Rock breaking device and rock breaking method combining liquid nitrogen jet flow and particle impact

Abstract

The invention belongs to the technical field of rock stratum drilling, and particularly relates to a liquid nitrogen jet flow and particle impact combined rock breaking device and method. The rock breaking device comprises a liquid nitrogen jet fracturing system and a particle impact system; the liquid nitrogen injection fracturing system at least comprises a liquid supply assembly and a hollow drill rod, the liquid supply assembly is used for providing pressurized liquid nitrogen for the hollow drill rod, a plurality of liquid nitrogen nozzles are arranged in the circumferential direction of the hollow drill rod, and the hollow drill rod is used for injecting the liquid nitrogen into the rock body through the liquid nitrogen nozzles in drill holes in the rock wall; the particle impact system comprises a particle acceleration assembly and a particle nozzle, and the particle acceleration assembly is used for accelerating particles and spraying the particles onto the rock wall near the first feeding hole through the particle nozzle. According to the rock breaking device, the problem that a traditional mechanical rock breaking tool is abraded is solved; and moreover, the rock breaking device can realize the whole-process hydration-free operation, and basically no residue is left after the liquid nitrogen is vaporized, so that the rock breaking construction process is safer and more environment-friendly.

Description

Technical Field

[0001] The invention belongs to the technical field of rock drilling, and specifically relates to a rock breaking device and a rock breaking method using a liquid nitrogen jet combined with particle impact. Background Art

[0002] In the process of coal mining and underground excavation, it is inevitable to face hard rock. Commonly used rock breaking methods include drilling and blasting and mechanical rock breaking. The drilling and blasting method refers to the method of pre-drilling blastholes, filling the holes with explosives, and detonating the explosives. The mechanical rock breaking method refers to the method of using mechanical rock breaking devices to apply external concentrated loads to the rock mass to break the rock mass. The mechanical rock breaking method has the advantages of being safer and more efficient, and has now become the mainstream method for underground engineering construction.

[0003] However, traditional mechanical rock breaking methods will cause the tool to wear faster when breaking hard rock, which will not only directly affect the construction efficiency, but also easily cause engineering accidents such as excavation face instability and coal rock collapse when replacing the tool. How to reduce tool wear and achieve better rock breaking effect is the bottleneck problem in achieving efficient rock drilling.

[0004] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Invention content

[0005] The purpose of the invention is to provide a rock breaking device and a rock breaking method combining liquid nitrogen jet and particle impact, so as to at least solve the above-mentioned problems existing in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A liquid nitrogen jet combined with particle impact rock breaking device, the rock breaking device comprising a liquid nitrogen jet fracturing system and a particle impact system;

[0008] The liquid nitrogen jet fracturing system comprises at least a liquid supply assembly and a hollow drill rod, wherein the liquid supply assembly is used to provide pressurized liquid nitrogen to the hollow drill rod, a plurality of liquid nitrogen nozzles are arranged on the circumference of the hollow drill rod, and the hollow drill rod is used to spray liquid nitrogen into the rock body through the liquid nitrogen nozzles in the borehole on the rock wall;

[0009] The particle impact system comprises a particle acceleration component and a particle nozzle. The particle acceleration component is used to accelerate particles and spray the particles onto a rock wall near the borehole through the particle nozzle.

[0010] In the rock breaking device of liquid nitrogen jet combined with particle impact as described above, preferably, the front end of the hollow drill rod is connected to a drill bit, a bridge plug and a packer are arranged at intervals on the hollow drill rod behind the drill bit, and the liquid nitrogen nozzle is located on the hollow drill rod between the bridge plug and the packer.

[0011] As described above, in the rock breaking device of liquid nitrogen jet combined with particle impact, preferably, the liquid supply component includes at least a self-pressurized liquid nitrogen storage tank and a liquid nitrogen buffer tank, the self-pressurized liquid nitrogen storage tank and the liquid nitrogen buffer tank are connected by a first pipeline, the self-pressurized liquid nitrogen storage tank is used to charge liquid nitrogen into the hydraulic buffer tank, and a first solenoid valve is arranged on the first pipeline.

[0012] The rock breaking device of liquid nitrogen jet combined with particle impact as described above, preferably, the liquid supply assembly further comprises a liquid pump, the liquid pump is arranged downstream of the buffer tank, and the liquid pump is used to pressurize the liquid nitrogen in the liquid nitrogen buffer tank into a liquid nitrogen jet;

[0013] The liquid inlet of the liquid pump is connected to the liquid nitrogen buffer tank through a second pipeline, and a second solenoid valve is arranged on the second pipeline.

[0014] In the rock breaking device of liquid nitrogen jet combined with particle impact as described above, preferably, the driving source of the liquid pump includes a frequency conversion control box, a motor and a transmission box, the output end of the motor is transmission-connected to the input end of the transmission box, and the output end of the transmission box is transmission-connected to the input shaft of the liquid pump; the frequency conversion control box is connected to the motor for controlling the rotation speed of the motor.

[0015] In the rock breaking device of liquid nitrogen jet combined with particle impact as described above, preferably, a third pipeline is connected to the liquid outlet of the liquid pump, and a third solenoid valve and a pressure gauge are provided on the third pipeline; the third pipeline is respectively connected to a plurality of hollow drill rods through a branch pipe, so that the liquid pump can simultaneously deliver pressurized liquid nitrogen jets to the plurality of hollow drill rods.

[0016] The rock breaking device of liquid nitrogen jet combined with particle impact as described above, preferably, the particle acceleration assembly comprises a particle acceleration tube, an impact rod, an air compressor and a gas cylinder, and the impact rod is guided and moved in the particle acceleration tube;

[0017] The gas cylinder is connected to the air compressor via a pipeline for supplying gas to the air compressor, and a gas cylinder valve is provided on the pipeline between the gas cylinder and the air compressor;

[0018] The air compressor is connected to the particle acceleration tube through a pipeline and is used to provide compressed gas to the particle acceleration tube.

[0019] The rock breaking device of liquid nitrogen jet combined with particle impact as described above, preferably, the particle acceleration assembly further comprises a particle filling mechanism, the particle filling mechanism at least comprises a sleeve and an inner tube, the inner tube is arranged inside the sleeve, the inner tube is connected to one side of the particle acceleration tube, and is used to provide particles into the particle acceleration tube;

[0020] One side of the inner tube is connected to a particle bin through a pipeline, and the particle bin is used to replenish particles into the inner tube.

[0021] As described above, the rock breaking device of liquid nitrogen jet combined with particle impact, preferably, a base is provided at the lower part of the casing, the inner tube extends into the base, a bottom plate is provided at the lower part of the inner tube, a guide seal in the inner tube is matched with a pad, a spring is provided between the pad and the bottom plate, and a plurality of particles are supported above the pad;

[0022] The particle filling mechanism further comprises a vacuum pump, a fourth pipeline is arranged between the vacuum pump and the particle acceleration tube, and a fourth solenoid valve is arranged on the fourth pipeline for controlling the resetting of the impact rod;

[0023] A fifth pipeline is arranged between the vacuum pump and the bottom plate, the fifth pipeline passes through the bottom plate and extends into the inner tube, and a fifth solenoid valve is arranged on the fifth pipeline for compressing the spring.

[0024] The present application also provides a rock breaking method using a liquid nitrogen jet combined with particle impact, wherein the rock breaking method uses the above-mentioned rock breaking device using a liquid nitrogen jet combined with particle impact, and the rock breaking method comprises the following steps:

[0025] Step 1, firstly drill a plurality of boreholes on the rock wall, and then insert a plurality of hollow drill rods connected with a fluid supply assembly into each borehole;

[0026] Step 2, opening the first solenoid valve to allow the self-pressurized liquid nitrogen storage tank to deliver a set amount of liquid nitrogen to the liquid nitrogen buffer tank, and then closing the first solenoid valve;

[0027] Step 3, open the second solenoid valve and the third solenoid valve, and turn on the liquid pump. The liquid pump pressurizes the liquid nitrogen in the liquid nitrogen buffer tank into a liquid nitrogen jet, transmits it to the hollow drill pipe, and sprays the liquid nitrogen jet into the rock mass through the liquid nitrogen nozzle on the hollow drill pipe, and continuously sprays liquid nitrogen into the rock mass at a set pressure for a set time;

[0028] Step 4, open the gas cylinder valve, start the air compressor to compress the gas and transmit it to the particle acceleration tube, the impact rod moves at high speed along the particle acceleration tube under the action of high-pressure air to impact the particles, so that the particles are ejected from the particle nozzle at high speed, and the particles are sprayed onto the rock wall between the four boreholes to break the rock mass; open the fourth solenoid valve, and start the vacuum pump to reset the impact rod; then repeat the above process, so that the particles repeatedly impact and break the rock wall;

[0029] Step 5, when the particles in the inner tube are used up, the fifth solenoid valve and the particle valve are opened, and the vacuum pump is started to make the pad press down the spring, and the particles in the particle bin are then added to the inner tube;

[0030] Step 6: Repeat steps 1-5 until the set rock excavation task is completed.

[0031] Beneficial effects:

[0032] In the rock breaking device, high-pressure liquid nitrogen is first injected into the rock wall through a hollow drill rod, so that the liquid nitrogen diffuses around the borehole. Under the action of liquid nitrogen, the rock mass is frozen and cracked, making the rock mass gradually brittle and generating cracks inside. Then, the particles are accelerated to a higher speed through a particle acceleration component, and high-speed particles are shot to the rock wall around the borehole through a particle nozzle, so that the rock mass is broken under the impact of the particles. Due to the weakening effect of liquid nitrogen, the brittleness of the rock mass increases and cracks are generated inside, and the high-speed particles have sufficient impact energy to break the weakened hard rock. The rock breaking device not only gets rid of the problem of wear of traditional mechanical rock breaking tools, but also greatly improves the drilling efficiency. The rock breaking device can realize water-free operation throughout the process, and there is basically no residue after the liquid nitrogen is vaporized, making the rock breaking construction process safer and more environmentally friendly.

[0033] The gas cylinder valve is opened, and the air compressor is started to compress the gas and transmit it to the particle accelerator tube. The impact rod moves at high speed along the particle accelerator tube under the action of high-pressure air to impact the particles, so that the particles are ejected from the particle nozzle at high speed and sprayed onto the rock wall between the four boreholes to break the rock mass; the particles impact the rock wall between the four boreholes, so that the liquid nitrogen jets emitted by multiple hollow drill rods and the particle impact action are coupled with each other as much as possible to achieve a better rock breaking effect.

[0034] The vacuum pump can be used to generate negative pressure in the particle support tube to facilitate the resetting of the impact rod, and can also be used to generate negative pressure in the inner tube to make the pad compress the spring to facilitate the replenishment of particles into the inner tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings constituting part of the present application are used to provide a further understanding of the invention. The exemplary embodiments and descriptions of the invention are used to explain the invention and do not constitute an improper limitation on the invention. Among them:

[0036] Figure 1 A schematic diagram of the structure of a rock breaking device according to an embodiment of the present invention;

[0037] Figure 2 A schematic diagram of the structure of a hollow drill rod according to an embodiment of the present invention;

[0038] Figure 3 A schematic diagram of the structure of a particle filling device according to an embodiment of the present invention;

[0039] Figure 4 A schematic diagram of a drilling working surface is provided for creating an embodiment of the present invention.

[0040] In the figure: 1. Self-pressurized liquid nitrogen storage tank; 2. Inner tank; 3. Outer shell; 4. Boosting valve; 5. Safety valve; 6. Vent valve; 7. First solenoid valve; 8. Liquid nitrogen buffer tank; 9. Second solenoid valve; 10. Liquid pump; 11. Transmission box; 12. Motor; 13. Frequency conversion control box; 14. Pressure gauge; 15. Third solenoid valve; 16. Drilling rig; 17. Hollow drill pipe; 18. Drill bit; 19. Packer; 2 0. Liquid nitrogen nozzle; 21. Bridge plug; 22. Gas cylinder; 23. Gas cylinder valve; 24. Air compressor; 25. Ball valve; 26. Pressure gauge; 27. Particle accelerator; 28. Impact rod; 29. ​​Fourth solenoid valve; 30. Vacuum pump; 31. Particle bin; 32. Particle valve; 33. Casing; 34. Pad; 35. Spring; 36. Inner tube; 37. Base; 38. Fifth solenoid valve; 39. Particle nozzle. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0042] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention. The terms "connected" and "connected" used in the present invention should be understood in a broad sense. For example, they can be fixedly connected or detachably connected; they can be directly connected or indirectly connected through intermediate components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0043] The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0044] According to the specific embodiments of the present invention, Figure 1-4 As shown, the present invention provides a liquid nitrogen jet combined with particle impact rock breaking device, the rock breaking device includes a liquid nitrogen jet fracturing system and a particle impact system;

[0045] The liquid nitrogen jet fracturing system comprises at least a liquid supply assembly and a hollow drill rod 17, wherein the liquid supply assembly is used to supply pressurized liquid nitrogen to the hollow drill rod 17, and a plurality of liquid nitrogen nozzles 20 are arranged on the circumference of the hollow drill rod 17, and the hollow drill rod 17 is used to spray liquid nitrogen into the rock body through the liquid nitrogen nozzles 20 in the borehole on the rock wall;

[0046] The particle impact system includes a particle acceleration component and a particle nozzle 39 . The particle acceleration component is used to accelerate particles and spray the particles onto the rock wall near the borehole through the particle nozzle 39 .

[0047] In the rock breaking device, high-pressure liquid nitrogen is first injected into the rock wall through the hollow drill rod 17, so that the liquid nitrogen diffuses around the borehole. Under the action of liquid nitrogen, the rock mass is frozen and cracked, making the rock mass gradually brittle and generating cracks inside. Then, the particles are accelerated to a higher speed through the particle acceleration component, and the high-speed particles are shot to the rock wall around the borehole through the particle nozzle 39, so that the rock mass is broken under the impact of the particles. Due to the weakening effect of liquid nitrogen, the brittleness of the rock mass increases and cracks are generated inside, and the high-speed particles have sufficient impact energy to break the weakened hard rock. The rock breaking device not only gets rid of the problem of wear of traditional mechanical rock breaking tools, but also greatly improves the drilling efficiency. The rock breaking device can realize water-free operation throughout the whole process, and there is basically no residue after the liquid nitrogen is vaporized, making the rock breaking construction process safer and more environmentally friendly.

[0048] A drill bit 18 is connected to the front end of the hollow drill rod 17 , a bridge plug 21 and a packer 19 are arranged at intervals on the hollow drill rod 17 behind the drill bit 18 , and a liquid nitrogen nozzle 20 is located on the hollow drill rod 17 between the bridge plug 21 and the packer 19 .

[0049] In one embodiment of the present application, a hollow drill rod 17 is installed on a drilling rig 16, and the drill rod and the drill bit 18 are driven to rotate by the drilling rig 16 to drill a borehole on the rock wall. After the hole is cleaned, the hollow drill rod 17 with a liquid nitrogen nozzle 20 is inserted into the borehole; then, liquid nitrogen in a high-pressure state is input into the hollow drill rod 17 through a liquid supply assembly, and the bridge plug 21 and the packer 19 can seal the gap between the hollow drill rod 17 and the borehole, thereby preventing liquid nitrogen from escaping from the borehole and allowing the liquid nitrogen to penetrate into the rock mass around the borehole, thereby expanding the weakening range of the rock mass as much as possible.

[0050] The liquid supply assembly at least includes a self-pressurized liquid nitrogen storage tank 1 and a liquid nitrogen buffer tank 8, which are connected by a first pipeline. The self-pressurized liquid nitrogen storage tank 1 is used to charge liquid nitrogen into the hydraulic buffer tank, and a first solenoid valve 7 is provided on the first pipeline. In one embodiment of the present application, the on-off of the first pipeline is controlled by the first solenoid valve 7; the self-pressurized liquid nitrogen storage tank 1 charges the liquid nitrogen into the liquid nitrogen buffer tank 8 through the first pipeline, and the liquid nitrogen in the liquid nitrogen buffer tank 8 is transported to the hollow drill rod 17 after being pressurized.

[0051] In this embodiment, a liquid nitrogen buffer tank 8 is arranged downstream of the self-pressurized liquid nitrogen storage tank 1, and the required amount of liquid nitrogen for each use is first transferred to the liquid nitrogen buffer tank 8, and then the liquid nitrogen is released from the liquid nitrogen buffer tank 8 and pressurized before being input into each hollow drill rod 17; such an arrangement can further increase the safety of the rock breaking device during use.

[0052] In this embodiment, the self-pressurizing liquid nitrogen storage tank 1 includes an inner tank 2 and an outer shell 3, and is provided with a boosting valve 4, a safety valve 5 and a vent valve 6.

[0053] The liquid supply assembly further includes a liquid pump 10, which is disposed downstream of the buffer tank and is used to pressurize the liquid nitrogen in the liquid nitrogen buffer tank 8 into a liquid nitrogen jet;

[0054] The liquid inlet of the liquid pump 10 is connected to the liquid nitrogen buffer tank 8 through a second pipeline, and a second solenoid valve 9 is arranged on the second pipeline.

[0055] In one embodiment of the present application, the on-off of the second pipe chain is controlled by the second solenoid valve 9; and the liquid pump 10 is a reciprocating cryogenic liquid pump 10, which pressurizes the liquid nitrogen in the liquid nitrogen buffer tank 8 to convert the liquid nitrogen into a liquid nitrogen jet, which is then input into the hollow drill rod 17 to be ejected toward the rock mass, thereby increasing the penetration energy of the liquid nitrogen and the weakening effect on the rock mass.

[0056] The driving source of the liquid pump 10 includes a frequency conversion control box 13, a motor 12 and a transmission box 11. The output end of the motor 12 is connected to the input end of the transmission box 11, and the output end of the transmission box 11 is connected to the input shaft of the liquid pump 10; the frequency conversion control box 13 is connected to the motor 12 to control the speed of the motor 12. In one embodiment of the present application, a transmission box 11 is arranged between the liquid pump 10 and the motor 12 for transmission, and the transmission box 11 plays the role of deceleration and torque increase; and the speed of the motor 12 is controlled by the frequency conversion control box 13, so as to achieve precise adjustment of the working pressure and injection frequency of the reciprocating cryogenic liquid pump 10, and then realize the injection of liquid nitrogen into the rock body according to the required pressure and injection frequency for different rock conditions.

[0057] The liquid outlet of the liquid pump 10 is connected to a third pipeline, and a third solenoid valve 15 and a pressure gauge 13 are arranged on the third pipeline; the third pipeline is connected to a plurality of hollow drill rods 17 through a branch pipe, so that the liquid pump 10 can simultaneously deliver pressurized liquid nitrogen jets to the plurality of hollow drill rods 17. In one embodiment of the present application, the third solenoid valve 15 is used to control the on-off of the third pipeline, and the pressure gauge 13 is used to measure the pressure of the liquid nitrogen in the third pipeline to determine whether the liquid nitrogen delivered to the hollow drill rod 17 reaches the set pressure. At the same time, multiple sets of drilling rigs 16 and drill rods are arranged, so that each hollow drill rod 17 is connected to the third pipeline through a branch pipe, so that the liquid pump 10 can simultaneously deliver pressurized liquid nitrogen jets to the plurality of hollow drill rods 17, so that the plurality of hollow drill rods 17 can simultaneously spray liquid nitrogen jets into a larger range of rock bodies, so as to maximize the range of rock bodies weakened by liquid nitrogen, and achieve a better effect of weakening the rock bodies.

[0058] The particle acceleration assembly includes a particle acceleration tube 27, a striker rod 28, an air compressor 24 and a gas cylinder 22, wherein the striker rod 28 is guided and moved in the particle acceleration tube 27;

[0059] The gas cylinder 22 is connected to the air compressor 24 through a pipeline for supplying gas to the air compressor 24. A gas cylinder valve 22 is provided on the pipeline between the gas cylinder 22 and the air compressor 24.

[0060] The air compressor 24 is connected to the particle acceleration tube 27 through a pipeline, and is used to provide compressed gas to the particle acceleration tube 27 .

[0061] In one embodiment of the present application, the gas cylinder valve 22 is used to control the gas cylinder 22 to supply gas to the air machine, wherein a plurality of gas cylinders 22 may be provided, and the plurality of gas cylinders 22 are connected in parallel on a pipeline connected to the air machine, and a gas cylinder valve 22 is provided at the gas outlet position of each gas cylinder 22.

[0062] A ball valve 25 and a pressure gauge 26 are provided on the pipeline between the air compressor 24 and the particle accelerator tube 27. The ball valve 25 is used to control the on-off of the pipeline, and the pressure gauge 26 is used to monitor whether the gas pressure after the air compressor pressurizes reaches the standard. The gas in the gas cylinder 22 is compressed by the air compressor 24 and then input into the particle accelerator tube 27. The impact rod 28 is pushed by the high-pressure gas to move at a high speed in the particle accelerator tube 27, so that the impact rod 28 hits the particles at a high speed, so that the particles obtain greater kinetic energy, and are ejected from the particle nozzle 39 to hit the rock mass weakened by liquid nitrogen, thereby crushing the rock mass.

[0063] The particle acceleration assembly further includes a particle filling mechanism, which includes at least a sleeve 33 and an inner tube 36. The inner tube 36 is disposed inside the sleeve 33 and is connected to one side of the particle acceleration tube 27 to provide particles to the particle acceleration tube 27.

[0064] One side of the inner tube 36 is connected to a particle bin 31 through a pipeline, and the particle bin 31 is used to replenish particles into the inner tube 36 .

[0065] In one embodiment of the present application, the particles contained in the particle bin 31 can be particles of a material with relatively high hardness, such as iron particles or steel particles. A particle valve 32 is provided on the pipeline between the particle bin 31 and the inner tube 36. The particle valve 32 is used to control the on-off of the pipeline to control the particle bin 31 to replenish and transport particles to the inner tube 36.

[0066] A base 37 is provided at the lower part of the sleeve 33, and the inner tube 36 extends into the base 37. A bottom plate is provided at the lower part of the inner tube 36. A guide seal in the inner tube 36 is matched with a backing plate 34. A spring 35 is provided between the backing plate 34 and the bottom plate. A plurality of particles are supported above the backing plate 34.

[0067] The particle filling mechanism further includes a vacuum pump 30. A fourth pipeline is provided between the vacuum pump 30 and the particle acceleration tube 27. A fourth solenoid valve 29 is provided on the fourth pipeline for controlling the resetting of the impact rod 28.

[0068] A fifth pipeline is provided between the vacuum pump 30 and the bottom plate. The fifth pipeline penetrates the bottom plate and extends into the inner tube 36 . A fifth solenoid valve 38 is provided on the fifth pipeline for compressing the spring 35 .

[0069] In one embodiment of the present application, the pad 34 is pushed by the spring 35 , and the pad 34 pushes the particles in the inner tube 36 , so that the particles are pushed into the particle acceleration tube 27 , so that the impact rod 28 impacts and accelerates the particles.

[0070] The fourth solenoid valve 29 is used to control the on-off of the fourth pipeline. When the fourth solenoid valve 29 is opened, the particle accelerator tube 27 is evacuated by the vacuum pump 30 to generate negative pressure inside the particle accelerator tube 27, thereby resetting the impact rod 28 to its original position for the next impact process.

[0071] The fifth solenoid valve 38 is used to control the on-off of the fifth pipeline. When the fifth solenoid valve 38 is opened, the inner tube 36 between the pad 34 and the bottom plate is evacuated by the vacuum pump 30 to generate negative pressure, so that the pad 34 compresses the spring 35. At this time, the particle valve 32 is opened to replenish the particles in the particle bin 31 into the inner tube 36.

[0072] The present application also provides a rock breaking method using a liquid nitrogen jet combined with particle impact, the rock breaking method using the above-mentioned rock breaking device using a liquid nitrogen jet combined with particle impact, the rock breaking method comprising the following steps:

[0073] Step 1, first drill a plurality of boreholes on the rock wall, and then insert a plurality of hollow drill rods 17 connected with a liquid supply assembly into each borehole;

[0074] Step 2, opening the first solenoid valve 7, so that the self-pressurized liquid nitrogen storage tank 1 delivers a set amount of liquid nitrogen to the liquid nitrogen buffer tank 8, and then closing the first solenoid valve 7;

[0075] Step 3, open the second solenoid valve 9 and the third solenoid valve 15, and turn on the liquid pump 10, the liquid pump 10 pressurizes the liquid nitrogen in the liquid nitrogen buffer tank 8 into a liquid nitrogen jet, transmits it to the hollow drill rod 17, and sprays the liquid nitrogen jet into the rock mass through the liquid nitrogen nozzle 20 on the hollow drill rod 17, and continuously sprays the liquid nitrogen into the rock mass at a set pressure for a set time;

[0076] Step 4, open the gas cylinder valve 22, start the air compressor 24 to compress the gas and transmit it to the particle acceleration tube 27, the impact rod 28 moves at high speed along the particle acceleration tube 27 under the action of high-pressure air to impact the particles, so that the particles are ejected from the particle nozzle 39 at high speed, and the particles are sprayed onto the rock wall between the four boreholes to break the rock mass; open the fourth solenoid valve 29, and start the vacuum pump 30 to reset the impact rod 28; then repeat the above process, so that the particles repeatedly impact and break the rock wall; in this embodiment, the particles impact on the rock wall between the four boreholes, so that the liquid nitrogen jets emitted by the multiple hollow drill rods 17 and the particle impact action are coupled with each other as much as possible, so as to achieve a better rock breaking effect.

[0077] Step 5. When the particles in the inner tube 36 are used up, open the fifth solenoid valve 38 and the particle valve 32, and start the vacuum pump 30 so that the pad 34 presses down the spring 35. At this time, the particles in the particle bin 31 are replenished into the inner tube 36. In this embodiment, the vacuum pump 30 can be used to generate negative pressure in the particle mounting tube to facilitate the resetting of the impact rod 28, and can also be used to generate negative pressure in the inner tube 36 to make the pad 34 compress the spring 35 to facilitate the replenishment of particles into the inner tube 36.

[0078] Step 6: Repeat steps 1-5 until the set rock excavation task is completed.

[0079] It should be understood that the above description is merely exemplary and the embodiments of the present application do not limit this.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A rock breaking device combining liquid nitrogen jet and particle impact, characterized in that: The rock breaking device includes a liquid nitrogen injection fracturing system and a particle impact system; The liquid nitrogen jet fracturing system comprises at least a liquid supply assembly and a hollow drill rod, wherein the liquid supply assembly is used to provide pressurized liquid nitrogen to the hollow drill rod, a plurality of liquid nitrogen nozzles are arranged on the circumference of the hollow drill rod, and the hollow drill rod is used to spray liquid nitrogen into the rock body through the liquid nitrogen nozzles in the borehole on the rock wall; The particle impact system comprises a particle acceleration component and a particle nozzle. The particle acceleration component is used to accelerate particles and spray the particles onto a rock wall near the borehole through the particle nozzle.

2. The rock breaking device of liquid nitrogen jet combined with particle impact according to claim 1 is characterized in that: The front end of the hollow drill rod is connected with a drill bit, a bridge plug and a packer are arranged at intervals on the hollow drill rod behind the drill bit, and the liquid nitrogen nozzle is located on the hollow drill rod between the bridge plug and the packer.

3. The rock breaking device of liquid nitrogen jet combined with particle impact according to claim 2 is characterized in that: The liquid supply assembly includes at least a self-pressurized liquid nitrogen storage tank and a liquid nitrogen buffer tank. The self-pressurized liquid nitrogen storage tank and the liquid nitrogen buffer tank are connected through a first pipeline. The self-pressurized liquid nitrogen storage tank is used to charge liquid nitrogen into the hydraulic buffer tank. A first solenoid valve is provided on the first pipeline.

4. The rock breaking device of liquid nitrogen jet combined with particle impact according to claim 3 is characterized in that: The liquid supply assembly further includes a liquid pump, which is disposed downstream of the buffer tank and is used to pressurize the liquid nitrogen in the liquid nitrogen buffer tank and convert it into a liquid nitrogen jet; The liquid inlet of the liquid pump is connected to the liquid nitrogen buffer tank through a second pipeline, and a second solenoid valve is arranged on the second pipeline.

5. The rock breaking device of liquid nitrogen jet combined with particle impact according to claim 4 is characterized in that: The driving source of the liquid pump includes a frequency conversion control box, a motor and a transmission box. The output end of the motor is transmission-connected to the input end of the transmission box, and the output end of the transmission box is transmission-connected to the input shaft of the liquid pump. The frequency conversion control box is connected to the motor to control the speed of the motor.

6. The rock breaking device of liquid nitrogen jet combined with particle impact according to claim 4 is characterized in that: The liquid outlet of the liquid pump is connected to a third pipeline, on which a third solenoid valve and a pressure gauge are arranged; the third pipeline is connected to a plurality of hollow drill rods through a branch pipe, so that the liquid pump can simultaneously deliver pressurized liquid nitrogen jets to the plurality of hollow drill rods.

7. The rock breaking device of liquid nitrogen jet combined with particle impact according to claim 6 is characterized in that: The particle acceleration assembly includes a particle acceleration tube, an impact rod, an air compressor and a gas cylinder, wherein the impact rod is guided and moved in the particle acceleration tube; The gas cylinder is connected to the air compressor via a pipeline for supplying gas to the air compressor, and a gas cylinder valve is provided on the pipeline between the gas cylinder and the air compressor; The air compressor is connected to the particle acceleration tube through a pipeline and is used to provide compressed gas to the particle acceleration tube.

8. The rock breaking device of liquid nitrogen jet combined with particle impact according to claim 7, characterized in that: The particle acceleration assembly further includes a particle filling mechanism, which includes at least a sleeve and an inner tube, wherein the inner tube is arranged inside the sleeve and is connected to one side of the particle acceleration tube, and is used to provide particles into the particle acceleration tube; One side of the inner tube is connected to a particle bin through a pipeline, and the particle bin is used to replenish particles into the inner tube.

9. The rock breaking device of liquid nitrogen jet combined with particle impact according to claim 8, characterized in that: The lower part of the sleeve is provided with a base, the inner tube extends into the base, the lower part of the inner tube is provided with a bottom plate, the guide seal in the inner tube is matched with a pad, a spring is provided between the pad and the bottom plate, and a plurality of particles are supported above the pad; The particle filling mechanism further comprises a vacuum pump, a fourth pipeline is arranged between the vacuum pump and the particle acceleration tube, and a fourth solenoid valve is arranged on the fourth pipeline for controlling the resetting of the impact rod; A fifth pipeline is arranged between the vacuum pump and the bottom plate, the fifth pipeline passes through the bottom plate and extends into the inner tube, and a fifth solenoid valve is arranged on the fifth pipeline for compressing the spring.

10. A rock breaking method using liquid nitrogen jet combined with particle impact, characterized in that: The rock breaking method uses the rock breaking device of liquid nitrogen jet combined with particle impact as claimed in claim 9, and the rock breaking method comprises the following steps: Step 1, firstly drill a plurality of boreholes on the rock wall, and then insert a plurality of hollow drill rods connected with a fluid supply assembly into each borehole; Step 2, opening the first solenoid valve to allow the self-pressurized liquid nitrogen storage tank to deliver a set amount of liquid nitrogen to the liquid nitrogen buffer tank, and then closing the first solenoid valve; Step 3, open the second solenoid valve and the third solenoid valve, and turn on the liquid pump. The liquid pump pressurizes the liquid nitrogen in the liquid nitrogen buffer tank into a liquid nitrogen jet, transmits it to the hollow drill pipe, and sprays the liquid nitrogen jet into the rock mass through the liquid nitrogen nozzle on the hollow drill pipe, and continuously sprays liquid nitrogen into the rock mass at a set pressure for a set time; Step 4, open the gas cylinder valve, start the air compressor to compress the gas and transmit it to the particle acceleration tube, the impact rod moves at high speed along the particle acceleration tube under the action of high-pressure air to impact the particles, so that the particles are ejected from the particle nozzle at high speed, and the particles are sprayed onto the rock wall between the four boreholes to break the rock mass; open the fourth solenoid valve, and start the vacuum pump to reset the impact rod; then repeat the above process, so that the particles repeatedly impact and break the rock wall; Step 5, when the particles in the inner tube are used up, the fifth solenoid valve and the particle valve are opened, and the vacuum pump is started to make the pad press down the spring, and the particles in the particle bin are then added to the inner tube; Step 6: Repeat steps 1-5 until the set rock excavation task is completed.

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