Device for testing gas-liquid two-phase seepage mechanical coupling characteristic of broken coal and rock mass

Abstract

The utility model relates to the field of broken coal and rock mass seepage testing, in particular to a device for testing gas-liquid two-phase seepage mechanical coupling characteristics of a broken coal and rock mass. Comprising an autoclave system, a gas-liquid two-phase flow injection system, a metering system, a confining pressure loading system and an axial pressure loading system, the high-pressure kettle system is arranged on the axial pressure loading system, the upper part of the high-pressure kettle system is connected with a loading column body, and a crushed coal and rock mass sample is integrally fixed in a closed kettle body; the gas-liquid two-phase flow injection system is connected with a gas-liquid inlet of the autoclave system; the metering system is connected with a gas-liquid outlet of the autoclave system, the metering system comprises a large-flow testing part and a small-flow testing part, and the measuring range can be expanded; and the confining pressure loading system is connected with the confining pressure cavity of the autoclave system. According to the invention, gas and liquid permeability test can be carried out on broken coal rock mass, the test device can be coupled with a hydraulic loading device, gas-liquid two-phase seepage mechanical coupling characteristic test is carried out, and the test and equipment application range is widened.

Description

TECHNICAL FIELD

[0001] The patent relates to the field of broken coal rock mass seepage testing, in particular to a broken coal rock mass gas-liquid two-phase seepage mechanics coupling characteristic testing device. BACKGROUND

[0002] In the process of coal mining, broken coal rock mass is often found in the following two situations: one is the caving broken coal rock accumulation body caused by mining disturbance and mine pressure in the goaf; the other is the engineering in-situ broken rock mass formed under the action of natural geological structure (such as fault, collapse column, etc.). Compared with complete and dense rock mass, the broken coal rock mass accumulation has a large number of pores and fissures, which provides a channel for the flow of mine fluid. However, since the broken body is the main accumulation form in the goaf caving zone or tectonic fracture zone, its existence state, pressure condition, particle size gradation, accumulation form (thickness, time, etc.) are unknown factors, which brings more uncertainty to the calculation of fluid seepage. Therefore, it is very important to study the seepage characteristics of broken coal rock mass for the safe mining of coal mines.

[0003] However, in the prior art, most of the broken coal rock mass seepage testing devices can only perform single gas permeability test or liquid permeability test, and it is difficult to perform extension test with other equipment, such as permeability test under pressure environment. In addition, in the existing test device, it is difficult to provide a high confining pressure environment under the premise of controlling the cost. CONTENT OF THE INVENTION

[0004] The patent proposes a broken coal rock mass gas-liquid two-phase seepage mechanics coupling characteristic testing device, which aims to design a test device that can test the gas and liquid permeability of broken coal rock mass, improve the test range, and couple the test device with a hydraulic loading device to test the gas-liquid two-phase seepage mechanics coupling characteristics. The sample sample can be fixed in a sealed kettle body, which is convenient for disassembly. In addition, a confining pressure pump that can provide high confining pressure is designed under the premise of controlling the cost.

[0005] In order to achieve the above purpose, the patent adopts the following technical solutions:

[0006] The broken coal rock mass gas-liquid two-phase seepage mechanics coupling characteristic testing device comprises a high-pressure kettle system, a gas-liquid two-phase flow injection system, a metering system, a confining pressure loading system and an axial pressure loading system.

[0007] The autoclave system comprises a rubber tube and an outer cylinder arranged coaxially, an annular space is formed between the rubber tube and the outer cylinder, an upper plug is arranged at the upper part of the rubber tube and the outer cylinder, a lower plug is arranged at the lower part of the rubber tube and the outer cylinder, the annular space between the rubber tube and the outer cylinder is closed to form a confining pressure cavity, and a confining pressure interface leading to the confining pressure cavity is arranged on the outer cylinder; the inner diameters of the rubber tube, the upper plug and the lower plug are the same, an upper plunger is arranged on the inner wall of the rubber tube and the upper plug, a lower plunger is arranged on the inner wall of the rubber tube and the lower plug, a gas-liquid outlet is arranged on the upper plunger, the gas-liquid outlet is connected to the inner cavity of the rubber tube through a pipeline arranged in the upper plunger, a gas-liquid inlet is arranged on the lower plunger, and the gas-liquid inlet is connected to the inner cavity of the rubber tube through a pipeline arranged in the lower plunger.

[0008] The gas-liquid two-phase flow injection system comprises a gas cylinder, the gas cylinder is connected with a valve F4, a pressure gauge P4 and a gas-liquid inlet in sequence through pipelines, and further comprises a liquid storage tank, one end of the liquid storage tank is connected with a valve F5, the gas cylinder, a pipeline between the valve F4 and the valve F6, a valve F3 and a first liquid source in sequence through pipelines, and the other end of the liquid storage tank is connected with a valve F6, a pipeline between the pressure gauge P4 and the gas-liquid inlet in sequence through pipelines.

[0009] The metering system comprises an electronic scale and a beaker system, a beaker of the electronic scale and the beaker system is connected with the gas-liquid outlet, a valve F10, a pressure gauge P2, a valve F12 in sequence through pipelines, a pipeline between the pressure gauge P2 and the valve F12, a valve F13 and a liquid flowmeter are further connected in sequence through pipelines, a pipeline between the valve F11, a drying cylinder, a valve F14 and a large-range gas flowmeter is further connected in sequence through pipelines, and a pipeline between the drying cylinder and the valve F14, a valve F15 and a small-range gas flowmeter are further connected in sequence through pipelines.

[0010] The confining pressure loading system comprises a confining pressure pump, a liquid outlet head of the confining pressure pump is connected with a valve F1, a pressure gauge P3 and a confining pressure interface in sequence through pipelines, and a liquid inlet head of the confining pressure pump is connected with a valve F2 and a second liquid source in sequence through pipelines.

[0011] The axial pressure loading system mainly comprises a loading column and a hydraulic loading machine for controlling the loading of the loading column.

[0012] Preferably, sealing rings are arranged between the upper plug, the lower plug and the outer cylinder.

[0013] Preferably, a liquid flowmeter, a liquid transfer pump, a valve F7 and a pipeline between the liquid storage tank and the valve F6 are connected in sequence through pipelines.

[0014] Preferably, the loading column is connected with a pressure gauge P1, a valve F8 and a hydraulic loading machine in sequence through pipelines, a pipeline between the valve F8 and the hydraulic loading machine, a valve and a hydraulic source are further connected in sequence through pipelines.

[0015] Preferably, the loading column body is fixedly connected with the upper end of the upper plunger through a clamp.

[0016] Preferably, the confining pressure pump comprises a pump head and a plunger which can slide in the pump head; a liquid outlet head is arranged at the end of the pump head away from the plunger; a liquid inlet head is arranged on the periphery of the pump head; a first fixing disc is fixed on the periphery of the plunger, and the bottom of the first fixing disc is fixed on a pump base; a second fixing disc is also fixed on the side of the pump base away from the first fixing disc; a guide cross rod is used to connect the first fixing disc and the second fixing disc; the guide cross rod is distributed along the periphery of the plunger and arranged in parallel with the plunger; the side of the plunger away from the pump head is arranged as a threaded sleeve structure; the threaded sleeve is threadedly connected with a threaded rod; the end of the threaded rod away from the threaded sleeve is arranged with a rotating handle and penetrates through the second fixing disc; and the threaded rod is rotationally connected with the second fixing disc; the threaded sleeve is arranged with a guide vertical rod corresponding to the guide cross rod on the periphery.

[0017] The beneficial technical effects of the patent are as follows: 1. The patent can test the gas and liquid permeability of broken coal rock mass, couple the test device with the hydraulic loading device, and test the gas-liquid two-phase seepage mechanics coupling characteristics, thereby improving the test range and equipment application range.

[0018] 2. The measurement system of the patent comprises a large-flow test part and a small-flow test part, thereby expanding the measurement range. The whole broken coal rock sample can be fixed in a sealed kettle body, and the kettle body is convenient to disassemble.

[0019] 3. The confining pressure pump designed in the patent is driven by liquid, is clean and easy to clean, can avoid large-area oil stains in the laboratory, and can provide high confining pressure under the premise of controlling the cost. BRIEF DESCRIPTION OF DRAWINGS

[0020] The drawings constituting the patent are used to provide a further understanding of the patent, and the schematic embodiments of the patent and the description thereof are used to explain the patent and do not constitute an improper limitation on the patent.

[0021] Figure 1 It is a whole structure schematic view of the gas-liquid two-phase seepage mechanics coupling characteristics test device of the patent.

[0022] Figure 2 It is a high-pressure kettle system structure schematic view of the gas-liquid two-phase seepage mechanics coupling characteristics test device of the patent.

[0023] Figure 3 It is a confining pressure pump structure schematic view of the gas-liquid two-phase seepage mechanics coupling characteristics test device of the patent.

[0024] Explanation of the accompanying symbols: 1. Gas cylinder; 2. Liquid storage tank; 3. Loading cylinder; 4. Sealing ring; 5. Confining pressure interface; 6. Lower plunger; 7. Gas-liquid inlet; 8. Clamp; 9. Gas-liquid outlet; 10. Upper plunger; 11. Upper plug; 12. Hose; 13. Cylinder; 14. Lower plug; 15. Electronic scale and beaker system; 16. Liquid flow meter; 17. Large-scale gas flow meter; 18. Small-scale gas flow meter; 19. Drying cylinder; 20. Confining pressure pump; 21. Liquid outlet head; 22. Pump head; 23. Plunger; 24. Sealing material; 25. Guide cross bar; 26. Threaded sleeve; 27. Pump seat; 28. Guide vertical rod; 29. ​​Threaded rod; 30. Rotating handle; 31. Liquid inlet head; 32a. First fixed plate; 32b. Second fixed plate; 33. Liquid transfer pump; 34. Confining pressure chamber; 35. Hydraulic loader. DETAILED DESCRIPTION

[0025] The specific embodiments of this patent are described in detail below with reference to the accompanying drawings.

[0026] Example 1

[0027] like Figures 1-2 The present invention provides a device for testing the mechanical coupling characteristics of gas-liquid two-phase seepage in crushed coal and rock masses, the device comprising a high-pressure autoclave system, a gas-liquid two-phase flow injection system, a metering system, a confining pressure loading system, and an axial pressure loading system.

[0028] The autoclave system includes a coaxially arranged hose 12 and an outer cylinder 13, an annulus is formed between the hose 12 and the outer cylinder 13, the length of the hose 12 is smaller than the outer cylinder 13, an upper plug 11 is provided on the upper part of the hose 12 and the outer cylinder 13, and a lower plug 14 is provided on the lower part of the hose 12 and the outer cylinder 13, so that the annulus between the hose 12 and the outer cylinder 13 is sealed to form a confined pressure chamber 34, and a confined pressure interface 5 leading to the confined pressure chamber 34 is provided on the outer cylinder 13; the upper plug 11, the lower plug 14 and the outer cylinder 13 is provided with a sealing ring 4; the inner diameters of the hose 12, the upper plug 11, and the lower plug 14 are the same, an upper plunger 10 is provided on the inner circumference of the hose 12 and the upper plug 11, and a lower plunger 6 is provided on the inner circumference of the hose 12 and the lower plug 14. The upper plunger 10 is provided with a gas-liquid outlet 9, and the gas-liquid outlet 9 is connected to the inner cavity of the hose 12 through a pipeline provided in the upper plunger 10. The lower plunger 6 is provided with a gas-liquid inlet 7, and the gas-liquid inlet 7 is connected to the inner cavity of the hose 12 through a pipeline provided in the lower plunger 6;

[0029] The gas-liquid two-phase flow injection system includes a gas cylinder 1, which is connected to a valve F4, a pressure gauge P4, and a gas-liquid inlet 7 in sequence through pipelines; and also includes a liquid storage tank 2, one end of which is connected to a valve F5, a pipeline between the gas cylinder 1 and the valve F4, a valve F3, and a first liquid source in sequence through pipelines, and the other end of the liquid storage tank 2 is connected to a valve F6, a pipeline between the pressure gauge P4, and the gas-liquid inlet 7 in sequence through pipelines;

[0030] The metering system includes an electronic scale and beaker system 15, a liquid flowmeter 16, a large-range gas flowmeter 17, and a small-range gas flowmeter 18. The gas-liquid outlet 9, valve F10, pressure gauge P2, valve F12, and the beaker of the electronic scale and beaker system 15 are sequentially connected by pipelines, and the beaker in the electronic scale and beaker system 15 is located on the electronic scale; the pipeline between the pressure gauge P2 and valve F12, valve F13, and liquid flowmeter 16 are sequentially connected by pipelines; the pressure gauge P2, valve F11, drying cylinder 19, valve F14, and large-range gas flowmeter 17 are also sequentially connected by pipelines, and the pipeline between the drying cylinder 19 and valve F14, valve F15, and small-range gas flowmeter 18 are sequentially connected by pipelines; further, the liquid flowmeter 16, liquid transfer pump 33, valve F7, and the pipeline between the liquid storage tank 2 and valve F6 are sequentially connected by pipelines;

[0031] The confining pressure loading system includes a confining pressure pump 20, the liquid outlet of the confining pressure pump 20 is connected to the valve F1, the pressure gauge P3 and the confining pressure interface 5 in sequence through a pipeline; the liquid inlet of the confining pressure pump 20 is connected to the valve F2 and the second liquid source in sequence through a pipeline;

[0032] The axial pressure loading system can adopt the existing test loading mechanism, which mainly includes a loading column 3 and a hydraulic loader 35 that controls the loading of the loading body 3. The loading column 3 is connected to the pressure gauge P1, valve F8 and hydraulic loader 35 in sequence through pipelines, and the pipelines, valve F9 and hydraulic source are connected between the valve F8 and the hydraulic loader 35 in sequence through pipelines; since the laboratory loading mechanism is a loading mechanism well known in the art, its details are not repeated here. The loading column 3 is fixedly connected to the upper end of the upper plunger 10 through a clamp 8.

[0033] As a further technical solution of embodiment 1, Figure 3As shown, the confining pressure pump 20 includes a pump head 22 and a plunger 23 that can slide in the pump head 22, and a sealing material 24 is provided between the plunger 23 and the pump head 22; a liquid outlet head 21 is provided at the end of the pump head 22 away from the plunger 23, and a liquid inlet head 31 is circumferentially provided on the pump head 22; a first fixed disk 32a is circumferentially fixed on the side of the pump head 22 close to the plunger 23, and the bottom of the first fixed disk 32a is fixed on the pump seat 27, and a second fixed disk 32b is also fixed on the side of the pump seat 27 away from the first fixed disk 32a, and a guide cross bar 25 is used to connect the first fixed disk 32a and the second fixed disk 32b, and the guide cross bar 25 is arranged along the column The plugs 23 are evenly distributed around the circumference and arranged in parallel with the plunger 23. The side of the plunger 23 away from the pump head 22 is set to a threaded sleeve 26 structure. The threaded sleeve 26 is threadedly connected to the threaded rod 29. The end of the threaded rod 29 away from the threaded sleeve 26 passes through the second fixed disk 32b and is provided with a rotating handle 30. The threaded rod 29 is rotatably connected to the second fixed disk 32b (such as through a bearing). Rotating the threaded rod 29 can make the plunger 23 move into the pump head 22 or away from the pump head 22; the threaded sleeve 26 is evenly circumferentially provided with guide vertical rods 28 corresponding to the guide cross rod 25, and the guide vertical rods are slidably connected to the guide cross rod 25.

[0034] Example 2

[0035] The method for using the device for testing the gas-liquid two-phase seepage mechanical coupling characteristics of the crushed coal rock mass of the first embodiment includes testing the gas phase seepage and mechanical coupling characteristics and testing the liquid phase seepage and mechanical coupling characteristics;

[0036] The gas phase percolation and mechanical coupling characteristic test comprises the following steps:

[0037] A1: Place the autoclave system on the loading platform of the axial pressure loading system. Install spacers between the bottom of the autoclave system and the loading platform as needed. Connect the loading column 2 and the upper plunger 10 through the clamp 8. At this time, all valves are in the closed state.

[0038] A2: Open valves F8 and F9, raise the upper plunger 10, and add the crushed coal and rock sample into the hose 12. Record the parameters of the crushed coal and rock sample at this time, including height, weight, density, particle size, porosity, etc.; insert the upper plunger 10 to the top surface of the coal and rock sample;

[0039] A3: Open valves F1 and F2, apply the designed confining pressure to the crushed coal and rock mass sample through the confining pressure pump 20, and apply the designed axial pressure through the axial pressure loading system at the same time;

[0040] A4: Open valves F4, F10, and F11, and open valve F14 or F15 according to the designed flow rate; open gas cylinder 1 and inject gas into the crushed coal and rock sample at the designed pressure to measure the gas permeability;

[0041] A5: Further increase the confining pressure and axial pressure as needed to measure the permeability;

[0042] A6: After the test, close the gas cylinder 1, release the confining pressure through the confining pressure pump 20, raise the upper plunger 10 to release the axial pressure, remove the crushed coal and rock sample, and close all valves;

[0043] The liquid phase seepage and mechanical coupling characteristic test includes the following steps:

[0044] L1: Place the autoclave system on the loading platform of the axial pressure loading system. Set a spacer between the bottom of the autoclave system and the loading platform as needed. Connect the loading column 2 and the upper plunger 10 through the clamp 8. At this time, all valves are in the closed state (this step can be omitted if the liquid phase permeation and mechanical coupling characteristics test is performed immediately after the gas phase permeation and mechanical coupling characteristics test);

[0045] L2: Open valves F8 and F9, raise the upper plunger 10, add the crushed coal and rock sample into the hose 12, and record the parameters of the crushed coal and rock sample at this time, including height, weight, density, particle size, porosity and other parameters; insert the upper plunger 10 to the top surface of the coal and rock sample;

[0046] L3: Open valves F3, F5, and F7, and turn on the liquid transfer pump 33 to inject the liquid required for the test into the liquid storage tank 2; close valves F3, F5, and F7;

[0047] Open valves F1 and F2, apply the designed confining pressure to the crushed coal and rock mass sample through the confining pressure pump 20, and apply the designed axial pressure through the axial pressure loading system at the same time;

[0048] L4: Open valves F5, F6, and F10, and open valve F12 or valve F13, valve F7, and liquid transfer pump 33 according to the designed flow rate; open gas cylinder 1, and use gas pressure to drive liquid to inject liquid into the crushed coal and rock sample at the set pressure to measure the liquid permeability;

[0049] L5: Further increase the confining pressure and axial pressure as needed to measure the permeability;

[0050] L6: After the test, close the gas cylinder 1, release the confining pressure through the confining pressure pump 20, raise the upper plunger 10 to release the axial pressure, take out the crushed coal and rock sample, and close all valves.

[0051] Of course, the above description is only a preferred embodiment of this patent, and this patent is not limited to the above embodiments. It should be noted that all equivalent substitutions and obvious deformation forms made by any technician familiar with this field under the guidance of this specification fall within the substantive scope of this specification and should be protected by this patent.

Claims

1. A testing device for the mechanical coupling characteristics of gas-liquid two-phase seepage in crushed coal and rock mass, comprising an autoclave system, a gas-liquid two-phase flow injection system, a metering system, a confining pressure loading system, and an axial pressure loading system; characterized in that: The autoclave system includes a coaxially arranged hose and an outer cylinder, an annulus is formed between the hose and the outer cylinder, an upper plug is provided on the upper part of the hose and the outer cylinder, and a lower plug is provided on the lower part of the hose and the outer cylinder, so that the annulus between the hose and the outer cylinder is sealed to form a confined pressure chamber, and a confined pressure interface leading to the confined pressure chamber is provided on the outer cylinder; the hose, the upper plug and the lower plug have the same inner diameter, an upper plunger is provided on the inner circumference of the hose and the upper plug, and a lower plunger is provided on the inner circumference of the hose and the lower plug, a gas-liquid outlet is provided on the upper plunger, and the gas-liquid outlet is connected to the inner cavity of the hose through a pipeline provided in the upper plunger, and a gas-liquid inlet is provided on the lower plunger, and the gas-liquid inlet is connected to the inner cavity of the hose through a pipeline provided in the lower plunger; The gas-liquid two-phase flow injection system includes a gas cylinder, which is connected to valve F4, pressure gauge P4 and gas-liquid inlet in sequence through pipelines; and also includes a liquid storage tank, one end of which is connected to valve F5, the pipeline between the gas cylinder and valve F4, valve F3 and the first liquid source in sequence through pipelines, and the other end of the liquid storage tank is connected to valve F6, pressure gauge P4 and the pipeline between the gas-liquid inlet in sequence through pipelines; The metering system includes an electronic scale and a beaker system, which is connected in sequence by a pipeline to the gas-liquid outlet, valve F10, pressure gauge P2, valve F12, and the beaker of the electronic scale and beaker system; the pipeline between the pressure gauge P2 and valve F12, valve F13, and a liquid flow meter are connected in sequence by a pipeline; the pressure gauge P2, valve F11, drying cylinder, valve F14, and a large-range gas flow meter are also connected in sequence by a pipeline; and the pipeline between the drying cylinder and valve F14, valve F15, and a small-range gas flow meter are connected in sequence by a pipeline; The confining pressure loading system includes a confining pressure pump, the liquid outlet of the confining pressure pump is connected to the valve F1, the pressure gauge P3 and the confining pressure interface in sequence through a pipeline; the liquid inlet of the confining pressure pump is connected to the valve F2 and the second liquid source in sequence through a pipeline; The axial pressure loading system mainly includes a loading column and a hydraulic loading machine that controls the loading of the loading body.

2. The testing device according to claim 1, wherein: A sealing ring is provided between the upper plug, the lower plug and the outer cylinder.

3. The testing device according to claim 1, wherein: Use pipelines to connect the liquid flow meter, liquid transfer pump, valve F7, and the pipeline between the liquid storage tank and valve F6 in sequence.

4. The testing device according to claim 3, wherein: The loading column is connected to the pressure gauge P1, valve F8 and hydraulic loader in sequence through pipelines, and pipelines, valves and hydraulic sources are connected between the valve F8 and the hydraulic loader in sequence through pipelines.

5. The testing device according to claim 1, wherein: The loading column is fixedly connected to the upper end of the upper plunger through a clamp.

6. The testing device according to any one of claims 1 to 5, characterized in that: The confining pressure pump includes a pump head and a plunger that can slide in the pump head; a liquid outlet head is provided at the end of the pump head away from the plunger, and a liquid inlet head is circumferentially provided on the pump head; a first fixed disk is circumferentially fixed on the side of the pump head close to the plunger, and the bottom of the first fixed disk is fixed on the pump seat, and a second fixed disk is also fixed on the side of the pump seat away from the first fixed disk, and the first fixed disk and the second fixed disk are connected by a guide cross bar, and the guide cross bar is distributed along the circumference of the plunger and arranged parallel to the plunger, and the side of the plunger away from the pump head is provided with a threaded sleeve structure, the threaded sleeve is threadedly connected to the threaded rod, and the end of the threaded rod away from the threaded sleeve passes through the second fixed disk and is provided with a rotating handle, and the threaded rod is rotatably connected to the second fixed disk; the threaded sleeve is circumferentially provided with a guide vertical rod corresponding to the guide cross rod, and the guide vertical rod is slidably connected to the guide cross rod.

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