Coal mining three-dimensional physical similar simulation experiment device

Abstract

The invention provides a coal mining three-dimensional physical similar simulation experiment device. The coal mining three-dimensional physical similar simulation experiment device comprises a box body; the stratum simulation body comprises an upper-layer simulation body and a lower-layer simulation body, and the upper-layer simulation body and the lower-layer simulation body are arranged in a spaced and layered mode in the height direction; the water bag is arranged between the upper-layer simulation body and the lower-layer simulation body, the water bag is provided with a liquid storage cavity, a liquid inlet and a liquid outlet, and the liquid inlet and the liquid outlet are both communicated with the liquid storage cavity; the temperature control structure is arranged on the water bag, and the temperature control structure can control the temperature of the liquid in the liquid storage cavity so as to solidify or melt the liquid in the liquid storage cavity; water seepage holes are further formed in the upper wall and the lower wall of the water bag and communicated with the liquid storage cavity, and the water bag can drain water into the box body through the water seepage holes. According to the technical scheme, coal seam excavation behaviors under various working conditions can be simulated, and the problem that in the prior art, an experimental device cannot effectively simulate goaf water gushing in the coal mining process can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of coal mining, in particular to a three-dimensional physical similarity simulation experimental device for coal mining. Background Art

[0002] Three-dimensional similarity simulation experiment is one of the commonly used technical means in the field of geotechnical engineering. It can be used to observe the fracture and collapse laws of underground rock formations and monitor the characteristics of ground stress changes at various stages. The specific implementation process of the three-dimensional similarity simulation experiment is to simulate and build structures such as actual strata, rock formations and soil layers using similar simulation materials based on the project site conditions, and then simulate excavation according to the actual mining process after drying, and record the relevant parameters during the excavation process.

[0003] For the field of coal mining engineering, coal seam excavation simulation is the key to the entire three-dimensional similarity simulation experiment, which is related to the accuracy and reliability of experimental data. At present, there are some methods, all of which simulate the coal seam by setting fillers in the three-dimensional model, such as solid pads, solidified paraffin or hydraulic oil bags, and gradually reduce the volume of the simulated coal seam to simulate the excavation process, so as to record and observe the impact of coal seam changes on the stratum during the excavation process. However, in the actual coal mining process, with the advancement of the comprehensive mining face, the goaf is very likely to have water gushing, which has a great impact on the actual stratum and mining face. The simulation experimental device in the prior art cannot effectively simulate the impact of water gushing in the goaf during coal mining. Summary of the invention

[0004] The invention provides a three-dimensional physical similarity simulation experimental device for coal mining, so as to solve the problem that the experimental device in the prior art cannot effectively simulate water gushing in the goaf during coal mining.

[0005] The invention provides a three-dimensional physical similarity simulation experimental device for coal mining, which comprises: a box body; a stratum simulation body, which is arranged in the box body, and the stratum simulation body comprises an upper simulation body and a lower simulation body, and the upper simulation body and the lower simulation body are arranged in layers at intervals along the height direction; a water bag, which is arranged between the upper simulation body and the lower simulation body, and the water bag has a liquid storage cavity, a liquid inlet and a liquid outlet, and the liquid inlet and the liquid outlet are both connected with the liquid storage cavity, and the water bag is connected with the outside of the box body through the liquid inlet and the liquid outlet; a temperature control structure, which is arranged on the water bag, and the temperature control structure can reduce the temperature of the liquid in the liquid storage cavity to solidify the liquid in the liquid storage cavity, or increase the temperature of the liquid in the liquid storage cavity to melt the liquid in the liquid storage cavity; wherein, a water seepage hole is also arranged on the side wall of the water bag, and the water seepage hole is connected with the liquid storage cavity, and a plugging piece is arranged on the water bag, and the plugging piece opens or blocks the water seepage hole, and the water bag can drain water into the box body through the water seepage hole.

[0006] Furthermore, the side wall of the water bag has an inner layer and an outer layer that are spaced apart, and a hollow layer is formed between the inner layer and the outer layer. The hollow layer forms a temperature control structure. A feed port and a discharge port are provided on the side wall of the water bag. Both the feed port and the discharge port are connected to the hollow layer. The hollow layer is used to pass a refrigerant to control the temperature of the water bag.

[0007] Furthermore, a liquid inlet pipe is provided at the liquid inlet, a liquid outlet pipe is provided at the liquid outlet, and a first flow control valve and a flow detection component are provided on both the liquid inlet pipe and the liquid outlet pipe.

[0008] Furthermore, a feed pipe is provided at the feed port, a discharge pipe is provided at the discharge port, and both the feed pipe and the discharge pipe are provided with a second flow control valve and a temperature detection component.

[0009] Furthermore, a plurality of water seepage holes are provided, and water seepage holes are provided on the surfaces of the water bag close to the upper simulation body and the lower simulation body.

[0010] Furthermore, a plurality of water bags are provided, and the plurality of water bag arrays are arranged between the upper simulation body and the lower simulation body.

[0011] Furthermore, the multiple water bags include multiple first simulation groups and multiple second simulation groups, the first simulation groups and the second simulation groups are alternately distributed in sequence along the width direction, the hollow layers of the water bags of the multiple first simulation groups are connected, and the liquid storage cavities of the water bags of the multiple first simulation groups are connected.

[0012] Furthermore, the hollow layers of two adjacent water bags are connected, and the liquid storage cavities of two adjacent water bags are connected.

[0013] Furthermore, the hollow layers of two adjacent water bags are not connected, and the liquid storage cavities of two adjacent water bags are not connected.

[0014] Furthermore, ice cubes are arranged in the liquid storage chamber, and the ice cubes are used to simulate coal seams at different heights.

[0015] The technical solution of the present invention is applied. By arranging a water bag between the upper simulation body and the lower simulation body, when the water in the liquid storage chamber of the water bag freezes under the adjustment of the temperature control structure, the water bag as a whole changes into a hard solid structure. The water bag can simulate the state of the coal seam between the upper simulation body and the lower simulation body. When it is necessary to simulate coal seam excavation, the temperature of the ice in the liquid storage chamber of the water bag can be increased by the temperature control structure to melt the ice, so as to simulate the process of gradual mining of the coal seam and observe the address change during the coal mining process. After the water in the liquid storage chamber solidifies and freezes, the seepage hole can be opened by the plugging member. In this way, when the ice melts, the water in the liquid storage chamber can penetrate into the upper simulation body and the lower simulation body through the seepage hole to simulate the water gushing in the goaf. The present application can simultaneously meet the scenes of simulating coal mining and water gushing in the goaf through the water bag and the temperature control structure, so that the three-dimensional physical similarity simulation test device of real coal mining can adapt to a wider range of application scenarios, improve the use effect of the experimental device, and can carry out fluid-solid coupling similarity simulation research on the stability of coal pillar dams in water-rich environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 The schematic diagram of the structure of the three-dimensional physical similarity simulation experimental device for coal mining provided by the present invention is shown;

[0018] Figure 2 The schematic diagram of the structure of the water bag provided by the present invention is shown;

[0019] Figure 3 It shows a schematic structural diagram of the water bag arrangement in the first embodiment provided by the present invention;

[0020] Figure 4 It shows a schematic structural diagram of the water bag arrangement in the second embodiment provided by the present invention;

[0021] Figure 5 It shows a schematic structural diagram of the water bag arrangement in the third embodiment provided by the present invention;

[0022] Figure 6 It shows a schematic structural diagram of the water bag arrangement in the fourth embodiment provided by the present invention;

[0023] Figure 7 It shows a schematic structural diagram of a water bag arrangement in a fifth embodiment provided by the present invention;

[0024] Figure 8 A schematic structural diagram of ice cubes arranged in a water bag provided by the present invention is shown.

[0025] The above drawings include the following reference numerals:

[0026] 100, box body;

[0027] 210, upper simulation body; 220, lower simulation body;

[0028] 300, water bladder;

[0029] 310. Water seepage hole;

[0030] 321, liquid inlet pipe; 322, liquid outlet pipe; 323, first flow control valve; 324, flow detection element;

[0031] 331. Feed pipe; 332. Discharge pipe; 333. Second flow control valve; 334. Temperature detection element. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] like Figure 1 As shown, an embodiment of the present invention provides a three-dimensional physical similarity simulation experimental device for coal mining, which includes a box 100, a formation simulation body, a water bag 300 and a temperature control structure. Among them, the formation simulation body is arranged in the box 100, and the formation simulation body includes an upper simulation body 210 and a lower simulation body 220, and the upper simulation body 210 and the lower simulation body 220 are arranged in layers at intervals along the height direction. The water bag 300 is arranged between the upper simulation body 210 and the lower simulation body 220, and the water bag 300 has a liquid storage cavity, a liquid inlet and a liquid outlet, and the liquid inlet and the liquid outlet are both connected to the liquid storage cavity, and the water bag 300 is connected to the outside of the box 100 through the liquid inlet and the liquid outlet. The temperature control structure is arranged on the water bag 300, and the temperature control structure can reduce the temperature of the liquid in the liquid storage cavity to solidify the liquid in the liquid storage cavity, or increase the temperature of the liquid in the liquid storage cavity to melt the liquid in the liquid storage cavity. A water seepage hole 310 is also provided on the side wall of the water bag 300 , and the water seepage hole 310 is connected to the liquid storage chamber. A blocking piece is provided on the water bag 300 , and the blocking piece opens or blocks the water seepage hole 310 , and the water bag 300 can drain water into the box body 100 through the water seepage hole 310 .

[0034] By applying the technical solution of the present invention, a water bag 300 is arranged between the upper simulation body 210 and the lower simulation body 220. When the water in the liquid storage chamber of the water bag 300 freezes under the adjustment of the temperature control structure, the water bag 300 as a whole changes into a hard solid structure. The water bag 300 can simulate the state of the coal seam between the upper simulation body 210 and the lower simulation body 220. When it is necessary to simulate coal seam excavation, the temperature of the ice in the liquid storage chamber of the water bag 300 can be increased by the temperature control structure to melt the ice, so as to simulate the process of gradual mining of the coal seam and observe the address change during the coal mining process. After the water in the liquid storage chamber solidifies and freezes, the water seepage hole 310 can be opened by the plugging member. In this way, when the ice melts, the water in the liquid storage chamber can penetrate into the space between the upper simulation body 210 and the lower simulation body 220 through the water seepage hole 310 to simulate the water gushing in the goaf. The present application can simultaneously simulate the scenarios of coal mining and water gushing in goaf areas through the water bag 300 and the temperature control structure, so that the three-dimensional physical similarity simulation test device of real coal mining can adapt to a wider range of application scenarios, improve the use effect of the experimental device, and can carry out fluid-solid coupling similarity simulation research on aspects such as the stability of coal pillar dams in water-rich environments.

[0035] In a specific embodiment of the present application, the side wall of the water bag 300 has an inner layer and an outer layer arranged at intervals, a hollow layer is formed between the inner layer and the outer layer, and the hollow layer forms a temperature control structure. A feed port and a discharge port are arranged on the side wall of the water bag 300, and both the feed port and the discharge port are connected to the hollow layer, and the hollow layer is used to pass a refrigerant to control the temperature of the water bag 300. Through the above arrangement, the refrigerant in the hollow layer can exchange heat with the water in the accommodating cavity through the inner layer to adjust the temperature in the liquid storage cavity. When it is necessary to reduce the internal temperature of the water bag 300, a refrigerant such as nitrogen or liquid nitrogen can be passed into the hollow layer through the feed port; when it is necessary to increase the internal temperature of the water bag 300, hot water can be passed into the hollow layer through the feed port.

[0036] In other embodiments of the present application, the surface of the water bag 300 may also be covered with an electric heating device or a cooling device to adjust the temperature inside the water bag 300 .

[0037] Specifically in the present application, a liquid inlet is provided at the liquid inlet, a liquid outlet is provided at the liquid outlet, and a first flow control valve 323 and a flow detection member 324 are provided on the liquid inlet 321 and the liquid outlet 322. By providing the first flow control valve 323 and the flow detection member 324, the flow rate of the fluid flowing into or out of the liquid storage cavity can be controlled, which is convenient for accurate adjustment of the coal seam simulation excavation experiment and improves the accuracy of the simulation experiment.

[0038] Specifically in the present application, a feed pipe 331 is provided at the feed port, a discharge pipe 332 is provided at the discharge port, and a second flow control valve 333 and a temperature detection member 334 are provided on both the feed pipe 331 and the discharge pipe 332. By providing the second flow control valve 333 and the temperature detection member 334, the flow rate of the refrigerant flowing in or out of the hollow layer can be controlled, so as to accurately adjust the temperature of the water stored in the water bag and improve the accuracy of the simulation experiment.

[0039] Specifically in the present application, a plurality of seepage holes 310 are provided, and the water bag 300 is provided with seepage holes 310 on the surface close to the upper simulation body 210 and the lower simulation body 220. Through the above arrangement, it is possible to simulate the situation of water gushing in multiple places in the goaf through multiple seepage holes 310, thereby improving the diversity of simulation. Specifically, each seepage hole 310 is provided with a plugging member, such as a stop valve, so that the speed of water seepage can be adjusted to improve the authenticity of water gushing simulation, and the control of the water seepage sequence of the seepage points can be realized.

[0040] like Figure 3 As shown, in the first embodiment of the present application, a water bag 300 is provided, and by providing a water bag 300, the entire area can be mined and water gushed.

[0041] In other embodiments of the present application, different from the first embodiment, a plurality of water bags 300 are provided, and the plurality of water bags 300 are arranged in an array between the upper simulation body 210 and the lower simulation body 220. In this way, more complex mining conditions and water gushing conditions can be simulated.

[0042] like Figure 1 and 4 As shown, in the second embodiment of the present application, a plurality of water bags 300 are sequentially distributed along the width direction, and the hollow layer and the liquid storage cavity of each water bag 300 are independently controlled, so as to simulate the situation of segmented mining of coal seams.

[0043] In the third to fifth embodiments of the present application, a plurality of water bags 300 are arranged in sequence along the length direction and the width direction.

[0044] like Figure 5 As shown, in the third embodiment of the present application, the plurality of water bags 300 include a plurality of first simulation groups and a plurality of second simulation groups, the first simulation groups and the second simulation groups are alternately distributed in the width direction, the hollow layers of the water bags 300 of the plurality of first simulation groups are connected, and the liquid storage chambers of the water bags 300 of the plurality of first simulation groups are connected. In this embodiment, by connecting the plurality of liquid storage chambers and the vacuum layer of the first simulation group, the mining situation of strip filling can be simulated by controlling the state change of the first simulation group.

[0045] like Figure 6As shown, in the fourth embodiment of the present application, the hollow layers of two adjacent water bags 300 are connected, and the liquid storage chambers of two adjacent water bags 300 are connected. In this embodiment, the state changes of all water bags 300 can be controlled to simulate the mining of the entire area.

[0046] like Figure 7 As shown, in the fifth embodiment of the present application, the hollow layers of two adjacent water bags 300 are not connected, and the liquid storage chambers of two adjacent water bags 300 are not connected. In this embodiment, the state change of a certain water bag 300 can be controlled to simulate the situation of room-pillar filling and mining.

[0047] like Figure 8 As shown, in some embodiments of the present application, ice cubes can also be placed in the liquid storage cavity to simulate coal seams at different heights. Before the high-temperature refrigerant is introduced into the hollow layer, ice cubes of different shapes can be preset in the liquid storage cavity to simulate the undulating heights of different coal seams, thereby improving the authenticity of the simulation experiment.

[0048] Reference Figures 2 to 8 As shown, the water bag 300 involved in simulating the change of the coal seam in the embodiment of the present application is the water bag 300 in the shaded part.

[0049] According to an embodiment of the present invention, a method for a three-dimensional physical similarity simulation experiment of coal mining is also provided. The method for a three-dimensional physical similarity simulation experiment of coal mining is performed using the above-mentioned three-dimensional physical similarity simulation experiment device for coal mining, and the method comprises:

[0050] Step 1: prefabricate the box 100 according to the experimental requirements;

[0051] Step 2: Lay the lower layer simulation body 220 in the box;

[0052] Step 3: Lay the water bag 300 on the lower simulated body and close the blocking piece;

[0053] Step 4: close the liquid outlet and inject water into the liquid storage chamber through the liquid inlet;

[0054] Step 5: close the liquid inlet and the material outlet, and introduce low-temperature refrigerant into the hollow layer through the material inlet to solidify the water in the liquid storage cavity;

[0055] Step 6, closing the feed port and laying the upper simulation body 210 on the water bag 300;

[0056] Step seven, open the plugging parts, the discharge port, the feed port and the liquid outlet, introduce high-temperature refrigerant into the hollow layer through the feed port, and observe the changes of the formation simulation body in the box.

[0057] In step 1, the box 100 can be made of materials such as glass and acrylic plate to facilitate observation.

[0058] In step 2 and step 6, similar simulation materials such as quartz sand, river sand, dimethyl silicone oil, cement, calcium carbonate, lime powder, etc. can be used to prefabricate the formation simulation body, and the ratio of similar materials depends on the type of rock formation being simulated.

[0059] In step three, the water bag 300 can be laid according to the actual state to be simulated by selecting the conditions in embodiments 1 to 5 of the present application.

[0060] Specifically, after step seven is completed, the plugging component can be closed and steps four and five can be repeated, so that the filling simulation in the goaf can be realized.

[0061] 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, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0062] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0063] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0064] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0065] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A three-dimensional physical similarity simulation experimental device for coal mining, characterized in that: The three-dimensional physical similarity simulation experimental device for coal mining comprises: Box (100); A formation simulation body is arranged in the box (100), the formation simulation body comprises an upper layer simulation body (210) and a lower layer simulation body (220), and the upper layer simulation body (210) and the lower layer simulation body (220) are arranged in layers at intervals along a height direction; a water bag (300) disposed between the upper layer simulation body (210) and the lower layer simulation body (220), the water bag (300) having a liquid storage cavity, a liquid inlet and a liquid outlet, the liquid inlet and the liquid outlet both being in communication with the liquid storage cavity, and the water bag (300) being in communication with the outside of the box body (100) via the liquid inlet and the liquid outlet; a temperature control structure, arranged on the water bag (300), the temperature control structure being capable of lowering the temperature of the liquid in the liquid storage chamber to solidify the liquid in the liquid storage chamber, or raising the temperature of the liquid in the liquid storage chamber to melt the liquid in the liquid storage chamber; In particular, water seepage holes (310) are further provided on the upper and lower walls of the water bag (300), the water seepage holes (310) being connected to the liquid storage chamber, and a blocking piece is provided on the water bag (300), the blocking piece opens or blocks the water seepage hole (310), and the water bag (300) can discharge water into the box body (100) through the water seepage hole (310).

2. The three-dimensional physical similarity simulation experimental device for coal mining according to claim 1 is characterized in that: The side wall of the water bag (300) has an inner layer and an outer layer that are spaced apart, a hollow layer is formed between the inner layer and the outer layer, and the hollow layer forms the temperature control structure. A feed port and a discharge port are provided on the side wall of the water bag (300), and the feed port and the discharge port are both connected to the hollow layer. The hollow layer is used to pass a refrigerant to control the temperature of the water bag (300).

3. The three-dimensional physical similarity simulation experimental device for coal mining according to claim 1 is characterized in that: A liquid inlet pipe (321) is provided at the liquid inlet, a liquid outlet pipe (322) is provided at the liquid outlet, and a first flow control valve (323) and a flow detection element (324) are provided on both the liquid inlet pipe (321) and the liquid outlet pipe (322).

4. The three-dimensional physical similarity simulation experimental device for coal mining according to claim 2 is characterized in that: A feed pipe (331) is provided at the feed port, and a discharge pipe (332) is provided at the discharge port. A second flow control valve (333) and a temperature detection component (334) are provided on both the feed pipe (331) and the discharge pipe (332).

5. The three-dimensional physical similarity simulation experimental device for coal mining according to claim 1 is characterized in that: A plurality of water seepage holes (310) are provided, and the water seepage holes (310) are provided on the surfaces of the water bag (300) close to the upper layer simulation body (210) and the lower layer simulation body (220).

6. The three-dimensional physical similarity simulation experimental device for coal mining according to claim 1 is characterized in that: A plurality of the water bags (300) are provided, and the plurality of the water bags (300) are arranged in an array between the upper layer simulation body (210) and the lower layer simulation body (220).

7. The three-dimensional physical similarity simulation experimental device for coal mining according to claim 6 is characterized in that: The plurality of water bags (300) include a plurality of first simulation groups and a plurality of second simulation groups, the first simulation groups and the second simulation groups are alternately distributed in sequence along the width direction, the hollow layers of the plurality of water bags (300) of the first simulation groups are connected, and the liquid storage chambers of the plurality of water bags (300) of the first simulation groups are connected.

8. The three-dimensional physical similarity simulation experimental device for coal mining according to claim 6 is characterized in that: The hollow layers of two adjacent water bags (300) are connected, and the liquid storage cavities of two adjacent water bags (300) are connected.

9. The three-dimensional physical similarity simulation experimental device for coal mining according to claim 6 is characterized in that: The hollow layers of two adjacent water bags (300) are not connected, and the liquid storage cavities of two adjacent water bags (300) are not connected.

10. The three-dimensional physical similarity simulation experimental device for coal mining according to claim 1 is characterized in that: Ice cubes are arranged in the liquid storage cavity, and the ice cubes are used to simulate coal seams at different heights.

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