test cylinder, the test cylinder is evacuated by a vacuum pump, and then gas is filled into the test cylinder through a high-pressure gas cylinder. The impact force is applied to the sample through the impact loading mechanism, and finally the potential data at both ends of the sample is collected through the potential collector. However, the coal sample of the test device is in direct contact with the test cylinder and the impact loading component. Since the test cylinder and the impact loading component are made of metal or alloy materials, the metal or alloy materials are conductive and will affect the charge change of the coal sample when it is impacted, resulting in errors in the tested voltage data. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a device and method for testing the potential of gas-containing coal during impact loading, which can reduce the impact of external factors on the potential data changes of coal samples during the test process.

[0005] The technical solution of the present invention includes a test chamber and an impact loading component, the coal sample is fixed inside the test chamber, and the impact loading component is connected to both ends of the coal sample to provide impact force to the coal sample;

[0006] The impact loading component includes an impact loading device, an incident rod and a transmission rod. The incident rod and the transmission rod are connected to two ends of the coal sample to clamp the coal sample in a test chamber. The transmission rod is fixedly connected to the side wall of the test chamber. The incident rod passes through the side wall of the test chamber and is slidably connected to the test chamber. The impact loading device is located outside the test chamber. The impact loading device impacts the incident rod so that the incident rod and the transmission rod squeeze the coal sample against each other. Both the incident rod and the transmission rod are insulating rods to prevent the charge change of the coal sample from being affected when it is impacted.

[0007] Furthermore, the impact loading component also includes two insulating anti-skid layers, which are respectively located on the opposite end surfaces of the incident rod and the transmission rod, and the two insulating anti-skid layers prevent the incident rod and the transmission rod from deviating when they collide.

[0008] Furthermore, it also includes a sealed chamber, which surrounds the coal sample to keep the coal sample in a sealed environment. A shielding layer is provided on the inner wall of the sealed chamber to prevent external electromagnetic interference with the charge on the coal sample. The incident rod and the transmission rod pass through the two side walls of the sealed chamber to clamp the coal sample.

[0009] Furthermore, the shielding layer is at least one layer of copper mesh.

[0010] Furthermore, it also includes a gas filling and deflation component, which is connected to the sealed chamber and is used to evacuate the sealed chamber and fill the sealed chamber with gas. The gas filling and deflation component includes a gas cylinder, an air inlet pipe, an air outlet pipe, a vacuum pump, a second valve and a third valve. One end of the air inlet pipe and one end of the air outlet pipe are both connected to the sealed chamber, and the other end of the air inlet pipe is connected to the gas cylinder. The second valve is arranged on the air inlet pipe, and the other end of the air outlet pipe is connected to the vacuum pump. The third valve is arranged on the air outlet pipe.

[0011] Furthermore, it also includes a potential collection component, which is in contact with both ends of the coal sample to detect the potential signal when the coal sample is impacted. The potential collection component includes two electrode sheets and a potential collector. The potential collector is arranged outside the sealed chamber. The two electrode sheets are in contact with both ends of the coal sample, and the two electrode sheets are connected to the potential collector through wires.

[0012] Furthermore, a front-end amplifier is provided between the two electrode sheets and the potential collector for amplifying the voltage signal.

[0013] The present invention also provides a method for testing the potential of gas-containing coal during impact loading, comprising the following steps:

[0014] S100: The transmission rod is fixedly connected to the side wall of the test chamber, the incident rod passes through the side wall of the test chamber and is slidably connected to the test chamber, and the incident rod and the transmission rod are clamped with the coal sample inside the test chamber.

[0015] S200: After evacuating the test chamber, let it stand for at least 2 hours, then fill the test chamber with gas to make the gas pressure in the test chamber between 0.2MPa and 1MPa, and maintain it for at least 12 hours to allow the coal sample to fully absorb the gas.

[0016] S300: Stop charging gas into the test chamber, then start to continuously collect and store the voltage signals at both ends of the coal sample, and the impact loading device provides an impact force to the incident rod so that the incident rod and the transmission rod squeeze the coal sample against each other.

[0017] The technical solution provided by the embodiment of the present invention has the following advantages compared with the prior art:

[0018] The potential testing device for the impact loading process of gas-containing coal provided by the present invention clamps the coal sample inside the test chamber by an incident rod and a transmission rod, the transmission rod is fixedly connected to the side wall of the test chamber, the incident rod passes through the side wall of the test chamber and is slidably connected to the test chamber, the impact loading device is located outside the test chamber, and the impact loading device impacts the incident rod so that the incident rod and the transmission rod squeeze the coal sample against each other, avoiding the coal sample from contacting the test chamber and the impact loading device, and avoiding affecting the charge change of the coal sample when it is impacted, so as to accurately detect the voltage change of the coal sample when it is impacted, and effectively monitor the internal structure and deformation state of the coal sample.

[0019] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 This is a schematic diagram of the structure of a potential testing device according to one embodiment of the present invention.

[0022] Figure 2 for Figure 1 Sectional view of the AA section.

[0023] Reference numerals:

[0024] 1. Test bench; 2. Test chamber; 3. Incident rod; 4. Transmission rod; 5. Sealed chamber; 6. Insulation and anti-skid layer; 7. Coal sample; 8. Electrode sheet; 9. Signal receiver; 10. Potential collector; 11. Front-end amplifier; 12. Wire; 13. Shielding layer; 14. Gas collection pipe; 15. First valve; 16. Flow meter; 17. Data collector; 18. Gas cylinder; 19. Inlet pipe; 20. Outlet pipe; 21. Vacuum pump; 22. Second valve; 23. Third valve. DETAILED DESCRIPTION

[0025] A specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation.

[0026] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the technical solutions of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0027] In the description of the embodiments of the present invention, unless otherwise specified, “plurality” means two or more.

[0028] like Figure 1 and Figure 2 As shown, the present invention provides a potential testing device for the impact loading process of gas-containing coal, including a test chamber 2 and an impact loading component, a coal sample 7 is fixed inside the test chamber 2, the impact loading component is connected to both ends of the coal sample 7, and is used to provide impact force to the coal sample 7, the impact loading component includes an impact loading device, an incident rod 3 and a transmission rod 4, the incident rod 3 and the transmission rod 4 are connected to both ends of the coal sample 7, the coal sample 7 is clamped in the test chamber 2, the transmission rod 4 is fixedly connected to the side wall of the test chamber 2, the incident rod 3 passes through the side wall of the test chamber 2 and is slidably connected to the test chamber 2, the impact loading device is located outside the test chamber 2, the impact loading device impacts the incident rod 3, so that the incident rod 3 and the transmission rod 4 squeeze the coal sample 7 against each other, wherein the incident rod 3 and the transmission rod 4 are both insulating rods to prevent the charge change of the coal sample 7 from being affected when it is impacted.

[0029] The potential testing device for the impact loading process of gas-containing coal provided by the present invention clamps the coal sample 7 inside the test chamber 2 through the incident rod 3 and the transmission rod 4, the transmission rod 4 is fixedly connected to the side wall of the test chamber 2, the incident rod 3 passes through the side wall of the test chamber 2 and is slidably connected to the test chamber 2, the impact loading device is located outside the test chamber 2, and the impact loading device impacts the incident rod 3, so that the incident rod 3 and the transmission rod 4 squeeze the coal sample 7 against each other, avoiding the coal sample 7 from contacting the test chamber 2 and the impact loading device, and avoiding the influence on the charge change of the coal sample 7 when it is impacted. The potential signal of the coal sample 7 can truly reflect its stress state and damage under the coupling of gas and impact, accurately capture the potential abnormal signal of the coal sample 7 in the deformation and destruction process, effectively monitor the internal structure and deformation state of the coal sample 7, avoid safety accidents caused by data errors, and ensure the safe and stable development of coal mines.

[0030] Optionally, the test chamber 2 is fixed on the test bench 1 to ensure the stability of the test device during testing.

[0031] In the embodiment provided by the present invention, the impact loading component also includes two insulating anti-slip layers 6, and the two insulating anti-slip layers 6 are respectively located on the opposite end faces of the incident rod 3 and the transmission rod 4. The two insulating anti-slip layers 6 prevent the incident rod 3 and the transmission rod 4 from being offset when they collide, and can further prevent the impact on the charge change of the coal sample 7 when it is impacted.

[0032] In the embodiment provided by the present invention, it also includes a sealed chamber 5, which surrounds the coal sample 7 so that the coal sample 7 is in a sealed environment. A shielding layer 13 is provided on the inner wall of the sealed chamber 5 to prevent external electromagnetic interference from the charge on the coal sample 7. The incident rod 3 and the transmission rod 4 pass through the two side walls of the sealed chamber to clamp the coal sample 7.

[0033] In the embodiment provided by the present invention, a gas filling and deflation assembly is also included, which is connected to the sealed chamber 5 and is used to evacuate the sealed chamber 5 and fill the sealed chamber 5 with gas. The gas filling and deflation assembly includes a gas cylinder 18, an air inlet pipe 19, an air outlet pipe 20, a vacuum pump 21, a second valve 22 and a third valve 23. One end of the air inlet pipe 19 and one end of the air outlet pipe 20 are both connected to the sealed chamber 5, and the other end of the air inlet pipe 19 is connected to the gas cylinder 18. The second valve 22 is arranged on the air inlet pipe 19, and the other end of the air outlet pipe 20 is connected to the vacuum pump 21. The third valve 23 is arranged on the air outlet pipe 20.

[0034] It can be understood that the function of the gas filling and deflation assembly is to make the sealed chamber 5 a vacuum, and then fill the sealed chamber 5 with gas so that the coal sample 7 can fully absorb the gas and simulate the real state of the coal body.

[0035] Furthermore, in the embodiment provided by the present invention, the sealing chamber 5 includes a sealing sleeve, an oil pipe, an oil cylinder, a first valve 15 and a hydraulic pump. The wall of the sealing sleeve is a hollow structure. One end of the oil pipe passes through the test chamber 2 and is connected to the wall of the sealing sleeve, and the other end is connected to the oil cylinder, which is used to inject oil into the sealing sleeve so that the sealing sleeve squeezes the injection rod 3 and the transmission rod 4 to form a sealed chamber. The hydraulic pump is connected to the oil cylinder to control the air pressure in the oil cylinder.

[0036] In the embodiment provided by the present invention, the shielding layer 13 is at least one layer of copper mesh. The specific number of copper mesh layers or the thickness of the shielding layer 13 can be set by those skilled in the art according to their needs, and the present invention does not limit this.

[0037] In the embodiment provided by the present invention, it also includes a potential collection component, which is in contact with both ends of the coal sample 7 to detect the potential signal when the coal sample 7 is impacted. The potential collection component includes two electrode sheets 8 and a potential collector 10. The potential collector 10 is arranged outside the sealed chamber 5. The two electrode sheets 8 are in contact with both ends of the coal sample 7. The two electrode sheets 8 are connected to the potential collector 10 through wires 12.

[0038] It can be understood that the potential acquisition component is used to collect voltage signals at both ends of the coal sample 7, and to reflect the internal structure and deformation state of the coal body by measuring the change in the potential in the coal sample 7, thereby achieving effective monitoring of the deformation and destruction process of the coal body.

[0039] In the embodiment provided by the present invention, a front-end amplifier 11 is provided between the two electrode sheets 8 and the potential collector 10 for amplifying the voltage signal.

[0040] It can be understood that the voltage difference generated when the coal sample 7 is impacted is relatively low, and the voltage difference needs to be amplified, so the preamplifier 11 is provided to amplify the voltage signal.

[0041] Furthermore, a signal receiver 9 is provided between the two electrode sheets 8 and the potential collector 10 to collect voltage information of the two electrode sheets 8 .

[0042] Furthermore, in the embodiment provided by the present invention, a data acquisition component is also included for monitoring the gas emission of the coal sample 7. The data acquisition component includes a gas collection pipe 14, a first valve 15, a flow meter 16 and a data acquisition instrument 17. One end of the gas collection pipe 14 passes through the test chamber 2 and is connected to the sealing chamber 5, and the other end is connected to the data acquisition instrument 17. The first valve 15 and the flow meter 16 are both arranged on the gas pipe.

[0043] It can be understood that by collecting the gas changes in the sealed chamber 5 through the data acquisition instrument 17, it is clear that when the potential acquisition instrument 10 collects the voltage signal of the coal sample 7 being impacted, the gas changes in the sealed chamber 5 can be further improved in safety.

[0044] The present invention also provides a method for testing the potential of gas-containing coal during impact loading, comprising the following steps:

[0045] S100: The transmission rod 4 is fixedly connected to the side wall of the test chamber 2, the incident rod 3 passes through the side wall of the test chamber 2 and is slidably connected to the test chamber 2, and the incident rod 3 and the transmission rod 4 are clamped with the coal sample 7 inside the test chamber 2;

[0046] S200: the test chamber 2 is evacuated to a vacuum state and then left to stand for at least 15 minutes, and then gas is charged into the test chamber 2 to make the gas pressure in the test chamber 2 between 0.2 MPa and 1 MPa, and maintained for at least 15 minutes, so that the coal sample 7 can fully absorb the gas;

[0047] S300: Stop charging gas into the test chamber 2, then start to continuously collect and store the voltage signals at both ends of the coal sample 7, and the impact loading device provides an impact force to the incident rod 3 so that the incident rod 3 and the transmission rod 4 squeeze the coal sample 7 against each other.

[0048] Specifically:

[0049] Assemble the test device, clamp the coal sample 7 in the sealed chamber 5 through the incident rod 3 and the transmission rod 4, place two electrode sheets 8 at both ends of the coal sample 7, and connect them to the signal receiver 9 and the potential collector 10 in sequence.

[0050] The sealed chamber 5 is evacuated by the vacuum pump 21, the third valve 23 is closed, and then gas is filled into the sealed chamber 5 through the gas cylinder 18, so that the gas pressure in the sealed chamber 5 is between 0.2MPa and 1MPa, and maintained for at least hours to allow the coal sample 7 to fully absorb the gas.

[0051] After the coal sample 7 finishes absorbing gas, the gas cylinder 18 and the second valve 22 are closed, the data acquisition instrument 17 starts to continuously collect and store the gas emission of the coal sample 7, and the potential acquisition instrument 10 starts to continuously collect and store the voltage signal at both ends of the coal sample 7.

[0052] The impact loading test is started by using an impact loading device to impact the incident rod 3 to generate stress wave force acting on the coal sample 7.

[0053] After the impact loading test is completed, the data acquisition instrument 17 and the potential acquisition instrument 10 are turned off, the vacuum pump 21 and the gas outlet pipe 20 are separated, the third valve 23 is opened, the gas in the sealed chamber 5 is released and harmlessly treated, the coal sample 7 is taken out and retained, and finally the test device is dismantled.

[0054] It should be noted that the impact loading device belongs to the prior art and will not be elaborated in detail in the present invention.

[0055] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0056] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A device for testing the potential of gas-containing coal during impact loading, characterized in that: It comprises a test chamber (2) and an impact loading component, wherein a coal sample (7) is fixed inside the test chamber (2), and the impact loading component is connected to both ends of the coal sample (7) and is used to provide an impact force to the coal sample (7); The impact loading component comprises an impact loading device, an incident rod (3) and a transmission rod (4); the incident rod (3) and the transmission rod (4) are connected to two ends of a coal sample (7) to clamp the coal sample (7) in the test chamber (2); the transmission rod (4) is fixedly connected to the side wall of the test chamber (2); the incident rod (3) passes through the side wall of the test chamber (2) and is slidably connected to the test chamber (2); the impact loading device is located outside the test chamber (2); the impact loading device impacts the incident rod (3) so that the incident rod (3) and the transmission rod (4) mutually squeeze the coal sample (7); wherein the incident rod (3) and the transmission rod (4) are both insulating rods to prevent the charge change of the coal sample (7) from being affected when the coal sample (7) is impacted.

2. A potential testing device for impact loading process of gas-containing coal according to claim 1, characterized in that: The impact loading component further comprises two insulating anti-slip layers (6), the two insulating anti-slip layers (6) being respectively located on the opposite end faces of the incident rod (3) and the transmission rod (4), and the two insulating anti-slip layers (6) preventing the incident rod (3) and the transmission rod (4) from deflecting when they collide.

3. A device for testing the potential of gas-containing coal during impact loading as claimed in claim 1, characterized in that: It also includes a sealed chamber (5), the sealed chamber (5) surrounds the coal sample (7) so that the coal sample (7) is in a sealed environment, and a shielding layer (13) is provided on the inner wall of the sealed chamber (5) to prevent external electromagnetic interference with the charge on the coal sample (7); The incident rod (3) and the transmission rod (4) pass through two side walls of the sealed cabin to clamp the coal sample (7).

4. A potential testing device for gas-containing coal impact loading process as claimed in claim 3, characterized in that: The shielding layer (13) is at least one layer of copper mesh.

5. The device for testing the potential of gas-containing coal during impact loading as claimed in claim 3, characterized in that: It also comprises a gas charging and discharging assembly, which is in communication with the sealed chamber (5) and is used to evacuate the sealed chamber (5) and to charge the sealed chamber (5) with gas; The gas filling and discharging assembly comprises a gas cylinder (18), an air inlet pipe (19), an air outlet pipe (20), a vacuum pump (21), a second valve (22) and a third valve (23); one end of the air inlet pipe (19) and one end of the air outlet pipe (20) are both in communication with the sealed chamber (5); the other end of the air inlet pipe (19) is connected to the gas cylinder (18); the second valve (22) is arranged on the air inlet pipe (19); the other end of the air outlet pipe (20) is connected to the vacuum pump (21); and the third valve (23) is arranged on the air outlet pipe (20).

6. A device for testing the potential of gas-containing coal during impact loading as claimed in claim 1, characterized in that: It also includes a potential collection component, which is in contact with both ends of the coal sample (7) to detect a potential signal when the coal sample (7) is impacted; The potential collection component comprises two electrode sheets (8) and a potential collection instrument (10). The potential collection instrument (10) is arranged outside the sealed chamber (5). The two electrode sheets (8) are in contact with two ends of the coal sample (7). The two electrode sheets (8) are connected to the potential collection instrument (10) via a wire (12).

7. A device for testing the potential of gas-containing coal during impact loading as claimed in claim 6, characterized in that: A front-end amplifier (11) is provided between the two electrode sheets (8) and the potential collector (10) for amplifying the voltage signal.

8. The testing method of a gas-containing coal impact loading process potential testing device according to any one of claims 1 to 7, characterized in that: The following steps are involved: S100: The transmission rod (4) is fixedly connected to the side wall of the test chamber (2), the incident rod (3) passes through the side wall of the test chamber (2) and is slidably connected to the test chamber (2), and the incident rod (3) and the transmission rod (4) and the coal sample (7) are clamped inside the test chamber (2); S200: the test chamber (2) is evacuated to a vacuum state and then left to stand for at least 2 hours, and then gas is charged into the test chamber (2) to make the gas pressure in the test chamber (2) between 0.2 MPa and 1 MPa, and maintained for at least 12 hours, so that the coal sample (7) can fully absorb the gas; S300: Stop charging gas into the test chamber (2), then start continuously collecting and storing voltage signals at both ends of the coal sample (7), and the impact loading device provides an impact force to the incident rod (3) so that the incident rod (3) and the transmission rod (4) squeeze the coal sample (7) against each other.

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