Coal mine underground reservoir similarity simulation test system and coal mine underground reservoir simulation method

Abstract

The present invention provides a similar simulation test system for a coal mine underground reservoir and a coal mine underground reservoir simulation method. The similar simulation test system for a coal mine underground reservoir comprises: a base; a similar material box disposed on the base, the similar material box comprising a box body, a goaf collapse zone simulation layer, and a water-conducting fracture zone simulation layer, the box body having a receiving cavity and a first liquid inlet, a second liquid inlet, a liquid discharge port, and a detection hole all connected to the receiving cavity, the goaf collapse zone simulation layer and the water-conducting fracture zone simulation layer both being disposed within the receiving cavity; a water source supply assembly comprising a first and a second liquid supply device, the first liquid supply device being connected to the first liquid inlet, and the second liquid supply device being connected to the second liquid inlet; a water pressure monitoring device for detecting the water pressure at the detection hole; and a water sample collection and testing device for detecting the water quality index of the water sample in the liquid discharge port. The present invention solves the problem in the prior art of being unable to obtain the water-rock interaction process within a coal mine underground reservoir.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mine groundwater and goaf environment, in particular to a coal mine groundwater reservoir similarity simulation test system and a coal mine groundwater reservoir simulation method. Background Art

[0002] Currently, coal, as my country's primary energy source, accounts for 76% and 66% of primary energy production and consumption, respectively. Coal mining in my country destroys approximately 8 billion tons of groundwater annually, and the utilization rate of mine water is only around 25%. This loss of mine water resources is equivalent to 60% of my country's annual industrial and domestic water shortage (10 billion tons). To achieve green and efficient utilization of mine water, the academic concept of "groundwater reservoir storage" and the concept of underground mine water storage and utilization have been proposed. This involves utilizing coal mine goafs for water storage, connecting safety coal pillars with artificial dams to form reservoirs. This breaks away from the previous passive water conservation mining method of "blocking" groundwater, and opens up new avenues for coal development and water resource conservation.

[0003] However, due to the closed nature and complexity of coal mine underground reservoirs, the water environment characteristics of underground reservoirs (such as water inlet and outlet flow rates, hydraulic residence time and head pressure) and water-rock interactions within the reservoirs are still unclear, which in turn affects the scientific management and efficient utilization of underground reservoir water resources. Summary of the Invention

[0004] The main purpose of the present invention is to provide a coal mine underground reservoir similarity simulation test system and a coal mine underground reservoir simulation method to solve the problem in the prior art that the water-rock interaction process in the coal mine underground reservoir cannot be obtained.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a similar simulation test system for a coal mine underground water reservoir is provided, comprising: a base; a similar material box, arranged on the base, the similar material box comprising a box body, a goaf collapse zone simulation layer and a water-conducting fracture zone simulation layer, the box body having a accommodating cavity and a first liquid inlet, a second liquid inlet, a discharge port, and a detection hole, all of which are connected to the accommodating cavity, the goaf collapse zone simulation layer and the water-conducting fracture zone simulation layer are both arranged in the accommodating cavity and located below the water-conducting fracture zone simulation layer; a water source supply component, comprising a first liquid supply device and a second liquid supply device, the first liquid supply device being connected to the first liquid inlet and used for supplying liquid to the goaf collapse zone simulation layer, the second liquid supply device being connected to the second liquid inlet and used for supplying liquid to the water-conducting fracture zone simulation layer; a water pressure monitoring device, used for detecting the water pressure at the detection hole; a water sample collection and testing device, used for detecting the water quality index of the water sample in the discharge port.

[0006] Furthermore, the simulated layer of the goaf collapse zone is formed by a mixture of coal gangue and fine gravel, and the simulated layer of the water-conducting fracture zone includes: multiple layers of mica sheets; a mixture arranged between adjacent mica sheets on both sides, and the mixture is formed by a mixture of sand and talcum powder.

[0007] Furthermore, the water pressure monitoring device includes: a copper tube, which is inserted into the detection hole, and the first end of the copper tube extends into the accommodating cavity; a hose, the first end of the hose is connected to the second end of the copper tube; and a water pressure sensor, which is arranged in the second end of the hose to detect the water pressure in the accommodating cavity.

[0008] Furthermore, the water sample collection and testing device also includes: a sampling tube for collecting water samples in the drain port; a timer for timing; and a water sample tester for detecting water quality indicators of the water sample within a preset time period.

[0009] Furthermore, the first liquid supply device includes: a first water storage structure; a first cache structure; a first traction member connected to the first cache structure; a first pipeline connected to both the first water storage structure and the first cache structure; a first pump body arranged on the first pipeline for pumping the liquid in the first water storage structure into the first cache structure; a second pipeline connected to both the first cache structure and the first liquid inlet; a third pipeline connected to both the first water storage structure and the first cache structure; a first control valve arranged on the second pipeline for controlling the on-off state of the second pipeline, the flow rate and the flow rate of the liquid in the second pipeline.

[0010] Furthermore, the second liquid supply device includes: a second water storage structure; a second cache structure; a second traction member connected to the second cache structure; a fourth pipeline connected to both the second water storage structure and the second cache structure; a second pump body arranged on the fourth pipeline for pumping the liquid in the second water storage structure into the second cache structure; a fifth pipeline connected to both the second cache structure and the second liquid inlet; a sixth pipeline connected to both the second water storage structure and the second cache structure; a second control valve arranged on the fifth pipeline for controlling the on-off state of the fifth pipeline, the flow rate and the flow rate of the liquid in the fifth pipeline.

[0011] Furthermore, the coal mine underground water reservoir similarity simulation test system also includes: a seventh pipeline; a recovery structure, the recovery structure is connected to the drain port through the seventh pipeline; and / or a ruler, which is arranged on the side of the box.

[0012] According to another aspect of the present invention, a method for simulating a coal mine underground reservoir is provided, which is applicable to the above-mentioned similar simulation test system for coal mine underground reservoirs. The method for simulating a coal mine underground reservoir comprises: controlling a first liquid supply device of the similar simulation test system for coal mine underground reservoirs to supply liquid into a box, controlling a second liquid supply device to supply liquid into the box, detecting the sealing of the box, and opening a drain port of the box after a first preset time period to drain the liquid from the box; laying a simulated layer of a goaf collapse zone and a simulated layer of a water-conducting fracture zone in the box in sequence to fill the box; and After the simulated layer of the fracture zone has been compacted for n days, the first liquid supply device is controlled to supply liquid to the simulated layer of the collapse zone in the goaf, and the second liquid supply device is controlled to supply liquid to the simulated layer of the water-guiding fracture zone; tracers are added to the first liquid supply device and the second liquid supply device, and the water quality index and tracer concentration of the water sample in the drainage port are tested using a water sample collection and testing device at intervals of a second preset time period, and a curve showing the change of tracer concentration over time is drawn; when the tracer concentration reaches the preset concentration value, the main water-rock interaction processes occurring in the box are analyzed based on the water quality test results of the box inlet and outlet combined with the principles of hydrogeochemistry.

[0013] Furthermore, before adding the tracer into the first liquid supply device and the second liquid supply device, the height of the first buffer structure of the first liquid supply device and / or the height of the second buffer structure of the second liquid supply device are adjusted.

[0014] Furthermore, before adding the tracer into the first liquid supply device and the second liquid supply device, at least one of the closing degrees of the first control valve, the second control valve and the third control valve of the similar simulation test system of the coal mine underground water reservoir is adjusted.

[0015] Applying the technical solution of the present invention, a similar simulation test system for a coal mine underground water reservoir includes a similar material box, a water source supply component, a water pressure monitoring device, and a water sample collection and testing device. The similar material box includes a box body, a simulated layer of a goaf collapse zone, and a simulated layer of a water-conducting fracture zone. The water source supply component includes a first liquid supply device and a second liquid supply device. The first liquid supply device is connected to the first liquid inlet of the similar material box and is used to supply liquid to the simulated layer of the goaf collapse zone. The second liquid supply device is connected to the second liquid inlet of the box body and is used to supply liquid to the simulated layer of the water-conducting fracture zone. The water pressure monitoring device is used to detect the water pressure in the similar material box, and the water sample collection and testing device is used to detect the water quality indicators of the water sample in the drainage port. In this way, the coal mine underground water reservoir similarity simulation test system can more realistically simulate the coal mine underground water reservoir inlet and outlet flow rate, water pressure, hydraulic residence time and water-rock interaction process, providing a scientific theoretical basis for the safe, efficient and green utilization of coal mine water, thereby solving the problem that the existing technology cannot obtain the water-rock interaction process in the coal mine underground reservoir, making it easier for staff to clearly observe the evolution of water flow in the underground reservoir, monitor the reservoir inlet and outlet flow rate and the head change in the reservoir in real time, and dynamically detect the water quality changes in the reservoir. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0017] Figure 1 It shows a structural schematic diagram of an embodiment of a similar simulation test system for a coal mine underground reservoir according to the present invention;

[0018] Figure 2 Shown Figure 1 A rear view of a similar material box of a similar simulation test system for a coal mine underground water reservoir;

[0019] Figure 3 Shown Figure 1 A schematic diagram of the structure of the water pressure monitoring device of the similar simulation test system of the coal mine underground reservoir;

[0020] Figure 4 Shown Figure 1 The carmine concentration variation curve over time in a similar simulation test system of a coal mine underground reservoir;

[0021] Figure 5 A flow chart showing an embodiment of a method for simulating underground water reservoirs in a coal mine according to the present invention is shown.

[0022] The above drawings include the following reference numerals:

[0023] 1. Similar material box; 2. Left filter plate; 3. Right filter plate; 4. Sealing ring; 5. Pressure cover plate; 6. Bolt; 7. Box back plate; 8. Inspection hole; 9. Sponge cover; 10. Flower tube; 11. Copper tube; 12. Hose; 13. First thin iron wire; 14. Second thin iron wire; 15. Water pressure sensor; 16. Water-conducting fracture zone simulation layer; 17. Goaf collapse zone simulation layer; 18. Scale; 19. Base; 20. Wheel body; 21. First flow meter; 22. First control valve; 23. Third pipeline; 24. Second pipeline; 25. First pipeline; 26. First buffer structure; 27. First baffle; 28. First traction member; 29. ​​First pulley; 30. First pump body; 31. First water storage structure; 32. Fifth pipeline; 33. Second flow meter; 34. Second control valve; 35. Fourth pipeline; 36. Sixth pipeline; 37. Second cache structure; 38. Second baffle; 39. Second traction member; 40. Second pulley; 41. Second pump body; 42. Second water storage structure; 43. Seventh pipeline; 44. Third flow meter; 45. Third control valve; 46. Recovery structure; 47. Timer; 48. Sampling tube; 49. Water sample tester; 50. Data acquisition line; 51. Data acquisition box; 52. Data output line; 53. Computer; 60. First liquid supply device; 70. Second liquid supply device; 80. Water pressure monitoring device; 90. Water sample collection and testing device. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0025] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0026] In the present invention, unless otherwise specified, directional words such as "up" and "down" are generally used with respect to the directions shown in the drawings, or with respect to the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "left" and "right" are generally used with respect to the left and right shown in the drawings; "inside" and "outside" refer to the inside and outside relative to the outline of each component itself, but the above directional words are not used to limit the present invention.

[0027] In order to solve the problem in the prior art that the water-rock interaction process in a coal mine underground reservoir cannot be obtained, the present application provides a coal mine underground reservoir similarity simulation test system and a coal mine underground reservoir simulation method.

[0028] like Figures 1 to 3As shown, the similar simulation test system for a coal mine underground water reservoir includes a base 19, a similar material box 1, a water supply assembly, a water pressure monitoring device 80, and a water sample collection and testing device 90. The similar material box 1 is mounted on the base 19 and includes a box body, a simulated layer 17 of a goaf collapse zone, and a simulated layer 16 of a water-conducting fracture zone. The box body has a receiving cavity and a first liquid inlet, a second liquid inlet, a liquid discharge port, and a detection hole 8, all of which are connected to the receiving cavity. The simulated layer 17 of the goaf collapse zone and the simulated layer 16 of the water-conducting fracture zone are both disposed within the receiving cavity and located below the simulated layer 16 of the water-conducting fracture zone. The water supply assembly includes a first liquid supply device 60 and a second liquid supply device 70. The first liquid supply device 60 is connected to the first liquid inlet and is used to supply liquid to the simulated layer 17 of the goaf collapse zone. The second liquid supply device 70 is connected to the second liquid inlet and is used to supply liquid to the simulated layer 16 of the water-conducting fracture zone. The water pressure monitoring device 80 is used to detect the water pressure at the detection hole 8. The water sample collection and testing device 90 is used to detect the water quality index of the water sample in the drain outlet.

[0029] Applying the technical solution of this embodiment, the similar simulation test system of the coal mine underground water reservoir includes a similar material box 1, a water source supply component, a water pressure monitoring device 80 and a water sample collection and testing device 90. The similar material box 1 includes a box body, a simulated layer 17 of the goaf collapse zone and a simulated layer 16 of the water-conducting fracture zone. The water source supply component includes a first liquid supply device 60 and a second liquid supply device 70. The first liquid supply device 60 is connected to the first liquid inlet of the similar material box and is used to supply liquid to the simulated layer 17 of the goaf collapse zone. The second liquid supply device 70 is connected to the second liquid inlet of the box body and is used to supply liquid to the simulated layer 16 of the water-conducting fracture zone. The water pressure monitoring device 80 is used to detect the water pressure in the similar material box, and the water sample collection and testing device 90 is used to detect the water quality index of the water sample in the drainage port. In this way, the coal mine underground water reservoir similarity simulation test system can more realistically simulate the coal mine underground water reservoir inlet and outlet flow rate, water pressure, hydraulic residence time and water-rock interaction process, providing a scientific theoretical basis for the safe, efficient and green utilization of coal mine water, thereby solving the problem that the existing technology cannot obtain the water-rock interaction process in the coal mine underground reservoir, making it easier for staff to clearly observe the evolution of water flow in the underground reservoir, monitor the reservoir inlet and outlet flow rate and the head change in the reservoir in real time, and dynamically detect the water quality changes in the reservoir.

[0030] In this embodiment, the similar material box 1 further includes a pressure-bearing cover plate 5 disposed on the box body. A sealing ring 4 is disposed between the box body and the pressure-bearing cover plate 5. The box body and the pressure-bearing cover plate 5 are connected and fastened by bolts 6. A wheel body 20 is disposed at the lower end of the base 19 to drive the similar material box 1 and the base 19 to move.

[0031] In this embodiment, the length of the similar material box 1 is 1.5 to 2.0 m, the height of the similar material box 1 is 0.6 to 1.0 m, and the width of the similar material box 1 is 0.5 to 0.8 m.

[0032] In this embodiment, a left filter plate 2 and a right filter plate 3 are provided in the box.

[0033] In this embodiment, the simulated goaf collapse zone layer 17 is formed from a mixture of coal gangue and fine gravel, while the simulated water-conducting fracture zone layer 16 comprises multiple layers of mica sheets and a mixture. The mixture is disposed between adjacent mica sheets and is formed from a mixture of sand, gravel, and talcum powder. Thus, the simulated goaf collapse zone layer 17 simulates the coal mine goaf and collapse zone, while the simulated water-conducting fracture zone layer 16 simulates the water-conducting fracture zone in the coal seam roof.

[0034] like Figure 3 As shown, the water pressure monitoring device 80 includes a copper tube 11, a flexible hose 12, and a water pressure sensor 15. The copper tube 11 is inserted into the detection hole 8, with the first end of the copper tube 11 extending into the receiving chamber. The first end of the flexible hose 12 is connected to the second end of the copper tube 11. The water pressure sensor 15 is located within the second end of the flexible hose 12 to detect the water pressure within the receiving chamber.

[0035] In this embodiment, the detection hole 8 is located on the rear wall of the box. The end of the copper tube 11 is a flower tube 10 and is protected by a sponge cover 9. The end of the copper tube 11 passes through the detection hole 8 and is connected to one end of a hose 12. The other end of the hose 12 is connected to the probe of the water pressure sensor 15. The inside of the connection between the two ends of the hose 12 is sealed with silicone. The outside of the connection between the two ends of the hose 12 is tied with a first thin iron wire 13 and a second thin iron wire 14 respectively. The contact area between the copper tube 11 and the detection hole 8 is sealed with silicone and glass glue. There are multiple detection holes 8, and the multiple detection holes 8 are spaced along the length and height of the box. The detection holes 8 are arranged on the back panel 7 of the box in an evenly spaced grid. The number of detection holes 8 is 30 to 40.

[0036] Specifically, the water pressure sensor 15 is connected to a data acquisition box 51 via a data acquisition line 50 , and the data acquisition box 51 transmits the collected data to a computer 53 via a data output line 52 .

[0037] Optionally, the copper tube 11 is a retractable hollow copper tube.

[0038] Optionally, the hose 12 is a leather hose.

[0039] like Figure 1 As shown, the water sampling and testing device 90 also includes a sampling tube 48, a timer 47, and a water sample tester 49. The sampling tube 48 is used to collect water samples from the drainage outlet. The timer 47 is used to measure time, and the water sample tester 49 is used to test the water quality indicators of the water sample within a preset time period. Thus, the sampling tube 48 is used to collect water samples from the drainage outlet, the timer 47 is used to record the sampling time, and the water sample tester 49 is used to test the physical and chemical indicators and content of the water in the sampling tube 48.

[0040] like Figure 1 As shown, the first liquid supply device 60 includes a first water storage structure 31, a first buffer structure 26, a first traction member 28, a first pipeline 25, a first pump body 30, a second pipeline 24, a third pipeline 23, and a first control valve 22. The first traction member 28 is connected to the first buffer structure 26, and the first pipeline 25 is in communication with both the first water storage structure 31 and the first buffer structure 26. The first pump body 30 is disposed on the first pipeline 25 and is used to pump liquid within the first water storage structure 31 into the first buffer structure 26. The second pipeline 24 is in communication with both the first buffer structure 26 and the first liquid inlet, and the third pipeline 23 is in communication with both the first water storage structure 31 and the first buffer structure 26. The first control valve 22 is disposed on the second pipeline 24 and is used to control at least one of the on / off state of the second pipeline 24, the flow rate, and the flow rate of the liquid within the second pipeline 24. Thus, the height of the first buffer structure 26 is adjusted by the first traction member 28, thereby controlling the water head within the first buffer structure 26. At the same time, the above arrangement makes the structure of the first liquid supply device 60 simpler, easier to process and realize, and reduces the processing cost and difficulty of the first liquid supply device 60.

[0041] Specifically, the first pipeline 25 is a water pumping pipe, the second pipeline 24 is a water inlet pipe, and the third pipeline 23 is a return pipe. The bottom of the first cache structure 26 returns water to the first water storage structure 31 through the third pipeline 23. The first water storage structure 31 transports water to the first cache structure 26 through the first pump body 30 and the first pipeline 25. The bottom of the first cache structure 26 is connected to the first liquid inlet located at the left end of the box through the second pipeline 24. The first flowmeter 21 and the first control valve 22 are installed on the second pipeline 24.

[0042] Optionally, the first traction member 28 is a steel wire rope. The first liquid supply device 60 further includes a first pulley 29, a steel wire rope is wound around the first pulley 29, and one end of the steel wire rope is connected to the first buffer structure 26. The staff can adjust the height of the first buffer structure 26 by dragging the other end of the steel wire rope.

[0043] Optionally, the first pump body 30 is a submersible pump.

[0044] like Figure 1 As shown, the first liquid supply device 60 also includes a first baffle 27, which is arranged in the first cache structure 26 to separate the inner cavity of the first cache structure 26 into two independent chambers, one chamber is connected to the first pipeline 25 and the second pipeline 24, and the other chamber is connected to the third pipeline 23.

[0045] like Figure 1As shown, the second liquid supply device 70 includes a second water storage structure 42, a second buffer structure 37, a second traction member 39, a fourth pipeline 35, a second pump body 41, a fifth pipeline 32, a sixth pipeline 36, and a second control valve 34. The second traction member 39 is connected to the second buffer structure 37. The fourth pipeline 35 is in communication with both the second water storage structure 42 and the second buffer structure 37. The second pump body 41 is disposed on the fourth pipeline 35 to pump liquid within the second water storage structure 42 into the second buffer structure 37. The fifth pipeline 32 is in communication with both the second buffer structure 37 and the second liquid inlet. The sixth pipeline 36 is in communication with both the second water storage structure 42 and the second buffer structure 37. The second control valve 34 is disposed on the fifth pipeline 32 to control at least one of the on / off state of the fifth pipeline 32, the flow rate, and the flow rate of the liquid within the fifth pipeline 32.

[0046] Specifically, the fourth pipeline 35 is a water pumping pipe, the fifth pipeline 32 is a water inlet pipe, and the sixth pipeline 36 is a return pipe. The bottom of the second cache structure 37 returns water to the second water storage structure 42 through the sixth pipeline 36. The second water storage structure 42 transports water to the second cache structure 37 through the second pump body 41 and the fourth pipeline 35. The bottom of the second cache structure 37 is connected to the second liquid inlet located at the right end of the box through the fifth pipeline 32. The second flowmeter 33 and the second control valve 34 are provided on the fifth pipeline 32.

[0047] Optionally, the second traction member 39 is a steel wire rope. The second liquid supply device 70 further includes a second pulley 40, a steel wire rope is wound around the second pulley 40, and one end of the steel wire rope is connected to the second buffer structure 37. The staff can adjust the height of the second buffer structure 37 by dragging the other end of the steel wire rope.

[0048] Optionally, the second pump body 41 is a submersible pump.

[0049] like Figure 1 As shown, the second liquid supply device 70 also includes a second baffle 38, which is arranged in the second cache structure 37 to separate the inner cavity of the second cache structure 37 into two independent chambers, one chamber is connected to the fourth pipeline 35 and the fifth pipeline 32, and the other chamber is connected to the sixth pipeline 36.

[0050] like Figure 1 As shown, the similar simulation test system for a coal mine underground water reservoir also includes a seventh pipeline 43, a recovery structure 46, and / or a scale 18. The recovery structure 46 is connected to the drain port via the seventh pipeline 43, and the scale 18 is located on the side of the tank. Thus, the recovery structure 46 recovers the water and rock discharged from the tank, thereby preventing environmental pollution and material waste.

[0051] In this embodiment, the seventh pipeline 43 is a water outlet pipe, and the drain port is located at the right bottom of the box body. A third flow meter 44 and a third control valve 45 are provided on the seventh pipeline 43 to monitor the flow or flow rate in the seventh pipeline 43 through the third flow meter 44. The third control valve 45 is used to control the on and off state of the seventh pipeline 43.

[0052] In this embodiment, the display value of the first flowmeter 21 is regulated by the closing degree of the first control valve 22 and the power of the first pump body 30, the display value of the second flowmeter 33 is regulated by the closing degree of the second control valve 34 and the power of the second pump body 41, and the display value of the third flowmeter 44 is mainly regulated by the closing degree of the third control valve 45.

[0053] In this embodiment, the scale 18 is a graduated ruler, which is arranged on the left side of the front of the box and is used to observe the water head height in the box, and complements the water pressure monitoring device 80.

[0054] like Figure 5 As shown, the present application also provides a coal mine underground reservoir simulation method, which is applicable to the above-mentioned coal mine underground reservoir similarity simulation test system. The coal mine underground reservoir simulation method includes:

[0055] Controlling a first liquid supply device of a similar simulation test system for a coal mine underground reservoir to supply liquid into a tank, controlling a second liquid supply device to supply liquid into the tank, detecting the sealing of the tank, and opening a drain port of the tank after a first preset time period to drain the liquid from the tank;

[0056] Lay the simulated layer of the goaf collapse zone and the simulated layer of the water-conducting fracture zone in sequence into the box to fill the box;

[0057] After the simulated layer of the goaf collapse zone and the simulated layer of the water-conducting fracture zone have been compacted for n days, the first liquid supply device is controlled to supply liquid to the simulated layer of the goaf collapse zone and the second liquid supply device is controlled to supply liquid to the simulated layer of the water-conducting fracture zone;

[0058] Adding a tracer into the first liquid supply device and the second liquid supply device, testing the water quality index and tracer concentration of the water sample in the drain outlet using a water sampling and testing device at intervals of a second preset time period, and drawing a curve showing the change of the tracer concentration over time;

[0059] When the tracer concentration reaches the preset concentration value, the main water-rock interaction processes occurring in the box are analyzed based on the water quality test results of the box inlet and outlet combined with the principles of hydrogeochemistry.

[0060] In this embodiment, before adding the tracer into the first liquid supply device and the second liquid supply device, the height of the first buffer structure of the first liquid supply device and / or the height of the second buffer structure of the second liquid supply device are adjusted.

[0061] In this embodiment, before adding the tracer into the first liquid supply device and the second liquid supply device, at least one of the closing degree of the first control valve, the closing degree of the second control valve and the closing degree of the third control valve of the coal mine underground water reservoir similar simulation test system is adjusted.

[0062] Specifically, the specific steps of the coal mine underground reservoir simulation method are as follows:

[0063] Step 1: Start the first pump 30 and the second pump 41, and adjust the water head height of the first buffer structure 26 and the second buffer structure 37. Then, open the first control valve 22 and the second control valve 34 and close the third control valve 45. Check the sealing of the similar material box 1, the operation of the water supply assembly, and the water pressure monitoring device 80. Adjust the power of the first pump 30 and the second pump 41 and the opening degree of the first control valve 22 and the second control valve 34. At the same time, open the third control valve 45 and check the operation of each system device.

[0064] Step 2: Close the first pump body 30, the second pump body 41, the first control valve 22, and the second control valve 34. After the water in the similar material box 1 is completely drained, open the pressure cover plate 5 of the similar material box 1. First, lay the goaf collapse zone simulation layer 17 composed of materials such as coal gangue and fine gravel at the bottom of the similar material box 1 to simulate the coal mine goaf and collapse zone. Then, lay the water-conducting fracture zone simulation layer 16 composed of materials such as sand, talcum powder, mica flakes, and a binder on top of the goaf collapse zone simulation layer 17 to simulate the water-conducting fracture zone of the coal seam roof. During the laying process of the goaf collapse zone simulation layer 17 and the water-conducting fracture zone simulation layer 16, pay attention to protecting the copper tube 11, and seal the contact area between the copper tube 11 and the detection hole 8 again with silicone and glass glue.

[0065] Step 3: After similar material box 1 is filled and compacted for three days, cover it with the pressure-bearing cover plate 5 to reseal it. Restart the first pump 30 and the second pump 41, adjust the water head height of the first and second buffer structures 26 and 37, and slowly open the first, second, and third control valves 22, 34, and 45 to adjust the water inlet and outlet rates of similar material box 1. This simulates the water flow evolution in a coal mine underground reservoir under multi-source recharge conditions. Use a water sampling and testing device to test the water quality of the first and second buffer structures 26 and 37.

[0066] Step 4: Add appropriate amounts of carmine as a tracer into the first buffer structure 26 and the second buffer structure 37 respectively, and start timing using the timer 47. Use the sampling tube 48 to collect water samples at the outlet of the seventh pipeline 43 every 1 minute, use the water sample tester 49 to test the water quality index and carmine concentration of the water sample, and draw a curve of the change of carmine concentration over time, as shown in FIG. Figure 4 shown.

[0067] like Figure 4 As shown, C f represents the peak concentration of carmine tracer in the water at the outlet of the similar material box during the tracer test, T f Indicates that the carmine tracer concentration reaches the peak concentration C during the tracer test. f The time it takes for the hydraulic retention time to t Indicates that the carmine tracer concentration in the water at the outlet of the similar material box reached a peak value C during the tracer test. f After that, it dropped to 0.2C f The time that has passed is the end time of the tracer test.

[0068] Step 5: Wait until the carmine concentration at the drain outlet of similar material box 1 reaches its maximum value C f When the hydraulic retention time T of the similar material box 1 reaches 20%, the test is stopped and all the data collected in the process are imported into the analysis system to analyze and calculate the hydraulic retention time T of the similar material box 1. f .like Figure 4 As shown, based on the water quality test results of the inlet and outlet water of the similar material box 1 and combined with the principles of hydrogeochemistry, the main water-rock interaction processes occurring in the similar material box 1 are analyzed.

[0069] Step 6: According to steps 1 to 5, change the height of the first cache structure 26 and the second cache structure 37, adjust the closing degree of the first control valve 22, the second control valve 34 and the third control valve 45, and simulate the influence of different inlet and outlet water flow rates, the proportion of supply water sources and the head height in the reservoir on the hydraulic residence time and water purification effect of the coal mine underground reservoir.

[0070] Step 7: After the test is completed, close the first pump body 30, the second pump body 41, the first control valve 22, the second control valve 34, the data acquisition box 51 and the computer 53, keep the third control valve 45 continuously open, and open the pressure cover plate 5 after the water in the similar material box 1 is drained. Take out the water-conducting fracture zone simulation layer 16 and the goaf collapse zone simulation layer 17 in the similar material box 1 layer by layer, while paying attention to protecting the copper tube 11. Finally, conduct a comprehensive inspection and cleaning of the test device.

[0071] In this embodiment, the first flow meter 21, the second flow meter 33 and the third flow meter 44 are used to monitor and record the inlet and outlet water flow of the similar material box 1 in real time, the water pressure monitoring device 80 is used to monitor the head change in the similar material box 1 in real time, and the water sample collection and testing device 90 is used to detect the water quality indicators and carmine concentration changes at the outlet of the seventh pipeline 43.

[0072] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0073] The similarity simulation test system for coal mine underground water reservoirs includes a similarity material box, a water supply assembly, a water pressure monitoring device, and a water sampling and testing device. The similarity material box includes a box body, a simulated layer of the goaf collapse zone, and a simulated layer of the water-conducting fracture zone. The water supply assembly includes a first liquid supply device and a second liquid supply device. The first liquid supply device is connected to the first liquid inlet of the similarity material box and is used to supply liquid to the simulated layer of the goaf collapse zone. The second liquid supply device is connected to the second liquid inlet of the box body and is used to supply liquid to the simulated layer of the water-conducting fracture zone. The water pressure monitoring device is used to detect the water pressure in the similarity material box, and the water sampling and testing device is used to detect the water quality indicators of the water sampled from the drainage outlet. In this way, the coal mine underground water reservoir similarity simulation test system can more realistically simulate the coal mine underground water reservoir inlet and outlet flow rate, water pressure, hydraulic residence time and water-rock interaction process, providing a scientific theoretical basis for the safe, efficient and green utilization of coal mine water, thereby solving the problem that the existing technology cannot obtain the water-rock interaction process in the coal mine underground reservoir, making it easier for staff to clearly observe the evolution of water flow in the underground reservoir, monitor the reservoir inlet and outlet flow rate and the head change in the reservoir in real time, and dynamically detect the water quality changes in the reservoir.

[0074] Obviously, the embodiments described above are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0075] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, tasks, devices, components and / or combinations thereof.

[0076] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0077] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for simulating underground water reservoirs in coal mines, characterized in that: Used in a similar simulation test system for a coal mine underground reservoir, the coal mine underground reservoir simulation method includes: controlling a first liquid supply device of the coal mine underground water reservoir similarity simulation test system to supply liquid into a box, controlling a second liquid supply device to supply liquid into the box, detecting the sealing of the box, and opening a drain port of the box after a first preset time period to drain the liquid from the box; Laying a simulated layer of the goaf collapse zone and a simulated layer of the water-conducting fracture zone in sequence into the box to fill the box; After the simulated layer of the goaf collapse zone and the simulated layer of the water-conducting fracture zone have been compacted for n days, the first liquid supply device is controlled to supply liquid into the simulated layer of the goaf collapse zone and the second liquid supply device is controlled to supply liquid into the simulated layer of the water-conducting fracture zone; Adding a tracer into the first liquid supply device and the second liquid supply device, testing the water quality index and tracer concentration of the water sample in the drain outlet using a water sampling and testing device at intervals of a second preset time period, and plotting a curve showing the change of the tracer concentration over time; When the tracer concentration reaches a preset concentration value, the water-rock interaction process occurring in the box is analyzed based on the water quality test results of the box inlet and outlet combined with the principles of hydrogeochemistry; Before adding the tracer into the first liquid supply device and the second liquid supply device, adjusting the height of the first buffer structure of the first liquid supply device and / or the height of the second buffer structure of the second liquid supply device; The coal mine underground reservoir similarity simulation test system includes: Base (19); A similar material box (1) is arranged on the base (19), the similar material box (1) comprising a box body, a goaf collapse zone simulation layer (17) and a water-conducting fracture zone simulation layer (16), the box body having a receiving cavity and a first liquid inlet, a second liquid inlet, a liquid discharge port, and a detection hole (8) all connected to the receiving cavity, the goaf collapse zone simulation layer (17) and the water-conducting fracture zone simulation layer (16) are both arranged in the receiving cavity, and the goaf collapse zone simulation layer (17) is located below the water-conducting fracture zone simulation layer (16); A water supply assembly comprises a first liquid supply device (60) and a second liquid supply device (70), wherein the first liquid supply device (60) is connected to the first liquid inlet and is used to supply liquid to the simulated layer (17) of the goaf collapse zone, and the second liquid supply device (70) is connected to the second liquid inlet and is used to supply liquid to the simulated layer (16) of the water-conducting fracture zone; A water pressure monitoring device (80) for detecting the water pressure at the detection hole (8); A water sample collection and testing device (90) is used to detect water quality indicators of the water sample in the drainage port; The water pressure monitoring device (80) comprises: A copper tube (11) is inserted into the detection hole (8), and a first end of the copper tube (11) extends into the accommodating cavity; A hose (12), wherein a first end of the hose (12) is connected to a second end of the copper tube (11); A water pressure sensor (15) is arranged in the second end of the hose (12) and is used to detect the water pressure in the accommodating cavity.

2. The coal mine underground reservoir simulation method according to claim 1, characterized in that: Before adding the tracer into the first liquid supply device and the second liquid supply device, at least one of the closing degree of the first control valve, the closing degree of the second control valve and the closing degree of the third control valve of the coal mine underground water reservoir similarity simulation test system is adjusted.

3. The coal mine underground reservoir simulation method according to claim 1, characterized in that: The goaf collapse zone simulation layer (17) is formed by mixing coal gangue and fine gravel, and the water-conducting fracture zone simulation layer (16) includes: Multilayer mica sheets; The mixture is arranged between the adjacent mica sheets on both sides, and the mixture is formed by mixing sand and talcum powder.

4. The coal mine underground reservoir simulation method according to claim 1, characterized in that: The water sample collection and testing device (90) further comprises: a sampling tube (48) for collecting water samples from the drainage port; A timer (47) for timing; The water sample tester (49) is used to detect the water quality index of the water sample within a preset time period.

5. The coal mine underground reservoir simulation method according to claim 1, characterized in that: The first liquid supply device (60) comprises: First water storage structure (31); First cache structure (26); a first traction member (28) connected to the first cache structure (26); a first pipeline (25) in communication with both the first water storage structure (31) and the first buffer structure (26); A first pump body (30) is provided on the first pipeline (25) and is used for pumping liquid in the first water storage structure (31) into the first buffer structure (26); a second pipeline (24) communicating with both the first buffer structure (26) and the first liquid inlet; a third pipeline (23) communicating with both the first water storage structure (31) and the first buffer structure (26); The first control valve (22) is provided on the second pipeline (24) to control at least one of the on-off state of the second pipeline (24), the flow rate and the flow rate of the liquid in the second pipeline (24).

6. The coal mine underground reservoir simulation method according to claim 1, characterized in that: The second liquid supply device (70) comprises: Second water storage structure (42); Second cache structure (37); a second traction member (39) connected to the second cache structure (37); a fourth pipeline (35) communicating with both the second water storage structure (42) and the second buffer structure (37); a second pump body (41), arranged on the fourth pipeline (35), and used for pumping the liquid in the second water storage structure (42) into the second buffer structure (37); a fifth pipeline (32) communicating with both the second buffer structure (37) and the second liquid inlet; a sixth pipeline (36) communicating with both the second water storage structure (42) and the second buffer structure (37); The second control valve (34) is provided on the fifth pipeline (32) to control at least one of the on-off state of the fifth pipeline (32), the flow rate and the flow rate of the liquid in the fifth pipeline (32).

7. The coal mine underground reservoir simulation method according to claim 1, characterized in that: The coal mine underground reservoir similarity simulation test system also includes: seventh pipeline (43); a recovery structure (46), the recovery structure (46) being in communication with the liquid discharge port via the seventh pipeline (43); and / or, A scale (18) is arranged on the side of the box.

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