Electrical explosion excited liquid co2 powder suspension phase transition shock combined rock fracturing system

Abstract

The present application relates to rock mass mining technical field, disclose electric explosion excitation liquid CO2 powder suspension phase change impact composite rock breaking system, including: high voltage pulse device, high voltage pulse device includes high voltage energy storage module, pulse excitation module and switch module;Cracking pipe, the liquid carbon dioxide phase change module, the deflagration suspension powder module and the constant pressure energy release module are arranged in the cracking pipe;The top of cracking pipe is provided with electric explosion excitation unit;The rock mass to be exploded, the drill hole is opened in the centre of the rock mass to be exploded, the cracking pipe is placed in the drill hole, and the gap between the cracking pipe wall and the drill hole wall is sealed by epoxy resin to prevent energy leakage.The present application utilizes high voltage pulse electric explosion trigger, suspension powder deflagration energy increase and induces liquid carbon dioxide phase change expansion to realize triple energy increase, and can be used for hard rock crushing, directional cracking, fracture propagation and deep rock mass simulation test scene.

Description

Technical Field

[0001] This invention relates to the field of rock mining technology, and in particular to a composite rock-breaking system for phase change impact of electrically ignited liquid CO2 powder suspension. Background Technology

[0002] Rock breaking technology is widely used in mining, tunneling, and underground engineering. Its breaking efficiency, safety, and environmental impact directly affect project quality and construction safety. Commonly used rock breaking methods in existing projects include explosive blasting, mechanical breaking, hydraulic fracturing, and gas expansion fracturing.

[0003] Liquid carbon dioxide phase change fracturing technology involves heating liquid carbon dioxide to induce a phase change expansion within a confined space, resulting in a 600-fold expansion from its original volume. This releases high-pressure gas that causes tensile damage to the rock mass, with peak blasting pressures reaching 100 to 300 MPa. It offers advantages such as high safety and environmental friendliness. However, the energy release of this technology relies primarily on heat conduction and the phase change process, resulting in a relatively low pressure rise rate. This makes it difficult to generate high strain rate impact loads, and initial fractures are unlikely to form directly in rock masses with high integrity and strength.

[0004] Electric blasting technology uses high-voltage pulsed current to cause an electrical explosion in a conductor, instantly generating high-temperature plasma and a strong shock wave. This can create micro-fractures near the borehole wall in a very short time. The blasting pressure can be controlled by adjusting the charge of the capacitor bank, offering advantages such as safety, controllability, and no pollution. However, due to the short impact time, rapid pressure decay, and lack of sustained crack propagation capacity, the overall rock mass fragmentation effect is limited.

[0005] In summary, existing technologies generally suffer from problems such as the inability of a single energy form to simultaneously meet the needs of rock mass crack initiation and propagation, lack of time-series coordination in energy release, and low energy utilization efficiency. There is an urgent need for a new rock fracturing scheme that can organically combine transient impact with continuous energy release to achieve integrated linkage and composite energy enhancement for efficient fracturing. Through structural and energy coupling design, the efficiency and controllability of crack formation can be fundamentally improved. Summary of the Invention

[0006] The purpose of this invention is to provide an electrically ignited liquid CO2 powder suspension phase change impact composite rock-breaking system, which aims to solve the problems of rapid energy dissipation and low fracturing efficiency.

[0007] To achieve the above objectives, the present invention provides the following solution: The present invention provides an electrically ignited liquid CO2 powder suspension phase change impact composite fracturing rock breaking system, comprising... A high-voltage pulse device includes a high-voltage energy storage module, a pulse excitation module, and a switching module. The high-voltage energy storage module provides a controllable high-voltage DC output to charge and store energy for the pulse excitation module. The pulse excitation module stores electrical energy and releases it to form a pulse upon triggering. The switching module rapidly releases the energy stored in the capacitor into a high-voltage pulse when the triggering conditions are met. A fracturing tube is provided, which contains a liquid carbon dioxide phase change module, a deflagration suspended powder module, and a constant pressure energy release module; an electro-explosion excitation unit is provided at the top of the fracturing tube, and the liquid carbon dioxide phase change module and the deflagration suspended powder module are electrically connected to the high-voltage pulse device through the electro-explosion excitation unit. A rock block to be detonated, wherein a drill hole is formed in the center of the rock block, and the fracturing tube is located inside the drill hole.

[0008] Preferably, the fracturing tube has a sealed reaction chamber, the liquid carbon dioxide phase change module includes liquid carbon dioxide located in the sealed reaction chamber, and the deflagration suspended powder module includes suspended powder suspended in liquid carbon dioxide.

[0009] Preferably, the constant pressure energy release module includes a constant pressure shear plate, an energy release port, and a spiral pressure ring. The constant pressure shear plate is located at the annular shoulder at the bottom end of the fracturing tube. Rubber sealing gaskets are provided on both sides of the constant pressure shear plate. The constant pressure shear plate is pre-tightened by the spiral pressure ring. The energy release port is connected to the constant pressure shear plate.

[0010] Preferably, the high-voltage energy storage module includes high-voltage energy storage, a high-voltage energy storage control panel, a high-voltage power output line, and internal insulation. One end of the high-voltage power output line is electrically connected to the high-voltage energy storage, and the other end of the high-voltage power output line is electrically connected to the switch module. The internal insulation is located between the high-voltage energy storage and the pulse excitation module.

[0011] Preferably, the pulse excitation module includes a capacitor bank, a high-voltage electrode, and a ground electrode. The capacitor bank includes several high-voltage pulse capacitors connected in series or in parallel. One end of the high-voltage electrode is electrically connected to the positive electrode of the capacitor bank, and the other end of the high-voltage electrode is electrically connected to the electro-explosion excitation unit of the fracturing tube via a cable.

[0012] Preferably, the switch module includes a switch metal housing, an upper switch insulation, a lower switch insulation, an upper switch electrode, a lower switch electrode, and a gas filling / discharging assembly. The upper and lower switch insulations are located on opposite sides of the switch metal housing. The upper switch electrode is located on one side of the upper switch insulation, and the lower switch electrode is located on the side of the lower switch insulation. The gas filling / discharging assembly includes a nitrogen cylinder with a gas filling valve connected to it. The gas filling valve is connected to a cavity inside the switch metal housing via a gas filling line, and a gas venting valve is connected to the cavity inside the switch metal housing via a gas venting line.

[0013] Preferably, the electro-explosion excitation unit includes an external electrode located inside the fracturing tube and a metal wire connected to the external electrode, wherein the external electrode is electrically connected to the high-voltage electrode.

[0014] Preferably, the rock block to be detonated is located on the experimental operating table, and a high-pressure gas cylinder containing liquid carbon dioxide is provided on one side of the experimental operating table. The high-pressure gas cylinder is connected to a liquid delivery line, and the end of the liquid delivery line away from the high-pressure gas cylinder is located in the sealed reaction chamber. A booster pump is installed on the liquid delivery line.

[0015] The present invention discloses the following technical effects: This invention utilizes a triple energy coupling mechanism of electro-explosive impact, suspended powder deflagration, and liquid carbon dioxide phase change expansion to form a progressive fracturing mechanism: transient strong impact initiation, chemical energy-enhanced fracture expansion, and sustained high-pressure gas propagation. Compared to traditional liquid carbon dioxide phase change fracturing and simple electro-explosive rock breaking, this system not only rapidly forms an initial fracture network in high-strength, low-defect rock masses through the high strain rate loads of electro-explosion and powder deflagration, but also relies on the sustained high pressure of carbon dioxide phase change to drive the directional extension of fractures, thus solving the problems of "difficulty in initiating fractures" and "difficulty in propagating fractures" in non-explosive fracturing techniques. Addressing the dual challenges of "weakness," this method improves rock-breaking efficiency. Electro-explosive impact and suspended powder deflagration provide high strain rate loads, facilitating the formation of initial fractures in high-strength, low-initial-defect rock masses. The high-pressure gas generated by the phase change of liquid carbon dioxide provides continuous driving force, allowing for directional propagation along the initial fractures to form extended fractures, thus improving fracture controllability. It does not rely on traditional explosives, offering high safety and environmental friendliness, and can be used in sensitive areas. Multiple operating conditions can be matched by adjusting the charging energy, liquid carbon dioxide filling amount, powder type and dosage, shear plate breaking threshold, and energy release port structure. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the composite fracturing and rock-breaking system of the present invention; Figure 2 This is a schematic diagram of the high-voltage pulse device of the present invention; Figure 3 This is a schematic diagram of the rupture tube structure of the present invention; Figure 4 This is a schematic diagram of the mechanism from impact initiation to phase transformation and propagation stages of the present invention; Among them, 1. High-voltage pulse device; 102. Upper electrode of switch; 103. Upper insulation of switch; 104. Lower insulation of switch; 105. Lower electrode of switch; 106. Metal casing of switch; 108. High-voltage output line of power supply; 109. Capacitor group; 110. High-voltage pulse capacitor; 112. Internal insulation of device; 113. High-voltage energy storage; 114. High-voltage energy storage control panel; 115. Gas charging valve; 116. Gas charging line; 117. Gas venting line; 118. Gas venting valve; 2. Fracturing tube; 202. External electrode; 204. Metal wire; 205. Sealed reaction chamber; 206. Liquid carbon dioxide; 207. Suspended powder; 208. Constant pressure shear plate; 209. Energy release port; 4. Rock block to be detonated; 5. Booster pump; 6. Experimental operating table; 7. High-pressure gas cylinder; 8. Nitrogen gas cylinder; 9. Infusion line. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Reference Figures 1-4 This invention provides an electrically ignited liquid CO2 powder suspension phase change impact composite rock-breaking system, including... The high-voltage pulse device 1 includes a high-voltage energy storage module, a pulse excitation module, and a switching module. The high-voltage energy storage module is used to provide a controllable high-voltage DC output to charge and store energy for the pulse excitation module. The pulse excitation module is used to store electrical energy and release it to form a pulse when triggered. The switching module is used to rapidly release the energy stored in the capacitor into a high-voltage pulse when the triggering conditions are met. The fracturing tube 2 is equipped with a liquid carbon dioxide phase change module, a deflagration suspended powder module and a constant pressure energy release module; an electric explosion excitation unit is set at the top of the fracturing tube 2, and the liquid carbon dioxide phase change module and the deflagration suspended powder module are electrically connected to the high-voltage pulse device 1 through the electric explosion excitation unit. Liquid carbon dioxide and suspended powder are mainly placed inside the fracturing tube tank. The top of the tube is equipped with a filling port and two external electrodes. The two external electrodes are located inside the fracturing tube and are connected by metal wires. The two external electrodes are connected to the external electrodes of the high-voltage pulse device to release pulse current. The deflagration of the metal wire generates plasma. The high temperature and high pressure generated in this process induce deflagration of the suspended powder and phase change of liquid carbon dioxide. Furthermore, the fracturing tube 2 is made of high-strength metal or other materials, and can withstand the combined high-energy impact loads generated by the electric explosion impact, the deflagration of suspended powder 207, and the phase change of liquid carbon dioxide 206.

[0021] A rock block 4 is to be detonated, with a drilled hole at its center. A fracturing tube 2 is located inside the drilled hole. The gap between the wall of the fracturing tube 2 and the borehole wall is sealed with epoxy resin to prevent energy leakage. This prevents the tube from flying off during the explosion and also seals the top to prevent energy leakage.

[0022] Further optimizing the design, a sealed reaction chamber 205 is provided inside the fracturing tube 2. This chamber contains liquid carbon dioxide 206, suspended powder 207, and an electro-explosion activation unit, enabling energy accumulation, superposition, and controlled release during fracturing. The liquid carbon dioxide phase change module includes liquid carbon dioxide 206 located within the sealed reaction chamber 205. As a phase change medium, liquid carbon dioxide 206 undergoes a rapid phase change from liquid to gas under heating conditions, providing continuous gas expansion energy for the system. The deflagration suspended powder module includes suspended powder 207 suspended in the liquid carbon dioxide. Suspended powder 207 is disposed within a sealed reaction chamber 205 and dispersed in liquid carbon dioxide 206. By suspending the powder within the liquid carbon dioxide 206, it can fully participate in the reaction process during electro-explosion. The suspended powder 207 is a flammable powder such as aluminum powder, aluminum alloy powder, or magnesium powder. Through a filling process, the suspended powder 207 is filled in the liquid carbon dioxide 206 in a suspended or semi-suspended distribution, making it easier to ignite and undergo a deflagration reaction in the high temperature, high pressure, and plasma environment generated by the electro-explosion. The suspended powder 207 is used to release chemical energy through deflagration, increasing the pressure rise rate and peak pressure within the sealed reaction chamber 205. After the electro-explosion impact, the suspended powder 207 deflagrates, releasing a large amount of heat, and the liquid carbon dioxide 206 undergoes a phase change, continuously providing energy output, making the crack initiation stage more complex and enhancing the high-pressure gas driving capability during the propagation stage.

[0023] Furthermore, the suspended powder 207 can be selected with different particle sizes or mixed particle sizes to adjust the deflagration rate.

[0024] Further optimization of the scheme: the constant pressure energy release module includes a constant pressure shear plate 208, an energy release port 209, and a spiral pressure ring. The constant pressure shear plate 208 is located at the annular shoulder at the bottom of the fracturing tube 2. The constant pressure shear plate 208 is used to limit the maximum pressure bearing value of the sealed reaction chamber 205, so that the sealed reaction chamber 205 remains sealed before the pressure reaches a predetermined threshold, which facilitates the superposition of electric explosion energy, suspended powder 207 deflagration energy, and liquid carbon dioxide 206 phase change energy within the chamber. When the pressure inside the sealed reaction chamber 205 reaches the breaking threshold of the constant pressure shear plate 208, the constant pressure shear plate 208 breaks, and the energy accumulated in the chamber is released into the rock mass through the energy release port 209. Rubber sealing gaskets are provided on both sides of the constant pressure shear plate 208. The constant pressure shear plate 208 is pre-tightened by the spiral pressure ring, and the energy release port 209 is connected to the constant pressure shear plate 208. The constant-pressure shear plate 208 is used to limit the pressure threshold of the sealed reaction chamber 205, allowing energy to accumulate in a closed manner before reaching the preset conditions. When the threshold is reached, the constant-pressure shear plate 208 breaks, and the high-temperature and high-pressure medium is released directionally through the energy release port 209, thereby achieving rock breaking and directional fracturing. The energy release port 209 has a unidirectional or multidirectional structure, and the nozzle direction, number, and angle can be set according to the directional fracturing requirements to achieve directional fracturing induction in the direction of fracture propagation.

[0025] The breaking pressure of the constant-pressure shear plate 208 is designed to withstand the instantaneous impact of an electric explosion shock wave without damage. Although the peak pressure of the electric explosion shock is high, its duration is extremely short, on the order of microseconds. The pressure impulse generated on the constant-pressure shear plate 208 is insufficient to cause damage. Meanwhile, the pressure generated by the phase change of liquid carbon dioxide 206 is a continuously rising quasi-static high pressure. When the breaking threshold of the constant-pressure shear plate 208 is reached, the constant-pressure shear plate 208 fails. This design ensures that the electric explosion shock is preferentially used for crack initiation, while the phase change expansion energy and the deflagration energy of the suspended powder 207 are released only after sufficient accumulation, thus achieving temporal decoupling and synergistic utilization of the three energies. The breaking pressure of the constant-pressure shear plate 208 can be adjusted by means of materials, thickness, and prefabricated groove structure to meet the sequence of crack initiation, crack propagation, and energy release.

[0026] Furthermore, the energy release port 209 can achieve directional fracturing with a single nozzle or form a directional fracture network with multiple nozzles.

[0027] The design is further optimized. The high-voltage energy storage module includes a high-voltage energy storage unit 113, a high-voltage energy storage control panel 114, a high-voltage power output line 108, and internal insulation 112. One end of the high-voltage power output line 108 is electrically connected to the high-voltage energy storage unit 113, and the other end is electrically connected to the switching module. The internal insulation 112 is located between the high-voltage energy storage unit 113 and the pulse excitation module. The high-voltage energy storage control panel 114 is used for setting charging parameters, monitoring status, and remote control.

[0028] Further optimization of the scheme: the pulse excitation module includes a capacitor bank 109, a high-voltage electrode and a ground electrode. The capacitor bank 109 includes several high-voltage pulse capacitors 110 connected in series or in parallel. One end of the high-voltage electrode is electrically connected to the positive electrode of the capacitor bank 109, and the other end of the high-voltage electrode is electrically connected to the electric explosion excitation unit of the fission tube 2 through a cable.

[0029] Further optimization of the scheme: The switch module includes a switch metal housing 106, an upper switch insulator 103, a lower switch insulator 104, an upper switch electrode 102, a lower switch electrode 105, and a charging / discharging assembly. The upper switch insulator 103 and the lower switch insulator 104 are located on opposite sides of the switch metal housing 106. The upper switch electrode 102 is located on one side of the upper switch insulator 103, and the lower switch electrode 105 is located on the side of the lower switch insulator 104. The charging / discharging assembly includes a nitrogen cylinder 8, with a charging valve 115 connected to the nitrogen cylinder 8. The charging valve 115 is connected to the cavity inside the switch metal housing 106 via a charging line 116. The cavity inside the switch metal housing 106 is connected to a venting valve 118 via a venting line 117. A discharge gap is formed between the upper switch electrode 102 and the lower switch electrode 105. The charging / discharging assembly enables reliable triggering. By adjusting the gas pressure inside the switch cavity, the withstand voltage characteristics of the discharge gap are changed, causing breakdown discharge under set conditions, thereby outputting a high-voltage pulse.

[0030] Furthermore, it is equipped with an electrode-to-multiple-transfer device and multiple cable interfaces to achieve single or multiple synchronous pulse outputs, in order to meet engineering requirements such as single-hole or multi-hole cracking and directional cutting.

[0031] Further optimizing the scheme, the electro-explosion excitation unit includes an external electrode 202 located inside the fracturing tube 2 and a metal wire 204 connected to the external electrode 202. The external electrode 202 is electrically connected to the high-voltage electrode. The metal wire 204 is located on the axis of the sealed reaction chamber 205 and is immersed in liquid carbon dioxide 206. When a high-voltage pulse is applied, the metal wire 204 undergoes an electro-explosion process of Joule heating, melting, and plasmaization, generating an electro-explosion shock wave and a high-temperature environment, providing triggering conditions for the formation of initial fractures and the deflagration of suspended powder 207. The electro-explosion of the metal wire 204 and the deflagration of the suspended powder 207 form initial fractures in the rock mass, and the high-pressure gas generated by the phase transformation of liquid carbon dioxide 206 extends along the initial fractures to form extended fractures.

[0032] Furthermore, the metal wire 204 can be tungsten wire, copper wire, or alloy wire. Its electrical explosion characteristics can be optimized by adjusting its diameter and length.

[0033] Further optimizing the scheme, the rock block 4 to be detonated is located on the experimental operating platform 6. A high-pressure gas cylinder 7 containing liquid carbon dioxide 206 is placed on one side of the platform. The high-pressure gas cylinder 7 is connected to a liquid delivery line 9. The end of the liquid delivery line 9 furthest from the high-pressure gas cylinder 7 is located inside the sealed reaction chamber 205. A booster pump 5 is installed on the liquid delivery line 9. Liquid carbon dioxide 206 is filled through the high-pressure gas cylinder 7 and the booster pump 5. After filling, the sealed reaction chamber 205 is in a sealed state. Under the action of the heat energy released by the electric explosion and the deflagration of the suspended powder 207, the liquid carbon dioxide 206 undergoes a rapid phase change expansion from liquid to gas, generating high-pressure gas. This high-pressure gas provides continuous pressurization during the unbroken stage of the constant-pressure shear plate 208, and provides continuous propulsion along the fracture after the initial fracture is formed.

[0034] In laboratory applications, experimental rock blocks 4 are first prepared, holes are drilled in the rock blocks 4, and then the fracturing tube 2 is placed in the drilled holes. The gap between the fracturing tube 2 and the drilled holes is sealed with epoxy resin. The inside of the fracturing tube 2 is a closed reaction chamber 205. The fracturing tube 2 can be made of high-strength metal materials or composite materials to withstand the combined pressure loads generated by the electric explosion impact, the deflagration of suspended powder 207 and the phase change of liquid carbon dioxide 206.

[0035] Experimental procedure of this invention: 1. Before the experiment, prepare 4 rock blocks to be detonated. Take the complete bottom rock block of the target and cut the rock core into cubic samples of 500mm x 500mm x 260mm, ensuring that the parallelism of the end face is ≤0.05mm and the surface roughness is ≤3.2um. Use a CNC core drilling machine to drill a coaxial hole at the geometric center of the rock core, with a hole diameter of Φ50mm and a hole depth of 195mm. The bottom end face of the hole and the bottom end face of the rock core retain a complete thickness of 65mm ± 1mm ​​to ensure that the subsequent fracturing energy is fully applied to the surrounding rock.

[0036] 2. Assemble the fracturing tube 2. Embed the constant pressure shear plate 208 into the annular shoulder of the lower connector of the fracturing tube 2. Apply rubber sealing gaskets to both the upper and lower sides of the constant pressure shear plate 208 to form a double-sided line seal, ensuring zero leakage of the shear plate below the set rupture pressure. Screw the spiral pressure ring into the lower connector of the tube body. The end face of the spiral pressure ring maintains a 5mm interference fit with the outer edge of the constant pressure shear plate 208, which provides axial preload and prevents the constant pressure shear plate 208 from shearing prematurely. The upper end cap is equipped with three channels: the center is the liquid carbon dioxide filling port, and the two sides are high-voltage electrode inlets. The electrode pins are sealed with casting adhesive between them and the end cap. The two electrodes are connected by metal wire 204 to form an electro-explosion activation unit. After assembly, connect the upper end cap to the liquid storage tube body with high-strength threads and tighten with a torque wrench. After completion, perform a pressure holding test at 1.5 times the design pressure. A pressure drop ≤ 0.5MPa is considered acceptable for air tightness.

[0037] 3. The assembled fracturing tube 2 is vertically inserted into the bottom of the borehole, with the flange at the tube end protruding 10mm above the end face of the rock block 4 to be detonated, for connecting the external high-voltage electrode and the liquid filling channel; the annular gap between the outer wall of the fracturing tube 2 and the borehole wall is sealed with epoxy resin and cured at 20℃ for 24 hours. The epoxy resin, the rock block 4 to be detonated, and the wall of the fracturing tube 2 form an integrated high-pressure sealing layer. The measured pressure bearing capacity of the annular gap seal is ≥100MPa, which meets the requirement of no lateral leakage during subsequent liquid carbon dioxide phase change blasting.

[0038] 4. After the bonded sample passes inspection, inject suspended powder 207 through the filling port, and then fill with liquid carbon dioxide at a rate of 0.8 to 1.2 MPa / min. During the filling process, the rupture tube 2 is tilted back and forth twice to make the powder evenly dispersed by turbulence. After filling to the target filling rate of 75 to 85%, close the needle valve.

[0039] 5. After completing the above preparations, the high-voltage pulse power supply is first charged. Once the predetermined test value is reached, a pulse current is applied to the metal wire 204 through the high-voltage pulse power supply. The metal wire 204 undergoes an electrical explosion within 2-5 μs, forming a plasma channel and generating a shock wave. This is the first level of energy. The plasma radiation and high-temperature bombardment trigger the deflagration of the suspended powder 207, releasing additional energy and causing the local pressure to continue to rise. This is the second level of energy. The heat released by the electrical explosion plasma impact heats the surrounding liquid carbon dioxide, causing it to instantly enter a supercritical state. When the pressure inside the tube reaches the rupture threshold set by the shear plate, the constant-pressure shear plate 208 shears and destroys the entire circle along the precast groove. The generated high-pressure gas is ejected at high speed through the bidirectional energy release port 209 within 0.2-2 ms, generating an expansion pressure of 200-400 MPa. This pressure exerts a continuous pushing effect on the initial crack, forming an expanding crack, thereby achieving crack length growth, crack interconnection, or directional extension. This is the third level of energy. Figure 4 The diagram illustrates the effects of impact-induced fracturing and phase transformation-induced fracturing. The three energies are coupled sequentially to achieve a synergistic rock-breaking effect.

[0040] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0041] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An electrically ignited liquid CO2 powder suspension phase change impact composite rock-breaking system, characterized in that: include A high-voltage pulse device (1) includes a high-voltage energy storage module, a pulse excitation module, and a switching module. The high-voltage energy storage module is used to provide a controllable high-voltage DC output to charge and store energy for the pulse excitation module. The pulse excitation module is used to store electrical energy and release it to form a pulse when triggered; The switching module is used to rapidly release the energy stored in the capacitor as a high-voltage pulse when the triggering conditions are met; The fracturing tube (2) is equipped with a liquid carbon dioxide phase change module, a deflagration suspended powder module and a constant pressure energy release module; an electric explosion excitation unit is provided at the top of the fracturing tube (2); the liquid carbon dioxide phase change module and the deflagration suspended powder module are electrically connected to the high-voltage pulse device (1) through the electric explosion excitation unit. A rock block to be detonated (4) has a drill hole in its center, and the fracturing tube (2) is located inside the drill hole.

2. The electrically ignited liquid CO2 powder suspension phase change impact composite rock-breaking system according to claim 1, characterized in that: The cracking tube (2) has a closed reaction chamber (205) inside. The liquid carbon dioxide phase change module includes liquid carbon dioxide (206) located in the closed reaction chamber (205). The deflagration suspended powder module includes suspended powder (207) suspended in liquid carbon dioxide.

3. The electrically ignited liquid CO2 powder suspension phase change impact composite rock-breaking system according to claim 1, characterized in that: The constant pressure energy release module includes a constant pressure shear plate (208), an energy release port (209), and a spiral pressure ring. The constant pressure shear plate (208) is located at the annular shoulder at the bottom end of the fracturing tube (2). Rubber sealing gaskets are provided on both sides of the constant pressure shear plate (208). The constant pressure shear plate (208) is pre-tightened by the spiral pressure ring. The energy release port (209) is connected to the constant pressure shear plate (208).

4. The electrically ignited liquid CO2 powder suspension phase change impact composite rock-breaking system according to claim 1, characterized in that: The high-voltage energy storage module includes a high-voltage energy storage (113), a high-voltage energy storage control panel (114), a high-voltage power output line (108), and internal insulation (112). One end of the high-voltage power output line (108) is electrically connected to the high-voltage energy storage (113), and the other end of the high-voltage power output line (108) is electrically connected to the switch module. The internal insulation (112) is located between the high-voltage energy storage (113) and the pulse excitation module.

5. The electrically ignited liquid CO2 powder suspension phase change impact composite rock-breaking system according to claim 1, characterized in that: The pulse excitation module includes a capacitor bank (109), a high-voltage electrode and a ground electrode. The capacitor bank (109) includes several high-voltage pulse capacitors (110) connected in series or in parallel. One end of the high-voltage electrode is electrically connected to the positive electrode of the capacitor bank (109), and the other end of the high-voltage electrode is electrically connected to the electro-explosion excitation unit of the fission tube (2) through a cable.

6. The electrically ignited liquid CO2 powder suspension phase change impact composite rock-breaking system according to claim 1, characterized in that: The switch module includes a switch metal housing (106), an upper switch insulation (103), a lower switch insulation (104), an upper switch electrode (102), a lower switch electrode (105), and a gas filling / draining assembly. The upper switch insulation (103) and the lower switch insulation (104) are located on opposite sides of the switch metal housing (106). The upper switch electrode (102) is located on one side of the upper switch insulation (103), and the lower switch electrode (105) is located on the side of the lower switch insulation (104). The gas filling / draining assembly includes a nitrogen cylinder (8). A gas filling valve (115) is connected to the nitrogen cylinder (8). The gas filling valve (115) is connected to the cavity inside the switch metal housing (106) through a gas filling line (116). The cavity inside the switch metal housing (106) is connected to a gas venting valve (118) through a gas venting line (117).

7. The electrically ignited liquid CO2 powder suspension phase change impact composite rock-breaking system according to claim 5, characterized in that: The electro-explosion excitation unit includes an external electrode (202) located inside the fracturing tube (2) and a metal wire (204) connected to the external electrode (202). The external electrode (202) is electrically connected to the high-voltage electrode.

8. The electrically ignited liquid CO2 powder suspension phase change impact composite rock-breaking system according to claim 2, characterized in that: The rock block to be detonated (4) is located on the experimental operating table (6). A high-pressure gas cylinder (7) containing liquid carbon dioxide (206) is set on one side of the experimental operating table (6). The high-pressure gas cylinder (7) is connected to a liquid delivery line (9). The end of the liquid delivery line (9) away from the high-pressure gas cylinder (7) is located in the sealed reaction chamber (205). A booster pump (5) is installed on the liquid delivery line (9).

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