A coal mine roadway coal seam tunneling pressure relief device and method

Abstract

The application discloses a coal mine roadway coal seam tunneling pressure relief device and method, and relates to the field of coal mine roadway coal seam tunneling pressure relief devices and methods. The pressure relief device comprises a caterpillar tractor and a drill rod. The drill rod comprises a drill rod body, a first oil cavity extending along the length direction of the drill rod body, and a second oil cavity extending along the radial direction of the drill rod body and being in communication with the first oil cavity. A piston rod is adapted in the second oil cavity, and the piston rod can switch between an extended position outside the second oil cavity and a retracted position inside the second oil cavity. A first grouting pipe is arranged along the extension direction of the first oil cavity, and a second grouting pipe is arranged along the extension direction of the second oil cavity and is in communication with the first grouting pipe. The second grouting pipe is sequentially provided in the second oil cavity and the piston rod. When hydraulic fracturing is needed for the drill hole drilled by the drill rod body, the piston rod is switched from the retracted position to the extended position to form a fracture hole. When pressure relief is needed for hard coal bodies, silent expansion liquid is injected into the fracture hole through the first grouting pipe and the second grouting pipe.

Description

Technical Field

[0001] This invention relates to the field of mining technology, and in particular to a device and method for depressurizing coal seams during coal mine roadway excavation. Background Technology

[0002] With the increasing demand for minerals and the depletion of shallow resources, most mines have entered the stage of deep mining. As mining depth increases, high ground stress characteristics gradually emerge, such as rock bursts, large deformations in soft rock tunnels, rock bursts in hard rock, and rheological phenomena.

[0003] Rockburst, also known as rock burst, is a phenomenon commonly encountered during the mining of hard coal seams. It is caused by the sudden and violent release of accumulated elastic deformation energy within the rock mass under certain conditions, leading to rock bursting and ejection. Rockburst is one of the major safety hazards faced by deep mines, and its prevention and control are crucial tasks in deep coal mining. Rockburst is frequently encountered during the excavation of deep, hard coal seams. Currently, the main method for preventing and controlling rockburst is to use coal seam water injection to relieve pressure on the rock strata. However, during water injection, the small gaps between rock strata result in poor penetration speed and range of pressurized water. Furthermore, after water injection, there is a lack of effective monitoring of rock strata deformation within the water injection borehole, making it impossible to detect pressure changes at the water injection site in a timely manner, thus affecting the effective prevention and control of rockburst.

[0004] Drilling for pressure relief is a commonly used method, but it also has drawbacks such as a large workload, high labor and time consumption, and high costs. On the one hand, it poses a serious threat to the lives of workers; on the other hand, it reduces mining efficiency and limits coal production in coal mines, so it is rarely used. Summary of the Invention

[0005] This solution addresses the problems and needs raised above by proposing a coal seam excavation and decompression device and method for coal mine roadways. Due to the adoption of the following technical features, it can achieve the above-mentioned technical objectives and bring about several other technical effects.

[0006] One object of the present invention is to provide a coal seam excavation and pressure relief device for coal mine roadways, comprising: a tracked tractor and a drill pipe.

[0007] The drill pipe includes:

[0008] Drill pipe body;

[0009] A first oil cavity extending along the length of the drill pipe body and a second oil cavity extending along the radial direction of the drill pipe body and communicating with the first oil cavity are provided; wherein, a piston rod is adapted to be installed in the second oil cavity, and the piston rod can switch between an extended position extending out of the second oil cavity and a retracted position retracted in the second oil cavity;

[0010] A first grouting pipe is arranged along the extension direction of the first oil cavity and a second grouting pipe is arranged along the extension direction of the second oil cavity and connected to the first grouting pipe, wherein the first grouting pipe and the second grouting pipe are not connected to the first oil cavity and the second oil cavity, and the second grouting pipe passes through the second oil cavity and the piston rod in sequence.

[0011] Specifically, when it is necessary to fracturing the borehole drilled by the drill rod body, the piston rod switches from the contracted position to the extended position to form a fracturing hole; when it is necessary to depressurize the hard coal body, the silent expansion fluid is injected into the fracturing hole in sequence through the first grouting pipe and the second grouting pipe.

[0012] In one example of the present invention, the second oil chamber includes a plurality of chambers and is arranged in an array along the circumferential and length directions of the drill pipe body; wherein, the piston rod corresponds one-to-one with the second oil chamber.

[0013] In one example of the present invention, the second grouting pipe includes:

[0014] Grouting pipe body;

[0015] A grouting channel is opened along the extension direction of the piston rod;

[0016] One end of the grouting pipe is connected to the first grouting pipe, and the other end is connected to the grouting channel; the grouting pipe is a flexible telescopic component, such that the sum of the maximum lengths of the grouting pipe and the grouting channel is greater than the length of the second oil cavity.

[0017] In one example of the present invention, the piston rod is further provided with an end cap at the end opposite to the first grouting pipe. The end cap is movable between an open position (opening the grouting channel) and a closed position (closing the grouting channel). When the end cap is in the open position, the piston rod injects silent expansion fluid into the fracturing hole. When the end cap is in the closed position, the piston rod is located in the second oil chamber or fracturing the borehole.

[0018] In one example of the invention, one end of the end cap is pivotally connected to the piston rod, and the other end of the end cap is connected to one end of an elastic element, and the other end of the elastic element is connected to the piston rod, so as to achieve an elastic force that can return to the closed position when the end cap is in the open position.

[0019] In one example of the present invention, the end caps include a plurality of end caps, one end of which is arranged sequentially along the circumferential direction of the piston rod and is hinged to the piston rod. The other ends of the plurality of end caps are sequentially joined together and abutted under the action of the elastic member to close the grouting channel.

[0020] In one example of the invention, the piston rod includes:

[0021] A plug body is movably connected within the second oil cavity, dividing the second oil cavity into a first chamber and a second chamber, wherein the first chamber is connected to the first oil cavity;

[0022] A rod body is located in the second chamber and extends from the plug body in a direction away from the plug body to form a first end and a second end opposite to each other. The first end is fixedly connected to the plug body, and the second end is connected to the end cap. The grouting channel is not connected to the second chamber.

[0023] Another object of the present invention is to provide a depressurization method for a coal seam excavation depressurization device in a coal mine roadway as described in any of the above claims, comprising the following steps:

[0024] S10: Move the tracked tractor to the facing position, and drive the drill rod to drill the borehole.

[0025] S20: Hydraulic oil is pumped into the first oil chamber, and through the second oil chamber, it pushes the piston rod from the retracted position to the extended position, and the piston rod forms a fracture hole on the borehole wall;

[0026] S30: Pump silent expansion fluid into the first grouting pipe. The silent expansion fluid flows through the second grouting pipe and is injected into the fracture hole to complete the pressure relief and coal crushing.

[0027] S40: Repeat steps S10 to S30 to achieve pressure relief and coal crushing in other drilling locations.

[0028] In one example of the present invention, step S30, while pumping silent expansion fluid into the first grouting pipe, also includes:

[0029] Hydraulic oil is injected into the second oil chamber, pushing the piston rod from the extended position to the retracted position to ensure sufficient injection of silent expansion fluid.

[0030] In one example of the present invention, in step S30, the silent expansion liquid is formed by adding an appropriate amount of water to the silent expansion agent based on changes in coal wall hardness and air temperature, and stirring. After stirring, the silent expansion liquid needs to be injected into the fracturing pores within 5-10 minutes.

[0031] The preferred embodiments of the invention will be described in more detail below with reference to the accompanying drawings, so as to facilitate an understanding of the features and advantages of the invention. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention will be briefly described below. The drawings are merely illustrative of some embodiments of the present invention and are not intended to limit the scope of the present invention to all embodiments.

[0033] Figure 1 This is a schematic diagram of the pressure relief device in a coal seam according to an embodiment of the present invention;

[0034] Figure 2 This is a positive effect diagram of the depressurization device according to an embodiment of the present invention after depressurization is completed in the coal seam;

[0035] Figure 3 This is a lateral view of the depressurization device according to an embodiment of the present invention after depressurization is completed in the coal seam.

[0036] Figure 4 This is a schematic diagram of the drill pipe structure according to an embodiment of the present invention;

[0037] Figure 5 for Figure 4 Sectional view along line AA;

[0038] Figure 6 This is a schematic diagram of the hydraulic circuit structure of a drill pipe according to an embodiment of the present invention;

[0039] Figure 7 This is a schematic diagram of the structure of the second oil cavity according to an embodiment of the present invention;

[0040] Figure 8 This is a schematic diagram of the connection structure (tension spring) of the end cap according to one embodiment of the present invention;

[0041] Figure 9 This is a schematic diagram of the connection structure (compression spring) of the end cap according to another embodiment of the present invention.

[0042] List of reference numerals in the attached diagram:

[0043] 1000 pressure relief device;

[0044] 500mm for tunnel floor slab;

[0045] Drilling zone 400;

[0046] Drill hole 410;

[0047] Fragmentation zone 420;

[0048] 300mm for tunnel roof;

[0049] Drill pipe 200;

[0050] Drill pipe body 210;

[0051] First oil chamber 220;

[0052] Second oil chamber 230;

[0053] First chamber 231;

[0054] Second chamber 232;

[0055] Partition 233;

[0056] Protective cavity 234;

[0057] Piston rod 240;

[0058] Plug 241;

[0059] Rod 242;

[0060] Grouting pipe body 243;

[0061] Grouting channel 244;

[0062] Support plate 245;

[0063] First grouting pipe 250;

[0064] Second grouting pipe 260;

[0065] End cap 270;

[0066] Elastic component 271;

[0067] Oil pump 280;

[0068] Pipeline 290;

[0069] 100 tracked tractors;

[0070] Length direction X;

[0071] Radial direction Y;

[0072] The circumferential direction is Z. Detailed Implementation

[0073] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0074] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, “an” or “a” and similar terms do not necessarily indicate a quantity limitation. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships; these relative positional relationships may change accordingly when the absolute position of the described object changes.

[0075] It should be noted that the coal seam consists of the roadway roof 300, the borehole area 400, and the roadway floor 500 from top to bottom. The pressure relief device 1000 is located in the borehole area 400 and fracturing needs to be completed in the borehole area 400.

[0076] According to a first aspect of the present invention, a coal seam excavation and pressure relief device 1000 for coal mine roadways is provided, such as... Figures 1 to 6 As shown, it includes: a tracked tractor 100 and a drill pipe 200.

[0077] The drill pipe 200 includes:

[0078] Drill pipe body 210;

[0079] A first oil cavity 220 extending along the length direction X of the drill pipe body 210 and a second oil cavity 230 extending along the radial direction Y of the drill pipe body 210 and communicating with the first oil cavity 220 are provided; wherein, a piston rod 240 is adapted to be provided in the second oil cavity 230, and the piston rod 240 is capable of switching between an extended position extending out of the second oil cavity 230 and a retracted position retracted in the second oil cavity 230;

[0080] A first grouting pipe 250 is arranged along the extension direction (i.e., the length direction X) of the first oil cavity 220 and a second grouting pipe 260 is arranged along the extension direction of the second oil cavity 230 and connected to the first grouting pipe 250. The first grouting pipe 250 and the second grouting pipe 260 are not connected to the first oil cavity 220 and the second oil cavity 230, and the second grouting pipe 260 passes through the second oil cavity 230 and the piston rod 240 in sequence.

[0081] When it is necessary to fracturing the borehole 410 drilled by the drill rod body 210, the piston rod 240 switches from the contracted position to the extended position to form a fracturing hole; when it is necessary to depressurize the hard coal body, the silent expansion fluid is injected into the fracturing hole through the first grouting pipe 250 and the second grouting pipe 260 in sequence.

[0082] The working process of the 1000 coal seam excavation and pressure relief device in a coal mine roadway is as follows:

[0083] First, the tracked tractor 100 is moved to the facing position, and the tracked tractor 100 drives the drill rod 200 to drill the borehole 410. Then, hydraulic oil is pumped into the first oil chamber 220, which passes through the second oil chamber 230 and pushes the piston rod 240 from the retracted position to the extended position, forming a fracture hole on the wall of the borehole 410 by the piston rod 240. Next, silent expansion fluid is pumped into the first grouting pipe 250, and the silent expansion fluid flows through the second grouting pipe 260 and is injected into the fracture hole. Finally, the above steps are repeated to achieve the depressurization of the boreholes 410 in other positions. After the silent expansion fluid takes effect, the hard medium will be squeezed and broken.

[0084] This invention, based on the traditional coal roadway excavation face borehole 410 pressure relief method, achieves advanced coal crushing at the face using a silent expanding agent. It is simple and easy to operate. The use of a tracked tractor 100 and grouting pipes greatly saves manpower and time costs, and the hollow inner diameter of the drill rod 200 improves the efficiency of subsequent filling with grout. This invention transfers localized high ground stress to the surrounding or deeper rock, improving the stress distribution of the rock mass and reducing stress in the excavation area. It achieves full-section, long-depth coal crushing and pressure relief in the roadway using a relatively small number of boreholes; reduces later-stage roadway deformation and lowers later-stage maintenance costs; and simultaneously, it can achieve both borehole 410 pressure relief and coal crushing on a single set of equipment, improving mining efficiency and saving time and labor costs.

[0085] In one example of the present invention, such as Figure 5 and Figure 6 As shown, the second oil chamber 230 includes multiple chambers and is arranged in an array along the circumferential direction Z and the length direction X of the drill pipe body 210; wherein, the piston rod 240 corresponds one-to-one with the second oil chamber 230;

[0086] For example, four second oil chambers 230 are spaced apart along the circumferential direction Z of the drill pipe body 210 to form a group of second oil chambers 230, and multiple groups of second oil chambers 230 are spaced apart along the length direction X of the drill pipe body 210 (the specific number depends on the length of the drill pipe body 210 and the fracturing requirements). By setting multiple second oil chambers 230, when it is necessary to fracturing the borehole 410 drilled by the drill pipe body 210, multiple piston rods 240 can be extended simultaneously in the circumferential direction Z of the drill pipe body 210. The fracturing of the borehole 410 can be achieved by multiple piston rods 240, and the fracturing effect is more uniform.

[0087] It should be noted that, as Figure 6 As shown, the piston rod 240 is located in the second oil chamber 230, dividing the second oil chamber 230 into a first chamber 231 and a second chamber 232. The second chamber 232 is connected to the oil pump 280, the first chamber 231 is connected to the first oil chamber 220, and the first chamber 231 is also connected to the oil pump 280.

[0088] For example, preferably, the second oil chamber 230 includes four chambers, and the second chamber 232 of each two adjacent second oil chambers 230 is connected to the oil pump 280 through an oil pipe 290, and the first oil chamber 220 is connected to the oil pump through an oil pipe 290.

[0089] In one example of the present invention, such as Figure 7 As shown, the second grouting pipe 260 includes:

[0090] Grouting pipe body 243;

[0091] Grouting channel 244 is opened along the extending direction of the piston rod 240;

[0092] One end of the grouting pipe body 243 is connected to the first grouting pipe 250, and the other end is connected to the grouting channel 244; wherein the grouting pipe body 243 is a flexible telescopic component, such that the sum of the maximum lengths of the grouting pipe body 243 and the grouting channel 244 is greater than the length of the second oil cavity 230;

[0093] In other words, when fracturing is required in the borehole 410 drilled by the drill pipe body 210, hydraulic oil is pumped into the first oil chamber 220 by the oil pump 280. The hydraulic oil pushes the piston rod 240 from the retracted position to the extended position through the second oil chamber 230 to form a fracturing hole on the wall of the borehole 410. During this process, the hydraulic oil in the second chamber 232 flows back to the oil pump 280. Because the grouting pipe 243 is a flexible telescopic component, it can adapt to the distance changes caused by the movement of the piston rod 240 away from the first oil chamber 220, and the grouting pipe 243 has sufficient length. When it is necessary to depressurize the hard coal body, silent expansion fluid is pumped into the first grouting pipe 250 by the high-pressure pump. The silent expansion fluid is injected into the fracturing hole through the first grouting pipe 250 and the second grouting pipe 260 in sequence. The second grouting pipe 260 can isolate the silent expansion fluid from the hydraulic oil and simultaneously realize the functions of fracturing and injecting silent expansion fluid.

[0094] Understandably, when it is necessary to restore the drill pipe 200 to its initial position, the oil pump 280 pumps hydraulic oil into the second chamber 232. At this time, the hydraulic oil in the second chamber 232 will push the piston rod 240 from the extended position to the retracted position. During this process, the hydraulic oil located in the first chamber 231 or the first oil chamber 220 will flow back to the oil pump 280.

[0095] It should be noted that, in order to ensure that the piston rod 240 and the second oil chamber 230 work independently, a partition 233 is provided at one end of the second chamber 232 near the piston rod 240 with a height of 270, and the piston rod 240 passes through the partition 233. A protective cavity 234 is formed on the side of the partition 233 away from the second chamber 232. The second chamber 232 and the protective cavity 234 are sealed and isolated from each other (that is, during the extension and retraction of the piston rod 240, the connecting hole on the partition 233 that matches the piston rod 240 is always sealed and connected to the piston rod 240). The inner diameter of the protective cavity 234 is smaller than the inner diameter of the second chamber 232, but slightly larger than the outer diameter of the piston rod 240. When the piston rod 240 is in the retracted position, the end cap 270 side of the piston rod 240 is located inside the protective cavity 234.

[0096] In one example of the present invention, such as Figure 8 As shown, the piston rod 240 is also equipped with an end cap 270 at the end opposite to the first grouting pipe 250. The end cap 270 can switch between an open position and a closed position of the grouting channel 244. When the end cap 270 is in the open position, the piston rod 240 injects silent expansion fluid into the fracturing hole. When the end cap 270 is in the closed position, the piston rod 240 is located in the second oil chamber 230 or performs fracturing on the borehole 410.

[0097] To prevent coal and rock from entering the grouting channel 244 of the piston rod 240 during fracturing, an end cap 270 is provided on the grouting channel 244 of the piston rod 240. When the end cap 270 is in the open position, the piston rod 240 injects silent expansion fluid into the fracturing hole. When the end cap 270 is in the closed position, the piston rod 240 is located in the second oil chamber 230 or performs fracturing on the borehole 410. At the same time, the end cap 270 also protects the piston.

[0098] In one example of the present invention, one end of the end cap 270 is pivotally connected to the piston rod 240, and the other end of the end cap 270 is connected to one end of the elastic member 271, and the other end of the elastic member 271 is connected to the piston rod 240, so as to achieve an elastic force that can return to the closed position when the end cap 270 is in the open position.

[0099] For example, such as Figure 8 As shown, the elastic element 271 is a tension spring, and the end cap 270 is located outside the grouting channel 244. One end of the tension spring is connected to the inner wall of the end cap 271, and the other end of the tension spring is connected to the piston rod 240. When the piston rod 240 fracturing the borehole 410, the end cap 270, under the action of the tension spring, closes the grouting channel 244 on the piston rod 240, and the end of the piston rod 240 with the end cap 270 switches from the contracted position to the extended position to fracturing the coal and rock. When the piston rod 240 depressurizes the hard coal body, the silent expansion fluid is sequentially injected through the first grouting pipe 250, the second grouting pipe 260, and the grouting channel 244, and the end cap 270 is switched from the closed position to the open position, thereby injecting the silent expansion fluid into the fracture hole. During this process, the tension spring generates an elastic force that pulls the end cap 270 from the open position to the closed position. After the silent expansion fluid is injected, the end cap 270 returns to the initial closed position under the action of the elastic force.

[0100] Preferably, when the elastic element 271 is a tension spring, in order to facilitate the connection of the elastic element 271, a support plate 245 is provided on the side of the grouting channel 244 near the end cap 270. The support plate 245 extends from the inner wall of the grouting channel 244 in its radial direction toward the direction away from the inner wall, thereby facilitating the connection of the elastic element.

[0101] For example, such as Figure 9As shown, the elastic element 271 is a compression spring. One end of the end cap 270 is pivotally connected to the grouting channel 244, and the other end of the end cap 270 is located outside the grouting channel. One end of the compression spring is fixedly connected to the outer wall of the end cap 271, and the other end of the compression spring is fixedly connected to the inner wall of the grouting channel 244. When the piston rod 240 fracturing the borehole 410, the end cap 270, under the action of the compression spring, closes the grouting channel 244 on the piston rod 240, and the end of the piston rod 240 with the end cap 270 cuts from the contracted position. The piston rod 240 is moved to the extended position to perform fracturing on the coal and rock. When the piston rod 240 depressurizes the hard coal body, the silent expansion fluid is sequentially injected through the first grouting pipe 250, the second grouting pipe 260, and the grouting channel 244, and the end cap 270 is switched from the closed position to the open position, thereby injecting the silent expansion fluid into the fracturing hole. During this process, the compression spring generates an elastic force that compresses the end cap 270 from the open position to the closed position. After the silent expansion fluid is injected, the end cap 270 returns to the initial closed position under the action of the elastic force.

[0102] By setting the elastic element 271, the end cap 270 can be flexibly switched between the open and closed positions.

[0103] It should be noted that the elastic force of the elastic element 271 is strong enough to ensure the sealing of the grouting channel 244 when the end cap 270 is in the closed position; when pressure relief is required, the pressure of the silent expansion liquid is greater than the elastic force of the elastic element 271, so that the end cap 270 can be opened; for example, the first grouting pipe 250 is connected to the high-pressure pump body (not shown in the figure), so that the silent expansion liquid can be injected and pressurized.

[0104] Of course, the present invention is not limited to this. A valve (e.g., a one-way valve) can also be provided on the piston rod 240. By providing the valve, the opening and closing of the grouting channel 244 of the piston rod 240 can be controlled. The working principle is similar to the structure described above, and will not be repeated here.

[0105] In one example of the present invention, the end cap 270 includes a plurality of end caps 270, one end of the plurality of end caps 270 is arranged sequentially along the circumferential direction Z of the piston rod 240 and is hinged to the piston rod 240, and the other ends of the plurality of end caps 270 are sequentially spliced ​​together and abutted under the action of the elastic member 271 to close the grouting channel 244.

[0106] For example, there are two end caps 270, which are symmetrically arranged at one end of the grouting channel 244 away from the first grouting pipe 250. One end of each end cap 270 is hinged to the port of the grouting channel 244 of the piston rod 240. The other end and side of each end cap 270 are mutually abutted and joined together under the action of the elastic member 271. They can be opened to the open position when the silent expansion liquid is injected, overcoming the elastic force of the elastic member 271, and return to the closed position when the silent expansion liquid is stopped.

[0107] In one example of the present invention, such as Figure 7 As shown, the piston rod 240 includes:

[0108] The plug body 241 is movably connected to the second oil cavity 230 and divides the second oil cavity 230 into a first chamber 231 and a second chamber 232, wherein the first chamber 231 is connected to the first oil cavity 220;

[0109] The rod body 242 is located in the second chamber 232 and extends from the plug body 241 in a direction away from the plug body 241 to form a first end and a second end opposite to each other. The first end is fixedly connected to the plug body 241, and the second end is connected to the end cap 270; wherein, the grouting channel 244 is not connected to the second chamber 232.

[0110] When fracturing is required in the borehole 410 drilled by the drill pipe body 210, the oil pump 280 pushes the piston rod 240 from the retracted position to the extended position through the first oil chamber 220 and the first chamber 231 to form a fracturing hole on the borehole wall. During this process, the hydraulic oil in the second chamber 232 flows back to the oil pump 280. When it is necessary to depressurize the hard coal body, the high-pressure pump injects silent expansion fluid into the fracturing hole through the first grouting pipe 250 and the second grouting pipe 260 in sequence. At the same time, in order to ensure sufficient injection of silent expansion fluid, the oil pump 280 injects hydraulic oil into the second chamber 232 of the second oil chamber 230, pushing the piston rod 240 from the extended position to the retracted position. At the same time, the hydraulic oil in the first oil chamber 220 flows back to the oil pump 280.

[0111] According to a second aspect of the present invention, a method for depressurizing a coal seam tunneling depressurization device 1000 as described in any of the above claims includes the following steps:

[0112] S10: Move the tracked tractor 100 to the facing position, and drive the drill rod to drill the borehole 410 by the tracked tractor 100;

[0113] S20: Hydraulic oil is pumped into the first oil chamber 220, and through the second oil chamber 230, it pushes the piston rod 240 to move from the retracted position to the extended position, and the piston rod 240 forms a fracture hole on the wall of the borehole 410.

[0114] S30: Pump silent expansion fluid into the first grouting pipe 250. The silent expansion fluid flows through the second grouting pipe 260 and is injected into the fracture hole to complete the pressure relief and coal crushing.

[0115] S40: Repeat steps S10 to S30 to achieve pressure relief and coal crushing in boreholes 410 at other locations;

[0116] Specifically, when it is necessary to fracturing the borehole 410 drilled by the drill pipe body 210, the oil pump 280 pushes the piston rod 240 from the retracted position to the extended position through the first oil chamber 220 and the first chamber 231 to form a fracturing hole on the borehole wall. During this process, the hydraulic oil in the second chamber 232 flows back to the oil pump 280. When it is necessary to depressurize the hard coal body, the high-pressure pump injects silent expansion fluid into the fracturing hole through the first grouting pipe 250 and the second grouting pipe 260 in sequence. At the same time, in order to ensure sufficient injection of silent expansion fluid, the oil pump 280 injects hydraulic oil into the second chamber 232 of the second oil chamber 230, pushing the piston rod 240 from the extended position to the retracted position. At the same time, the hydraulic oil in the first oil chamber 220 flows back to the oil pump 280.

[0117] This method, based on the traditional coal roadway excavation face borehole 410 pressure relief, achieves advanced coal crushing at the face using a silent expanding agent. It is simple and easy to operate. The use of a tracked tractor 100 and grouting pipes greatly saves manpower and time costs, and the hollow inner diameter of the drill rod 200 improves the efficiency of subsequent filling with grout. This invention transfers localized high ground stress to the surrounding or deeper rock, improving the stress distribution of the rock mass and reducing stress in the excavation area. It achieves full-section, long-depth coal crushing and pressure relief in the roadway using a relatively small number of boreholes; reduces later-stage roadway deformation and lowers later-stage maintenance costs; and simultaneously, it can achieve both borehole 410 pressure relief and coal crushing on a single set of equipment, improving efficiency and saving time and labor costs.

[0118] In one example of the present invention, step S30, while pumping silent expansion fluid into the first grouting pipe 250, also includes:

[0119] Hydraulic oil is injected into the second oil chamber 230, pushing the piston rod 240 from the extended position to the retracted position to ensure sufficient injection of silent expansion fluid;

[0120] By retracting the piston rod 240 in the extended position, a certain space can be created in the fracture hole, thereby facilitating the injection of silent expansion fluid.

[0121] In one example of the present invention, in step S30, the silent expansion liquid is formed by adding an appropriate amount of water to the silent expansion agent based on the changes in coal wall hardness and temperature, and the silent expansion liquid needs to be injected into the fracturing pore within 5 min to 10 min after the stirring is completed.

[0122] Silent expanding agent is added to an appropriate amount of water and stirred to form silent expanding liquid. The amount of water added is adjusted according to the temperature and the type of silent expanding agent, and can also be adjusted according to changes in coal wall hardness. After the silent expanding agent is stirred evenly, it is injected into the fracturing hole inside the large borehole 410 through the hollow of a specially designed drill rod 200 via a grouting pipe. At the same time, the piston rod 240 is slowly contracted during grouting to ensure sufficient injection of silent expanding liquid and further enhance the fracturing effect.

[0123] The foregoing description, with reference to preferred embodiments, details exemplary implementations of the coal mine roadway coal seam excavation and decompression device 1000 and method proposed in this invention. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the concept of this invention, and various combinations can be made to the various technical features and structures proposed in this invention without exceeding the protection scope of this invention, which is determined by the appended claims.

Claims

1. A coal seam excavation and pressure relief device for coal mine roadways, comprising: The tracked tractor (100) and drill pipe 200 are characterized in that, The drill pipe (200) includes: Drill pipe body (210); A first oil cavity (220) extending along the length direction (X) of the drill pipe body (210) and a second oil cavity (230) extending along the radial direction (Y) of the drill pipe body (210) and communicating with the first oil cavity (220); wherein, a piston rod (240) is adapted to be installed in the second oil cavity (230), and the piston rod (240) is capable of switching between an extended position extending out of the second oil cavity (230) and a retracted position retracted in the second oil cavity (230); A first grouting pipe (250) is arranged along the extension direction of the first oil cavity (220), and a second grouting pipe (260) is arranged along the extension direction of the second oil cavity (230) and connected to the first grouting pipe (250). The first grouting pipe (250) and the second grouting pipe (260) are not connected to the first oil cavity (220) and the second oil cavity (230), and the second grouting pipe (260) passes through the second oil cavity (230) and the piston rod (240) in sequence. The second grouting pipe (260) includes: a grouting pipe body (243); and a grouting channel (244) extending along the extension direction of the piston rod (240). One end of the grouting pipe body (243) is connected to the first grouting pipe (250), and the other end is connected to the grouting channel (244). 44) Connected; wherein, the grouting pipe body (243) is a flexible telescopic component, such that the sum of the maximum lengths of the grouting pipe body (243) and the grouting channel (244) is greater than the length of the second oil chamber (230); the piston rod (240) is also provided with an end cap (270) at the end opposite to the first grouting pipe (250), the end cap (270) can switch between the open position of opening the grouting channel (244) and the closed position of closing the grouting channel (244); wherein, when the end cap (270) is in the open position, the piston rod (240) injects silent expansion fluid into the fracturing hole; when the end cap (270) is in the closed position, the piston rod (240) is located in the second oil chamber (230) or fracturing the borehole (410); When it is necessary to fracturing the borehole (410) drilled by the drill rod body (210), the piston rod (240) switches from the contracted position to the extended position to form a fracturing hole; when it is necessary to depressurize the hard coal body, the silent expansion fluid is injected into the fracturing hole through the first grouting pipe (250) and the second grouting pipe (260) in sequence.

2. The coal seam excavation and pressure relief device for coal mine roadways according to claim 1, characterized in that, The second oil chamber (230) includes multiple chambers and is arranged in an array along the circumferential direction (Z) and length direction (X) of the drill pipe body (210); wherein, the piston rod (240) corresponds one-to-one with the second oil chamber (230).

3. The coal seam excavation and pressure relief device for coal mine roadways according to claim 1, characterized in that, One end of the end cap (270) is pivotally connected to the piston rod (240), and the other end of the end cap (270) is connected to one end of the elastic element (271), and the other end of the elastic element (271) is connected to the piston rod (240) so as to achieve an elastic force that can return to the closed position when the end cap (270) is in the open position.

4. The coal seam excavation and pressure relief device for coal mine roadways according to claim 3, characterized in that, The end caps (270) include a plurality of them. One end of the plurality of end caps (270) is arranged sequentially along the circumferential direction (Z) of the piston rod (240) and is hinged to the piston rod (240). The other ends of the plurality of end caps (270) are sequentially spliced ​​together and abutted under the action of the elastic member (271) to close the grouting channel (244).

5. The coal seam excavation and pressure relief device for coal mine roadways according to claim 1, characterized in that, The piston rod (240) includes: A plug (241) is movably connected to the second oil cavity (230) and divides the second oil cavity (230) into a first chamber (231) and a second chamber (232), wherein the first chamber (231) is connected to the first oil cavity (220); The rod (242) is located in the second chamber (232) and extends from the plug (241) in a direction away from the plug (241) to form a first end and a second end opposite to each other. The first end is fixedly connected to the plug (241), and the second end is connected to the end cap (270). The grouting channel (244) is not connected to the second chamber (232).

6. A method for depressurizing a coal seam excavation depressurization device for coal mine roadways as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S10: Move the tracked tractor (100) to the facing position, and drive the drill rod (200) to drill the borehole (410). S20: Hydraulic oil is pumped into the first oil chamber (220), and through the second oil chamber (230), the piston rod (240) is pushed to move from the retracted position to the extended position, and the piston rod (240) forms a fracture hole on the wall of the borehole (410); S30: Pump silent expansion fluid into the first grouting pipe (250), and the silent expansion fluid flows through the second grouting pipe (260) and is injected into the fracture hole to complete the pressure relief and coal crushing; S40: Repeat steps S10 to S30 to achieve decompression and coal crushing of boreholes (410) at other locations.

7. The depressurization method of the coal seam excavation depressurization device in coal mine roadways according to claim 6, characterized in that, In step S30, the silent expansion fluid is pumped into the first grouting pipe (250) simultaneously with: Hydraulic oil is injected into the second oil chamber (230) to push the piston rod (240) from the extended position to the retracted position, so as to ensure the full injection of silent expansion fluid.

8. The depressurization method of the coal seam excavation depressurization device in coal mine roadways according to claim 6, characterized in that, In step S30, the silent expansion liquid is formed by adding an appropriate amount of water to the silent expansion agent based on the changes in coal wall hardness and temperature, and the silent expansion liquid needs to be injected into the fracturing pore within 5-10 minutes after the stirring is completed.

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