Fire prevention and extinguishing system for treating high temperature spontaneous combustion point of coal gangue dump and method thereof

Abstract

The application discloses a kind of governance coal gangue mountain spontaneous combustion high temperature point fire prevention and extinguishing system and method, belong to mine fire protection field, this method first determines high temperature area three-dimensional space position and horizontal directional drilling, again, injects lateral extension and forms three-dimensional network to local high temperature point along temperature gradient tracking with pinnate injection member stretch into multiple injection branch pipe;Then sequentially carry out bottom plugging, lateral surrounding, top covering liquid CO2 injection, form three-dimensional inert gas space, finally inject liquid CO2 with basic slurry, to core area concentrated inertization cooling and acidic gas neutralization;During through temperature field inversion dynamic optimization each branch pipe flow distribution.The application realizes the three-dimensional wrapping and step-by-step closure of high temperature area, eliminates fire extinguishing blind area, effectively inhibits secondary environmental pollution caused by harmful gas leakage, can significantly improve the completeness of fire extinguishing and the long-term effectiveness of fire prevention, realize three-dimensional wrapping, step-by-step closure, intelligent control and collaborative governance integrated fire prevention and extinguishing.

Description

Technical Field

[0001] This invention relates to mine disaster prevention technology, belonging to the field of fire protection, specifically to a fire prevention and extinguishing system and method for controlling spontaneous combustion high-temperature points in coal gangue piles. Background Technology

[0002] Coal gangue, a major solid waste generated during coal mining and washing, forms large piles that are among the most common industrial landmarks in mining areas. During long-term accumulation, the organic matter and other components remaining inside the gangue pile undergo slow oxidation upon contact with air, accumulating internal heat and making the coal gangue pile highly susceptible to spontaneous combustion.

[0003] Currently, conventional methods for controlling spontaneous combustion of coal gangue piles mainly rely on drilling and grouting, and surface spraying. Drilling and grouting technology typically uses a single-pipe direct injection method, pumping the extinguishing grout through the borehole to the depths of the coal gangue pile, relying on the natural flow of the grout in the fissures to cover the high-temperature areas; surface spraying focuses on sealing and covering the slope of the coal gangue pile, attempting to prevent the infiltration of external oxygen.

[0004] The above-mentioned treatment effects are often lower than expected because: 1. The internal pore structure of coal gangue piles is extremely complex. The interior of gangue piles is not a homogeneous medium, but a porous discrete system formed by the mixed accumulation of gangue of different particle sizes. The combustion zone will dynamically migrate with time and airflow direction, which makes the spontaneous combustion source often deeply buried and spatially irregular, and the fire source points highly dispersed. In the traditional single-pipe drilling and injection method, the slurry will preferentially enter along the large cracks with the least resistance, and the coverage area is extremely small. It can only form a local linear or planar coverage, which is difficult to accurately reach and three-dimensionally wrap the deep high-temperature core area. Especially when the fire source is distributed in multiple layers and multiple areas, the treatment of single-pipe drilling and injection will leave a lot of fire extinguishing blind spots. Under the combined effect of internal oxidation and heat storage and external air leakage and oxygen supply, secondary reignition is likely to occur, resulting in repeated treatment work and soaring costs. 2. Existing fire prevention and extinguishing technologies mainly use grouting water or inert gas as extinguishing media. Their mechanism of action focuses on "oxygen isolation and asphyxiation" and "physical heat absorption." This method does not consider the simultaneous treatment of a large amount of acidic harmful gases (such as sulfur dioxide and hydrogen sulfide) generated during the spontaneous combustion of coal gangue. During the water injection or grouting cooling process, the contact between the high-temperature fire source and water will accelerate the water-gas reaction and the escape of acidic gases. These acidic gases not only severely corrode grouting pipelines, valves and other treatment equipment, but also spread with the wind to the surrounding residential areas of the mining area, causing serious secondary environmental pollution.

[0005] 3. Common drilling and grouting operations typically employ direct grouting, meaning grout is injected directly upon encountering the fire source. This lack of a standardized temporal and spatial sequence makes it easy for the grout to leak out along large fissures. In practice, the lack of pre-sealing of the bottom base of the waste rock pile causes significant loss of the injected cooling medium along the bottom pores, making it difficult to accumulate and form an effective impregnated inert layer. Furthermore, the absence of top covering and lateral containment measures allows external air to continuously infiltrate the extinguished area from the surrounding slopes. This disorganized and unlayered grouting method fails to construct a three-dimensional oxygen-barrier curtain that gradually closes from the periphery to the center and from the bottom to the top, making it easy for residual heat sources to reignite through bottom channels or lateral faults, severely weakening the thoroughness and long-term effectiveness of the remediation efforts.

[0006] Therefore, developing a fire prevention and extinguishing system and method that combines precise fire suppression, acid inhibition, and long-term prevention of reignition has become an important direction that urgently needs to be broken through in the field of mine environmental protection and safety. Summary of the Invention

[0007] This solution addresses the problems and needs raised above by proposing a fire prevention and extinguishing system and method for controlling spontaneous combustion high-temperature points in coal gangue piles. The system achieves the aforementioned technical objectives and brings about several other technical benefits due to the adoption of the following technical features.

[0008] To achieve the above objectives, a method for preventing and extinguishing spontaneous combustion high-temperature points in coal gangue piles specifically includes the following steps: S1, determine the three-dimensional spatial location of the high-temperature spontaneous combustion zone of the coal gangue mountain, select a drilling site at the waist of the coal gangue mountain, and perform horizontal directional drilling towards the three-dimensional spatial core location of the high-temperature zone; S2, the feather-shaped injection element is inserted into the high-temperature region and close to the core position. Multiple injection branches in the feather-shaped injection element extend outward in different directions to form a three-dimensional injection network. S3, first inject liquid CO2 into the bottom, side, and top areas in sequence: The injection branch located in the bottom region uses the first flow rate Injecting liquid CO2 for the first duration This creates a high-concentration CO2 inert gas cushion layer beneath the high-temperature region to block the upward flow of oxygen; the injection branch located in the lateral region uses a second flow rate. Liquid CO2 was injected, continuing for the second duration. This creates a ring-shaped curtain around the high-temperature area; the injection branch located at the top uses a third flow rate. Liquid CO2 was injected, continuing for the third time. This causes an inert gas covering layer to form above the high-temperature area; Finally, the total flow rate is injected into all the injection branches. Liquid CO2 and alkaline slurry were injected continuously for the fourth time. This allows for concentrated inerting and cooling of high-temperature areas, as well as neutralization of acidic gases; S4. Temperature sensors at the front end of each injection branch pipe acquire temperature data, and gas concentration sensors at the orifice acquire the concentration of discharged harmful gases. When all temperature data are less than the preset threshold and the concentration of harmful gases is less than the safety threshold, the fire prevention and extinguishing treatment of the spontaneous combustion high-temperature point of the coal gangue mountain is completed.

[0009] In some examples of the present invention, in step S3, the first flow rate The range of values ​​is L / min, first duration The value range is 3-15 min; Second flow The range of values ​​is L / min, second duration The value range is 3-15 min; Third traffic The range of values ​​is L / min, third duration The value range is 3-15 min; Total flow The range of values ​​is L / min, fourth duration The value range is 3-15 min; Flow rate of liquid CO2 Flow rate of alkaline slurry The relationships between them are:

[0010] This is the proportional adjustment coefficient, and its value range is... .

[0011] In some examples of the present invention, after the three-dimensional injection network is formed in step S2, the temperature sensor at the front end of each injection branch pipe obtains the initial temperature data at the corresponding position. The following steps are also included between steps S2 and S3: S2a, setting Basic flow rate value; The duration of synchronous transmission to all injection branches is... A liquid CO2 pulse, and in the subsequent time window Inside, the temperature data of the area where the temperature sensor at the front end of each injection branch is located is collected at the current moment, and the temperature drop rate and temperature recovery delay time at the current moment are obtained based on the initial temperature data; S2b, when the temperature drop rate exceeds the first rate threshold and the temperature rise delay time is lower than the first time threshold, the region where the injection branch is located is determined to be a high-connectivity main channel region; when the temperature drop rate is lower than the second rate threshold and the temperature rise delay time exceeds the second time threshold, the region where the injection branch is located is determined to be a low-connectivity dense region. The first rate threshold is 1.5. The first time threshold is 0.5. ; The second rate threshold is 0.5. The second time threshold is 1.5. ; , The corresponding values ​​are the average temperature drop rate and the average temperature recovery delay time collected from all injection branches at the previous moment; the average initial temperature drop rate and the average temperature recovery delay time are obtained from historical or experimental data. In step S3, adjust the corresponding Basic flow rate values: For the bottom, side, and top regions identified as high-connectivity main channel areas, reduce the corresponding injection branch flow rate. To prevent ineffective escape of the medium; for the bottom, side, and top areas identified as low-connectivity dense zones, the corresponding injection branch pipes should be improved. The dense gangue layer is forcibly split by the explosive effect of instantaneous vaporization and expansion. During the sequential injection of liquid CO2 into the bottom, side, and top regions, the temperature of each region is repeatedly acquired at intervals T. The injection stops when the temperature of that region drops to the region's stopping temperature threshold. Stop injecting traffic into this area when the following occurs; in, The value range is 30-60s. The value range is 3-5 min, and the value range of period T is 5-10 min; the regional stop injection temperature threshold. The value range is ≤40℃.

[0012] In some examples of the present invention, in step S2, when the feather-shaped injector extends into the high-temperature region and approaches the core position, each injector branch adjusts its deflection direction according to the collected coal gangue temperature data, so that the injector branch extends along the direction of increasing temperature gradient in the bottom, side, and top regions.

[0013] In some examples of the present invention, in step S3, liquid CO2 is ejected from the central channel of the nozzle through a first pipe, and alkaline slurry is ejected from the annular channel of the nozzle through a second pipe. After liquid CO2 is ejected from the central channel, it expands and vaporizes instantly. The resulting high-speed aerodynamic force breaks the slurry column ejected from the annular channel into fine droplets with a particle size of 20-80μm. These fine droplets diffuse and penetrate into the fine cracks of the gangue along with the CO2 gas flow, ultimately inertizing and cooling the high-temperature area and neutralizing the acidic gas. Before the injection operation in step S3 begins, the borehole opening is sealed and plugged, and the return gas pipe is connected to continuously collect the harmful gases discharged from the borehole.

[0014] A fire prevention and extinguishing system for controlling the high-temperature spontaneous combustion point of coal gangue piles, comprising: The drilling module is used to determine the three-dimensional spatial location of the high-temperature spontaneous combustion zone of the coal gangue mountain, select a drilling site in the middle of the coal gangue mountain, and perform horizontal directional drilling towards the three-dimensional spatial core location of the high-temperature zone; An extension adjustment module is configured to extend the feather-shaped injection element into the high-temperature region and close to the core position. Multiple injection branches in the feather-shaped injection element 60 extend outward in different directions to form a three-dimensional injection network. The injection control module includes an injection module and a control module. The injection module is used to provide liquid CO2 and alkaline slurry. The control module is configured to sequentially inject liquid CO2 into the bottom, side, and top regions, as well as inject liquid CO2 and alkaline slurry. Among them, the injection branch located in the bottom region uses the first flow rate. Injecting liquid CO2 for the first duration This creates a high-concentration CO2 inert gas cushion layer beneath the high-temperature region to block the upward flow of oxygen; the injection branch located in the lateral region uses a second flow rate. Liquid CO2 was injected, continuing for the second duration. This creates a ring-shaped curtain around the high-temperature area; the injection branch located at the top uses a third flow rate. Liquid CO2 was injected, continuing for the third time. This creates an inert gas covering layer above the high-temperature area; finally, the total flow rate is injected into all the injection branches. Liquid CO2 and alkaline slurry were injected continuously for the fourth time. This allows for concentrated inerting and cooling of high-temperature areas, as well as neutralization of acidic gases; The analysis module is configured to acquire temperature data through temperature sensors at the front end of each injection branch pipe and acquire the concentration of harmful gases discharged through gas concentration sensors at the orifice location. When all temperature data are less than a preset threshold and the concentration of harmful gases is less than a safety threshold, the fire prevention and extinguishing treatment of the spontaneous combustion high-temperature point of the coal gangue mountain is determined to be completed.

[0015] In some examples of the present invention, the insertion adjustment module includes: The feather-shaped injection device has an injection main pipe with a groove at the front and multiple injection branch pipes arranged circumferentially in the groove; Each injection branch is composed of two or more pipe sections connected in series via a drive component, and each injection branch is equipped with a flexible piping component inside. The piping components have a first conduit for liquid CO2 injection and a second conduit for alkaline slurry injection; The rear end of the tube near the drill bit is connected to the injection main tube, while the front end of the tube away from the drill bit is equipped with a temperature sensor and a nozzle that are separated from each other. The nozzle has a central channel for introducing liquid CO2 and an annular channel located outside the central channel for introducing alkaline slurry. Under the action of the nozzle, the liquid CO2 expands and vaporizes instantly after being ejected, and the high-speed aerodynamic force generated breaks the ejected slurry column into fine droplets. The first pipe is connected to the central channel at one end and extends to the outside of the borehole and is connected to the liquid CO2 injection source at the other end. The second pipe is connected to the annular channel at one end and extends to the outside of the borehole and is connected to the alkaline slurry injection source at the other end. The insertion component is configured to connect to the injection main pipe and extend into the high-temperature region and close to the core location.

[0016] In some examples of the present invention, the driving component includes a first driving member, a second driving member, a rotating sleeve, and an electric slip ring; The rotating sleeve is mounted on the front end of the rear section tube via a bearing and is driven to rotate circumferentially by the first driving component; A radially arranged support shaft is fixed at the rear end of the front section tube. This support shaft is rotatably mounted on the rotating sleeve and is driven to rotate by a second driving component. Both the first driving component and the second driving component are combinations of a drive motor and a worm gear mechanism: the first driving component is fixed on the rear section tube, and its output end is connected to the first worm. A first worm wheel is fixed on the rotating sleeve, and the first worm wheel meshes with the first worm. The second driving component is fixed on the rotating sleeve, and its output end is connected to the second worm. A second worm wheel is fixed on the support shaft, and the second worm wheel meshes with the second worm. The power and signal wires in the temperature sensor, the first driving element, and the second driving element are led out through an electric slip ring injected into the branch pipe.

[0017] In some examples of the present invention, the front end of the front section is provided with an independently driven drill bit, which is driven by a hydraulic motor. The power and signal wires are led out through the electric slip ring inside the injection branch pipe; the hydraulic motor's supply and return oil lines are led out independently through the hollow rotary joint inside the injection branch pipe.

[0018] In some examples of the present invention, the injection module includes: A first tank configured to store liquid CO2 is provided with a first output pipe for outputting liquid CO2. The first output pipe is connected to multiple first pipes after being diverted by a flow distribution valve. The second tank is configured to store alkaline slurry and is equipped with a second output pipe for discharging alkaline slurry. The second output pipe is connected to multiple second pipes after being diverted by a flow distribution valve. Multiple first pipes correspond one-to-one with multiple second pipes and are connected to nozzles; Pump sets for medium transportation are installed on the first output pipe and the second output pipe, and valve sets for medium flow regulation are installed on the first pipe and the second pipe.

[0019] Compared with existing technologies, a method for preventing and extinguishing spontaneous combustion high-temperature points in coal gangue piles has the following advantages: 1. After the feather-shaped injection nozzle extends into the high-temperature core area, multiple injection branches extend outward in different directions to form a three-dimensional injection network. This method breaks through the linear / planar limitations of traditional single-pipe direct injection, achieving all-round three-dimensional coverage of the high-temperature area, eliminating blind spots in fire extinguishing from the source, and significantly reducing the risk of secondary reignition. In addition, each injection branch can actively track and extend along the temperature gradient in the bottom, side, and top areas according to the collected coal gangue temperature data, until it reaches the local high-temperature core point in its respective area. It can adaptively adjust the injection point according to the spatial shape of the fire source, so that each injection branch can accurately locate the dispersed fire source points in multiple layers and areas, avoiding the limitations of traditional passive monitoring and static positioning, and greatly improving the treatment effect. 2. Liquid CO2 is injected sequentially into the bottom, sides, and top areas. The bottom is sealed to block the oxygen rising channel, the sides form a ring-shaped curtain, and the top is covered to form a three-dimensional inert gas space. In the central inerting stage, liquid CO2 and alkaline slurry are injected simultaneously into all injection branches within the constructed outer closed space to centrally inertate and cool the high-temperature core area and neutralize acidic gases. This layered, step-by-step injection method can construct a three-dimensional oxygen barrier curtain that is progressively closed from the outside to the center and from the bottom to the top in the deep part, preventing residual heat sources from reigniting from the bottom channels or side cracks, and effectively inhibiting the leakage of harmful gases and causing secondary environmental pollution. It can significantly improve the thoroughness of fire extinguishing and the long-term effectiveness of preventing reignition. In addition, by dynamically optimizing the flow distribution ratio of each branch injection pipe, the efficiency of medium utilization is maximized, realizing overall regional inerting and adaptive precise treatment. 3. Liquid CO2 and alkaline slurry are injected into the high-temperature core area, and a dual-channel Laval nozzle structure is adopted. On the one hand, the adiabatic expansion and vaporization of liquid CO2 when it is ejected from the central channel provides a power source for slurry atomization and achieves physical heat absorption and cooling without the need for additional energy input. The structure is simple and efficient. On the other hand, the alkaline slurry actively penetrates into the cracks in the form of micron-sized atomized droplets with the CO2 airflow, increasing the contact area with acidic gases and improving the reaction efficiency, so as to achieve synergistic treatment of fire extinguishing and cooling and in-situ neutralization of acidic gases. 4. After the liquid CO2 injection in the bottom, side, and top regions is completed, liquid CO2 pulses are synchronously sent to each injection branch pipe. Thermal response data is collected and combined with porosity model inversion to automatically identify the highly connected main channel area and the low-connectivity dense area. For the highly connected area, the injection flow rate is actively reduced to prevent the medium from escaping ineffectively along the cracks; for the low-connectivity dense area, the flow rate is increased and the dense gangue layer is split by the gas explosion effect to open the slurry penetration channel. At the same time, through periodic repeated tests, the cooling status of each zone is dynamically tracked. Injection is stopped immediately after the temperature reaches the target. This method achieves adaptive and precise treatment of "diagnosis first, then action", which not only improves the fire extinguishing efficiency but also effectively avoids medium waste and over-injection.

[0020] A fire prevention and extinguishing system for controlling the high-temperature spontaneous combustion points of coal gangue piles has the following advantages: 1. The injection branch pipe extends outward through the drive component to form a three-dimensional injection network, achieving precise delivery to the high-temperature core point. This makes the injection of liquid inert gas into the spontaneous combustion of coal gangue more precise, effectively solving the problems of deep and dispersed fire sources, irregular combustion areas, and multi-level and multi-area distribution. A single hole can achieve large-scale three-dimensional encapsulation. In addition, the injection branch pipe is equipped with an independently driven drill bit to facilitate temporary crushing. 2. A layered, step-by-step injection procedure is employed, consisting of four sequential actions: bottom sealing, lateral encirclement, top coverage, and central inerting, forming a complete three-dimensional curtain from the outside in and from bottom to top. The bottom is sealed first to block the fundamental oxygen supply channel; lateral encirclement and top coverage then progressively close to form a complete inerting space; finally, the core area is inerted. This sequential logic is scientifically rigorous. The complete three-dimensional curtain completely cuts off the multi-dimensional oxygen supply paths from the outside to the fire zone, significantly improving the thoroughness of fire suppression and the long-term effectiveness in preventing reignition. Attached Figure Description

[0021] Figure 1 This is an overall schematic diagram of the present invention; Figure 2 This is the main view of the injection module in this invention; Figure 3 This is a front view of the feather-shaped injection element extending into the high-temperature region and close to the core position in this invention; Figure 4 This is a front view of the injection branch tube in this invention; Figure 5 yes Figure 4 A magnified view of a portion of position A in the middle; Figure 6 This is a front view of the nozzle in this invention; Figure 7 This is a front view of the injection branch tube extending laterally outward from the injection main tube in the feather-shaped injection device; Figure 8 This is a front view of the injection branch tube in this invention, which includes multiple joint tubes; In the diagram: 10. First tank; 11. First output pipe; 20. Second tank body; 21. Second output pipe; 31. Shut-off valve; 32. Injection pump; 40. Flow distribution valve; 51. First pipeline; 52. Second pipeline; 60. Feather-shaped injection component; 61. Injection main pipe; 611. Groove; 612. Through hole; 62. Injection branch pipe; 621. Support shaft; 622. Joint pipe. 70. Nozzle; 81. Rotating sleeve; 82. Electric slip ring; 83. Sealing cover; 841. First worm; 842. First worm wheel; 851. Second worm; 852. Second worm wheel. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0023] Example 1

[0024] like Figure 1 As shown, a method for preventing and extinguishing fires at high-temperature points of spontaneous combustion in coal gangue piles specifically includes the following steps: S1, determine the three-dimensional spatial location of the high-temperature spontaneous combustion zone of the coal gangue pile, and perform horizontal directional drilling towards that location; S2, the feather-shaped injection member 60 is inserted into the high-temperature region and close to the core position. Multiple injection branches 62 in the feather-shaped injection member 60 extend outward in different directions to form a three-dimensional injection network. S3, first inject liquid CO2 into the bottom, side, and top areas in sequence: The injection branch 62 located in the bottom region uses the first flow rate Injecting liquid CO2 for the first duration This creates a high-concentration CO2 inert gas cushion layer below the high-temperature region to block the upward flow of oxygen; the injection branch 62 located in the lateral region uses a second flow rate. Liquid CO2 was injected, continuing for the second duration. This creates a ring-shaped curtain around the high-temperature area; the injection branch 62 located at the top uses a third flow rate. Liquid CO2 was injected, continuing for the third time. This causes an inert gas covering layer to form above the high-temperature area; Finally, inject the total flow rate into all branch pipes 62. Liquid CO2 and alkaline slurry were injected continuously for the fourth time. This allows for concentrated inerting and cooling of high-temperature areas, as well as neutralization of acidic gases; S4, the temperature sensor at the front end of each injection branch pipe 62 acquires temperature data in real time, and the gas concentration sensor at the orifice acquires the concentration of discharged harmful gas. When all temperature data are less than the preset threshold and the concentration of harmful gas is less than the safety threshold, the fire prevention and extinguishing treatment of the spontaneous combustion high temperature point of the coal gangue mountain is completed.

[0025] Specifically, in step S1, the three-dimensional spatial location of the high-temperature spontaneous combustion zone of the coal gangue pile can be determined by constructing a three-dimensional voxel model, including the following steps: First, a drone equipped with a high-precision infrared thermal imaging sensor is used to conduct a full-coverage mapping of the target coal gangue pile surface, obtaining a two-dimensional temperature distribution map of the coal gangue pile surface and its location information in a geographic coordinate system. Then, based on the abnormally high temperature points in the two-dimensional temperature distribution map, deep exploration boreholes are drilled on the coal gangue pile at a certain grid spacing. Multi-point temperature probes are inserted into the exploration boreholes to measure the internal temperature of the coal body at different depths in real time, thereby obtaining a set of discrete temperature data points of the deep coal body with three-dimensional coordinates. Finally, based on the two-dimensional temperature distribution map of the coal gangue pile surface and the coal body... The discrete temperature data points in the deep part of the coal gangue pile are fused and fitted using statistical interpolation algorithms to construct a three-dimensional voxel model that reflects the internal temperature changes of the coal gangue pile. Based on a preset threshold temperature, continuous high-temperature volume regions are extracted from the three-dimensional voxel model, and their outer boundaries constitute the three-dimensional spatial distribution information of the high-temperature region of spontaneous combustion in the coal pile. Alternatively, the core area of ​​temperature anomalies in the coal gangue pile can be located through a fiber optic temperature measurement system, or the high-temperature anomaly region can be detected through electromagnetic signals, or the high-temperature region can be determined through geometric methods. These are existing technologies and will not be elaborated further. A drilling site was selected on the hillside of the coal gangue mountain, and horizontal directional drilling was carried out using a horizontal directional drilling guide device to reach the designated high-temperature zone; In step S2, the feather injection device 60 consists of an injection main pipe 61 and multiple injection branch pipes 62. The multiple injection branch pipes 62 are arranged circumferentially at the front end of the injection main pipe 61 and are initially hidden inside the injection main pipe 61 to reduce the resistance of the feather injection device 60 extending from the borehole. Under the driving force, the feather-shaped injection component 60 enters the coal gangue pile through the borehole and extends into the high-temperature area and close to the core position. At this time, multiple injection branch pipes 62 extend outward. This extension action can make the injection branch pipe 62 form an angle of 10-80° with the axis of the injection main pipe 61. Each injection branch pipe 62 can be 1-3m long and form a three-dimensional injection network that can cover a radius of 1-5m. In step S3, after the feather injection element 60 reaches the corresponding position, it first uses a first flow rate. Liquid CO2 is injected to enter the bottom sealing stage. This stage uses the highest possible injection flow rate to overcome gravity and forcefully lift and form a high-pressure, high-concentration CO2 inert gas cushion layer directly below the high-temperature region, initially blocking the upward flow of oxygen from the underlying micro-fractures. Then, a second flow rate is used... Liquid CO2 is injected into the lateral envelopment stage. During this stage, with the bottom already sealed, the airflow naturally diffuses upwards and outwards, forming a ring-shaped curtain around the high-temperature area through subsequent injection; then, at a third flow rate... Liquid CO2 is injected into the top covering stage, where an inert gas covering layer is formed above the high-temperature region, thus completing the external sealing of the three-dimensional inert gas space; finally, the total flow rate is... Liquid CO2 and alkaline slurry are injected into the central inerting stage. In this stage, the high-temperature core area is centrally inerted and cooled and the acidic gas is neutralized through all injection branch pipes 62. The minimum flow rate is adopted. On the one hand, it can prevent the instantaneous injection pressure of the mixed medium from being too high and destroying the newly established outer curtain. On the other hand, it can ensure that the atomized droplets of alkaline slurry can slowly and evenly penetrate and react in the dense central core area. To ensure the effectiveness of the injection at each stage, the corresponding traffic needs to meet certain requirements. First traffic The range of values ​​is L / min, first duration The value range is 3-15 min; second flow rate The range of values ​​is L / min, second duration The value range is 3-15 min; the third flow rate The range of values ​​is L / min, third duration The value range is 3-15 min; total flow rate The range of values ​​is L / min, fourth duration The value range is 3-15 min; among which, the flow rate of liquid CO2 Flow rate of alkaline slurry The relationships between them are:

[0026] This is the proportional adjustment coefficient, and its value range is... The corresponding range can be determined according to the atomization particle size requirements of the embodiment.

[0027] In actual operation, the flow rate and duration of each stage can be adaptively and finely adjusted by the control module according to the range of the fire zone and the changes in the temperature field. In step S4, the preset threshold can be 40°C. After all injection branches 62 are injected with alkaline slurry, the temperature sensor collects temperature data of each bottom, side and top area. A gas concentration sensor is installed at the rear end of the feather-shaped injection device 60 and at the orifice position. The gas concentration sensor acquires the concentration of the discharged harmful gas. When all temperature data are less than the preset threshold and the concentration of harmful gas is less than the safety threshold, the fire prevention and extinguishing treatment of the spontaneous combustion high temperature point of the coal gangue mountain is completed.

[0028] In some examples of the present invention, in step S2, when the feather-shaped injection member 60 extends into the high-temperature region and approaches the core position, each injection branch 62 adjusts the deflection direction of the injection branch 62 according to the collected temperature data, so that the injection branch 62 extends along the direction of increasing temperature gradient in the bottom, side and top regions. Specifically, multiple temperature sensors can be installed at the front end of the injection branch pipe 62, for example, four evenly arranged around the perimeter. These temperature sensors can acquire coal temperature data in real time and transmit it to the control unit via wired means to determine the temperature of the high-temperature point. Correspondingly, the control module then controls the injection branch pipe 62 to actively adjust its orientation, so that the injection branch pipe 62 tracks and extends in the direction of increasing temperature gradient until the coal temperature reaches the preset threshold and the temperature gradient no longer increases, or it cannot continue to extend due to excessive resistance. Then it is determined that the high-temperature core point has been reached, which is the target position for directional injection, and the injection branch pipe 62 stops extending. It should be noted that the area extended by the injection branch pipe 62 can be limited by boundary to prevent the injection branch pipe 62 in a certain area from extending into other areas due to the increase in temperature gradient, causing injection overlap and making it impossible to achieve accurate injection in the bottom, side and top areas. That is, by preset the deflection angle limit value and spatial coordinate boundary of each injection branch pipe, when the injection branch pipe 62 touches the preset area boundary, the control module forcibly stops the tracking extension action of the branch pipe.

[0029] In some examples of the present invention, after the three-dimensional injection network is formed in step S2, the temperature sensor at the front end of each injection branch 62 obtains the initial temperature data at the corresponding position. The following steps are also included between steps S2 and S3: S2a, setting Basic flow rate value; The duration of synchronous transmission to all injection branch pipes 62 is... A liquid CO2 pulse, and in the subsequent time window Inside, the temperature data of the area where the temperature sensor at the front end of each injection branch 62 is located is collected at the current moment, and the temperature drop rate and temperature recovery delay time at the current moment are obtained based on the initial temperature data; S2b: The collected thermal response data is input into the preset coal gangue pile porosity model for inversion calculation. When the temperature drop rate exceeds the first rate threshold and the temperature rise delay time is lower than the first time threshold, the area where the injection branch pipe 62 is located is determined to be a high-connectivity main channel area; when the temperature drop rate is lower than the second rate threshold and the temperature rise delay time exceeds the second time threshold, the area where the injection branch pipe 62 is located is determined to be a low-connectivity dense area. The first rate threshold is 1.5. The first time threshold is 0.5. The second rate threshold is 0.5. The second time threshold is 1.5. ; , The corresponding values ​​are the average temperature drop rate and the average temperature recovery delay time collected by all injection branch pipes 62 at the previous moment. The average initial temperature drop rate and the average temperature recovery delay time can be obtained based on previous survey data or experimental results under similar working conditions. In step S3, the injection flow rate of the injection branch pipe 62 is adjusted: for the bottom, side, and top regions identified as high-connectivity main channel areas, the flow rate of the corresponding injection branch pipe 62 is reduced. To prevent ineffective escape of the medium; for the bottom, side, and top regions identified as low-connectivity dense areas, the corresponding injection branch pipe 62 is increased. The dense gangue layer is forcibly split by the explosive effect of instantaneous vaporization and expansion. During the sequential injection of liquid CO2 into the bottom, side, and top regions, the temperature of each region is repeatedly acquired at intervals T. The injection stops when the temperature of that region drops to the region's stopping temperature threshold. Stop injecting traffic into this area when the following occurs; in, The value range is 30-60s. The value range is 3-5 min, and the value range of period T is 5-10 min; the regional stop injection temperature threshold. The value range is ≤40℃; Specifically, this example is used for evaluation and secondary cooling. By reverse-engineering the distribution of pore channels inside the coal gangue pile and dynamically adjusting the flow distribution ratio, liquid CO2 is precisely vaporized and absorbs heat in the high-temperature area deep inside the coal gangue pile, isolating oxygen. At the same time, the alkaline slurry atomized droplets neutralize the acidic harmful gases generated by spontaneous combustion, achieving integrated treatment of rapid fire extinguishing, acid gas suppression and long-term prevention of reignition. In step S2, the temperature sensor obtains the initial temperature data at the corresponding location to facilitate the construction of the initial temperature field model; In step S2a, a probe liquid CO2 pulse is injected to obtain the temperature drop rate and temperature recovery delay time of the area, which facilitates subsequent judgment. In step S2b, the data obtained in step S2a is evaluated. The parameters for each step can be adaptively fine-tuned according to the initial gradient of the on-site temperature field. Preferably, the real-time data collected within the time window can be used to construct a porosity model of the coal gangue pile. By reverse-engineering the distribution of pore channels, fracture development, and fire zone connectivity inside the gangue pile, the flow distribution ratio of each branch injection pipe can be dynamically optimized based on the simulation results to adapt to the precise treatment of fire zones with different pore structures. With time window Taking a 5-minute timeframe and four injection manifolds 62 as an example, the temperature sensor at the front end of each injection manifold 62 collects data at multiple time points within 5 minutes. At the same time, the temperature sensors of the four injection manifolds 62 collect four temperature data points. The average temperature drop rate is calculated based on the four temperature data points. Average temperature rise delay time Using this average value as a benchmark, the four temperature data points collected at the next time step are compared with this average value; that is, when the temperature drop rate in region 62 of the injection branch pipe is greater than 1.5... (i.e., the first rate threshold), and the temperature recovery delay time is less than 0.5. When the temperature reaches the first time threshold, it is determined to be a highly connected main channel region; when the temperature decrease rate is less than 0.5... (i.e., the second rate threshold), and the temperature recovery delay time is greater than 1.5. When the threshold (i.e., the second time threshold) is reached, it is determined to be a low-connectivity dense region, and the injection flow rate of the injection branch 62 is adjusted accordingly.

[0030] In some examples of the present invention, such as Figure 4 , Figure 6As shown, in step S3, liquid CO2 is sprayed out from the central channel of nozzle 70 through the first pipe 51, and alkaline slurry is sprayed out from the annular channel of nozzle 70 through the second pipe 52. After liquid CO2 is ejected from the central channel, it expands and vaporizes instantly. The resulting high-speed aerodynamic force breaks the slurry column ejected from the annular channel into fine droplets with a particle size of 20-80μm. These fine droplets diffuse and penetrate into the fine cracks of the gangue along with the CO2 gas flow, ultimately inertizing and cooling the high-temperature area and neutralizing the acidic gas. In step S3, before the injection of liquid CO2 and alkaline slurry begins, the borehole opening is sealed and plugged, and the return gas pipe is connected so as to continuously collect the harmful gases discharged from the borehole throughout the injection process. Specifically, in step S3, a dual-channel conveying structure is adopted when conveying liquid CO2 and alkaline slurry: liquid CO2 is independently conveyed to nozzle 70 through the first channel, and alkaline slurry is independently conveyed to nozzle 70 through the second channel. When liquid CO2 is sprayed out of nozzle 70, it undergoes adiabatic expansion and vaporization. The vaporization expansion force is used to atomize and break the alkaline slurry into fine droplets and carry them into the gangue fissures, effectively avoiding the problem of freezing and pipe blockage caused by direct contact between slurry and liquid CO2 in the pipeline. The first channel uses a vacuum insulated tube, and the second channel uses a heat-tracing and heat-insulating hose with an outer wall covered with an electric heat tracing tape or a phase change heat storage material layer, which can continuously maintain the slurry delivery temperature at 5-25℃ and prevent the alkaline slurry from freezing; Nozzle 70 is a dual-channel Laval nozzle. After liquid CO2 is ejected from the central channel, it expands and vaporizes instantly. The high-speed aerodynamic force generated breaks the slurry column ejected from the annular channel into fine droplets with a particle size of 20-80μm. When the feather-shaped injection device 60 extends into the high-temperature area and approaches the core position, the orifice is sealed and connected to a return gas pipe. In step S3, the low-temperature CO2 gas generated by the vaporization of liquid CO2 during injection and the acidic harmful gas overflowing from the gangue pile can be drawn out and extracted from the inner wall of the borehole and the return gas pipe for centralized treatment to avoid leakage of harmful gases.

[0031] Example 2

[0032] This fire prevention and extinguishing system for controlling spontaneous combustion high-temperature points in coal gangue piles includes: The drilling module is used to determine the three-dimensional spatial location of the high-temperature spontaneous combustion zone of the coal gangue pile and to perform horizontal directional drilling towards that location; The extension adjustment module is configured to extend the feather-shaped injection member 60 into the high-temperature region and close to the core position. Multiple injection branches 62 in the feather-shaped injection member 60 extend outward in different directions to form a three-dimensional injection network. The injection control module includes an injection module and a control module. The injection module is used to provide liquid CO2 and alkaline slurry. The control module is configured to sequentially inject liquid CO2 into the bottom, side, and top regions, as well as inject liquid CO2 and alkaline slurry. Among them, the injection branch 62 located in the bottom region uses the first flow rate. Injecting liquid CO2 for the first duration This creates a high-concentration CO2 inert gas cushion layer below the high-temperature region to block the upward flow of oxygen; the injection branch 62 located in the lateral region uses a second flow rate. Liquid CO2 was injected, continuing for the second duration. This creates a ring-shaped curtain around the high-temperature area; the injection branch 62 located at the top uses a third flow rate. Liquid CO2 was injected, continuing for the third time. This creates an inert gas covering layer above the high-temperature area; finally, the total flow rate is increased to all injection branch pipes 62. Liquid CO2 and alkaline slurry were injected continuously for the fourth time. This allows for concentrated inerting and cooling of high-temperature areas, as well as neutralization of acidic gases; The analysis module is configured to acquire temperature data in real time through temperature sensors at the front end of each injection branch pipe 62, and acquire the concentration of discharged harmful gases through gas concentration sensors at the orifice location. When all temperature data are less than the preset threshold and the concentration of harmful gases is less than the safety threshold, it is determined that the fire prevention and extinguishing treatment of the spontaneous combustion high-temperature point of the coal gangue mountain has been completed.

[0033] Specifically, this fire prevention and extinguishing system can be integrated into a mobile explosion-proof carrier platform, which is a tracked mining explosion-proof chassis with an explosion-proof rating of not less than Ex db I Mb; The drilling module may include a three-dimensional voxel model for determining the three-dimensional spatial location of the spontaneous combustion high-temperature zone of the coal gangue pile, and a drilling device for drilling operations. This is prior art and will not be further described. The extension adjustment module includes an extension component and a feather-shaped injection component 60. The extension component is a multi-degree-of-freedom robotic arm, which is installed at the front end of the support platform. It is used to clamp the feather-shaped injection component 60 and push it into the borehole according to a preset insertion angle, position and advance speed. When the feather-shaped injection component 60 is pushed to the vicinity of the high-temperature core area, the robotic arm releases the feather-shaped injection component 60 and retracts appropriately. Then, the drive component controls each injection branch pipe 62 to autonomously deflect outward and extend inward. The borehole is equipped with a blowout preventer. Preferably, the robotic arm is a 6-degree-of-freedom hydraulic robotic arm with a maximum load ≥50kg. The injection control module is used to provide the media required for fire extinguishing: liquid CO2 and alkaline slurry, and can switch according to the working environment; the control module is an industrial PLC, which can control the type, flow rate, and duration of media delivery, as well as the start and stop of each injection branch pipe 62 and the flow distribution. The analysis module can be integrated into a computer and connected to the control module to analyze and determine the obtained temperature data, location coordinates, etc. The preset threshold can be 40℃.

[0034] In some examples of the present invention, such as Figure 3 , Figure 4 , Figure 7 , Figure 8 As shown, the insertion adjustment module includes: The insertion component is configured to extend the feather-shaped injection element 60 into the high-temperature region and close to the core location; The feather-shaped injection component 60 has an injection main pipe 61 with a groove 611 at the front and a plurality of injection branch pipes 62 circumferentially located in the groove 611. Each injection branch pipe 62 is connected in series by two or more pipe sections 622 via a drive component; the injection branch pipe 62 is provided with a flexible pipeline component inside; the pipeline component has a first pipe 51 for liquid CO2 injection and a second pipe 52 for alkaline slurry injection. The rear end of the section pipe 622 near the drill hole is connected to the injection main pipe 61, and the front part of the section pipe 622 away from the drill hole is provided with a temperature sensor and a nozzle 70 separated from each other. The nozzle 70 has a central channel for introducing liquid CO2 and an annular channel located outside the central channel for introducing alkaline slurry. Under the action of the nozzle 70, the liquid CO2 expands and vaporizes instantly after being ejected, and the high-speed aerodynamic force generated breaks the ejected slurry column into fine droplets. One end of the pipeline component extends to the outside of the borehole and connects to the corresponding medium source, while the other end connects to the nozzle 70. The insertion component is connected to the injection main pipe 61, extending it into the high-temperature region and close to the core.

[0035] Specifically, the extending component is a multi-degree-of-freedom robotic arm, which is used to clamp the injection main tube 61 and push it into the borehole according to the preset insertion angle, position and advancing speed. When the injection main tube 61 is pushed to the vicinity of the high temperature core area, the robotic arm releases the feather-shaped injection component 60 and retreats appropriately. Then the drive component controls each injection branch tube 62 to autonomously deflect outward and extend in. The injection main pipe 61 serves as an insertion carrier, and its front part is provided with an annular groove 611 or multiple circumferentially arranged grooves 611. The injection branch pipe 62 can be hidden in the groove 611 to reduce the resistance when it is inserted into the borehole. like Figure 8As shown, each injection branch 62 is movably connected by at least two segments 622, which allows the segments 622 to be adjusted in various directions to extend outward in different directions; a drive component is connected between adjacent segments 622 to provide power for this adjustment and extension; the piping components are flexible to accommodate the movable adjustment of the segments 622. Taking each injection branch pipe 62 as having three sections 622, and defining them as a, b, and c from front to back as an example, the rear end of section c is connected to the main injection pipe 61. Section a is provided with multiple temperature sensors for acquiring temperature data and a nozzle 70 for injecting the medium at the front. The temperature sensors are covered with a high-temperature resistant metal protective cover to prevent splashing slurry or condensate from affecting the acquisition accuracy after the medium is injected. Adjacent sections are driven to extend outwards by a driving component. Initially, the axes of sections a, b, and c are aligned and located in the groove 611 of the main injection pipe 61. When the injection branch pipe 62 reaches the high-temperature area and approaches the core position, sections a, b, and c extend outwards from each other under the action of the driving component.

[0036] Furthermore, such as Figure 5 As shown, the driving component includes a first driving member, a second driving member, a rotating sleeve 81, and an electric slip ring 82; The rotating sleeve 81 is rotatably mounted on the front end of the rear section tube 622 via a bearing, and is driven to rotate circumferentially by the first driving component; A radially arranged support shaft 621 is fixed at the rear end of the front section tube 622. The support shaft 621 is rotatably mounted on the rotating sleeve 81 and is driven to rotate by the second driving member. The first and second driving components adopt a worm gear structure, with the drive motor serving as the power source. These components possess high torque and self-locking characteristics. In the first driving component, the drive motor is fixed to the rear section tube 622, and its output end is connected to the first worm 841. A first worm wheel 842 is fixed to the rotating sleeve 81, and the first worm wheel 842 meshes with the first worm 841. In the second driving component, the drive motor is fixed to the rotating sleeve 81, and its output end is connected to the second worm 851. A second worm wheel 852 is fixed to the support shaft 621, and the second worm wheel 852 meshes with the second worm 851. The first driving component is used to adjust the circumferential position of the front section tube 622 relative to the rear section tube 622. The adjustment angle is set to 0-360° according to the actual mechanical limit. Preferably, there are four feather injection elements 60, so the circumferential rotation of the front section tube 622 relative to the rear section tube 622 can be 90° to avoid overlapping injection areas. The second driving component is used to bend and deflect the front section tube 622 relative to the rear section tube 622 in the axial direction. Therefore, the superposition can realize the bending and deflection of the front section tube 622 in various directions. A flexible sealing cover 83 is provided on the outside of the driving component. One end of the sealing cover 83 is rotatably connected to the rear section tube 622, and the other end is connected to the front section tube 622. The slip ring 82 is installed at the front end of the rear section tube 622. It is an electrical component that enables continuous transmission of power and signals in rotating equipment and belongs to the prior art. The wires of the temperature sensor and the drive motor in the second drive unit can be led out from the inside of the branch tube through the slip ring 82. It should be noted that the injection main pipe 61 is provided with a through hole 612 connected to the groove 611 along the axis. On the one hand, the wires led out from the injection branch pipe 62 are bundled and led out from the through hole 612 to the outside of the borehole to facilitate the continuous transmission of power and signals. On the other hand, the pipeline components are also led out from the through hole 612 to the outside of the borehole to facilitate the supply of liquid CO2. The wire bundle and the pipeline components are separated from each other to avoid mutual interference. Furthermore, the front end of the front section pipe 622 may be equipped with an independently driven drill bit, which can be used for temporary crushing deep in the coal body to facilitate the active deflection of the front section pipe 622. The drill bit is driven by a hydraulic motor. The power and signal wires are led out through the electric slip ring 82 inside the injection branch pipe 62. The oil supply and return lines of the hydraulic motor are independently led out through the hollow rotary joint (or hydraulic slip ring) inside the injection branch pipe 62. The two are structurally isolated from each other to avoid oil contamination of the electrical interface.

[0037] In some examples of the present invention, such as Figure 2 As shown, the injection module includes: A first tank 10 configured to store liquid CO2 is provided with a first output pipe 11 for outputting liquid CO2. The first output pipe 11 is connected to multiple first pipes 51 after being diverted by a flow distribution valve 40. The second tank 20 is configured to store alkaline slurry and is provided with a second output pipe 21 for outputting alkaline slurry. The second output pipe 21 is connected to multiple second pipes 52 after being diverted by a flow distribution valve 40. Multiple first pipes 51 correspond one-to-one with multiple second pipes 52 and are connected to nozzles 70; Pump sets for medium transportation are provided on the first output pipe 11 and the second output pipe 21, and valve sets for medium flow regulation are provided on the first pipe 51 and the second pipe 52. Specifically, both the first tank 10 and the second tank 20 are high-pressure containers, and pressure relief valves are installed on the respective tanks; The alkaline slurry is a suspension of sodium bicarbonate powder or limestone powder and water, with a solid phase mass concentration of 10-30% and a solid phase particle size ≤50μm. The first pipe 51 and the second pipe 52 form a group and together provide the corresponding injection medium to the same nozzle 70; Pump sets for media transportation are provided on the first output pipe 11 and the second output pipe 21. The pump sets may include: a shut-off valve 31, a injection pump 32, and other safety valves and other components. The injection pump 32 is used to overcome the long-distance friction resistance from the corresponding tank to the flow distribution valve 40 and to provide a basic delivery pressure to ensure that the medium can reach the flow distribution valve 40 smoothly. It should be noted that the injection pump 32 on the first output pipe 11 is a cryogenic main pump. The flow distribution valve 40 can accurately distribute the input medium to multiple output ports, and is a mature standard industrial product. The first pipe 51 and the second pipe 52 are equipped with valve groups for regulating the flow rate of the medium; that is, on the first pipe 51, the valve group is a low temperature regulating valve and a flow meter; on the second pipe 52, the valve group is a booster pump and a flow meter. Both are independently regulated by the control module to achieve flow distribution in each branch pipe, especially for the injection branch pipe 62 which is determined to be a low-connectivity dense area or a high-connectivity main channel area for precise flow regulation; in addition, to prevent backflow of the medium in the first pipe 51 and the second pipe 52, one-way valves are installed on the corresponding pipes.

[0038] The control module controls the opening and closing of the pump group and valve group, as well as the output power, and switches according to the working environment to complete the type, flow rate, and duration of media transportation, as well as the start and stop of each injection branch pipe 62 and the flow distribution.

[0039] Example 3

[0040] A large coal gangue pile that had been stored for a long time in a large mining area experienced severe spontaneous combustion. Surveys revealed that the source of the fire was deeply buried, with complex pore channels and extremely dispersed fire points, and pungent acidic and harmful gases such as SO2 were continuously emanating from the surface.

[0041] When using traditional drilling and grouting systems that mix water-based slurry with liquid inert gas, the slurry is prone to freezing and clogging the pipeline due to low temperatures. In addition, traditional single-pipe drilling and grouting can only form local linear coverage, and often leaves large areas of air leakage dead zones when facing scattered and irregular fire areas, resulting in "extinguishing the fire but not the poison" and making it very easy for the extinguished embers to reignite.

[0042] To completely eliminate this hidden danger, the mine introduced a fire prevention and extinguishing system for controlling the high-temperature spontaneous combustion point of coal gangue piles, as proposed in this invention. The specific operation steps are as follows: S1. The three-dimensional spatial location of the spontaneous combustion high-temperature zone of the coal gangue mountain is determined by a three-dimensional voxel model. Drilling is carried out by a horizontal directional drilling equipment, and casing is installed to protect the wall depending on the stratum conditions. Drilling is carried out in the middle of the gangue mountain and directly points to the deep high-temperature zone to be measured. S2, using a multi-degree-of-freedom robotic arm on the front of a mobile explosion-proof bearing platform, extends the feather-shaped injection component 60 into the high-temperature area and close to the core position. Upon reaching the high-temperature area, the drive component is activated according to the surrounding environment, controlling the injection branch pipes 62 to extend outward in different directions. During the extension process, the temperature sensor acquires temperature data in real time, and determines the direction of the highest temperature through temperature gradient calculation. Finally, multiple injection branch pipes 62 form an angle with the main injection pipe 61, respectively tracking and reaching the local high-temperature core position in the bottom, side, and top areas. Each injection branch pipe 62 is 2m long. During the extension of the injection branch pipe 62, the drill bit on its front side can be activated according to the working environment. That is, when encountering greater resistance, the drill bit can be used for temporary crushing deep in the coal body to facilitate the active deflection of the front section pipe 622, ultimately forming a three-dimensional injection network with a coverage radius of about 4m. S3, the control module controls the injection of the medium. Each injection branch pipe 62 adopts a dual-channel independent delivery pipeline to deliver different media to the front Laval nozzle 70. Initially, the injection branch pipe 62 located in the bottom area injects liquid CO2 at a first flow rate of 25 L / min. After entering the deep high-temperature area, the liquid CO2 rapidly absorbs heat and vaporizes, and its volume expands rapidly. Since the density of CO2 is greater than that of air, it quickly deposits at the bottom and forms a high-concentration, high-pressure inert gas cushion layer, blocking the oxygen supply channel for fresh air to replenish the fire zone from the micro-cracks below. When the temperature drop rate at the front end of the injection branch 62 in the bottom region is lower than the set threshold or the injection pressure tends to be stable, it is determined that the bottom sealing has been stabilized. The injection branch 62 in the lateral region injects liquid CO2 at a second flow rate of 15 L / min. The vaporized CO2 is sprayed out through the nozzle 70 and diffuses and permeates around the high-temperature core region along the medium flow line. Relying on the expanded three-dimensional injection network, an annular curtain is formed, which effectively cuts off the oxygen supply in the complex pores. Next, liquid CO2 is injected through the injection branch 62 in the top region at a third flow rate of 10 L / min. The vaporized CO2 rapidly diffuses and settles, forming a covering layer at the top of the fire zone. Finally, the bottom inert gas cushion layer, the lateral curtain, and the top covering layer are interconnected, so that the deep spontaneous combustion zone is enclosed in a three-dimensional inert gas space. Finally, in the core treatment phase, all injection branch pipes 62 are activated simultaneously, injecting liquid CO2 and alkaline slurry at a total flow rate of 6 L / min. The alkaline slurry accounts for 30%~50%. The two media enter the central channel of nozzle 70 through the first pipe 51 and the annular channel of nozzle 70 through the second pipe 52, respectively. The two media converge instantaneously, at which point the liquid CO2 undergoes rapid vaporization and expansion, generating high-speed aerodynamic force that breaks up the slurry sprayed from the annular channel, forming a slurry atomization zone and producing fine droplets with a particle size of approximately 50 μm. The alkaline slurry droplets diffuse along the cracks in the gangue with the CO2 airflow, fully contacting and neutralizing acidic harmful gases such as SO2, achieving simultaneous fire extinguishing and toxic gas suppression. S4. In step S3, the temperature sensor at the front of the injection branch pipe 62 acquires temperature data in real time, seals the borehole opening, and collects the gas discharged from the borehole through the return gas pipe. After data analysis, when the temperature in the core area drops from above 400 ℃ to below 40 ℃ and the concentration of harmful gases is below the safety threshold, the system stops operating, the fire prevention and extinguishing system is withdrawn, and the fire prevention and extinguishing treatment of the spontaneous combustion high temperature point of the coal gangue mountain is completed.

[0043] The foregoing description of the exemplary implementation of the method for preventing and extinguishing spontaneous combustion high-temperature points in coal gangue mountains proposed by the present invention refers to preferred embodiments. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the concept of the present invention, and various combinations can be made to the various technical features and structures proposed by the present invention without exceeding the protection scope of the present invention, which is determined by the appended claims.

Claims

1. A method for preventing and extinguishing fires at high-temperature points of spontaneous combustion in coal gangue piles, characterized in that, Specifically, the following steps are included: S1, determine the three-dimensional spatial location of the high-temperature spontaneous combustion zone of the coal gangue mountain, select a drilling site at the waist of the coal gangue mountain, and perform horizontal directional drilling towards the three-dimensional spatial core location of the high-temperature zone; S2, the feather-shaped injection component (60) is inserted into the high-temperature region and close to the core position. Multiple injection branches (62) in the feather-shaped injection component (60) extend outward in different directions to form a three-dimensional injection network. S3, first inject liquid CO2 into the bottom, side, and top areas in sequence: The injection branch (62) located in the bottom region is at the first flow rate Injecting liquid CO2 for the first duration This creates a high-concentration CO2 inert gas cushion layer below the high-temperature area to block the oxygen from rising; the injection branch (62) located in the lateral area uses a second flow rate Liquid CO2 was injected, continuing for the second duration. This creates a ring-shaped curtain around the high-temperature area; the injection branch (62) located at the top area uses a third flow rate. Liquid CO2 was injected, continuing for the third time. This causes an inert gas covering layer to form above the high-temperature area; Finally, the total flow rate is increased to all injection branches (62). Liquid CO2 and alkaline slurry were injected continuously for the fourth time. This allows for concentrated inerting and cooling of high-temperature areas, as well as neutralization of acidic gases; S4, the temperature sensor at the front end of each injection branch pipe (62) acquires temperature data, and the gas concentration sensor at the orifice acquires the concentration of discharged harmful gas. When all temperature data are less than the preset threshold and the concentration of harmful gas is less than the safety threshold, the fire prevention and extinguishing treatment of the spontaneous combustion high temperature point of the coal gangue mountain is completed.

2. The method for preventing and extinguishing fires at high-temperature points of spontaneous combustion in coal gangue piles according to claim 1, characterized in that, In step S3, the first flow rate The range of values ​​is L / min, first duration The value range is 3-15 min; Second flow The range of values ​​is L / min, second duration The value range is 3-15 min; Third traffic The range of values ​​is L / min, third duration The value range is 3-15 min; Total flow The range of values ​​is L / min, fourth duration The value range is 3-15 min; Flow rate of liquid CO2 Flow rate of alkaline slurry The relationships between them are: This is the proportional adjustment coefficient, and its value range is... .

3. The method for preventing and extinguishing fires at high-temperature points of spontaneous combustion in coal gangue piles according to claim 1, characterized in that, After the three-dimensional injection network is formed in step S2, the temperature sensor at the front end of each injection branch (62) obtains the initial temperature data at the corresponding position; The following steps are also included between steps S2 and S3: S2a, setting Basic flow rate value; The duration of synchronous transmission to all injection branches (62) is as follows: A liquid CO2 pulse, and in the subsequent time window Inside, collect the temperature data of the area where the temperature sensor at the front end of each injection branch (62) is located at the current moment, and obtain the current temperature drop rate and temperature recovery delay time based on the initial temperature data; S2b, when the temperature drop rate exceeds the first rate threshold and the temperature rise delay time is lower than the first time threshold, the area where the injection branch (62) is located is determined to be a high-connectivity main channel area; when the temperature drop rate is lower than the second rate threshold and the temperature rise delay time exceeds the second time threshold, the area where the injection branch (62) is located is determined to be a low-connectivity dense area. The first rate threshold is 1.

5. The first time threshold is 0.

5. ; The second rate threshold is 0.

5. The second time threshold is 1.

5. ; , The corresponding values ​​are the average temperature drop rate and the average temperature recovery delay time collected by all injection branches (62) at the previous moment; the average initial temperature drop rate and the average temperature recovery delay time are obtained based on previous survey data or experimental results under similar working conditions. In step S3, adjust the corresponding Basic flow rate values: For the bottom, side, and top regions identified as high-connectivity main channel areas, reduce the corresponding injection branch (62). To prevent the media from escaping unnecessarily; for the bottom, side, and top areas identified as low-connectivity dense zones, the corresponding injection branch pipe (62) should be increased. The dense gangue layer is forcibly split by the explosive effect of instantaneous vaporization and expansion. During the sequential injection of liquid CO2 into the bottom, side, and top regions, the temperature of each region is repeatedly acquired at intervals T. The injection stops when the temperature of that region drops to the region's stopping temperature threshold. Stop injecting traffic into this area when the following conditions are met; in, The value range is 30-60s. The value range is 3-5 min, and the value range of period T is 5-10 min; the regional stop injection temperature threshold. The value range is ≤40℃.

4. The method for preventing and extinguishing fires at high-temperature points of spontaneous combustion in coal gangue piles according to claim 1, characterized in that, In step S2, when the feather-shaped injector (60) extends into the high-temperature area and approaches the core position, each injector branch (62) adjusts the deflection direction of the injector branch (62) according to the collected coal gangue temperature data, so that the injector branch (62) extends along the temperature gradient in the bottom, side and top areas.

5. The method for preventing and extinguishing fires at high-temperature points of spontaneous combustion in coal gangue piles according to claim 1, characterized in that, In step S3, liquid CO2 is ejected from the central channel of nozzle (70) through the first pipe (51), and alkaline slurry is ejected from the annular channel of nozzle (70) through the second pipe (52); After liquid CO2 is ejected from the central channel, it expands and vaporizes instantly. The resulting high-speed aerodynamic force breaks the slurry column ejected from the annular channel into fine droplets with a particle size of 20-80μm. These fine droplets diffuse and penetrate into the fine cracks of the gangue along with the CO2 gas flow, ultimately inertizing and cooling the high-temperature area and neutralizing the acidic gas. Before the injection operation in step S3 begins, the borehole opening is sealed and plugged, and the return gas pipe is connected to continuously collect the harmful gases discharged from the borehole.

6. A fire prevention and extinguishing system for controlling spontaneous combustion high-temperature points in coal gangue piles, characterized in that, include: The drilling module is used to determine the three-dimensional spatial location of the high-temperature spontaneous combustion zone of the coal gangue mountain, select a drilling site in the middle of the coal gangue mountain, and perform horizontal directional drilling towards the three-dimensional spatial core location of the high-temperature zone; The extension adjustment module is configured to extend the feather injection component (60) into the high-temperature region and close to the core position. Multiple injection branches (62) in the feather injection component (60) extend outward in different directions to form a three-dimensional injection network. The injection control module includes an injection module and a control module. The injection module is used to provide liquid CO2 and alkaline slurry. The control module is configured to sequentially inject liquid CO2 into the bottom, side, and top regions, as well as inject liquid CO2 and alkaline slurry. Among them, the injection branch (62) located in the bottom region uses the first flow rate Injecting liquid CO2 for the first duration This creates a high-concentration CO2 inert gas cushion layer below the high-temperature area to block the oxygen from rising; the injection branch (62) located in the lateral area uses a second flow rate Liquid CO2 was injected, continuing for the second duration. This creates a ring-shaped curtain around the high-temperature area; the injection branch (62) located at the top area uses a third flow rate. Liquid CO2 was injected, continuing for the third time. This creates an inert gas covering layer above the high-temperature area; finally, the total flow rate is increased to all injection branches (62). Liquid CO2 and alkaline slurry were injected continuously for the fourth time. This allows for concentrated inerting and cooling of high-temperature areas, as well as neutralization of acidic gases; The analysis module is configured to obtain temperature data through the temperature sensor at the front end of each injection branch pipe (62) and obtain the concentration of discharged harmful gas through the gas concentration sensor at the orifice. When all temperature data are less than the preset threshold and the concentration of harmful gas is less than the safety threshold, it is determined that the fire prevention and extinguishing treatment of the spontaneous combustion high temperature point of the coal gangue mountain is completed.

7. A fire prevention and extinguishing system for controlling spontaneous combustion high-temperature points in coal gangue piles according to claim 6, characterized in that, The insertion adjustment module includes: The feather-shaped injection device (60) has an injection main pipe (61) with a groove (611) at the front, and a plurality of injection branch pipes (62) arranged circumferentially in the groove (611). Each injection branch (62) is connected in series by two or more sections (622) through a drive component, and each injection branch (62) is provided with a flexible pipeline component inside; The piping components have a first conduit (51) for liquid CO2 injection and a second conduit (52) for alkaline slurry injection. The rear end of the section pipe (622) near the drill hole is connected to the injection main pipe (61), and the front part of the section pipe (622) away from the drill hole is provided with a temperature sensor and a nozzle (70) separated from each other; the nozzle (70) has a central channel for introducing liquid CO2 and an annular channel located outside the central channel for introducing alkaline slurry. Under the action of the nozzle (70), the liquid CO2 expands and vaporizes instantly after being sprayed out, and the high-speed aerodynamic force generated breaks the sprayed slurry column into fine droplets; One end of the first pipe (51) is connected to the central channel, and the other end extends to the outside of the borehole and is connected to the liquid CO2 injection source. One end of the second pipe (52) is connected to the annular channel, and the other end extends to the outside of the borehole and is connected to the alkaline slurry injection source. The insertion component is configured to connect to the injection main pipe (61) and extend into the high-temperature region and close to the core location.

8. A fire prevention and extinguishing system for controlling spontaneous combustion high-temperature points in coal gangue piles according to claim 7, characterized in that, The driving component includes a first driving member, a second driving member, a rotating sleeve (81), and an electric slip ring (82). The rotating sleeve (81) is rotatably mounted on the front end of the rear section tube (622) via a bearing, and is driven to rotate circumferentially by the first driving member; The rear end of the front section tube (622) is fixed with a radially arranged support shaft (621), which is rotatably mounted on the rotating sleeve (81) and driven to rotate by a second driving member; Both the first and second driving components are combinations of a drive motor and a worm gear mechanism: the first driving component is fixed on the rear section tube (622), and its output end is connected to the first worm (841). A first worm wheel (842) is fixed on the rotating sleeve (81), and the first worm wheel (842) meshes with the first worm (841); the second driving component is fixed on the rotating sleeve (81), and its output end is connected to the second worm (851). A second worm wheel (852) is fixed on the support shaft (621), and the second worm wheel (852) meshes with the second worm (851). The power and signal wires in the temperature sensor, the first drive unit, and the second drive unit are led out through the electric slip ring (82) inside the injection branch (62).

9. A fire prevention and extinguishing system for controlling spontaneous combustion high-temperature points in coal gangue piles according to claim 7, characterized in that, The front end of the front section (622) is equipped with an independently driven drill bit, which is driven by a hydraulic motor; The power and signal wires are led out through the electric slip ring (82) inside the injection branch pipe (62); the oil supply and return lines of the hydraulic motor are led out independently through the hollow rotary joint inside the injection branch pipe (62).

10. A fire prevention and extinguishing system for controlling spontaneous combustion high-temperature points in coal gangue piles according to any one of claims 7 to 9, characterized in that, The injection module includes: The first tank (10) is configured to store liquid CO2 and is provided with a first output pipe (11) for outputting liquid CO2. The first output pipe (11) is connected to multiple first pipes (51) after being diverted by a flow distribution valve (40). The second tank (20) is configured to store alkaline slurry and is provided with a second output pipe (21) for outputting alkaline slurry. The second output pipe (21) is connected to multiple second pipes (52) after being diverted by a flow distribution valve (40). Multiple first pipes (51) correspond one-to-one with multiple second pipes (52) and are connected to nozzles (70); Pump sets for medium transportation are provided on the first output pipe (11) and the second output pipe (21), and valve sets for medium flow regulation are provided on the first pipe (51) and the second pipe (52).

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