Longwall top coal caving system, residual coal fire prevention and extinguishment treatment system and method

Abstract

This application discloses a longwall top coal caving mining system, a residual coal fire prevention and extinguishing system, and a method. The residual coal fire prevention and extinguishing system includes: a slurry supply system; a spraying system comprising multiple spraying units, each including a nozzle and a slurry control valve, each spraying unit corresponding to at least one hydraulic support, the hydraulic support being equipped with a first pressure detection device for detecting the oil pressure in the return oil pipeline of the rear scraper conveyor of the hydraulic support; and a control device electrically connected to the slurry supply system, the slurry control valve, and the first pressure detection device, to control the operation of the slurry supply system and the opening and closing of the multiple slurry control valves based on the pressure signal detected by the first pressure detection device, and to control the slurry control valves to close after the opening time reaches a preset duration when the slurry control valves are opened. The residual coal fire prevention and extinguishing system of this application provides sufficient slurry spraying and achieves good fire prevention and extinguishing effects.

Description

Technical Field

[0001] This application relates to the field of fire prevention and control technology in coal mining faces, and in particular to a fire prevention and control system for residual coal behind hydraulic supports in longwall top coal caving mining, a method for fire prevention and control of residual coal behind hydraulic supports in longwall top coal caving mining, and a longwall top coal caving mining system. Background Technology

[0002] In coal mining, goaf fires have always been a major hidden danger threatening mine safety. Especially in longwall mining with top-coal caving, coal residue left behind by hydraulic supports is a significant contributing factor to goaf fires. Therefore, fire prevention and extinguishing measures for coal residue left behind by hydraulic supports are crucial for preventing goaf fires.

[0003] Fire prevention and extinguishing of coal residue behind hydraulic supports typically involves spraying fire-retardant materials onto the coal residue to form an oxygen-barrier, heat-absorbing, and cooling protective layer on its surface. However, current techniques lack intelligent spraying of these materials, and the spraying time is short, resulting in incomplete coverage of the coal residue surface. Consequently, the fire prevention and extinguishing effects of existing hydraulic support methods for coal residue prevention and extinguishing are unsatisfactory. Summary of the Invention

[0004] This application aims to at least solve one of the technical problems existing in the prior art. To this end, this application discloses a fire prevention and extinguishing system for residual coal behind hydraulic supports in longwall top coal caving mining. The system includes: a slurry supply system for supplying fire extinguishing slurry; and a spraying system for spraying the fire extinguishing slurry toward the residual coal. The spraying system includes multiple spraying units, each including at least one nozzle and a slurry control valve for controlling the connection between the nozzle and the slurry supply system. The multiple spraying units are arranged sequentially and at intervals along the extension direction of the coal face so that the spraying range of the multiple spraying units can cover all the residual coal behind the hydraulic supports of the coal face. Each spraying unit corresponds to at least one hydraulic support, and the spraying range of each spraying unit is... The enclosure can cover the residual coal behind the corresponding hydraulic support. At least one of the hydraulic supports in the same spraying unit is equipped with a first pressure detection device. The first pressure detection device is used to detect the oil pressure in the return oil pipeline of the rear scraper conveyor of the hydraulic support to determine whether the rear scraper conveyor is being pulled towards the base of the hydraulic support. A control device is electrically connected to the slurry supply system, the spraying control valve and the first pressure detection device to control the operation of the slurry supply system and the opening and closing of multiple spraying control valves according to the pressure signal detected by the first pressure detection device. When the spraying control valve is opened, it is closed after the opening time reaches a preset time.

[0005] Furthermore, when the hydraulic supports corresponding to the same spraying unit include a first hydraulic support, a second hydraulic support, a third hydraulic support, and a fourth hydraulic support arranged sequentially along the extension direction of the coal mining face, the nozzle includes a first nozzle and a second nozzle. The first nozzle is adapted to be disposed on the front connecting rod of the first hydraulic support, and the second nozzle is adapted to be disposed on the front connecting rod of the third hydraulic support.

[0006] Furthermore, an intake airway and a return airway are respectively arranged on both sides of the coal mining face. The slurry supply system is located in the intake airway. The last slurry control valve among the plurality of slurry control valves along the extension direction of the coal mining face includes a first valve port and a second valve port that can be switched on and off. The remaining slurry control valves each include a first valve port, a second valve port, and a third valve port, and the first valve port can be selectively connected to one of the second valve port and the third valve port. The fire prevention and extinguishing system also includes: a slurry conveying main pipe, one end of which is connected to the slurry supply system. The first valve port of the first slurry control valve among the plurality of slurry control valves along the extension direction of the coal mining face is connected to the other end of the slurry conveying main pipe. The second valve port of each slurry control valve is connected to the corresponding nozzle. The third valve port of the first slurry control valve among two adjacent slurry control valves in the extension direction of the coal mining face is connected to the first valve port of the second slurry control valve through a slurry conveying sub-pipe.

[0007] Further, the slurry supply system includes: a storage silo, which defines a storage cavity for storing materials; a mixing silo, which defines a mixing cavity, and has a water inlet, a feeding port, and a slurry outlet communicating with the mixing cavity; a material conveying device, which is connected between the storage silo and the feeding port to quantitatively convey the materials stored in the storage silo to the mixing cavity; a water supply assembly, which is connected between the water source and the water inlet to quantitatively supply water to the mixing cavity; and a slurry conveying pump, whose inlet end is connected to the slurry outlet and whose outlet end is connected to one end of the slurry conveying main pipe. The material conveying device, the water supply assembly, and the slurry conveying pump are all electrically connected to the control device.

[0008] Furthermore, the mixing chamber is equipped with a liquid level detection device for detecting the liquid level in the mixing chamber. The liquid level detection device is electrically connected to the control device. When the liquid level value detected by the liquid level detection device is greater than or equal to a preset liquid level threshold, the control device controls the water supply component to stop supplying water and controls the material conveying device to stop conveying materials. When the liquid level value detected by the liquid level detection device is less than the preset liquid level threshold within a preset observation period, the control device controls the water supply component to start supplying water and controls the material conveying device to start conveying materials.

[0009] Furthermore, the water supply assembly includes a first flow detection device for detecting the water supply flow rate. The first flow detection device is electrically connected to the control device. When the water supply flow rate detected by the first flow detection device is less than a first preset flow rate threshold, the control device controls the material conveying device to stop material conveying and controls the slurry conveying pump to stop slurry conveying.

[0010] Furthermore, a second flow detection device for detecting the slurry conveying flow rate is provided between the outlet end of the slurry conveying pump and one end of the slurry conveying main pipe. The second flow detection device is electrically connected to the control device. When the slurry conveying flow rate detected by the second flow detection device is less than a second preset flow rate threshold, the control device controls the material conveying device to stop material conveying and controls the water supply component to stop water supply.

[0011] Furthermore, the mixing silo also has an overflow port communicating with the mixing chamber. The fire prevention and extinguishing system further includes: a second pressure detection device for detecting the pressure at the outlet of the slurry conveying pump; an overflow pipe, one end of which is connected to the outlet of the slurry conveying pump, and the other end of which is connected to the overflow port; and an overflow valve located between the other end of the overflow pipe and the overflow port. Both the second pressure detection device and the overflow valve are electrically connected to the control device. When the slurry conveying pressure value detected by the second pressure detection device is greater than or equal to a preset pressure threshold, the control device controls the overflow valve to open.

[0012] This application also discloses a longwall top coal caving mining system, comprising: multiple hydraulic supports, the multiple hydraulic supports being arranged sequentially along the extension direction of the coal mining face, each hydraulic support including a base and a rear scraper conveyor, the rear scraper conveyor being located at the rear of the base and being able to be pulled toward the base; and a fire prevention and extinguishing system for residual coal behind the hydraulic supports in any of the above embodiments.

[0013] This application also discloses a method for preventing and extinguishing fires in residual coal after hydraulic support frames in longwall top coal caving mining. The method employs the hydraulic support frame residual coal fire prevention and extinguishing system described in any of the above embodiments. The method includes: a control device acquiring the number and position of hydraulic supports whose rear scraper conveyors are pulled towards the base based on pressure signals from all the first pressure detection devices; and, upon detecting that a rear scraper conveyor is being pulled towards the base, activating the slurry supply system to prepare fire-extinguishing slurry; and, based on the detected number and position of the hydraulic supports, controlling the spraying unit corresponding to the detected hydraulic support to spray the slurry according to a set pattern. The supply system is switched on and off, wherein the setting mode is as follows: when there is one spraying unit corresponding to the detected hydraulic support, the spraying unit is controlled to connect with the slurry supply system so that the spraying unit can spray fire extinguishing slurry towards the residual coal, and when the spraying time reaches the preset time, the spraying unit is controlled to disconnect from the slurry supply system to stop spraying; when there are multiple spraying units corresponding to the detected hydraulic support, multiple spraying units are controlled to connect with the slurry supply system sequentially along the extension direction of the coal mining face, and when the next spraying unit connects with the slurry supply system, the previous spraying unit disconnects from the slurry supply system, and the duration of each spraying unit's connection with the slurry supply system is the preset time.

[0014] Compared with the prior art, the fire prevention and extinguishing system for residual coal after hydraulic support in longwall top coal caving mining of this application has at least the following beneficial effects:

[0015] The control device controls the operation of the slurry supply system and the opening and closing of multiple spraying control valves based on the pressure signal detected by the first pressure detection device. Specifically, the fire prevention and extinguishing system for residual coal behind the hydraulic support in this application uses the pulling of the rear scraper conveyor towards the base as a trigger condition to initiate the automatic spraying program of the fire prevention and extinguishing slurry, thereby automating the fire prevention and extinguishing of residual coal behind the hydraulic support. Using the pulling of the rear scraper conveyor towards the base as a trigger condition ensures that all coal blocks above the hydraulic support fall and accumulate below the tail beam to form residual coal behind the support when spraying the fire prevention and extinguishing slurry, thus avoiding the problem of some coal blocks not falling into the slurry spraying range. Furthermore, by ensuring that the spraying control valve remains open for a preset time before closing, it is guaranteed that the spraying unit can fully spray the residual coal behind the support, ensuring that the fire prevention and extinguishing slurry can fully cover the residual coal, resulting in thorough spraying and good fire prevention and extinguishing effect. Furthermore, the control device has a recording function, which can record the position and number of hydraulic supports in all hydraulic supports where the rear scraper conveyor is pulled towards the base. Based on the recorded information, it controls the slurry control valves of multiple corresponding spraying units to open sequentially for a preset duration. This not only ensures the spraying pressure of each spraying unit but also the spraying duration of each spraying unit, thereby ensuring that each spraying unit can fully spray the residual coal behind its corresponding support.

[0016] The longwall top coal caving mining system of this application, by including the hydraulic support frame rear coal fire prevention and extinguishing system for longwall top coal caving mining of any of the above embodiments, has all the advantages of the above hydraulic support frame rear coal fire prevention and extinguishing system, which will not be repeated here.

[0017] The method for preventing and extinguishing fires of residual coal behind hydraulic supports in longwall top coal caving mining of this application, by adopting the fire prevention and extinguishing system for residual coal behind hydraulic supports of any of the above embodiments, has all the advantages of the above-mentioned fire prevention and extinguishing system for residual coal behind hydraulic supports, which will not be repeated here.

[0018] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0019] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0020] Figure 1 This is a schematic diagram of a longwall top coal caving mining system according to an embodiment of this application;

[0021] Figure 2This is a schematic diagram of a longwall top coal caving mining system according to an embodiment of this application;

[0022] Figure 3 This is a schematic diagram of a longwall top coal caving mining system according to an embodiment of this application;

[0023] Figure 4 This is a schematic diagram of a longwall top coal caving mining system according to an embodiment of this application;

[0024] Figure 5 This is a structural schematic diagram of the fire prevention and extinguishing system for residual coal after the structure is erected, according to an embodiment of this application.

[0025] Figure 6 yes Figure 5 The diagram shows the slurry supply system of the coal residue fire prevention and extinguishing system shown in the figure.

[0026] Figure 7 yes Figure 5 The diagram shows a spraying system for the fire prevention and extinguishing system for coal residue behind the frame.

[0027] Figure 8 This is a schematic diagram of the nozzle assembly of the coal residue fire prevention and extinguishing system according to an embodiment of this application installed on the front connecting rod of the hydraulic support. Only a partial structure of the front connecting rod of the hydraulic support is shown in the figure.

[0028] Figure 9 yes Figure 8 A plan view of the nozzle assembly shown;

[0029] Figure 10 yes Figure 8 An exploded view of a portion of the nozzle assembly shown in the diagram;

[0030] Figure 11 yes Figure 8 The three-dimensional view of the nozzle assembly shown indicates that the nozzle of the nozzle is facing a first orientation;

[0031] Figure 12 yes Figure 8 The perspective view of the nozzle assembly shown shows the nozzle of the nozzle facing a second orientation;

[0032] Figure 13 yes Figure 8 The diagram shows a perspective view of the nozzle assembly, with the nozzle of the nozzle facing a third position.

[0033] Figure label:

[0034] Longwall top coal caving mining system 1000; Coal face 1001; Goaf 1002; Residual coal 1003; Coal lump 1004; Gangue 1005; Underground water supply network 1006; Post-support residual coal fire prevention and extinguishing system 100; Slurry supply system 10; Storage silo 11; Mixing silo 12; Water inlet 121; Feeding port 122; Slurry outlet 123; Material conveying device 13; Water supply assembly 14; First flow detection device 141; Water supply control valve 142; Flow stabilizing valve 14 3; Pressure reducing valve 144; Filter 145; Slurry conveying pump 15; First electromagnetic starter 16; Second electromagnetic starter 17; Liquid level detection device 18; Spraying unit 21; Nozzle 211; Base 2111; Liquid chamber 21111; Inlet 21111a; Outlet 21111b; Connecting lug 2112; Connecting joint 2113; Nozzle 2114; Slurry control valve 212; First valve port 2121; Second valve port 2122; Third valve port 2123; Three Pipe 213; Main control box 31; Sub-control box 32; Main slurry conveying pipe 41; Sub-slurry conveying pipe 42; Connecting assembly 50; First connector 51; First connecting part 511; First stop block 5111; First connecting post 5112; Fixing member 51121; First vibration-resistant and anti-loosening member 51122; First self-locking and anti-loosening member 51123; Second connecting part 512; First axis 511a; Second axis 512b; Second connector 52; Second stop block 521; Second connection Column 522; Second anti-vibration and anti-loosening component 523; Second self-locking and anti-loosening component 524; Hydraulic support 200; Base 201; Front scraper conveyor 202; Rear scraper conveyor 203; Top beam 204; Shield beam 205; Tail beam 206; Tail beam insert plate mechanism 207; Column 208; Front connecting rod 209; Rear connecting rod 210; Tail beam jack 2101; First pressure detection device 2102; Rear scraper conveyor return oil pipeline 2103; Mounting seat 2104; Coal mining machine 300. Detailed Implementation

[0035] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0036] This application provides a longwall top coal caving mining system 1000. Please refer to [link / reference]. Figures 1-4The longwall top coal caving mining system 1000 includes a coal mining machine 300 and multiple hydraulic supports 200. The hydraulic supports 200 are located between the coal mining face 1001 and the goaf 1002. The multiple hydraulic supports 200 are arranged sequentially along the extension direction of the coal mining face 1001. Each hydraulic support 200 includes a base 201, a front scraper conveyor 202 and a rear scraper conveyor 203. The front scraper conveyor 202 is located at the front of the base 201 and can push forward, while the rear scraper conveyor 203 is located at the rear of the base 201 and can pull towards the base 201.

[0037] It should be noted that when the strike longwall mining face extends along the dip direction and advances along the strike direction, the "extension direction of coal mining face 1001" refers to the dip direction of the mining face; when the dip longwall mining face extends along the strike direction and advances along the dip direction, the "extension direction of coal mining face 1001" refers to the strike direction of the mining face.

[0038] In addition, it should be noted that an intake air roadway and a return air roadway are arranged on both sides of the coal mining face 1001, and the extension direction of the coal mining face 1001 mentioned in this application refers to the direction from the intake air roadway to the return air roadway.

[0039] Please continue reading. Figures 1-4 The hydraulic support 200 may further include a top beam 204, a shield beam 205, a tail beam 206, a column 208, a front connecting rod 209, and a rear connecting rod 210. One end of the shield beam 205 is hinged to the rear end of the top beam 204, and the other end of the shield beam 205 is hinged to the tail beam 206. The rear scraper conveyor 203 is located at the rear of the base 201 and below the tail beam 206. The column 208 is hinged between the top beam 204 and the base 201. The front connecting rod 209 and the rear connecting rod 210 are both hinged between the base 201 and the shield beam 205, with the front connecting rod 209 located in front of the rear connecting rod 210. The hydraulic support 200 also includes a tail beam jack 2101, one end of which is hinged to the shield beam 205, and the other end of which is hinged to the tail beam 206. The function of the tail beam jack 2101 is to provide support for the tail beam 206 and drive the tail beam 206 to swing. The tail beam 206 has a sliding tail beam insert mechanism 207. The tail beam insert mechanism 207 extends to block the coal and gangue that collapses above the hydraulic support 200, and retracts to release coal, so that the coal and gangue that collapses above the hydraulic support 200 falls onto the rear scraper conveyor 203.

[0040] Specifically, the coal mining machine 300 operates at the set low-end coal cutting height, and the front scraper conveyor 202 transports the coal out of the working face. During the system's backfilling and pushing (moving the support and pushing the front scraper conveyor 202), the remaining coal above the coal cut by the coal mining machine 300 will be induced to collapse, and the broken coal blocks 1004 will fall onto the deployed tail beam 206 (see [reference]). Figure 1 Tail beam jack 2101 drives tail beam 206 to swing toward base 201 and tail beam insert mechanism 207 retracts into tail beam 206 (see [link]). Figure 2 When the coal discharge window is opened, the broken coal chunks 1004 above the hydraulic support 200 fall onto the rear scraper conveyor 203, which then transports the coal out of the working face.

[0041] When the content of gangue 1005 in the crushed coal gangue to be released above the hydraulic support 200 exceeds a certain limit, the tail beam 206 swings away from the base 201 and the tail beam insert mechanism 207 extends (see [reference]). Figure 3 That is, the coal discharge window is closed, thereby preventing the coal and gangue above the hydraulic support 200 from falling. After the coal discharge window is closed, the rear scraper conveyor 203 is pulled toward the hydraulic support 200 (see [link]). Figure 4 The production process of the 1001 coal mining face usually follows the cycle of coal cutting: 300 coal mining machine inclined cutting → coal cutting → frame shifting → pushing forward scraper conveyor 202 → top coal caving → pulling back scraper conveyor 203.

[0042] Understandably, please continue reading. Figure 4 When the rear scraper conveyor 203 is pulled toward the hydraulic support 200, the remaining coal chunks 1004 above the hydraulic support 200 will fall under gravity, thus forming "residual coal 1003" below the tail beam 206, which is the "residual coal 1003 after support" mentioned in this application. The fire prevention and extinguishing management of the residual coal 1003 after support is crucial for preventing fires in the goaf 1002. The longwall top coal caving mining system 1000 of this application also includes a fire prevention and extinguishing management system 100 for the residual coal after support of the hydraulic support 200 used in longwall top coal caving mining.

[0043] Please see Figures 5-7 and combined Figures 1-4 The fire prevention and extinguishing system 100 for residual coal after 200 hydraulic supports includes a slurry supply system 10 for supplying fire extinguishing slurry, a spraying system for spraying the fire extinguishing slurry toward the residual coal 1003, and a control device. The fire extinguishing slurry refers to a slurry formed by mixing fire extinguishing materials with a liquid (e.g., water). It should be noted that the fire extinguishing slurry used in the fire prevention and extinguishing system 100 for residual coal after 200 hydraulic supports in this application can be arbitrarily selected as needed. Optionally, the fire extinguishing material can be a water-based gel fire extinguishing material.

[0044] The spraying system includes multiple spraying units 21, each of which includes at least one nozzle 211 and a spraying control valve 212 for controlling the connection and disconnection between the nozzle 211 and the slurry supply system 10. That is, a spraying unit 21 may include one nozzle 211, or it may include two nozzles 211 (e.g., ...). Figure 7 (as shown in the diagram) or three nozzles 211, etc. A slurry control valve 212 is connected between the slurry supply system 10 and the nozzles 211 to control the on / off connection between them. When the slurry control valve 212 is open, the slurry supply system 10 and the nozzles 211 are connected, allowing the slurry supply system 10 to deliver slurry to the nozzles 211, which then spray it onto the surface of the residual coal 1003. When the slurry control valve 212 is closed, the slurry supply system 10 and the nozzles 211 are disconnected, and the nozzles 211 stop spraying. When the spraying unit 21 includes multiple nozzles 211, these nozzles 211 can be connected to the slurry supply system 10 via multi-port connecting pipes. For example, in... Figure 7 In the example shown, when the spraying unit 21 includes two nozzles 211, the two nozzles 211 can be connected to the slurry supply system 10 via a three-way pipe 213. Optionally, each spraying control valve 212 can control up to three nozzles 211 to avoid insufficient spraying pressure and flow rate due to an excessive number of controlled nozzles 211.

[0045] Multiple spraying units 21 are arranged sequentially and at intervals along the extension direction of the coal mining face 1001 so that the spraying range of the multiple spraying units 21 can cover all the residual coal 1003 behind the hydraulic supports 200 of the coal mining face 1001. Each spraying unit 21 corresponds to at least one hydraulic support 200, and the spraying range of each spraying unit 21 can cover the residual coal 1003 behind the corresponding hydraulic support 200.

[0046] In other words, each spraying unit 21 can correspond to only one hydraulic support 200, or it can correspond to two, three, or four hydraulic supports 200. When a spraying unit 21 corresponds to only one hydraulic support 200, the spraying range of the spraying unit can cover the residual coal 1003 behind that hydraulic support 200; when a spraying unit 21 corresponds to multiple hydraulic supports 200, for example... Figure 7 As shown, when the spraying unit 21 corresponds to four hydraulic supports 200, the spraying range of the spraying unit 21 can cover the residual coal 1003 behind the four hydraulic supports 200.

[0047] Additionally, it should be noted that the number of nozzles 211 and the corresponding number of hydraulic supports 200 in each of the multiple spraying units 21 can be the same or different, depending on the actual situation. For example, some spraying units 21 may each include two nozzles 211, while others may each include one nozzle 211; some spraying units 21 may each correspond to four hydraulic supports 200, while others may each correspond to two hydraulic supports 200.

[0048] At least one of the hydraulic supports 200 corresponding to the same spraying unit 21 is provided with a first pressure detection device 2102. The first pressure detection device 2102 is used to detect the oil pressure in the oil return line 2103 of the rear scraper conveyor of the hydraulic support 200 to determine whether the rear scraper conveyor 203 is being pulled toward the base 201 of the hydraulic support 200.

[0049] It should be noted that in longwall top coal caving mining, along the extension direction of the coal face 1001, multiple rear scraper conveyors 203 can be pulled toward the base 201 individually or in groups. That is, multiple rear scraper conveyors 203 can be pulled toward the base 201 individually or in groups, or multiple rear scraper conveyors 203 can be divided into multiple groups and pulled toward the base 201 in groups. Each group can include multiple (e.g., eight) rear scraper conveyors 203, and multiple (e.g., eight) rear scraper conveyors 203 in the same group are pulled toward the base 201 simultaneously.

[0050] The control device is electrically connected to the slurry supply system 10, the spraying control valve 212, and the first pressure detection device 2102. It controls the operation of the slurry supply system 10 and the opening and closing of multiple spraying control valves 212 based on the pressure signal detected by the first pressure detection device 2102. Furthermore, when the spraying control valve 212 is opened, it is closed only after the opening time has reached a preset duration. It should be noted that the "preset duration" mentioned here can be the shortest time required for the spraying unit 21 to completely cover the residual coal 1003 within its corresponding range.

[0051] Specifically, by analyzing the oil pressure signal in the return oil line 2103 of the rear scraper conveyor detected by the first pressure detection device 2102, it can be determined whether the rear scraper conveyor 203 is being pulled towards the base 201. When the rear scraper conveyor 203 is being pulled towards the base 201, the coal blocks 1004 above the hydraulic support 200 will fall and accumulate below the tail beam 206, forming residual coal 1003 below the tail beam 206. When the control device determines that the rear scraper conveyor 203 is being pulled towards the base 201, the control device can control the slurry supply system 10 to operate to provide fire extinguishing slurry to the spraying unit 21, and at the same time control the corresponding spraying control valve 212 to open so as to spray the fire extinguishing slurry onto the surface of the residual coal 1003 on the corresponding hydraulic support 200.

[0052] In addition, by controlling the spraying control valve 212 to open for a preset time and then closing it, it can be ensured that the coal residue 1003 behind the frame can be fully covered by the fire extinguishing slurry. This avoids the situation where the fire extinguishing slurry is not fully covered on the surface of the coal residue 1003 due to the short spraying time, which would result in an unsatisfactory fire prevention and extinguishing effect on the coal residue 1003 behind the frame.

[0053] It should be emphasized that the opening duration of the shotcrete control valve 212 in this application is not affected by the start and stop of the pulling action of the rear scraper conveyor 203 toward the base 201. Even if the pulling action of the rear scraper conveyor 203 toward the base 201 has stopped, the opening duration of the shotcrete control valve 212 has not reached the preset duration. The shotcrete control valve 212 will remain open until its opening duration reaches the preset duration, at which point the control device will control the shotcrete control valve 212 to close.

[0054] In addition, when the control device detects that the rear scraper conveyor 203 is pulled towards the hydraulic support 200 of the base 201, corresponding to multiple spraying units 21, in order to avoid the problem that the spraying distance of the spraying unit 21 is too short to reach the area of ​​the residual coal 1003 behind the frame due to insufficient slurry supply pressure of the slurry supply system 10, the control device can control multiple spraying units 21 to connect to the slurry supply system 10 in sequence. That is, control the spraying control valves 212 of multiple spraying units 21 to connect to the slurry supply system 10 in sequence. When the spraying control valve 212 of the next spraying unit 21 is connected to the slurry supply system 10, the spraying control valve 212 of the previous spraying unit 21 is disconnected from the slurry supply system 10. The opening time of each spraying control valve 212 must reach the preset time before it can be closed.

[0055] The control device of this application also has a recording function. It can continuously detect the number and position of the hydraulic supports 200 that the rear scraper conveyor 203 is pulled toward the base 201, and record this information. According to the sequence, it controls the spraying control valves 212 of the corresponding spraying units 21 to open sequentially for a preset time. Even if the action of the rear scraper conveyor 203 pulling toward the base 201 has stopped, the control device can still control the corresponding spraying control valves 212 to open sequentially according to the recorded information, and control each spraying unit 21 to spray for a preset time, thereby ensuring that the residual coal 1003 behind each hydraulic support 200 can be fully covered with fire extinguishing slurry.

[0056] Based on this, this application discloses a method for preventing and extinguishing fires in the residual coal 1003 after 200 hydraulic supports are used in longwall top coal caving mining. The method for preventing and extinguishing fires in the residual coal 1003 after 200 hydraulic supports includes:

[0057] The control device obtains the number and position of all hydraulic supports 200 whose rear scraper conveyors 203 are pulled towards the base 201 based on the pressure signals fed back by all the first pressure detection devices 2102. When it detects that a rear scraper conveyor 203 is being pulled towards the base 201, it starts the slurry supply system 10 to prepare fire extinguishing slurry. Based on the detected number and position of the hydraulic supports 200, the control device controls the spraying unit 21 corresponding to the detected hydraulic support 200 to switch on and off with the slurry supply system 10 according to a set mode. The set mode is as follows:

[0058] When there is one spraying unit 21 corresponding to the detected hydraulic support 200, the spraying unit 21 is connected to the slurry supply system 10 so that the spraying unit 21 can spray fire extinguishing slurry toward the coal residue 1003, and when the spraying time reaches the preset time, the spraying unit 21 is disconnected from the slurry supply system 10 to stop spraying.

[0059] When there are multiple spraying units 21 corresponding to the detected hydraulic support 200, the multiple spraying units 21 are controlled to connect sequentially to the slurry supply system 10 along the extension direction of the coal mining face 1001. When the next spraying unit 21 connects to the slurry supply system 10, the previous spraying unit 21 disconnects from the slurry supply system 10. The duration of each spraying unit 21 connecting to the slurry supply system 10 is a preset duration.

[0060] According to the embodiment of this application, the hydraulic support 200-frame residual coal fire prevention and extinguishing system 100 for longwall top coal caving mining uses a control device to control the operation of the slurry supply system 10 and the opening and closing of multiple slurry control valves 212 based on the pressure signal detected by the first pressure detection device 2102. Specifically, the residual coal fire prevention and extinguishing system 100 uses the pulling of the rear scraper conveyor 203 towards the base 201 as a trigger condition to initiate the automatic spraying program of the fire prevention and extinguishing slurry, thereby automating the fire prevention and extinguishing of the residual coal 1003 behind the hydraulic support 200. Using the pulling of the rear scraper conveyor 203 towards the base 201 as a trigger condition ensures that when spraying the fire prevention and extinguishing slurry, all the coal blocks 1004 above the hydraulic support 200 fall and accumulate below the tail beam 206 to form the residual coal 1003 behind the support, thus avoiding the problem of some coal blocks not falling into the slurry spraying range during the spraying of the fire prevention and extinguishing slurry. Furthermore, by ensuring that the spraying control valve 212 remains open for a preset duration before closing, it is guaranteed that the spraying unit 21 can fully spray the residual coal 1003 behind the frame, ensuring that the fire-fighting slurry can fully cover the residual coal 1003, resulting in thorough spraying and effective fire prevention and extinguishing. Moreover, the control device has a recording function, recording the position and number of hydraulic supports 200 in which the rear scraper conveyor 203 is pulled towards the base 201. Based on the recorded information, the control device sequentially opens the spraying control valves 212 of the corresponding spraying units 21 for a preset duration. This not only ensures the spraying pressure of each spraying unit 21 but also guarantees the spraying duration of each unit, ensuring that each spraying unit 21 can fully spray the residual coal 1003 behind the frame.

[0061] In one optional embodiment of this application, each spraying unit 21 corresponds to 1 to 4 hydraulic supports 200. That is, each spraying unit 21 can correspond to 1, 2, 3 or 4 hydraulic supports 200. When the spraying unit 21 corresponds to 1 hydraulic support 200, the spraying range of the spraying unit 21 can cover the residual coal 1003 behind the 1 hydraulic support 200; when the spraying unit 21 corresponds to 2 hydraulic supports 200, the spraying range of the spraying unit 21 can cover the residual coal 1003 behind the 2 hydraulic supports 200, and so on.

[0062] Please see Figure 7 and combined Figures 1-4When the hydraulic supports 200 corresponding to the same spraying unit 21 include four hydraulic supports 200 arranged sequentially along the extension direction of the coal mining face 1001, the spraying unit 21 includes two nozzles 211. One nozzle 211 is adapted to be installed on the front connecting rod 209 of the first hydraulic support 200 among the four hydraulic supports 200, and the other nozzle 211 is adapted to be installed on the front connecting rod 209 of the third hydraulic support 200 among the four hydraulic supports 200. The two nozzles 211 of the spraying unit 21 can be connected to the slurry control valve 212 through a three-way pipe 213. In this way, the cost can be reduced while ensuring sufficient slurry spraying of the residual coal 1003. Of course, this application is not limited to this, and each hydraulic support 200 can also be provided with a nozzle 211, so that the spraying is more complete.

[0063] It should be noted that the location of the nozzle 211 can be selected according to actual needs. The nozzle 211 can be set at, for example... Figures 1-4 The nozzle 211 can also be mounted on the shield beam 205 or the rear link 210 of the hydraulic support 200, etc.

[0064] Furthermore, intake airway and return airway are respectively arranged on both sides of the coal mining face 1001. The slurry supply system 10 can be located in the intake airway and can be located in the electrical equipment train in the intake airway. As the coal mining face 1001 moves forward, the electrical equipment train also moves forward. The last slurry control valve 212 of the plurality of slurry control valves 212 along the extension direction of the coal mining face 1001 includes a first valve port 2121 and a second valve port 2122 that can be switched on and off with each other. The remaining slurry control valves 212 all include a first valve port 2121, a second valve port 2122 and a third valve port 2123, and the first valve port 2121 can be selectively connected to one of the second valve port 2122 and the third valve port 2123. In other words, the first valve port 2121 can be connected to the second valve port 2122, and the first valve port 2121 can also be connected to the third valve port 2123. When the first valve port 2121 is connected to the second valve port 2122, the first valve port 2121 is disconnected from the third valve port 2123; when the first valve port 2121 is connected to the third valve port 2123, the first valve port 2121 is disconnected from the second valve port 2122. Optionally, the last shotcrete control valve 212 in the extension direction along the coal mining face 1001 can be a two-way electric ball valve, and the remaining shotcrete control valves 212 can all be three-way electric ball valves.

[0065] The fire prevention and extinguishing system also includes a slurry delivery main pipe 41. One end of the slurry delivery main pipe 41 is connected to the slurry supply system 10. The first valve port 2121 of the first slurry control valve 212 along the extension direction of the coal mining face 1001 is connected to the other end of the slurry delivery main pipe 41. The second valve port 2122 of each slurry control valve 212 is connected to its corresponding nozzle 211. The third valve port 2123 of the first slurry control valve 212 in the extension direction of the coal mining face 1001 is connected to the first valve port 2121 of the second slurry control valve 212 through the slurry delivery sub-pipe 42. In this way, by controlling the opening and closing of the multiple slurry control valves 212, the slurry delivered by the slurry supply system 10 will not flow into the excess slurry delivery sub-pipe 42, thereby avoiding the slurry from accumulating and solidifying in the excess slurry delivery sub-pipe 42 for a long time and clogging the pipeline.

[0066] Please see Figures 5-6 The slurry supply system 10 includes: a storage silo 11, a mixing silo 12, a material conveying device 13, a water supply assembly 14, and a slurry conveying pump 15. The storage silo 11 defines a storage chamber for storing materials (fire extinguishing materials), and the mixing silo 12 defines a mixing chamber. The mixing silo 12 has a water inlet 121, a feeding port 122, and a slurry outlet 123 that communicate with the mixing chamber. The water inlet 121 is used to add water into the mixing chamber, and the feeding port 122 is used to add fire extinguishing materials into the mixing chamber. The water added to the mixing chamber and the fire extinguishing materials are mixed to form a fire extinguishing slurry, which is then discharged through the slurry outlet 123 to supply fire extinguishing slurry to the spraying unit 21.

[0067] Material conveying device 13 is connected between storage silo 11 and feed port 122 to quantitatively convey the material stored in storage silo 11 to mixing chamber. Water supply component 14 is connected between water source and water inlet 121 to quantitatively supply water to mixing chamber. The inlet end of slurry conveying pump 15 is connected to slurry outlet 123, and the outlet end of slurry conveying pump 15 is connected to one end of slurry conveying main pipe 41. Material conveying device 13, water supply component 14, and slurry conveying pump 15 are all electrically connected to control device. Control device controls material conveying device 13 to quantitatively convey fire extinguishing material into mixing chamber and controls water supply component 14 to quantitatively supply water into mixing chamber. Fire extinguishing material and water mix in mixing chamber to form fire extinguishing slurry. By controlling slurry conveying pump 15, the slurry formed in mixing chamber can be conveyed to spraying system, thereby realizing the supply of fire extinguishing slurry.

[0068] Optionally, when it is necessary to supply fire extinguishing slurry to the spraying system, the water supply component 14 can be controlled to add water to the mixing chamber first, and the material conveying device 13 can be stopped. At this time, water is supplied to the spraying system for a certain period of time to determine whether there is a pipeline blockage in the slurry supply system 10 and the spraying system. After determining that there is no pipeline blockage, the material conveying device 13 is then controlled to convey the material into the mixing chamber.

[0069] Please see Figures 5-6 The material conveying device 13 can be a screw conveyor, which transports the material in the storage silo 11 to the mixing chamber. Of course, this application is not limited to this; the material conveying device 13 can be arbitrarily selected as needed, for example, it can also be an air amplifier. The material conveying device 13 can be electrically connected to the control device via the first electromagnetic starter 16, thus ensuring the safety of mine production operations.

[0070] Optionally, the slurry delivery pump 15 can be a three-cylinder plunger pump. The slurry delivery pump 15 can be electrically connected to the control device through the second electromagnetic starter 17, which can ensure the safety of mine production operations.

[0071] Please continue reading. Figures 5-6 The mixing chamber 12 is equipped with a liquid level detection device 18 to detect the liquid level in the mixing chamber. Optionally, the liquid level detection device 18 can be a float level switch. The liquid level detection device 18 is electrically connected to the control device. When the liquid level value detected by the liquid level detection device 18 is greater than or equal to a preset liquid level threshold, it indicates that the liquid level in the mixing chamber is abnormal and there is a risk of overflow. The control device controls the water supply component 14 to stop water supply and controls the material conveying device 13 to stop material conveying. When the liquid level value detected by the liquid level detection device 18 is less than the preset liquid level threshold within a preset observation period, it indicates that the liquid level in the mixing chamber has returned to normal and the risk of overflow has been eliminated. The control device controls the water supply component 14 to start water supply and controls the material conveying device 13 to start material conveying. By setting up the liquid level detection device 18, when the liquid level in the mixing chamber is abnormal, the continued delivery of materials and water into the mixing chamber can be stopped in time to avoid the slurry overflowing from the mixing chamber.

[0072] Please continue reading. Figures 5-6The water supply assembly 14 may include a first flow detection device 141 (flow sensor) and a water supply control valve 142. The water supply control valve 142 is connected between a water source (e.g., an underground water supply network 1006) and an inlet 121 to control the flow between the water source and the inlet 121. The first flow detection device 141 may be located between the water supply control valve 142 and the inlet 121 to detect the water flow rate into the mixing chamber, thereby ensuring a quantitative water supply into the mixing chamber and thus ensuring the water-material ratio in the mixing chamber. Optionally, the water supply control valve 142 may be an electric ball valve. Both the water supply control valve 142 and the first flow detection device 141 are electrically connected to a control device. The first flow detection device 141 can transmit the detected flow signal to the control device, and the control device can control the opening and closing of the water supply control valve 142 based on the received flow signal, etc. Optionally, please continue reading. Figures 5-6 The water supply assembly 14 may further include a flow stabilizing valve 143 and a pressure reducing valve 144, which are connected in series between the water supply control valve 142 and the first flow detection device 141. By setting the flow stabilizing valve 143 and the pressure reducing valve 144, not only can the water supply assembly 14 be ensured to supply water smoothly into the mixing chamber, but the impact of the water flow on the first flow detection device 141 can also be reduced, thus protecting the first flow detection device 141.

[0073] Please continue reading. Figures 5-6 The water supply assembly 14 may also include a filter 145, which is connected between the water source and the water supply control valve 142. The filter 145 first filters out impurities in the water before it flows sequentially through the water supply control valve 142, the flow stabilizing valve 143, the pressure reducing valve 144, and the first flow detection device 141, and finally enters the mixing chamber. By setting the filter 145, impurities in the water can be prevented from entering the mixing chamber and causing impurities in the fire extinguishing slurry, and impurities in the water can also be prevented from damaging electrical components.

[0074] Furthermore, when the water supply flow rate detected by the first flow detection device 141 is less than the first preset flow rate threshold, the control device controls the material conveying device 13 to stop material conveying and controls the slurry conveying pump 15 to stop slurry conveying. The fact that the water supply flow rate detected by the first flow detection device 141 is less than the first preset flow rate threshold indicates that the water supply to the mixing chamber is less than the required water supply. Therefore, the control device stops the material conveying device 13 and the slurry conveying pump 15 to stop slurry conveying to avoid material waste.

[0075] Optionally, please refer to Figures 5-6A second flow detection device (not shown in the figure) for detecting the flow rate of slurry is provided between the outlet end of the slurry conveying pump 15 and one end of the slurry conveying main pipe 41. The second flow detection device is electrically connected to the control device. When the slurry conveying flow rate detected by the second flow detection device is less than the second preset flow threshold, the control device controls the material conveying device 13 to stop material conveying and controls the water supply component 14 to stop water supply. When the slurry delivery flow rate detected by the second flow detection device is less than the second preset flow rate threshold, the following risks are indicated: (1) The slurry delivery pump 15 malfunctions and cannot pump slurry normally. In other words, the slurry formed in the mixing chamber may not be discharged in time through the slurry outlet 123. At this time, the material delivery device 13 is controlled to stop material delivery and the water supply component 14 is controlled to stop water supply to avoid the slurry overflowing in the mixing chamber; (2) The slurry delivery pipeline (slurry delivery main pipe 41, slurry delivery sub-pipe 42) or the spraying system is blocked. At this time, the material delivery device 13 is controlled to stop material delivery and the water supply component 14 is controlled to stop water supply to avoid the slurry delivery pump 15 continuously pumping slurry to the slurry delivery pipeline and the spraying system, which may lead to the risk of pipeline rupture.

[0076] Optionally, please refer to Figures 5-6 The mixing silo 12 also has an overflow port (not shown) connected to the mixing chamber. The fire prevention and extinguishing system also includes a second pressure detection device (not shown), an overflow pipe (not shown), and an overflow valve (not shown). The second pressure detection device is used to detect the pressure at the outlet end of the slurry conveying pump 15. One end of the overflow pipe is connected to the outlet end of the slurry conveying pump 15, and the other end of the overflow pipe is connected to the overflow port. The overflow valve is located between the other end of the overflow pipe and the overflow port. Both the second pressure detection device and the overflow valve are electrically connected to the control device. When the slurry conveying pressure value detected by the second pressure detection device is greater than or equal to the preset pressure threshold, the control device controls the overflow valve to open.

[0077] When the slurry delivery pressure detected by the second pressure detection device is greater than or equal to the preset pressure threshold, it indicates that there is a blockage in the slurry delivery pipeline (slurry delivery main pipe 41, slurry delivery sub-pipe 42) or the spraying system. At this time, by controlling the overflow valve to open, the slurry in the pipeline can be sent back to the mixing chamber, which can not only relieve the pressure in the pipeline, but also avoid slurry waste.

[0078] In some embodiments, the fire prevention and extinguishing system may omit the overflow port, overflow valve, and overflow pipe described in the above embodiments, and instead only include the second pressure detection device described in the above embodiments. The second pressure detection device is electrically connected to the control device. When the slurry delivery pressure value detected by the second pressure detection device is greater than or equal to a preset pressure threshold, the control device may also control the material delivery device 13 to stop material delivery, control the water supply component 14 to stop water supply, and control the slurry delivery pump 15 to shut down. This avoids the risk of pipeline rupture caused by the slurry delivery pump 15 continuously pumping slurry into the slurry delivery pipeline and spraying system.

[0079] In some embodiments, the fire prevention and control system may be equipped with a second flow detection device and a second pressure detection device as described in the above embodiments. The second flow detection device and the second pressure detection device can play a dual protection role, so as to avoid the system being unable to respond in time when the pipeline is blocked due to the failure of one of the second flow detection device and the second pressure detection device.

[0080] Please see Figures 5-7 The control device may include a main control box 31 and multiple sub-control boxes 32. The multiple sub-control boxes 32 are all electrically connected to the main control box 31. The shotcrete control valve 212 and the first pressure detection device 2102 are all connected to the sub-control box 32. A sub-control box 32 can be electrically connected to a maximum of four shotcrete control valves 212 and four first pressure detection devices 2102 to avoid the phenomenon of insufficient load-bearing capacity of the sub-control box 32.

[0081] Please see Figures 1-4 as well as Figures 8-13 As shown, the nozzle 211 is connected to the front link 209 of the hydraulic support 200 via a connecting assembly 50. The connecting assembly 50 includes a first connector 51, which has a first connecting portion 511 and a second connecting portion 512 connected to each other. The first connecting portion 511 is rotatably connected to the nozzle 211 about a first axis 511a, and the second connecting portion 512 is rotatably connected to the front link 209 about a second axis 512b. The first axis 511a and the second axis 512b are perpendicular to each other. By rotatably connecting the first connecting portion 511 to the nozzle 211 about the first axis 511a, the nozzle 211 can rotate relative to the first connector 51 about the first axis 511a; by rotatably connecting the second connecting portion 512 to the front link 209 about the second axis 512b, the first connecting portion 51 can rotate relative to the front link 209 about the second axis 512b. This allows the nozzle 211 to be connected to the front link 209 of the hydraulic support 200 via the connecting assembly 50. By rotating the nozzle 211 relative to the first connecting member 51 about the first axis 511a and by rotating the first connecting member 51 relative to the front link 209 about the second axis 512b, omnidirectional adjustment of the nozzle 211 can be achieved (e.g., ...). Figures 11-13 This allows the nozzle 211 to be aligned with the area to be sprayed according to the needs of the site environment, avoiding the need to disassemble the nozzle 211 repeatedly.

[0082] Please see Figures 9-10 The first connecting portion 511 includes a first stop block 5111 and a first connecting post 5112. The first connecting post 5112 extends along the extension direction of the first axis 511a. One end of the first connecting post 5112 is connected to the first stop block 5111. A fixing member 51121 is connected to the first connecting post 5112. The nozzle 211 is rotatably fitted onto the first connecting post 5112 and sandwiched between the first stop block 5111 and the fixing member 51121. By rotating the nozzle 211 relative to the first connecting post 5112, the nozzle 211 can rotate relative to the first connecting member 51 about the first axis 511a. By clamping the nozzle 211 between the first stop block 5111 and the fixing member 51121, the nozzle 211 can be positioned on the first connecting post 5112. That is, after the nozzle 2114 of the nozzle 211 is rotated and adjusted relative to the first connecting post 5112, the fixing member 51121 is tightened to clamp the nozzle 211 between the first stop block 5111 and the fixing member 51121, thus fixing the connection position between the nozzle 211 and the first connecting member 51. Optionally, the first connecting post 5112 and the fixing member 51121 are threaded together, and the fixing member 51121 can be a nut. By using a threaded connection between the first connecting post 5112 and the fixing member 51121, the connection between the first connecting post 5112 and the fixing member 51121 is stable and not prone to loosening, while the fixing member 51121 is easy to install and remove.

[0083] Please continue reading. Figures 9-10 A first anti-vibration and anti-loosening component 51122 is provided between the fixing component 51121 and the nozzle 211, and a first self-locking anti-loosening component 51123 is provided between the first stop block 5111 and the nozzle 211. Optionally, the first anti-vibration and anti-loosening component 51122 can be a spring washer, and the first self-locking anti-loosening component 51123 can be a double-layered self-locking anti-loosening washer. This can prevent the nozzle 211 from becoming loose after its position is adjusted relative to the first connecting component 51, which would cause the orientation of the nozzle 2114 of the nozzle 211 to change and prevent it from being accurately aimed at the area to be sprayed.

[0084] In some examples, only the fastener 51121 and the nozzle 211 are provided with a first anti-vibration and anti-loosening component 51122, and no first self-locking anti-loosening component 51123 is provided between the first stop block 5111 and the nozzle 211; in other examples, no first anti-vibration and anti-loosening component 51122 is provided between the fastener 51121 and the nozzle 211, and only the first self-locking anti-loosening component 51123 is provided between the first stop block 5111 and the nozzle 211.

[0085] Please continue reading. Figures 9-10 The nozzle 211 includes a base 2111 and a connecting lug 2112. The base 2111 defines a liquid-containing chamber 21111. The base 2111 has an inlet 21111a and an outlet 21111b communicating with the liquid-containing chamber 21111. The inlet 21111a is connected to the outlet end of the shotcrete control valve 212 via a slurry delivery pipe. When the shotcrete control valve 212 is open, slurry can enter the liquid-containing chamber 21111 through the inlet 21111a. The inlet 21111a can be connected to a connecting connector 2113, which connects to the slurry delivery pipe. The outlet 21111b is connected to a nozzle 2114. After entering the liquid-containing chamber 21111, the slurry is sprayed through the nozzle 2114 to the desired spraying area. Optionally, both the connector 2113 and the nozzle 2114 are threadedly connected to the nozzle 211.

[0086] The connecting ear 2112 is connected to the side of the base 2111 opposite to the outlet 21111b. The connecting ear 2112 is rotatably fitted onto the first connecting post 5112 and sandwiched between the first stop block 5111 and the fixing member 51121. That is, the nozzle 211 is connected and fixed to the first connecting member 51 through the connecting ear 2112, which is convenient. At the same time, by connecting the connecting ear 2112 to the side of the base 2111 opposite to the outlet 2111b, the orientation adjustment of the nozzle 2114 is made more convenient.

[0087] Please continue reading. Figures 9-10 The hydraulic support 200 has a connection hole on its front connecting rod 209. The connecting assembly 50 also includes a second connecting member 52, which includes a second stop block 521 and a second connecting post 522. The second connecting post 522 extends along the extension direction of the second axis 512b. One end of the second connecting post 522 is connected to the second stop block 521, and the other end is connected to the connection hole. The second connecting portion 512 is rotatably fitted onto the second connecting post 522 and clamped between the second stop block 521 and the front connecting rod 209. By rotating the second connecting portion 512 of the first connecting member 51 relative to the second connecting post 522, the first connecting member 51 can rotate relative to the front connecting rod 209 relative to the second axis 512b. By clamping the second connecting portion 512 between the second stop block 521 and the front connecting rod 209, the first connecting member 51 can be positioned on the second connecting post 522.

[0088] Optionally, the second connecting post 522 is threaded into the connecting hole, thereby ensuring a stable connection between the second connecting post 522 and the front connecting rod 209, preventing loosening, and facilitating disassembly and assembly. The second connecting member 52 can be a bolt, the second stop block 521 can be the nut portion of the bolt, and the second connecting post 522 can be the threaded portion of the bolt.

[0089] Please see Figure 9 A second anti-vibration and anti-loosening component 523 is provided between the second stop block 521 and the second connecting part 512, and a second self-locking anti-loosening component 524 is provided between the second connecting part 512 and the front connecting rod 209. Optionally, the second anti-vibration and anti-loosening component 523 can be a spring washer, and the second self-locking anti-loosening component 524 can be a double-layered self-locking anti-loosening washer. This can prevent the first connecting part 51 from becoming loose after its position is adjusted relative to the front connecting rod 209, which would cause the orientation of the nozzle 2114 of the spray head 211 to change and fail to accurately aim at the area to be sprayed. In some examples, the second anti-vibration and anti-loosening component 523 is provided only between the second stop block 521 and the second connecting part 512, and the second self-locking anti-loosening component 524 is not provided between the second connecting part 512 and the front connecting rod 209; in other examples, the second anti-vibration and anti-loosening component 523 is not provided between the second stop block 521 and the second connecting part 512, and the second self-locking anti-loosening component 524 is provided only between the second connecting part 512 and the front connecting rod 209.

[0090] Optionally, please refer to Figures 8-9 The front connecting rod 209 is provided with a mounting base 2104, and the connecting hole is located on the mounting base 2104. The second connecting piece 52 is connected and fixed on the mounting base 2104.

[0091] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0092] In the description of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0093] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0094] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A fire prevention and extinguishing system for residual coal after hydraulic support erection in longwall top coal caving mining, characterized in that, include: A slurry supply system for supplying fire extinguishing slurry; A spraying system for spraying fire extinguishing slurry toward the residual coal, the spraying system comprising multiple spraying units, each spraying unit comprising at least one nozzle and a spraying control valve for controlling the connection and disconnection between the nozzle and the slurry supply system, the multiple spraying units being arranged sequentially at intervals along the extension direction of the coal mining face so that the spraying range of the multiple spraying units can cover all the residual coal behind the hydraulic supports of the coal mining face, each spraying unit corresponding to at least one hydraulic support, and the spraying range of each spraying unit being able to cover the residual coal behind the hydraulic support corresponding to it, at least one of the hydraulic supports corresponding to the same spraying unit being provided with a first pressure detection device, the first pressure detection device being used to detect the oil pressure in the return oil pipeline of the rear scraper conveyor of the hydraulic support to determine whether the rear scraper conveyor is being pulled toward the base of the hydraulic support; The control device is electrically connected to the slurry supply system, the spraying control valve, and the first pressure detection device. It controls the operation of the slurry supply system and the opening and closing of multiple spraying control valves based on the pressure signal detected by the first pressure detection device. When controlling the spraying control valve to open, it closes the valve after the opening time reaches a preset duration. The control device obtains the number and position of the hydraulic supports whose rear scraper conveyors are being pulled towards the base based on the pressure signals fed back by all the first pressure detection devices. When a rear scraper conveyor is detected being pulled towards the base, the control device starts the slurry supply system to prepare fire-extinguishing slurry. Based on the detected number and position of the hydraulic supports, the control device controls the spraying unit corresponding to the detected hydraulic support to switch on and off with the slurry supply system according to a set mode.

2. The fire prevention and extinguishing system for residual coal after hydraulic support erection in longwall top coal caving mining according to claim 1, characterized in that, When the hydraulic supports corresponding to the same spraying unit include four hydraulic supports arranged sequentially along the extension direction of the coal mining face, the spraying unit includes two nozzles, one nozzle being adapted to be installed on the front connecting rod of the first hydraulic support among the four hydraulic supports, and the other nozzle being adapted to be installed on the front connecting rod of the third hydraulic support among the four hydraulic supports.

3. The fire prevention and extinguishing system for residual coal after hydraulic support erection in longwall top coal caving mining according to claim 1, characterized in that, The coal mining face has intake and return air roadways arranged on both sides. The slurry supply system is located in the intake air roadway. The last slurry control valve among the plurality of slurry control valves along the extension direction of the coal mining face includes a first and a second valve port that can be switched on and off. The remaining slurry control valves each include a first, a second, and a third valve port, and the first valve port can be selectively connected to one of the second and third valve ports. The fire prevention and extinguishing system further includes: A slurry conveying main pipe is provided, one end of which is connected to the slurry supply system. The first valve port of the first slurry control valve in the extension direction of the coal mining face is connected to the other end of the slurry conveying main pipe. The second valve port of each slurry control valve is connected to the corresponding nozzle. The third valve port of the first slurry control valve in the extension direction of the coal mining face is connected to the first valve port of the second slurry control valve through a slurry conveying sub-pipe.

4. The fire prevention and extinguishing system for residual coal after hydraulic support erection in longwall top coal caving mining according to claim 3, characterized in that, The slurry supply system includes: A storage bin, wherein a storage cavity is defined within the storage bin for storing materials; A mixing bin, wherein a mixing chamber is defined within the mixing bin, and the mixing bin has a water inlet, a feed inlet, and a slurry outlet communicating with the mixing chamber; A material conveying device is connected between the storage silo and the feeding port to quantitatively convey the material stored in the storage silo to the mixing chamber; A water supply assembly is connected between a water source and the water inlet to supply a metered amount of water into the mixing chamber; The slurry conveying pump has its inlet end connected to the slurry outlet and its outlet end connected to one end of the slurry conveying main pipe. The material conveying device, the water supply component, and the slurry conveying pump are all electrically connected to the control device.

5. The fire prevention and extinguishing system for residual coal after hydraulic support erection in longwall top coal caving mining according to claim 4, characterized in that, The mixing chamber is equipped with a liquid level detection device for detecting the liquid level inside the mixing chamber. The liquid level detection device is electrically connected to the control device. When the liquid level detected by the liquid level detection device is greater than or equal to a preset liquid level threshold, the control device controls the water supply component to stop supplying water and controls the material conveying device to stop conveying materials. If the liquid level detected by the liquid level detection device is less than the preset liquid level threshold within the preset observation period, the control device controls the water supply component to start water supply and controls the material conveying device to start material conveying.

6. The fire prevention and extinguishing system for residual coal after hydraulic support erection in longwall top coal caving mining according to claim 4, characterized in that, The water supply assembly includes a first flow detection device for detecting the water supply flow rate. The first flow detection device is electrically connected to the control device. When the water supply flow rate detected by the first flow detection device is less than a first preset flow rate threshold, the control device controls the material conveying device to stop material conveying and controls the slurry conveying pump to stop slurry conveying.

7. The fire prevention and extinguishing system for residual coal after hydraulic support erection in longwall top coal caving mining according to claim 4, characterized in that, A second flow detection device for detecting the slurry conveying flow rate is provided between the outlet end of the slurry conveying pump and one end of the slurry conveying main pipe. The second flow detection device is electrically connected to the control device. When the slurry conveying flow rate detected by the second flow detection device is less than a second preset flow rate threshold, the control device controls the material conveying device to stop material conveying and controls the water supply component to stop water supply.

8. The fire prevention and extinguishing system for residual coal after hydraulic support erection in longwall top coal caving mining according to any one of claims 4-7, characterized in that, The mixing silo also has an overflow port communicating with the mixing chamber, and the fire prevention and extinguishing system further includes: A second pressure detection device is used to detect the pressure at the outlet end of the slurry conveying pump; An overflow pipe, one end of which is connected to the outlet end of the slurry conveying pump, and the other end of which is connected to the overflow port; An overflow valve is provided between the other end of the overflow pipe and the overflow port. The second pressure detection device and the overflow valve are both electrically connected to the control device. When the slurry conveying pressure value detected by the second pressure detection device is greater than or equal to a preset pressure threshold, the control device controls the overflow valve to open.

9. A longwall top coal caving mining system, characterized in that, include: Multiple hydraulic supports are arranged sequentially along the extension direction of the coal mining face. Each hydraulic support includes a base and a rear scraper conveyor. The rear scraper conveyor is located at the rear of the base and can be pulled toward the base. The fire prevention and extinguishing system for residual coal behind the hydraulic support frame according to any one of claims 1-8.

10. A method for preventing and extinguishing fires caused by residual coal after the hydraulic support is erected in longwall top coal caving mining, characterized in that, The method for preventing and extinguishing fires caused by residual coal behind hydraulic support frames employs the fire prevention and extinguishing system for residual coal behind hydraulic support frames according to any one of claims 1-8. The method includes: The setting mode is as follows: When there is one spraying unit corresponding to the detected hydraulic support, the spraying unit is controlled to connect with the slurry supply system so that the spraying unit can spray fire extinguishing slurry towards the coal residue. When the spraying time reaches the preset time, the spraying unit is controlled to disconnect from the slurry supply system to stop spraying. When there are multiple spraying units corresponding to the detected hydraulic support, the multiple spraying units are controlled to connect sequentially to the slurry supply system along the extension direction of the coal mining face. When the next spraying unit connects to the slurry supply system, the previous spraying unit disconnects from the slurry supply system. The duration for which each spraying unit connects to the slurry supply system is the preset duration.

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