A coal and coalbed methane in-situ co-mining system and method suitable for soft coal seams

Abstract

The present invention discloses a system and method for in-situ co-mining of coal and coalbed methane suitable for soft coal seams, which relates to the field of coal mining technology. The system comprises a shaft, a vertical shaft lifting unit, a mining and crushing unit, a secondary crushing unit, a pumping unit, a separation and collection unit, and a roof stability monitoring unit. The mining and crushing unit comprises a shell, a mining mechanism, a water jet mechanism, a transmission mechanism, a crushing mechanism, and a moving mechanism. A bottom storage tank is provided at the bottom of the shaft. The secondary crushing unit is provided at the bottom of the shaft and is located above the bottom storage tank. The pumping unit is used to pump the fluidized coal-water mixture in the bottom storage tank that has been secondary crushed by the secondary crushing unit into the separation and collection unit. The separation and collection unit is used to separate and collect coal, water, and coalbed methane. The system and method reduce costs, shorten the mining cycle, avoid damage to equipment and affect the normal progress of the process, and increase the scope of mining in the coal seam.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mining, and in particular to an in-situ coal and coalbed methane co-mining system and method suitable for soft coal seams. Background Art

[0002] Coal mines in soft coal seams are numerous and widely distributed. These coal seams are typically characterized by soft coal structure, high gas content, low permeability, difficulty in gas extraction, and a high risk of gas disasters, which can easily lead to gas safety accidents. Therefore, the mining of coal resources and the effective extraction of gas face significant technical challenges. Currently, with the introduction of coal and coalbed methane co-mining technology, new solutions have been provided to overcome these challenges. To improve the utilization efficiency of coal mine resources and the safety of mining, scholars in related fields have developed an integrated model of protective layer pressure relief coal and gas co-mining and its supporting process technologies, and explored new permeability enhancement methods such as sonic vibration, ultrasonic waves, deep hole pre-splitting blasting, and integrated water jet drilling and cutting. However, existing coal and coalbed methane co-mining technologies have problems such as large gas extraction tunnels and drilling projects, high costs, and long cycles, which seriously restrict the implementation of these coal and coalbed methane technologies, especially for soft coal seams. At the same time, since the drilling position and water jet device are in a fixed state, the mining range in the coal seam is limited. At the same time, the coal body flushed by the water jet cannot ensure that the particle size of the coal powder particles is within the range allowed by the pumping device, which can easily cause problems such as pump jamming, damage equipment, and affect the normal progress of the process. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides a system and method for in-situ co-mining of coal and coalbed methane suitable for soft coal seams, which reduces costs, shortens the mining cycle, avoids damage to equipment and affects the normal progress of the process, and increases the mining range in the coal seam.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides an in-situ co-mining system of coal and coalbed methane suitable for soft coal seams, comprising a shaft, a vertical shaft lifting unit, a mining and crushing unit, a secondary crushing unit, a pumping unit, a separation and collection unit, and a roof stability monitoring unit. The roof stability monitoring unit is used to monitor the strain information of the roof in real time and issue an early warning. The vertical shaft lifting unit includes a device for conveying equipment into the shaft. The mining and crushing unit comprises a shell, a mining mechanism, a water jet mechanism, a transmission mechanism, a crushing mechanism, and a moving mechanism. The moving mechanism is arranged at the bottom of the shell, the mining mechanism and the water jet mechanism are arranged at the front end of the shell, the crushing mechanism is arranged at the rear end of the shell, and the transmission mechanism is arranged at the bottom end of the shell. The mechanism is arranged in the shell and is used to transport the coal body cut by the mining mechanism to the crushing mechanism, and the water sprayed by the water jet mechanism is used to convert the coal powder crushed by the crushing mechanism into a fluidized coal-water mixture; a bottom storage tank is provided at the bottom of the wellbore, and the secondary crushing unit is arranged at the bottom of the wellbore and located above the bottom storage tank. The secondary crushing unit is used to perform secondary crushing on the fluidized coal-water mixture, and the pumping unit is used to pump the fluidized coal-water mixture in the bottom storage tank that has been secondary crushed by the secondary crushing unit to the separation and collection unit, and the separation and collection unit is used to realize the separation and collection of coal, water and coalbed methane.

[0006] Preferably, the secondary crushing unit includes a bracket, a crushing bin, a feeding bin, a crushing mechanism and a crushing motor, the bracket is arranged above the bottom storage tank, the crushing bin is arranged on the bracket, the feeding bin is arranged on the top of the crushing bin, the crushing mechanism is arranged in the crushing bin, and the crushing motor is used to provide power to the crushing mechanism.

[0007] Preferably, the crushing mechanism includes an active crushing roller and a driven crushing roller, both ends of the active crushing roller are rotatably mounted in the crushing bin, both ends of the driven crushing roller are rotatably mounted in the crushing bin, the driven crushing roller and the active crushing roller are meshed, and the crushing motor is used to drive the active crushing roller to rotate.

[0008] Preferably, the feed bin is an inverted cone structure, and the area of ​​the top of the feed bin is larger than the area of ​​the bottom of the shaft.

[0009] Preferably, it also includes a plurality of transfer storage tanks arranged in sequence from bottom to top above the bottom storage tank, and the plurality of transfer storage tanks are all arranged on the same side of the wellbore. The pumping unit includes a bottom pumping mechanism, a top pumping mechanism and an intermediate pumping mechanism. The bottom pumping mechanism is used to pump the fluidized coal-water mixture in the bottom storage tank to the adjacent transfer storage tank, the intermediate pumping mechanism is used to pump the fluidized coal-water mixture in the lower transfer storage tank of the two adjacent transfer storage tanks to the upper transfer storage tank, and the top pumping mechanism is used to pump the fluidized coal-water mixture in the uppermost transfer storage tank to the separation and collection unit.

[0010] Preferably, the bottom pumping mechanism includes a bottom pumping pipe and a bottom particle pump arranged on the bottom pumping pipe, and the two ends of the bottom pumping pipe are respectively connected to the bottom storage tank and the adjacent transfer storage tank; the intermediate pumping mechanism includes an intermediate pumping pipe and an intermediate particle pump arranged on the intermediate pumping pipe, and the two ends of the intermediate pumping pipe are respectively connected to the two adjacent transfer storage tanks; the top pumping mechanism includes a top pumping pipe and a top particle pump arranged on the top pumping pipe, and the two ends of the top pumping pipe are respectively connected to the topmost transfer storage tank and the separation and collection unit.

[0011] Preferably, the mining mechanism includes a cutterhead housing, a cutting cutterhead, a cutterhead drive assembly and a roller cutter group, the cutterhead housing is arranged at the front end of the shell, the cutting cutterhead is rotatably installed at the front end of the cutterhead housing, the cutterhead drive assembly is arranged in the cutterhead housing and is used to drive the cutting cutterhead to rotate, the roller cutter group is provided at the front end of the cutting cutterhead, a plurality of feed holes are provided on the cutting cutterhead, and a plurality of mounting holes are provided on the cutting cutterhead; the water jet mechanism includes a water supply assembly and a plurality of water jet nozzles, each of the mounting holes is provided with a water jet nozzle, the water supply assembly is arranged on the shell and is used to supply water to the water jet nozzles; a transmission chamber and a crushing chamber are sequentially provided in the shell from front to back, the front end of the transmission chamber is connected to the outlet at the rear end of the cutterhead housing, one end of the transmission mechanism is installed in the cutterhead housing, and the other end is installed in the transmission chamber, the crushing mechanism is arranged in the crushing chamber, and the rear end of the shell is provided with a discharge port corresponding to the position of the crushing chamber.

[0012] The present invention also provides an in-situ coal and coalbed methane co-mining method applicable to soft coal seams, comprising the following steps:

[0013] Step 1: Based on the surface drilling project, a wellbore is excavated. The depth of the wellbore is greater than the depth of the coal seam. The wellbore is used to build a well lifting system, and a bottom storage tank with a size greater than the diameter of the wellbore is excavated at the bottom of the wellbore to receive the fluidized coal-water mixture flowing back.

[0014] Step 2: Install a secondary crushing unit above the bottom storage tank, and connect the pumping unit to the bottom storage tank and the separation and collection unit on the ground;

[0015] Step 3: Before starting coal and coalbed methane mining operations, deploy the roof stability monitoring unit;

[0016] Step 4: Use the vertical shaft lifting system to transport the mining and crushing unit downward along the shaft to a position close to the top of the coal seam, with the front end of the mining and crushing unit facing the coal seam. After the mining mechanism of the mining and crushing unit contacts the coal seam, it cuts the coal seam along a certain upward coal mining route. The cut coal body is then transported to the crushing mechanism at the rear end of the mining and crushing unit through the transmission mechanism for crushing. The crushed coal powder falls into the mining tunnel. The water jetted by the water jet mechanism at the front end of the mining and crushing unit forms a water flow in the mining tunnel, which converts the coal powder into fluidized state. Driven by the water flow and the inclination of the mining tunnel, the fluidized coal-water mixture continuously flows toward the rear of the mining tunnel until it flows to the shaft and falls.

[0017] Step 5: The fluidized coal-water mixture falls into the secondary crushing unit for further crushing, and then falls into the bottom storage tank;

[0018] Step 6: Use the pumping unit to transport the fluidized coal-water mixture in the bottom storage tank from the bottom of the well to the separation and collection unit on the ground for separation and collection.

[0019] Preferably, in step 4, for a nearly horizontal coal seam, an upward mining method is adopted, and during the mining process, the moving direction of the mining and crushing unit should form a certain angle with the upward inclination of the coal seam;

[0020] For inclined coal seams, during mining, the mining and crushing unit moves in the same direction as the coal seam inclination, and mining is carried out along the upward inclination of the coal seam.

[0021] Mining is carried out using a roundabout mining method. Within the same mining plane, the mining and crushing unit starts to make an elliptical motion starting from the boundary between the shaft and the coal seam. When the mining and crushing unit returns to the shaft, the mining distance is expanded and the elliptical motion is continued. This cycle is repeated several times until it returns to the starting point.

[0022] For coal seams with a certain thickness, they are mined layer by layer from top to bottom. After a certain range of coal seams close to the roof rock layer are mined, when the mining and crushing unit returns to the starting point, the vertical shaft lifting system is used to lower the mining and crushing unit for a distance, and mining is carried out again using the same roundabout mining method until it approaches the bottom rock layer.

[0023] Preferably, in step 4, for a nearly horizontal coal seam, an upward mining method is adopted, and during the mining process, the moving direction of the mining and crushing unit should form a certain angle with the upward inclination of the coal seam;

[0024] For inclined coal seams, during mining, the mining and crushing unit moves in the same direction as the coal seam inclination, and mining is carried out along the upward inclination of the coal seam.

[0025] Mining is carried out using a forked mining method. Within the same mining plane, the mining and crushing unit takes the junction of the shaft and the coal seam as the starting point, and the mining and crushing unit mines forward for a certain distance to form a main mining tunnel, and then makes a 1 / 4 elliptical motion to the left of the main mining tunnel. When the mining and crushing unit reaches the apex of the ellipse, the mining and crushing unit begins to rotate 90° to the right and mines forward for a certain distance, and then the mining and crushing unit continues to rotate 90° to the right and makes a 1 / 4 elliptical motion next to the previous mining trajectory; when the mining and crushing unit reaches the main mining tunnel, the mining and crushing unit continues to mine forward for a certain distance, and then makes a 1 / 4 elliptical motion to the left of the main mining tunnel. When the mining and crushing unit reaches the apex of the ellipse, the mining and crushing unit begins to rotate 90° to the right and mines forward for a certain distance, and then the mining and crushing unit continues to rotate 90° to the right and makes a 1 / 4 elliptical motion next to the previous mining trajectory. Make a 1 / 4 elliptical motion, and repeat this cycle several times; after mining forward for a distance along the inclination of the coal seam, return to the main mining tunnel, the mining and crushing unit starts to make a 1 / 4 elliptical motion to the right side of the main mining tunnel, and when the mining and crushing unit reaches the apex of the ellipse, the mining and crushing unit rotates 90° to the right and mines a certain distance backward, and then the mining and crushing unit continues to rotate 90° to the right and makes a 1 / 4 elliptical motion next to the previous mining trajectory, and when it reaches the main mining tunnel, move backward for a certain distance along the main mining tunnel, and the mining and crushing unit makes a 1 / 4 elliptical motion to the right side of the main mining tunnel, and when the mining and crushing unit reaches the apex of the ellipse, the mining and crushing unit rotates 90° to the right and mines a certain distance backward, and then the mining and crushing unit continues to rotate 90° to the right and makes a 1 / 4 elliptical motion next to the previous mining trajectory, and repeat this cycle several times until it reaches the starting position;

[0026] For coal seams with a certain thickness, they are mined layer by layer from top to bottom. After a certain range of coal seams close to the roof rock layer is mined, when the mining and crushing unit returns to the starting point, the vertical shaft lifting system is used to lower the mining and crushing unit for a distance, and mining is carried out again using the same forked mining method until it approaches the bottom rock layer.

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

[0028] The in-situ coal and coalbed methane co-mining system for soft coal seams of the present invention utilizes a mining and crushing unit to mine and crush the coal along an upward mining route. The coal is transformed into a fluidized resource under the impact of water jets. Under the action of hydraulic scouring and its own gravity, it flows through the mined mining tunnels to the shaft, flows downward along the shaft wall, and reaches the secondary crushing unit at the bottom of the shaft. This unit further reduces the particle size of the coal powder through extrusion and crushing, reducing it to a size suitable for pumping and dropping it into a bottom storage tank. The fluidized coal-water mixture is then transported to the surface by a pumping unit. At the surface, the coal, water, and coalbed methane are separated and collected by a separation and collection unit, thus completing the entire in-situ coal and coalbed methane co-mining process for soft coal seams. After the mined coal is crushed multiple times, the overall particle size of the fluidized coal-water mixture is reduced to the maximum particle size allowed by the pumping unit, avoiding damage to equipment and affecting the normal operation of the process. The mining and crushing unit can be flexibly moved, increasing the scope of mining in the coal seam. The system and method of the present invention save manpower and material resources, as well as preparation time for mining to a great extent, and do not require the advance development of tunnels and chambers, and do not require ventilation, thereby reducing the cost of tunnel construction, maintenance and coal transportation, increasing the recovery rate of coal resources, greatly improving the intelligence level of coal mining, and shortening the mining cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 A schematic structural diagram of the in-situ coal and coalbed methane co-mining system applicable to soft coal seams provided by the present invention;

[0031] Figure 2 Schematic diagram of mining inclined coal seams with the in-situ coal and coalbed methane co-mining system applicable to soft coal seams provided by the present invention;

[0032] Figure 3A schematic structural diagram of a secondary crushing unit in an in-situ coal and coalbed methane co-mining system applicable to soft coal seams provided by the present invention;

[0033] Figure 4 A three-dimensional structural diagram of the mining and crushing unit in the in-situ coal and coalbed methane co-mining system applicable to soft coal seams provided by the present invention;

[0034] Figure 5 This is a diagram showing the internal structure of the mining and crushing unit in the in-situ coal and coalbed methane co-mining system applicable to soft coal seams provided by the present invention;

[0035] Figure 6 A front view of the mining and crushing unit in the in-situ coal and coalbed methane co-mining system applicable to soft coal seams provided by the present invention;

[0036] Figure 7 A top view of the in-situ coal and coalbed methane mining method for soft coal seams provided by the present invention, which adopts a circuitous mining method;

[0037] Figure 8 A three-dimensional structural diagram of the in-situ coal and coalbed methane mining method for soft coal seams provided by the present invention, which adopts a circuitous mining method;

[0038] Figure 9 A front view of the in-situ coal and coalbed methane mining method for soft coal seams provided by the present invention, which adopts a circuitous mining method;

[0039] Figure 10 A three-dimensional structural diagram of the in-situ coal and coalbed methane co-mining method for soft coal seams provided by the present invention, which adopts a circuitous mining method in multiple wellbores;

[0040] Figure 11 A top view of the decomposed steps of the in-situ coal and coalbed methane mining method for soft coal seams using a circuitous mining method provided by the present invention;

[0041] Figure 12 A top view of the in-situ coal and coalbed methane mining method for soft coal seams provided by the present invention, which adopts a bifurcated mining method;

[0042] Figure 13 A three-dimensional structural diagram of the in-situ coal and coalbed methane mining method for soft coal seams provided by the present invention, which adopts a bifurcated mining method;

[0043] Figure 14 A front view of the in-situ coal and coalbed methane mining method for soft coal seams provided by the present invention, which adopts a bifurcated mining method;

[0044] Figure 15A three-dimensional structural diagram of the in-situ coal and coalbed methane co-mining method for soft coal seams provided by the present invention, which adopts a bifurcated mining method in multiple wellbores;

[0045] Figure 16 A top view of the decomposed steps of the in-situ coal and coalbed methane co-mining method suitable for soft coal seams provided by the present invention using a bifurcated mining method.

[0046] Explanation of reference numerals: 1. Coal seam; 2. Roof rock layer; 3. Floor rock layer; 4. Bottom storage tank; 5. Transfer storage tank; 6. Secondary crushing unit; 61. Support; 62. Feed bin; 63. Crushing bin; 64. Active crushing roller; 65. Driven crushing roller; 7. Mining and crushing unit; 71. Shell; 72. Moving crawler; 73. Water pump; 74. Water pump motor; 75. Cutterhead shell; 76. Cutting disc; 77. Single-edged hob; 78. Double-edged hob; 79. Feed hole; 710. Water jet nozzle; 711. Cylindrical cavity; 712. Conical cavity; 713. Crushing cavity; 714. Screw; 715. Transmission motor; 716. Crushing blade; 8. Fluidized coal-water mixture; 9. Roof stability monitoring unit; 10. Shaft; 11. Vertical shaft lifting Downflow unit; 12. Separation and collection unit; 13. Water reservoir; 14. Bottom particle pump; 15. Middle particle pump; 16. Top particle pump; 17. First mining tunnel; 171. First circle mining route; 172. Second circle mining route; 173. Third circle mining route; 174. Fourth circle mining route; 175. Nth circle mining route; 18. First legacy coal pillar; 19. Second mining tunnel; 191. First fork mining tunnel; 192. Second fork mining tunnel; 193. Third fork mining tunnel; 194. Fourth fork mining tunnel; 195. Fifth fork mining tunnel; 196. Sixth fork mining tunnel; 197. Seventh fork mining tunnel; 198. Eighth fork mining tunnel; 20. Second legacy coal pillar; 21. Main mining tunnel. DETAILED DESCRIPTION

[0047] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0048] The purpose of the present invention is to provide a system and method for in-situ co-mining of coal and coalbed methane suitable for soft coal seams, which reduces costs, shortens the mining cycle, avoids damage to equipment and affects the normal progress of the process, and increases the mining range in the coal seam.

[0049] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] like Figures 1-16 As shown, this embodiment provides a coal and coalbed methane in-situ co-mining system suitable for soft coal seams, including a wellbore 10, a vertical shaft lifting unit 11, a mining and crushing unit 7, a secondary crushing unit 6, a pumping unit, a separation and collection unit 12 and a roof stability monitoring unit 9. The roof stability monitoring unit 9 is used to monitor the strain information of the roof in real time and issue an early warning. The vertical shaft lifting unit 11 includes a device for conveying equipment into the wellbore 10. The mining and crushing unit 7 includes a shell 71, a mining mechanism, a water jet mechanism, a transmission mechanism, a crushing mechanism and a moving mechanism. The moving mechanism is arranged at the bottom of the shell 71. The moving mechanism is used to drive the entire equipment to move. The mining mechanism and the water jet mechanism are arranged at the front end of the shell 71, the crushing mechanism is arranged at the rear end of the shell 71, and the transmission mechanism is arranged at the bottom of the shell 71. It is placed in the shell 71 and is used to transport the coal body cut by the mining mechanism to the crushing mechanism. The water sprayed by the water jet mechanism is used to convert the coal powder crushed by the crushing mechanism into a fluidized coal-water mixture 8; a bottom storage tank 4 is provided at the bottom of the wellbore 10, and a secondary crushing unit 6 is provided at the bottom of the wellbore 10 and above the bottom storage tank 4. The secondary crushing unit 6 is used to perform secondary crushing on the fluidized coal-water mixture 8 to prevent the fluidized coal-water mixture 8 from entraining large-particle coal powder during the flow process, thereby affecting the subsequent pumping process; the pumping unit is used to pump the fluidized coal-water mixture 8 in the bottom storage tank 4 that has been secondary crushed by the secondary crushing unit 6 to the separation and collection unit 12, and the separation and collection unit 12 is used to realize the separation and collection of coal, water and coalbed methane.

[0051] In this embodiment, mining and crushing units 7 are used to mine and crush the coal along the ascending mining route. Under the impact of water jets, the coal is transformed into a fluidized resource. Under the influence of hydraulic scouring and gravity, it flows through the mined mining tunnels to the shaft 10, flowing downward along the shaft 10 wall to reach the secondary crushing unit 6 at the bottom of the shaft. This unit further reduces the coal powder particle size to a pumpable size through extrusion and crushing, and then drops into the bottom storage tank 4. The fluidized coal-water mixture is then transported to the surface by the pumping unit. At the surface, the coal, water, and coalbed methane are separated and collected by the separation and collection unit 12, thus completing the entire process of in-situ co-mining of soft coal and coalbed methane. After multiple crushing operations on the mined coal, the overall particle size of the fluidized coal-water mixture is reduced to the maximum particle size allowed by the pumping unit, avoiding damage to equipment and affecting the normal operation of the process. The mining and crushing unit 7 can be flexibly moved, increasing the mining range within the coal seam 1. The system and method of the present invention significantly saves manpower and material resources, as well as mining preparation time. It also eliminates the need for pre-development of tunnels and chambers, and eliminates the need for ventilation. This reduces tunnel construction, maintenance, and coal transportation costs, increases the recovery rate of coal resources, significantly enhances the intelligence level of coal mining, and shortens the mining cycle. Through unmanned underground operations, casualties are avoided, not only achieving optimal resource utilization but also protecting the mining area's ecological environment, effectively promoting the transition of coal resource mining to intelligent, unmanned mining.

[0052] Specifically, the vertical shaft lifting unit 11 includes a derrick, a steel wire rope, a shaft 10, an elevator, and a control system. The vertical shaft lifting unit 11 in this embodiment is a structure in the prior art.

[0053] Specifically, multiple wellbores 10 are set within the mining area, and the mining areas do not affect each other.

[0054] like Figure 3 As shown, the secondary crushing unit 6 includes a bracket 61, a crushing bin 63, a feed bin 62, a crushing mechanism and a crushing motor. The bracket 61 is arranged above the bottom storage tank 4, the crushing bin 63 is arranged on the bracket 61, the feed bin 62 is arranged on the top of the crushing bin 63, the crushing mechanism is arranged in the crushing bin 63, and the crushing motor is used to provide power to the crushing mechanism.

[0055] The crushing mechanism includes an active crushing roller 64 and a driven crushing roller 65. Both ends of the active crushing roller 64 are rotatably mounted in the crushing bin 63. Both ends of the driven crushing roller 65 are rotatably mounted in the crushing bin 63. The driven crushing roller 65 and the active crushing roller 64 are meshed with each other. The crushing motor is used to drive the active crushing roller 64 to rotate.

[0056] In this embodiment, the gap between the active crushing roller 64 and the driven crushing roller 65 is relatively small, so as to avoid the occurrence of large discharge particle size at the discharge port.

[0057] In order to conveniently receive the fluidized coal-water mixture 8 flowing down from the mining tunnel, the feed bin 62 is an inverted cone structure, and the area of ​​the top of the feed bin 62 is larger than the area of ​​the bottom of the shaft 10.

[0058] This embodiment also includes a plurality of transfer storage tanks 5 arranged sequentially from bottom to top above the bottom storage tank 4, and the plurality of transfer storage tanks 5 are all located on the same side of the wellbore 10. The pumping unit includes a bottom pumping mechanism, a top pumping mechanism, and an intermediate pumping mechanism. The bottom pumping mechanism is used to pump the fluidized coal-water mixture 8 in the bottom storage tank 4 to the adjacent transfer storage tank 5. The intermediate pumping mechanism is used to pump the fluidized coal-water mixture 8 in the lower transfer storage tank 5 of the two adjacent transfer storage tanks 5 to the upper transfer storage tank 5. The top pumping mechanism is used to pump the fluidized coal-water mixture 8 in the uppermost transfer storage tank 5 to the separation and collection unit 12. The transfer storage tank 5 serves as a transfer station in the pumping process of the fluidized coal-water mixture 8 until the fluidized coal-water mixture 8 is transported to the ground.

[0059] The bottom pumping mechanism includes a bottom pumping pipe and a bottom particle pump 14 arranged on the bottom pumping pipe, and the two ends of the bottom pumping pipe are respectively connected to the bottom storage tank 4 and the adjacent transfer storage tank 5; the intermediate pumping mechanism includes an intermediate pumping pipe and an intermediate particle pump 15 arranged on the intermediate pumping pipe, and the two ends of the intermediate pumping pipe are respectively connected to the two adjacent transfer storage tanks 5; the top pumping mechanism includes a top pumping pipe and a top particle pump 16 arranged on the top pumping pipe, and the two ends of the top pumping pipe are respectively connected to the topmost transfer storage tank 5 and the separation and collection unit 12.

[0060] The maximum particle size of the conveying fluid of the bottom particle pump 14 and the intermediate particle pump 15 in this embodiment does not exceed 10 mm, and the maximum conveying head is 120 m. When conveying materials to a relatively high position, it is necessary to set up several intermediate particle pumps 15 in the longitudinal direction to convey the materials from the bottom of the wellbore 10 to the ground.

[0061] In this embodiment, the roof stability monitoring unit 9 is a distributed fiber-optic monitoring system for the roof rock layer 2. This system monitors roof strain in real time and issues early warnings by analyzing changes in optical signals transmitted through the optical fibers. The optical cables used in this distributed fiber-optic monitoring system for the roof rock layer 2 are selected to have high tensile and shear strength to prevent damage from being crushed by broken roof rock.

[0062] The separation and collection unit 12 in this embodiment is a coal-water-gas three-phase separation device.

[0063] like Figure 4-Figure 6As shown, the mining mechanism includes a cutterhead housing 75, a cutting disc 76, a cutterhead drive assembly and a roller cutter group. The cutterhead housing 75 is arranged at the front end of the shell 71, and the cutting disc 76 is rotatably installed at the front end of the cutterhead housing 75. The cutterhead drive assembly is arranged in the cutterhead housing 75 and is used to drive the cutting disc 76 to rotate. A roller cutter group is provided at the front end of the cutting disc 76. A plurality of feed holes 79 are provided on the cutting disc 76. The cut and crushed coal body can enter the cutterhead housing 75 through the feed holes 79. The cutting disc 76 is provided with a plurality of mounting holes.

[0064] The water jet mechanism includes a water supply component and multiple water jet nozzles 710, and each mounting hole is provided with a water jet nozzle 710. The water supply component is provided on the shell 71 and is used to supply water to the water jet nozzle 710; a transmission chamber and a crushing chamber 713 are provided in the shell 71 from front to back, and the front end of the transmission chamber is connected to the outlet at the rear end of the cutter disc shell 75. One end of the transmission mechanism is installed in the cutter disc shell 75, and the other end is installed in the transmission chamber. The transmission mechanism is used to transport the coal body in the cutter disc shell 75 backward to the crushing chamber 713. The crushing mechanism is provided in the crushing chamber 713, and the rear end of the shell 71 is provided with a discharge port corresponding to the position of the crushing chamber 713. The crushing mechanism is used to further crush the coal body transported to the crushing chamber 713 to avoid the production of large-particle coal blocks, and then discharged to the rear of the mining and crushing unit 7 through the discharge port.

[0065] This embodiment utilizes a technology combining a cutting disc 76 with a high-pressure water jet to achieve efficient coal cutting and crushing, significantly improving coal mining efficiency. The mined coal is transported to a crushing chamber 713 via a conveying mechanism for crushing by the crushing mechanism, further reducing the particle size of the cut coal. This ensures continuity between mining and transportation, reduces intermediate steps, and improves operational efficiency. The flushing action of the high-pressure water jet promotes the fluidization of the coal, facilitating its gravity-driven transport in the roadway, thereby reducing reliance on conventional conveying equipment. The crushed coal, under the dual effects of the high-pressure water flow and gravity, flows along the roadway into the shaft 10, achieving continuous coal transportation and reducing energy consumption and equipment requirements in the transportation process.

[0066] A support frame is provided in the cutter disc housing 75, and the central axis of the rear end of the cutting disc 76 is rotatably mounted on the support frame through a bearing, and the cutting disc 76 is fitted with the front end of the cutter disc housing 75, and the cutter disc drive assembly is used to drive the central axis to rotate.

[0067] The cutterhead drive assembly includes a cutterhead motor and a transmission gearbox. Both are located in the upper portion of the cutterhead housing 75. The cutterhead motor is connected to the power input of the transmission gearbox, while the power output of the transmission gearbox is connected to the central shaft. In this embodiment, the transmission gearbox and cutterhead motor are arranged in order from front to back.

[0068] The multiple cutter groups include multiple single-edged cutters 77 and multiple double-edged cutters 78. The cutting disc 76 has a spoke-shaped surface, with feed holes 79 located between any two adjacent spokes. The double-edged cutters 78 are concentrated in the center of the spokes, while the single-edged cutters 77 are arranged concentrically on the spokes to improve cutting efficiency and uniformity.

[0069] In this specific embodiment, the cutter head housing 75 and the cutting cutter head 76 are both made of welded steel structures, and the diameter of the cutting cutter head 76 is 0.3m to 0.5m.

[0070] In this embodiment, the housing 71 is a cylindrical flexible housing, which has a certain tolerance to the collision and friction generated when the mining and excavation integrated equipment moves in the coal seam 1 and is not prone to wear.

[0071] Specifically, the cylindrical flexible shell is made of thermoplastic polyurethane or carbon fiber composite material, which has wear resistance, flexibility and tear resistance, can withstand large collisions and friction, and has good processing performance and plasticity.

[0072] The water supply assembly includes a water pump 73, a water pump motor 74, a rotary joint, a main hose, and multiple branch hoses. Both the water pump 73 and the water pump motor 74 are located on the upper portion of the housing 71. The water pump motor 74 is used to drive the water pump 73. One end of the main hose is connected to the outlet of the water pump 73 via a rotary joint. The other end of the main hose is connected to multiple branch hoses, each of which is connected to a water jet nozzle 710 at its end away from the main hose. The water jet nozzle 710 is located on the cutting disc 76 and rotates with the cutting disc 76. The rotary joint allows the multiple branch hoses and the main hose to rotate with the water jet nozzle 710.

[0073] In order to achieve a continuous supply of water resources, the inlet of the water pump 73 is connected to one end of a connecting hose, and the other end of the connecting hose is connected to a water source on the ground.

[0074] During operation, the water in the water pump 73 is converted into high-pressure water flow through the main hose and the branch hose, and is sprayed out by the water jet nozzle 710 to flush the coal body cut in front and soften the coal body in front of the equipment to reduce the strength of the coal body, promote the crushing process of the coal body and convert it into a form resource that is easy to transport. At the same time, it promotes the conversion of coal powder falling into the tunnel into a fluidized state that is easy to transport.

[0075] In this embodiment, the jet direction of the water jet nozzle 710 is perpendicular to the cutting disc 76. There are four water jet nozzles 710, which are distributed in the middle of the cutting disc 76 and are evenly distributed along the circumference of the cutting disc 76.

[0076] In this specific embodiment, both the main hose and the branch hose are high-pressure hoses.

[0077] The transmission mechanism includes a first support, a second support, a screw 714, and a transmission motor 715. The first support is located at the bottom of the cutterhead housing 75, and the second support is located at one end of the transmission chamber near the crushing chamber 713. The ends of the screw 714 are rotatably mounted in the first and second supports, respectively. The transmission motor 715 is located on the second support and is used to drive the screw 714. During operation, the transmission motor 715 drives the screw 714 to rotate, transporting the coal in the cutterhead housing 75 into the crushing chamber 713.

[0078] Specifically, one end of the screw rod 714 is rotatably mounted in the first support via a bearing, and the other end of the screw rod 714 is rotatably mounted in the second support via a bearing.

[0079] The crushing mechanism includes two crushing components, which are arranged in the crushing chamber 713 from left to right. The crushing components include a crushing motor, a rotating shaft and multiple crushing blades 716. The rotating shaft is vertically arranged in the crushing chamber 713, and the two ends of the rotating shaft are respectively rotatably mounted on the shell 71. Multiple crushing blades 716 are arranged in sequence on the rotating shaft along the axial direction. The crushing motor is arranged on the shell 71 and connected to the upper end of the rotating shaft. The multiple crushing blades 716 on the two rotating shafts are staggered.

[0080] During operation, the pulverizing motor is activated. When the pulverizing blades 716 come into contact with the coal, they are squeezed together to discharge small-sized coal powder. The two pulverizing motors control the two rotating shafts, which in turn control the rotation speed and direction of the pulverizing blades 716 on the two rotating shafts to optimize the pulverization effect.

[0081] In this specific embodiment, the crushing blade 716 is made of special alloy steel.

[0082] The transmission chamber includes a cylindrical chamber 711 and a conical chamber 712, arranged in sequence from front to back. The front end of the cylindrical chamber 711 is connected to the outlet at the rear end of the cutterhead housing 75, and the rear end of the conical chamber 712 is connected to the crushing chamber 713. The cross-sectional area of ​​the conical chamber 712 gradually increases from front to back, and the cross-sectional area at the front end of the conical chamber 712 is the same as the cross-sectional area of ​​the cylindrical chamber 711. In this embodiment, the cylindrical chamber 711 is a cylindrical chamber.

[0083] The second support is set at the connection between the cylindrical cavity 711 and the conical cavity 712, and the transmission motor 715 is set in the conical cavity 712. The conical cavity 712 is connected to the cylindrical cavity 711 with the screw 714 and the crushing cavity 713 to achieve smooth transition and continuous crushing of the cut coal.

[0084] The moving mechanism includes a moving track 72 and a track motor. The moving track 72 is arranged at the bottom of the shell 71. The track motor is used to drive the moving track 72 to move. The moving track 72 is controlled by the track motor to realize the movement and steering of the entire equipment, so that it can move and turn freely and has strong flexibility.

[0085] The mining and crushing unit 7 in this embodiment is equipped with a mobile crawler 72, which can move and turn autonomously in the tunnel, thereby improving the maneuverability and flexibility of the equipment, realizing intelligent unmanned mining of coal mines, and improving the safety of coal mining.

[0086] The cutterhead motor, water pump motor 74, transmission motor 715, crushing motor and crawler motor in this embodiment are all high-power motors to ensure the continuity and efficiency of the equipment during the tunnel excavation process.

[0087] The mining and crushing unit 7 in this embodiment integrates mining, transportation, crushing, movement, and fluidization processing in one device. It features a compact structure, small overall dimensions, and minimal space occupation. Disturbance to the coal seam 1 during the mining process is minimized, effectively protecting the structural integrity of the coal seam 1, reducing impacts on the surrounding environment, improving mining efficiency, and reducing mining costs. This device is a compact, integrated, and highly efficient integrated mining and crushing device. The mining and crushing unit 7 in this embodiment achieves mining and crushing of the coal body, while simultaneously converting the crushed coal body into a transportable fluidized resource. This not only avoids dust pollution in the roadway, but also adapts to narrow mining spaces, improving operational efficiency under complex geological conditions, and achieving the goal of safe and efficient in-situ mining of coal reservoirs.

[0088] This embodiment also provides a method for in-situ co-mining of coal and coalbed methane applicable to soft coal seams, comprising the following steps:

[0089] Step 1: Based on the ground drilling project, a large-diameter wellbore 10 is excavated. The depth of the wellbore 10 must be greater than the depth of the coal seam 1. The wellbore 10 is used to build a well lifting system, and a bottom storage tank 4 with a size larger than the diameter of the wellbore 10 is excavated at the bottom of the wellbore 10 to receive the fluidized coal-water mixture 8 that flows back.

[0090] Step 2: Install a secondary crushing unit 6 above the bottom storage tank 4, and connect the pumping unit to the bottom storage tank 4 and the separation and collection unit 12 on the ground. Depending on the specific depth of the coal seam 1 and the head of the particle pump, multiple transfer storage tanks 5 are installed at intervals along the side of the wellbore 10 to serve as transfer stations during the pumping process of the fluidized coal-water mixture 8 until the fluidized coal-water mixture 8 is transported to the ground.

[0091] Step 3: Before coal and coalbed methane mining operations, first deploy the roof stability monitoring unit 9. The distributed optical fiber monitoring system for the roof stratum 2 in this embodiment can determine the maximum mining range of the mining and crushing unit 7 during coal tunneling by monitoring the roof stability.

[0092] Step 4: Use the vertical shaft lifting system to transport the mining and crushing unit 7 downward along the shaft 10 to a position near the top of the coal seam 1. The front end of the mining and crushing unit 7 faces the coal seam 1. After the mining mechanism of the mining and crushing unit 7 contacts the coal seam 1, it cuts the coal seam 1 along a certain upward coal mining route. The cut coal body is then transported to the crushing mechanism at the rear end of the mining and crushing unit 7 through the transmission mechanism for crushing. The crushed coal powder falls into the mining tunnel. The water jetted by the water jet mechanism at the front end of the mining and crushing unit 7 forms a water flow in the mining tunnel, which converts the coal powder into fluidized state. Driven by the water flow and the inclination of the mining tunnel, the fluidized coal-water mixture 8 continues to flow toward the rear of the mining until it flows to the shaft 10 and falls.

[0093] Step 5: The fluidized coal-water mixture 8 falls into the secondary crushing unit 6 and is crushed again, and then falls into the bottom storage tank 4; through the extrusion between the crushing rollers in the crushing bin, the fluidized coal-water mixture 8 falling into the bottom storage tank 4 does not contain large particles of coal powder, thereby ensuring that the particle size of the fluidized coal-water mixture 8 meets the maximum particle size for pumping, and avoiding large-particle coal powder being entrained in the fluidized coal powder mixture, which affects the subsequent pumping process.

[0094] Step 6: Use a pumping unit to transport the fluidized coal-water mixture 8 from the bottom of the well to the surface separation and collection unit 12 for separation and collection. Separation and collection unit 12 separates and collects the coal, water, and coalbed methane. The separated water is stored in a water reservoir 13 for recycling.

[0095] like Figure 7-11 As shown, in this specific embodiment, in step four, for the nearly horizontal coal seam (<5°), an upward mining method is adopted. During the mining process, the moving direction of the mining and crushing unit 7 must form a certain angle with the upward inclination of the coal seam 1, and the angle should not be too large.

[0096] For inclined coal seams, gently inclined coal seams (5°~10°), inclined coal seams (10°~45°) and steeply inclined coal seams, during the mining process, the moving direction of the mining and crushing unit 7 is consistent with the inclination of the coal seam 1, and mining is carried out along the upward inclination of the coal seam 1.

[0097] In order to ensure the stability of the coal seam 1 and the mining tunnel as much as possible, a first residual coal pillar 18 is left in the coal seam 1 for support, and a roundabout mining method is adopted. Within the same mining plane, the mining and crushing unit 7 starts to make elliptical motion with the junction of the shaft 10 and the coal seam 1 as the starting point. When the mining and crushing unit 7 returns to the shaft 10, the mining distance is expanded and the elliptical motion is continued. In this way, the cycle is repeated several times and returns to the starting point.

[0098] For a coal seam 1 with a certain thickness, it is mined layer by layer from top to bottom. After a certain range of the coal seam 1 near the roof rock layer 2 is mined, when the mining and crushing unit 7 returns to the starting point, the mining and crushing unit 7 is lowered a certain distance using the vertical shaft lifting system, and mining is carried out again using the same roundabout mining method until it approaches the bottom rock layer 3.

[0099] Specifically, the mining and crushing unit 7 mines the coal seam 1 along the elliptical first mining route 171. When the mining returns to the starting point after one round, the mining angle and mining range are increased, and mining continues along the second mining route 172. When the mining returns to the starting point after one round, the mining angle and mining range are further increased, and mining continues along the third mining route 173. Subsequently, when the mining returns to the starting point after one round, the mining angle and mining range are further increased, and mining continues along the fourth mining route 174. This cycle repeats until mining is performed along the nth mining route 175. After the upper plane is mined to a certain range, mining is then carried out vertically downwards, sequentially toward the middle and bottom of the coal seam 1. The first mining route 171, the second mining route 172, the third mining route 173, the fourth mining route 174, and the nth mining route 175 are collectively referred to as the first mining roadway 17.

[0100] like Figure 12-16 As shown, in another specific embodiment, in step four, for the nearly horizontal coal seam (<5°), an upward mining method is adopted. During the mining process, the moving direction of the mining and crushing unit 7 must form a certain angle with the upward inclination of the coal seam 1, and the angle should not be too large.

[0101] For inclined coal seams, gently inclined coal seams (5°~10°), inclined coal seams (10°~45°) and steeply inclined coal seams, during the mining process, the moving direction of the mining and crushing unit 7 is consistent with the inclination of the coal seam 1, and mining is carried out along the upward inclination of the coal seam 1.

[0102] In order to ensure the stability of the coal seam 1 and the mining tunnel as much as possible, a second residual coal pillar 20 is left in the coal seam 1 for support, and a bifurcated mining method is adopted for mining. In the same mining plane, the mining and crushing unit 7 takes the junction of the shaft 10 and the coal seam 1 as the starting point, and the mining and crushing unit 7 mines forward for a certain distance to form the mining main tunnel 21, and then makes a 1 / 4 elliptical motion to the left of the mining main tunnel 21. When the mining and crushing unit 7 reaches the apex of the ellipse, the mining and crushing unit 7 starts to rotate 90° to the right and mines forward for a certain distance, and then the mining and crushing unit 7 continues to rotate 90° to the right and makes a 1 / 4 elliptical motion next to the previous mining trajectory; when the mining and crushing unit 7 reaches the mining main tunnel 21, the mining and crushing unit 7 continues to mine forward for a certain distance, and then makes a 1 / 4 elliptical motion to the left of the mining main tunnel 21, and when the mining and crushing unit 7 reaches the apex of the ellipse, the mining and crushing unit 7 starts to rotate 90° to the right and mines forward for a certain distance, and then the mining and crushing unit 7 Continue to rotate 90° to the right, and make a 1 / 4 elliptical motion along the previous mining trajectory, and repeat this cycle several times; after mining forward for a distance along the inclination of the coal seam 1, return to the main mining tunnel 21, and the mining and crushing unit 7 begins to make a 1 / 4 elliptical motion to the right side of the main mining tunnel 21. When the mining and crushing unit 7 reaches the apex of the ellipse, the mining and crushing unit 7 rotates 90° to the right and mines a certain distance backward. Then, the mining and crushing unit 7 continues to rotate 90° to the right, and makes a 1 / 4 elliptical motion along the previous mining trajectory. When it reaches the main mining tunnel 21, it moves backward along the main mining tunnel 21 for a certain distance. The mining and crushing unit 7 makes a 1 / 4 elliptical motion to the right side of the main mining tunnel 21. When the mining and crushing unit 7 reaches the apex of the ellipse, the mining and crushing unit 7 rotates 90° to the right and mines a certain distance backward. Then, the mining and crushing unit 7 continues to rotate 90° to the right, and makes a 1 / 4 elliptical motion to the previous mining trajectory. Repeat this cycle several times until it reaches the starting position.

[0103] For a coal seam 1 with a certain thickness, it is mined layer by layer from top to bottom. After a certain range of the coal seam 1 near the roof rock layer 2 is mined, when the mining and crushing unit 7 returns to the starting point, the vertical shaft lifting system is used to lower the mining and crushing unit 7 for a distance, and mining is carried out again using the same forked mining method until it approaches the bottom rock layer 3.

[0104] Specifically, the mining and crushing unit 7 first makes a quarter-elliptical motion to the left at a certain angle along the first forked mining tunnel 191. When it reaches the apex of the quarter-ellipse, the mining and crushing unit 7 rotates 90° to the right, turns the body around, and mines forward for a certain distance. Then, the mining and crushing unit 7 continues to rotate 90° to the right, and returns to the main mining tunnel 21 along the second forked mining tunnel 192 next to the first forked mining tunnel 191. Then, the mining and crushing unit 7 rotates left, turns the body around to be parallel to the main mining tunnel 21, and makes a quarter-elliptical motion to the left at a certain angle along the third forked mining tunnel 193. When it reaches the apex of the quarter-ellipse, the mining and crushing unit 7 rotates 90° to the right, turns the body around, and mines forward for a certain distance. Then, the mining and crushing unit 7 continues to rotate 90° to the right, and returns to the main mining tunnel 21 along the fourth forked mining tunnel 194 next to the third forked mining tunnel 193.

[0105] When the mining and crushing unit 7 returns to the main mining tunnel 21, it adjusts its body to mine the other side of the coal seam 1, performing a quarter-elliptical motion at a certain angle along the fifth bifurcated mining tunnel 195. When it reaches the apex of the quarter-ellipse, the mining and crushing unit 7 rotates 90° to the right, turns its body around, and mines backward for a certain distance. Then, the mining and crushing unit 7 rotates another 90° to the right and returns to the main mining tunnel 21 along the sixth bifurcated mining tunnel 196 next to the fifth bifurcated mining tunnel 195. Then, the mining and crushing unit 7 rotates left, turns its body to be parallel to the main mining tunnel 21, and moves to the right at a certain angle along the seventh bifurcated mining tunnel 197 to make a quarter-ellipse motion. When it reaches the apex of the quarter-ellipse, the mining and crushing unit 7 rotates right by 90 degrees, turns its body around, and mines backward for a certain distance. Then, the mining and crushing unit 7 continues to rotate right by 90 degrees and returns to the main mining tunnel 21 along the eighth bifurcated mining tunnel 198 next to the seventh bifurcated mining tunnel 197. After returning to the starting point, the middle and bottom parts of the coal seam 1 are mined vertically downward in sequence.

[0106] Specifically, while the mining and crushing unit 7 is rotating, the equipment continues to perform coal mining. The first branched mining tunnel 191, the second branched mining tunnel 192, the third branched mining tunnel 193, the fourth branched mining tunnel 194, the fifth branched mining tunnel 195, the sixth branched mining tunnel 196, the seventh branched mining tunnel 197, and the eighth branched mining tunnel 198 are collectively referred to as the second mining tunnel 19, and the number is not limited to that shown in the figure; there may be multiple such tunnels.

[0107] This specification uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. An in-situ coal and coalbed methane co-mining system suitable for soft coal seams, characterized in that: It includes a shaft, a vertical shaft lifting unit, an excavation and crushing unit, a secondary crushing unit, a pumping unit, a separation and collection unit and a roof stability monitoring unit. The roof stability monitoring unit is used to monitor the strain information of the roof in real time and issue an early warning. The vertical shaft lifting unit includes a device for conveying equipment into the shaft. The excavation and crushing unit includes a shell, an excavation mechanism, a water jet mechanism, a transmission mechanism, a crushing mechanism and a moving mechanism. The moving mechanism is arranged at the bottom of the shell, the excavation mechanism and the water jet mechanism are arranged at the front end of the shell, and the crushing mechanism is arranged at the bottom of the shell. The rear end of the shell is provided in the shell, and the transmission mechanism is used to transport the coal body cut by the mining mechanism to the crushing mechanism, and the water sprayed by the water jet mechanism is used to convert the coal powder crushed by the crushing mechanism into a fluidized coal-water mixture; a bottom storage tank is provided at the bottom of the shaft, and the secondary crushing unit is provided at the bottom of the shaft and located above the bottom storage tank. The secondary crushing unit is used to perform secondary crushing on the fluidized coal-water mixture, and the pumping unit is used to transfer the coal in the bottom storage tank that has been secondary crushed by the secondary crushing unit The fluidized coal-water mixture is pumped into the separation and collection unit, which is used to separate and collect coal, water and coalbed methane; the mining mechanism includes a cutterhead shell, a cutting cutterhead, a cutterhead drive assembly and a roller cutter group, the cutterhead shell is arranged at the front end of the shell, the cutting cutterhead is rotatably installed at the front end of the cutterhead shell, the cutterhead drive assembly is arranged in the cutterhead shell and is used to drive the cutting cutterhead to rotate, the roller cutter group is provided at the front end of the cutting cutterhead, a plurality of feed holes are provided on the cutting cutterhead, and a plurality of mounting holes; the water jet mechanism includes a water supply component and a plurality of water jet nozzles, each of the mounting holes is provided with a water jet nozzle, the water supply component is arranged on the shell, and is used to supply water to the water jet nozzle; a transmission chamber and a crushing chamber are sequentially arranged in the shell from front to back, the front end of the transmission chamber is connected to the outlet at the rear end of the cutter disc shell, one end of the transmission mechanism is installed in the cutter disc shell, and the other end is installed in the transmission chamber, the crushing mechanism is arranged in the crushing chamber, and the rear end of the shell is provided with a discharge port corresponding to the position of the crushing chamber.

2. The in-situ coal and coalbed methane co-mining system suitable for soft coal seams according to claim 1 is characterized in that: The secondary crushing unit includes a bracket, a crushing bin, a feeding bin, a crushing mechanism and a crushing motor. The bracket is arranged above the bottom storage tank, the crushing bin is arranged on the bracket, the feeding bin is arranged on the top of the crushing bin, the crushing mechanism is arranged in the crushing bin, and the crushing motor is used to provide power to the crushing mechanism.

3. The in-situ coal and coalbed methane co-mining system applicable to soft coal seams according to claim 2 is characterized in that: The crushing mechanism includes an active crushing roller and a driven crushing roller. Both ends of the active crushing roller are rotatably mounted in the crushing bin. Both ends of the driven crushing roller are rotatably mounted in the crushing bin. The driven crushing roller and the active crushing roller are meshed with each other. The crushing motor is used to drive the active crushing roller to rotate.

4. The in-situ coal and coalbed methane co-mining system suitable for soft coal seams according to claim 2 is characterized in that: The feed bin is an inverted cone structure, and the area of ​​the top of the feed bin is larger than the area of ​​the bottom of the shaft.

5. The in-situ coal and coalbed methane co-mining system applicable to soft coal seams according to claim 1 is characterized in that: It also includes a plurality of transfer storage tanks arranged in sequence from bottom to top above the bottom storage tank, and the plurality of transfer storage tanks are all arranged on the same side of the wellbore. The pumping unit includes a bottom pumping mechanism, a top pumping mechanism and an intermediate pumping mechanism. The bottom pumping mechanism is used to pump the fluidized coal-water mixture in the bottom storage tank to the adjacent transfer storage tank, the intermediate pumping mechanism is used to pump the fluidized coal-water mixture in the lower transfer storage tank of the two adjacent transfer storage tanks to the upper transfer storage tank, and the top pumping mechanism is used to pump the fluidized coal-water mixture in the uppermost transfer storage tank to the separation and collection unit.

6. The in-situ coal and coalbed methane co-mining system applicable to soft coal seams according to claim 5 is characterized in that: The bottom pumping mechanism includes a bottom pumping pipe and a bottom particle pump arranged on the bottom pumping pipe, and the two ends of the bottom pumping pipe are respectively connected to the bottom storage tank and the adjacent transfer storage tank; the intermediate pumping mechanism includes an intermediate pumping pipe and an intermediate particle pump arranged on the intermediate pumping pipe, and the two ends of the intermediate pumping pipe are respectively connected to the two adjacent transfer storage tanks; the top pumping mechanism includes a top pumping pipe and a top particle pump arranged on the top pumping pipe, and the two ends of the top pumping pipe are respectively connected to the topmost transfer storage tank and the separation and collection unit.

7. A method for in-situ co-mining of coal and coalbed methane suitable for soft coal seams, characterized in that: The in-situ coal and coalbed methane co-mining system applicable to soft coal seams according to any one of claims 1 to 6 comprises the following steps: Step 1: Based on the surface drilling project, a wellbore is excavated. The depth of the wellbore is greater than the depth of the coal seam. The wellbore is used to build a well lifting system, and a bottom storage tank with a size greater than the diameter of the wellbore is excavated at the bottom of the wellbore to receive the fluidized coal-water mixture flowing back. Step 2: Install a secondary crushing unit above the bottom storage tank, and connect the pumping unit to the bottom storage tank and the separation and collection unit on the ground; Step 3: Before starting coal and coalbed methane mining operations, deploy the roof stability monitoring unit; Step 4: Use the vertical shaft lifting system to transport the mining and crushing unit downward along the shaft to a position close to the top of the coal seam, with the front end of the mining and crushing unit facing the coal seam. After the mining mechanism of the mining and crushing unit contacts the coal seam, it cuts the coal seam along a certain upward coal mining route. The cut coal body is then transported to the crushing mechanism at the rear end of the mining and crushing unit through the transmission mechanism for crushing. The crushed coal powder falls into the mining tunnel. The water jetted by the water jet mechanism at the front end of the mining and crushing unit forms a water flow in the mining tunnel, which converts the coal powder into fluidized state. Driven by the water flow and the inclination of the mining tunnel, the fluidized coal-water mixture continuously flows toward the rear of the mining tunnel until it flows to the shaft and falls. Step 5: The fluidized coal-water mixture falls into the secondary crushing unit for further crushing, and then falls into the bottom storage tank; Step 6: Use the pumping unit to transport the fluidized coal-water mixture in the bottom storage tank from the bottom of the well to the separation and collection unit on the ground for separation and collection.

8. The in-situ coal and coalbed methane co-mining method applicable to soft coal seams according to claim 7, characterized in that: In step 4, for the nearly horizontal coal seam, an upward mining method is adopted. During the mining process, the direction of movement of the mining and crushing unit must form a certain angle with the upward inclination of the coal seam; For inclined coal seams, during mining, the mining and crushing unit moves in the same direction as the coal seam inclination, and mining is carried out along the upward inclination of the coal seam. Mining is carried out using a roundabout mining method. Within the same mining plane, the mining and crushing unit starts to make an elliptical motion starting from the boundary between the shaft and the coal seam. When the mining and crushing unit returns to the shaft, the mining distance is expanded and the elliptical motion is continued. This cycle is repeated several times until it returns to the starting point. For coal seams with a certain thickness, they are mined layer by layer from top to bottom. After a certain range of coal seams close to the roof rock layer are mined, when the mining and crushing unit returns to the starting point, the vertical shaft lifting system is used to lower the mining and crushing unit for a distance, and mining is carried out again using the same roundabout mining method until it approaches the bottom rock layer.

9. The in-situ coal and coalbed methane co-mining method applicable to soft coal seams according to claim 7, characterized in that: In step 4, for the nearly horizontal coal seam, an upward mining method is adopted. During the mining process, the direction of movement of the mining and crushing unit must form a certain angle with the upward inclination of the coal seam; For inclined coal seams, during mining, the mining and crushing unit moves in the same direction as the coal seam inclination, and mining is carried out along the upward inclination of the coal seam. Mining is carried out using a forked mining method. Within the same mining plane, the mining and crushing unit takes the junction of the shaft and the coal seam as the starting point, and the mining and crushing unit mines forward for a certain distance to form a main mining tunnel, and then makes a 1 / 4 elliptical motion to the left of the main mining tunnel. When the mining and crushing unit reaches the apex of the ellipse, the mining and crushing unit begins to rotate 90° to the right and mines forward for a certain distance, and then the mining and crushing unit continues to rotate 90° to the right and makes a 1 / 4 elliptical motion next to the previous mining trajectory; when the mining and crushing unit reaches the main mining tunnel, the mining and crushing unit continues to mine forward for a certain distance, and then makes a 1 / 4 elliptical motion to the left of the main mining tunnel. When the mining and crushing unit reaches the apex of the ellipse, the mining and crushing unit begins to rotate 90° to the right and mines forward for a certain distance, and then the mining and crushing unit continues to rotate 90° to the right and makes a 1 / 4 elliptical motion next to the previous mining trajectory. Make a 1 / 4 elliptical motion, and repeat this cycle several times; after mining forward for a distance along the inclination of the coal seam, return to the main mining tunnel, the mining and crushing unit starts to make a 1 / 4 elliptical motion to the right side of the main mining tunnel, and when the mining and crushing unit reaches the apex of the ellipse, the mining and crushing unit rotates 90° to the right and mines a certain distance backward, and then the mining and crushing unit continues to rotate 90° to the right and makes a 1 / 4 elliptical motion next to the previous mining trajectory, and when it reaches the main mining tunnel, move backward for a certain distance along the main mining tunnel, and the mining and crushing unit makes a 1 / 4 elliptical motion to the right side of the main mining tunnel, and when the mining and crushing unit reaches the apex of the ellipse, the mining and crushing unit rotates 90° to the right and mines a certain distance backward, and then the mining and crushing unit continues to rotate 90° to the right and makes a 1 / 4 elliptical motion next to the previous mining trajectory, and repeat this cycle several times until it reaches the starting position; For coal seams with a certain thickness, they are mined layer by layer from top to bottom. After a certain range of coal seams close to the roof rock layer is mined, when the mining and crushing unit returns to the starting point, the vertical shaft lifting system is used to lower the mining and crushing unit for a distance, and mining is carried out again using the same forked mining method until it approaches the bottom rock layer.

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