Goaf fire preventing and extinguishing method based on air flow distribution and dry ice phase change

Abstract

The invention discloses a goaf fire preventing and extinguishing method based on wind flow distribution and dry ice phase change. The method comprises the following steps that the wind flow intersection condition of a goaf and a coal face is measured; detecting the influence range when the dry ice is sublimated into CO2 gas in a laboratory; putting dry ice in the goaf; during stoping, after the goaf roof collapses, the goaf roof coal rock falls onto the heat preservation box filled with the dry ice, the heat preservation box is broken, and the dry ice is buried by the goaf roof coal rock and sublimates to form CO2 gas which is diffused all around for fire prevention and extinguishment. According to the method, the heat preservation boxes filled with the dry ice are arranged in the direction parallel to the coal face and are divided into sections according to wind flow intersection in the goaf, and it is guaranteed that CO2 gas formed after sublimation of the dry ice is evenly distributed in the goaf to the maximum extent. The dry ice in the heat preservation box does not generate phase change when being located in a heat dissipation zone, and sublimates after being smashed by goaf roof coal rocks after falling down when being located in an oxidation zone where spontaneous combustion is most likely to happen, and accurate fire prevention and extinguishing are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of fire prevention and extinguishing in coal mine goaf areas, and in particular to a method for fire prevention and extinguishing in goaf areas based on wind flow distribution and dry ice phase change. Background Art

[0002] Most of the coal in my country is mined underground, that is, tunnels are excavated from the ground to the target coal seam and coal mining faces are arranged to mine the coal seam. Affected by factors such as the occurrence conditions and the degree of metamorphism, some coal seams have a tendency to spontaneously combust, which can cause fires under certain conditions, seriously threatening the safe mining of coal. For coal mines with coal seams that are prone to spontaneous combustion, the most likely place for spontaneous combustion of coal fires is the goaf, especially when the amount of coal left in the goaf is large and the air leakage is sufficient. Due to oxygen supply and heat accumulation, the coal left in the goaf is prone to spontaneous combustion and cause secondary disasters.

[0003] At present, the fire prevention and extinguishing methods in goaf include injecting inert gas (N 2 , CO 2 etc.), grouting, spraying of inhibitors, injection of three-phase foam, plugging of air leakage channels and pressure equalization fire prevention and extinguishing. Among them, the injection of inert gas and grouting methods are more commonly used. Both of these fire prevention and extinguishing methods are to arrange pipelines in the tunnel (generally the air intake tunnel) and use the reserved fluid outlet on the pipeline to inject a large amount of fluid into the goaf for fire prevention and extinguishing. That is, the fire extinguishing source is generally concentrated at a certain point in the goaf (on the side of the air intake tunnel). The goaf is diffused and filled by large-scale injection and the use of pores and wind flow distribution in the goaf. This leads to a huge consumption of fire extinguishing materials, uneven distribution of fire extinguishing materials in the goaf, and difficulty in evaluating the fire prevention and extinguishing effect. Especially when there are air leakage channels and structural cracks near the fire extinguishing source, a large amount of fire extinguishing materials will be lost, which will seriously affect the fire prevention and extinguishing effect of the goaf, and then threaten the safe production of the coal mining face. In addition, for the injection of inert gas, when the injection amount is large, it will also cause the oxygen concentration in the air of the coal mining face to decrease, which may cause safety risks such as suffocation of personnel. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a goaf fire prevention and extinguishing method based on wind flow distribution and dry ice phase change.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows:

[0006] A method for preventing and extinguishing fire in goaf based on wind flow distribution and dry ice phase change, comprising the following steps:

[0007] S1. Determination of airflow intersection between goaf and coal mining face:

[0008] S101, after the tracer gas is continuously released at the tracer gas release point in the lower corner area of ​​the coal mining face, the tracer gas will be brought into the goaf under the action of the wind flow, and then enter the coal mining face from the goaf, and finally enter the return air lane;

[0009] S102. In the coal mining face, along the airflow direction, use a tracer gas detector to detect the tracer gas concentration in the airflow at multiple tracer gas concentration detection points under the hydraulic support of the coal mining face, draw a curve of the distance between each tracer gas concentration detection point and the air inlet tunnel and the tracer gas concentration change, and divide the section where the airflow intersects between the coal mining face and the goaf according to the change trend of the curve:

[0010] The first section: the tracer gas concentration is 0, and the wind flow from the coal mining face mainly flows into the goaf;

[0011] The second section: the tracer gas concentration is in a slowly rising section. In this section, the tracer gas concentration is not 0, but does not exceed 100 ppm. In this section, the wind flow from the coal mining face flows into the goaf, and the wind flow from the goaf flows into the coal mining face.

[0012] The third section: the tracer gas concentration is in a rapid rising section. The tracer gas concentration in this section is not 0, and the tracer gas concentration value of the first tracer gas concentration detection point in the section increases by not less than 100% compared with the tracer gas concentration value of the last tracer gas concentration detection point in the second section. This section is mainly composed of goaf airflow merging into the coal mining face;

[0013] S2. Laboratory test of dry ice sublimation into CO 2 Influence range of gas:

[0014] S201. In the laboratory, first, take an incubator, which is a sealed hollow cubic structure. In order to simulate the dry ice being buried after the incubator is broken, the upper cover of the incubator is removed during the experiment, and then dry ice with a mass of M is placed in the incubator, and the incubator is placed at the center of the laboratory floor with the opening facing upward. Coal blocks are laid outside the incubator, and the incubator is buried by piling up the coal blocks. The coal blocks are collected from the coal left in the goaf, and the stacked coal blocks are in the shape of a rectangular parallelepiped as a whole;

[0015] S202, insert multiple CO 2 Gas sensor for measuring CO during sublimation of dry ice 2 Gas concentration;

[0016] All CO 2 The gas sensor is set to the on state, the test conditions are normal temperature and pressure, and the dry ice in the incubator sublimates into CO 2 During the gas process, each CO 2 Gas sensor for measuring CO2 Gas concentration, when measuring CO 2 All CO gas concentrations greater than or equal to 50% 2 Among the gas sensors, select the CO sensor that is farthest from the incubator. 2 The gas sensor uses the distance between it and the incubator as the mass M of dry ice sublimating into CO 2 The diffusion radius of the gas n;

[0017] S3. Dry ice placement in goaf:

[0018] According to the diffusion radius n obtained in step S202 and the section where the wind flow intersects between the coal mining face and the goaf divided in step S102, multiple insulation boxes containing dry ice of mass M are placed into the goaf. At this time, the insulation box is a sealed hollow cube structure, which completely seals and preserves the dry ice. A row of insulation boxes are placed in a direction parallel to the coal mining face, and are placed in sequence from the air inlet to the return airway. The placement principle is:

[0019] In the first section, the distance between adjacent insulation boxes is n;

[0020] In the second section, the distance between adjacent insulation boxes is 1.5n;

[0021] In the third section, the distance between adjacent insulation boxes is 2n;

[0022] S4. During mining, after the roof of the goaf collapses, the coal and rock on the roof of the goaf falls onto the insulated box filled with dry ice, causing the insulated box to rupture. The dry ice is buried by the coal and rock on the roof of the goaf and sublimates to form CO 2 The gas diffuses to the surroundings for fire prevention and extinguishing; as the working face continues to advance, along the advancing direction of the coal mining working face, every time the coal mining working face advances L meters, n≤L≤2n, according to step S3, insulation boxes are placed in the goaf in sequence until the coal mining working face is mined.

[0023] Furthermore, in step S101, the distance between the tracer gas release point and the hydraulic support of the coal mining face is 2m, and is close to the wall of the air intake tunnel.

[0024] Furthermore, in step S101, the tracer gas is SF 6 Or He, the release flow rate of tracer gas is 0.25L / min, and the continuous release time is 10min.

[0025] Furthermore, in step S102, the interval between adjacent tracer gas concentration detection points is 5 m, and each tracer gas concentration detection point is 4 m away from the coal mining face along the advancing direction of the coal mining face and 1.5 m away from the coal seam floor in the vertical direction.

[0026] Further, in step 201, the height h of the heat preservation box is 40cm-50cm, the height H of the stacked coal blocks is 1.5 times-2 times of h, and the overall length and width of the stacked coal blocks are equal and not less than 25m.

[0027] Furthermore, in step S201, the mass M of the dry ice is 15 kg.

[0028] Further, in step S202, the CO 2 The air inlet of the gas sensor is inserted into the coal block to a depth d of 1 cm to 5 cm.

[0029] Furthermore, in step S202, the plurality of CO 2 The gas sensors are arranged in two rows perpendicular to each other and horizontally outside the incubator, and the adjacent two CO 2 The distance between the gas sensors is 2m, and the incubator and the adjacent CO 2 The distance between the gas sensors is also 2m.

[0030] Furthermore, in step S3, the insulated box is deployed using an intrinsically safe drone for coal mines.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) The present invention arranges the insulated boxes filled with dry ice in a direction parallel to the coal mining face and divides the sections according to the intersection of wind flows in the goaf, thereby ensuring that the CO generated after the dry ice sublimates is 2 The uniform distribution of gas in the goaf improves the fire prevention and extinguishing effect.

[0033] (2) The dry ice in the heat preservation box of the present invention does not undergo phase change when it is in the heat dissipation zone. However, when it is in the oxidation zone, which is most prone to spontaneous combustion, and the heat preservation box is broken due to the collapse of coal and rock on the roof of the goaf, the dry ice will sublime, thereby achieving precise fire prevention and extinguishing. The sublimation of dry ice absorbs heat to reduce the surrounding temperature, CO 2 The gas has strong retention capacity, diluting the oxygen concentration around the coal residue, and has a dual effect of inhibiting the spontaneous combustion of the coal residue.

[0034] (3) The dry ice of the present invention is contained in an insulated box, which has a simple structure and low cost. The dry ice is small in weight and easy to place, and the consumption of fire-fighting materials in the whole goaf is small, thereby making the overall cost low. In addition, the insulated box containing dry ice of the present invention is placed by an intrinsically safe drone for coal mines. The placement method is simple, safe and labor-intensive, and effectively avoids the dangers that may be caused by personnel entering the goaf. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1Schematic diagram of the positions of the tracer gas release point and the tracer gas concentration detection point in the embodiment of the present invention;

[0036] Figure 2 The influence range of CO after the laboratory measurement of dry ice sublimation in the embodiment of the present invention 2 Schematic diagram of the installation position of the gas sensor and the thermal insulation box;

[0037] Figure 3 CO in the embodiment of the present invention 2 Schematic diagram of the relative position between the gas sensor air inlet and the incubator;

[0038] Figure 4 This is a schematic diagram of the placement and distribution of thermal insulation boxes in goaf areas in an embodiment of the present invention;

[0039] Figure 5 The distance between each tracer gas concentration detection point and the air inlet tunnel and the tracer gas concentration change curve in the embodiment of the present invention;

[0040] Markings in the figure: 1. Goaf; 2. Coal mining face; 3. Tracer gas release point; 4. Tracer gas concentration detection point; 5. Hydraulic support of coal mining face; 6. Air intake lane; 7. Return air lane; 8. Coal rock on the roof of goaf; 9. Insulation box; 10. CO 2 Gas sensor; 11. Air inlet; 12. Dry ice; 13. Coal. DETAILED DESCRIPTION

[0041] The content of the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments, and the present invention is further elaborated.

[0042] Taking the coal mining face 2 of a mine in Xinzhou, Shanxi as an example, the inclined length of the coal mining face 2 is 150m, the strike length is 800m, and the coal seam has a tendency to spontaneous combustion.

[0043] Reference Figure 1-Figure 4 , a method for preventing and extinguishing fire in goaf based on wind flow distribution and dry ice phase change, comprising the following steps:

[0044] S1, determination of airflow intersection between goaf 1 and coal mining face 2:

[0045] S101, after the tracer gas is continuously released at the tracer gas release point 3 in the lower corner area of ​​the coal mining face 2, the tracer gas will be brought into the goaf 1 under the action of the wind flow, and then enter the coal mining face 2 from the goaf 1, and finally enter the return air lane 7;

[0046] In step S101, the distance between the tracer gas release point 3 and the hydraulic support 5 of the coal mining face is 2m, and it is close to the wall of the air intake tunnel 6;

[0047] In step S101, the tracer gas is SF 6 or He, the release flow rate of the tracer gas is 0.25 L / min, and the continuous release time is 10 min;

[0048] In this embodiment, the tracer gas is SF 6 .

[0049] S102. In the coal mining face 2, along the wind direction, use a tracer gas detector to detect the tracer gas concentration in the wind flow at multiple tracer gas concentration detection points 4 under the hydraulic support 5 of the coal mining face (the interval between adjacent tracer gas concentration detection points 4 is 5m, and each tracer gas concentration detection point 4 is 24m away from the coal mining face along the advancing direction of the coal mining face 2 and 1.5m away from the coal seam floor in the vertical direction), draw a curve of the distance between each tracer gas concentration detection point 4 and the air intake tunnel 6 and the tracer gas concentration change, and divide the section where the wind flow intersects between the coal mining face 2 and the goaf 1 according to the change trend of the curve:

[0050] The first section: the tracer gas concentration is 0, and the wind flow from the coal mining face 2 merges into the goaf 1;

[0051] The second section: the tracer gas concentration is in a slowly rising section. In this section, the tracer gas concentration is not 0, but does not exceed 100 ppm. In this section, the airflow from the coal mining face 2 flows into the goaf 1, and the airflow from the goaf 1 flows into the coal mining face 2.

[0052] The third section: the tracer gas concentration is in a rapid rising section. The tracer gas concentration in this section is not 0, and the tracer gas concentration value of the first tracer gas concentration detection point in the section increases by not less than 100% compared with the tracer gas concentration value of the last tracer gas concentration detection point in the second section. In this section, the wind flow from goaf 1 converges into coal mining face 2.

[0053] like Figure 5 As shown, the coal mining face 2 of a mine in Xinzhou, Shanxi Province in this embodiment is measured, wherein each tracer gas concentration detection point 4 performs three tracer gas concentration detections respectively, and the wind flow intersection between the coal mining face 2 and the goaf 1 is:

[0054] The interval between the tracer gas concentration detection point 4 and the air inlet tunnel 6, which is 0-95m, is the first section; the interval between the tracer gas concentration detection point 4 and the air inlet tunnel 6, which is 95m-120m, is the second section; the interval between the tracer gas concentration detection point 4 and the air inlet tunnel 6, which is 120m-150m to the return air tunnel 7, is the third section.

[0055] S2. Laboratory test of dry ice 12 sublimation into CO 2 Influence range of gas:

[0056] S201. In the laboratory, first take the incubator 9, which is a sealed hollow cubic structure and is made of biodegradable plastic material. In order to simulate the burial of dry ice 12 after the incubator 9 breaks, the upper cover of the incubator 9 is removed during the experiment, and then the dry ice 12 with a mass of M is placed in the incubator 9, and the upper cover of the incubator 9 is placed upward at the center of the laboratory floor. Coal blocks 13 are laid outside the incubator 9, and the incubator 9 is buried by piling up the coal blocks 13. The coal blocks 13 are mined from the coal left in the goaf, and the piled coal blocks 13 are in the shape of a rectangular parallelepiped as a whole; the height h of the incubator 9 is 40cm-50cm, and the height H of the piled coal blocks 13 is 1.5 times-2 times of h, and the overall length and width of the piled coal blocks 13 are equal and not less than 25m. The four sides of the piled coal blocks 13 can be blocked by baffles to form a rectangular parallelepiped shape as a whole.

[0057] In this embodiment, the mass M of the dry ice 12 is specifically 15 kg. The shape of the dry ice 12 is a cubic structure.

[0058] S202, insert multiple CO 2 Gas sensor 10, used to measure CO during sublimation of dry ice 12 2 Gas concentration, the CO 2 The depth d of the gas inlet 11 of the gas sensor 10 inserted into the coal block is 1 cm to 5 cm;

[0059] Specifically, a plurality of the CO 2 The gas sensors 10 are arranged in two rows perpendicular to each other and in the horizontal direction outside the heat preservation box 9, and the distance between two adjacent CO2 gas sensors 10 in each row is 2m. 2 The distance between the gas sensors 10 is also 2 m;

[0060] All CO2 gas sensors 10 are set to the on state, the test conditions are normal temperature and pressure, and the dry ice 12 in the incubator 9 sublimates into CO 2 During the gas process, each CO 2 Gas sensor 10 measures CO 2 Gas concentration, when measuring CO 2 All CO gas concentrations greater than or equal to 50% 2 Among the gas sensors 10, select the CO sensor farthest from the incubator 9. 2 The gas sensor 10 uses the distance between itself and the insulated box 9 as the mass M of dry ice 12 sublimated into CO 2 The diffusion radius n of the gas, the unit of n is meter.

[0061] In this embodiment, the laboratory measured that the insulated box 9 containing 15 kg of dry ice 12 was pre-buried in the coal block, and the dry ice 12 sublimated into CO2 The diffusion radius n of the gas is 10 meters;

[0062] S3, Placement of dry ice 12 in goaf 1:

[0063] According to the diffusion radius n=10 meters obtained in step S202 and the section where the wind flow intersects between the coal mining face 2 and the goaf 1 divided in step S102, a plurality of thermal insulation boxes 9 containing 15 kg of dry ice 12 are placed into the goaf 1 using an intrinsically safe UAV for coal mines. At this time, the thermal insulation boxes 9 are sealed hollow cubic structures, which completely seal and store the dry ice 12. A row of thermal insulation boxes 9 are placed in a direction parallel to the coal mining face 2, and are placed in sequence from the air inlet lane 6 to the return air lane 7. The placement principle is:

[0064] In the first section, the distance between adjacent insulation boxes 9 is n;

[0065] In the second section, the distance between adjacent insulation boxes 9 is 1.5n;

[0066] In the second section, the distance between adjacent insulation boxes 9 is 2n;

[0067] According to step S102, an insulation box 9 filled with dry ice 12 is arranged every 10 m in the first section where the distance between the tracer gas concentration detection point 4 and the air inlet tunnel 6 is 0-95 m;

[0068] In the second section where the distance between the tracer gas concentration detection point 4 and the air inlet tunnel 6 is 95m-120m, an insulated box 9 filled with dry ice 12 is arranged every 15m;

[0069] In the interval from the tracer gas concentration detection point 4 to the air inlet tunnel 6 at a distance of 120 m to the return air tunnel 7, an insulation box 9 filled with dry ice 12 is arranged every 20 m.

[0070] S4. During mining, after the roof of the goaf 1 collapses, the coal rock 8 on the roof of the goaf falls onto the insulation box 9 containing dry ice 12, causing the insulation box 9 to rupture. The dry ice 12 is buried by the coal rock 8 on the roof of the goaf and sublimates to form CO 2 The gas diffuses to the surroundings to extinguish the fire; CO is formed 2The gas diffuses around under the influence of the pressure gradient. Since the dry ice 12 is buried by the coal rock 8 on the roof of the goaf at this time and is limitedly affected by the wind flow, it is not easily carried away by the wind flow after the phase change, which effectively prolongs the time it stays on the surface of the coal body and reduces the amount of it entering the working space of the coal mining face 2, thereby effectively reducing the risk of suffocation of personnel. As the working face continues to advance, along the advancing direction of the coal mining face 2, the coal mining face 2 advances L meters, n≤L≤2n (in this embodiment, L=15 meters), and the insulation box 9 is placed in the goaf 1 in sequence according to step S3 until the mining of the coal mining face 2 is completed.

[0071] The above description is only a preferred embodiment of the present invention, but these embodiments are by no means any limitation to the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any changes made by those skilled in the art in the embodiments of the present invention under the enlightenment of this specification will fall within the scope of the claims of the present invention.

Claims

1. A method for preventing and extinguishing fire in goaf based on wind flow distribution and dry ice phase change, characterized in that: The following steps are involved: S1. Determination of airflow intersection between goaf and coal mining face: S101, after the tracer gas is continuously released at the tracer gas release point in the lower corner area of ​​the coal mining face, the tracer gas will be brought into the goaf under the action of the wind flow, and then enter the coal mining face from the goaf, and finally enter the return air lane; S102. In the coal mining face, along the airflow direction, use a tracer gas detector to detect the tracer gas concentration in the airflow at multiple tracer gas concentration detection points under the hydraulic support of the coal mining face, draw a curve of the distance between each tracer gas concentration detection point and the air inlet tunnel and the tracer gas concentration change, and divide the section where the airflow intersects between the coal mining face and the goaf according to the change trend of the curve: The first section: the tracer gas concentration is 0, and the wind flow from the coal mining face mainly flows into the goaf; The second section: the tracer gas concentration is in a slowly rising section. In this section, the tracer gas concentration is not 0, but does not exceed 100 ppm. In this section, the wind flow from the coal mining face flows into the goaf, and the wind flow from the goaf flows into the coal mining face. The third section: the tracer gas concentration is in a rapid rising section. The tracer gas concentration in this section is not 0, and the tracer gas concentration value of the first tracer gas concentration detection point in the section increases by not less than 100% compared with the tracer gas concentration value of the last tracer gas concentration detection point in the second section. This section is mainly composed of goaf airflow merging into the coal mining face; S2. The scope of influence when the laboratory tests dry ice sublimates into CO2 gas: S201. In the laboratory, first, take an incubator, which is a sealed hollow cubic structure. In order to simulate the burial of dry ice after the incubator is broken, the upper cover of the incubator is removed during the experiment, and then dry ice with a mass of M is placed in the incubator, and the incubator is placed with the opening facing upward at the center of the laboratory floor. Coal blocks are laid outside the incubator, and the incubator is buried by piling up the coal blocks. The coal blocks are collected from the coal left in the goaf, and the stacked coal blocks are in the shape of a rectangular parallelepiped as a whole; S202, inserting a plurality of CO2 gas sensors on the upper surface of the piled coal blocks to measure the CO2 gas concentration when the dry ice sublimates; All CO2 gas sensors are set to be turned on, and the test conditions are normal temperature and pressure. During the process of dry ice in the incubator sublimating into CO2 gas, each CO2 gas sensor measures the CO2 gas concentration. Among all CO2 gas sensors with a measured CO2 gas concentration greater than or equal to 50%, the CO2 gas sensor farthest from the incubator is selected, and the distance between the CO2 gas sensor and the incubator is used as the diffusion radius n of the dry ice with a mass of M sublimating into CO2 gas. S3. Dry ice placement in goaf: According to the diffusion radius n obtained in step S202 and the section where the wind flow intersects between the coal mining face and the goaf divided in step S102, multiple insulation boxes containing dry ice of mass M are placed into the goaf. At this time, the insulation box is a sealed hollow cube structure, which completely seals and preserves the dry ice. A row of insulation boxes are placed in a direction parallel to the coal mining face, and are placed in sequence from the air inlet to the return airway. The placement principle is: In the first section, the distance between adjacent insulation boxes is n; In the second section, the distance between adjacent insulation boxes is 1.5n; In the third section, the distance between adjacent insulation boxes is 2n; S4. During mining, after the roof of the goaf collapses, the coal and rock on the roof of the goaf falls onto the insulated box filled with dry ice, causing the insulated box to rupture. The dry ice is buried by the coal and rock on the roof of the goaf and sublimates to form CO2 gas that spreads around to prevent fire; As the working face continues to advance, along the advancing direction of the coal mining working face, every time the coal mining working face advances L meters, n≤L≤2n, insulation boxes are placed in the goaf in sequence according to step S3 until the coal mining working face is mined.

2. A method for preventing and extinguishing fire in goaf based on wind flow distribution and dry ice phase change as claimed in claim 1, characterized in that: In step S101, the distance between the tracer gas release point and the hydraulic support of the coal mining face is 2m, and it is close to the wall of the air intake tunnel.

3. The method for preventing and extinguishing fire in goaf based on wind flow distribution and dry ice phase change according to claim 1, characterized in that: In step S101, the tracer gas is SF6 or He, the release flow rate of the tracer gas is 0.25 L / min, and the continuous release time is 10 min.

4. The method for preventing and extinguishing fire in goaf based on wind flow distribution and dry ice phase change according to claim 1, characterized in that: In step S102, the interval between adjacent tracer gas concentration detection points is 5 m, and each tracer gas concentration detection point is 4 m away from the coal mining face in the advancing direction of the coal mining face and 1.5 m away from the coal seam floor in the vertical direction.

5. The method for preventing and extinguishing fire in goaf based on wind flow distribution and dry ice phase change according to claim 1, characterized in that: In step 201, the height h of the heat preservation box is 40cm-50cm, the height H of the stacked coal blocks is 1.5 times-2 times of h, and the overall length and width of the stacked coal blocks are equal and not less than 25m.

6. A method for preventing and extinguishing fire in goaf based on wind flow distribution and dry ice phase change as claimed in claim 1, characterized in that: In step S201, the mass M of the dry ice is 15 kg.

7. The method for preventing and extinguishing fire in goaf based on wind flow distribution and dry ice phase change according to claim 1, characterized in that: In step S202, the air inlet of the CO2 gas sensor is inserted into the coal block to a depth d of 1 cm to 5 cm.

8. The method for preventing and extinguishing fire in goaf based on wind flow distribution and dry ice phase change according to claim 1, characterized in that: In step S202, the multiple CO2 gas sensors are arranged in two rows perpendicular to each other and horizontally outside the incubator, and the distance between two adjacent CO2 gas sensors in each row is 2m, and the distance between the incubator and adjacent CO2 gas sensors is also 2m.

9. The method for preventing and extinguishing fire in goaf based on wind flow distribution and dry ice phase change according to claim 1, characterized in that: In step S3, the thermal insulation box is deployed using an intrinsically safe drone for coal mines.

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