A physical simulation experiment device for coal mining space carbon dioxide storage

Abstract

The present application belongs to the field of coal mine physical simulation experiment device, in particular to a physical simulation experiment device for coal mine mining space carbon dioxide storage; the physical simulation experiment device is sequentially and spacedly provided with a plurality of barrier structures from left to right in the upper open box shell, the barrier structures isolate a plurality of cavities, the second cavity is used for simulating the mined-out area for storing carbon dioxide, the first cavity is used for simulating the adjacent mined-out area, the barrier structure between the first cavity and the second cavity adopts the coal seam plate for simulating the section coal pillar, and the rest of the barrier structures adopt the rock stratum plate for simulating the upper curved subsidence zone of the mined-out area; the upper part of the box shell is fixed with the first rubber pad and the cover plate. The physical simulation experiment device can simultaneously simulate the vertical and horizontal mining space of the coal mine and the migration of carbon dioxide in the above mining space during the carbon dioxide storage process, and the physical simulation experiment device has high sealing performance.

Description

Technical Field

[0001] This invention belongs to the field of physical simulation experimental devices for coal mines, and specifically relates to a physical simulation experimental device for carbon dioxide sequestration in coal mine mining space. Background Technology

[0002] Carbon dioxide sequestration is an important technological approach for the low-carbon utilization of fossil energy, and the underground mining space of closed mines provides an excellent location for carbon dioxide sequestration. After mining, the overall structure of the mine strata differs significantly from that of intact strata. Based on the distribution of fractures, the mined-out strata can be divided into three parts from the goaf to the surface: the caving zone, the fracture zone, and the flexural subsidence zone. Carbon dioxide geological sequestration projects require geological structures such as reservoirs and caprocks. Generally, the caving zone and fracture zone can be considered as reservoirs, and the flexural subsidence zone (especially the low-permeability rock strata within it) as the caprock.

[0003] Currently, the technical approaches to carbon dioxide sequestration typically include numerical simulation, theoretical calculation, and physical simulation experiments. However, numerical simulation software generally struggles to accurately characterize the post-mining formation state and fracture distribution. Theoretical calculations simplify the formation, calculating only key parameters of critical strata, which may differ from actual conditions. Physical simulation experiments offer a more intuitive approach, but existing studies primarily focus on the fracturing, migration, subsidence, and fracture development of rock strata caused by mining activities. While some physical simulation experiments involve carbon dioxide sequestration technology, there is a lack of research on carbon dioxide sequestration within the mining space, particularly on the gas migration patterns during the sequestration process. Summary of the Invention

[0004] To address the shortcomings of the existing technology, this invention proposes a physical simulation experimental device for carbon dioxide sequestration in coal mine mining spaces. The device includes a rectangular box shell. Four barrier structures, numbered sequentially from left to right, are arranged within the cavity of the box shell. These four barrier structures divide the cavity into five chambers, also numbered sequentially. A first rubber pad and a cover plate are sequentially arranged on the top surface of the box shell and the barrier structures. Fractured rock mass is placed in the first and second chambers. The first barrier structure is a coal seam plate barrier structure, and the second barrier structure... The third and fourth barrier structures are rock strata barrier structures; the first rubber pad and cover plate at the top surface of the second cavity are equipped with gas injection pipes, which are used to inject carbon dioxide into the second cavity to simulate the process of injecting carbon dioxide into the goaf of a coal mine for sealing; the first cavity is used to simulate adjacent goafs on the plane, the coal seam plate in the first barrier structure is used to simulate the section coal pillar between two goafs, and the second, third and fourth barrier structures are used to simulate the rock strata in the curved and subsided zone above the goaf.

[0005] Preferably, the first rubber pad and the cover plate are fixed to the top surface of the housing and the barrier structure by bolts.

[0006] Preferably, the first and second cavities are the same size, and the third, fourth, and fifth cavities are the same size and their width is smaller than that of the first and second cavities; a number of carbon dioxide pressure sensors are respectively installed in the fractured rock mass of the first and second cavities, and carbon dioxide pressure sensors are installed in the third, fourth, and fifth cavities.

[0007] Preferably, the gas injection pipe is connected in sequence to a gas storage tank, a booster and a pressure gauge, and pressure gauges are also installed on the gas storage tank and the booster; the gas storage tank stores carbon dioxide, and the booster is used to pressurize the carbon dioxide to a set value and inject it into the second chamber.

[0008] Preferably, the front, rear, and bottom plates of the enclosure are provided with grooves for embedding a barrier structure. The barrier structure is centered on a rock stratum plate or coal seam plate, with a second rubber pad layer provided on the left, right, top, and bottom of the rock stratum plate or coal seam plate, but no second rubber pad layer is provided at the center of the left and right sides of the rock stratum plate or coal seam plate. Wing plates and support shoes are provided at the positions where the second rubber pad layer is provided on the left and right sides of the rock stratum plate or coal seam plate, with the support shoes provided at the bottom for embedding in the groove of the bottom plate of the enclosure. Multiple vertical ribs are also provided on the left and right sides of the wing plates, and longitudinal beams are provided between the ribs on the left and right sides above the second rubber pad layer on the top of the rock stratum plate or coal seam plate.

[0009] Preferably, the second rubber pad, wing plate, and rock stratum plate are fixed by bolts and nuts; the second rubber pad, wing plate, and coal seam plate are fixed by bolts and nuts; the wing plate and the support shoe are fixedly connected by welding at adjacent locations.

[0010] Preferably, the ribs are evenly distributed along the front-to-back direction, and ribs are also provided in the grooves in the front and rear side panels of the housing.

[0011] Preferably, several supporting short beams are also provided laterally between the second and third barrier structures, between the third and fourth barrier structures, and between the fourth barrier structure and the right side plate of the housing.

[0012] Preferably, screw holes are provided at corresponding positions on the top surfaces of the cover plate, the first rubber pad, and the four side plates around the box shell, so that the cover plate, the first rubber pad, and the box shell can be connected by bolts; screw holes are provided at corresponding positions on the top surfaces of the cover plate, the first rubber pad, and the longitudinal beam, so that the cover plate, the first rubber pad, and the longitudinal beam can be connected by bolts.

[0013] The method of using the physical simulation experimental device for carbon dioxide sequestration in coal mine mining space according to the present invention includes the following steps: S1: Construct a coal seam plate according to the characteristics of the coal pillar in the actual strata, and construct a rock stratum plate according to the characteristics of the actual bent subsidence zone strata. Use the coal seam plate and rock stratum plate to construct a barrier structure; S2: Fill the first cavity and the second cavity with broken rock mass according to the characteristics of the goaf in the actual strata; install carbon dioxide pressure sensors at the set positions, and pressurize the broken rock mass as needed; S3: Cover with the first rubber pad and the cover plate and fix them with bolts; install the gas injection pipe on the second cavity; S4: Open the gas storage tank, pressurize it to the set pressure through the booster, and then inject carbon dioxide into the second cavity to simulate the sequestration of carbon dioxide in the coal mine goaf; record the values ​​of all carbon dioxide pressure sensors.

[0014] The inventive points and beneficial technical effects of this invention are as follows: The physical simulation experimental device of this invention has several barrier structures arranged sequentially from left to right within a box shell with an upper opening. These barrier structures isolate several cavities. The second cavity is used to simulate a goaf for carbon dioxide sequestration, and the first cavity is used to simulate adjacent goaf areas. The barrier structure between the first and second cavities uses coal seam plates to simulate section coal pillars, while the remaining barrier structures use rock strata plates to simulate the upper curved and subsided zone of the goaf. A first rubber pad and a cover plate are fixed to the upper part of the box shell. This physical simulation experimental device can simultaneously simulate the vertical and horizontal mining spaces in coal mines, as well as the movement of carbon dioxide within these mining spaces during carbon dioxide sequestration. Furthermore, this physical simulation experimental device has strong sealing performance. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the physical simulation experimental device of the present invention.

[0016] Figure 2 This is a schematic diagram of the horizontal cross-section of the cover plate in the physical simulation experimental device of the present invention.

[0017] Figure 3 This is a schematic diagram of the horizontal cross-section of the shell in the physical simulation experimental device of the present invention.

[0018] Figure 4 This is a side view of the barrier structure in the physical simulation experimental device of the present invention (taking the second barrier structure as an example).

[0019] Figure 5 This is a cross-sectional schematic diagram of the front and rear sides of the barrier structure of the present invention (taking the second barrier structure as an example).

[0020] Figure 6 This is a cross-sectional view of the middle part of the barrier structure of the present invention (taking the second barrier structure as an example).

[0021] In the diagram: 1-bolt; 2-longitudinal beam; 3-rib column; 4-rock stratum plate; 5-support shoe; 61-first rubber pad layer; 62-second rubber pad layer; 7-wing plate; 8-air injection pipe; 9-pressure gauge; 10-air storage tank; 11-box shell; 12-cover plate; 13-fractured rock mass; 14-coal seam plate; 15-supporting short beam; 16-booster; 17-carbon dioxide pressure sensor. Detailed Implementation

[0022] The specific embodiments of the present invention will now be described in conjunction with the accompanying drawings.

[0023] like Figures 1-6As shown, this invention proposes a physical simulation experimental device for carbon dioxide sequestration in coal mine mining spaces, comprising a rectangular box shell 11 with an opening at the top forming a cavity; four barrier structures are arranged from left to right within the cavity of the box shell 11, namely a first barrier structure, a second barrier structure, a third barrier structure, and a fourth barrier structure; the four barrier structures divide the cavity of the box shell 11 into five chambers from left to right, namely a first chamber, a second chamber, a third chamber, a fourth chamber, and a fifth chamber. The first and second chambers are the same size, and the third, fourth, and fifth chambers are the same size and width. The degree is less than that of the first and second cavities; a first rubber pad 61 and a cover plate 12 are sequentially arranged on the top surface of the housing 11 and the barrier structure. The first rubber pad 61 and the cover plate 12 are fixed to the top surface of the housing 11 and the barrier structure by bolts 1, so that the cavity of the housing 11 forms a closed cavity, and the first cavity, the second cavity, the third cavity, the fourth cavity and the fifth cavity form five independent closed cavities; a broken rock mass 13 is arranged in the first cavity and the second cavity, and a number of carbon dioxide pressure sensors 17 are respectively arranged in the broken rock mass 13 in the first cavity and the second cavity. Carbon dioxide pressure sensors 17 are installed in the fourth and fifth cavities; the first barrier structure is a coal seam plate 14 barrier structure, and the second, third, and fourth barrier structures are rock strata plate 4 barrier structures; an injection pipe 8 is vertically installed on the first rubber pad 61 and cover plate 12 at the top surface of the second cavity; the injection pipe 8 is used to inject carbon dioxide into the second cavity to simulate the process of injecting carbon dioxide into the goaf of a coal mine for sealing; the first cavity is used to simulate adjacent goafs on the plane, and the coal seam plate 14 in the first barrier structure is used to simulate the section coal pillar between two goafs. The second, third, and fourth barrier structures are used to simulate the rock strata (caprock) in the upper curved subsidence zone of the goaf; that is, the first cavity, the first barrier structure, and the second cavity are used to simulate the horizontal mining space of the goaf where carbon dioxide is sealed, and the second cavity, the second barrier structure, the third barrier structure, and the fourth barrier structure are used to simulate the vertical mining space of the goaf where carbon dioxide is sealed; the purpose of setting up the third cavity, the fourth cavity, and the fifth cavity is to test the pressure of carbon dioxide passing through the second barrier structure, the third barrier structure, and the fourth barrier structure, respectively, and does not represent the actual strata and mining structure.

[0024] like Figure 1 As shown, the gas injection pipe 8 is connected in sequence to a gas storage tank 10, a booster 16, and a pressure gauge 9, and a pressure gauge 9 is also installed on the gas storage tank 10 and the booster 16; the gas storage tank 10 stores carbon dioxide, and the booster 16 is used to pressurize the carbon dioxide to a set value and inject it into the second chamber.

[0025] like Figure 1 , Figures 3-6 As shown, grooves are provided in the front, rear, and bottom plates of the casing 11. These grooves are used to embed barrier structures. The barrier structures are identical, differing only in that the center is either a coal seam plate 14 or a rock stratum plate 4 of different lithologies (the rock stratum plate 4 in the second, third, and fourth barrier structures uses different patterns to represent different lithologies). The barrier structure is centered on the rock stratum plate 4 (or coal seam plate 14). A second rubber pad layer 62 is provided on the left, right, top, and bottom of the rock stratum plate 4 (or coal seam plate 14), but the second rubber pad layer 62 is not provided at the center of the left and right sides of the rock stratum plate 4 (or coal seam plate 14), i.e., the second rubber pad layer 62 is hollowed out in this location (e.g., ...). Figure 4 and Figure 6 As shown, wing plates 7 or support boots 5 are correspondingly installed at the positions where the second rubber pad layer 62 is installed on the left and right sides of the rock stratum plate 4 (or coal seam plate 14). The support boots 5 are installed at the bottom and are embedded in the groove of the bottom plate of the shell 11. The second rubber pad layer 62, wing plates 7 and rock stratum plate 4 (or coal seam plate 14) are fixed by bolts 1 and nuts. The wing plates 7 and support boots 5 are fixedly connected by welding at adjacent positions. In order to improve the lateral deformation resistance and movement capability of the barrier structure, multiple vertical ribs 3 are also provided on the left and right sides of the wing plates 7. The ribs 3 are evenly distributed in the front and rear directions. Preferably, ribs 3 are also provided in the grooves in the front and rear side plates of the shell 11 to prevent the barrier structure from moving in the grooves in the front and rear side plates of the shell 11. In addition, several short support beams 15 are also provided laterally between the second barrier structure and the third barrier structure, between the third barrier structure and the fourth barrier structure, and between the fourth barrier structure and the right side plate of the shell. The shell 11, wing plate 7 and support shoe 5 are all made of steel; on the second rubber pad 62 on the top of the rock stratum plate 4 (or coal seam plate 14), there is a longitudinal beam 2 between the left and right side rib columns 3.

[0026] like Figures 1-2 As shown, screw holes are provided at corresponding positions on the top surfaces of the cover plate 12, the first rubber pad 61, and the four side plates around the box shell 11, so that the cover plate 12, the first rubber pad 61, and the box shell 11 can be connected by bolts 1; screw holes are provided at corresponding positions on the top surfaces of the cover plate 12, the first rubber pad 61, and the longitudinal beam 2, so that the cover plate 12, the first rubber pad 61, and the longitudinal beam 2 can be connected by bolts 1.

[0027] The method of using the physical simulation experimental device for carbon dioxide sequestration in coal mine mining space according to the present invention includes the following steps.

[0028] S1: Based on the characteristics of the coal pillar in the actual strata, coal seam plate 14 is made, and rock stratum plate 4 is made based on the characteristics of the actual bent subsidence zone strata. The coal seam plate 14 and rock stratum plate 4 are used to make a barrier structure.

[0029] S2: Based on the characteristics of the goaf in the actual strata, fractured rock mass 13 is loaded into the first and second cavities; a carbon dioxide pressure sensor 17 is installed at a set position to pressurize the fractured rock mass 13 as needed, and the barrier structure avoids lateral deformation and displacement under the combined action of the wing plate 7, support shoe 5, rib column 3, and support short beam 15.

[0030] S3: Cover the first rubber pad 61 and the cover plate 12 and fix them with bolts 1; install the air injection pipe 8 on the second cavity.

[0031] S4: Open the gas storage tank 10, pressurize it to the set pressure through the booster 16, and inject carbon dioxide into the second chamber to simulate the sealing of carbon dioxide in the goaf of a coal mine; record the values ​​of all carbon dioxide pressure sensors 17; respectively used to simulate and study the characteristics of the goaf (second chamber) where carbon dioxide is sealed, the characteristics of the adjacent goaf (first chamber), the sealing characteristics of the isolation coal pillar (coal bed plate 14) as the cover layer, and the sealing characteristics of the upper curved and subsided zone (rock stratum plate 4) as the cover layer.

[0032] This invention is not limited to the preferred embodiments described above. Anyone can derive other methods in various forms under the guidance of this invention. Any technical solution that is the same as or similar to this application falls within the protection scope of this invention.

Claims

1. A physical simulation experimental device for carbon dioxide sequestration in coal mine mining space, characterized in that, It includes a rectangular box shell, with four barrier structures arranged from left to right and numbered sequentially within the cavity of the box shell. The four barrier structures divide the cavity of the box shell into five chambers from left to right and numbered sequentially. A first rubber pad and a cover plate are arranged sequentially on the top surface of the box shell and the barrier structures. Broken rock mass is arranged in the first chamber and the second chamber. The first barrier structure is a coal seam barrier structure, and the second, third, and fourth barrier structures are rock strata barrier structures. An injection pipe is installed on the first rubber pad and cover plate at the top surface of the second cavity. The injection pipe is used to inject carbon dioxide into the second cavity, simulating the process of injecting carbon dioxide into a coal mine goaf for sealing. The first cavity is used to simulate adjacent goaf areas on a plane. The coal seam in the first barrier structure is used to simulate the coal pillar section between two goaf areas. The second, third, and fourth barrier structures are used to simulate the rock strata in the upper curved subsidence zone of the goaf. The first and second cavities are the same size, and the third, fourth, and fifth cavities are the same size but narrower than the first and second cavities. Several carbon dioxide pressure sensors are installed in the fractured rock mass of the first and second cavities, and carbon dioxide pressure sensors are installed in the third, fourth, and fifth cavities.

2. The physical simulation experimental device for carbon dioxide sequestration in coal mine mining space according to claim 1, characterized in that, The first rubber pad and the cover plate are fixed to the top surface of the housing and the barrier structure by bolts.

3. The physical simulation experimental device for carbon dioxide sequestration in coal mine mining space according to claim 1, characterized in that, The gas injection pipe is connected in sequence to a gas storage tank, a booster, and a pressure gauge, and pressure gauges are also installed on the gas storage tank and the booster. The gas storage tank stores carbon dioxide, and the booster is used to pressurize the carbon dioxide to a set value and inject it into the second chamber.

4. The physical simulation experimental device for carbon dioxide sequestration in coal mine mining space according to claim 3, characterized in that, The front, rear, and bottom plates of the enclosure have grooves for embedding a barrier structure. The barrier structure is centered on a rock stratum plate or coal seam plate, with a second rubber pad layer on the left, right, top, and bottom of the rock stratum plate or coal seam plate, but no second rubber pad layer is provided at the center of the left and right sides of the rock stratum plate or coal seam plate. Wing plates and support shoes are provided at the positions where the second rubber pad layer is provided on the left and right sides of the rock stratum plate or coal seam plate, with the support shoes located at the bottom for embedding in the groove of the bottom plate of the enclosure. Multiple vertical ribs are also provided on the left and right sides of the wing plates, and longitudinal beams are provided between the ribs on the left and right sides above the second rubber pad layer on the top of the rock stratum plate or coal seam plate.

5. The physical simulation experimental device for carbon dioxide sequestration in coal mine mining space according to claim 4, characterized in that, The second rubber pad, wing plate, and rock stratum plate are fixed by bolts and nuts; the second rubber pad, wing plate, and coal seam plate are fixed by bolts and nuts; the wing plate and support shoe are fixedly connected by welding at adjacent locations.

6. The physical simulation experimental device for carbon dioxide sequestration in coal mine mining space according to claim 4, characterized in that, The ribs are evenly distributed along the front-to-back direction, and ribs are also provided in the grooves in the front and rear side panels of the shell.

7. The physical simulation experimental device for carbon dioxide sequestration in coal mine mining space according to claim 4, characterized in that, Several short supporting beams are also provided laterally between the second and third barrier structures, between the third and fourth barrier structures, and between the fourth barrier structure and the right side plate of the box shell.

8. The physical simulation experimental device for carbon dioxide sequestration in coal mine mining space according to claim 1, characterized in that, Screw holes are provided at corresponding positions on the top surfaces of the cover plate, the first rubber pad layer, and the four side plates around the casing; screw holes are also provided at corresponding positions on the top surfaces of the cover plate, the first rubber pad layer, and the longitudinal beams.

9. The method of using the physical simulation experimental device for carbon dioxide sequestration in coal mine mining space as described in claim 8, characterized in that, The process includes the following steps: S1: Construct coal seam plates based on the characteristics of coal pillars in the actual strata, and construct rock strata plates based on the characteristics of the actual bent subsidence zone strata. Use the coal seam plates and rock strata plates to construct a barrier structure; S2: Fill the first and second cavities with fractured rock mass based on the characteristics of the goaf in the actual strata; install carbon dioxide pressure sensors at designated locations and pressurize the fractured rock mass as needed; S3: Cover the first rubber pad and cover plate and secure them with bolts; install an injection pipe on the second cavity; S4: Open the gas storage tank, pressurize it to the set pressure using a booster, and then inject carbon dioxide into the second chamber to simulate the sealing of carbon dioxide in a coal mine goaf; record the values ​​of all carbon dioxide pressure sensors.

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