Device and method for simulating coal seam excavation and goaf water gushing

Abstract

The invention discloses a device and method for simulating coal seam excavation and goaf water gushing, and relates to the technical field of coal mine three-dimensional solid-liquid coupling similar simulation experiments. The device comprises a box body, a rock stratum and a simulated coal seam unit formed by flexible capsule bodies, the surface of the bag body is provided with an easily-melted patch, and the bottom of the bag body is communicated with a water outlet pipe and a flow controller. According to the method, ice blocks in the bag are melted by heating the resistance wire, liquid water is discharged through the flow controller, and sedimentation caused by coal seam excavation is simulated; the temperature is further increased to melt the easily-melted patch, a crevasse is formed in the surface of the capsule body, and water is discharged into the model to simulate goaf gushing water. According to the phase change principle, accurate control over the coal seam excavation speed and the water gushing process is achieved, mechanical disturbance to a model rock stratum is avoided, and the accuracy and repeatability of an experiment are improved.

Description

Technical Field

[0001] This invention relates to the field of three-dimensional solid-liquid coupling similarity simulation experimental technology in coal mines, and in particular to an apparatus and method for simulating coal seam excavation and goaf water inrush. Background Technology

[0002] Three-dimensional similarity simulation experiments are an important means in geotechnical engineering to observe the fracture and collapse patterns of underground rock strata and monitor changes in geostress. Coal seam excavation simulation is a crucial link in ensuring the accuracy of experimental data. Current simulation methods have several limitations: While using hydraulic devices to simulate excavation offers strong controllability, the large size, high cost, and complex operation of hydraulic equipment make it difficult to flexibly arrange within a dense three-dimensional model; manually removing solid pads such as iron plates or wooden boards causes significant mechanical disturbance to the model as a whole, especially the overlying rock strata, resulting in low simulation accuracy; and while pre-embedded solidified paraffin wax and its melting by heating reduces disturbance, the solidification and shaping process of paraffin wax is greatly affected by ambient temperature, often resulting in uneven melting that is difficult to control, making it impossible to accurately simulate the excavation process or obtain reliable experimental data. Therefore, there is an urgent need for an experimental device and method that can avoid mechanical disturbance while precisely controlling the excavation process and simulating special conditions such as water inrush. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and to provide an apparatus and method for simulating coal seam excavation and goaf water inrush. By filling a non-insulating flexible bladder with ice and setting a conductive heating wire, the phase change principle is used in conjunction with a flow control device to accurately simulate coal seam excavation settlement. Furthermore, by heating and melting the fusible patch, the fluid-structure interaction simulation of goaf water inrush is achieved.

[0004] In a first aspect, the present invention provides an apparatus for simulating coal seam excavation and goaf water inrush, comprising:

[0005] The box is a hollow structure with an open top, used to house the experimental model;

[0006] The bottom rock layer is laid on the inner bottom surface of the box body;

[0007] A simulated coal seam unit is laid on top of the underlying rock strata to simulate the coal seam structure;

[0008] Overlying rock strata are laid above and around the simulated coal seam unit;

[0009] The simulated coal seam unit includes a flexible capsule, a conductive heating wire disposed inside the flexible capsule partition, a fusible patch disposed on the wall of the flexible capsule, and a water outlet pipe communicating with the interior of the flexible capsule.

[0010] The flexible capsule is used to fill solid ice, and one end of the water outlet extends to the outside of the box to discharge the liquid water after the ice melts in the flexible capsule.

[0011] The fusible patch is made of thermoplastic material and is used to melt and rupture at a specific temperature to form a rupture connecting the interior of the flexible bladder to the interior of the box.

[0012] The device further includes a temperature sensor, a flow sensor, a temperature controller, and a flow controller; the temperature sensor is disposed on the surface of the flexible bladder, the flow sensor is disposed inside the water outlet pipe, the conductive heating wire is electrically connected to the temperature controller via a wire, and the flow controller is connected to the water outlet pipe to control the drainage rate.

[0013] Furthermore, the flexible capsule is rectangular in shape, its capsule wall is a hollow double-layer structure, and the inner and outer surfaces of the flexible capsule are made of non-insulating material with thermal conductivity; the conductive heating wire is evenly distributed in the internal space of the flexible capsule.

[0014] Furthermore, there are multiple fusible patches, which are respectively disposed on the bottom and side surfaces of the flexible capsule. The fusible patches are made of EVA or polyolefin material, with a melting point higher than that of ice and lower than that of the flexible capsule body material, and are used to undergo phase change melting when the conductive heating wire is continuously heated to a set threshold.

[0015] Furthermore, the water outlet pipe is located at the bottom of the flexible bladder, and the wire extends from the bottom of the flexible bladder; the flow controller and the temperature controller are located outside the housing, the flow controller is connected to the flow sensor via a wire, and the temperature controller is connected to the temperature sensor and the conductive heating wire via a wire.

[0016] Furthermore, the housing is made of a transparent rigid material, and the bottom of the housing has a reserved hole for the water outlet pipe and the wire to pass through; the device also includes a water storage tank, which is located at the outlet end of the water outlet pipe and is used to collect the discharged liquid water.

[0017] Secondly, the present invention also provides a method for using the apparatus described above to simulate coal seam excavation and goaf water inrush, comprising the following steps:

[0018] Step S1: Lay a similar simulated material at the bottom of the box to construct the bottom rock layer;

[0019] Step S2: Fill the flexible capsule with ice and lay the flexible capsule containing ice on the bottom rock layer according to the predetermined coal seam distribution shape, as the simulated coal seam unit.

[0020] Step S3: Lay similar simulated materials above and around the simulated coal seam unit to construct the overlying rock layer, and wait for the model to dry and solidify;

[0021] Step S4: Simulate coal seam excavation. The temperature controller controls the conductive heating wire to generate electricity and heat up, melting the ice in the flexible capsule into liquid water. The flow controller controls the outlet pipe to discharge the liquid water out of the capsule. The shrinkage of the capsule volume simulates coal seam excavation and roof collapse.

[0022] Step S5: Simulate water inrush in the goaf. After the ice in the flexible capsule melts, the heating temperature of the conductive heating wire is further increased by the temperature controller until the fusible patch melts, forming a rupture on the surface of the flexible capsule, allowing the remaining liquid water in the flexible capsule to drain into the internal model of the box.

[0023] Further, in step S2, the simulated coal seam units are arranged according to the predetermined excavation mode; if simulating whole-area mining, a single large-sized flexible capsule or multiple closely arranged small-sized flexible capsules are laid; if simulating strip mining or room-and-pillar mining, multiple flexible capsules are laid at intervals, and the water outlet pipes of adjacent flexible capsules are not connected to each other and extend to the outside of the box body respectively.

[0024] Furthermore, in step S4, the heating sequence of the multiple simulated coal seam units is adjusted according to the mining process; if segmented mining is simulated, the conductive heating wires in the flexible capsules at different locations are controlled sequentially by the temperature controller, and the corresponding flow controllers are opened sequentially to realize the melting of ice and drainage in different areas.

[0025] Furthermore, in step S5, the specific melting temperature of the fusible patch is set to 30°C; when the temperature sensor detects that the temperature of the conductive heating wire reaches this specific temperature, the fusible patch automatically melts to form an irreparable break, simulating the formation process of a water inrush channel in the floor or sidewall of a goaf.

[0026] Furthermore, in steps S1 and S3, the similarity simulation material is a mixture of quartz sand, cement, water and dimethyl silicone oil, and its proportion is determined according to the similarity principle and the physical and mechanical properties of the actual rock strata; in step S4, the drainage rate is monitored in real time by the flow sensor, and the opening of the drainage valve is adjusted by the flow controller to match the coal seam mining speed in the actual project.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) This invention uses a flexible capsule structure containing conductive heating resistance wire, temperature sensor and flow control system to replace the traditional mechanical pulling or hydraulic contraction by using the physical phase change process of ice melting into water and being discharged through the pipe. This not only eliminates the mechanical disturbance to the overlying rock layer when the traditional solid pad is pulled out, ensuring the integrity of the model structure, but also allows for precise adjustment of the drainage rate with the flow controller, thereby achieving precise control of the coal seam excavation speed and significantly improving the accuracy of the experimental simulation.

[0029] (2) The present invention uses flexible capsules as coal seam simulation units. By changing the size and number of flexible capsules and adjusting the laying method on the bottom rock layer to whole area laying, intermittent laying, etc., the device can flexibly simulate a variety of complex coal mining processes, including whole area mining, segmented strip mining and room and pillar mining. At the same time, the thickness of the coal seam and the surface undulation distribution can be controlled by the shape of the capsules, which solves the problem that existing rigid devices are difficult to adapt to complex coal seam geological conditions.

[0030] (3) The present invention sets a fusible patch made of thermoplastic material on the surface of the flexible capsule. By controlling the conductive heating wire to reach a specific high temperature threshold, the patch melts and breaks. Without destroying the overall structure of the model, a controllable opening can be formed on the surface of the capsule, and the liquid water in the capsule can be directly released into the model. This can realistically simulate fluid-structure interaction phenomena such as water inrush in goaf areas, filling the gap that traditional solid or simple paraffin models cannot effectively simulate water inrush conditions.

[0031] (4) The present invention constructs an overall control system including a temperature sensor, a temperature controller, a flow sensor and a flow controller. The capsule embedded in the model is connected to the external control terminal through wires. All key indicators such as temperature change, melting rate and drainage during coal seam excavation are parameterized and visualized, so that the experimental process can be accurately repeated, the experimental data is more accurate and reliable, and the melted water can be recycled, reducing the experimental cost. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the simulated coal seam excavation and goaf water inrush device of the present invention;

[0033] Figure 2 This is a schematic diagram of the structure of the simulated coal seam unit and its external control system connection according to the present invention;

[0034] Figure 3 This is a schematic diagram of the mining modes that can be simulated by the present invention, wherein (a) is whole-area mining, (b) is segmented mining / strip mining, (c) is room-and-pillar mining, and (d) is the height of coal seam surface undulation.

[0035] Figure 4 This is a flowchart illustrating the method of the present invention;

[0036] Reference numerals: 1. Box body; 2. Simulated coal seam unit; 3. Overlying strata; 4. Bottom strata; 5. Flexible capsule; 6. Fusible patch; 7. Water outlet pipe; 8. Flow sensor; 9. Flow controller; 10. Temperature sensor; 11. Temperature controller; 12. Wire; 13. Non-insulating material; 14. Conductive heating wire; 15. Water storage tank. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0038] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0039] In the description of the invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0040] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] Example 1

[0042] like Figure 1 and Figure 2As shown, this embodiment provides a device for simulating coal seam excavation and goaf water inrush. The box 1 is a hollow structure with an open top, used to house the experimental model. The box 1 is made of a transparent, rigid material, allowing observation of the internal rock strata collapse and movement process during the experiment. The bottom of the box 1 has pre-drilled holes for the water supply pipe 7 and the wire 12 to pass through. The bottom rock stratum 4 is laid on the inner bottom surface of the box 1, the simulated coal seam unit 2 is laid above the bottom rock stratum 4, and the overlying rock stratum 3 is laid above and around the simulated coal seam unit 2. The bottom rock stratum 4 and the overlying rock stratum 3 are composed of a mixture of similar simulated materials such as quartz sand, cement, water, and dimethyl silicone oil, and their physical and mechanical properties correspond to the physical and mechanical properties of actual strata according to the principle of similarity.

[0043] The simulated coal seam unit 2 is the core component of this invention, comprising a flexible capsule 5, conductive heating wires 14 disposed inside the flexible capsule 5, easily fusible patches 6 disposed on the wall of the flexible capsule 5, and a water outlet pipe 7 connecting the interior of the flexible capsule 5. The flexible capsule 5 is generally rectangular in shape, with a hollow double-layered wall. The inner and outer surfaces of the flexible capsule 5 are made of a non-insulating material 13, which has thermal conductivity and is characterized by easy heat and cold conduction. The conductive heating wires 14 are evenly distributed within the interior space of the flexible capsule 5 to heat and melt the ice inside the capsule. The interior of the flexible capsule 5 is filled with solid ice, which supports the shape of the capsule and simulates the coal seam structure.

[0044] Multiple fusible patches 6 are disposed on the bottom and sides of the flexible capsule 5. Each flexible capsule 5 may contain 5 fusible patches 6. The fusible patches 6 are made of EVA or polyolefin material, with a melting point higher than that of ice but lower than that of the flexible capsule 5 body material. The fusible patches 6 can automatically melt at a specific temperature, forming one or more controllable openings on the surface of the flexible capsule 5, allowing the liquid water inside the flexible capsule 5 to drain into the goaf, thereby simulating goaf water inrush.

[0045] The water outlet pipe 7 is located at the bottom of the flexible bladder 5, with one end extending to the outside of the housing 1, and is used to drain the liquid water after the ice melts inside the flexible bladder 5. The wire 12 extends from the bottom of the flexible bladder 5 and is used to connect the power supply, the conductive heating wire 14 inside the flexible bladder 5, the temperature sensor 10, and various control devices.

[0046] like Figure 2As shown, the device also includes a temperature sensor 10, a flow sensor 8, a temperature controller 11, and a flow controller 9. The temperature sensor 10 is disposed on the surface of the flexible capsule 5 and is used to monitor the temperature of the conductive heating wire 14. The flow sensor 8 is disposed inside the water outlet pipe 7 and is used to monitor the drainage rate of the capsule. The flow controller 9 and the temperature controller 11 are disposed outside the housing 1. The flow controller 9 is connected to the flow sensor 8 via a wire, and the temperature controller 11 is connected to the temperature sensor 10 and the conductive heating wire 14 via a wire. The conductive heating wire 14 is electrically connected to the temperature controller 11 via a wire 12, and the flow controller 9 is connected to the water outlet pipe 7 to control the drainage rate. Through the coordinated operation of the temperature controller 11 and the flow controller 9, the speed of coal seam excavation and the process of water inflow in the goaf can be precisely controlled.

[0047] The device also includes a water storage tank 15, which is located at the outlet end of the water outlet pipe 7 and is used to collect the discharged liquid water. After the solid ice inside the flexible capsule 5 melts, it enters the water storage tank 15, and the water can be re-injected into the flexible capsule 5 for reuse. This method is low-cost and simple to operate.

[0048] Example 2

[0049] like Figure 3 As shown, by changing the size, number, and laying method of the flexible capsules 5 on the bottom rock layer 4, the device of the present invention can flexibly simulate a variety of complex coal mining processes. For example, when simulating whole-area mining... Figure 3 As shown in diagram a, a single large flexible capsule 5 or multiple closely arranged small flexible capsules 5 are used for laying, or a specific number of small flexible capsules 5 are laid evenly. If simulating strip mining or room-and-pillar mining, such as... Figure 3 b and Figure 3 As shown in diagram c, multiple flexible capsules 5 are laid at intervals. A specific number of flexible capsules 5 are laid evenly or regularly in sections above the bottom rock layer 4, and the water outlet pipes 7 of adjacent flexible capsules 5 are not connected to each other and extend to the outside of the box 1 respectively. If simulating segmented mining or other localized mining, a specific number of flexible capsules 5 are laid in sections. For example... Figure 3 As shown in d, by changing the shape of the flexible capsule 5, the thickness of the coal seam and the distribution of surface undulations can also be controlled to simulate the height of surface undulations of the coal seam.

[0050] Example 3

[0051] like Figure 4As shown, this embodiment provides a method for simulating coal seam excavation and goaf water inrush. Based on the actual engineering geological conditions of the coal mine and the physical and mechanical properties of the bottom rock stratum 4, similar simulation materials are laid at the bottom of the box 1 to construct the bottom rock stratum 4. Similar simulation materials such as quartz sand, kaolin, water, cement, and dimethyl silicone oil are used, and their proportions are determined according to the similarity principle and the physical and mechanical properties of the actual rock strata. The materials are laid in accordance with the similarity principle.

[0052] Ice blocks of a specific shape are placed into flexible capsules 5, and these capsules 5, filled with ice, are laid on top of the floor strata 4 according to a predetermined coal seam distribution pattern, serving as simulated coal seam units 2. Based on the actual engineering geological conditions of the coal seam and the predetermined excavation mode, a specific number of flexible capsules 5 are laid on top of the floor strata 4 to simulate the coal seam. If simulating whole-area mining, a single large flexible capsule 5 or multiple closely arranged small flexible capsules 5 are used. If simulating strip mining or room-and-pillar mining, multiple flexible capsules 5 are laid at intervals; in this case, the water outlet pipes 7 of two adjacent flexible capsules 5 are not connected to each other, but extend separately to the outside of the housing 1. If simulating segmented mining or other localized mining, a specific number of flexible capsules 5 are laid evenly or regularly in designated areas.

[0053] Based on the actual engineering geological conditions of the coal mine and the physical and mechanical properties of the overlying stratum 3, similar simulation materials were laid above and around the simulated coal seam unit 2 to construct the overlying stratum 3. The laying was carried out in accordance with the principle of similarity, and the model was allowed to dry and solidify. The drying time depended on the laboratory temperature and the similarity ratio of the materials.

[0054] After the model dries, coal seam excavation is simulated based on the actual coal mining process or the purpose of a three-dimensional similarity simulation experiment. The temperature controller 11 controls the conductive heating wire 14 to generate heat, melting the ice inside the flexible capsule 5 into liquid water. The flow controller 9 controls the outlet pipe 7 to discharge the liquid water out of the capsule 1. The shrinkage of the capsule volume simulates coal seam excavation and roof collapse. The flow sensor 8 monitors the drainage rate in real time, and the flow controller 9 adjusts the opening of the drainage valve to match the actual coal seam mining speed in engineering.

[0055] The heating sequence of multiple simulated coal seam units 2 is adjusted according to the mining process. If simulating whole-area mining, the temperature controller 11 simultaneously heats the conductive heating wires 14 inside all flexible capsules 5, melting all ice blocks inside the flexible capsules 5 and draining all liquid water from the housing 1. If simulating normal mining, the temperature controller 11 sequentially melts the ice blocks inside the flexible capsules 5 and drains all liquid water from the housing 1. If simulating segmented mining, the temperature controller 11 sequentially controls the conductive heating wires 14 inside the flexible capsules 5 at different locations, and sequentially opens the corresponding flow controllers 9 to achieve ice melting and drainage in different areas. If simulating strip mining, the temperature controller 11 sequentially and intermittently melts the ice blocks inside the flexible capsules 5 and drains all liquid water from the housing 1. If simulating room-and-pillar mining, the temperature controller 11 distributes the melting of ice blocks inside the flexible capsules 5 and drains all liquid water from the housing 1.

[0056] If simulating backfilling mining, the ice inside the flexible capsule 5 is melted by the temperature controller 11, allowing some of the liquid water to drain out of the box 1, while the rest remains inside the model. If simulating goaf water inrush, after the ice inside the flexible capsule 5 melts, the heating temperature of the conductive heating wire 14 is further increased by the temperature controller 11, thereby melting the fusible patch 6 and creating a controllable opening in the flexible capsule 5, until the fusible patch 6 melts, forming an opening on the surface of the flexible capsule 5. This allows the remaining liquid water inside the flexible capsule 5 to drain into the model inside the box 1, simulating goaf water inrush, and then proceeding to the next fluid-structure interaction similarity simulation experiment.

[0057] The specific melting temperature of the fusible patch 6 is set to 30℃. When the temperature sensor 10 detects that the temperature of the conductive heating wire 14 reaches this specific temperature, the fusible patch 6 automatically melts to form an irreparable breach, simulating the formation process of a water inrush channel in the floor or sidewall of a goaf. Through the coordinated use of the temperature sensor 10, temperature controller 11, flow sensor 8, and flow controller 9, all control conditions can be parameterized, resulting in more accurate and reliable results. After the experiment, the flexible capsule 5 can be reused, reducing experimental costs.

[0058] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0059] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A device for simulating coal seam excavation and goaf water inrush, characterized in that, include: Box (1), the box (1) is a hollow structure with an open top, used to accommodate the experimental model; The bottom rock layer (4) is laid on the inner bottom surface of the box body (1); The simulated coal seam unit (2) is laid on top of the bottom rock layer (4) to simulate the coal seam structure; The overlying rock layer (3) is laid above and around the simulated coal seam unit (2); The simulated coal seam unit (2) includes a flexible capsule (5), a conductive heating wire (14) disposed inside the flexible capsule (5), a fusible patch (6) disposed on the wall of the flexible capsule (5), and a water outlet pipe (7) connecting the inside of the flexible capsule (5). The flexible capsule (5) is used to fill solid ice, and one end of the water outlet pipe (7) extends to the outside of the box (1) to discharge the liquid water after the ice melts in the flexible capsule (5). The fusible patch (6) is made of thermoplastic material and is used to melt and rupture at a specific temperature to form a rupture that connects the interior of the flexible bladder (5) with the interior of the box (1); The device also includes a temperature sensor (10), a flow sensor (8), a temperature controller (11), and a flow controller (9); the temperature sensor (10) is disposed on the surface of the flexible bladder (5), the flow sensor (8) is disposed inside the water outlet pipe (7), the conductive heating wire (14) is electrically connected to the temperature controller (11) through a wire (12), and the flow controller (9) is connected to the water outlet pipe (7) to control the drainage rate.

2. The apparatus for simulating coal seam excavation and goaf water inrush according to claim 1, characterized in that, The flexible capsule (5) is rectangular in shape, and its capsule wall is a hollow double-layer structure. The inner and outer surfaces of the flexible capsule (5) are made of non-insulating material (13), which has thermal conductivity. The conductive heating wire (14) is evenly distributed in the internal space of the flexible capsule (5).

3. The apparatus for simulating coal seam excavation and goaf water inrush according to claim 1, characterized in that, The number of the fusible patches (6) is multiple, and they are respectively disposed on the bottom and side surfaces of the flexible capsule (5). The material of the fusible patches (6) is EVA or polyolefin material, which has a melting point higher than that of ice and lower than that of the body material of the flexible capsule (5), and is used to undergo phase change melting when the conductive heating wire (14) is continuously heated to a set threshold.

4. The apparatus for simulating coal seam excavation and goaf water inrush according to claim 1, characterized in that, The water outlet pipe (7) is located at the bottom of the flexible bladder (5), and the wire (12) is led out from the bottom of the flexible bladder (5); the flow controller (9) and the temperature controller (11) are located outside the housing (1), the flow controller (9) is connected to the flow sensor (8) through the wire, and the temperature controller (11) is connected to the temperature sensor (10) and the conductive heating wire (14) through the wire.

5. The apparatus for simulating coal seam excavation and goaf water inrush according to claim 1, characterized in that, The box (1) is made of transparent hard material. The bottom of the box (1) has a reserved hole for the water outlet pipe (7) and the wire (12) to pass through. The device also includes a water storage tank (15), which is located at the outlet end of the water outlet pipe (7) and is used to collect the discharged liquid water.

6. A method using the apparatus for simulating coal seam excavation and goaf water inrush as described in claim 1, characterized in that, Includes the following steps: Step S1: Lay similar simulated material at the bottom of the box (1) to construct the bottom rock layer (4). Step S2: Fill the flexible capsule (5) with ice and lay the flexible capsule (5) filled with ice on top of the bottom rock layer (4) according to the predetermined coal seam distribution shape, as the simulated coal seam unit (2). Step S3: Lay similar simulated materials above and around the simulated coal seam unit (2) to construct the overlying rock layer (3), and wait for the model to dry and solidify; Step S4: Perform coal seam excavation simulation. The temperature controller (11) controls the conductive heating wire (14) to be energized and heated to melt the ice in the flexible capsule (5) into liquid water. The flow controller (9) controls the water outlet pipe (7) to discharge the liquid water out of the box (1). The volume shrinkage of the capsule simulates coal seam excavation and roof collapse. Step S5: Simulate water inrush in the goaf. After the ice in the flexible capsule (5) melts, the heating temperature of the conductive heating wire (14) is further increased by the temperature controller (11) until the fusible patch (6) melts and a hole is formed on the surface of the flexible capsule (5), so that the remaining liquid water in the flexible capsule (5) is drained into the internal model of the box (1).

7. The method according to claim 6, characterized in that, In step S2, the simulated coal seam unit (2) is arranged according to the predetermined excavation mode; if the whole area mining is simulated, a single large-sized flexible capsule (5) or a number of closely arranged small-sized flexible capsules (5) are laid; if strip mining or room-and-pillar mining is simulated, multiple flexible capsules (5) are laid at intervals, and the water outlet pipes (7) of adjacent flexible capsules (5) are not connected to each other and extend to the outside of the box (1).

8. The method according to claim 6, characterized in that, In step S4, the heating sequence of multiple simulated coal seam units (2) is adjusted according to the mining process; if the simulated segmented mining is carried out, the conductive heating wires (14) in the flexible capsules (5) at different positions are controlled in sequence by the temperature controller (11), and the corresponding flow controllers (9) are turned on in sequence to realize the melting of ice blocks and drainage in different areas.

9. The method according to claim 6, characterized in that, In step S5, the specific melting temperature of the fusible patch (6) is set to 30°C. When the temperature sensor (10) detects that the temperature of the conductive heating wire (14) reaches the specific temperature, the fusible patch (6) automatically melts to form an irreparable break, simulating the formation process of water inrush channels in the bottom plate or side wall of the goaf.

10. The method according to claim 6, characterized in that, In steps S1 and S3, the similar simulation material is a mixture of quartz sand, cement, water and dimethyl silicone oil, and its proportion is determined according to the similarity principle and the physical and mechanical properties of the actual rock strata. In step S4, the drainage rate is monitored in real time by the flow sensor (8), and the opening of the drainage valve is adjusted by the flow controller (9) to match the coal seam mining speed in the actual project.

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