Stress-gas-temperature multi-field coupled dynamic load disturbance test system

Abstract

The invention discloses a stress-gas-temperature multi-field coupled dynamic load disturbance test system, and belongs to the field of safety science and engineering.The stress-gas-temperature multi-field coupled dynamic load disturbance test system comprises an experiment table, a test cavity is formed in the upper surface of the experiment table, and a true triaxial confining pressure partition loading system and a stratum partition heating system are arranged in the test cavity; a first gas pipeline is arranged at the bottom corner of the right side wall of the test cavity in a penetrating mode, the interior of the test cavity is connected with an adsorption gas pressurization system through the first gas pipeline, a collision pressing plate is arranged on the inner wall of the left side of the test cavity in a penetrating mode, and an external dynamic load disturbance system is arranged on the left side of the collision pressing plate. The stress-gas-temperature multi-field coupled dynamic load disturbance test system is used for studying the influence of dynamic load, confining pressure, air pressure and terrestrial heat on the mechanical properties of the sample and the influence of damage, fracture development and gas adsorption and desorption, and guidance is provided for coal mine safety production.

Description

Technical Field

[0001] The invention relates to the field of safety science and engineering, and in particular to a stress-gas-temperature multi-field coupled dynamic load disturbance test system. Background Art

[0002] At present, my country's shallow coal resources have been basically mined, and the mining of middle and a few deep coal resources is the main focus, and the overall mining is being carried out at a speed of 10-20m / a. With the increase in my country's annual demand for coal, deep coal resources will inevitably become the main mining. With the increase in the depth of coal seam mining, the coal seam environment has gradually become more complex, mainly manifested in increased ground stress, increased gas pressure, increased gas content, reduced coal seam permeability, and increased ground temperature. It is more likely to trigger accidents such as rock burst, coal and gas outbursts, resulting in increased severity of coal mine accidents. The mining process will face severe challenges.

[0003] Accidents in coal mines are caused by the coupling of multiple factors, and the mechanisms of accidents are complex and diverse, such as coal and gas outburst. Therefore, in order to explore the mechanism and mechanism of coal and gas outburst accidents, it is necessary to simulate and study the mechanical properties, damage, fracture development, gas adsorption and desorption of raw coal rock samples in real geological environments, which can effectively prevent the risk of accidents, reduce the number of accidents, and reduce the intensity of accidents, and provide favorable guidance for solving the safe mining of deep coal and safe excavation of underground engineering. Through the investigation of literature, it is found that most of the existing test systems include true triaxial test equipment and carry out related research. The true triaxial test equipment is designed so that each true triaxial loading plate is a loading area, and the pressure in the loading area is considered to be equal everywhere, which can realize true triaxial surface stress loading in different directions. Due to some functional defects in the existing test system, the plate stress partition loading cannot be realized, the geothermal factor is not considered, and the external dynamic load disturbance function is lacking. It cannot highly restore the real geological environment of coal and rock strata, and cannot fully reveal the mechanism and mechanism of coal and gas outburst accidents.

[0004] In view of the problems such as the inadequate functions of the existing test system, it is necessary to study a dynamic load disturbance test system with stress-gas-temperature multi-field coupling. This test system adds an external dynamic load disturbance device and a formation heating device on the basis of the existing test system, and at the same time improves the true triaxial confining pressure loading device, which not only meets the external impact dynamic load disturbance function, but also adds formation geothermal and zone heating functions, and realizes the true triaxial confining pressure zone loading function. This test system can realize the changes in the mechanical properties of coal and rock samples under different intensities of external dynamic load disturbances, the changes in the mechanical properties of coal and rock samples under true triaxial confining pressure zone loading, and the changes in the mechanical properties of coal and rock samples under formation zone heating. Studying a dynamic load disturbance test system with stress-gas-temperature multi-field coupling is not only conducive to preventing coal and gas outburst accidents, but also conducive to guiding coal mine safety production. Summary of the invention

[0005] The purpose of the present invention is to provide a stress-gas-temperature multi-field coupled dynamic load disturbance test system, which can not only be used to study the changes in the mechanical properties of samples caused by dynamic load disturbances of different intensities, the changes in the mechanical properties of samples caused by different confining pressure zone loading, the changes in the mechanical properties of samples caused by different air pressure environments, the changes in the mechanical properties of samples caused by different geothermal environments, etc., but can also further study the influence of the changes in the mechanical properties of samples on their damage, crack development, and gas adsorption and desorption, providing favorable guidance for safe production in coal mines.

[0006] To achieve the above-mentioned objectives, the present invention provides a stress-gas-temperature multi-field coupled dynamic load disturbance test system, comprising a test bench, a test cavity is provided on the upper surface of the test bench, a true triaxial confining pressure zone loading system and a formation zone heating system are provided inside the test cavity, a first gas pipeline is penetrated through the bottom corner of the right side wall of the test cavity, an adsorption gas pressurization system is connected to the inside of the test cavity through the first gas pipeline, a collision pressure plate is penetrated through the left inner wall of the test cavity, and an external dynamic load disturbance system is provided on the left side of the collision pressure plate.

[0007] Preferably, one side of the test cavity is connected to an anti-collision bracket via a fixing bolt, and the anti-collision bracket is fixed to the upper surface of the experimental table.

[0008] Preferably, the true three-axis confining pressure zoned loading system includes a plurality of hydraulic oil pumps, pressure plates, and air pressure sensors. The plurality of hydraulic oil pumps are arranged through the outer surface of the test cavity. The pressure plate is arranged on the inner wall surface of the test cavity and connected to the output ends of the plurality of hydraulic oil pumps. The air pressure sensor is arranged at the top corner of the test cavity.

[0009] Preferably, the pressure plate is composed of several small pressure plates, each of which is connected to the output end of the hydraulic oil pump. The formation zone heating system includes the small pressure plate, a heating wire, a thermocouple, and a temperature control box. A groove is provided on the surface of the small pressure plate away from the hydraulic oil pump. The heating wire and the thermocouple are arranged inside the groove on the surface of the small pressure plate. The heating wire and the thermocouple are respectively connected to the temperature control box by wires.

[0010] Preferably, the adsorption gas pressurization system includes an adsorption gas cylinder, a first pressure regulating valve, a first pressure gauge, and a first switch. The adsorption gas cylinder is connected to the first gas pipeline through the first pressure regulating valve, the first pressure gauge, and the first switch in sequence. The gas pressure entering the test chamber is adjusted by controlling the first pressure regulating valve and the first switch.

[0011] Preferably, the external dynamic load disturbance system includes a nitrogen cylinder, a second gas pipeline, a gas storage cylinder, a slider, a light speed sensor, an acceleration pipeline, a data acquisition instrument, and a bracket. The nitrogen cylinder is connected to the gas storage cylinder through the second gas pipeline. The second gas pipeline is connected to a second pressure regulating valve, a second pressure gauge, and a second switch. The internal air pressure of the gas storage cylinder is adjusted by controlling the second pressure regulating valve and the second switch. The second pressure indication number is the internal air pressure value of the gas storage cylinder.

[0012] Preferably, the gas cylinder is connected to one end of the acceleration pipe through a third gas pipe, a solenoid valve is provided at the connection between the third gas pipe and the gas cylinder, the other end of the acceleration pipe corresponds to the outer end surface of the collision pressure plate, the slider is arranged inside the acceleration pipe, the gas cylinder and the acceleration pipe are both fixed on the upper surface of the experimental table through the bracket, and the light speed sensor is arranged on the inner wall of the acceleration pipe near one end of the collision pressure plate.

[0013] Therefore, the present invention adopts the above-mentioned stress-gas-temperature multi-field coupled dynamic load disturbance test system, which has the following technical effects:

[0014] (1) The present invention includes an external dynamic load disturbance system, which can realize dynamic load disturbances of different intensities, simulate and study the changes in the mechanical properties of coal and rock samples caused by dynamic load disturbances of different intensities, provide a strong basis for the study of damage and destruction of coal and rock samples, and have important significance for the study of the destruction morphology of coal and rock formations;

[0015] (2) The present invention includes a true triaxial confining pressure zone loading system, which can realize confining pressure zone loading of coal rock samples, simulate and study the changes in mechanical properties of coal rock samples under different confining pressure zone loading, provide parameter support for the study of crack development in coal rock samples, and is of great significance for the study of improving coal seam permeability;

[0016] (3) The present invention includes an adsorbed gas pressurization system, which can realize the gas pressure environment of coal rock samples, simulate and study the changes in the mechanical properties of coal rock samples under different gas pressure environments, play a guiding role in the prevention and control of accidents such as coal and gas outbursts, and is of great significance to ensuring safe production in coal mines;

[0017] (4) The present invention includes a formation zone heating system, which can realize zone heating of coal rock samples, simulate and study the changes in the mechanical properties of coal rock samples under different geothermal environments, provide a strong basis for the study of damage and fracture development of coal rock samples, and is of great significance to coal mine safety production and accident prevention.

[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of a stress-gas-temperature multi-field coupled dynamic load disturbance test system of the present invention;

[0020] Figure 2 It is a schematic diagram of the pressure plate structure of a stress-gas-temperature multi-field coupled dynamic load disturbance test system of the present invention;

[0021] Figure 3 The present invention is a schematic diagram of heating a small pressing plate in a stress-gas-temperature multi-field coupled dynamic load disturbance test system.

[0022] Reference numerals

[0023] 1. Experimental table; 2. Test chamber; 3. True triaxial confining pressure zone loading system; 31. Hydraulic oil pump; 32. Press plate; 321. Small press plate; 33. Air pressure sensor; 4. Formation zone heating system; 41. Heating wire; 42. Thermocouple; 43. Temperature control box; 5. First gas pipeline; 6. Adsorption gas pressurization system; 61. Adsorption gas cylinder; 62. First pressure regulating valve; 63. First pressure gauge; 64. First switch; 7. Collision plate; 8. External dynamic load disturbance system; 81. Nitrogen cylinder; 82. Second gas pipeline; 83. Gas storage cylinder; 84. Sliding block; 85. Light speed sensor; 86. Acceleration pipeline; 87. Bracket; 9. Anti-collision bracket; 10. Solenoid valve; 11. Third gas pipeline; 12. Second pressure regulating valve; 13. Second pressure gauge; 14. Second switch; 15. Data acquisition instrument. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0025] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0026] Embodiment 1

[0027] like Figure 1 to Figure 2 As shown, a stress-gas-temperature multi-field coupled dynamic load disturbance test system includes a test bench 1, a test cavity 2 is provided on the upper surface of the test bench 1, one side of the test cavity 2 is connected to an anti-collision bracket 9 by a fixing bolt, and the anti-collision bracket 9 is fixed to the upper surface of the test bench 1 to ensure the stability and safety of the test cavity 2. The test cavity 2 is made of an alloy material with a high stiffness coefficient and is connected with high-strength bolts to prevent deformation and damage of the test cavity 2 structure during the test. A true triaxial confining pressure partition loading system 3 and a formation partition heating system 4 are provided inside the test cavity 2.

[0028] The true triaxial confining pressure zoned loading system 3 includes a plurality of hydraulic oil pumps 31, a pressure plate 32, and an air pressure sensor 33. The hydraulic oil pump 31 is arranged on the outer surface of the test cavity 2, and the pressure plate 32 is arranged on the inner wall surface of the test cavity 2 and connected to the output ends of the hydraulic oil pump 31, so as to perform confining pressure loading on the test piece inside the test cavity 2. The air pressure sensor 33 is arranged at the top corner of the test cavity 2, so as to monitor the air pressure changes inside the test cavity 2. Among them, the pressure plate 32 is composed of a plurality of small pressure plates 321, and each small pressure plate 321 is connected to the output end of the hydraulic oil pump 31, so that the loading pressure of different areas can be controlled more accurately, and both graded confining pressure loading and synchronous confining pressure loading can be realized.

[0029] like Figure 3 As shown, the formation zone heating system 4 includes a small pressing plate 321, a heating wire 41, a thermocouple 42, and a temperature control box 43. A groove is provided on the surface of the small pressing plate 321 away from the hydraulic oil pump 31. The heating wire 41 and the thermocouple 42 are arranged inside the groove on the surface of the small pressing plate 321 to perform local heating and temperature monitoring on the specimen. The heating wire 41 and the thermocouple 42 are respectively connected to the temperature control box 43 by wires to achieve precise temperature control.

[0030] A first gas pipeline 5 is provided through the bottom corner of the side wall of the test chamber 2 near the anti-collision bracket 9, and the inside of the test chamber 2 is connected to an adsorption gas pressurizing system 6 through the first gas pipeline 5. The adsorption gas pressurizing system 6 includes an adsorption gas cylinder 61, a first pressure regulating valve 62, a first pressure gauge 63, and a first switch 64. The adsorption gas cylinder 61 is connected to the first gas pipeline 5 through the first pressure regulating valve 62, the first pressure gauge 63, and the first switch 64 in sequence, and the gas pressure entering the test chamber 2 is adjusted by controlling the first pressure regulating valve 62 and the first switch 64.

[0031] A collision plate 7 is provided through the inner wall on the left side of the test chamber 2, and an external dynamic load disturbance system 8 is provided on the left side of the collision plate 7. The external dynamic load disturbance system 8 includes a nitrogen bottle 81, a second gas pipeline 82, a gas cylinder 83, a slider 84, a light speed sensor 85, an acceleration pipeline 86, a bracket 87, and a data acquisition instrument 15. The nitrogen bottle 81 is connected to the gas cylinder 83 through the second gas pipeline 82, and the second gas pipeline 82 is connected to the second pressure regulating valve 12, the second pressure gauge 13, and the second switch 14. The internal air pressure of the gas cylinder 83 is adjusted by controlling the second pressure regulating valve 12 and the second switch 14, and the reading of the second pressure gauge 13 is the internal air pressure value of the gas cylinder 83. The gas cylinder 83 is connected to one end of the acceleration pipeline 86 through the third gas pipeline 11, and a solenoid valve 10 is provided at the connection between the third gas pipeline 11 and the gas cylinder 83. The solenoid valve 10 is manually controlled to control the release of gas in the gas cylinder 83, and there is no gas leakage at the outlet. The other end of the acceleration pipe 86 corresponds to the outer end surface of the collision plate 7. The slider 84 is arranged inside the acceleration pipe 86. The acceleration pipe 86 is a rigid and smooth pipe. The slider 84 moves approximately frictionlessly along the inner wall of the pipe under the action of nitrogen. The slider 84 hits the outer end of the collision plate 7, thereby applying dynamic load disturbance to the test piece inside the test cavity 2. The gas storage bottle 83 and the acceleration pipe 86 are both fixed on the upper surface of the experimental table 1 through the bracket 87. The light speed sensor 85 is arranged on the inner wall of the acceleration pipe 86 near one end of the collision plate 7, and is connected to the data acquisition instrument 15 to monitor the moving speed of the slider 84. The air pressure sensor 33 in the true three-axis confining pressure partition loading system 3 is also electrically connected to the data acquisition instrument 15 to monitor the air pressure changes inside the test cavity 2.

[0032] Working principle: 1. Activate the true triaxial confining pressure zone loading system 3, place the specimen into the test chamber 2, control the computer and set the same and smaller loading value of the hydraulic oil pump 31, and pressurize and fix the specimen with the pressing plate 32;

[0033] 2. Activate the adsorbed gas pressurizing system 6: After the pressure plate 32 is pressurized to fix the sample, adjust the first pressure regulating valve 62, and after the reading of the first pressure gauge 63 reaches a preset value and stabilizes, open the first switch 64 to force the adsorbed gas to enter the cavity, and close the first switch 64 in time;

[0034] 3. Activate the formation zone heating system 4: After the adsorption gas is pressurized, turn on the temperature control box 43, and adjust the heat generation of the heating wire 41 by the knob to control the formation zone heating temperature;

[0035] 4. Activate the true triaxial confining pressure zone loading system 3: After the heating temperature of the pressing plate 32 reaches the preset value and stabilizes, the small pressing plate 321 is adjusted by the hydraulic oil pump 31 to realize the zone pressurization and heating of the sample;

[0036] 5. Activate the external dynamic load disturbance system 8: After the sample is pressurized and heated in different zones, adjust the second pressure regulating valve 12, and after the reading of the second pressure gauge 13 reaches a preset value and stabilizes, open the second switch 14 to force nitrogen to enter the gas storage bottle 83, and close the second switch 14 in time, and then open the solenoid valve 10 to release the nitrogen in the gas storage bottle 83;

[0037] 6. Enable the data acquisition system: connect the data acquisition instrument 15 to the sensor, output, display and record the relevant monitoring data.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A stress-gas-temperature multi-field coupled dynamic load disturbance test system, characterized in that: The experimental platform comprises a test chamber, the upper surface of which is provided with a test chamber, the inside of which is provided with a true triaxial confining pressure zoned loading system and a formation zoned heating system, a first gas pipeline is penetrated through the bottom corner of the right wall of the test chamber, the inside of the test chamber is connected with an adsorption gas pressurization system through the first gas pipeline, a collision pressure plate is penetrated through the left inner wall of the test chamber, and an external dynamic load disturbance system is provided on the left side of the collision pressure plate.

2. The stress-gas-temperature multi-field coupled dynamic load disturbance test system according to claim 1, characterized in that: One side of the test cavity is connected to an anti-collision bracket via a fixing bolt, and the anti-collision bracket is fixedly arranged on the upper surface of the experimental table.

3. The stress-gas-temperature multi-field coupled dynamic load disturbance test system according to claim 1, characterized in that: The true three-axis confining pressure zoned loading system includes a plurality of hydraulic oil pumps, pressure plates, and air pressure sensors. The plurality of hydraulic oil pumps are arranged through the outer surface of the test cavity. The pressure plates are arranged on the inner wall surface of the test cavity and connected to the output ends of the plurality of hydraulic oil pumps. The air pressure sensors are arranged at the top corners of the test cavity.

4. The stress-gas-temperature multi-field coupled dynamic load disturbance test system according to claim 3, characterized in that: The pressure plate is composed of several small pressure plates, each of which is connected to the output end of the hydraulic oil pump. The formation zone heating system includes the small pressure plate, a heating wire, a thermocouple, and a temperature control box. A groove is provided on the surface of the small pressure plate away from the hydraulic oil pump. The heating wire and the thermocouple are arranged inside the groove on the surface of the small pressure plate. The heating wire and the thermocouple are respectively connected to the temperature control box by wires.

5. The stress-gas-temperature multi-field coupled dynamic load disturbance test system according to claim 1, characterized in that: The adsorption gas pressurization system includes an adsorption gas cylinder, a first pressure regulating valve, a first pressure gauge, and a first switch. The adsorption gas cylinder is connected to the first gas pipeline through the first pressure regulating valve, the first pressure gauge, and the first switch in sequence. The gas pressure entering the test chamber is adjusted by controlling the first pressure regulating valve and the first switch.

6. The stress-gas-temperature multi-field coupled dynamic load disturbance test system according to claim 1, characterized in that: The external dynamic load disturbance system includes a nitrogen cylinder, a second gas pipeline, a gas storage cylinder, a slider, a light speed sensor, an acceleration pipeline, and a bracket. The nitrogen cylinder is connected to the gas storage cylinder through the second gas pipeline. The second gas pipeline is connected to a second pressure regulating valve, a second pressure gauge, and a second switch. The internal air pressure of the gas storage cylinder is adjusted by controlling the second pressure regulating valve and the second switch. The second pressure indication number is the internal air pressure value of the gas storage cylinder.

7. The stress-gas-temperature multi-field coupled dynamic load disturbance test system according to claim 6, characterized in that: The gas cylinder is connected to one end of the acceleration pipe through a third gas pipe, and a solenoid valve is provided at the connection between the third gas pipe and the gas cylinder. The other end of the acceleration pipe corresponds to the outer end surface of the collision pressure plate. The slider is arranged inside the acceleration pipe. The gas cylinder and the acceleration pipe are both fixed on the upper surface of the experimental table through the bracket, and the light speed sensor is arranged on the inner wall of the acceleration pipe near one end of the collision pressure plate.

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