A real-time monitoring and early warning device for underground gas extraction in coal mines

Abstract

This invention relates to a real-time monitoring and early warning device for methane concentration in underground coal mines. It includes an outer shell located deep within a casing, with a deep concentration monitoring component located at one end of the outer shell near the depth of the monitoring hole. The deep concentration monitoring component includes an infrared absorption sensor. A sealing and tightening component for connection with the inner wall of the casing is also located in the middle of the outer shell. This invention enables monitoring and early warning of methane concentration deep within the monitoring hole, detecting deep methane anomalies 10-30 minutes in advance, thus improving the safety of power outages and evacuation.

Description

Technical Field

[0001] This invention relates to the field of gas concentration monitoring equipment technology, and in particular to a real-time monitoring and early warning device for gas concentration in underground coal mines. Background Technology

[0002] Gas drainage is a crucial aspect of safe coal mine production. During underground gas drainage (primarily methane, CH4), real-time concentration monitoring is essential to prevent gas accumulation and potential explosions. Real-time gas concentration monitoring is vital for preventing gas explosions and ensuring miner safety. Gas monitoring devices are primarily based on optical, electrochemical, or catalytic combustion principles to detect the concentration of harmful gases such as methane. Traditional gas monitoring systems typically include sensor units, signal processing units, and alarm units, using a sensor network deployed underground to monitor gas concentration. With technological advancements, modern systems have incorporated wireless transmission, data analysis, and intelligent early warning capabilities.

[0003] Commonly used monitoring technologies include infrared absorption sensors, which work by utilizing the characteristic of methane to absorb specific infrared wavelengths and calculating its concentration through changes in light intensity. Their advantages include high accuracy, strong anti-interference capabilities, and long lifespan, especially in dark environments where accuracy is even higher.

[0004] In UDFFD (Directional Hydraulic Fracturing Enhanced Gas Extraction) gas control technology, monitoring boreholes are mainly used to monitor stress changes in the coal seam in real time during fracturing. After fracturing, they are connected to the extraction system or gas concentration monitoring system. The size of the monitoring borehole needs to balance monitoring accuracy and subsequent extraction requirements; the borehole diameter is 75-113 mm, and the depth is the same as or slightly deeper than the fracturing borehole. To prevent collapse of the monitoring borehole's inner wall, a casing is often installed inside the borehole after drilling. An abnormal gas outburst refers to the uncontrolled release of gas from the coal seam within a short period (minutes to hours), with a sudden increase in concentration or flow rate exceeding three times. In this case, power should be immediately cut off and personnel evacuated. In existing technologies, gas concentration monitoring mostly involves installing CH4 sensors (infrared or catalytic combustion type) at the orifice of the monitoring hole or near the orifice of the extraction pipe. Studies have found that this method also has the problem of delayed early warning, especially in cases of deep gas anomalies (such as precursors to outbursts). Based on the principle that an earlier warning means a longer safer evacuation, this invention discloses a real-time monitoring and early warning device for underground gas extraction concentration in coal mines. Summary of the Invention

[0005] In view of the above problems, the present invention provides a real-time monitoring and early warning device for gas concentration in underground coal mines. It can monitor and warn of gas concentration at depth in the monitoring hole, and can detect deep gas anomalies 10-30 minutes in advance, thus improving the safety of power outage and evacuation.

[0006] The specific technical solution is as follows:

[0007] A real-time monitoring and early warning device for methane extraction in coal mines includes an outer shell located deep within a casing. A deep concentration monitoring component is located at one end of the outer shell near the depth of a monitoring hole. The deep concentration monitoring component includes an infrared absorption sensor. A sealing and tightening component for connection to the inner wall of the casing is also located in the middle of the outer shell. The sealing and tightening component includes a sealing assembly for sealing the gap between the outer wall of the outer shell and the inner wall of the casing, and a tightening assembly for connecting the outer shell to the inner wall of the casing. The sealing assembly includes an inflatable annular airbag coaxially mounted on the outer wall of the outer shell. The tightening assembly includes a hydraulic cylinder perpendicular to the axis of the outer shell and a hydraulic system located inside the outer shell. A first piston block and a second piston block are fitted inside the hydraulic cylinder, forming a hydraulic cavity. A tightening rod is located on the end face of the first piston block away from the hydraulic cavity. The other end of the tightening rod passes through the side of the outer shell and is used to press against the inner wall of the casing. A pressure sensor is located between the end of the second piston block away from the hydraulic cavity and the bottom of the hydraulic cylinder. The hydraulic system is connected to the interior of the hydraulic cavity.

[0008] Furthermore, the outer shell is capsule-shaped, and a partition is coaxially arranged inside the outer shell. A concentration monitoring cavity is formed between the front end face of the partition and the inner wall of the outer shell, and a sealing and tightening cavity is formed between the rear end face of the partition and the inner wall of the outer shell. The deep concentration monitoring component is located inside the concentration monitoring cavity, and the sealing and tightening component is located at the sealing and tightening cavity. A monitoring window communicating with the inside of the concentration monitoring cavity is coaxially provided on the front end face of the outer shell. The detection end of the infrared absorption sensor is located at the monitoring window. A self-cleaning mirror for sealing and reducing coal ash pollution is also provided on the inner ring of the monitoring window, and a nano-coal-repellent coating is provided on the outer surface of the self-cleaning mirror.

[0009] Furthermore, a first breathable filter screen is provided on the partition, and a second breathable filter screen is provided at the tail end of the outer shell.

[0010] Furthermore, the deep concentration monitoring component also includes an ultrasonic vibrator located inside the concentration monitoring cavity for intermittently vibrating to clean coal ash from the outer surface of the nano-coal coating.

[0011] Furthermore, the deep concentration monitoring component also includes an air-blowing cleaning assembly, which includes an air-blowing head located on the outer front side of the housing for blowing air onto the outer surface of the nano-coal coating and a first air pump located inside the concentration monitoring chamber for delivering intermittent high-pressure gas to the air-blowing head. The first air pump is an intermittent high-pressure air pump.

[0012] Furthermore, the deep concentration monitoring component also includes a constant temperature heating assembly, which includes a heating element disposed inside the concentration monitoring chamber, a first temperature sensor for detecting the temperature inside the concentration monitoring chamber, and a second temperature sensor for detecting the temperature outside the concentration monitoring chamber.

[0013] Furthermore, the outer side of the outer shell is coaxially provided with an annular receiving groove at the location of the sealing and tightening cavity, and the inner ring of the annular airbag is provided with an annular seat for connecting with the bottom of the annular receiving groove. The sealing assembly also includes a second air pump located inside the sealing and tightening cavity. The air outlet of the second air pump is connected to the inside of the annular airbag through a second air supply pipe. A first air valve and an air pressure sensor are provided on the second air supply pipe.

[0014] Furthermore, each of the tightening rods is provided with a friction block at its outer end, and the end face of the friction block away from the tightening rod is an arc-shaped surface coaxial with the inner wall of the sleeve.

[0015] Furthermore, each set of clamping components includes several hydraulic cylinders, which are arranged sequentially at equal angles around the axis of the outer casing. Preferably, there are four cylinders, with an included angle of ninety degrees between adjacent cylinders.

[0016] Furthermore, the hydraulic system includes a hydraulic pump and a hydraulic oil tank located inside the sealed clamping cavity. The output end of the hydraulic pump is connected to a hydraulic main pipe. The hydraulic main pipe is provided with a plurality of hydraulic branch pipes that are connected to each hydraulic cavity one by one. Each hydraulic branch pipe is provided with a hydraulic valve.

[0017] Furthermore, the clamping assembly is provided in two sets, with the two sets of clamping assemblies respectively located at the front and rear ends of the sealing clamping cavity.

[0018] Furthermore, a power supply module, including a storage battery, is also provided inside the sealed clamping cavity.

[0019] Furthermore, a controller module is also provided inside the sealing and tightening cavity.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The present invention provides a real-time monitoring and early warning device for gas extraction concentration in coal mines. By setting a pressure-resistant protective shell in the deep part of the casing and setting a deep concentration monitoring component in the shell near the deep part of the monitoring hole, the device utilizes the characteristic of methane absorbing specific infrared wavelengths to set an infrared absorption sensor to emit infrared light of a specific wavelength. The concentration is calculated by the change in light intensity, thereby realizing the monitoring of the deep gas concentration in the extraction area. Compared with the prior art, it can detect deep gas anomalies 10-30 minutes in advance, which improves the safety of power outage and evacuation. The device also features a self-cleaning mirror, ultrasonic cleaning, air blowing cleaning, and constant temperature heating structure to improve the monitoring accuracy.

[0022] (2) The present invention provides a real-time monitoring and early warning device for gas extraction concentration in coal mines. By setting a sealing component for sealing the gap between the outer wall of the outer shell and the inner wall of the casing and a tightening component for connecting the outer shell and the inner wall of the casing, the gas at the extraction depth is prevented from overflowing from the casing, thereby further ensuring the accuracy of concentration monitoring and the stability of the monitoring equipment during operation.

[0023] (3) The present invention provides a real-time monitoring and early warning device for underground gas extraction in coal mines. By setting up a LoRa transmission module and a vibration energy conversion component, the data transmission between the deep concentration monitoring component and the external gas concentration monitoring and early warning terminal is realized. The vibration energy conversion component can convert the vibration during coal mining into electrical energy to power the equipment for continuous operation, thus solving the problem of difficult wiring due to the deep depth of the monitoring hole. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the outer casing of the present invention located deep within the monitoring hole.

[0025] Figure 2 This is a schematic diagram of the structure of the present invention.

[0026] Figure 3 This is a schematic diagram of the deep concentration monitoring component of the present invention.

[0027] Figure 4 This is a schematic diagram of the sealing and tightening component structure of the present invention.

[0028] Figure 5 This is the present invention. Figure 4 A magnified view of part A.

[0029] Figure 6 This is the present invention. Figure 4 Schematic diagram of cross-section at BB.

[0030] Figure 7 This is a schematic diagram of the vibration energy conversion component of the present invention.

[0031] Figure 8This is a schematic diagram of the vibration energy conversion component of the present invention from another angle.

[0032] Figure 9 This is a schematic diagram of the limiting guide groove structure of the present invention.

[0033] Figure 10 This is a schematic diagram of the two-stage lever amplification mechanism of the present invention.

[0034] Figure 11 This is a schematic diagram of the piezoelectric conversion component structure of the present invention.

[0035] In the diagram: 1. Monitoring port; 2. Sleeve; 3. Outer shell; 31. Partition; 32. Concentration monitoring chamber; 33. Sealed and tightened chamber; 34. Monitoring window; 35. Self-cleaning mirror; 36. First breathable filter; 37. Second breathable filter; 4. Deep concentration monitoring component; 41. Infrared absorption sensor; 42. Ultrasonic vibrator; 43. Air blowing cleaning component; 44. Constant temperature heating component; 441. Heating element; 442. First temperature sensor; 443. Second temperature sensor; 5. Sealed and tightened component; 6. Sealing component; 61. Annular storage groove; 62. Annular airbag; 63. Second air pump; 64. Second air supply pipe; 7. Tightening component; 71. Hydraulic cylinder; 72. First piston block; 73. Second piston block; 74. Hydraulic chamber; 75. Tightening rod; 76. Pressure sensor; 77. Hydraulic branch pipe; 78. Hydraulic main pipe; 79. 710. Hydraulic pump; 711. Hydraulic oil tank; 712. Hydraulic valve; 713. Friction block; 8. Power supply module; 9. Vibration energy conversion component; 91. Vibration energy acquisition component; 914. Mass block; 915. Limiting guide groove; 916. Arc-shaped side plate; 917. Arc-shaped top plate; 918. Arc-shaped bottom plate; 919. First arc-shaped opening; 910. Second arc-shaped opening; 911. Spring; 912. Swing rod ; 915, First universal joint; 92, Two-stage lever amplification mechanism; 921, First-stage lever; 922, Second-stage lever; 923, Push rod; 924, Second universal joint; 93, Piezoelectric conversion component; 931, Housing; 932, Corrugated groove; 933, Piezoelectric sheet; 934, Sliding column; 935, Extrusion ball head; 936, Reciprocating rod; 937, Hinge joint; 10, LoRa transparent transmission module; 11, Controller module. Detailed Implementation

[0036] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0037] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] Example 1

[0039] This invention provides a real-time monitoring and early warning device for methane concentration in underground coal mines, with reference to... Figure 1 , Figure 2 and Figure 3 The system includes an outer shell 3 located deep within the casing 2, which is situated inside the monitoring borehole 1. A deep concentration monitoring component 4, comprising an infrared absorption sensor 41, is located at one end of the outer shell 3 near the depth of the monitoring borehole 1. The outer shell 3 is made of titanium alloy, with a pressure resistance of 10 MPa. It is positioned 3-5 meters from the bottom of the borehole to avoid the area of ​​maximum stress (preventing cracking damage) while still monitoring the original coal seam gas. The infrared absorption sensor 41 uses a mining-grade infrared sensor (such as Ex ib I Mb), such as GJG100H, which has strong anti-interference capabilities and is unaffected by interfering gases such as CO2 and H2S. Its optical principle involves no chemical consumption, and its theoretical lifespan can reach more than 5 years. It can measure CH4 concentration from 0-100% with an accuracy of ±0.1%, making it suitable for monitoring high-concentration extraction wells. The infrared absorption sensor 41 contains a small bulb (infrared LED) to emit infrared light of a specific wavelength (such as 3.3μm or 4.2μm). In the dark environment deep within the monitoring well 1, there is no ambient light interference, resulting in more accurate detection. The infrared absorption sensor 41 utilizes the characteristic of methane absorbing specific infrared wavelengths, calculating the concentration through changes in light intensity to monitor the concentration of gas in deep extraction areas. Compared to existing technologies, it can detect deep gas anomalies 10-30 minutes earlier, improving the safety of power outages and evacuation.

[0040] refer to Figure 2 and Figure 3 The outer shell 3 is capsule-shaped, with a partition 31 coaxially arranged inside. A concentration monitoring cavity 32 is formed between the front end of the partition 31 and the inner wall of the outer shell 3, and a sealing and tightening cavity 33 is formed between the rear end of the partition 31 and the inner wall of the outer shell 3. A deep concentration monitoring component 4 is located inside the concentration monitoring cavity 32, and a sealing and tightening component 5 is located at the sealing and tightening cavity 33. A monitoring window 34, communicating with the inside of the concentration monitoring cavity 32, is coaxially arranged on the front end of the outer shell 3. The detection end of the infrared absorption sensor 41 is located at the monitoring window 34. A self-cleaning mirror 35 for sealing and reducing coal ash contamination is also provided within the monitoring window 34. The outer surface of the self-cleaning mirror 35 is provided with a nano-coal-repellent coating. A first breathable filter 36 is provided on the partition 31, and a second breathable filter 37 is provided at the rear end of the outer shell 3. The self-cleaning mirror 35 can reduce the possibility of deep coal ash adhering to the outer surface of the self-cleaning mirror 35, improving the monitoring accuracy of the infrared absorption sensor 41.

[0041] Furthermore, as a specific implementation method, refer to Figure 2 and Figure 3 The deep concentration monitoring component 4 also includes an ultrasonic vibrator 42 disposed inside the concentration monitoring chamber 32 for intermittently vibrating and cleaning coal ash from the outer surface of the nano-coal coating. The ultrasonic vibrator 42 vibrates once per minute, with each vibration lasting 2-5 seconds. The operation of the ultrasonic vibrator 42 can shake off the coal ash adhering to the outer surface of the nano-coal coating, further improving the monitoring accuracy of the infrared absorption sensor 41.

[0042] Furthermore, as a specific implementation method, refer to Figure 2 and Figure 3 The deep concentration monitoring component 4 further includes an air-blowing cleaning assembly 43. The air-blowing cleaning assembly 43 includes an air-blowing head located on the outer front end of the housing 3 for blowing air onto the outer surface of the nano-coal coating, and a first air pump located inside the concentration monitoring chamber 32 for delivering intermittent high-pressure gas to the air-blowing head. The first air pump is an intermittent high-pressure air pump. The first air pump operates once per hour, 3-5 times each time, cleaning the outer surface of the nano-coal coating by intermittently spraying high-pressure gas, further improving the monitoring accuracy of the infrared absorption sensor 41.

[0043] Furthermore, as a specific implementation method, refer to Figure 2 and Figure 3 The deep concentration monitoring component 4 further includes a constant temperature heating assembly 44, which includes a heating element 441 disposed inside the concentration monitoring chamber 32, a first temperature sensor 442 for detecting the internal temperature of the concentration monitoring chamber 32, and a second temperature sensor 443 for detecting the external temperature of the concentration monitoring chamber 32. The operation of the heating element 441 maintains the operating temperature of the infrared absorption sensor 41 4-6°C higher than the external environment of the housing 3, further improving the monitoring accuracy of the infrared absorption sensor 41.

[0044] refer to Figure 2 , Figure 4 , Figure 5 and Figure 6The sealing and tightening component 5 includes a sealing assembly 6 for sealing the gap between the outer wall of the outer shell 3 and the inner wall of the sleeve 2, and a tightening assembly 7 for connecting the outer shell 3 and the inner wall of the sleeve 2. The sealing assembly 6 includes an inflatable annular airbag 62 coaxially mounted on the outer wall of the outer shell 3. The tightening assembly 7 includes a hydraulic cylinder 71 perpendicular to the axis of the outer shell 3 and a hydraulic system located inside the outer shell 3. A first piston block 72 and a second piston block 73 are adapted inside the hydraulic cylinder 71, forming a hydraulic cavity 74 between the first piston block 72 and the second piston block 73. A tightening rod 75 is provided on the end face of the first piston block 72 away from the hydraulic cavity 74, and the other end of the tightening rod 75 passes through the side of the outer shell 3 and is used to connect with the sleeve. The inner wall of the sleeve 2 is tightly fitted. A pressure sensor 76 is provided between the end of the second piston block 73 away from the hydraulic chamber 74 and the bottom of the hydraulic cylinder 71. The hydraulic system is connected to the inside of the hydraulic chamber 74. Each set of clamping components 7 is provided with several hydraulic cylinders 71. The several hydraulic cylinders 71 are arranged sequentially at equal angles around the axis of the outer shell 3, preferably four, and the included angle between adjacent hydraulic cylinders 71 is ninety degrees. The hydraulic system includes a hydraulic pump 79 and a hydraulic oil tank 710 located inside the sealed clamping chamber 33. The output end of the hydraulic pump 79 is connected to a hydraulic main pipe 78. Several hydraulic branch pipes 77 are provided on the hydraulic main pipe 78, which are connected to each hydraulic chamber 74 one by one. Each hydraulic branch pipe 77 is provided with a hydraulic valve 711. A friction block 712 is provided at the outer end of each clamping rod 75. The end face of the friction block 712 away from the clamping rod 75 is an arc-shaped surface coaxial with the inner wall of the sleeve 2. After the outer casing 3 reaches the predetermined position inside the casing 2, the operation of the hydraulic pump 79 causes each clamping rod 75 to extend out of the outer casing 3 and the friction block 712 to press tightly against the inner wall of the casing 2. Each pressure sensor 76 is used to detect the clamping force of the corresponding clamping rod 75, ensuring that the clamping force of each clamping rod 75 tends to be the same and reaches a preset threshold, thus realizing the connection between the outer casing 3 and the casing 2. Afterwards, each hydraulic valve 711 is in the closed state. During long-term monitoring, the friction block 712 will inevitably wear due to mining vibration. When the corresponding pressure sensor 76 detects that the clamping force is less than the preset threshold, it controls the corresponding hydraulic valve 711 to open. The operation of the hydraulic pump 79 compensates for the clamping force of the clamping rod 75, so that each clamping rod 75 always maintains a certain clamping force, ensuring the stability of the connection between the outer casing 3 and the casing 2, and further improving the monitoring accuracy of the infrared absorption sensor 41.

[0045] Furthermore, as a specific implementation method, refer to Figure 4 and Figure 5The outer surface of the outer shell 3 is coaxially provided with an annular receiving groove 61 at the location of the sealing and tightening cavity 33. The inner ring of the annular airbag 62 is provided with an annular seat for connecting with the bottom of the annular receiving groove 61. The sealing assembly 6 also includes a second air pump 63 located inside the sealing and tightening cavity 33. The air outlet of the second air pump 63 is connected to the inside of the annular airbag 62 through a second air supply pipe 64. The second air supply pipe 64 is provided with a first air valve and a pressure sensor. The annular receiving groove 61 can store the annular airbag 62 when the outer shell 3 is put in or taken out, so as to avoid the annular airbag 62 affecting the insertion of the outer shell 3. After each tightening rod 75 is tightened, the operation of the second air pump 63 can cause the annular airbag 62 to expand, so that the outer surface of the annular airbag 62 is tightly attached to the inner wall of the sleeve 2. When the air pressure detected by the pressure sensor reaches a preset threshold, the first air valve closes and the second air pump 63 stops working.

[0046] Furthermore, as a specific implementation method, refer to Figure 2 The clamping assembly 7 is provided in two sets, and the two sets of clamping assemblies 7 are respectively located at the front and rear ends of the sealing clamping cavity 33.

[0047] Furthermore, as a specific implementation method, refer to Figure 4 The sealed clamping cavity 33 also houses a power supply module 8, which includes a battery; the sealed clamping cavity 33 also houses a controller module 11. The battery is a lithium battery pack.

[0048] Furthermore, as one implementation method, refer to Figure 4 The rear end of the outer casing 3 is also provided with a traction ring, and the traction ring is provided with a traction rope for removing the outer casing 3 from inside the sleeve 2.

[0049] Furthermore, as one implementation, the rear end of the outer casing 3 is also provided with a cable for charging the power supply module 8 and an optical fiber network cable for data transmission with the controller module 11. The other ends of the traction rope, cable, and optical fiber network cable all extend to the outside of the monitoring hole 1. The cable is connected to an external power source, and the optical fiber network cable is connected to an external gas concentration monitoring and early warning terminal. The gas concentration monitoring and early warning terminal can obtain the gas concentration deep in the monitoring hole 1 in real time and issue an alarm when it exceeds a preset threshold.

[0050] Example 2

[0051] According to the working principle of Embodiment 1, the data transmission between the deep concentration monitoring component 4 and the external gas concentration monitoring and early warning terminal mainly relies on optical fiber network cable. However, when the optical fiber network cable is laid inside the monitoring hole 1, it becomes difficult to lay the cable after a certain length. For the monitoring of gas concentration in some deeper monitoring holes 1, this embodiment adopts a wireless method to realize the communication between the controller module 11 and the external gas concentration monitoring and early warning terminal. However, with the wireless method, the charging problem of the power supply module 8 inside the outer shell 3 needs to be solved. In addition, during coal mining, the operation of underground equipment (such as drilling rigs and coal mining machines) and blasting will generate a certain amount of vibration.

[0052] This invention provides a real-time monitoring and early warning device for gas extraction concentration in coal mines, based on Example 1 and with reference to... Figure 1 and Figure 7 The sealed clamping cavity 33 is also equipped with a LoRa transmission module 10 and a vibration energy conversion component 9. The vibration energy conversion component 9 includes a vibration energy acquisition component 91, a two-stage lever amplification mechanism 92, and a piezoelectric conversion component 93. The vibration energy acquisition component 91 includes a mass block 911 that oscillates inertially along a predetermined trajectory when subjected to mining stress fluctuations. The two-stage lever amplification mechanism 92 includes a first-stage lever 921 and a second-stage lever 922 that amplify the displacement of the mass block 911. The piezoelectric conversion component 93 includes a piezoelectric element 933 that converts the amplified displacement of the mass block 911 into electrical energy. When the monitoring hole 1 is subjected to mining stress fluctuations (0.5-10Hz low-frequency vibration), the vibration is transmitted to the casing 2. The clamping rod 75 provides a rigid connection between the outer shell 3 and the casing 2, transmitting the vibration to the outer shell 3. The vibration of the outer shell 3 causes the suspended mass block 911 to oscillate. By setting up the LoRa transparent transmission module 10 and the vibration energy conversion component 9, data transmission between the deep concentration monitoring component 4 and the external gas concentration monitoring and early warning terminal is realized. The vibration energy conversion component 9 can convert the vibration during coal mining into electrical energy to power the equipment for continuous operation, thus solving the problem of difficult wiring due to the deep depth of the monitoring hole 1.

[0053] Furthermore, as a specific implementation method, refer to Figure 7 , Figure 8 and Figure 9The vibration energy acquisition component 91 further includes a limiting guide groove 912, which includes two coaxially arranged arc-shaped side plates 9121. An arc-shaped top plate 9122 is provided at the upper end of the two arc-shaped side plates 9121, and an arc-shaped bottom plate 9123 is provided at the lower end of the two arc-shaped side plates 9121. The two arc-shaped side plates 9121, the arc-shaped top plate 9122, and the arc-shaped bottom plate 9123 form an arc-shaped guide groove that allows the mass block 911 to move along a predetermined trajectory. The arc-shaped top plate 9122 and the arc-shaped bottom plate 9123 are both inclined at a certain angle, with an inclination angle of 15-25 degrees. Two arc-shaped side plates 9121 are located on the front and rear sides of the mass block 911, respectively. The vibration force in the front-back direction of the monitoring hole 1 can be converted into a force in the predetermined trajectory direction of the mass block 911. The vibration force in the left-right direction of the monitoring hole 1 can also be converted into a force in the predetermined trajectory direction of the mass block 911. The arc-shaped top plate 9122 and the arc-shaped bottom plate 9123 are set at a certain angle, which can also convert the vibration force in the up-down direction of the monitoring hole 1 into a force in the predetermined trajectory direction of the mass block 911. No matter which direction the vibration force is, it can ultimately be converted into a force in the predetermined trajectory direction of the mass block 911, thus avoiding the random shaking of the mass block 911. A first arc-shaped opening 9124 is coaxially arranged on the arc-shaped top plate 9122. A spring 913 is provided at the upper end of the mass block 911. The upper end of the spring 913 is suspended from the upper part of the inner shell 3 through the first arc-shaped opening 9124. A second arc-shaped opening 9125 is coaxially arranged on the arc-shaped bottom plate 9123. A swing rod 914 is provided at the lower end of the mass block 911. The lower end of the swing rod 914 is hinged to a first universal joint 915 after passing through the second arc-shaped opening 9125. The mass block 911 is a tungsten alloy eccentric mass block 911, spherical in shape, with a density of 18.5 g / cm³. 3 The mass block 911, measuring Φ30×15mm, is suspended from a titanium alloy spring 913 with a stiffness coefficient of 5N / m and is corrosion-resistant. When the borehole experiences mining stress fluctuations (0.5~10Hz), the mass block 911 generates inertial oscillation, which is converted into unidirectional impact through the limiting guide groove 912, improving energy utilization by 40%. The limiting guide groove 912 transforms vibrations in all directions (up and down, left and right, forward and backward) in the borehole into a unidirectional impact force, allowing the piezoelectric element 933 to generate electricity efficiently. The limiting guide groove 912 is made of stainless steel or titanium alloy, providing rust resistance and impact resistance. The conversion efficiency is higher when the arc-shaped top plate 9122 and arc-shaped bottom plate 9123 are tilted at a 15° angle. The track width is 0.5-1mm larger than the diameter of the mass block 911 to prevent jamming, and the inner wall is coated with graphite.

[0054] Furthermore, as a specific implementation method, refer to Figure 7 , Figure 8 and Figure 10The short arm of the first-stage lever 921 is hinged to the first universal joint 915, and the long arm of the first-stage lever 921 is hinged to a push rod 923 via a second universal joint 924. The other end of the push rod 923 is hinged to the short arm of the second-stage lever 922 via another second universal joint 924. The first-stage lever 921 has a magnification ratio of 3:1, is made of stainless steel, and uses a self-lubricating bearing at the hinge point. The short arm is connected to a mass block 911, and the long arm transmits motion through the titanium alloy push rod 923. The second-stage lever 922 has a magnification ratio of 2:1, is made of carbon fiber composite material, and has a polytetrafluoroethylene (PTFE) buffer pad at the end to reduce noise. The vibration amplification mechanism is the core component for improving the piezoelectric energy harvesting efficiency. It can output a displacement of 0.5-0.6 mm from a vibration of 0.1 mm. The second universal joint 924 can avoid lateral force interference.

[0055] Furthermore, as a specific implementation method, refer to Figure 7 , Figure 8 and Figure 11 The piezoelectric conversion component 93 further includes a housing 931, which is horizontally arranged in the left-right direction along its length. A corrugated groove 932 is formed along the length of the middle of the upper and lower inner walls of the housing 931. A sliding column 934 is adapted within the corrugated groove 932. Piezoelectric sheets 933 are respectively arranged on the front and rear sides of the corrugated groove 932 inside the housing 931. Extrusion ball heads 935 for pressing the piezoelectric sheets 933 are respectively provided at the front and rear ends of the sliding column 934. A reciprocating rod 936 is hinged to the side of the sliding column 934 near the secondary lever 922. The other end of the reciprocating rod 936 passes through the housing 931 and is connected to the long arm end of the secondary lever 922 via a hinge joint 937. The piezoelectric sheet 933 is made of flexible piezoelectric film (PVDF-TrFE) to improve vibration energy collection efficiency. Self-powered operation is achieved at the depth of monitoring hole 1 using a vibration scheme and ultra-low power sensing technology. Application is recommended for holes deeper than 200m or in hazardous areas. Four sets of piezoelectric elements 933, each 20×10×0.5mm in size, are connected in series to superimpose their output voltages. When the long arm of the secondary lever 922 swings, it moves the reciprocating rod 936, which in turn moves the sliding column 934 within the corrugated groove 932. This, in turn, moves the compression ball head 935, compressing the piezoelectric elements 933, thereby generating electrical energy that is stored in the battery.

[0056] The infrared absorption sensor 41 adopts an intermittent working mode, waking up for 10 seconds every minute, saving power while ensuring monitoring.

[0057] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The embodiments described above are merely illustrative of implementation methods of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A real-time monitoring and early warning device for methane concentration in underground coal mines, characterized in that, The device includes an outer shell located deep within a casing. A deep concentration monitoring component is located within the outer shell near the depth of the monitoring port. The deep concentration monitoring component includes an infrared absorption sensor. A sealing and tightening component for connection to the inner wall of the casing is located in the middle of the outer shell. The sealing and tightening component includes a sealing assembly for sealing the gap between the outer wall of the outer shell and the inner wall of the casing, and a tightening assembly for connecting the outer shell to the inner wall of the casing. The sealing assembly includes an inflatable annular airbag coaxially mounted on the outer wall of the outer shell. The tightening assembly includes a hydraulic cylinder perpendicular to the axis of the outer shell and a hydraulic system located inside the outer shell. A first piston block and a second piston block are fitted inside the hydraulic cylinder, forming a hydraulic cavity. A tightening rod is located on the end face of the first piston block away from the hydraulic cavity. The other end of the tightening rod passes through the side of the outer shell and is used to press against the inner wall of the casing. A pressure sensor is located between the end of the second piston block away from the hydraulic cavity and the bottom of the hydraulic cylinder. The hydraulic system is connected to the interior of the hydraulic cavity. The sealed clamping cavity is also equipped with a LoRa transparent transmission module and a vibration energy conversion component. The vibration energy conversion component includes a vibration energy acquisition component, a two-stage lever amplification mechanism, and a piezoelectric conversion component. The vibration energy acquisition component includes a mass block that oscillates inertially when subjected to mining stress fluctuations. The vibration energy acquisition component also includes a limiting guide groove, which includes two coaxially arranged arc-shaped side plates. An arc-shaped top plate is provided at the upper end of the two arc-shaped side plates, and an arc-shaped bottom plate is provided at the lower end of the two arc-shaped side plates. The two arc-shaped side plates, the arc-shaped top plate, and the arc-shaped bottom plate form an arc-shaped guide groove that allows the mass block to move along a predetermined trajectory. The arc-shaped top plate and the arc-shaped bottom plate are both inclined at a certain angle, with an inclination angle of 15-25 degrees. The dual-stage lever amplification mechanism includes a primary lever and a secondary lever that amplify the displacement of the mass block; The short arm end of the first-stage lever is hinged to the first universal joint, and the long arm end of the first-stage lever is hinged to a push rod via a second universal joint. The other end of the push rod is hinged to the short arm end of the second-stage lever via another second universal joint. The piezoelectric conversion component includes a piezoelectric element that converts the amplified displacement into electrical energy and powers the device. The piezoelectric conversion assembly also includes a housing, which is horizontally arranged in the left-right direction along its length. A corrugated groove is provided in the middle of the upper and lower inner walls of the housing along its length. A sliding column is adapted in the corrugated groove. Piezoelectric pieces are respectively arranged on the front and rear sides of the corrugated groove inside the housing. Extrusion ball heads for pressing the piezoelectric pieces are respectively provided at the front and rear ends of the sliding column. A reciprocating rod is hinged to the side of the sliding column near the secondary lever. The other end of the reciprocating rod passes through the housing and is connected to the end of the long arm of the secondary lever through a hinge joint.

2. The real-time monitoring and early warning device for underground gas extraction in coal mines according to claim 1, characterized in that, The outer shell is capsule-shaped, and a partition is coaxially arranged inside the outer shell. A concentration monitoring cavity is formed between the front end face of the partition and the inner wall of the outer shell, and a sealing and tightening cavity is formed between the rear end face of the partition and the inner wall of the outer shell. The deep concentration monitoring component is located inside the concentration monitoring cavity, and the sealing and tightening component is located at the sealing and tightening cavity. A monitoring window communicating with the inside of the concentration monitoring cavity is coaxially provided on the front end face of the outer shell. The detection end of the infrared absorption sensor is located at the monitoring window. A self-cleaning mirror for sealing and reducing coal ash pollution is also provided on the inner ring of the monitoring window. A nano-coal-repellent coating is provided on the outer surface of the self-cleaning mirror.

3. The real-time monitoring and early warning device for underground gas extraction in coal mines according to claim 2, characterized in that, The deep concentration monitoring component also includes an ultrasonic vibrator located inside the concentration monitoring cavity for intermittently vibrating to clean coal ash from the outer surface of the nano-coal coating.

4. The real-time monitoring and early warning device for underground gas extraction in coal mines according to claim 3, characterized in that, The deep concentration monitoring component also includes an air-blowing cleaning assembly, which includes an air-blowing head located on the outer front side of the housing for blowing air onto the outer surface of the nano-coal coating and a first air pump located inside the concentration monitoring chamber for delivering intermittent high-pressure gas to the air-blowing head. The first air pump is an intermittent high-pressure air pump.

5. The real-time monitoring and early warning device for underground gas extraction in coal mines according to claim 1, characterized in that, The deep concentration monitoring component also includes a constant temperature heating assembly, which includes a heating element disposed inside the concentration monitoring chamber, a first temperature sensor for detecting the temperature inside the concentration monitoring chamber, and a second temperature sensor for detecting the temperature outside the concentration monitoring chamber.

6. The real-time monitoring and early warning device for underground gas extraction in coal mines according to claim 2, characterized in that, The outer side of the outer shell is coaxially provided with an annular storage groove at the location of the sealing and tightening cavity. The inner ring of the annular airbag is provided with an annular seat for connecting with the bottom of the annular storage groove. The sealing assembly also includes a second air pump located inside the sealing and tightening cavity. The air outlet of the second air pump is connected to the inside of the annular airbag through a second air supply pipe. A first air valve and an air pressure sensor are provided on the second air supply pipe.

7. The real-time monitoring and early warning device for underground gas extraction in coal mines according to claim 2, characterized in that, Each set of clamping components is provided with a number of hydraulic cylinders, which are arranged sequentially at equal angles around the axis of the outer shell.

8. The real-time monitoring and early warning device for underground gas extraction in coal mines according to claim 7, characterized in that, The hydraulic system includes a hydraulic pump and a hydraulic oil tank located inside the sealed clamping cavity. The output end of the hydraulic pump is connected to a hydraulic main pipe. The hydraulic main pipe is provided with several hydraulic branch pipes that are connected to each hydraulic cavity one by one. Each hydraulic branch pipe is provided with a hydraulic valve.

9. The real-time monitoring and early warning device for underground gas extraction in coal mines according to claim 8, characterized in that, The tightening assembly is provided in two sets, and the two sets of tightening assemblies are respectively located at the front and rear ends of the sealing tightening cavity.

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