A local gas outburst elimination system and method for underground coal seams

Abstract

The application provides a local gas outburst suppression system and method for a coal seam underground, the outburst suppression system comprising a monitoring unit and a plurality of capsules; the monitoring unit is a sensor network composed of a plurality of gas sensors and distributed underground, the sensor network monitors the methane concentration and pressure underground in real time and transmits signals to a control system; the capsules are preset in potential outburst areas, the capsule comprises a capsule shell, adsorbing powder encapsulated in the capsule shell, and a blasting device arranged in the capsule shell, and an enabling end of the blasting device is connected with a blasting control end of the control system; when the sensor network monitors that the methane concentration exceeds a threshold value or the gas pressure suddenly rises, the control system controls the blasting device in the capsule to start to release the adsorbing powder in the capsule shell to the outburst area. The application realizes the rapid suppression of gas outburst by presetting the capsules with adsorbing powder, intelligently triggering the release of the adsorbing powder to efficiently adsorb gas.

Description

Technical Field

[0001] This invention belongs to the field of coal mine safety technology, specifically relating to a local gas outburst suppression system and method for underground coal seams. Background Technology

[0002] Coal mine gas outbursts pose a significant safety hazard to underground operations. Traditional methods rely on ventilation dilution or high-pressure grouting, but these suffer from problems such as slow response and low efficiency. In recent years, porous materials (such as activated carbon) have been used for gas adsorption, as disclosed in CN202222032504.4 and CN201910644061.4. However, the adsorption capacity and kinetic properties of activated carbon are insufficient to meet the requirements for rapid outburst suppression.

[0003] A search revealed no publicly available technical solutions similar to this invention. Summary of the Invention

[0004] To address the technical problems existing in the prior art, the first aspect of this invention is to provide a localized gas outburst suppression system for underground coal seams. This system utilizes pre-set capsules containing adsorbent powder, which are intelligently triggered to release the powder for efficient gas adsorption, thereby achieving rapid suppression of gas outbursts. Secondly, based on the same inventive concept, this invention also provides a method for suppressing gas outbursts based on the aforementioned localized gas outburst suppression system for underground coal seams.

[0005] In this embodiment of the invention, a localized coal seam gas outburst mitigation system includes a monitoring unit and several capsules that can release adsorbed powder within them upon triggering by gas concentration. The monitoring unit is a distributed sensor network composed of several gas sensors installed underground. The sensor network monitors the underground methane concentration and gas pressure in real time and transmits the signals to the control system. The capsules are pre-positioned in potential outburst areas. Each capsule includes a capsule shell, adsorbed powder encapsulated in the capsule shell, and a blasting device disposed in the capsule shell. The blasting control terminal of the control system is connected to the enabling terminal of the blasting device. When the sensor network detects that the methane concentration exceeds a threshold or the gas pressure rises sharply, the control system controls the blasting device inside the capsule to activate, thereby releasing the adsorbed powder in the capsule shell to the outburst area.

[0006] An embodiment of the present invention provides a method for localized gas outburst suppression in underground coal seams, based on the aforementioned localized gas outburst suppression system in underground coal seams, comprising the following steps: Pre-setting stage: Based on geological survey results, capsules are pre-set at certain intervals in potential outburst areas; Monitoring stage: A sensor network collects environmental data in real time and uploads it to the control system; Triggered release: When the methane concentration exceeds a threshold or the gas pressure suddenly increases, a blasting device is activated to release adsorbed powder from the capsule shell to the outburst area; Adsorption suppression: The adsorbed powder adsorbs free gas in the outburst area; Material recovery: The adsorbed powder material in the outburst area is recovered by a negative pressure suction device, and recycled after desorption treatment.

[0007] Compared with the prior art, the technical effects achieved by the superior technical solution of the present invention include:

[0008] 1. This invention utilizes a multi-parameter dynamic sensing and intelligent triggering mechanism to rapidly release COFs materials, achieving over 90% gas adsorption in a short time. This effectively improves the efficiency of gas adsorption and control, enabling proactive prevention and control of gas outbursts. It provides a new approach to addressing localized gas outburst problems and has application value in safe coal mining operations and mine gas disaster prevention.

[0009] 2. This invention selects novel three-dimensional covalent organic frameworks (COFs) as materials for rapid gas outburst suppression and reduction of gas concentration. While ensuring high efficiency and environmental protection, it can effectively prevent gas disasters in coal mining faces and improve the safety of coal mining operations.

[0010] 3. This invention overcomes the technical bottlenecks of low adsorption rate and small coverage in traditional gas control, providing an efficient and low-cost solution for the proactive prevention and control of coal mine outburst accidents. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the underground coal seam local gas outburst suppression system in an embodiment.

[0012] The reference numerals in the accompanying drawings include: gas sensor 1, capsule 2, control system 3, and track 4. Detailed Implementation

[0013] Embodiments of the present invention 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 the present invention, and should not be construed as limiting the present invention.

[0014] Example 1

[0015] This embodiment provides a localized gas outburst suppression system for underground coal seams, such as... Figure 1 As shown, in a preferred embodiment, the methane outburst mitigation system includes a monitoring unit and several capsules 2 that can release adsorbed powder within them upon triggering by methane concentration. The monitoring unit is a distributed sensor network located underground, consisting of several gas sensors 1 (including a methane concentration sensor for monitoring methane concentration and a gas pressure sensor for monitoring gas pressure). The signal output terminals of the gas sensors 1 are connected to a control system 3. The sensor network monitors the underground methane concentration and gas pressure in real time and transmits the signals to the control system 3.

[0016] Capsule 2 is pre-installed in potential outburst areas, specifically in high-risk areas such as the roadway roof or coal face. Capsule 2 includes a pressure-resistant and breathable capsule shell, adsorbent powder encapsulated within the capsule shell, and a blasting device housed within the capsule shell. The blasting control terminal of the control system 3 is connected to the enabling terminal of the blasting device. When the sensor network detects that the methane concentration exceeds a threshold (e.g., 1.5%) or a sudden increase in gas pressure (i.e., a pressure surge determined to be caused by a gas leak), it indicates a gas outburst. The control system 3 then activates the blasting device within capsule 2 to release the adsorbent powder from the capsule shell to the outburst area. The adsorbent powder adsorbs the gas, achieving rapid suppression of the gas outburst.

[0017] In this invention, the adsorbent powder is preferably a three-dimensional covalent organic framework (COF) material, more preferably 3D-TFB-COF-Et, and the COF material has an ultra-high specific surface volume (>4400 m³). 2 It features a high density of g / g, narrow pore size distribution (1.1 nm), and excellent high-pressure methane adsorption performance (264 cm⁻¹). 3 / cm 3 (100 bar) can significantly improve gas adsorption efficiency; and the COFs material is recyclable and regenerable, retaining >85% adsorption performance after ten uses, reducing operation and maintenance costs. Further preferably, the capsule shell is made of biodegradable polymers, such as polylactic acid or polyvinyl alcohol, making it more environmentally friendly.

[0018] More preferably, the capsule shell also encapsulates a powdered nano-alumina catalyst. The nano-alumina catalyst is released to the protruding area along with the adsorbent powder (COFs). After release, the COFs material rapidly adsorbs methane due to its microporous structure. At the same time, the premixed nano-alumina catalyst in the capsule shell can promote the oxidation of methane, which in turn promotes the oxidation of methane to produce CO2 and water, further reducing the risk of explosion.

[0019] In this invention, the blasting device inside capsule 2 is a pressure release type device or a jet-type blasting device.

[0020] When the rupture device is a pressure-relief type, a certain pressure is applied inside the capsule shell. When the device is triggered, the force of the explosion or compressed gas causes the capsule shell to rupture or open, ejecting the powder inside. The internal pressure of the capsule shell can be controlled by gas pressurization, chemical reaction, or mechanical devices. For example, a controllable gas compression system can be installed inside the capsule shell, or a soluble membrane or other opening device can be used. When the pressure reaches a preset value, the capsule shell will rupture or open, thus uniformly ejecting the adsorbed powder. This method can achieve a relatively stable and continuous release, ensuring the uniformity of the adsorbed powder.

[0021] When the blasting device is a jet-type blasting device, a jetting device is installed on the capsule shell. When the blasting device is triggered, the powder is ejected from the jetting device by high-pressure gas or a mechanical device. A principle similar to an atomizer can be used to uniformly spray the adsorbed powder in a mist or particle form during blasting. Specifically, miniature nozzles or spray heads can be installed inside the capsule shell. The nozzles are propelled by compressed gas or a mechanical device to push the adsorbed powder through the nozzles to achieve uniform distribution. The orifice diameter of the nozzles can be adjusted to improve powder distribution, allowing for more efficient powder uniformity through precise nozzle design.

[0022] like Figure 1 As shown, in another preferred embodiment, capsule 2 is mounted on track 4 and can move on track 4. Depending on the range of gas concentration, capsule 2 can move to areas with high gas concentration to release gas, preventing a shortage of capsule 2 in one area from being supplemented by moving capsule 2 from other areas with sufficient gas concentration. Specifically, the method of moving capsule 2 on track 4 can adopt existing technology, such as the method of moving spotlights on tracks, or the method of moving the hooks of electric curtains on tracks.

[0023] In another preferred embodiment, capsule 2 has nested multi-layered capsule shells, each containing adsorbent powder and a bursting device; that is, a large capsule contains a smaller capsule, and the smaller capsule contains even smaller capsules. The multi-layered capsule shells can burst simultaneously or at different times. During timed bursting, the shells burst layer by layer from the outside in, and the direction angle of the adsorbent powder released from each layer is adjustable. The bursting time and direction angle of each layer of capsule 2 are controllable, and the layered bursting prevents excessive adsorbent powder from being sprayed in one area at a time, leaving other areas without sufficient powder, resulting in poor effectiveness.

[0024] In another preferred embodiment, the outburst mitigation system further includes a negative pressure suction device located in the outburst area for removing exposed COFs powder from the well. After outburst mitigation, the COFs material is recovered via the negative pressure suction device, desorbed, and then recycled.

[0025] Example 2

[0026] This embodiment provides a method for eliminating coal seam local gas outbursts based on the underground coal seam local gas outburst elimination system of Embodiment 1, including the following steps:

[0027] Pre-setting stage: Based on the geological survey results, pre-set capsules at certain intervals in potential protrusion areas, with a capsule spacing of ≤5m.

[0028] Monitoring phase: The sensor network collects environmental data in real time and uploads it to the control system, using machine learning algorithms to predict prominent risks.

[0029] Triggered release: When the methane concentration exceeds a threshold (e.g., 1.5%) or the gas pressure suddenly increases, the detonation device is activated to release the adsorbed powder in the capsule shell to the protruding area. The COFs material diffuses in a mist-like manner, covering an area ≥10m. 3 .

[0030] Adsorption and explosion mitigation: The adsorption powder adsorbs free methane in the protruding area. COFs can adsorb more than 80% of the free methane within 1 minute. At the same time, the nano alumina catalyst catalyzes the oxidation of the remaining methane to produce CO2 and water, further reducing the risk of explosion.

[0031] Material recycling: COFs material from the protruding area is recovered afterward using a negative pressure suction device, and then recycled after desorption treatment.

[0032] In a preferred embodiment of the present invention, all capsules are uniformly mounted on a track, and a traveling mechanism can control the capsules to move along the track. The moving method is as follows:

[0033] A three-dimensional spatial model of the gas monitoring area can be obtained (which can be constructed by laser scanning, which is existing technology and will not be elaborated here), as well as the real-time coordinates of the gas sensor and capsule. Position sensors or positioning devices can be set on the gas sensor and capsule to determine the location.

[0034] The gas sensor detects real-time methane concentration and pressure values ​​and uploads them to the control system;

[0035] If the methane concentration in certain areas exceeds the threshold or the gas pressure rise exceeds the threshold (i.e., the gas pressure rises sharply), the volume, actual methane concentration, and pressure of the areas exceeding the threshold are obtained to determine the required number of capsules.

[0036] The movement of capsules is controlled according to the required number of capsules in different areas.

[0037] In this invention, the method for determining the required number of capsules by obtaining the volume of the region exceeding the threshold, the actual methane concentration, and the pressure is as follows:

[0038] The location of gas sensors that exceed the threshold for methane concentration or pressure rise value;

[0039] In the three-dimensional spatial model of the gas monitoring area, determine whether there are adjacent gas sensors in the six directions of up, down, front, back, left, and right for the gas sensor exceeding the standard. If there are adjacent gas sensors in some directions, determine the central symmetry plane of the gas sensor exceeding the standard and the adjacent gas sensor in that direction (the plane passing through the midpoint of the line connecting the two gas sensors and perpendicular to the line connecting them). If there are no adjacent gas sensors in some directions, obtain the distance from the gas sensor exceeding the standard to the wall or ground in that direction, and determine the volume of the area corresponding to each gas sensor exceeding the standard (the volume enclosed by the six faces, such as the nearest central symmetry plane, the wall, or the ground, corresponding to each gas sensor exceeding the standard, which can be approximated by the volume of a cuboid), that is, the volume of the area to be treated.

[0040] Determine the number of capsules needed for the i-th region to be processed:

[0041] in, The floor symbol is m. t i represents the number of capsules required for the i-th region to be treated at time t, m0 represents the number of capsules required per unit region to be treated when the methane concentration is at the methane concentration threshold and the pressure change is less than the pressure change threshold, and s0 represents the volume of the unit region to be treated. i Let η be the volume of the i-th region to be processed, η0 be the methane concentration threshold, and η ti Let p be the gas concentration of the i-th region to be treated at time t. o p is the pressure rise threshold. ti Let t be the pressure rise of the i-th region to be treated relative to the pressure threshold. If a region to be treated has a high methane concentration, a rapid pressure rise, or a large volume, it will require a large number of capsules. The aforementioned formula is used to determine in a timely manner whether there are enough capsules for that region.

[0042] If the number of capsules currently in the i-th region to be processed is greater than or equal to the number of capsules required, then the required number of capsules are opened evenly (for example, if the number of capsules currently in the region to be processed is five and the number of capsules required is three, then the three capsules in the middle and two ends are opened). If the number of capsules currently in the i-th region to be processed is less than the number of capsules required, then capsules are moved from the nearest neighboring surplus region to make up the difference (if a region to be processed does not have enough capsules, several regions can be moved to make up the difference. When moving, the capsules are moved sequentially. That is, if there are three regions to be processed, each region originally has three capsules, but it is calculated that the third region to be processed needs five capsules, while the first and second regions to be processed only need two capsules, then the second region to be processed gives two capsules to the third region to be processed, and the first region to be processed gives one capsule to the second region to be processed).

[0043] If there are no spare capsules, or if the spare capsules are insufficient after replenishment, increase ventilation and sound an emergency alarm. Alternatively, when the number of capsules remaining is low (e.g., only one capsule remains in each area), send a signal to the wellhead to replenish the capsules.

[0044] Although embodiments of the invention 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 the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for localized gas outburst suppression in underground coal seams, implemented using an underground coal seam localized gas outburst suppression system, characterized in that... The methane outburst mitigation system includes a monitoring unit and several capsules that can release adsorbed powder within them, triggered by methane concentration. The monitoring unit is a distributed sensor network consisting of several methane sensors installed downhole. The sensor network monitors the downhole methane concentration and gas pressure in real time and transmits the signals to the control system. The capsules are pre-positioned in potential outburst areas. Each capsule includes a capsule shell, adsorbed powder encapsulated in the capsule shell, and a blasting device located in the capsule shell. The blasting control terminal of the control system is connected to the enabling terminal of the blasting device. When the sensor network detects that the methane concentration exceeds a threshold or the gas pressure rises sharply, the control system activates the blasting device inside the capsule to release the adsorbed powder in the capsule shell to the outburst area. The anti-protrusion method includes the following steps: Pre-planning stage: Based on the geological survey results, pre-plan capsules at certain intervals in potential protrusion areas; Monitoring phase: The sensor network collects environmental data in real time and uploads it to the control system; Triggered release: When the methane concentration exceeds the threshold or the gas pressure rises sharply, the explosion device is activated to release the adsorbed powder in the capsule shell to the protruding area; Adsorption to eliminate gas spikes: Adsorption powder adsorbs free gas in the spiked area; Material recycling: The adsorbed powder material in the protruding area is recovered by a negative pressure suction device, and then recycled after desorption treatment; The capsules are uniformly installed on the track, and the walking mechanism can control the capsules to move along the track. The movement method is as follows: acquire a three-dimensional spatial model of the gas monitoring area, as well as the real-time coordinates of the gas sensor and the capsules; the gas sensor detects and uploads the real-time methane concentration and pressure values; if the methane concentration or pressure rise value in some areas exceeds the threshold, acquire the volume, actual methane concentration, and pressure of the areas exceeding the threshold to determine the required number of capsules; control the movement of the capsules according to the required number of capsules in different areas. Specifically, the method for determining the required number of capsules by obtaining the volume of the region exceeding the threshold, the actual methane concentration, and the pressure is as follows: The location of gas sensors that exceed the threshold for methane concentration or pressure rise value; In the three-dimensional spatial model of the gas monitoring area, determine whether the gas sensor exceeding the standard has adjacent gas sensors in the six directions of up, down, front, back, left, and right. If there are adjacent gas sensors in some directions, determine the central symmetry plane between the gas sensor exceeding the standard and the adjacent gas sensors in that direction. If there are no adjacent gas sensors in some directions, obtain the distance of the gas sensor exceeding the standard from the wall or ground in that direction, and determine the volume of the area corresponding to each gas sensor exceeding the standard, that is, the volume of the area to be processed. Determine the number of capsules needed for the i-th region to be processed: ， in," " is the rounding up symbol. Let be the number of capsules needed for the i-th region to be processed at time t. This refers to the number of capsules required per unit area to be treated when the methane concentration is at the methane concentration threshold and the pressure change is less than the pressure change threshold. The unit is the volume of the area to be processed. Let i be the volume of the i-th region to be processed. The methane concentration threshold, Let be the gas concentration in the i-th region to be treated at time t. The pressure rise threshold, Let be the pressure rise of the i-th region to be processed at time t relative to the pressure threshold; If the number of capsules in the i-th region to be processed is greater than or equal to the number of capsules required, then the required number of capsules are opened evenly. If the number of capsules in the i-th region to be processed is less than the number of capsules required, then capsules are moved from the nearest neighboring surplus region to make up the difference.

2. The method for localized gas outburst suppression in underground coal seams according to claim 1, characterized in that, The blasting device is a pressure relief type device or a jet blasting type device; When the blasting device is a pressure relief device, by applying a certain pressure inside the capsule shell, when the blasting device is triggered, the capsule shell is broken or opened by the force of the explosion or compressed gas, so as to spray out the powder inside the capsule shell. When the blasting device is a jet-type blasting device, a jetting device is installed on the capsule shell. When the blasting device is triggered, the powder is ejected from the jetting device by high-pressure gas or mechanical device.

3. The method for localized gas outburst suppression in underground coal seams according to claim 1, characterized in that, The capsule has multiple nested capsule shells, each containing the adsorbent powder and a bursting device. The multiple capsule shells can burst simultaneously or at different times. During the time-sharing burst, the capsules burst layer by layer from the outside to the inside. The direction angle of the adsorbent powder released from each capsule shell is adjustable.

4. The method for localized gas outburst suppression in underground coal seams according to claim 1, characterized in that, The adsorbent powder is a covalent organic framework (COF) material; And / or the capsule shell is made of a biodegradable polymer material.

5. A method for localized gas outburst suppression in underground coal seams according to claim 4, characterized in that, The capsule shell also encapsulates a powdered nano-alumina catalyst, which is released along with the adsorbed powder to the protruding area. The nano-alumina catalyst promotes the oxidation of methane to produce CO2 and water.

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