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

Abstract

A rock breaking device and method that combines liquid nitrogen jets and particle impacts. [Solution] The rock breaking equipment includes a liquid nitrogen injection and fracturing system and a particle impact system. The liquid nitrogen injection and fracturing system includes at least a liquid supply assembly and a hollow drill rod. The liquid supply assembly supplies pressurized liquid nitrogen to the hollow drill rod, which is circumferentially provided with a plurality of liquid nitrogen nozzles. The hollow drill rod injects liquid nitrogen into the rock body through the liquid nitrogen nozzles in a drilled hole in the rock wall. The particle impact system includes a particle acceleration assembly and a particle nozzle. The particle acceleration assembly accelerates particles and injects them into the rock wall near the drill hole through the particle nozzle. This rock breaking equipment not only overcomes the wear problem of traditional mechanical rock breaking tools, but also greatly improves drilling efficiency. Moreover, this rock breaking equipment achieves anhydrous operation throughout the entire process, leaving almost no liquid nitrogen remaining after evaporation, making the rock breaking process safer and more environmentally friendly.

Description

[Technical Field]

[0001] The present invention relates to the technical field of rock formation excavation, and in particular to a rock breaking device and method that combines liquid nitrogen jet and particle impact. [Background technology]

[0002] Hard rock is unavoidable during coal mining and underground excavation. Common rock-breaking methods include drilling, which involves drilling a hole in advance, filling it with explosives, and then detonating the explosives, and mechanical rock-breaking. Mechanical rock-breaking refers to the use of mechanical rock-breaking equipment to apply a concentrated load to the rock from the outside, thereby breaking it up. Mechanical rock-breaking has the advantages of being safer and more efficient, and is now the mainstream method for underground construction.

[0003] However, when breaking hard rock using traditional mechanical rock breaking methods, the wear of the cutting tools is accelerated, which not only directly affects the efficiency of construction, but also makes the excavation surface unstable, and the replacement of the cutting tools is likely to cause construction accidents such as the collapse of the coal rock layer. How to reduce the wear of the cutting tools while simultaneously achieving a relatively good rock breaking effect is a bottleneck problem in realizing highly efficient rock excavation.

[0004] Therefore, there is a need to provide an improved technical solution to address the shortcomings of the prior art. Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION The object of the present invention is to overcome the above-mentioned shortcomings in the prior art, and the present invention provides a rock breaking device and a rock breaking method that combines liquid nitrogen jet and particle impact. [Means for solving the problem]

[0006] To achieve the above object, the present invention provides the following technical solutions.

[0007] A combined liquid nitrogen jet and particle impact rock breaking device including a liquid nitrogen jet fracturing system and a particle impact system, The liquid nitrogen injection fracturing system includes at least a liquid supply assembly and a hollow drill rod (hollow drilling rod, hollow boring rod), the liquid supply assembly supplies pressurized liquid nitrogen (pressurized liquid nitrogen) to the hollow drill rod, a plurality of liquid nitrogen nozzles are provided around the circumference of the hollow drill rod, and the hollow drill rod injects liquid nitrogen into the rock body through the liquid nitrogen nozzles in a drill hole (drilling hole) in the rock wall, the particle impact system includes a particle acceleration assembly and a particle nozzle, the particle acceleration assembly accelerates particles and injects the particles through the particle nozzle into a rock wall near a drill hole; a drill is connected to the tip of the hollow drill rod, and a bridge plug and a packer are provided at intervals on the hollow drill rod behind the drill; the liquid nitrogen nozzle is located on the hollow drill rod between the bridge plug and the packer; the liquid supply assembly includes at least an autoboosting calibre liquid nitrogen container and a liquid nitrogen buffer tank, the self-pressurizing liquid nitrogen storage tank and the liquid nitrogen buffer tank are connected via a first pipeline, the self-pressurizing liquid nitrogen storage tank fills a hydraulic buffer tank with liquid nitrogen, and a first solenoid valve is provided on the first pipeline; the liquid supply assembly further includes a liquid pump, the liquid pump is provided downstream of the buffer tank, and the liquid pump pressurizes the liquid nitrogen in the liquid nitrogen buffer tank into a liquid nitrogen jet; A liquid inlet (liquid inlet) of the liquid pump is connected to a liquid nitrogen buffer tank via a second pipeline, and a second electromagnetic valve is provided in the second pipeline; The particle acceleration assembly includes a particle acceleration tube, a collision rod, a pneumatic compressor, and a gas cylinder, and the collision rod is guided and moved in the particle acceleration tube; The gas cylinder is connected to the pneumatic machine via a pipe to supply gas to the pneumatic machine, and a gas cylinder valve is provided on the pipe between the gas cylinder and the pneumatic machine; the pneumatic machine is connected to the particle acceleration tube via a pipe and supplies compressed gas to the particle acceleration tube; the particle acceleration assembly further includes a particle filling mechanism, the particle filling mechanism including at least a sleeve and an inner tube, the inner tube being disposed inside the sleeve, the inner tube being in communication with one side of the particle acceleration tube, and providing particles to the particle acceleration tube; a particle storehouse is connected to one end of the inner pipe via a pipe, and the particle storehouse replenishes particles into the inner pipe; a base is provided at the bottom of the sleeve, the inner pipe is inserted into the base, a base plate is provided at the bottom of the inner pipe, a gasket is guided and fitted to the inner pipe for sealing, a spring is provided between the gasket and the base plate, and a plurality of particles are supported on an upper portion of the gasket; the particle filling mechanism further includes a vacuum pump, a fourth pipe line is provided between the vacuum pump and the particle acceleration tube, and a fourth solenoid valve is provided in the fourth pipe line to control resetting of the collision rod; a fifth pipe line is provided between the vacuum pump and the base plate, the fifth pipe line penetrates the base plate and enters the inner pipe, and a fifth solenoid valve that compresses the spring is provided in the fifth pipe line; This rock-breaking device combines a liquid nitrogen jet with particle impact, and the particles contained in the particle storehouse are iron or steel particles.

[0008] The present application further provides a method for breaking up rocks by combining a liquid nitrogen jet and particle impact, using the above-mentioned device for breaking up rocks by combining a liquid nitrogen jet and particle impact, the method comprising: Step 1 includes drilling a plurality of drill holes in a rock wall and then inserting a plurality of hollow drill rods, each having a fluid supply assembly connected thereto, into each of the drill holes; Step 2: opening the first solenoid valve to transfer a fixed amount of liquid nitrogen from the self-pressurized liquid nitrogen storage tank to the liquid nitrogen buffer tank, and then closing the first solenoid valve; Step 3: opening the second solenoid valve and the third solenoid valve and opening the liquid pump, which pressurizes the liquid nitrogen in the liquid nitrogen buffer tank into a liquid nitrogen jet and then sends it to the hollow drill rod, which injects the liquid nitrogen jet into the rock body through the liquid nitrogen nozzle in the hollow drill rod, and setting the time for continuing to inject liquid nitrogen into the rock body at the set pressure; Step 4: Open the gas cylinder valve, start the air compressor to compress the gas, and then send it to the particle acceleration tube. The collision rod moves along the particle acceleration tube at high speed under the action of high-pressure air, colliding with the particles, causing the particles to be ejected at high speed from the particle nozzle, and the particles are ejected into the rock wall between the four drills, thereby fracturing the rock body. Then, open the fourth solenoid valve, start the vacuum pump, and reset the collision rod. The above process is repeated, causing the particles to repeatedly impact and fractured the rock wall. Step 5: when there are no more particles in the inner tube, open the fifth solenoid valve and the particle valve, and start the vacuum pump, so that the gasket presses down the spring, and the particles in the particle storage are replenished into the inner tube; and step 6 of repeating steps 1 to 5 until the set rock excavation work is completed.

[0009] This rock-breaking device first injects high-pressure liquid nitrogen into the rock wall through a hollow drill rod and diffuses around the drill hole. Under the action of the liquid nitrogen, freeze-breaking occurs in the rock, gradually weakening it and creating internal cracks. Then, particles are accelerated to high speed through a particle acceleration assembly and injected into the rock wall around the drill hole through a particle nozzle, causing the rock to fracture through impact. The weakening effect of the liquid nitrogen makes the rock more brittle, creating internal cracks. The high-speed particles then have enough impact energy to fracture the weakened hard rock. This rock-breaking device not only overcomes the wear problem of traditional mechanical rock-breaking tools, but also significantly improves drilling efficiency. Furthermore, this rock-breaking device achieves anhydrous operation throughout the entire process, leaving almost no liquid nitrogen remaining after evaporation, making the rock-breaking process safer and more environmentally friendly.

[0010] The gas cylinder valve is opened and the air compressor is started to compress the gas, which is then sent to the particle acceleration tube. The impact rod moves at high speed along the particle acceleration tube under the action of high-pressure air, colliding with the particles and causing them to be ejected at high speed from the particle nozzle, which then ejects them onto the rock wall between the four drills and fractures the rock. The particles collide with the rock wall between the four drills, and the liquid nitrogen jets emitted from the multiple hollow drill rods and the particle collision action can be combined as much as possible to achieve a better rock fracture effect.

[0011] A vacuum pump can be used to generate negative pressure inside the particle installation tube, making it easier to reset the collision rod, and also to generate negative pressure inside the inner tube, which compresses the spring with the gasket and is convenient for refilling the inner tube with particles. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a structural schematic diagram of the rock breaking device. [Figure 2] FIG. 2 is a structural schematic diagram of a hollow drill rod. [Figure 3] 1 is a structural schematic diagram of a particle filling device. [Figure 4] FIG. 1 is a schematic diagram of an excavation work surface. DETAILED DESCRIPTION OF THE INVENTION

[0013] According to a specific embodiment of the present invention, as shown in Figures 1 to 4, the present invention provides a combined liquid nitrogen jet and particle impact rock breaking device, including a liquid nitrogen jet fracturing system and a particle impact system, The liquid nitrogen injection fracturing system includes at least a liquid supply assembly and a hollow drill rod (17), the liquid supply assembly supplies pressurized liquid nitrogen to the hollow drill rod (17), a plurality of liquid nitrogen nozzles (20) are provided around the circumference of the hollow drill rod (17), and the hollow drill rod (17) injects liquid nitrogen into the rock body through the liquid nitrogen nozzles (20) in a drilled hole in the rock wall; The particle bombardment system includes a particle acceleration assembly and a particle nozzle 39, which accelerates particles and ejects them through the particle nozzle 39 into the rock wall adjacent to the drill hole.

[0014] This rock-breaking device first injects high-pressure liquid nitrogen into the rock wall via a hollow drill rod 17, allowing the liquid nitrogen to diffuse around the drill hole. Under the action of the liquid nitrogen, freeze-breaking occurs in the rock, gradually weakening it and creating internal cracks. The particles are then accelerated to high speeds via a particle acceleration assembly and injected into the rock wall around the drill hole via a particle nozzle 39, causing the rock to fracture through impact. The weakening effect of the liquid nitrogen makes the rock more brittle, creating internal cracks, and the high-speed particles have enough impact energy to fracture the weakened hard rock. This rock-breaking device not only overcomes the wear problem of traditional mechanical rock-breaking tools, but also significantly improves drilling efficiency. Furthermore, the rock-breaking device achieves anhydrous operation throughout the entire process, leaving almost no liquid nitrogen behind after evaporation, making the rock-breaking process safer and more environmentally friendly.

[0015] A drill 18 is connected to the tip of the hollow drill rod 17, and a bridge plug 21 and a packer 19 are provided at intervals on the hollow drill rod 17 behind the drill 18, and a liquid nitrogen nozzle 20 is positioned on the hollow drill rod 17 between the bridge plug 21 and the packer 19.

[0016] In one embodiment of the present application, the hollow drill rod 17 is attached to a drilling rig 16, and the drill rod and drill 18 are rotated through the drilling rig 16 to drill a drill hole in the rock wall. After the hole is cleared, the hollow drill rod 17 with the liquid nitrogen nozzle 20 is inserted into the drill hole. Then, high-pressure liquid nitrogen is input into the hollow drill rod 17 through a liquid supply assembly, and the bridge plug 21 and the packer 19 can serve to seal the gap between the hollow drill rod 17 and the drill hole, thereby preventing the liquid nitrogen from escaping the drill hole and penetrating into the rock mass around the drill hole, thereby expanding the weakening area of ​​the rock mass as much as possible.

[0017] The liquid supply assembly includes at least a self-pressurizing liquid nitrogen storage tank 1 and a liquid nitrogen buffer tank 8. The self-pressurizing liquid nitrogen storage tank 1 and the liquid nitrogen buffer tank 8 are in communication with each other via a first pipeline. The self-pressurizing liquid nitrogen storage tank 1 fills the hydraulic buffer tank with liquid nitrogen, and the first pipeline is provided with a first solenoid valve 7. In one embodiment of the present application, the first pipeline is turned on and off via the first solenoid valve 7. The self-pressurizing liquid nitrogen storage tank 1 fills the liquid nitrogen buffer tank 8 with liquid nitrogen via 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.

[0018] In this embodiment, a liquid nitrogen buffer tank 8 is provided downstream of the self-pressurizing liquid nitrogen storage tank 1, and the required amount of liquid nitrogen is first transferred to the liquid nitrogen buffer tank 8 for each use, and the liquid nitrogen is released from the liquid nitrogen buffer tank 8 and pressurized before being input into each hollow drill rod 17. This arrangement further improves the safety of the rock breaking equipment usage process.

[0019] In this embodiment, the self-pressurizing liquid nitrogen storage tank 1 includes a liner 2 and a casing 3 on which a boost valve 4, a safety valve 5 and a vent valve 6 are provided.

[0020] The liquid supply assembly further includes a liquid pump 10, which is located downstream of the buffer tank and pressurizes the liquid nitrogen in the liquid nitrogen buffer tank 8 into a liquid nitrogen jet, and a second pipe line connects the liquid inlet of the liquid pump 10 to the liquid nitrogen buffer tank 8, and a second solenoid valve 9 is located in the second pipe line.

[0021] In one embodiment of the present application, the second chain (second pipeline) is controlled to be turned on and off via a second solenoid valve 9. The liquid pump 10 is a reciprocating cryogenic liquid pump 10, which pressurizes the liquid nitrogen in the liquid nitrogen buffer tank 8 through the liquid pump 10 and turns the liquid nitrogen into a liquid nitrogen jet, which is then input into a hollow drill rod 17 and injected into the rock mass, thereby increasing the penetration energy of the liquid nitrogen and its weakening effect on the rock mass.

[0022] 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 power-transmitted to the input end of the transmission box 11, and the output end of the transmission box 11 is power-transmitted to the input shaft of the liquid pump 10. The frequency conversion control box 13 is connected to the motor 12 and controls the rotation speed of the motor 12. In one embodiment of the present application, the transmission box 11 is installed between the liquid pump 10 and the motor 12 to transmit power and serves the role of reducing speed and increasing torque. By controlling the rotation speed of the motor 12 via the frequency conversion control box 13, the working pressure and injection frequency of the reciprocating cryogenic liquid pump 10 can be accurately adjusted, and liquid nitrogen can be injected into the rock body at the required pressure and injection frequency for different rock conditions.

[0023] A third pipeline is connected to the liquid outlet of the liquid pump 10, and a third solenoid valve 15 and a pressure gauge 14 are provided in the third pipeline. The third pipeline is connected to each of a plurality of hollow drill rods 17 via a branch pipe so that the liquid pump 10 can simultaneously deliver a pressurized liquid nitrogen jet to a 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 14 is used to measure the pressure of the liquid nitrogen in the third pipeline and to determine whether the liquid nitrogen being delivered to the hollow drill rods 17 has reached a set pressure. At the same time, multiple sets of drilling rigs 16 and drill rods are provided, and each hollow drill rod 17 is connected to a third pipeline via a branch pipe, and the liquid pump 10 can simultaneously deliver pressurized liquid nitrogen jets to multiple hollow drill rods 17, so that the multiple hollow drill rods 17 can simultaneously inject liquid nitrogen jets into a wider range of rock bodies, thereby maximizing the area of ​​the rock bodies weakened by the liquid nitrogen and achieving a better weakening effect on the rock bodies.

[0024] The particle acceleration assembly includes a particle acceleration tube 27, a collision rod 28, a pneumatic machine 24, and a gas cylinder 22, and the collision rod 28 is moved while being guided in the particle acceleration tube 27. The gas cylinder 22 is connected to the pneumatic machine 24 via a pipe and supplies gas to the pneumatic machine 24, and a gas cylinder valve 23 is provided on the pipe between the gas cylinder 22 and the pneumatic machine 24. The pneumatic machine 24 is connected to the particle acceleration tube 27 via a pipe and supplies compressed gas to the particle acceleration tube 27.

[0025] In one embodiment of the present application, the gas cylinder valve 23 is used to control the gas supply from the gas cylinder 22 to the air machine, however, multiple gas cylinders 22 may be provided, and the multiple gas cylinders 22 are connected in parallel to a pipe connected to the air machine, and one gas cylinder valve 23 is provided at the gas outlet position of each gas cylinder 22.

[0026] The pipe between the air compressor 24 and the particle acceleration tube 27 is equipped with a ball valve 25 for controlling the on / off of this pipe, and a pressure gauge 26 for monitoring whether the gas pressure after being pressurized by the air compressor has reached a standard. The gas in the gas cylinder 22 is compressed via the air compressor 24 and then input into the particle acceleration tube 27, and the high-pressure gas pressurizes the collision rod 28, causing it to move at high speed in the particle acceleration tube 27, causing the collision rod 28 to collide with particles at high speed, giving the particles a large amount of kinetic energy which is then ejected from the particle nozzle 39 and collided with the weakened rock body by the liquid nitrogen, destroying the rock body.

[0027] 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 being provided inside the sleeve 33 and communicating with one end of the particle acceleration tube 27 to provide particles to the particle acceleration tube 27. One end of the inner tube 36 is communicated with a particle storehouse 31 via a pipe, and the particle storehouse 31 replenishes particles to the inner tube 36.

[0028] In one embodiment of the present application, the particles contained in the particle storehouse 31 may be particles of a hard material such as iron particles or steel particles, and a particle valve 32 is provided in the pipe between the particle storehouse 31 and the inner pipe 36, and the particle valve 32 is used to control the on / off of the pipe so that the particle storehouse 31 controls the replenishment and transport of particles to the inner pipe 36.

[0029] A pedestal 37 is provided at the bottom of the sleeve 33, the inner tube 36 fits into the pedestal 37, a base plate is provided at the bottom of the inner tube 36, a gasket 34 is guided and fitted to the inner tube 36 for sealing, a spring 35 is provided between the gasket 34 and the base plate, and a plurality of particles are supported on the top of the gasket 34. The particle filling mechanism further includes a vacuum pump 30, a fourth pipe line is provided between the vacuum pump 30 and the particle acceleration tube 27, and a fourth solenoid valve 29 is provided in the fourth pipe line to control resetting of the collision rod 28. A fifth pipe line is provided between the vacuum pump 30 and the base plate, and the fifth pipe line passes through the base plate and enters the inner pipe 36. A fifth solenoid valve 38 that compresses the spring 35 is provided in the fifth pipe line.

[0030] In one embodiment of the present application, a spring 35 presses a gasket 34, which presses against particles inside the inner tube 36 so that the collision rod 28 collides and accelerates the particles, forcing the particles into the particle acceleration tube 27.

[0031] The fourth solenoid valve 29 is used to control the on / off of the fourth pipe line. After the fourth solenoid valve 29 is opened, the particle acceleration tube 27 is evacuated through the vacuum pump 30, generating negative pressure inside the particle acceleration tube 27, which resets the collision rod 28 to its original position and facilitates the next collision process.

[0032] The fifth solenoid valve 38 is used to control the on / off of the fifth pipeline. After the fifth solenoid valve 38 opens, the inner pipe 36 between the gasket 34 and the base plate is evacuated via the vacuum pump 30 to generate negative pressure, causing the gasket 34 to compress the spring 35. At this time, the particle valve 32 is opened, and the particles in the particle warehouse 31 are replenished into the inner pipe 36.

[0033] The present application further provides a method for breaking rocks by combining a liquid nitrogen jet and particle impact using the above-mentioned device for breaking rocks by combining a liquid nitrogen jet and particle impact, the method comprising: Step 1 includes drilling a plurality of drill holes in a rock wall and then inserting a plurality of hollow drill rods 17, each having a liquid supply assembly connected thereto, into each of the drill holes; Step 2: opening the first solenoid valve 7, transferring a fixed amount of liquid nitrogen from the self-pressurized liquid nitrogen storage tank 1 to the liquid nitrogen buffer tank 8, and then closing the first solenoid valve 7; Step 3: opening the second solenoid valve 9 and the third solenoid valve 15, and opening the liquid pump 10, which pressurizes the liquid nitrogen in the liquid nitrogen buffer tank 8 into a liquid nitrogen jet, and then sends it to the hollow drill rod 17, which injects the liquid nitrogen jet into the rock body through the liquid nitrogen nozzle 20 of the hollow drill rod 17, and sets the time for continuing to inject liquid nitrogen into the rock body at the set pressure; Step 4: Open the gas cylinder valve 23, start the air compressor 24 to compress the gas, and then send it to the particle acceleration tube 27. The collision rod 28 moves along the particle acceleration tube 27 at high speed under the action of high-pressure air, colliding with the particles, causing the particles to be ejected at high speed from the particle nozzle 39, and the particles are ejected into the rock wall between the four drills, thereby fracturing the rock body. Open the fourth solenoid valve 29, start the vacuum pump 30, and reset the collision rod 28. The above process is repeated, causing the particles to repeatedly impact and fracture the rock wall. In this embodiment, the particles collide with the rock wall between the four drills. The liquid nitrogen jets emitted from the multiple hollow drill rods 17 and the particle collision action can be combined as much as possible to achieve a better rock fracturing effect. Step 5: When the particles in the inner tube 36 are exhausted, open the fifth solenoid valve 38 and the particle valve 32, and start the vacuum pump 30, so that the gasket 34 presses down on the spring 35, and the particles in the particle storage 31 are replenished into the inner tube 36. In this embodiment, the vacuum pump 30 generates negative pressure inside the particle installation tube, which facilitates resetting of the collision rod 28, and can also be used to generate negative pressure inside the inner tube 36, which causes the gasket 34 to compress the spring 35 and facilitates replenishing particles into the inner tube 36. and step 6 of repeating steps 1 to 5 until the set rock excavation work is completed. [Explanation of symbols]

[0034] 1. Self-pressurized liquid nitrogen storage tank 2 Liner 3 Casing 4. Pressure booster 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 motors 13 Frequency conversion control box 14 Pressure gauge 15 Third solenoid valve 16 Drilling Rig 17 Hollow drill rod 18 Drill 19. Packer 20 Liquid nitrogen nozzle 21 Bridge plug 22 Gas Cylinder 23 Gas cylinder valve 24 Pneumatic Machine 25 Ball Valve 26 Pressure gauge 27 Particle Accelerator Tube 28 Collision rod 29 Fourth solenoid valve 30 Vacuum Pump 31 Particle Warehouse 32 Particle Valve 33 Sleeve 34 Gasket 35 Spring 36 Inner tube 37 Pedestal 38 Fifth solenoid valve 39 Particle Nozzle

Claims

1. A combined liquid nitrogen jet and particle impact rock breaking device including a liquid nitrogen jet fracturing system and a particle impact system, The liquid nitrogen injection fracturing system includes at least a liquid supply assembly and a hollow drill rod, the liquid supply assembly supplies pressurized liquid nitrogen to the hollow drill rod, and a plurality of liquid nitrogen nozzles are provided around the hollow drill rod, and the hollow drill rod injects liquid nitrogen into the rock body through the liquid nitrogen nozzles in a drilled hole in the rock wall; the particle impact system includes a particle acceleration assembly and a particle nozzle, the particle acceleration assembly accelerates particles and injects the particles through the particle nozzle into a rock wall near a drill hole; a drill is connected to the tip of the hollow drill rod, and a bridge plug and a packer are provided at an interval on the hollow drill rod behind the drill; the liquid nitrogen nozzle is located on the hollow drill rod between the bridge plug and the packer; the liquid supply assembly includes at least a self-pressurizing liquid nitrogen storage tank and a liquid nitrogen buffer tank, the self-pressurizing liquid nitrogen storage tank and the liquid nitrogen buffer tank are connected via a first pipeline, the self-pressurizing liquid nitrogen storage tank fills a hydraulic buffer tank with liquid nitrogen, and a first solenoid valve is provided in the first pipeline; the liquid supply assembly further includes a liquid pump, the liquid pump is provided downstream of the buffer tank, and the liquid pump pressurizes the liquid nitrogen in the liquid nitrogen buffer tank into a liquid nitrogen jet; The liquid inlet of the liquid pump and the liquid nitrogen buffer tank are connected via a second pipe line, and a second solenoid valve is provided in the second pipe line. the particle acceleration assembly includes a particle acceleration tube, a collision rod, a pneumatic compressor, and a gas cylinder, the collision rod being guided and moved in the particle acceleration tube; The gas cylinder is connected to the pneumatic machine via a pipe to supply gas to the pneumatic machine, and a gas cylinder valve is provided on the pipe between the gas cylinder and the pneumatic machine; the pneumatic machine is connected to the particle acceleration tube via a pipe and supplies compressed gas to the particle acceleration tube; the particle acceleration assembly further includes a particle filling mechanism, the particle filling mechanism including at least a sleeve and an inner tube, the inner tube being disposed inside the sleeve, the inner tube being in communication with one end of the particle acceleration tube, and providing particles to the particle acceleration tube; a particle storehouse is connected to one end of the inner pipe via a pipe, and the particle storehouse replenishes particles into the inner pipe; a base is provided at the bottom of the sleeve, the inner pipe is inserted into the base, a base plate is provided at the bottom of the inner pipe, a gasket is guided and fitted to the inner pipe for sealing, a spring is provided between the gasket and the base plate, and a plurality of particles are supported on an upper portion of the gasket; the particle filling mechanism further includes a vacuum pump, a fourth pipe line is provided between the vacuum pump and the particle acceleration tube, and a fourth electromagnetic valve is provided in the fourth pipe line to control resetting of the collision rod; a fifth pipe line is provided between the vacuum pump and the base plate, the fifth pipe line passes through the base plate and enters the inner pipe, and a fifth solenoid valve is provided in the fifth pipe line to compress the spring; A rock breaking device that combines a liquid nitrogen jet and particle impact, characterized in that the particles contained in the particle storehouse are iron particles or steel particles.

2. The liquid pump driving source 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, the output end of the transmission box is transmission-connected to the input shaft of the liquid pump, and the frequency conversion control box is connected to the motor and controls the rotation speed of the motor.

3. 2. The rock breaking device combining liquid nitrogen jet and particle impact as claimed in claim 1, characterized in that a third pipeline is connected to the liquid outlet of the liquid pump, and a third solenoid valve and a pressure gauge are provided in the third pipeline, and the third pipeline is connected to each of a plurality of hollow drill rods via one branch pipe so that the liquid pump can simultaneously deliver the pressurized liquid nitrogen jet to a plurality of hollow drill rods.

4. A method for breaking up rocks using the liquid nitrogen jet and particle impact combined rock breaking device according to claim 3, Step 1 includes drilling a plurality of drill holes in a rock wall and then inserting a plurality of hollow drill rods, each having a liquid supply assembly connected thereto, into each of the drill holes; Step 2: opening the first solenoid valve to transfer a fixed amount of liquid nitrogen from the self-pressurized liquid nitrogen storage tank to the liquid nitrogen buffer tank, and then closing the first solenoid valve; Step 3: opening the second solenoid valve and the third solenoid valve and opening the liquid pump, which pressurizes the liquid nitrogen in the liquid nitrogen buffer tank into a liquid nitrogen jet and then sends it to the hollow drill rod, which injects the liquid nitrogen jet into the rock body through the liquid nitrogen nozzle in the hollow drill rod, and sets the time for continuing to inject liquid nitrogen into the rock body at the set pressure; Step 4: Open the gas cylinder valve, start the air compressor to compress the gas, and then send it to the particle acceleration tube. The collision rod moves along the particle acceleration tube at high speed under the action of high-pressure air, colliding with the particles, causing the particles to be ejected at high speed from the particle nozzle, and the particles are ejected into the rock wall between the four drills, thereby fracturing the rock body. Open the fourth solenoid valve, start the vacuum pump, and reset the collision rod. Repeat the above process to repeatedly impact the particles and fractured the rock wall. Step 5: when there are no more particles in the inner tube, open the fifth solenoid valve and the particle valve, and start the vacuum pump, so that the gasket presses down the spring, and the particles in the particle storage are replenished into the inner tube; and step 6, repeating steps 1 to 5 until the set rock excavation work is completed.

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