Leftover coal release device based on solid carbon dioxide

Abstract

The utility model relates to a leftover coal releasing device based on solid carbon dioxide, which belongs to the technical field of coal mining, and particularly comprises a solid carbon dioxide filling mixer truck and a plurality of solid carbon dioxide cracking carbon exhausters, exhaust ends of the plurality of solid carbon dioxide cracking carbon exhausters are connected with an adjacent goaf through a first connecting pipe, and the solid carbon dioxide cracking carbon exhausters are connected with an adjacent goaf through a second connecting pipe. The exhaust ends of the plurality of solid carbon dioxide cracking carbon exhausters are also connected with a solid carbon dioxide filling mixer truck through a second connecting pipe; the first connecting pipe and the second connecting pipe are respectively provided with a first carbon emission control valve and a second carbon emission control valve; according to the utility model, carbon dioxide in different states is fully utilized in a grading manner to release leftover coal, so that the safety degree of a leftover coal mining area is effectively improved.

Description

Technical Field

[0001] The utility model relates to a corner coal releasing device based on solid carbon dioxide, belonging to the technical field of coal mining. Background Art

[0002] Coal mines leave behind a large number of irregular and scattered corner coals when mining coal resources. Corner coals are prone to collapse under the action of mining stress and ground stress, forming a large amount of floating coal accumulation. Since the end of the working face does not fall completely after the return column, it leaves air leakage channels, which are prone to spontaneous combustion. It can be seen that the existence of a large amount of corner coals may cause power disasters, cause hidden dangers of spontaneous combustion, and lead to a large waste of coal resources.

[0003] At present, the mining of relatively large-sized marginal coal is mainly carried out by continuous mining, fully mechanized mining, and lane mining, while the extremely irregular marginal coal with small area and reserves, such as arc, triangle or sawtooth, which cannot be arranged with regular working faces by comprehensive mechanization, is often abandoned. The main reasons are the difficulty of working face arrangement, the large number of various equipment, the high mining cost, and the existence of safety risks. Therefore, it is extremely important to adopt safe, convenient and feasible methods to mine the residual marginal coal in the mine.

[0004] Solid carbon dioxide is also called dry ice. Dry ice energy rock breaking technology uses the chemical reaction between the energy-gathering agent and carbon dioxide to convert solid carbon dioxide into gaseous carbon dioxide. The phase change process will cause a 600-800 times volume expansion to achieve the purpose of cracking rocks. Compared with liquid carbon dioxide blasting technology, the volume expansion rate is greater. In addition, solid carbon dioxide is relatively convenient to store and transport than liquid carbon dioxide.

[0005] "Research on the Application of Dry Ice Energy Rock Breaking Technology in Tunnel Excavation" published in the Journal of Underground Space and Engineering, Issue 6, 2023, points out that dry ice rock breaking technology has been used in open-pit foundation pits and slope projects. Its rock breaking efficiency is significantly higher than that of mechanical excavation, and it is increasingly used as an effective supplement to traditional rock breaking technologies such as mechanical rock breaking and explosive blasting.

[0006] The Chinese utility model patent with application date of November 15, 2022 and publication number CN115823977A provides a method for efficiently cracking rocks with dry ice, providing a method for cracking rocks that does not require laying cables, can be remotely started, and has better safety and simplicity.

[0007] The Chinese utility model patent with application date of May 8, 2017 and publication number CN106930744A provides a millisecond multi-stage directional blasting dry ice fracturing method and blasting tube, which can effectively control the number of cracks generated, increase the distance of crack extension without causing serious damage to the hole wall, and improve the gas extraction efficiency.

[0008] The Chinese utility model patent with application date of December 28, 2017 and publication number CN207816108U provides a solid carbon dioxide blasting device, which solves the problem of inconvenient fixing of existing equipment.

[0009] The Chinese utility model patent with application date of March 30, 2022 and publication number CN114811404A provides a portable device for storing carbon dioxide underground in coal mines and its use method. The gaseous carbon dioxide formed by the leakage of solid carbon dioxide in the working body can inertify the residual coal in the goaf for fire prevention and fire extinguishing.

[0010] However, existing research and utility models are only applicable to conventional coal mining activities, and do not pay attention to the particularities of edge coal mining, especially the low utilization of carbon dioxide (the use of carbon dioxide for fracturing, blasting, fire prevention and extinguishing, and carbon fixation has not been effectively combined), and there is a lack of prevention methods for using carbon dioxide to simultaneously respond to dynamic disasters and spontaneous combustion. It cannot be applied to the release of "extremely irregular edge coal resources such as arc, triangular or sawtooth shapes with small areas and reserves, and which cannot be arranged into regular working faces using comprehensive mechanization." Utility Model Content

[0011] In order to solve the technical problems existing in the prior art, the utility model provides a marginal coal release device based on solid carbon dioxide, which can fully and gradedly utilize carbon dioxide in different states to release marginal coal and effectively improve the safety level of marginal coal mining areas.

[0012] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is a device for releasing corner coal based on solid carbon dioxide, including a solid carbon dioxide filling mixer truck and a plurality of solid carbon dioxide fracturing carbon removers, the exhaust ends of the plurality of solid carbon dioxide fracturing carbon removers are connected to the adjacent goaf through a first connecting pipe, and the exhaust ends of the plurality of solid carbon dioxide fracturing carbon removers are also connected to the solid carbon dioxide filling mixer truck through a second connecting pipe, and the first connecting pipe and the second connecting pipe are respectively installed with a first carbon removal control valve and a second carbon removal control valve;

[0013] The solid carbon dioxide cracking carbon remover includes a carbon filling tube, a carbon exhaust fan, an air bag and a pressure relief terminal. A plurality of air guide grooves are arranged on the outer tube wall of the carbon filling tube. A pressure relief terminal is installed at the front end of the carbon filling tube, and a sealing terminal is installed at the rear end. A carbon exhaust fan is also installed on the sealing terminal. An air bag is mounted on the outside of the carbon exhaust fan. A carbon exhaust main pipe is installed on the air bag. A first connecting pipe and a second connecting pipe are respectively connected to the carbon exhaust main pipe. The carbon filling tube is filled with a carbon dioxide energy concentrator and solid carbon dioxide. A heating device is also installed in the carbon filling tube. The carbon exhaust fan, the heating device, the first carbon exhaust control valve and the second carbon exhaust control valve are respectively connected to a central controller.

[0014] Preferably, the carbon exhaust fan is an axial flow fan, and a carbon dioxide concentration sensor is installed at the air inlet end.

[0015] Compared with the prior art, the utility model has the following technical effects: In view of the particularity of corner coal mining, the utility model implements multi-stage graded utilization of carbon dioxide in different states, and the safety level of the corner coal mining area is significantly improved. First, the roof is cracked by solid carbon dioxide, which transfers or reduces the pressure of the roof overlying the corner coal. The high-concentration carbon dioxide gas cools, inerts, and suppresses explosions in the adjacent goaf, and simultaneously eliminates the hidden dangers of power disasters and spontaneous combustion. The low-concentration carbon dioxide gas is combined with a filling body containing an alkaline admixture to achieve carbon fixation and sealing. The entire process can be achieved through a set of devices, which can be remotely controlled and have good safety, convenience and economy. It realizes the coordinated and efficient circulation of solid carbon dioxide to eliminate power disasters, high-concentration carbon dioxide gas to eliminate the hidden dangers of spontaneous combustion, solid carbon dioxide mining, and low-concentration carbon dioxide carbon fixation, and scientifically releases the corner coal resources of each block of the mine, and the operation is safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the utility model;

[0017] Figure 2 This is a schematic diagram of the structure of the solid carbon dioxide cracking and carbon removal device in the utility model;

[0018] Figure 3 This is a schematic diagram of the corner coal in the utility model;

[0019] Figure 4 This is a schematic diagram of the cross section of the corner coal in the utility model;

[0020] Figure 5 It is a three-dimensional schematic diagram of the corner coal before solid carbon dioxide is released from the corner coal in the utility model;

[0021] Figure 6 It is a three-dimensional schematic diagram of the corner coal after the solid carbon dioxide in the utility model releases the corner coal. DETAILED DESCRIPTION

[0022] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0023] like Figure 1 and Figure 2 As shown, a device for releasing corner coal based on solid carbon dioxide comprises a solid carbon dioxide filling mixer truck 1 and a plurality of solid carbon dioxide cracking carbon removers 2. The exhaust ends of the plurality of solid carbon dioxide cracking carbon removers 2 are connected to an adjacent goaf 4 via a first connecting pipe 3. The exhaust ends of the plurality of solid carbon dioxide cracking carbon removers 2 are also connected to the solid carbon dioxide filling mixer truck 1 via a second connecting pipe 5. The first connecting pipe 3 and the second connecting pipe 5 are respectively provided with a first carbon removal control valve 7 and a second carbon removal control valve 6.

[0024] The solid carbon dioxide cracking carbon remover 2 in the utility model can be filled by a solid carbon dioxide storage vehicle. The solid carbon dioxide cracking carbon remover 2 blasts the corner coal through the explosive impact force of the internal filling material. At the same time, the generated carbon dioxide gas is collected and processed through the first connecting pipe 3 and the second connecting pipe 5.

[0025] Among them, the solid carbon dioxide cracking carbon remover 2 includes a carbon filling tube 9, a carbon exhaust fan 10, an air bag 11 and a pressure relief terminal 12. A plurality of air guide grooves 13 are arranged on the outer tube wall of the carbon filling tube 9. The front end of the carbon filling tube 9 is equipped with a pressure relief terminal 12, and the rear end is equipped with a sealing terminal 14. The sealing terminal 14 is also equipped with the carbon exhaust fan 10. The outside of the carbon exhaust fan 10 is covered with an air bag 11, and the air bag 11 is equipped with a carbon exhaust main pipe 16. The carbon exhaust main pipe 16 is respectively connected to the first connecting pipe 3 and the second connecting pipe 5. The carbon filling tube 9 is filled with a carbon dioxide energy-gathering agent and solid carbon dioxide. A heating device 17 is also installed in the carbon filling tube 9. The carbon exhaust fan 10, the heating device 17, the first carbon exhaust control valve 7 and the second carbon exhaust control valve 6 are respectively connected to the central controller 18. The solid carbon dioxide cracking carbon remover is a tubular structure, with a heating device installed inside, and filled with carbon dioxide energy-gathering agent and solid carbon dioxide. The two ends of the carbon filling tube 9 are equipped with sealing ends 14 and pressure relief ends 12 to seal the carbon filling tube 9. An air guide groove 13 is arranged on the outer circumference of the carbon filling tube 9. The air guide groove 13 is arranged along the length direction of the carbon filling tube 9. It is used to smoothly suck carbon dioxide into the air bag 11 when the solid carbon dioxide cracking carbon remover 2 is inserted into the borehole. The carbon exhaust fan 10 is used to extract the carbon dioxide gas in the borehole, suck the carbon dioxide gas into the air bag, and transport it to the adjacent goaf 4 or the solid carbon dioxide filling mixer 1 as needed. The carbon exhaust fan 10 is an axial flow fan, and a carbon dioxide concentration sensor 15 is installed at the air inlet end. The carbon dioxide concentration sensor 15 can detect the concentration of carbon dioxide in real time. The central controller 18 controls the first carbon exhaust control valve 7 and the second carbon exhaust control valve 6 according to the concentration of carbon dioxide.

[0026] like Figure 3-Figure 6 As shown, when using it, follow the steps below:

[0027] S1. Accurately identify the small area and reserves of corner coal, survey the occurrence of extremely irregular corner coal such as arc, triangle or sawtooth, which cannot be arranged in a regular working face by comprehensive mechanization, determine the size of each block, and understand the status of the adjacent tunnels and goafs of corner coal;

[0028] S2. Release the corner coal roof:

[0029] a. Drill multiple roof fracturing drill holes 19 in the tunnel along the outer edge of the filling body 22 next to the tunnel toward the top in sequence. Each roof fracturing drill hole 19 reaches the top of the basic roof. The distance between the first roof fracturing drill hole 19 and the last roof fracturing drill hole 19 is greater than the outermost length of the corner coal. The spacing between the roof fracturing drill holes 11 is 2-5 meters, and the drilling angle is 60°-80°.

[0030] b. Use a solid carbon dioxide filling mixer truck 1 to load solid carbon dioxide into a solid carbon dioxide fracturing carbon remover 2, then install the solid carbon dioxide fracturing carbon remover 2 in the roof fracturing borehole 19 in turn, and seal the roof fracturing borehole to prevent carbon dioxide gas leakage and punching after fracturing; the solid carbon dioxide fracturing carbon remover 2 can be connected in parallel or in series, and can be selected according to the hole depth; the filling material in the solid carbon dioxide filling mixer truck 1 is a mixture of paste, slurry, high water, sodium hydroxide, and calcium hydroxide.

[0031] c. The central controller 18 controls the heating device 17 to heat. After the heat generated by the heating device 17 excites the carbon dioxide energy-gathering agent to produce an exothermic reaction, the solid carbon dioxide absorbs the heat released by the combustion of the carbon dioxide energy-gathering agent and quickly changes to a supercritical state, undergoing a phase change and volume expansion. The generated high-pressure carbon dioxide gas rushes out of the pressure relief end, causing fractures in the surrounding rock mass, and reducing the pressure of the roof overlying the corner coal;

[0032] 3-6 milliseconds after the solid carbon dioxide is fractured, the carbon exhaust fan 10 is started to inflate the air bag 11 and fill the top plate fracture drilling hole. At the same time, the carbon exhaust fan 10 sucks the carbon dioxide gas in the top plate fracture drilling hole 19 into the air bag 11 through the air guide groove. During this process, the carbon dioxide concentration sensor 15 detects the carbon dioxide concentration in real time.

[0033] When the carbon dioxide concentration is greater than 34%, the first carbon discharge control valve 7 is opened, and the carbon dioxide gas is discharged into the adjacent goaf 4 to achieve cooling, inerting, and explosion suppression of the goaf;

[0034] When the carbon dioxide concentration is less than 34% and greater than 0.5%, the first carbon discharge control valve 7 is closed, the second carbon discharge control valve 6 is opened, and the carbon dioxide gas is discharged into the solid carbon dioxide filling mixer truck 1;

[0035] When the carbon dioxide concentration is less than 0.5%, the carbon exhaust fan 10, the first carbon exhaust control valve 7, and the second carbon exhaust control valve 6 are closed, the carbon dioxide fracturing carbon exhaust device 2 is taken out from the roof fracturing drilling hole, and the solid carbon dioxide fracturing carbon exhaust device 2 is refilled through the solid carbon dioxide storage vehicle;

[0036] d. Repeat steps b to c until all hidden dangers of roof dynamic disasters and spontaneous combustion in goafs are eliminated;

[0037] S3, side wall of releasing corner coal:

[0038] h. Divide the side wall of the corner coal 8 into several small blocks at intervals of 3-6 meters in the vertical direction of the lane 21 on one side of the corner coal 8, and number the corner coals in sequence from right to left as corner coal 8-1, corner coal 8-2, corner coal 8-3, etc. Drill in the lane in a direction perpendicular to the coal wall to the edge of the corner coal, and arrange the corner coal fracturing drill holes 20; the spacing between the corner coal fracturing drill holes is 0.5-2 meters;

[0039] i. Arrange the solid carbon dioxide cracking carbon remover 2 in each corner coal cracking borehole 20 of the corner coal 8-1, repeat step c, and release part of the coal resources of the corner coal 8-1; then move the solid carbon dioxide cracking carbon remover 2 to the deep part of the corner coal cracking borehole 20, and repeat step c until all the coal resources of the corner coal 8-1 are released; the solid carbon dioxide cracking carbon remover 2 moves 3-5 meters to the deep part of the corner coal cracking borehole each time;

[0040] j. Install a filling retaining wall at the opening of the corner coal 8-1 to form a closed space, inject the filling material in the solid carbon dioxide filling mixer truck into the goaf to form a solid carbon filling body 23 to support the roof, and replenish the filling material into the solid carbon dioxide filling mixer truck 1 in time. After the strength of the solid carbon filling body reaches more than 4MPa, the small block corner coal adjacent to the small block corner coal is mined;

[0041] k. Arrange the solid carbon dioxide fracturing carbon remover in each of the fracturing boreholes of the corner coal 8-2, corner coal 8-3, corner coal 8-4, etc., and repeat steps i and j until all the coal resources of the corner coal are released; carry out mining with 1-3 small pieces of corner coal in between, i.e. first mine the corner coal 8-1, corner coal 8-3, corner coal 8-5, etc., and then fill the corner coal 8-1, corner coal 8-3, corner coal 8-5, etc.; after the strength of the carbon-fixing filling body is stable, mine the corner coal 8-2, corner coal 8-4, corner coal 8-6, etc., and then fill the corner coal 8-2, corner coal 8-4, corner coal 8-6, etc.;

[0042] S4. Repeat S2 and S3 until all the mine's "extremely irregular corner coal with small area and reserves, arc-shaped, triangular or sawtooth-shaped coal that cannot be arranged into regular working faces using comprehensive mechanization" resources are released.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the scope of the present invention.

Claims

1. A device for releasing corner coal based on solid carbon dioxide, characterized in that: It comprises a solid carbon dioxide filling mixer truck and a plurality of solid carbon dioxide fracturing carbon exhausters, wherein the exhaust ends of the plurality of solid carbon dioxide fracturing carbon exhausters are connected to the adjacent goaf through a first connecting pipe, and the exhaust ends of the plurality of solid carbon dioxide fracturing carbon exhausters are also connected to the solid carbon dioxide filling mixer truck through a second connecting pipe, and the first connecting pipe and the second connecting pipe are respectively installed with a first carbon exhaust control valve and a second carbon exhaust control valve; The solid carbon dioxide cracking carbon remover includes a carbon filling tube, a carbon exhaust fan, an air bag and a pressure relief terminal. A plurality of air guide grooves are arranged on the outer tube wall of the carbon filling tube. A pressure relief terminal is installed at the front end of the carbon filling tube, and a sealing terminal is installed at the rear end. A carbon exhaust fan is also installed on the sealing terminal. An air bag is mounted on the outside of the carbon exhaust fan. A carbon exhaust main pipe is installed on the air bag. A first connecting pipe and a second connecting pipe are respectively connected to the carbon exhaust main pipe. The carbon filling tube is filled with a carbon dioxide energy concentrator and solid carbon dioxide. A heating device is also installed in the carbon filling tube. The carbon exhaust fan, the heating device, the first carbon exhaust control valve and the second carbon exhaust control valve are respectively connected to a central controller.

2. A device for releasing corner coal based on solid carbon dioxide according to claim 1, characterized in that: The carbon exhaust fan is an axial flow fan, and a carbon dioxide concentration sensor is installed at the air inlet end.

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