Positive and negative pressure inert gas injection system and method for rapid fire prevention and extinguishing in goaf

Abstract

The invention discloses a positive and negative pressure inert injection system and method for rapid goaf fire prevention and extinguishment, and belongs to the field of goaf fire prevention and extinguishment. The problem that an existing goaf fire extinguishing method is poor in fire extinguishing effect is solved. According to the technical scheme, the device comprises a first air injection main pipe and a plurality of air collecting devices, the air collecting devices are arranged in the first air injection main pipe and are in clearance fit with the first air injection main pipe, the first air injection main pipe is connected to air injection equipment, airflow channels are formed in the air collecting devices in a penetrating mode, and air collecting air inlet parts of the airflow channels are communicated with the first air injection main pipe; the air collecting and discharging part of the airflow channel is connected with a drainage branch pipe, the low-pressure part of the airflow channel is connected to one end of a main drilling pipeline through an air backflow pipeline, the air backflow pipeline is communicated with the airflow channel, the main drilling pipeline is arranged in a goaf, and the other end of the main drilling pipeline is connected to a second air injection main pipe. The effect of rapid fire extinguishing through extraction and injection cooperation is achieved; the method is applied to goaf fire prevention and extinguishing.

Description

Technical Field

[0001] The invention provides a positive and negative pressure injection inerting system and method for rapid fire prevention and extinguishing in goaf areas, belonging to the technical field of fire prevention and extinguishing in goaf areas. Background Art

[0002] As the mining depth of coal mines continues to increase, a large amount of residual coal exists in the goaf during the mining process of the fully mechanized caving working face. The goaf is prone to spontaneous combustion due to air leakage. In the early stage of spontaneous combustion, the method of rapid injection of inert gas can be used to extinguish the fire. By taking advantage of the characteristics of nitrogen that does not support combustion and has a greater density than air, an inert area is formed in the goaf to reduce the oxygen concentration, thereby inhibiting the spontaneous combustion of coal. However, the traditional goaf fire extinguishing method has the following problems: 1. The arrangement of drilling holes is relatively simple, and the three-dimensional space of the goaf is not fully considered, making it difficult to carry out comprehensive and effective fire extinguishing operations in the entire goaf. Usually, drilling holes are only arranged in some key locations, and three-dimensional fire prevention and extinguishing cannot be achieved; Second, due to the limitations of construction conditions and fire-fighting equipment, the inert gas is unevenly distributed and cannot effectively cover the entire fire area, resulting in excessive levels of toxic and harmful gases in the later stage, and in severe cases, may even cause gas explosions; 3. The nitrogen injection speed is slow and the temperature of the ignition area cannot be quickly reduced; 4. The nitrogen injection flow and pressure are difficult to adjust accurately, which affects the fire extinguishing effect. Summary of the invention

[0003] In order to solve the technical problems of poor fire extinguishing effect in existing goaf fire extinguishing methods, the present invention proposes a positive and negative pressure injection inerting system and method for rapid goaf fire prevention and extinguishing, with the purpose of improving the goaf nitrogen injection fire prevention and extinguishing system to increase the fire extinguishing speed and achieve the purpose of efficient fire extinguishing.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a positive and negative pressure injection inert system for rapid fire prevention and extinguishing in goaf areas, comprising a first gas injection main pipe and a plurality of air collecting devices, wherein the first gas injection main pipe is connected to the gas injection equipment, the air collecting device is placed in the first gas injection main pipe, and the air collecting device and the first gas injection main pipe are in clearance fit; The air collecting device is provided with an air flow channel, the air collecting air inlet of the air flow channel is interconnected with the first gas injection main pipe, the air collecting air outlet of the air flow channel is connected with a pumping branch pipe, the low-pressure part of the air flow channel is connected to one end of the main drilling pipe through a gas return pipe, the gas return pipe and the air flow channel are interconnected, the other end of the main drilling pipe is connected to the second gas injection main pipe, and a pressure pump is provided between the second gas injection main pipe and the first gas injection main pipe; The main borehole pipe is provided with a plurality of drainage holes; The main drilling pipeline is placed in the goaf.

[0005] Furthermore, the main drilling pipeline and the second gas injection main pipe are interconnected through a gas injection branch pipe, a sealing cover is provided between the gas injection branch pipe and the main drilling pipeline, and a valve is provided between the gas injection branch pipe and the second gas injection main pipe.

[0006] Furthermore, an exhaust fan is rotatably connected to the gas return duct at the point where it communicates with the air flow channel.

[0007] Furthermore, the cross-sectional areas of the air collecting inlet portion and the air collecting outlet portion on the air flow channel are both larger than the cross-sectional area of ​​the low-pressure portion.

[0008] Furthermore, a plurality of drainage components are arranged in the main borehole pipeline, and the drainage components cooperate with the drainage holes to deliver the gas flowing into the main borehole pipeline into the goaf.

[0009] Furthermore, a gas reflux branch pipe is provided on the main drilling pipeline, and the gas reflux branch pipe is connected to the gas reflux pipeline.

[0010] Furthermore, the first gas injection main pipe and the gas flow channel are parallel to each other.

[0011] Furthermore, the wind collecting devices correspond to the main borehole pipes one by one, and the multiple main borehole pipes are parallel to each other.

[0012] Furthermore, the first gas injection main pipe, the pressure pump, the second gas injection main pipe and the main drilling pipeline form an air flow loop to form a triangular structure.

[0013] A positive and negative pressure injection method for rapid fire prevention and extinguishing in goaf areas adopts the positive and negative pressure injection system for rapid fire prevention and extinguishing in goaf areas to extinguish fire in goaf areas.

[0014] The beneficial effects of the present invention compared with the prior art are as follows: 1. The first gas injection main pipe of the present invention cooperates with the air flow channel of the air collection device to form a low pressure in the low-pressure part of the air flow channel, that is, the air pressure inside the goaf is higher than the air pressure inside the air collection device, thereby generating a siphon effect. Under the action of the exhaust fan, the toxic and harmful gases inside the goaf are efficiently sucked out; 2. The main borehole pipe of the present invention is evenly distributed with a plurality of drainage holes, which cooperate with the drainage components connected inside the main borehole pipe to change the flow direction of the inert gas in the main borehole pipe, and inject the inert gas into the goaf through the drainage holes, so that the inert gas fully covers the goaf, thereby achieving the purpose of isolating oxygen and quickly extinguishing the fire; 3. A valve is connected between the gas injection branch pipe and the second gas injection main pipe of the present invention. The flow rate and flow velocity of the nitrogen gas flowing into the second gas injection main pipe can be controlled by controlling the valve, so as to achieve precise regulation of the flow rate and pressure of the injected inert gas and improve the fire extinguishing effect; 4. The gas injection equipment, air collection device, first gas injection main pipe, second gas injection main pipe, main drilling pipeline and extraction and discharge branch pipe of the present invention cooperate with each other to achieve the effect of rapid fire extinguishing by extraction and injection coordination. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below in conjunction with the accompanying drawings: Figure 1 It is a schematic diagram of the system structure of the present invention; Figure 2 It is a structural schematic diagram of the wind collecting device of the present invention; Figure 3 It is a structural schematic diagram of the main drilling pipeline of the present invention; Figure 4 for Figure 3 Middle AA section view; Figure 5 It is a schematic diagram of the structure of the cooperation between the drainage holes and the drainage baffle; Figure 6 Schematic diagram of wind flow derived from drainage holes; In the figure: 1 is the gas injection equipment, 2 is the air collecting device, 3 is the first gas injection main pipe, 4 is the booster pump, 5 is the valve, 6 is the gas injection branch pipe, 7 is the sealing cover, 8 is the main drilling pipeline, 9 is the drainage hole, 10 is the extraction branch pipe, 11 is the air collection inlet part, 12 is the air collection box, 13 is the low pressure part, 14 is the air flow channel, 15 is the gas return pipeline, 16 is the air inlet, 17 is the exhaust fan, 18 is the air collection outlet part, 19 is the gas return branch pipe, 20 is the drainage baffle, 21 is the second gas injection main pipe, 22 is the connecting part, 23 is the fixing part, and 24 is the goaf. DETAILED DESCRIPTION

[0016] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate relative positions or positional relationships, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0017] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0018] like Figures 1 to 6 As shown, the present invention provides a positive and negative pressure injection inerting system for rapid fire prevention and extinguishing in goaf areas, comprising a first gas injection main pipe 3 and a plurality of air collecting devices 2, the air collecting devices 2 being placed in the first gas injection main pipe 3, and there being a certain distance between the air collecting devices 2 and the first gas injection main pipe 3, so that gas can pass through the gap between the air collecting devices 2 and the first gas injection main pipe 3. The number of air collecting devices 2 is set according to the specific implementation environment, and three are set in this embodiment.

[0019] The first gas injection pipe 3 is connected to the gas injection device 1 , and the gas injection device 1 injects the fire extinguishing gas into the first gas injection pipe 3 . The fire extinguishing gas in this embodiment is an inert gas, specifically nitrogen.

[0020] The air collecting device 2 includes an air collecting box 12, and an air flow channel 14 is provided through the air collecting box 12. The air collecting air inlet 11 of the air flow channel 14 is connected to the first gas injection main pipe 3, and the air collecting air outlet 18 of the air flow channel 14 is connected to the extraction branch pipe 10. The low pressure part 13 of the air flow channel 14 is connected to one end of the main drilling pipe 8 through the gas return pipe 15, and the gas return pipe 15 and the air flow channel 14 are connected to each other. Specifically, the main drilling pipe 8 is connected to a gas return branch pipe 19, and the main drilling pipe 8 is connected to the air inlet 16 on the gas return pipe 15 through the gas return branch pipe 19.

[0021] The main drilling pipe 8 is placed in the goaf 24 , the main drilling pipe 8 corresponds to the wind collecting device 2 one by one, and the plurality of main drilling pipes 8 are parallel to each other.

[0022] The other end of the main drilling pipe 8 is connected to the second gas injection pipe 21, and a booster pump 4 is connected between the second gas injection pipe 21 and the first gas injection pipe 3. The first gas injection pipe 3, the booster pump 4, the second gas injection pipe 21 and the main drilling pipe 8 form an airflow loop. A certain angle is set between the main drilling pipe 8 and the first gas injection pipe 3, and a certain angle is set between the main drilling pipe 8 and the second gas injection pipe 21. The main drilling pipe 8, the first gas injection pipe 3 and the second gas injection pipe 21 form a triangular structure. A number of drainage holes 9 are evenly distributed on the main drilling pipe 8, so that the main drilling pipe 8 is connected to the goaf 24.

[0023] Specifically, the main drilling pipeline 8 and the second gas injection main pipe 21 are interconnected through the gas injection branch pipe 6, and a sealing cover 7 is connected between the gas injection branch pipe 6 and the main drilling pipeline 8. The sealing cover 7 can control the connection and disconnection of the gas injection branch pipe 6 and the main drilling pipeline 8. A valve 5 is connected between the gas injection branch pipe 6 and the second gas injection main pipe 21. The valve 5 is controlled to control the flow rate and flow velocity of the nitrogen flowing into the second gas injection main pipe 21, and cooperates with the main drilling pipeline 8 to make the nitrogen injected into the goaf 24 evenly distributed, thereby achieving the purpose of fully covering the ignition area of ​​the goaf 24 with nitrogen.

[0024] The toxic and harmful gases and residual nitrogen in the goaf 24 are discharged after passing through the main drilling pipeline 8, the gas reflux branch pipe 19, the gas flow channel 14 and the extraction branch pipe 10 in sequence.

[0025] Furthermore, the cross-sectional areas of the air collection inlet 11 and the air collection outlet 18 on the air flow channel 14 are larger than the cross-sectional area of ​​the low-pressure portion 13, so that the air flow channel 14 is narrow in the middle and wide at both ends. The air flow channel 14 is parallel to the first gas injection main pipe 3. When the gas passes through the air flow channel 14 quickly, a low pressure is formed at the connection between the low-pressure portion 13 of the air flow channel 14 and the gas return pipe 15, causing the air pressure inside the goaf 24 to be higher than the air pressure inside the air collection device 2, thereby generating a siphon effect, and then sucking out the toxic and harmful gases inside the goaf 24, and then the residual nitrogen is discharged together with the toxic and harmful gases through the extraction branch pipe 10. The gas return pipe 15 is also rotatably connected to the connection with the air flow channel 14. When the toxic and harmful gases enter the air collection device 2 through the gas return pipe 15, the wind flow drives the exhaust fan 17 to rotate, further improving the efficiency of sucking out the toxic and harmful gases.

[0026] Several drainage components are also connected to the main drilling pipe 8, and the drainage components include several blade-shaped drainage baffles 20. The drainage baffles 20 are fixedly connected with connecting components 22, and the connecting components 22 are fixedly connected to the fixing part 23 on the main drilling pipe 8. The drainage components cooperate with the drainage holes 9. The number of drainage components can be set according to the specific implementation situation. In this embodiment, each drainage component includes three drainage baffles 20. A certain inclination angle is set between the drainage baffles 20 and the main drilling pipe 8 according to the construction situation, so as to accurately send the gas input into the main drilling pipe 8 into the goaf 24. The specific structure of the blade-shaped drainage baffle 20 is a rectangle with an arc on one side. The thickness at the connection with the inner wall of the main drilling pipe 8 is greater than the thickness at the inner wall away from the main drilling pipe 8, which is convenient for changing the gas flow direction.

[0027] The present invention also provides a positive and negative pressure injection method for rapid fire prevention and extinguishing in goaf areas, and the goaf area 24 is extinguished by using the positive and negative pressure injection system for rapid fire prevention and extinguishing in goaf areas.

[0028] The working principle of the present invention is: When the goaf 24 catches fire, the gas injection equipment 1, the pressure pump 4 and the sealing cover 7 are turned on, and the valve 5 is adjusted to allow the inert gas to be quickly injected into the first gas injection main pipe 3. The inert gas is divided into two paths in the first gas injection main pipe 3. One path quickly passes through the air flow channel 14 of the wind collecting device 2. Based on the Venturi effect, a low pressure is formed in the low pressure part 13 of the wind collecting device 2, causing the air pressure inside the goaf 24 to be higher than the air pressure inside the wind collecting device 2. The toxic and harmful gases inside the goaf 24 are sucked out through the main drilling pipeline 8, the gas return branch pipe 19 and the gas return pipeline 15, and discharged through the extraction branch pipe 10; one path passes through the gap between the wind collecting device 2 and the first gas injection main pipe 3, and a part of it is injected into the next wind collecting device 2, and the rest passes through the collecting device 2. The booster pump 4 is injected into the gap between the wind device 2 and the first gas injection main pipe 3. After the pressure is increased by the booster pump 4, it is injected into the goaf 24 through the second gas injection main pipe 21, multiple main drilling pipes 8 and drainage holes 9 in turn, so that the nitrogen can effectively and comprehensively cover the goaf 24 to isolate oxygen. The toxic and harmful gases inside the goaf 24 and the remaining nitrogen are released through the main drilling pipe 8, the gas reflux branch pipe 19, the wind collecting device 2 and the extraction branch pipe 10, forming a gas flow cycle, so as to achieve the purpose of coordinated fire extinguishing by extraction and injection.

[0029] Regarding the specific structure of the present invention, it should be noted that the connection relationship between the various component modules adopted in the present invention is definite and feasible. Except for special instructions in the embodiments, the specific connection relationship can bring about corresponding technical effects, and solve the technical problems raised by the present invention without relying on the execution of corresponding software programs. The components, modules, models of specific components, the connection methods between each other, and the conventional use methods and expected technical effects brought about by the above-mentioned technical features, except for specific instructions, all belong to the disclosed contents in patents, journal articles, technical manuals, technical dictionaries, and textbooks that can be obtained by technical personnel in this field before the application date, or belong to the existing technologies such as conventional technologies and common knowledge in this field, and there is no need to elaborate, so that the technical solution provided in this case is clear, complete, and feasible, and the corresponding physical products can be reproduced or obtained according to the technical means.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A positive and negative pressure injection system for rapid fire prevention and extinguishing in goaf areas, characterized in that: It comprises a first gas injection main pipe (3) and a plurality of air collecting devices (2), wherein the first gas injection main pipe (3) is connected to the gas injection equipment (1), the air collecting devices (2) are placed in the first gas injection main pipe (3), and the air collecting devices (2) and the first gas injection main pipe (3) are clearance-matched; The air collecting device (2) is provided with an air flow channel (14) running through it, the air collecting air inlet portion (11) of the air flow channel (14) is in communication with the first gas injection main pipe (3), the air collecting air outlet portion (18) of the air flow channel (14) is connected to the extraction branch pipe (10), the low pressure portion (13) of the air flow channel (14) is connected to one end of the main drilling pipe (8) through a gas return pipe (15), the gas return pipe (15) and the air flow channel (14) are in communication with each other, the other end of the main drilling pipe (8) is connected to the second gas injection main pipe (21), and a pressure pump (4) is provided between the second gas injection main pipe (21) and the first gas injection main pipe (3); The main borehole pipe (8) is provided with a plurality of drainage holes (9); The main borehole pipeline (8) is placed in the goaf (24).

2. The positive and negative pressure injection system for rapid fire prevention and extinguishing in goaf according to claim 1 is characterized in that: The main drilling pipeline (8) and the second gas injection main pipeline (21) are connected to each other via a gas injection branch pipeline (6); a sealing cover (7) is provided between the gas injection branch pipeline (6) and the main drilling pipeline (8); and a valve (5) is provided between the gas injection branch pipeline (6) and the second gas injection main pipeline (21).

3. The positive and negative pressure injection inerting system for rapid fire prevention and extinguishing in goaf according to claim 1 is characterized in that: The gas return pipe (15) is also rotatably connected to an exhaust fan (17) at the point where it communicates with the gas flow channel (14).

4. The positive and negative pressure injection system for rapid fire prevention and extinguishing in goaf according to claim 1 is characterized in that: The cross-sectional areas of the air collecting inlet portion (11) and the air collecting outlet portion (18) on the air flow channel (14) are both greater than the cross-sectional area of ​​the low-pressure portion (13).

5. The positive and negative pressure injection system for rapid fire prevention and extinguishing in goaf according to claim 1 is characterized in that: A plurality of drainage components are arranged in the main borehole pipeline (8), and the drainage components cooperate with the drainage holes (9) to deliver the gas flowing into the main borehole pipeline (8) into the goaf (24).

6. The positive and negative pressure injection inerting system for rapid fire prevention and extinguishing in goaf according to claim 1 is characterized in that: The main drilling pipeline (8) is provided with a gas return branch pipe (19), and the gas return branch pipe (19) is connected to the gas return pipeline (15).

7. The positive and negative pressure injection system for rapid fire prevention and extinguishing in goaf according to claim 1 is characterized in that: The first gas injection main pipe (3) and the gas flow channel (14) are parallel to each other.

8. The positive and negative pressure injection inerting system for rapid fire prevention and extinguishing in goaf according to claim 1 is characterized in that: The wind collecting devices (2) correspond to the main borehole pipes (8) one by one, and the plurality of main borehole pipes (8) are parallel to each other.

9. The positive and negative pressure injection inerting system for rapid fire prevention and extinguishing in goaf according to claim 1 is characterized in that: The first gas injection main pipe (3), the booster pump (4), the second gas injection main pipe (21) and the main drilling pipe (8) form an air flow loop, forming a triangular structure.

10. A positive and negative pressure injection method for rapid fire prevention and extinguishing in goaf areas, characterized in that: The goaf (24) is extinguished by using the positive and negative pressure injection inerting system for rapid fire prevention and extinguishing in goaf as described in any one of claims 1 to 9.

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