A sealed wall outer blind lane area gas accumulation treatment device and method

Abstract

The present application relates to a kind of coal mine safety field of preventing and treating the closed wall outer blind lane area gas accumulation treatment device and method, to solve the technical problem that closed wall outside blind lane gas accumulation lacks automated, normal treatment means.The present application monitors blind lane gas concentration in real time by gas concentration sensor, according to the comparison result of monitoring value and preset threshold value, in low concentration, using full air pressure ventilation inlet to introduce lane airflow for normal dilution, in high concentration, start air blower and press airflow into air cylinder to form enhanced ventilation and reduce concentration quickly, and after concentration falls to safety value, stop automatically and restore low energy consumption mode.The present application is mainly used for the automatic treatment of gas accumulation in the blind lane area outside the closed wall in coal mine.

Description

Technical Field

[0001] This invention belongs to the field of coal mine ventilation and safety technology, specifically relating to a device and method for controlling gas accumulation in blind alleyways outside sealed walls. Background Technology

[0002] In underground coal mine operations, permanent or temporary sealing walls are typically constructed to isolate abandoned roadways, goaf areas, and production areas from ventilation, and to prevent toxic and harmful gases from entering the working face. However, due to factors such as construction techniques and mine pressure manifestations, these sealing walls in goaf areas are prone to cracking, making it difficult to completely isolate gases from the outside. Simultaneously, influenced by dynamic pressure differences in the underground ventilation system, high-concentration methane gas inside the goaf can leak out through cracks in the sealing walls, forming high-concentration methane accumulation zones in blind roadways outside the walls, posing a safety threat to personnel who accidentally enter these areas.

[0003] Blind alleys outside sealed walls are ventilation dead zones where airflow is stagnant and ventilation is poor. Without a continuous and stable supply of fresh air, leaked gas cannot diffuse and be discharged naturally. Over time, the gas concentration can easily exceed the limit, making them high-risk areas for underground gas exceedances and personnel asphyxiation accidents. They are key areas for ventilation and safety control in coal mines.

[0004] The current "Coal Mine Safety Regulations" require regular monitoring of gas concentration in enclosed external blind roadways, but lack supporting, practical, and routine gas control technologies. Currently, the coal mining industry lacks comprehensive control methods and equipment specifically designed for gas accumulation in enclosed external blind roadways; it can only conduct single-point gas concentration monitoring and lacks proactive, automated, and routine control measures.

[0005] In summary, the field of gas control in closed external blind alleys has long lacked a complete set of intelligent and long-term governance technologies. Relying solely on manual detection and temporary emergency measures has resulted in significant safety management loopholes, and relevant technical solutions are urgently needed to fill the industry gap. Summary of the Invention

[0006] This invention provides a device and method for controlling gas accumulation in blind alley areas outside sealed walls, in order to solve the technical problem of the lack of complete, intelligent and long-term control methods in the prior art.

[0007] To achieve the aforementioned goal of intelligent gas management in blind alleys outside sealed walls, this invention provides a technical solution for a positive pressure ventilation intelligent adjustment system. This solution is based on real-time monitoring values ​​from gas concentration sensors and employs a normalized dilution process using positive pressure ventilation and a graded automatic blower ventilation process. When the gas concentration is low, normalized dilution of the gas concentration in the sealed external blind alley area is achieved through full-pressure ventilation. When the gas concentration exceeds the standard, ventilation is automatically intensified to rapidly reduce the concentration, balancing safety and operational economy.

[0008] According to an embodiment of the present invention, a gas accumulation control device for a blind alley area outside a sealed wall includes a ventilation duct, a blower, a sensor, and a PLC control box. The ventilation duct is a three-way composite anti-static and anti-flame ventilation duct, installed below the top of the alley outside the sealed wall, and has two air inlets and one air outlet. The air outlet faces the gas accumulation area on the roof of the blind alley area outside the sealed wall, and one of the air inlets is a full-pressure ventilation inlet. The blower is a mine explosion-proof blower, installed at the other air inlet of the ventilation duct. The sensor is a gas concentration sensor, installed on the top of the outer side of the sealed wall and located in the blind alley area, for real-time monitoring of the gas concentration in the blind alley area. The PLC control box is a mine explosion-proof and intrinsically safe programmable PLC control box, installed in the alley outside the sealed wall and located on the air inlet side, electrically connected to both the sensor and the blower, for receiving the monitoring data from the sensor, and controlling the start and stop of the blower according to a first preset threshold and a second preset threshold.

[0009] According to one embodiment of the present invention, when the airflow direction in the tunnel is from left to right, the sensor is arranged on the top left side of the outer side of the sealed wall, the air duct is installed in the left tunnel outside the sealed wall, and the full-pressure ventilation inlet is located on the left side and the outlet is located on the right side; when the airflow direction in the tunnel is from right to left, the sensor is arranged on the top right side of the outer side of the sealed wall, the air duct is installed in the right tunnel outside the sealed wall, and the full-pressure ventilation inlet is located on the right side and the outlet is located on the left side.

[0010] According to one embodiment of the present invention, the air outlet is installed directly below the gas accumulation area on the roof of the blind alley outside the sealed wall, and the air outlet is directed toward the gas accumulation area on the roof.

[0011] According to one embodiment of the present invention, the axial direction of the full-pressure ventilation inlet is perpendicular to the axial direction of the outlet.

[0012] According to one embodiment of the present invention, both air inlets are oriented upstream of the airflow in the tunnel.

[0013] This invention also provides a method for controlling gas accumulation in blind alleyways outside sealed walls, using the aforementioned gas accumulation control device for blind alleyways outside sealed walls, comprising the following steps: Step 1: The sensor monitors the gas concentration data in the blind alleyway area in real time and uploads it to the PLC control box; Step 2: When the sensor monitoring value is less than a first preset threshold, the positive pressure guiding effect of the mine's full-pressure ventilation is used to allow airflow from the full-pressure ventilation inlet into the ventilation duct, and then deliver fresh airflow to the blind alleyway area through the outlet to dilute the gas; Step 3: When the sensor monitoring value is greater than or equal to the first preset threshold, the PLC control box sends an start command to the blower, the blower starts and forces airflow into the ventilation duct, forming enhanced ventilation to quickly reduce the gas concentration in the blind alleyway area; Step 4: When the sensor monitoring value is less than a second preset threshold, the PLC control box sends a stop command to the blower, the blower stops working, and the ventilation duct resumes the full-pressure ventilation operation mode, completing the closed-loop control.

[0014] According to one embodiment of the present invention, in step two, when the sensor monitoring value is less than a first preset threshold, the blower is in a stopped state.

[0015] According to one embodiment of the present invention, the first preset threshold is 0.5%, and the second preset threshold is 0.1%.

[0016] According to one embodiment of the present invention, both the first preset threshold and the second preset threshold can be customized on-site through background editing.

[0017] This invention proposes a complete positive pressure intelligent ventilation system and integrated intelligent supporting devices to construct a feasible and routine gas control system, reducing the safety hazard of personnel accidentally entering enclosed blind alleys and suffocating. Compared with existing technologies, the beneficial effects of this invention are: 1) This invention, by deploying a positive pressure ventilation intelligent regulation subsystem, utilizes a gas concentration sensor for real-time monitoring, a PLC control box for automatic judgment and decision-making, and a blower for on-demand start and stop, forming a complete closed-loop control link of perception, decision-making, and execution. The entire process requires no manual intervention, solving the problems of response lag and control blind spots that exist in traditional manual detection and temporary emergency measures, and filling the industry gap in the complete set of technologies for the normalized treatment of gas in closed external blind alleys.

[0018] 2) This invention employs a graded automatic blower and ventilation process. During periods of low methane concentration, normal dilution can be achieved solely through the positive pressure ventilation of the mine's full-pressure ventilation system, without consuming electrical energy. When the methane concentration exceeds the standard, the blower automatically starts to enhance ventilation and rapidly reduce the concentration. Once the concentration returns to a safe range, the blower automatically shuts down and returns to low-energy mode. By switching between low-energy full-pressure ventilation and on-demand automatic strong ventilation in a dual-mode configuration, the operating energy consumption is significantly reduced while ensuring that the methane concentration in blind alleys remains within a safe range. This avoids equipment wear and energy waste caused by prolonged continuous operation of the blower.

[0019] 3) This invention is based on real-time monitoring data from a gas concentration sensor and automatic control logic from a PLC control box. When the gas concentration reaches the activation threshold, the blower automatically starts to achieve pulsed strong ventilation, quickly diluting the gas accumulated in blind alleys; when the concentration drops to the shutdown threshold, it automatically shuts off, forming a closed-loop management system. Compared to the traditional mode of manually inspecting and then temporarily setting up ventilation equipment after discovering exceedances, the response time is significantly shortened and the management efficiency is significantly improved.

[0020] 4) This invention uses a positive pressure ventilation intelligent adjustment system to ensure a constant supply of fresh air to the sealed outer blind alley area, keeping the gas concentration within a safe range. This effectively eliminates the safety hazard of personnel suffocation caused by gas accumulation and improves the level of ventilation and safety assurance in coal mines.

[0021] 5) The ventilation duct, blower, sensor and PLC control box involved in this invention are all existing mature equipment in mining, which do not require special customization and development and have low modification costs; the three ventilation duct adopts a double air inlet structure design, which can be connected to full air pressure ventilation or equipped with a blower. It has a compact structure, occupies little space, and is suitable for various underground closed wall blind alley scenarios, and has good prospects for promotion and application. Attached Figure Description

[0022] Figure 1 This is a top view of the positive pressure airflow intelligent regulation subsystem of the present invention; Figure 2 This is a side view of the positive pressure airflow intelligent regulation subsystem of the present invention; Figure 3 This is a front view of the positive pressure airflow intelligent regulation subsystem of the present invention.

[0023] Figure 4 This is a flowchart of the gas accumulation control process in blind alleys outside the sealed wall of this invention; The labels in the diagram are: 1. Goaf; 2. Sealed wall; 3. Blind alley area; 4. Ventilation duct; 5. Blower; 6. Sensor; 7. PLC control box; 8. Roadway; 9. Air outlet; 10. Full-pressure ventilation inlet; 11. Roadway airflow direction. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1: like Figures 1 to 3 As shown, this embodiment provides a gas accumulation control device for blind alley areas outside sealed walls, including a ventilation duct 4, a blower 5, a sensor 6, and a PLC control box 7. The ventilation duct 4, blower 5, sensor 6, and PLC control box 7 constitute a positive pressure ventilation intelligent regulation subsystem.

[0026] Ventilation duct 4 is a three-way composite anti-static and flame-retardant ventilation duct, installed below the top of the alleyway 8 outside the sealed wall 2. Ventilation duct 4 has two air inlets and one air outlet 9. One air inlet is a full-pressure ventilation inlet 10, and the other air inlet is equipped with a blower 5. The air outlet 9 faces the gas accumulation area on the roof of the blind alleyway area 3 outside the sealed wall 2.

[0027] Preferably, both air inlets face upstream of the airflow 11 in the tunnel. This arrangement ensures that both air inlets can face the direction of the incoming wind, guaranteeing that fresh external airflow can smoothly enter the ventilation duct 4 regardless of whether it is in full-pressure ventilation mode or forced ventilation mode with a blower, reducing airflow deflection losses and improving ventilation efficiency.

[0028] Preferably, the air outlet 9 is installed directly below the gas accumulation area on the roof of the blind alleyway 3, so that the air outlet 9 is directed towards the gas accumulation area on the roof, thereby directly delivering fresh air to the part where gas is most likely to accumulate. In this embodiment, the axial direction of the full-pressure ventilation inlet 10 is perpendicular to the axial direction of the air outlet 9, so as to achieve a reasonable layout within the limited alleyway space.

[0029] Blower 5 is a mine explosion-proof blower, which is installed at another air inlet of the ventilation duct 4. It is used to force the external airflow into the ventilation duct 4 when the gas concentration exceeds the standard, so as to form enhanced ventilation.

[0030] Sensor 6 is a gas concentration sensor, installed on the top outer side of the sealed wall 2 and located within the blind alley area 3, for real-time monitoring of the gas concentration within the blind alley area 3. The specific installation position of sensor 6 is determined according to the airflow direction in the alley: when the airflow direction is from left to right, sensor 6 is placed on the top left side of the outer side of the sealed wall 2; when the airflow direction is from right to left, sensor 6 is placed on the top right side of the outer side of the sealed wall 2. This arrangement ensures that sensor 6 is located upstream of the gas accumulation zone in the blind alley area, achieving accurate monitoring.

[0031] The PLC control box 7 is a mine-use explosion-proof and intrinsically safe programmable PLC control box, installed in the roadway 8 outside the sealed wall 2 and located on the air intake side. It is electrically connected to both the sensor 6 and the blower 5. The PLC control box 7 is used to receive monitoring data from the sensor 6 and control the start and stop of the blower 5 according to the first preset threshold and the second preset threshold.

[0032] When the airflow direction 11 in the tunnel is from left to right, the ventilation duct 4 is installed on the left side of the tunnel outside the sealed wall 2, with the full-pressure ventilation inlet 10 located on the left and the outlet 9 on the right. When the airflow direction 11 in the tunnel is from right to left, the ventilation duct 4 is installed on the right side of the tunnel outside the sealed wall 2, with the full-pressure ventilation inlet 10 located on the right and the outlet 9 on the left. This arrangement ensures that the full-pressure ventilation inlet 10 faces the upstream direction of the tunnel airflow, effectively receiving fresh airflow from the tunnel.

[0033] In this embodiment, the PLC control box 7 has a first preset threshold of 0.5% and a second preset threshold of 0.1%, meaning the start-up threshold for the blower 5 is 0.5% and the stop-down threshold is 0.1%, effectively preventing frequent start-ups and stops of the blower 5 and thus avoiding equipment damage. These thresholds are set according to the relevant provisions on methane concentration in the "Coal Mine Safety Regulations," following the principle of lower methane concentration for safety. Preferably, both the first and second preset thresholds can be customized on-site through background editing, allowing the mine to flexibly adjust them according to its own methane emission patterns, ventilation conditions, and safety management requirements to adapt to different treatment needs under different working conditions.

[0034] As specific selections for each component in this embodiment, the ventilation duct 4 adopts a three-way composite ventilation duct with antistatic and flame-retardant properties. The diameter of the ventilation duct is determined according to the roadway cross-section and ventilation volume requirements, preferably 300mm to 600mm. The blower 5 adopts a mine explosion-proof axial flow or centrifugal explosion-proof blower. Its rated power and air volume are determined according to the volume of the blind roadway area and the gas emission rate, preferably 100m³ / min to 500m³ / min. The sensor 6 adopts a mine gas concentration sensor. The detection principle is catalytic combustion, thermal conductivity or infrared. The detection range is preferably 0 to 100% CH4. The output signal is 4 to 20mA or RS485 digital signal, and it is connected to the PLC control box 7 for communication. The PLC control box 7 has a built-in embedded control program, which has data acquisition, logic judgment, instruction output and data communication functions. It is equipped with a display unit and human-machine interface, and supports on-site modification of threshold parameters and remote background editing. The above specific parameters are for illustrative purposes only and can be adjusted according to the specific working conditions of the mine in actual applications.

[0035] The assembly process of the positive pressure ventilation intelligent regulation subsystem is as follows: First, sensor 6 is installed on the top outside of the sealed wall 2, so that sensor 6 is located in the blind alley area 3; at the same time, PLC control box 7 is installed in the alley 8 outside the sealed wall 2 and located on the air inlet side, and sensor 6 is electrically connected to PLC control box 7. Second, the ventilation duct 4 is suspended below the top of the alley 8 outside the sealed wall 2. The ventilation duct 4 has two air inlets and one air outlet 9. One air inlet is used to install blower 5, and the other air inlet serves as the full-pressure ventilation air inlet 10. Blower 5 is installed at the other air inlet of ventilation duct 4, and the air outlet 9 is directed towards the gas accumulation area on the roof of the blind alley area 3 outside the sealed wall 2. Finally, blower 5 is electrically connected to PLC control box 7.

[0036] This invention is applicable to gas accumulation control scenarios in blind alleyways outside sealed walls in various coal mines, particularly in situations where sealed walls in goaf areas develop cracks due to mine pressure, resulting in continuous gas leakage and unstable outflow rates; scenarios where the space in sealed blind alleyways is limited and large ventilation equipment cannot be installed; and blind alleyway control areas where personnel inspection is difficult or the safety risks are high. This invention utilizes a graded automatic ventilation and air guiding process to adaptively match control requirements under different outflow intensities. It features a compact structure, small footprint, and flexible deployment in narrow alleyways, while achieving fully automated closed-loop control, significantly reducing the frequency of manual inspections and the probability of personnel exposure to hazardous areas.

[0037] Example 2: See Figure 4 This embodiment provides a method for controlling gas accumulation in blind alley areas outside sealed walls, using the gas accumulation control device for blind alley areas outside sealed walls described in Embodiment 1, and includes the following steps: Step 1: Sensor 6 monitors the gas concentration data in the blind alley area 3 in real time and uploads it to the PLC control box 7.

[0038] Step Two: When the value monitored by sensor 6 is less than the first preset threshold, the positive pressure guiding effect of the mine's full-pressure ventilation system is used to allow airflow from the full-pressure ventilation inlet 10 into the ventilation duct 4, and then through the outlet 9 to deliver fresh airflow to the blind tunnel area 3 to dilute the methane. Under this condition, the blower 5 is stopped, and low-energy, normalized dilution is achieved solely through the mine's full-pressure ventilation system.

[0039] Step 3: When the value monitored by sensor 6 is greater than or equal to the first preset threshold, PLC control box 7 sends an start command to blower 5. Blower 5 turns on and forces airflow into air duct 4 to form enhanced ventilation, so as to quickly reduce the gas concentration in blind alley area 3.

[0040] Step 4: When the value monitored by sensor 6 is less than the second preset threshold, PLC control box 7 sends a stop command to blower 5, blower 5 stops working, and air duct 4 resumes full-pressure ventilation operation mode, completing closed-loop treatment.

[0041] The working principle of this invention is as follows: After the device is installed, sensor 6 continuously monitors the gas concentration in the blind alley area 3 outside the sealed wall 2 in real time and uploads the monitoring data to the PLC control box 7. The PLC control box 7 makes real-time judgments on the monitored values: When the monitored value is lower than the first preset threshold, such as 0.5%, it indicates that the gas concentration in the blind alley area is within a safe range. At this time, the dilution effect can be maintained solely by the positive pressure ventilation of the mine's full-pressure ventilation system. The airflow in the all-pressure ventilation system naturally enters the ventilation duct 4 from the air inlet 10 and is then transported to the gas accumulation area on the roof of the blind alley area 3 through the outlet 9, achieving normalized dilution. This mode does not consume electricity and has low operating costs.

[0042] When the monitored value rises to or above the first preset threshold, it indicates that the positive pressure ventilation dilution rate is insufficient to maintain the safety of the gas concentration. The PLC control box 7 immediately sends an start command to the blower 5, and the blower 5 starts running, forcibly pressing a large amount of fresh air into the air duct 4, and quickly delivering it to the blind alley area 3 through the air outlet 9, forming pulse-type enhanced ventilation, which rapidly dilutes and reduces the gas concentration.

[0043] When the monitored value falls back to the second preset threshold, such as below 0.1%, it indicates that the gas concentration in the blind alley area has returned to a safe low level. The PLC control box 7 sends a stop command to the blower 5, the blower 5 automatically stops, and the device automatically switches back to the low-energy full-pressure ventilation mode, waiting for the next treatment cycle.

[0044] This cycle repeats continuously, achieving fully automated, closed-loop, and long-term management of gas accumulation in enclosed external blind alleys.

[0045] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A device for controlling gas accumulation in blind alley areas outside sealed walls, characterized in that, include: Ventilation duct (4), the ventilation duct (4) is a three-way composite anti-static and anti-flame ventilation duct, which is installed below the top of the alley (8) outside the sealed wall (2), and has two air inlets and one air outlet (9). The air outlet (9) faces the gas accumulation area on the roof of the blind alley area (3) outside the sealed wall (2), and one of the air inlets is a full-pressure ventilation air inlet (10). Blower (5), the blower (5) is a mine explosion-proof blower, which is installed at another air inlet of the air duct (4); Sensor (6), the sensor (6) is a gas concentration sensor, which is installed on the top of the outside of the sealed wall (2) and located in the blind alley area (3) for real-time monitoring of the gas concentration in the blind alley area (3); The PLC control box (7) is a mine explosion-proof and intrinsically safe programmable PLC control box. It is installed in the roadway (8) outside the sealed wall (2) and located on the air intake side. It is electrically connected to the sensor (6) and the blower (5) to receive the monitoring data of the sensor (6) and control the start and stop of the blower (5) according to the first preset threshold and the second preset threshold.

2. The gas accumulation control device for blind alley areas outside the sealed wall according to claim 1, characterized in that, When the airflow (11) direction in the tunnel is from left to right, the sensor (6) is arranged on the top left side of the outer side of the sealed wall (2), the air duct (4) is installed on the left side of the tunnel outside the sealed wall (2), and the full-pressure ventilation inlet (10) is located on the left side and the outlet (9) is located on the right side. When the airflow (11) in the tunnel is from right to left, the sensor (6) is arranged on the top right side of the outer side of the sealed wall (2), the air duct (4) is installed on the right side of the tunnel outside the sealed wall (2), and the full-pressure ventilation inlet (10) is located on the right side and the outlet (9) is located on the left side.

3. The gas accumulation control device for blind alley areas outside the sealed wall according to claim 1, characterized in that, The air outlet (9) is installed directly below the gas accumulation area on the roof of the blind alley area (3) outside the sealed wall (2), and the air outlet (9) is directed towards the gas accumulation area on the roof.

4. The gas accumulation control device for blind alley areas outside the sealed wall according to claim 1, characterized in that, The axial direction of the full-pressure ventilation inlet (10) is perpendicular to the axial direction of the outlet (9).

5. The gas accumulation control device for blind alley areas outside the sealed wall according to claim 1, characterized in that, Both air inlets are oriented upstream of the airflow (11) in the tunnel.

6. A method for controlling gas accumulation in blind alley areas outside sealed walls, characterized in that, The gas accumulation control device for blind alley areas outside the sealed wall as described in any one of claims 1 to 5 includes the following steps: Step 1: The sensor (6) monitors the gas concentration data in the blind alley area (3) in real time and uploads it to the PLC control box (7). Step 2: When the value monitored by the sensor (6) is less than the first preset threshold, the positive pressure guiding effect of the mine full-pressure ventilation is used to allow the roadway airflow to enter the air duct (4) from the full-pressure ventilation inlet (10) and deliver fresh airflow to the blind roadway area (3) through the air outlet (9) to dilute the gas; Step 3: When the value monitored by the sensor (6) is greater than or equal to the first preset threshold, the PLC control box (7) sends an opening command to the blower (5), the blower (5) turns on and forces the airflow into the air duct (4) to form enhanced ventilation, so as to quickly reduce the gas concentration in the blind alley area (3); Step 4: When the value monitored by the sensor (6) is less than the second preset threshold, the PLC control box (7) sends a stop command to the blower (5), the blower (5) stops working, and the air duct (4) resumes the full-pressure ventilation operation mode, thus completing the closed-loop treatment.

7. The method for controlling gas accumulation in blind alley areas outside sealed walls according to claim 6, characterized in that, In step two, when the value monitored by the sensor (6) is less than the first preset threshold, the blower (5) is in a stopped state.

8. The method for controlling gas accumulation in blind alley areas outside sealed walls according to claim 6, characterized in that, The first preset threshold is 0.5%, and the second preset threshold is 0.1%.

9. The method for controlling gas accumulation in blind alley areas outside sealed walls according to claim 6, characterized in that, Both the first preset threshold and the second preset threshold can be customized on-site through background editing.

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