Equipment and method for inhibiting early oxidation of residual coal in goaf

Abstract

The present invention discloses an equipment and method for inhibiting early oxidation of residual coal in goaf. The equipment and method comprises the following steps: pre-arranging a conveying pipeline in the goaf, and providing nozzles at intervals between the pipelines. A fusible alloy and a temperature sensor are provided at the nozzles. When oxidation of residual coal occurs in the goaf, the temperature sensor detects a rise in the temperature of the space, and reduces air leakage into the goaf to inhibit oxidation of the coal body. If the coal body continues to oxidize, the fusible alloy melts due to the increase in regional temperature, and slurry is injected from the nozzles to the high-temperature region to control early oxidation. After grouting, the control situation can be detected in real time by collecting and analyzing gas data. Compared with traditional coal spontaneous combustion fire prevention and extinguishing technology, the present invention controls air leakage and subsequent fixed-point grouting in the oxidation stage before coal spontaneous combustion occurs, thereby preventing continuous oxidation of the coal body from causing combustion. The high-temperature position can be accurately determined and controlled in time, thereby preventing large-scale spontaneous combustion of residual coal, which would cause waste of resources and environmental pollution.

Description

Technical Field

[0001] The invention relates to equipment and a method for inhibiting early oxidation of residual coal in a goaf, belonging to the technical field of coal mine fire prevention and extinguishing. Background Art

[0002] Mine fire is one of the major natural disasters in coal mines, and spontaneous combustion of coal is the main cause of mine fire. The development process of spontaneous combustion of coal can usually be divided into three periods: the preparation period (i.e., temperature <70°C), when the groups in the coal come into contact with air to undergo a slow oxidation reaction; the self-heating period (i.e., temperature 70-350°C), during which the coal body accelerates oxidation and produces a large amount of harmful gases; the combustion period (i.e., temperature >350°C), during which the coal oxidation rate rises sharply to produce a large amount of heat. The goaf has a large amount of residual coal, which provides a good heat storage environment for coal oxidation and self-heating. At the same time, during the preparation period of the spontaneous combustion of coal, due to the slow oxidation without obvious phenomena, and the goaf is relatively hidden, the oxidation of residual coal cannot be discovered in time, thus losing the best stage for fire control.

[0003] Normally, when coal spontaneously ignites and reaches the self-heating stage, the regional temperature rises and produces a large amount of harmful gases. The spontaneous combustion of coal in the goaf can only be discovered by collecting and analyzing the gas in the closed or drilled areas. However, at this time, the process of coal ignition has reached the second stage. The coal body has been accelerated to oxidize, and the temperature rises rapidly, which can easily cause large-scale spontaneous combustion. In addition, since the gas produced by spontaneous combustion can flow with the air, although spontaneous combustion can be discovered, the ignition location cannot be accurately determined, and it is impossible to accurately control and suppress spontaneous combustion, resulting in rapid self-heating of the coal to the combustion stage to form a fire. When the coal body is controlled during the self-heating and combustion stages, it not only increases the difficulty of control, but also causes waste of resources and environmental pollution. For this reason, how to discover and determine the specific location of coal in the preparation period of the spontaneous combustion stage, and then take fire prevention and extinguishing measures at the location, so as to suppress the spontaneous combustion of coal in the early oxidation stage of the coal, is the research direction of this industry. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention provides an equipment and method for suppressing the early oxidation of residual coal in goaf, which can be discovered and the specific location can be determined in the preparation period of the coal in the spontaneous combustion stage, and then fire prevention and extinguishing measures can be taken at that location, thereby suppressing the spontaneous combustion of the residual coal in the early oxidation stage of the residual coal.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: an equipment for inhibiting early oxidation of residual coal in goaf, including a grouting system, an automatic grouting system, a temperature monitoring system and a gas detection system;

[0006] The grouting system includes a slurry barrel, a pneumatic mixer, a screw pump and a slurry delivery pipeline. The pneumatic mixer is installed in the slurry barrel. The slurry barrel is connected to the inlet of the screw pump through a pipeline. The outlet of the screw pump is connected to one end of the slurry delivery pipeline. The slurry delivery pipeline is equipped with a pressure gauge and a slurry delivery valve.

[0007] The automatic shotcrete system comprises a main pipeline and a plurality of branch pipelines, one end of the plurality of branch pipelines is blocked and the other end is connected to one end of the main pipeline, each branch pipeline is equipped with a plurality of nozzles, the nozzles are composed of a nozzle pipe and a plurality of nozzles, one end of the nozzle pipe is blocked and the other end is connected to the branch pipeline, a plurality of nozzles are distributed on the nozzle pipe, a fusible plug is arranged inside each nozzle, and the nozzle is sealed by a fusible cover; wherein the fusible cover is used to prevent the top plate debris from falling and blocking the nozzle, and the fusible plug is used to prevent the slurry inside the nozzle pipe from spraying out from the nozzle; the other end of the main pipeline is connected to the other end of the slurry delivery pipeline through a connecting pipe;

[0008] The temperature monitoring system includes a plurality of wireless temperature sensors, a data receiver and a data processor, wherein the data receiver and the data processor are connected via a data transmission line, each wireless temperature sensor is respectively arranged on a nozzle, and is used to detect the real-time temperature value of the nozzle position, and send the detected temperature value via a wireless signal; the data receiver is used to receive the temperature value sent by each wireless temperature sensor, and feed the data back to the data processor; the data processor analyzes and processes the real-time temperature value, and sends out an early warning signal;

[0009] The gas detection system includes a gas analyzer and a gas collector, which are connected by a rubber tube. When gas detection is required, the other end of the main pipeline is first disconnected from the other end of the slurry delivery pipeline, and then the other end of the main pipeline is connected to the gas collector through a connecting tube. The gas collector collects gas data through each nozzle of the automatic spraying system, and the gas analyzer analyzes and processes the gas data collected by the gas collector.

[0010] Furthermore, the fusible cover is made of an indium-bismuth alloy, and its melting temperature is 57°C; the fusible plug is made of a bismuth-tin alloy, and its melting temperature is 70°C.

[0011] Furthermore, the main pipeline and the multiple branch pipelines are all nylon tubes that can withstand a temperature of 260°C.

[0012] Furthermore, each nozzle has three nozzles, which are staggeredly distributed on the outer circumference of the nozzle pipe, and the directions of the nozzles are 45° with the axial direction of the nozzle pipe.

[0013] A working method of equipment for inhibiting early oxidation of residual coal in goaf, the specific steps are:

[0014] A. Install multiple anchor rods at the top of the coal mine goaf area to be inspected, evenly lay the branch pipes of the automatic shotcrete system in the natural goaf area, and fix the branch pipes with the anchor rods through the lower pipe clamp, upper pipe clamp and screws. Then, determine the raw material ratio of the fire extinguishing slurry according to the actual situation of the coal mine goaf area, put the required raw materials into the slurry making barrel, and start the pneumatic mixer to prepare the fire extinguishing slurry; store the temperature alarm threshold of 40°C in the data processor, thereby completing the equipment preparation;

[0015] B. When starting work, each wireless temperature sensor monitors the temperature value of the location in real time and feeds it back to the data processor through the data receiver. The data processor compares the real-time temperature value with the temperature alarm threshold. If the real-time temperature value exceeds 40°C, the data processor issues a temperature warning. At this time, the staff adjusts the air volume in the area and increases the air leakage resistance to reduce the air leakage to the goaf; and continuously observes the changes in the real-time temperature value after adjustment;

[0016] C. If the real-time temperature value collected by a wireless temperature sensor exceeds 70°C, the fusible cover and fusible plug of the nozzle where the wireless temperature sensor is located will melt due to the heat, and the slurry delivery valve and screw pump will be opened at the same time, so that the fire extinguishing slurry will pass through the slurry delivery pipeline, main pipeline and branch pipeline in turn, and be injected into the goaf through the nozzle of the current nozzle to inhibit the oxidation of the coal in this area;

[0017] D. The current nozzle continues to spray until the temperature value monitored by the wireless temperature sensor is lower than 40°C, at which time the slurry delivery valve and the screw pump are closed to complete the process of inhibiting coal oxidation in this area;

[0018] E. After the grouting is completed, the gas composition of the area is tested. First, the other end of the main pipeline is disconnected from the other end of the slurry delivery pipeline, and then the other end of the main pipeline is connected to the gas collector through a connecting pipe. The gas collector collects the gas data of the area through the nozzle that completes the grouting. The gas analyzer analyzes and processes the gas data collected by the gas collector to obtain the gas data of coal oxidation in the area.

[0019] Compared with the prior art, the present invention adopts a combination of grouting system, automatic spraying system, temperature monitoring system and gas detection system, which has the following advantages:

[0020] (1) Wireless temperature sensors are installed at the nozzles of each automatic shotcrete system. Each nozzle is evenly distributed in the spontaneous combustion area of ​​the goaf, so as to realize real-time monitoring of the temperature of the area, and then it can be understood in real time whether the coal body in the area is oxidized and the oxidation status. If the temperature of a certain area exceeds 40°C but does not reach 70°C, the data processor can send out an early warning signal, and the staff can reduce the air leakage to the goaf by adjusting the air volume in the area and increasing the air leakage resistance, so as to timely and conveniently intervene in the early stage of oxidation of the coal body;

[0021] (2) If the temperature exceeds 70°C, the fusible cover and fusible plug of the current nozzle will melt, and the fire-fighting slurry will enter the area through the nozzle to cover the coal body and control oxidation. At the same time, the nozzle can spray the fire-fighting slurry to the floating coal on the roof of the goaf. There are many options for the slurry to be used according to the on-site operating conditions and the oxidation of the coal body. Compared with traditional fire extinguishing technology, the injected fire-fighting slurry can control the floating coal on the roof, with a wide coverage range, and more targeted to achieve all-round prevention and control of the goaf;

[0022] (3) After the grouting is completed, in order to more accurately and comprehensively understand the oxidation status of the coal body in the goaf, the gas collector is connected to the main pipeline. At this time, the gas can be directly collected by the gas collector for analysis. Since only the nozzle where grouting occurs is connected to the inside of the goaf (that is, only the fusible cover and fusible plug of the nozzle with a regional temperature higher than 70°C are melted, and the other nozzles are not connected), the gas collector can collect the gas composition of the surrounding area, that is, the coal oxidation area. The existing gas collection method is to collect gas by constructing drilling holes, because the drilling holes cannot accurately reach the high-temperature area of ​​coal oxidation, and there are cracks in the drilling holes themselves, and the gas will flow due to air leakage, which ultimately leads to the collected gas being unable to truly reflect the gas composition of the high-temperature area. The present invention does not require additional drilling, directly uses the original grouting pipeline, and can collect the gas closest to the high-temperature area of ​​coal oxidation, and ultimately effectively ensures that the subsequent gas analysis reflects the gas composition of the high-temperature area as much as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 It is a structural schematic diagram of the nozzle in the present invention;

[0025] Figure 3 It is a schematic diagram of the fixed connection between the branch pipeline and the anchor rod in the present invention.

[0026] In the figure: 1. pulping barrel, 2. pneumatic mixer, 3. data transmission line, 4. screw pump, 5. pressure gauge, 6. slurry delivery valve, 7. slurry delivery pipeline, 8. gas analyzer, 9. data processor, 10. data receiver, 11. gas collector, 12. rubber tube, 13. nozzle, 14. spontaneous combustion goaf, 15. branch pipeline, 16. fusible plug, 17. fusible cover, 18. wireless temperature sensor, 19. anchor rod, 20. lower pipe clamp, 21. upper pipe clamp, 22. screws. DETAILED DESCRIPTION

[0027] The present invention will be further described below.

[0028] like Figures 1 to 3 As shown, a device for inhibiting early oxidation of residual coal in goaf includes a grouting system, an automatic grouting system, a temperature monitoring system and a gas detection system;

[0029] The grouting system comprises a slurry barrel 1, a pneumatic mixer 2, a screw pump 4 and a slurry delivery pipeline 7. The pneumatic mixer 2 is installed in the slurry barrel 1. The slurry barrel 1 is connected to the inlet of the screw pump 4 through a pipeline. The outlet of the screw pump 4 is connected to one end of the slurry delivery pipeline 7. The slurry delivery pipeline 7 is equipped with a pressure gauge 5 and a slurry delivery valve 6.

[0030] The automatic shotcrete system comprises a main pipeline and a plurality of branch pipelines 15, one end of the plurality of branch pipelines 15 is blocked and the other end is connected to one end of the main pipeline, each branch pipeline 15 is equipped with a plurality of nozzles 13, the nozzle 13 is composed of a nozzle pipe and a plurality of nozzles, one end of the nozzle pipe is blocked and the other end is connected to the branch pipeline 15, a plurality of nozzles are distributed on the nozzle pipe, each nozzle is provided with a fusible plug 16 inside, and the nozzle is sealed by a fusible cover 17; wherein the fusible cover 17 is used to prevent the top plate debris from falling and blocking the nozzle, and the fusible plug 16 is used to prevent the slurry inside the nozzle from spraying out from the nozzle; the other end of the main pipeline is connected to the other end of the slurry delivery pipeline 7 through a connecting pipe;

[0031] The temperature monitoring system includes a plurality of wireless temperature sensors 18, a data receiver 10 and a data processor 9, wherein the data receiver 10 and the data processor 9 are connected via a data transmission line 3, each wireless temperature sensor 18 is respectively arranged on a nozzle 13, and is used to detect the real-time temperature value of the location of the nozzle 13, and send the detected temperature value via a wireless signal; the data receiver 10 is used to receive the temperature value sent by each wireless temperature sensor 18, and feed the data back to the data processor 9; the data processor 9 analyzes and processes the real-time temperature value, and sends out an early warning signal;

[0032] The gas detection system includes a gas analyzer 8 and a gas collector 11, which are connected by a rubber tube 12. When gas detection is required, the other end of the main pipeline is first disconnected from the other end of the slurry delivery pipeline 7, and then the other end of the main pipeline is connected to the gas collector 11 through a connecting tube. The gas collector 11 collects gas data through each nozzle 13 of the automatic spraying system, and the gas analyzer 8 analyzes and processes the gas data collected by the gas collector 11.

[0033] Furthermore, the fusible cover 17 is made of an indium-bismuth alloy, and its melting temperature is 57°C; the fusible plug 16 is made of a bismuth-tin alloy, and its melting temperature is 70°C.

[0034] Furthermore, the main pipeline and the plurality of branch pipelines 15 are all nylon tubes that can withstand a temperature of 260°C.

[0035] Furthermore, each nozzle 13 has three nozzles, which are staggered on the outer circumference of the nozzle and are oriented at 45° to the axial direction of the nozzle. This method can ensure that the fire extinguishing slurry can inhibit the oxidation of coal in the surrounding area after being sprayed.

[0036] The above-mentioned pulping barrel 1, pneumatic mixer 2, screw pump 4, pressure gauge 5, gas analyzer 8, data receiver 10, data processor 9, gas collector 11 and wireless temperature sensor 18 are all existing devices.

[0037] A working method of equipment for inhibiting early oxidation of residual coal in goaf, the specific steps are:

[0038] A. Install multiple anchor rods 19 at the top plate position of the coal mine goaf area to be tested, evenly lay the branch pipes 15 of the automatic shotcrete system in the natural goaf area 14, and fix the branch pipes 15 with the anchor rods 19 through the lower pipe clamp 20, the upper pipe clamp 21 and the screws 22. Then, determine the raw material ratio of the fire extinguishing slurry according to the actual situation of the coal mine goaf (the fire extinguishing slurry can be water, yellow mud, retardant slurry, gel foam and other known materials), put the required raw materials into the slurry barrel 1, and start the pneumatic mixer 2 to prepare the fire extinguishing slurry; store the temperature alarm threshold value of 40°C in the data processor 9, thereby completing the equipment preparation work;

[0039] B. When starting work, each wireless temperature sensor 18 monitors the temperature value of the location in real time, and feeds it back to the data processor 9 through the data receiver. The data processor 9 compares the real-time temperature value with the temperature alarm threshold. If the real-time temperature value exceeds 40°C, the data processor 9 issues a temperature warning. At this time, the staff adjusts the air volume in the area to increase the air leakage resistance to reduce the air leakage to the goaf; and continuously observes the change of the real-time temperature value after adjustment;

[0040] C. If the real-time temperature value collected by a wireless temperature sensor 18 exceeds 70°C, the fusible cover 17 and the fusible plug 16 of the nozzle 13 where the wireless temperature sensor 18 is located will melt due to the heat, and the slurry delivery valve 6 and the screw pump 4 will be opened at the same time, so that the fire extinguishing slurry will pass through the slurry delivery pipeline 7, the main pipeline and the branch pipeline 15 in sequence, and will be injected into the goaf through the nozzle of the current nozzle 13, so as to inhibit the oxidation of the coal in this area;

[0041] D. The current nozzle 13 continues to spray until the temperature value monitored by the wireless temperature sensor 18 is lower than 40° C. At this time, the slurry delivery valve 6 and the screw pump 4 are closed to complete the process of inhibiting coal oxidation in this area;

[0042] E. After the grouting is completed, the gas composition of the area is detected. First, the other end of the main pipeline is disconnected from the other end of the slurry delivery pipeline 7, and then the other end of the main pipeline is connected to the gas collector 11 through a connecting pipe. The gas collector 11 collects the gas data of the area through the nozzle 13 that completes the grouting. The gas analyzer 8 analyzes and processes the gas data collected by the gas collector 11, so as to obtain the gas data of the coal body oxidation in the area.

Claims

1. A device for inhibiting early oxidation of coal in goaf, characterized in that: Including grouting system, automatic shotcrete system, temperature monitoring system and gas detection system; The grouting system includes a slurry barrel, a pneumatic mixer, a screw pump and a slurry delivery pipeline. The pneumatic mixer is installed in the slurry barrel. The slurry barrel is connected to the inlet of the screw pump through a pipeline. The outlet of the screw pump is connected to one end of the slurry delivery pipeline. The slurry delivery pipeline is equipped with a pressure gauge and a slurry delivery valve. The automatic shotcrete system comprises a main pipeline and a plurality of branch pipelines, one end of the plurality of branch pipelines is blocked and the other end is connected to one end of the main pipeline, and a plurality of nozzles are installed on each branch pipeline, the nozzles are composed of a nozzle and three nozzles, one end of the nozzle is blocked and the other end is connected to the branch pipeline, and the nozzles are staggered on the outer circumference of the nozzle, and the directions of the nozzles are 45° with the axial direction of the nozzle; a fusible plug is arranged inside each nozzle, and the nozzle is sealed by a fusible cover; the fusible plug is made of bismuth-tin alloy, and its melting temperature is 70°C; the other end of the main pipeline is connected to the other end of the slurry delivery pipeline through a connecting pipe; the fusible cover is made of indium-bismuth alloy, and its melting temperature is 57°C; The temperature monitoring system includes a plurality of wireless temperature sensors, a data receiver and a data processor, wherein the data receiver and the data processor are connected via a data transmission line, each wireless temperature sensor is respectively arranged on a nozzle, and is used to detect the real-time temperature value of the nozzle position, and send the detected temperature value via a wireless signal; the data receiver is used to receive the temperature value sent by each wireless temperature sensor, and feed the data back to the data processor; the data processor analyzes and processes the real-time temperature value, and sends out an early warning signal; The gas detection system includes a gas analyzer and a gas collector, which are connected by a rubber tube. When gas detection is required, the other end of the main pipeline is first disconnected from the other end of the slurry delivery pipeline, and then the other end of the main pipeline is connected to the gas collector through a connecting tube. The gas collector collects gas data through each nozzle of the automatic spraying system, and the gas analyzer analyzes and processes the gas data collected by the gas collector.

2. The equipment for inhibiting early oxidation of coal in goaf according to claim 1, characterized in that: The main pipeline and multiple branch pipelines are all nylon tubes that can withstand a temperature of 260°C.

3. A method for operating the equipment for inhibiting early oxidation of residual coal in goaf according to any one of claims 1 and 2, characterized in that: The specific steps are: A. Install multiple anchor rods at the top of the coal mine goaf area to be inspected, evenly lay the branch pipes of the automatic shotcrete system in the natural goaf area, and fix the branch pipes with the anchor rods through the lower pipe clamp, upper pipe clamp and screws. Then, determine the raw material ratio of the fire extinguishing slurry according to the actual situation of the coal mine goaf area, put the required raw materials into the slurry making barrel, and start the pneumatic mixer to prepare the fire extinguishing slurry; store the temperature alarm threshold of 40°C in the data processor, thereby completing the equipment preparation; B. When starting work, each wireless temperature sensor monitors the temperature value of the location in real time and feeds it back to the data processor through the data receiver. The data processor compares the real-time temperature value with the temperature alarm threshold. If the real-time temperature value exceeds 40°C, the data processor issues a temperature warning. At this time, the staff adjusts the air volume in the area and increases the air leakage resistance to reduce the air leakage to the goaf; and continuously observes the changes in the real-time temperature value after adjustment; C. If the real-time temperature value collected by a wireless temperature sensor exceeds 70°C, the fusible cover and fusible plug of the nozzle where the wireless temperature sensor is located will melt due to the heat, and the slurry delivery valve and screw pump will be opened at the same time, so that the fire extinguishing slurry will pass through the slurry delivery pipeline, main pipeline and branch pipeline in turn, and be injected into the goaf through the nozzle of the current nozzle to inhibit the oxidation of the coal in this area; D. The current nozzle continues to spray until the temperature value monitored by the wireless temperature sensor is lower than 40°C, at which time the slurry delivery valve and the screw pump are closed to complete the process of inhibiting coal oxidation in this area; E. After the grouting is completed, the gas composition of the area is tested. First, the other end of the main pipeline is disconnected from the other end of the slurry delivery pipeline, and then the other end of the main pipeline is connected to the gas collector through a connecting pipe. The gas collector collects the gas data of the area through the nozzle that completes the grouting. The gas analyzer analyzes and processes the gas data collected by the gas collector to obtain the gas data of coal oxidation in the area.

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