CN112762781A - Rock breaking device and method for open-pit mine under combined action of transient static gas fracturing - Google Patents

Abstract

A rock breaking device and a method for strip mine under the combined action of transient static gas fracturing, wherein the device comprises a gas pressurization system, an energy accumulator, a fracturing chamber, a packer and a gas injection pipe; a pressure sensor, a flow sensor and a plurality of valves are arranged in the gas pressurization system and on the gas injection pipe, and the plurality of gas pressurization systems are arranged in parallel; the side wall of the fracturing chamber is provided with a fracturing hole, and the packer is positioned in an annular space between the fracturing chamber on the upper side and the lower side of the fracturing hole and the inner hole wall of the drill hole. The energy storage device is arranged in parallel with the gas pressurization system. The method comprises the following steps: arranging holes; drilling; sending the fracturing chamber equipped with the packer into a borehole; inflating the annular packing air bag of the packer, and finishing packing by the expanded annular packing air bag; starting a gas pressurization system, selecting proper fracturing gas to be injected into the drill hole, and performing transient and static fracturing processes in a reciprocating manner to enable an ore body to generate fatigue and generate a complex fracture network so as to realize ore body destruction; recovering waste gas and releasing pressure; and (5) exhausting the annular packing air bag to finish unpacking.

Description

Rock breaking device and method for open-pit mine under combined action of transient static gas fracturing

Technical Field

The invention belongs to the technical field of strip mine exploitation, and particularly relates to a rock breaking device and method for strip mine under combined action of transient static gas fracturing.

Background

Strip mining is a process of removing a covering on an ore body to obtain required minerals, generally comprising the operation processes of stripping, blasting, mining, loading and the like, wherein the blasting process is a key link influencing the mining quality, safety and economic benefit of the ore body. The traditional blasting mode utilizes the explosive gas that explodes produced of explosive in drilling to reach the purpose that sends and splits the rock, but traditional blasting mode exists a great deal of potential safety hazard, and the explosive easily causes the incident in storage, transportation, and the explosive can arouse great air shock wave when using, not only can bring noise, environmental pollution, and great seismic wave still can influence the slope stability moreover, and then has brought serious secondary disaster. In addition, high-temperature explosive gas is easy to lose coal bodies in the drill holes in the blasting process of open-pit coal mining, and a large amount of resources are wasted.

Therefore, the carbon dioxide blasting and high-energy gas fracturing technologies are produced at the same time, and although the rock breaking effect of the carbon dioxide blasting and high-energy gas fracturing technologies is obvious, the characteristics of integrity and single action on an ore body exist because the blasting mode of a detonator explosive is required, and the quality of mineral resources can be influenced if the single action effect and the integral action effect are required to be improved and the shock wave strength is required to be increased. In addition, the two blasting modes need to prepare the blasting cartridge in advance, the volume in the blasting cartridge is quantitative, the pressure control and adjustment cannot be carried out in the blasting process, and the large potential safety hazard exists, and the safety accidents caused by the blasting cartridge are frequent.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a rock breaking device and method for strip mine under the combined action of transient static gas fracturing, which combines the transient gas fracturing technology and the static gas fracturing technology to be applied to strip mine exploitation, realizes dynamic regulation and control of rock breaking energy in the blasting process, and solves the technical problems of high risk, uncontrollable pressure, poor blasting effect and the like in the traditional explosive blasting technology and the traditional high-energy gas fracturing technology.

In order to achieve the purpose, the invention adopts the following technical scheme: a rock breaking device for strip mines under the combined action of transient static gas fracturing comprises a gas pressurization system, an energy accumulator, a fracturing chamber, a packer and a gas injection pipe; the number of the gas pressurization systems is a plurality, and the gas pressurization systems are arranged in parallel; the gas pressurization system and the energy storage device are positioned outside the drill hole; the fracturing chamber is positioned inside the drill hole; a cracking hole is formed in the side wall of the cracking chamber, and the inner cavity of the cracking chamber is communicated with the drill hole through the cracking hole; the packer is arranged in an annular space between the fracturing chambers on the upper side and the lower side of the fracturing hole and the inner hole wall of the drill hole; the gas pressurization system is output in two paths, the first path is communicated with the inner cavity of the fracturing chamber through a gas injection pipe, and the second path is communicated with the packer through the gas injection pipe; and the gas injection pipe for communicating the gas pressurization system with the cracking chamber is connected with the energy accumulator in parallel.

The cracking chamber can adopt a single-stage structure or a multi-stage series structure; when the fracturing chamber adopts a single-stage structure, the upper and lower end openings of the fracturing chamber are respectively plugged by a top plug and a bottom plug; when the cracking chambers adopt a multistage series structure, the upper end barrel openings of the first-stage cracking chambers are plugged through the top plugs, the adjacent cracking chambers are connected in series in a screwing mode, and the lower end barrel openings of the first-stage cracking chambers are plugged through the bottom plugs.

The gas pressurization systems arranged in parallel are intersected with a first tee joint, and a first pressure sensor, a first flow sensor, a first valve, a second tee joint, a second valve, a third tee joint, a first four-way joint and a third valve are sequentially arranged on a gas injection pipe between the first tee joint and the fracturing chamber; the air inlet end of the energy accumulator is communicated with the second tee joint, and a fourth valve is arranged on a pipeline between the air inlet end of the energy accumulator and the second tee joint; the gas outlet end of the energy accumulator is communicated with the third tee joint, and a second pressure sensor, a second flow sensor and a fifth valve are sequentially arranged on a pipeline between the gas outlet end of the energy accumulator and the third tee joint; and a waste gas storage tank is arranged outside the drill hole, the air inlet end of the waste gas storage tank is communicated with the first four-way joint, and a third pressure sensor and a sixth valve are sequentially arranged on a pipeline between the air inlet end of the waste gas storage tank and the first four-way joint.

The gas pressurization system comprises an air compressor, an air storage tank, a nitrogen making machine, a nitrogen storage tank, a liquid nitrogen storage tank, a carbon dioxide storage tank and a heater; the air outlet end of the air compressor is communicated with the first tee joint, and a fourth pressure sensor, a fourth tee joint, a seventh valve, a second tee joint, a first booster pump, a fifth pressure sensor, a third flow sensor, an eighth valve, a second booster pump, a sixth pressure sensor, a fourth flow sensor and a ninth valve are sequentially arranged on a pipeline between the air outlet end of the air compressor and the first tee joint; the air inlet end of the air storage tank is communicated with the fourth tee joint, and a tenth valve is arranged on a pipeline between the air inlet end of the air storage tank and the fourth tee joint; an air outlet end of the air storage tank is communicated with an air inlet end of the nitrogen making machine, and an eleventh valve is arranged on a pipeline between the air outlet end of the air storage tank and the air inlet end of the nitrogen making machine; the gas outlet end of the nitrogen making machine is communicated with the gas inlet end of the nitrogen storage tank, and a twelfth valve is arranged on a pipeline between the gas outlet end of the nitrogen making machine and the gas inlet end of the nitrogen storage tank; the gas outlet end of the nitrogen storage tank is communicated with the second four-way joint, and a thirteenth valve and a fifth three-way joint are sequentially arranged on a pipeline between the gas outlet end of the nitrogen storage tank and the second four-way joint; the liquid outlet end of the liquid nitrogen storage tank is communicated with the fifth tee joint, and a fourteenth valve is arranged on a pipeline between the liquid outlet end of the liquid nitrogen storage tank and the fifth tee joint; the gas outlet end of the carbon dioxide storage tank is communicated with the feed end of the heater, and a sixth tee joint and a fifteenth valve are sequentially arranged on a pipeline between the gas outlet end of the carbon dioxide storage tank and the feed end of the heater; the discharge end of the heater is communicated with the second four-way joint, and a sixteenth valve and a seventh three-way joint are sequentially arranged on a pipeline between the discharge end of the heater and the second four-way joint; the sixth tee joint and the seventh tee joint are communicated through a straight pipeline, and a seventeenth valve is arranged on the straight pipeline.

In one set of the gas pressurization system, an eighth tee joint is further arranged on a pipeline between the third flow sensor and the eighth valve, and an eighteenth valve, a pressure reducing valve, a nineteenth valve, a ninth tee joint and a tenth tee joint are sequentially arranged on a gas injection pipe between the eighth tee joint and the packer; the thirteenth pipeline is divided into two paths and communicated with the packer, a twentieth valve is arranged on the first path of pipeline of the tenth pipeline and the packer, and a twenty-first valve is arranged on the second path of pipeline of the tenth pipeline and the packer; the tenth tee is communicated with the first four-way, and a twelfth valve is arranged on a pipeline between the tenth tee and the first four-way.

The packer comprises an annular bearing base, a gas injection central pipe column, an annular packing air bag and a high-pressure closed spray head; the annular bearing base is fixedly sleeved outside the fracturing chamber, the gas injection central pipe column is fixedly inserted in the annular bearing base, and the gas injection central pipe column is communicated with the gas injection pipe; the annular packing air bag is sleeved on the circumferential outer side of the annular bearing base, and the annular packing air bag is communicated with the gas injection pipe through a high-pressure closed nozzle; and a thrust spring is coaxially arranged on the inner side of the central orifice of the high-pressure closed nozzle, one end of the thrust spring is connected with the high-pressure closed nozzle, and the other end of the thrust spring is connected with a nozzle sealing plate.

A seventh pressure sensor is arranged on the wall of the fracturing chamber between the packers at the upper side and the lower side of the fracturing hole, and a sensor signal adapter is arranged at the upper part of the wall of the fracturing chamber; the drilling outside is provided with information collection station and computer, first pressure sensor, second pressure sensor, third pressure sensor, fourth pressure sensor, fifth pressure sensor, sixth pressure sensor, seventh pressure sensor, first flow sensor, second flow sensor, third flow sensor and fourth flow sensor's signal output part all carries out the electricity with information collection station and is connected, seventh pressure sensor's signal output part carries out the electricity through sensor signal adapter and information collection station and is connected, and information collection station's signal output part carries out the electricity with the computer and is connected.

A rock breaking method for the combined action of transient static gas fracturing for strip mines adopts a rock breaking device for the combined action of transient static gas fracturing for strip mines, and comprises the following steps:

the method comprises the following steps: determining the hole distribution position and the hole distribution quantity of the drill holes according to the mining requirement of the strip mine;

step two: drilling holes at the determined hole distribution positions by using drilling equipment until the drilling holes reach a preset depth;

step three: sending the fracturing chamber with the packer into a drill hole;

step four: the seventh valve, the eighth valve, the ninth valve, the eighteenth valve, the nineteenth valve, the twentieth valve and the twenty-first valve are adjusted to be in an opening state, the rest valves are maintained in a closing state, the air compressor is started simultaneously, compressed air is firstly pressurized by the first booster pump, then flows through the pressure reducing valve and enters the air injection central pipe column, the compressed air after being regulated by the pressure reducing valve flows out of the air injection central pipe column and directly enters the annular packing air bag, the nozzle sealing plate is in an opening state at the moment, the compressed air can smoothly pass through the high-pressure closed nozzle to enable the annular packing air bag to be gradually inflated and expanded until the expanded annular packing air bag is tightly attached to the inner hole wall of the drill hole, the pressure in the high-pressure closed nozzle is gradually increased along with the continuous injection of the compressed air, and when the pressure exceeds the spring force of the thrust spring, the nozzle sealing plate is, then the high-pressure closed spray head is closed, the annular packing air bag is inflated, the annular space of the drill holes on the upper side and the lower side of the fractured hole is packed, an annular packing section is formed, all opened valves are quickly closed, and the air compressor and the first booster pump are closed simultaneously;

step five: starting a gas pressurization system, and dividing the gas pressurization system into the following five operation modes according to different fracturing gases:

transient and static fracturing based on air

Step 1: the seventh valve, the eighth valve, the ninth valve, the first valve, the fourth valve, the fifth valve and the third valve are adjusted to be in an opening state, the rest valves are maintained in a closing state, an air compressor is started simultaneously, compressed air is firstly subjected to primary pressurization through the first booster pump, then secondary pressurization is carried out through the second booster pump, the compressed air after the secondary pressurization is finished directly enters the energy accumulator, after the pressure in the energy accumulator reaches a set value, high-pressure air is released by the energy accumulator, the high-pressure air sequentially passes through the fracturing chamber inner cavity and the fracturing hole to enter the annular sealing section of the drill hole, and the ore body is fractured through transient high pressure;

step 2: closing the fourth valve and the fifth valve, opening the second valve, simultaneously maintaining the opening states of the seventh valve, the eighth valve, the ninth valve, the first valve and the third valve, directly injecting compressed air subjected to two-stage pressurization into the inner cavity of the fracturing chamber and the annular sealing section of the drill hole, and further fracturing an ore body through static high pressure to expand the fracture;

step 3; repeating the step 1 and the step 2, and performing transient and static fracturing processes repeatedly to enable the ore body to generate fatigue, further enable the ore body to generate a complex fracture network and finally realize the damage of the ore body;

② static fracturing based on liquid nitrogen

The fourteenth valve, the eighth valve, the ninth valve, the first valve, the second valve and the third valve are adjusted to be in an opening state, the rest valves are maintained in a closing state, a liquid nitrogen storage tank is opened, output liquid nitrogen is firstly subjected to primary pressurization through the first booster pump and then subjected to secondary pressurization through the second booster pump, the pressurized liquid nitrogen is directly injected into an inner cavity of the fracturing chamber and a circumferential sealing section of a drill hole, the liquid nitrogen is gasified to absorb a large amount of heat and form low-temperature gas, so that a cold impact effect is generated on an ore body, the brittleness of the ore body is increased, along with continuous injection of the liquid nitrogen, high-pressure gas formed after gasification and expansion of the liquid nitrogen also acts on the ore body, and the ore body can generate a complex fracture network under repeated actions of cold impact and high pressure, and finally the damage of the ore body is realized;

transient and static fracturing based on nitrogen

Step 1: the tenth valve, the eleventh valve, the twelfth valve, the thirteenth valve, the eighth valve, the ninth valve, the first valve, the fourth valve, the fifth valve and the third valve are adjusted to be in an opening state, the other valves are maintained in a closing state, simultaneously starting the air compressor, leading the compressed air to enter the air storage tank firstly, then leading the compressed air to flow into the nitrogen making machine from the air storage tank, then leading the nitrogen making machine to output nitrogen and injecting the nitrogen into the nitrogen storage tank, then nitrogen output by the nitrogen storage tank is subjected to primary pressurization through a first booster pump, then secondary pressurization is carried out through a second booster pump, the nitrogen after the secondary pressurization directly enters an energy accumulator, when the pressure in the energy accumulator reaches a set value, releasing high-pressure nitrogen by the energy accumulator, sequentially passing the high-pressure nitrogen through the inner cavity of the fracturing chamber and the fracturing hole to enter the annular sealing section of the drilled hole, and fracturing an ore body by transient high pressure;

step 2: closing the fourth valve and the fifth valve, opening the second valve, simultaneously maintaining the opening states of the tenth valve, the eleventh valve, the twelfth valve, the thirteenth valve, the eighth valve, the ninth valve, the first valve and the third valve, directly injecting nitrogen after secondary pressurization into the inner cavity of the fracturing chamber and the annular sealing section of the drill hole, and further fracturing an ore body through static high pressure to expand the fracture;

step 3; repeating the step 1 and the step 2, and performing transient and static fracturing processes repeatedly to enable the ore body to generate fatigue, further enable the ore body to generate a complex fracture network and finally realize the damage of the ore body;

transient and static fracturing based on carbon dioxide

Step 1: adjusting the seventeenth valve, the eighth valve, the ninth valve, the first valve, the fourth valve, the fifth valve and the third valve to be in an opening state, maintaining the rest valves in a closing state, simultaneously opening a carbon dioxide storage tank, performing primary pressurization on carbon dioxide by a first booster pump, performing secondary pressurization by a second booster pump, directly feeding the carbon dioxide subjected to secondary pressurization into an energy accumulator, releasing high-pressure carbon dioxide by the energy accumulator after the pressure in the energy accumulator reaches a set value, sequentially feeding the high-pressure carbon dioxide into an annular sealing section of a drill hole through an inner cavity of a fracturing chamber and a fracturing hole, and fracturing an ore body through transient high pressure;

step 2: closing the fourth valve and the fifth valve, opening the second valve, simultaneously maintaining the opening states of the seventeenth valve V, the eighth valve, the ninth valve, the first valve and the third valve, completing the direct injection of the carbon dioxide subjected to the two-stage pressurization into the annular sealing and separating section of the inner cavity of the fracturing chamber and the drill hole, and further fracturing the ore body through static high pressure to expand the fracture;

step 3; repeating the step 1 and the step 2, and performing transient and static fracturing processes repeatedly to enable the ore body to generate fatigue, further enable the ore body to generate a complex fracture network and finally realize the damage of the ore body;

transient and static fracturing based on supercritical carbon dioxide

Step 1: adjusting a fifteenth valve, a sixteenth valve, an eighth valve, a ninth valve, a first valve, a fourth valve, a fifth valve and a third valve to an open state, maintaining the rest valves in a closed state, simultaneously opening a carbon dioxide storage tank, feeding carbon dioxide into a heater, heating the carbon dioxide in the heater to above 31.1 ℃, discharging the heated carbon dioxide from the heater, performing primary pressurization through the first booster pump, performing secondary pressurization through the second booster pump until the pressure reaches above 7.4MPa, further forming supercritical carbon dioxide, directly feeding the supercritical carbon dioxide into an energy accumulator for storage, releasing high-pressure supercritical carbon dioxide from the energy accumulator after the pressure in the energy accumulator reaches a set value, feeding the high-pressure supercritical carbon dioxide into the annular isolation section of the drill hole through a fracturing chamber and a fracturing hole in sequence, fracturing the ore body by transient high pressure;

step 2: closing the fourth valve and the fifth valve, opening the second valve, simultaneously maintaining the opening states of the fifteenth valve, the sixteenth valve, the eighth valve, the ninth valve, the first valve and the third valve, directly injecting formed supercritical carbon dioxide into the inner cavity of the fracturing chamber and the annular sealing section of the drill hole, and further fracturing an ore body through static high pressure to expand the fracture;

step 3; repeating the step 1 and the step 2, and performing transient and static fracturing processes repeatedly to enable the ore body to generate fatigue, further enable the ore body to generate a complex fracture network and finally realize the damage of the ore body;

step six: maintaining the opening state of the third valve, closing all other opened valves, closing the gas pressurization system, then opening the sixth valve, recovering the waste gas through the waste gas storage tank and realizing pressure relief, and finally closing the third valve and the sixth valve;

step seven: the sixth valve, the twelfth valve, the twentieth valve and the twenty-first valve are adjusted to be in an opening state, the pressure inside the high-pressure closed nozzle is instantly reduced, the thrust spring is recovered to an extension state from a compression state, the nozzle sealing plate is recovered to the opening state from the closing state at the moment, the annular packing air bag is gradually retracted and exhausted, discharged gas is recovered through the waste gas storage tank, and after the annular packing air bag is retracted to the initial volume, the deblocking is finished.

The invention has the beneficial effects that:

1. the rock breaking effect is good. The method adopts a mode of combining a transient gas fracturing technology and a static gas fracturing technology to fracture the ore body, the transient gas fracturing technology acts on the ore body and generates large cracks under the action of larger pressure, the static gas fracturing technology acts on the ore body and communicates and expands the cracks by continuously and stably injecting high-pressure gas, and the ore body can generate fatigue action through the repeated action on the ore body for multiple times of transient and static fracturing, so that the ore body is damaged.

2. The safety is good. The invention combines the transient gas fracturing technology and the static gas fracturing technology to be applied to strip mine exploitation, compared with the traditional explosive blasting technology and the traditional high-energy gas fracturing technology, the whole process does not generate sparks and explosives, thereby avoiding secondary damage caused by explosive explosion and improving safety.

3. The pressure is controllable. The transient high-pressure gas can play a role in dynamic impact, and the effect of dynamic load rock breaking can be dynamically regulated and controlled by controlling parameters such as pressure, gas volume and the like in the rock breaking process; the static gas fracturing technology can dynamically adjust the rock breaking effect by controlling the gas flow and the gas pressure, and can effectively reduce the foam coal amount in open-pit coal mining, thereby improving the grade of mineral resources; the rock breaking lumpiness can be controlled in the open-pit metal mine exploitation, and the generation of large block rate can be controlled.

4. High efficiency and rapidness. The gas pressurization system provided by the invention has the advantages that the injection flow and the gas diffusion degree of high-pressure gas are improved on the premise of ensuring the pressure, the action range is effectively expanded, meanwhile, the fracturing of ore bodies is carried out by utilizing various and multiphase gases, the fracture initiation pressure can be reduced, the rock breaking effect is improved, and the complex procedure of hole sealing is avoided by adopting a packer for sealing.

5. Environmental protection and low cost. The invention adopts the gas fracturing technology to replace the traditional explosive blasting technology, has the advantage of environmental protection, has sufficient resources such as nitrogen, carbon dioxide and the like, can be repeatedly utilized, and effectively reduces the cost.

In conclusion, the rock breaking device and method for strip mine under the combined action of transient static gas fracturing have the advantages of good rock breaking effect, good safety, controllable pressure, high efficiency, rapidness, environmental friendliness and low cost, and are suitable for ore body fracturing in strip mine mining.

Drawings

Fig. 1 is a schematic structural diagram of a rock breaking device for strip mines under the combined action of transient static gas fracturing (two sets of gas pressurization systems are connected in parallel in the figure, but multiple sets of gas pressurization systems can be connected in parallel according to rock breaking requirements);

FIG. 2 is an enlarged view of section I of FIG. 1;

in the figure, 1-a gas pressurization system, 2-an accumulator, 3-a cracking chamber, 4-a packer, 5-a gas injection pipe, 6-a drill hole, 7-a cracking hole, 8-a top plug, 9-a bottom plug, 10-a first pressure sensor, 11-a first flow sensor, 12-a second pressure sensor, 13-a second flow sensor, 14-an exhaust gas storage tank, 15-a third pressure sensor, 16-an air compressor, 17-an air storage tank, 18-a nitrogen generator, 19-a nitrogen storage tank, 20-a liquid nitrogen storage tank, 21-a carbon dioxide storage tank, 22-a heater, 23-a fourth pressure sensor, 24-a first booster pump, 25-a fifth pressure sensor, 26-a third flow sensor, 27-a second booster pump, 28-a sixth pressure sensor, 29-a fourth flow sensor, 30-a pressure reducing valve, 31-a toroidal bearing base, 32-a gas injection central column, 33-a toroidal isolation airbag, 34-high pressure closed nozzle, 35-thrust spring, 36-spout sealing plate, 37-seventh pressure sensor, 38-sensor signal adapter, V1-first valve, V2-second valve, V3-third valve, V4-fourth valve, V5-fifth valve, V6-sixth valve, V7-seventh valve, V8-eighth valve, V9-ninth valve, V10-tenth valve, V11-eleventh valve, V12-twelfth valve, V13-thirteenth valve, V13-fourteenth valve, V13-fifteenth valve, V13-sixteenth valve, V13-seventeenth valve, V13-eighteenth valve, V13-nineteenth valve, V13-twenty-third valve, V13-twenty-first valve, V13-twelfth valve, T13-third valve, T13-sixth three-third valve, T13-seventh three-third valve, V13-fifth three-third valve, V13, T13-third three-third valve, V13, T13, t8-eighth tee, T9-ninth tee, T10-tenth tee, ST 1-first cross, ST 2-second cross.

Detailed Description

The invention is described in further detail below with reference to the figures and the specific embodiments.

As shown in fig. 1 and 2, a rock breaking device for strip mine under the combined action of transient static gas fracturing comprises a gas pressurization system 1, an energy accumulator 2, a fracturing chamber 3, a packer 4 and a gas injection pipe 5; the number of the gas pressurization systems 1 is a plurality, and the gas pressurization systems 1 are arranged in parallel; the gas pressurization system 1 and the energy storage device 2 are positioned outside the borehole 6; the fracturing chamber 3 is positioned inside the borehole 6; a cracking hole 7 is formed in the side wall of the cracking chamber 3, and the inner cavity of the cracking chamber 3 is communicated with the drill hole 6 through the cracking hole 7; the packer 4 is arranged in an annular space between the fracturing chamber 3 at the upper side and the lower side of the fracturing hole 7 and the inner hole wall of the drill hole 6; the gas pressurization system 1 is output in two paths, the first path is communicated with the inner cavity of the fracturing chamber 3 through a gas injection pipe 5, and the second path is communicated with the packer 4 through the gas injection pipe 5; and a gas injection pipe 5 for communicating the gas pressurization system 1 and the fracturing chamber 3 is arranged in parallel with the energy accumulator 2.

The cracking chamber 3 can adopt a single-stage structure or a multi-stage series structure; when the cracking chamber 3 adopts a single-stage structure, the upper and lower end openings of the cracking chamber 3 are respectively plugged by a top plug 8 and a bottom plug 9; when the cracking chambers 3 adopt a multistage series structure, the upper end cylinder openings of the first-stage cracking chambers 3 are plugged through the top plugs 8, the adjacent cracking chambers 3 are connected in series in a screwing mode, and the lower end cylinder openings of the first-stage cracking chambers 3 are plugged through the bottom plugs 9.

The gas pressurization system 1 arranged in parallel is intersected with a first tee joint T1, and a first pressure sensor 10, a first flow sensor 11, a first valve V1, a second tee joint T2, a second valve V2, a third tee joint T3, a first tee joint ST1 and a third valve V3 are sequentially arranged on a gas injection pipe 5 between the first tee joint T1 and the cracking chamber 3; the air inlet end of the energy storage device 2 is communicated with a second tee joint T2, and a fourth valve V4 is arranged on a pipeline between the air inlet end of the energy storage device 2 and the second tee joint T2; the air outlet end of the energy accumulator 2 is communicated with a third tee joint T3, and a second pressure sensor 12, a second flow sensor 13 and a fifth valve V5 are sequentially arranged on a pipeline between the air outlet end of the energy accumulator 2 and the third tee joint T3; an exhaust gas storage tank 14 is arranged outside the drill 6, an air inlet end of the exhaust gas storage tank 14 is communicated with the first four-way joint ST1, and a third pressure sensor 15 and a sixth valve V6 are sequentially arranged on a pipeline between the air inlet end of the exhaust gas storage tank 14 and the first four-way joint ST 1.

The gas pressurization system 1 comprises an air compressor 16, an air storage tank 17, a nitrogen making machine 18, a nitrogen storage tank 19, a liquid nitrogen storage tank 20, a carbon dioxide storage tank 21 and a heater 22; the air outlet end of the air compressor 16 is communicated with a first tee joint T1, and a fourth pressure sensor 23, a fourth tee joint T4, a seventh valve V7, a second tee joint ST2, a first booster pump 24, a fifth pressure sensor 25, a third flow sensor 26, an eighth valve V8, a second booster pump 27, a sixth pressure sensor 28, a fourth flow sensor 29 and a ninth valve V9 are sequentially arranged on a pipeline between the air outlet end of the air compressor 16 and the first tee joint T1; the air inlet end of the air storage tank 17 is communicated with a fourth tee T4, and a tenth valve V10 is arranged on a pipeline between the air inlet end of the air storage tank 17 and the fourth tee T4; the air outlet end of the air storage tank 17 is communicated with the air inlet end of the nitrogen making machine 18, and an eleventh valve V11 is arranged on a pipeline between the air outlet end of the air storage tank 17 and the air inlet end of the nitrogen making machine 18; the outlet end of the nitrogen generator 18 is communicated with the inlet end of the nitrogen storage tank 19, and a twelfth valve V12 is arranged on a pipeline between the outlet end of the nitrogen generator 18 and the inlet end of the nitrogen storage tank 19; the gas outlet end of the nitrogen storage tank 19 is communicated with a second four-way joint ST2, and a thirteenth valve V13 and a fifth three-way joint T5 are sequentially arranged on a pipeline between the gas outlet end of the nitrogen storage tank 19 and the second four-way joint ST 2; the liquid outlet end of the liquid nitrogen storage tank 20 is communicated with a fifth tee T5, and a fourteenth valve V14 is arranged on a pipeline between the liquid outlet end of the liquid nitrogen storage tank 20 and the fifth tee T5; the outlet end of the carbon dioxide storage tank 21 is communicated with the feed end of the heater 22, and a sixth tee T6 and a fifteenth valve V15 are sequentially arranged on a pipeline between the outlet end of the carbon dioxide storage tank 21 and the feed end of the heater 22; the discharge end of the heater 22 is communicated with the second four-way joint ST2, and a sixteenth valve V16 and a seventh three-way joint T7 are sequentially arranged on a pipeline between the discharge end of the heater 22 and the second four-way joint ST 2; the sixth tee T6 and the seventh tee T7 are communicated through a straight pipeline, and a seventeenth valve V17 is arranged on the straight pipeline.

In one set of the gas pressurization system 1, an eighth tee joint T8 is further arranged on a pipeline between the third flow sensor 26 and the eighth valve V8, and an eighteenth valve V18, a pressure reducing valve 30, a nineteenth valve V19, a ninth tee joint T9 and a thirteenth tee joint T10 are sequentially arranged on the gas injection pipe 5 between the eighth tee joint T8 and the packer 4; the thirteenth way T10 is divided into two ways to be communicated with the packer 4, a twentieth valve V20 is arranged on the first way pipeline of the tenth way T10 and the packer 4, and a twenty-first valve V21 is arranged on the second way pipeline of the tenth way T10 and the packer 4; the thirteenth port T10 communicates with the first four-way port ST1, and a twenty-second valve V22 is provided in a line between the thirteenth port T10 and the first four-way port ST 1.

The packer 4 comprises an annular bearing base 31, a gas injection central pipe column 32, an annular packing air bag 33 and a high-pressure closed nozzle 34; the annular bearing base 31 is fixedly sleeved outside the fracturing chamber 3, the gas injection central pipe column 32 is fixedly inserted in the annular bearing base 31, and the gas injection central pipe column 32 is communicated with the gas injection pipe 5; the annular packing air bag 33 is sleeved on the circumferential outer side of the annular bearing base 31, and the annular packing air bag 33 is communicated with the gas injection pipe 5 through a high-pressure closed spray head 34; a thrust spring 35 is coaxially arranged on the inner side of the central orifice of the high-pressure closed nozzle 34, one end of the thrust spring 35 is connected with the high-pressure closed nozzle 34, and the other end of the thrust spring 35 is connected with a nozzle sealing plate 36.

A seventh pressure sensor 37 is arranged on the cylinder wall of the fracturing chamber 3 between the packers 4 at the upper side and the lower side of the fracturing hole 7, and a sensor signal adapter 38 is arranged at the upper part of the cylinder wall of the fracturing chamber 3; the drilling 6 is externally provided with an information collector and a computer, the signal output ends of the first pressure sensor 10, the second pressure sensor 12, the third pressure sensor 15, the fourth pressure sensor 23, the fifth pressure sensor 25, the sixth pressure sensor 28, the seventh pressure sensor 37, the first flow sensor 11, the second flow sensor 13, the third flow sensor 26 and the fourth flow sensor 29 are electrically connected with the information collector, the signal output end of the seventh pressure sensor 37 is electrically connected with the information collector through a sensor signal adapter 38, and the signal output end of the information collector is electrically connected with the computer.

A rock breaking method for the combined action of transient static gas fracturing for strip mines adopts a rock breaking device for the combined action of transient static gas fracturing for strip mines, and comprises the following steps:

the method comprises the following steps: determining the hole distribution position and the hole distribution quantity of the drill holes 6 according to the mining requirement of the strip mine;

step two: processing the drill holes 6 at the determined hole distribution positions by using drilling equipment until the drill holes 6 reach a preset depth;

step three: sending the fracturing chamber 3 equipped with the packer 4 into the borehole 6;

step four: the seventh valve V7, the eighth valve V8, the ninth valve V9, the eighteenth valve V18, the nineteenth valve V19, the twentieth valve V20 and the twenty-first valve V21 are adjusted to be in an opening state, the other valves are maintained in a closing state, the air compressor 16 is started at the same time, compressed air is firstly pressurized by the first booster pump 24, then flows through the pressure reducing valve 30 and enters the gas injection center pipe column 32, the compressed air after being regulated by the pressure reducing valve 30 flows out of the gas injection center pipe column 32 and directly enters the annular isolation air bag 33, the nozzle sealing plate 36 is in an opening state at the moment, the compressed air can smoothly pass through the high-pressure closed nozzle 34 to gradually inflate and expand the annular isolation air bag 33 until the expanded annular isolation air bag 33 is attached to the inner hole wall of the drill hole 6, the pressure in the high-pressure closed nozzle 34 gradually rises along with the continuous injection of the compressed air, and when the pressure exceeds the spring force of the thrust spring 35, at the moment, the spout sealing plate 36 is closed under the pressure, so that the high-pressure closed nozzle 34 is closed, the annular packing air bag 33 is inflated, the annular space of the drill holes 6 on the upper side and the lower side of the fractured hole 7 is packed, an annular packing section is formed, all opened valves are quickly closed, and the air compressor 16 and the first booster pump 24 are closed;

step five: starting the gas pressurization system 1, and according to the difference of fracturing gas, dividing into the following five operation modes:

transient and static fracturing based on air

Step 1: the seventh valve V7, the eighth valve V8, the ninth valve V9, the first valve V1, the fourth valve V4, the fifth valve V5 and the third valve V3 are adjusted to be in an opening state, the rest valves are maintained in a closing state, the air compressor 16 is started at the same time, compressed air is firstly subjected to primary pressurization through the first booster pump 24, then secondary pressurization is carried out through the second booster pump 27, the compressed air after the secondary pressurization directly enters the energy storage device 2, when the pressure in the energy storage device 2 reaches a set value, the energy storage device 2 releases high-pressure air, the high-pressure air sequentially passes through the inner cavity of the fracturing chamber 3 and the fracturing hole 7 to enter the annular partition section of the drill hole 6, and the ore body is fractured through transient high pressure;

step 2: closing the fourth valve V4 and the fifth valve V5, opening the second valve V2, simultaneously maintaining the opening states of the seventh valve V7, the eighth valve V8, the ninth valve V9, the first valve V1 and the third valve V3, completing the direct injection of compressed air after two-stage pressurization into the annular sealing sections of the inner cavity of the fracturing chamber 3 and the drill hole 6, and further fracturing the ore body through static high pressure to expand the fractures;

step 3; repeating the step 1 and the step 2, and performing transient and static fracturing processes repeatedly to enable the ore body to generate fatigue, further enable the ore body to generate a complex fracture network and finally realize the damage of the ore body;

② static fracturing based on liquid nitrogen

The fourteenth valve V14, the eighth valve V8, the ninth valve V9, the first valve V1, the second valve V2 and the third valve V3 are adjusted to be in an opening state, the other valves are maintained in a closing state, the liquid nitrogen storage tank 20 is opened, the output liquid nitrogen is subjected to primary pressurization through the first booster pump 24, then secondary pressurization is carried out through the second booster pump 27, the pressurized liquid nitrogen is directly injected into the annular sealing section of the inner cavity of the cracking chamber 3 and the drill hole 6, the liquid nitrogen is gasified to absorb a large amount of heat and form low-temperature gas, so that cold impact effect is generated on the ore body, the brittleness of the ore body is increased, high-pressure gas formed after the liquid nitrogen is gasified and expanded can also act on the ore body along with continuous injection of the liquid nitrogen, the ore body can generate a complex fracture network under the repeated action of cold impact and high pressure, and finally the damage of the ore body is realized;

transient and static fracturing based on nitrogen

Step 1: a tenth valve V10, an eleventh valve V11, a twelfth valve V12, a thirteenth valve V13, an eighth valve V8, a ninth valve V9, a first valve V1, a fourth valve V4, a fifth valve V5 and a third valve V3 are adjusted to be in an open state, the other valves are maintained in a closed state, an air compressor 16 is started simultaneously, compressed air firstly enters an air storage tank 17, then flows into a nitrogen making machine 18 from the air storage tank 17, then is output by the nitrogen making machine 18 and injected into a nitrogen storage tank 19, then nitrogen output by the nitrogen storage tank 19 is subjected to primary pressurization through a first booster pump 24 and then is subjected to secondary pressurization through a second booster pump 27, the nitrogen after the secondary pressurization directly enters an energy storage device 2, after the pressure in the energy storage device 2 reaches a set value, high-pressure nitrogen is released by the energy storage device 2, and sequentially enters a circumferential isolation section of a drill hole 6 through an inner cavity of a fracturing chamber 3 and a fracturing hole 7, fracturing the ore body by transient high pressure;

step 2: closing the fourth valve V4 and the fifth valve V5, opening the second valve V2, simultaneously maintaining the opening states of the tenth valve V10, the eleventh valve V11, the twelfth valve V12, the thirteenth valve V13, the eighth valve V8, the ninth valve V9, the first valve V1 and the third valve V3, directly injecting the nitrogen subjected to secondary pressurization into the annular sealing section of the inner cavity of the fracturing chamber 3 and the drill hole 6, and further fracturing the ore body through static high pressure to expand the fractures;

step 3; repeating the step 1 and the step 2, and performing transient and static fracturing processes repeatedly to enable the ore body to generate fatigue, further enable the ore body to generate a complex fracture network and finally realize the damage of the ore body;

transient and static fracturing based on carbon dioxide

Step 1: the seventeenth valve V17, the eighth valve V8, the ninth valve V9, the first valve V1, the fourth valve V4, the fifth valve V5 and the third valve V3 are adjusted to be in an opening state, the rest valves are maintained in a closing state, meanwhile, the carbon dioxide storage tank 21 is opened, the carbon dioxide is firstly subjected to primary pressurization through the first booster pump 24, then secondary pressurization is carried out through the second booster pump 27, the carbon dioxide after the secondary pressurization directly enters the energy storage device 2, when the pressure in the energy storage device 2 reaches a set value, the energy storage device 2 releases high-pressure carbon dioxide, the high-pressure carbon dioxide sequentially passes through the inner cavity of the fracturing chamber 3 and the fracturing hole 7 to enter the annular sealing section of the drill hole 6, and the ore body is fractured through transient high pressure;

step 2: closing the fourth valve V4 and the fifth valve V5, opening the second valve V2, simultaneously maintaining the opening states of the seventeenth valve V17, the eighth valve V8, the ninth valve V9, the first valve V1 and the third valve V3, directly injecting carbon dioxide subjected to two-stage pressurization into the annular sealing section of the inner cavity of the fracturing chamber 3 and the drill hole 6, and further fracturing the ore body through static high pressure to expand the fractures;

step 3; repeating the step 1 and the step 2, and performing transient and static fracturing processes repeatedly to enable the ore body to generate fatigue, further enable the ore body to generate a complex fracture network and finally realize the damage of the ore body;

transient and static fracturing based on supercritical carbon dioxide

Step 1: a fifteenth valve V15, a sixteenth valve V16, an eighth valve V8, a ninth valve V9, a first valve V1, a fourth valve V4, a fifth valve V5 and a third valve V3 are adjusted to be in an opening state, the rest valves are kept in a closing state, a carbon dioxide storage tank 21 is opened at the same time, carbon dioxide firstly enters a heater 22 and is heated to above 31.1 ℃ in the heater 22, after the heated carbon dioxide flows out of the heater 22, the carbon dioxide is firstly subjected to primary pressurization by a first booster pump 24 and then subjected to secondary pressurization by a second booster pump 27 until the pressure reaches above 7.4MPa, so that supercritical carbon dioxide is formed and directly enters an energy storage device 2 for storage, when the pressure in the energy storage device 2 reaches a set value, the energy storage device 2 releases the high-pressure supercritical carbon dioxide, the high-pressure supercritical carbon dioxide sequentially enters a circumferential sealing section of a drill hole 6 through an inner cavity of a cracking chamber 3 and a cracking hole 7, fracturing the ore body by transient high pressure;

step 2: closing the fourth valve V4 and the fifth valve V5, opening the second valve V2, simultaneously maintaining the opening states of the fifteenth valve V15, the sixteenth valve V16, the eighth valve V8, the ninth valve V9, the first valve V1 and the third valve V3, directly injecting formed supercritical carbon dioxide into the annular sealing section of the inner cavity of the fracturing chamber 3 and the drill hole 6, and further fracturing an ore body through static high pressure to expand cracks;

step 3; repeating the step 1 and the step 2, and performing transient and static fracturing processes repeatedly to enable the ore body to generate fatigue, further enable the ore body to generate a complex fracture network and finally realize the damage of the ore body;

step six: maintaining the opening state of the third valve V3, closing all other opened valves, closing the gas pressurization system 1, then opening the sixth valve V6, recovering the waste gas through the waste gas storage tank 14 and realizing pressure relief, and finally closing the third valve V3 and the sixth valve V6;

step seven: the sixth valve V6, the twentieth valve V22, the twentieth valve V20 and the twenty-first valve V21 are adjusted to be in an open state, the pressure in the high-pressure closed nozzle 34 is instantaneously reduced, the thrust spring 35 is restored from a compressed state to an extended state, the spout sealing plate 36 is restored from the closed state to the open state, the annular isolation air bag 33 is gradually retracted and exhausted, the exhausted gas is recovered through the waste gas storage tank 14, and when the annular isolation air bag 33 is retracted to the initial volume, the unsealing is finished.

The embodiments are not intended to limit the scope of the present invention, and all equivalent implementations or modifications without departing from the scope of the present invention are intended to be included in the scope of the present invention.

Claims (8)

1. The utility model provides a rock breaking device of static gas fracturing combined action of transient state for strip mine which characterized in that: comprises a gas pressurization system, an energy accumulator, a cracking chamber, a packer and a gas injection pipe; the number of the gas pressurization systems is a plurality, and the gas pressurization systems are arranged in parallel; the gas pressurization system and the energy storage device are positioned outside the drill hole; the fracturing chamber is positioned inside the drill hole; a cracking hole is formed in the side wall of the cracking chamber, and the inner cavity of the cracking chamber is communicated with the drill hole through the cracking hole; the packer is arranged in an annular space between the fracturing chambers on the upper side and the lower side of the fracturing hole and the inner hole wall of the drill hole; the gas pressurization system is output in two paths, the first path is communicated with the inner cavity of the fracturing chamber through a gas injection pipe, and the second path is communicated with the packer through the gas injection pipe; and the gas injection pipe for communicating the gas pressurization system with the cracking chamber is connected with the energy accumulator in parallel.

2. The transient static gas fracturing coactive rock breaking device for open pit mines of claim 1, wherein: the cracking chamber can adopt a single-stage structure or a multi-stage series structure; when the fracturing chamber adopts a single-stage structure, the upper and lower end openings of the fracturing chamber are respectively plugged by a top plug and a bottom plug; when the cracking chambers adopt a multistage series structure, the upper end barrel openings of the first-stage cracking chambers are plugged through the top plugs, the adjacent cracking chambers are connected in series in a screwing mode, and the lower end barrel openings of the first-stage cracking chambers are plugged through the bottom plugs.

3. The transient static gas fracturing coactive rock breaking device for open pit mines of claim 1, wherein: the gas pressurization systems arranged in parallel are intersected with a first tee joint, and a first pressure sensor, a first flow sensor, a first valve, a second tee joint, a second valve, a third tee joint, a first four-way joint and a third valve are sequentially arranged on a gas injection pipe between the first tee joint and the fracturing chamber; the air inlet end of the energy accumulator is communicated with the second tee joint, and a fourth valve is arranged on a pipeline between the air inlet end of the energy accumulator and the second tee joint; the gas outlet end of the energy accumulator is communicated with the third tee joint, and a second pressure sensor, a second flow sensor and a fifth valve are sequentially arranged on a pipeline between the gas outlet end of the energy accumulator and the third tee joint; and a waste gas storage tank is arranged outside the drill hole, the air inlet end of the waste gas storage tank is communicated with the first four-way joint, and a third pressure sensor and a sixth valve are sequentially arranged on a pipeline between the air inlet end of the waste gas storage tank and the first four-way joint.

4. The transient static gas fracturing coactive rock breaking device for open pit mines of claim 3, wherein: the gas pressurization system comprises an air compressor, an air storage tank, a nitrogen making machine, a nitrogen storage tank, a liquid nitrogen storage tank, a carbon dioxide storage tank and a heater; the air outlet end of the air compressor is communicated with the first tee joint, and a fourth pressure sensor, a fourth tee joint, a seventh valve, a second tee joint, a first booster pump, a fifth pressure sensor, a third flow sensor, an eighth valve, a second booster pump, a sixth pressure sensor, a fourth flow sensor and a ninth valve are sequentially arranged on a pipeline between the air outlet end of the air compressor and the first tee joint; the air inlet end of the air storage tank is communicated with the fourth tee joint, and a tenth valve is arranged on a pipeline between the air inlet end of the air storage tank and the fourth tee joint; an air outlet end of the air storage tank is communicated with an air inlet end of the nitrogen making machine, and an eleventh valve is arranged on a pipeline between the air outlet end of the air storage tank and the air inlet end of the nitrogen making machine; the gas outlet end of the nitrogen making machine is communicated with the gas inlet end of the nitrogen storage tank, and a twelfth valve is arranged on a pipeline between the gas outlet end of the nitrogen making machine and the gas inlet end of the nitrogen storage tank; the gas outlet end of the nitrogen storage tank is communicated with the second four-way joint, and a thirteenth valve and a fifth three-way joint are sequentially arranged on a pipeline between the gas outlet end of the nitrogen storage tank and the second four-way joint; the liquid outlet end of the liquid nitrogen storage tank is communicated with the fifth tee joint, and a fourteenth valve is arranged on a pipeline between the liquid outlet end of the liquid nitrogen storage tank and the fifth tee joint; the gas outlet end of the carbon dioxide storage tank is communicated with the feed end of the heater, and a sixth tee joint and a fifteenth valve are sequentially arranged on a pipeline between the gas outlet end of the carbon dioxide storage tank and the feed end of the heater; the discharge end of the heater is communicated with the second four-way joint, and a sixteenth valve and a seventh three-way joint are sequentially arranged on a pipeline between the discharge end of the heater and the second four-way joint; the sixth tee joint and the seventh tee joint are communicated through a straight pipeline, and a seventeenth valve is arranged on the straight pipeline.

5. The transient static gas fracturing coactive rock breaking device for open pit mines according to claim 4, wherein: in one set of the gas pressurization system, an eighth tee joint is further arranged on a pipeline between the third flow sensor and the eighth valve, and an eighteenth valve, a pressure reducing valve, a nineteenth valve, a ninth tee joint and a tenth tee joint are sequentially arranged on a gas injection pipe between the eighth tee joint and the packer; the thirteenth pipeline is divided into two paths and communicated with the packer, a twentieth valve is arranged on the first path of pipeline of the tenth pipeline and the packer, and a twenty-first valve is arranged on the second path of pipeline of the tenth pipeline and the packer; the tenth tee is communicated with the first four-way, and a twelfth valve is arranged on a pipeline between the tenth tee and the first four-way.

6. The transient static gas fracturing coactive rock breaking device for open pit mines of claim 1, wherein: the packer comprises an annular bearing base, a gas injection central pipe column, an annular packing air bag and a high-pressure closed spray head; the annular bearing base is fixedly sleeved outside the fracturing chamber, the gas injection central pipe column is fixedly inserted in the annular bearing base, and the gas injection central pipe column is communicated with the gas injection pipe; the annular packing air bag is sleeved on the circumferential outer side of the annular bearing base, and the annular packing air bag is communicated with the gas injection pipe through a high-pressure closed nozzle; and a thrust spring is coaxially arranged on the inner side of the central orifice of the high-pressure closed nozzle, one end of the thrust spring is connected with the high-pressure closed nozzle, and the other end of the thrust spring is connected with a nozzle sealing plate.

7. The transient static gas fracturing coactive rock breaking device for open pit mines according to claim 4, wherein: a seventh pressure sensor is arranged on the wall of the fracturing chamber between the packers at the upper side and the lower side of the fracturing hole, and a sensor signal adapter is arranged at the upper part of the wall of the fracturing chamber; the drilling outside is provided with information collection station and computer, first pressure sensor, second pressure sensor, third pressure sensor, fourth pressure sensor, fifth pressure sensor, sixth pressure sensor, seventh pressure sensor, first flow sensor, second flow sensor, third flow sensor and fourth flow sensor's signal output part all carries out the electricity with information collection station and is connected, seventh pressure sensor's signal output part carries out the electricity through sensor signal adapter and information collection station and is connected, and information collection station's signal output part carries out the electricity with the computer and is connected.

8. A rock breaking method for an open pit mine under the combined action of transient static gas fracturing, which adopts the rock breaking device for the combined action of the transient static gas fracturing of the open pit mine according to claim 1, and is characterized by comprising the following steps:

the method comprises the following steps: determining the hole distribution position and the hole distribution quantity of the drill holes according to the mining requirement of the strip mine;

step two: drilling holes at the determined hole distribution positions by using drilling equipment until the drilling holes reach a preset depth;

step three: sending the fracturing chamber with the packer into a drill hole;

step four: the seventh valve, the eighth valve, the ninth valve, the eighteenth valve, the nineteenth valve, the twentieth valve and the twenty-first valve are adjusted to be in an opening state, the rest valves are maintained in a closing state, the air compressor is started simultaneously, compressed air is firstly pressurized by the first booster pump, then flows through the pressure reducing valve and enters the air injection central pipe column, the compressed air after being regulated by the pressure reducing valve flows out of the air injection central pipe column and directly enters the annular packing air bag, the nozzle sealing plate is in an opening state at the moment, the compressed air can smoothly pass through the high-pressure closed nozzle to enable the annular packing air bag to be gradually inflated and expanded until the expanded annular packing air bag is tightly attached to the inner hole wall of the drill hole, the pressure in the high-pressure closed nozzle is gradually increased along with the continuous injection of the compressed air, and when the pressure exceeds the spring force of the thrust spring, the nozzle sealing plate is, then the high-pressure closed spray head is closed, the annular packing air bag is inflated, the annular space of the drill holes on the upper side and the lower side of the fractured hole is packed, an annular packing section is formed, all opened valves are quickly closed, and the air compressor and the first booster pump are closed simultaneously;

step five: starting a gas pressurization system, and dividing the gas pressurization system into the following five operation modes according to different fracturing gases:

transient and static fracturing based on air

Step 1: the seventh valve, the eighth valve, the ninth valve, the first valve, the fourth valve, the fifth valve and the third valve are adjusted to be in an opening state, the rest valves are maintained in a closing state, an air compressor is started simultaneously, compressed air is firstly subjected to primary pressurization through the first booster pump, then secondary pressurization is carried out through the second booster pump, the compressed air after the secondary pressurization is finished directly enters the energy accumulator, after the pressure in the energy accumulator reaches a set value, high-pressure air is released by the energy accumulator, the high-pressure air sequentially passes through the fracturing chamber inner cavity and the fracturing hole to enter the annular sealing section of the drill hole, and the ore body is fractured through transient high pressure;

step 2: closing the fourth valve and the fifth valve, opening the second valve, simultaneously maintaining the opening states of the seventh valve, the eighth valve, the ninth valve, the first valve and the third valve, directly injecting compressed air subjected to two-stage pressurization into the inner cavity of the fracturing chamber and the annular sealing section of the drill hole, and further fracturing an ore body through static high pressure to expand the fracture;

step 3; repeating the step 1 and the step 2, and performing transient and static fracturing processes repeatedly to enable the ore body to generate fatigue, further enable the ore body to generate a complex fracture network and finally realize the damage of the ore body;

② static fracturing based on liquid nitrogen

The fourteenth valve, the eighth valve, the ninth valve, the first valve, the second valve and the third valve are adjusted to be in an opening state, the rest valves are maintained in a closing state, a liquid nitrogen storage tank is opened, output liquid nitrogen is firstly subjected to primary pressurization through the first booster pump and then subjected to secondary pressurization through the second booster pump, the pressurized liquid nitrogen is directly injected into an inner cavity of the fracturing chamber and a circumferential sealing section of a drill hole, the liquid nitrogen is gasified to absorb a large amount of heat and form low-temperature gas, so that a cold impact effect is generated on an ore body, the brittleness of the ore body is increased, along with continuous injection of the liquid nitrogen, high-pressure gas formed after gasification and expansion of the liquid nitrogen also acts on the ore body, and the ore body can generate a complex fracture network under repeated actions of cold impact and high pressure, and finally the damage of the ore body is realized;

transient and static fracturing based on nitrogen

Step 1: the tenth valve, the eleventh valve, the twelfth valve, the thirteenth valve, the eighth valve, the ninth valve, the first valve, the fourth valve, the fifth valve and the third valve are adjusted to be in an opening state, the other valves are maintained in a closing state, simultaneously starting the air compressor, leading the compressed air to enter the air storage tank firstly, then leading the compressed air to flow into the nitrogen making machine from the air storage tank, then leading the nitrogen making machine to output nitrogen and injecting the nitrogen into the nitrogen storage tank, then nitrogen output by the nitrogen storage tank is subjected to primary pressurization through a first booster pump, then secondary pressurization is carried out through a second booster pump, the nitrogen after the secondary pressurization directly enters an energy accumulator, when the pressure in the energy accumulator reaches a set value, releasing high-pressure nitrogen by the energy accumulator, sequentially passing the high-pressure nitrogen through the inner cavity of the fracturing chamber and the fracturing hole to enter the annular sealing section of the drilled hole, and fracturing an ore body by transient high pressure;

step 2: closing the fourth valve and the fifth valve, opening the second valve, simultaneously maintaining the opening states of the tenth valve, the eleventh valve, the twelfth valve, the thirteenth valve, the eighth valve, the ninth valve, the first valve and the third valve, directly injecting nitrogen after secondary pressurization into the inner cavity of the fracturing chamber and the annular sealing section of the drill hole, and further fracturing an ore body through static high pressure to expand the fracture;

step 3; repeating the step 1 and the step 2, and performing transient and static fracturing processes repeatedly to enable the ore body to generate fatigue, further enable the ore body to generate a complex fracture network and finally realize the damage of the ore body;

transient and static fracturing based on carbon dioxide

Step 1: adjusting the seventeenth valve, the eighth valve, the ninth valve, the first valve, the fourth valve, the fifth valve and the third valve to be in an opening state, maintaining the rest valves in a closing state, simultaneously opening a carbon dioxide storage tank, performing primary pressurization on carbon dioxide by a first booster pump, performing secondary pressurization by a second booster pump, directly feeding the carbon dioxide subjected to secondary pressurization into an energy accumulator, releasing high-pressure carbon dioxide by the energy accumulator after the pressure in the energy accumulator reaches a set value, sequentially feeding the high-pressure carbon dioxide into an annular sealing section of a drill hole through an inner cavity of a fracturing chamber and a fracturing hole, and fracturing an ore body through transient high pressure;

step 2: closing the fourth valve and the fifth valve, opening the second valve, simultaneously maintaining the opening states of the seventeenth valve V, the eighth valve, the ninth valve, the first valve and the third valve, completing the direct injection of the carbon dioxide subjected to the two-stage pressurization into the annular sealing and separating section of the inner cavity of the fracturing chamber and the drill hole, and further fracturing the ore body through static high pressure to expand the fracture;

step 3; repeating the step 1 and the step 2, and performing transient and static fracturing processes repeatedly to enable the ore body to generate fatigue, further enable the ore body to generate a complex fracture network and finally realize the damage of the ore body;

transient and static fracturing based on supercritical carbon dioxide

Step 1: adjusting a fifteenth valve, a sixteenth valve, an eighth valve, a ninth valve, a first valve, a fourth valve, a fifth valve and a third valve to an open state, maintaining the rest valves in a closed state, simultaneously opening a carbon dioxide storage tank, feeding carbon dioxide into a heater, heating the carbon dioxide in the heater to above 31.1 ℃, discharging the heated carbon dioxide from the heater, performing primary pressurization through the first booster pump, performing secondary pressurization through the second booster pump until the pressure reaches above 7.4MPa, further forming supercritical carbon dioxide, directly feeding the supercritical carbon dioxide into an energy accumulator for storage, releasing high-pressure supercritical carbon dioxide from the energy accumulator after the pressure in the energy accumulator reaches a set value, feeding the high-pressure supercritical carbon dioxide into the annular isolation section of the drill hole through a fracturing chamber and a fracturing hole in sequence, fracturing the ore body by transient high pressure;

step 2: closing the fourth valve and the fifth valve, opening the second valve, simultaneously maintaining the opening states of the fifteenth valve, the sixteenth valve, the eighth valve, the ninth valve, the first valve and the third valve, directly injecting formed supercritical carbon dioxide into the inner cavity of the fracturing chamber and the annular sealing section of the drill hole, and further fracturing an ore body through static high pressure to expand the fracture;

step 3; repeating the step 1 and the step 2, and performing transient and static fracturing processes repeatedly to enable the ore body to generate fatigue, further enable the ore body to generate a complex fracture network and finally realize the damage of the ore body;

step six: maintaining the opening state of the third valve, closing all other opened valves, closing the gas pressurization system, then opening the sixth valve, recovering the waste gas through the waste gas storage tank and realizing pressure relief, and finally closing the third valve and the sixth valve;

step seven: the sixth valve, the twelfth valve, the twentieth valve and the twenty-first valve are adjusted to be in an opening state, the pressure inside the high-pressure closed nozzle is instantly reduced, the thrust spring is recovered to an extension state from a compression state, the nozzle sealing plate is recovered to the opening state from the closing state at the moment, the annular packing air bag is gradually retracted and exhausted, discharged gas is recovered through the waste gas storage tank, and after the annular packing air bag is retracted to the initial volume, the deblocking is finished.

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