CN206208842U - A kind of experimental rig and pilot system that coal containing methane gas Burst Tendency index and acoustic feature are measured for uniaxial compression - Google Patents

Abstract

The utility model is related to a kind of experimental rig and pilot system that coal containing methane gas Burst Tendency index and acoustic feature are measured for uniaxial compression, the experimental rig includes base, sealing drum, top pressure closure and seaming chuck, sealing drum is detachably connected with base and top pressure closure respectively, and seaming chuck coordinates with the scalloped channels gap of top pressure closure center；Base center is coaxially provided with push-down head with seaming chuck, and upper and lower pressure head corresponding position is respectively provided with the cell body for accommodating ultrasonic probe；The lead channels of inlet channel and exhaust passage and ultrasonic probe are respectively equipped with seaming chuck and base；Base both sides are additionally provided with the bnc interface and one-wire interface for being respectively used to be connected with acoustic emission sensor and stressometer, and the respective wire of bnc interface and one-wire interface is passed from base.The utility model can ensure that coal sample carries out uniaxial compression experiment under certain gas pressure, and obtain accurately relevant parameter data.

Description

A method for uniaxial compression measurement of impact tendency index and acoustic characteristics of gas-containing coal The test device and test system

technical field

The utility model belongs to the research technology of mechanical and acoustic characteristics of gas-containing coal in the process of coal mining, in particular to a test device and a test system for measuring the impact tendency index and acoustic characteristics of gas-containing coal by uniaxial compression.

Background technique

The instability of the coal-rock system is a prerequisite for the occurrence of coal-rock gas dynamic disasters, and the occurrence of instability and failure depends on whether the strength failure of the gas-containing coal body occurs and the corresponding mechanical response. Coal is a complex porous medium, a natural adsorbent, and a large amount of gas can be adsorbed in coal. Therefore, the study of coal-rock gas dynamic disasters should first study the influence of gas on the physical and mechanical properties of coal, which is the basis for studying the failure mechanism and constitutive relationship of gas-containing coal. Existing related studies are mainly carried out in the case of conventional triaxial. However, most of the physical and mechanical indicators of coal and rock in national standards are obtained under uniaxial action. Therefore, if the mechanical index of gas-containing coal body under uniaxial action can be measured to compare and analyze the mechanical index of coal body under the condition of no gas, it can further reveal the influence law of the existence of gas on the physical and mechanical properties of coal body, so as to further Further reveal the mechanism of disaster occurrence.

Utility model content

The purpose of this utility model is to provide a test device and test system for uniaxial compression measurement of gas-containing coal impact tendency index and acoustic characteristics, which can ensure that coal samples are subjected to uniaxial compression experiments under a certain gas pressure, and obtain accurate results. corresponding parameter data.

For solving the problems of the technologies described above, the technical scheme that the utility model adopts is as follows:

A test device for measuring impact tendency index and acoustic characteristics of gas-containing coal by uniaxial compression. The test device includes a base, a sealing cylinder, a sealing top cover and an upper pressure head. The sealing cylinder can be connected with the base and the sealing top cover respectively. Disassemble the connection, and the upper indenter fits with the gap channel at the center of the sealing top cover; the lower indenter is coaxial with the upper indenter in the center of the base, and the corresponding positions of the upper and lower indenters are respectively equipped with grooves for accommodating ultrasonic probes ;The upper indenter and the base are respectively provided with an air intake channel, an exhaust channel, and a wire channel for the ultrasonic probe; there are also BNC interfaces and single-line interfaces for connecting with the acoustic emission sensor and the strain gauge on both sides of the base, and the BNC interface Corresponding wires to the single-wire interface pass out from the base.

Preferably, sealing gaskets are respectively provided at the joints of the sealing cylinder, the sealing top cover and the base.

Preferably, the upper indenter is provided with a positioning boss at the bottom surface of the corresponding sealing top cover, and the bottom surface of the sealing top cover is provided with a positioning groove matching with the positioning boss.

Preferably, the sealing top cover is provided with a sealing gasket on the inner wall of the notch channel matched with the upper pressure head.

Preferably, the corresponding positions of the upper indenter and the lower indenter are all detachably provided with air-permeable plates for bonding ultrasonic probes, and the air-permeable plates are provided with air-ventilating holes corresponding to the air intake channels and exhaust channels, and the air-permeable plates correspond to the ultrasonic probes. The probe is provided with an annular ventilating groove.

Preferably, the outer wall of the lower pressure head is covered with a positioning cylinder for positioning the coal sample column, and the horizontal height of the top surface of the positioning cylinder is greater than the horizontal height of the top surface of the air-permeable plate of the lower pressure head.

Using the test system of the above-mentioned test device for measuring gas-containing coal impact tendency index and acoustic characteristics by uniaxial compression, the system also includes an acoustic characteristic measurement device, a stress-strain measurement device, an ultrasonic detection device and a gas filling device; The ultrasonic measurement device includes upper and lower ultrasonic probes located in the upper and lower pressure head grooves respectively. The upper and lower ultrasonic probes are bonded to the air-permeable plate and the wires are passed through the wire channel and connected to the external intelligent ultrasonic comprehensive tester;

The acoustic feature measuring device includes an acoustic emission sensor located inside the sealed cylinder, the acoustic emission sensor is connected to the BNC interface through a wire, and the BNC interface passes through the base through a wire and is connected to an external acoustic emission monitor;

The stress-strain measuring device includes a strain gauge located inside the sealed cylinder, the strain gauge is connected to the single-wire interface through a wire, and the single-wire interface passes through the base through a wire and is connected to an external stress-strain gauge;

The gas filling device includes a vacuuming mechanism and a gas charging mechanism. The vacuuming mechanism includes an air pump connected to the air inlet channel of the upper pressure head through a suction pipe. The gas charging mechanism includes an inflation pipe connected to the suction pipe through a three-way pipe. The pipe is connected to the gas tank, the first valve is provided on the suction pipe between the three-way pipe and the suction pump, and the air pressure gauge and the second valve are provided on the inflation pipe;

The exhaust passage of the base communicates with the outside through an exhaust pipe, and a third valve is arranged on the exhaust pipe.

When using the above-mentioned test system for uniaxial compression measurement of the impact tendency index and acoustic characteristics of gas-containing coal, it is first necessary to assemble the system, place the upper and lower ultrasonic probes in the corresponding grooves and bond them to the gas-permeable plate, and then connect the Fix the air-permeable plate on the upper and lower pressure heads, and then insert the coal sample column in the middle of the positioning sleeve of the lower pressure head, and then bond the strain gauge and the acoustic emission sensor to the surface of the coal sample column through the coupling agent, and then make the upper The air-permeable plate at the indenter and the lower indenter presses the coal sample column tightly, and finally the sealing cylinder, sealing top cover, upper indenter and base are assembled through the connecting parts; after the system is assembled, the inside of the sealing ring is vacuumed Vacuumize, and then fill the inside of the sealing ring with gas through the gas inflation mechanism until the barometer index does not change, then close the corresponding valve, load and unload the pressure on the upper pressure head through the servo pressure head of the rock mechanics testing machine, and record the intelligent ultrasonic pressure. The data changes of the pressure and stress strain gauges of the comprehensive testing instrument and the acoustic emission monitor are sorted out to obtain the stress-strain full course curve, acoustic emission characteristic parameter diagram and longitudinal wave and transverse wave waveform diagram of the gas-containing coal uniaxial compression test;

3) Pressure relief and disassembly. After the test is completed, discharge the gas in the sealing cylinder through the exhaust pipe, and then follow the reverse operation of step 1) to disassemble and assemble each mechanism.

Compared with the prior art, the utility model has the following advantages:

1) The utility model adopts uniaxial compression to measure the impact tendency and acoustic characteristic parameters of gas-containing coal, which makes up for some disadvantages of the impact tendency index test method in the prior art, and the measured data is closer to the actual engineering situation of the coal mine. Provide reference for prediction and prevention of rock burst disasters;

2) The acoustic emission sensor is placed inside and directly pasted on the surface of the coal sample column, which avoids the problems of signal failure and many interference factors caused by the external placement of the acoustic emission sensor in the prior art, and the accuracy of the acoustic emission signal can be improved. Greatly improved, thereby improving the reliability of acoustic emission monitoring;

3) Multiple sealing rings are used to seal and seal the joints of each mechanism to ensure the tightness inside the sealing rings and improve the accuracy of corresponding parameters;

4) The structure is small and simple and has various functions. It can monitor stress and strain, acoustic emission signal and acoustic wave signal at the same time. After the utility model is connected with the external device components used for the triaxial compression test of gas-containing coal, the gas-containing coal can be tested. Triaxial compression test.

Description of drawings

Fig. 1 is a schematic structural view of a test device for uniaxial compression measurement of gas-containing coal impact tendency index and acoustic characteristics in a specific embodiment;

Fig. 2 is the structural representation of sealing top cover in the test device shown in Fig. 1;

Fig. 3 is the structural representation of the air-permeable plate in the test device shown in Fig. 1;

Fig. 4 is a schematic structural diagram of a test system used for uniaxial compression to measure impact tendency index and acoustic characteristics of gas-containing coal.

detailed description

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model.

As shown in Figures 1-4, a test device for measuring the impact tendency index and acoustic characteristics of gas-containing coal by uniaxial compression, the test device includes a base 10, a sealing cylinder 20, a sealing top cover 30 and an upper pressure head 40, the sealing cylinder 20 is detachably connected with the base 10 and the sealing top cover 30 respectively, the joints of the sealing cylinder 20 and the sealing top cover and the base are respectively provided with sealing gaskets 21, and the upper pressure head 40 and the gap at the center of the sealing top cover 30 The channel 31 is clearance fit, the inner wall of the notch channel 31 is provided with a sealing gasket 32, the upper pressure head 40 is provided with a positioning boss 45 at the bottom surface of the corresponding sealing top cover 30, and the bottom surface of the sealing top cover 30 is provided with a positioning boss 45 to cooperate with. Groove 33; the center of the base is provided with a lower indenter coaxially with the upper indenter, and the upper indenter and the base are respectively provided with an air inlet passage 41 and an exhaust passage 15, as well as a wire passage 42 of the upper ultrasonic probe and a lower ultrasonic probe. Conductor channel 16; the corresponding positions of the upper and lower indenters are respectively provided with a tank body 44 and a tank body 13 for accommodating the ultrasonic probe, and the corresponding positions of the upper indenter and the lower indenter are provided with a breathable plate 43 for bonding the ultrasonic probe through bolts, Ventilation plate 43 is provided with vent hole 18 corresponding to air intake passage 41 and exhaust passage 15 places, and ventilating plate 43 is provided with annular ventilating groove 17 at the corresponding ultrasonic probe place, and ventilating plate 43 is provided with installation hole 19 at the corresponding bolt place, and described lower The outer wall of the indenter is provided with a positioning cylinder 14 for positioning the coal sample column. The top surface level of the positioning cylinder 14 is greater than the top surface level of the air-permeable plate of the lower pressure head; The BNC interface 11 and the single-line interface 12 connected to the strain gauge, and the corresponding wires of the BNC interface 11 and the single-line interface 12 pass through the base.

Using the test system of the above-mentioned test device for measuring gas-containing coal impact tendency index and acoustic characteristics by uniaxial compression, the system also includes an acoustic characteristic measurement device, a stress-strain measurement device, an ultrasonic detection device and a gas filling device; The ultrasonic measurement device includes an upper ultrasonic probe 80 located in the upper indenter groove, and a lower ultrasonic probe 81 in the lower indenter groove. The upper and lower ultrasonic probes are bonded to the air-permeable plate 43 and the wires are passed through the corresponding wire channels. And be connected with the intelligent ultrasonic comprehensive tester 82 of the outside;

The acoustic feature measurement device includes an acoustic emission sensor 60 located inside the sealed cylinder 20, the acoustic emission sensor is connected to the BNC interface 11 through the wire 60, and the BNC interface 11 passes through the base through the wire and is connected to the external acoustic emission monitor 61;

The stress-strain measuring device includes a strain gauge 70 located inside the sealed cylinder, the strain gauge 70 is connected to the single-line interface 12 through a wire, and the single-line interface 12 passes through the base through a wire and is connected to an external stress-strain gauge 71;

The gas filling device includes a vacuum pumping mechanism and a gas charging mechanism. The vacuum pumping mechanism includes an air suction pump 90 connected to the upper pressure head inlet channel 41 through a suction pipe. tube, the inflation tube is connected with the gas tank 93, the exhaust tube between the three-way tube 92 and the air pump 90 is provided with a first valve 91, and the inflation tube is provided with a barometer 95 and a second valve 94;

The exhaust channel 15 of the base communicates with the outside world through an exhaust pipe, and a third valve 96 is arranged on the exhaust pipe.

When using the above-mentioned test system for uniaxial compression measurement of the impact tendency index and acoustic characteristics of gas-containing coal, it is first necessary to assemble the system, place the upper and lower ultrasonic probes in the corresponding grooves and bond them to the gas-permeable plate, and then connect the Fix the air-permeable plate on the upper and lower pressure heads, and then insert the coal sample column in the middle of the positioning sleeve of the lower pressure head, and then bond the strain gauge and the acoustic emission sensor to the surface of the coal sample column through the coupling agent, and then make the upper The air-permeable plate at the indenter and the lower indenter presses the coal sample column tightly, and finally the sealing cylinder, sealing top cover, upper indenter and base are assembled through the connecting parts; after the system is assembled, the inside of the sealing ring is vacuumed Vacuumize, and then fill the inside of the sealing ring with gas through the gas inflation mechanism until the barometer index does not change, then close the corresponding valve, load and unload the pressure on the upper pressure head through the servo pressure head of the rock mechanics testing machine, and record the intelligent ultrasonic pressure. The data changes of the pressure and stress strain gauges of the comprehensive testing instrument and the acoustic emission monitor are sorted out to obtain the stress-strain full course curve, acoustic emission characteristic parameter diagram and longitudinal wave and transverse wave waveform diagram of the gas-containing coal uniaxial compression test;

3) Pressure relief and disassembly. After the test is completed, discharge the gas in the sealing cylinder through the exhaust pipe, and then follow the reverse operation of step 1) to disassemble and assemble each mechanism.

Claims (7)

1. a kind of experimental rig that coal containing methane gas Burst Tendency index and acoustic feature are measured for uniaxial compression, its feature exists In the experimental rig includes base, sealing drum, top pressure closure and seaming chuck, and sealing drum respectively can with base and top pressure closure Dismounting connection, seaming chuck coordinates with the scalloped channels gap of top pressure closure center；Base center is coaxially provided with seaming chuck Push-down head, upper and lower pressure head corresponding position is respectively provided with the cell body for accommodating ultrasonic probe；Be respectively equipped with seaming chuck and base into The lead channels of gas passage and exhaust passage and ultrasonic probe；Base both sides be additionally provided be respectively used to acoustic emission sensor and The respective wire of the bnc interface and one-wire interface of stressometer connection, bnc interface and one-wire interface is passed from base.

2. it is as claimed in claim 1 to be used for the experiment that uniaxial compression measures coal containing methane gas Burst Tendency index and acoustic feature Device, it is characterised in that the sealing drum is respectively equipped with seal washer with the joint of top pressure closure and base.

3. it is as claimed in claim 1 to be used for the experiment that uniaxial compression measures coal containing methane gas Burst Tendency index and acoustic feature Device, it is characterised in that seaming chuck is provided with positioning boss at correspondence top pressure closure bottom surface, and top pressure closure bottom surface is provided with and positioning The detent that boss coordinates.

4. it is as claimed in claim 1 to be used for the experiment that uniaxial compression measures coal containing methane gas Burst Tendency index and acoustic feature Device, it is characterised in that the scalloped channels inwall that top pressure closure coordinates with seaming chuck is provided with seal washer.

5. it is as claimed in claim 1 to be used for the experiment that uniaxial compression measures coal containing methane gas Burst Tendency index and acoustic feature Device, it is characterised in that the seaming chuck and push-down head corresponding position are all detachable to be provided with for being bonded the ventilative of ultrasonic probe Plate, air-vent is provided with air permeable plate at correspondence inlet channel and exhaust passage, is provided with annular saturating at air permeable plate correspondence ultrasonic probe Air drain.

6. it is as claimed in claim 5 to be used for the experiment that uniaxial compression measures coal containing methane gas Burst Tendency index and acoustic feature Device, it is characterised in that the push-down head outer wall is arranged with the positioning tube for positioning coal sample post, the top surface level of positioning tube is high Ventilative plate top surface level height of the degree more than push-down head.

7. using the examination for measuring coal containing methane gas Burst Tendency index and acoustic feature described in claim 1-6 for uniaxial compression The pilot system of experiment device, it is characterised in that the system also include acoustic feature measurement apparatus, stress-strain measurement device, Ultrasonic sensor and gas filling device；The ultrasonic sensor includes upper and lower in upper and lower head tank body respectively Ultrasonic probe, upper and lower ultrasonic probe is bonded on air permeable plate and passes wire by lead channels and surpass with extraneous intelligence Sound comprehensive tester is connected；

The acoustic feature measurement apparatus include the acoustic emission sensor inside sealing drum, and acoustic emission sensor passes through wire It is connected with bnc interface, bnc interface passes base and is connected with extraneous acoustic emission automonitor by wire；

The stress-strain measurement device includes the stressometer inside sealing drum, and stressometer is connected by wire with one-wire interface Connect, one-wire interface passes base and is connected with extraneous stress-strain gage by wire；

The gas filling device include vacuum device and gas inflation mechanism, vacuum device include by exhaust tube with it is upper The aspiration pump of pressure head inlet channel connection, gas inflation mechanism includes the gas tube being connected with exhaust tube by three-way pipe, inflation Pipe is connected with gas pot, and the exhaust tube between three-way pipe and aspiration pump is provided with the first valve, gas tube be provided with air gauge with Second valve；

The exhaust passage of the base is in communication with the outside by blast pipe, and blast pipe is provided with the 3rd valve.