Concentration real-time monitoring and early warning device for coal mine underground gas extraction

Abstract

The invention relates to a coal mine underground gas extraction concentration real-time monitoring and early warning device which comprises a shell arranged in the deep part of a sleeve, a deep part concentration monitoring part is arranged at one end, close to the deep part of a monitoring hole, in the shell, and the deep part concentration monitoring part comprises an infrared absorption type sensor. And a sealing jacking part connected with the inner wall of the sleeve is also arranged in the middle of the shell. According to the invention, gas concentration monitoring and early warning can be carried out at the deep part of the monitoring hole, deep gas abnormity can be found 10-30 minutes in advance, and a guarantee is provided for safe power-off and people removal.

Description

Technical Field

[0001] The present invention relates to the technical field of gas concentration monitoring equipment, and in particular, to a device for real-time monitoring and early warning of the concentration of gas extracted from coal mines underground. Background Art

[0002] Gas extraction is an important link in the safe production of coal mines. When extracting gas (the main component is methane, CH4) from coal mines underground, it is necessary to monitor the concentration in real time to prevent gas accumulation from causing an explosion. Real-time monitoring of gas concentration is crucial for preventing gas explosions and ensuring the safety of miners. Gas monitoring devices are mainly based on principles such as optics, electrochemistry, or catalytic combustion, and are used to detect the concentration of harmful gases such as methane. Traditional gas monitoring systems usually include a sensor unit, a signal processing unit, and an alarm unit, and realize gas concentration monitoring through a sensor network arranged underground. With the progress of technology, modern systems have added functions such as wireless transmission, data analysis, and intelligent early warning.

[0003] Among the commonly used monitoring technologies, there is an infrared absorption type sensor, whose principle is to utilize the characteristic that methane absorbs a specific infrared wavelength, and calculate the concentration through the change in light intensity. Its advantages include high accuracy, strong anti-interference ability, and long service life. Especially in a dark environment, the accuracy is higher.

[0004] In the UDFFD (Directional Hydraulic Fracturing Enhanced Extraction) gas control technology, monitoring holes are mainly used to monitor the stress change of the coal seam in real time during the fracturing process, and are connected to the gas extraction system or the gas concentration monitoring system after fracturing. The size of the monitoring holes needs to take into account both the monitoring accuracy and the later extraction requirements. The hole diameter is 75 - 113 mm, and the hole depth is the same as or slightly deeper than that of the fracturing hole. To prevent the inner wall of the monitoring hole from collapsing, a casing is usually set inside the monitoring hole after drilling. Abnormal gas outburst refers to the non-controlled release of gas in the coal seam within a short period (from a few minutes to a few hours), with the concentration or flow rate suddenly increasing by more than 3 times. At this time, power should be cut off immediately and workers should be evacuated. In the prior art, for the monitoring of gas concentration, a CH4 sensor (infrared or catalytic combustion type) is mostly installed at the orifice of the monitoring hole or near the orifice of the gas extraction pipe. It is found that this method still has the problem of delayed early warning. Especially in the case of deep gas anomalies (such as the precursor of outburst), in line with the principle that one more minute of early warning means one more minute of safe evacuation, the present invention discloses a device for real-time monitoring and early warning of the concentration of gas extracted from coal mines underground. Summary of the Invention

[0005] In view of the above problems, the present invention provides a device for real-time monitoring and early warning of the concentration of gas extracted from coal mines underground, which can monitor and give early warning of the gas concentration in the deep part of the monitoring hole, can detect deep gas anomalies 10 - 30 minutes in advance, and provides a guarantee for safe power cut-off and personnel evacuation.

[0006] The specific technical solution is as follows: A real-time monitoring and early warning device for the concentration of gas extraction in coal mines, including a housing located deep in the casing. At one end of the housing close to the deep part of the monitoring hole, a deep concentration monitoring component is provided. The deep concentration monitoring component includes an infrared absorption sensor. In the middle of the housing, a sealing and tightening component for connecting with the inner wall of the casing is also provided. The sealing and tightening component includes a sealing component for sealing the gap between the outer wall of the housing and the inner wall of the casing and a tightening component for connecting the housing with the inner wall of the casing. The sealing component includes an inflatable annular airbag coaxially arranged on the outer wall of the housing. The tightening component includes a hydraulic cylinder body perpendicular to the axis of the housing and a hydraulic system arranged inside the housing. A first piston block and a second piston block are fitted in the hydraulic cylinder body. A hydraulic chamber is formed between the first piston block and the second piston block. A tightening rod is arranged on the end face of the first piston block away from the hydraulic chamber. The other end of the tightening rod penetrates the side of the housing and is used to closely adhere to the inner wall of the casing. A pressure sensor is arranged between the end of the second piston block away from the hydraulic chamber and the bottom of the hydraulic cylinder body. The hydraulic system is communicated with the inside of the hydraulic chamber.

[0007] Further, the housing is in a capsule shape. A partition is coaxially arranged inside the housing. A concentration monitoring chamber is formed between the front end face of the partition and the inner wall of the housing. A sealing and tightening chamber is formed between the rear end face of the partition and the inner wall of the housing. The deep concentration monitoring component is arranged inside the concentration monitoring chamber. The sealing and tightening component is arranged at the sealing and tightening chamber. A monitoring window communicated with the inside of the concentration monitoring chamber is coaxially arranged on the front end face of the housing. The detection end of the infrared absorption sensor is located at the position of the monitoring window. A self-cleaning mirror for sealing and reducing coal ash pollution is also arranged inside the inner circle of the monitoring window. A nano-hydrophobic coal coating is arranged on the outer side of the self-cleaning mirror.

[0008] Further, a first breathable filter screen is arranged on the partition, and a second breathable filter screen is arranged at the tail end of the housing.

[0009] Further, the deep concentration monitoring component also includes an ultrasonic vibrator arranged inside the concentration monitoring chamber for intermittently vibrating and cleaning the coal ash on the outer surface of the nano-hydrophobic coal coating.

[0010] Further, the deep concentration monitoring component also includes a blowing cleaning component. The blowing cleaning component includes a blowing head arranged outside the front end of the housing for blowing air to the outer surface of the nano-hydrophobic coal coating and a first air pump arranged inside the concentration monitoring chamber for delivering intermittent high-pressure gas to the blowing head. The first air pump is an intermittent high-pressure air pump.

[0011] Further, the deep concentration monitoring component further includes a constant temperature heating component, which includes a heating element disposed inside the concentration monitoring cavity, a first temperature sensor for detecting the temperature inside the concentration monitoring cavity, and a second temperature sensor for detecting the temperature outside the concentration monitoring cavity.

[0012] Further, an annular storage groove is coaxially provided on the outer side surface of the outer shell at the position of the sealing and tightening cavity. An annular seat for connecting with the bottom of the annular storage groove is provided on the inner ring of the annular airbag. The sealing component further includes a second air pump disposed inside the sealing and tightening cavity. The air outlet end of the second air pump is communicated with the inside of the annular airbag through a second air pipe. A first air valve and a pressure sensor are provided on the second air pipe.

[0013] Further, friction blocks are respectively provided at the outer ends of each of the tightening rods. The end surface of the friction block away from the tightening rod is an arc surface coaxially arranged with the inner wall of the sleeve.

[0014] Further, a plurality of hydraulic cylinder bodies are provided in each set of the tightening assemblies. The plurality of hydraulic cylinder bodies are sequentially arranged at equal angles around the axis of the outer shell. Preferably, there are four, and the included angle between adjacent hydraulic cylinder bodies is ninety degrees.

[0015] Further, the hydraulic system includes a hydraulic pump and a hydraulic oil tank disposed inside the sealing and tightening cavity. The output end of the hydraulic pump is communicated with a main hydraulic pipe. A plurality of hydraulic branch pipes respectively communicated with each hydraulic cavity are provided on the main hydraulic pipe. Hydraulic valves are respectively provided on each of the hydraulic branch pipes.

[0016] Further, two sets of the tightening assemblies are provided, and the two sets of the tightening assemblies are respectively disposed at the front and rear ends of the sealing and tightening cavity.

[0017] Further, a power supply module including a storage battery is further provided inside the sealing and tightening cavity.

[0018] Further, a controller module is further provided inside the sealing and tightening cavity.

[0019] Compared with the prior art, the present invention has the following beneficial effects: (1)The real-time monitoring and early warning device for the concentration of gas extraction in coal mines of the present invention sets a compressive protection shell deep in the casing, and sets a deep concentration monitoring component at one end of the shell close to the deep part of the monitoring hole. Utilizing the characteristic that methane absorbs specific infrared wavelengths, an infrared absorption type sensor is set to emit infrared light of a specific wavelength, and the concentration is calculated through the change in light intensity, realizing the monitoring of the deep gas concentration in the extraction. Compared with the prior art, it can detect deep gas anomalies 10 - 30 minutes in advance, providing guarantee for safe power cut and personnel evacuation, and setting a self-cleaning mirror surface, ultrasonic cleaning, air blowing cleaning, and constant temperature heating structure to improve the monitoring accuracy.

[0020] (2)The real-time monitoring and early warning device for the concentration of gas extraction in coal mines of the present invention sets a sealing component for sealing the gap between the outer wall of the shell and the inner wall of the casing and a tightening component for connecting the shell and the inner wall of the casing, avoiding the overflow of gas at the extraction depth from the casing, and further ensuring the accuracy of concentration monitoring and the stability of the monitoring equipment during operation.

[0021] (3)The real-time monitoring and early warning device for the concentration of gas extraction in coal mines of the present invention sets a LoRa transparent transmission module and a vibration energy conversion component, realizing the data transmission between the deep concentration monitoring component and the external gas concentration monitoring and early warning terminal. The vibration energy conversion component can convert the vibration during coal mining into electric energy for the continuous operation of the equipment, solving the problem of difficult wiring due to the deep depth of the monitoring hole. Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the shell of the present invention when it is located deep in the monitoring hole.

[0023] Figure 2 It is a schematic structural diagram of the present invention.

[0024] Figure 3 It is a schematic structural diagram of the deep concentration monitoring component of the present invention.

[0025] Figure 4 It is a schematic structural diagram of the sealing and tightening component of the present invention.

[0026] Figure 5 It is the present invention Figure 4 Partial enlarged schematic diagram at A of.

[0027] Figure 6 It is the present invention Figure 4 Cross-sectional view at B - B of.

[0028] Figure 7 It is a schematic structural diagram of the vibration energy conversion component of the present invention.

[0029] Figure 8It is a schematic structural diagram of another angle of the vibration energy conversion component of the present invention.

[0030] Figure 9 It is a schematic structural diagram of the limit guide groove structure of the present invention.

[0031] Figure 10 It is a schematic structural diagram of the double-stage lever amplification mechanism of the present invention.

[0032] Figure 11 It is a schematic structural diagram of the piezoelectric conversion component of the present invention.

[0033] In the figure: 1. Monitoring hole; 2. Sleeve; 3. Outer shell; 31. Partition board; 32. Concentration monitoring chamber; 33. Sealing and tightening chamber; 34. Monitoring window; 35. Self-cleaning mirror; 36. First breathable filter screen; 37. Second breathable filter screen; 4. Deep concentration monitoring component; 41. Infrared absorption type sensor; 42. Ultrasonic vibrator; 43. Blowing type cleaning component; 44. Constant temperature heating component; 441. Heating element; 442. First temperature sensor; 443. Second temperature sensor; 5. Sealing and tightening component; 6. Sealing component; 61. Annular receiving groove; 62. Annular airbag; 63. Second air pump; 64. Second air delivery pipe; 7. Tightening component; 71. Hydraulic cylinder body; 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. Hydraulic pump; 710. Hydraulic oil tank; 711. Hydraulic valve; 712. Friction block; 8. Power supply module; 9. Vibration energy conversion component; 91. Vibration energy collection component; 911. Mass block; 912. Limit guide groove; 9121. Arc-shaped side plate; 9122. Arc-shaped top plate; 9123. Arc-shaped bottom plate; 9124. First arc-shaped opening; 9125. Second arc-shaped opening; 913. Spring; 914. Swing rod; 915. First universal joint; 92. Double-stage lever amplification mechanism; 921. First-stage lever; 922. Second-stage lever; 923. Push rod; 924. Second universal joint; 93. Piezoelectric conversion component; 931. Shell; 932. Corrugated chute; 933. Piezoelectric sheet; 934. Slide column; 935. Extrusion ball head; 936. Reciprocating rod; 937. Hinge joint; 10. LoRa transparent transmission module; 11. Controller module. Detailed implementation manners

[0034] The following further elaborates on the present application in conjunction with the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related invention and do not limit the invention. Additionally, it should be noted that for ease of description, only the parts related to the invention are shown in the drawings.

[0035] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following will detail the present application with reference to the accompanying drawings and in conjunction with the embodiments.

[0036] Embodiment 1 The present invention provides a real-time monitoring and early warning device for the concentration of gas extraction in coal mines. Referring to Figure 1 、 Figure 2 and Figure 3 , it includes a housing 3 arranged deep in a casing 2. The casing 2 is arranged in a monitoring hole 1. At one end of the housing 3 close to the deep part of the monitoring hole 1, there is a deep concentration monitoring component 4. The deep concentration monitoring component 4 includes an infrared absorption sensor 41. The housing 3 is made of a titanium alloy protective housing 3 with a compressive resistance of 10 Mpa. The housing 3 is arranged 3 - 5 m away from the bottom of the hole, avoiding the maximum stress area (to prevent fracturing damage), and can also monitor the gas in the original coal seam. The infrared absorption sensor 41 is a mine-used type (such as Ex ib I Mb) infrared sensor, such as GJG100H. It has strong anti-interference ability, is not affected by interference gases such as CO2 and H2S, has no chemical consumption in the optical principle, and the theoretical service life can reach more than 5 years. It can measure the CH4 concentration of 0 - 100%, with an accuracy of ±0.1%. It is suitable for monitoring high-concentration extraction holes. Inside the infrared absorption sensor 41, there is a small light bulb (infrared LED) for emitting infrared light of a specific wavelength (such as 3.3 μm or 4.2 μm). In the dark environment deep in the monitoring hole 1, there is no ambient light interference, and the detection is more accurate. The infrared absorption sensor 41 utilizes the characteristic that methane absorbs a specific infrared wavelength, calculates the concentration through the change in light intensity, and realizes the monitoring of the concentration of deep-extracted gas. Compared with the existing technology, it can detect deep gas anomalies 10 - 30 minutes in advance, providing guarantee for safe power-off and personnel evacuation.

[0037] Referring to Figure 2 and Figure 3 , the housing 3 is in a capsule shape. A partition 31 is coaxially arranged inside the housing 3. A concentration monitoring chamber 32 is formed between the front end face of the partition 31 and the inner wall of the housing 3. A sealing and pressing chamber 33 is formed between the rear end face of the partition 31 and the inner wall of the housing 3. The deep concentration monitoring component 4 is arranged inside the concentration monitoring chamber 32, and a sealing and pressing component 5 is arranged at the sealing and pressing chamber 33. A monitoring window 34 communicating with the inside of the concentration monitoring chamber 32 is coaxially arranged on the front end face of the housing 3. The detection end of the infrared absorption sensor 41 is located at the position of the monitoring window 34. An auto-cleaning mirror 35 for sealing and reducing coal ash pollution is also arranged inside the inner circle of the monitoring window 34. A nano-scale coal-repellent coating is arranged on the outer side of the auto-cleaning mirror 35. The auto-cleaning mirror 35 can reduce the possibility of coal ash in deep extraction adhering to the outer surface of the auto-cleaning mirror 35, and improve the monitoring accuracy of the infrared absorption sensor 41.

[0038] Furthermore, as a specific implementation manner, referring to Figure 2 and Figure 3 , the deep concentration monitoring component 4 further includes an ultrasonic vibrator 42 disposed inside the concentration monitoring cavity 32 for intermittently vibrating and cleaning the coal ash on the outer surface of the nano coal-removing coating. The ultrasonic vibrator 42 vibrates once every minute for 2 - 5 seconds each time. By the operation of the ultrasonic vibrator 42, the coal ash adhered to the outer surface of the nano coal-removing coating can be shaken off, further improving the monitoring accuracy of the infrared absorption sensor 41.

[0039] Furthermore, as a specific implementation manner, referring to Figure 2 and Figure 3 , the deep concentration monitoring component 4 further includes a blowing cleaning assembly 43. The blowing cleaning assembly 43 includes a blowing head disposed outside the front end of the housing 3 for blowing air onto the outer surface of the nano coal-removing coating and a first air pump disposed inside the concentration monitoring cavity 32 for delivering intermittent high-pressure gas to the blowing head. The first air pump is an intermittent high-pressure air pump. The first air pump works once every hour, 3 - 5 times each time. By intermittently ejecting high-pressure gas, the outer surface of the nano coal-removing coating is cleaned, further improving the monitoring accuracy of the infrared absorption sensor 41.

[0040] Furthermore, as a specific implementation manner, referring to Figure 2 and Figure 3 , the deep concentration monitoring component 4 further includes a constant temperature heating assembly 44. The constant temperature heating assembly 44 includes a heating element 441 disposed inside the concentration monitoring cavity 32, a first temperature sensor 442 for detecting the temperature inside the concentration monitoring cavity 32, and a second temperature sensor 443 for detecting the temperature outside the concentration monitoring cavity 32. By the operation of the heating element 441, the working temperature of the infrared absorption sensor 41 is maintained 4 - 6 °C higher than the external environment of the housing 3, further improving the monitoring accuracy of the infrared absorption sensor 41.

[0041] Referring to Figure 2 , Figure 4 , Figure 5 and Figure 6, the sealing and tightening member 5 includes a sealing assembly 6 for sealing the gap between the outer wall of the housing 3 and the inner wall of the sleeve 2, and a tightening assembly 7 for connecting the housing 3 to the inner wall of the sleeve 2. The sealing assembly 6 includes an inflatable annular airbag 62 coaxially arranged on the outer wall of the housing 3. The tightening assembly 7 includes a hydraulic cylinder body 71 perpendicular to the axis of the housing 3 and a hydraulic system arranged inside the housing 3. A first piston block 72 and a second piston block 73 are fitted in the hydraulic cylinder body 71. A hydraulic chamber 74 is formed between the first piston block 72 and the second piston block 73. A tightening rod 75 is arranged on one end face of the first piston block 72 away from the hydraulic chamber 74. The other end of the tightening rod 75 penetrates the side surface of the housing 3 and is used to closely contact the inner wall of the sleeve 2. A pressure sensor 76 is arranged between the other end of the second piston block 73 away from the hydraulic chamber 74 and the bottom of the hydraulic cylinder body 71. The hydraulic system is in internal communication with the hydraulic chamber 74; several hydraulic cylinder bodies 71 are arranged in each tightening assembly 7, and the several hydraulic cylinder bodies 71 are arranged at equal angles around the axis of the housing 3, preferably four, and the included angle between adjacent hydraulic cylinder bodies 71 is ninety degrees; the hydraulic system includes a hydraulic pump 79 and a hydraulic oil tank 710 arranged inside the sealing and tightening chamber 33. The output end of the hydraulic pump 79 is connected to a hydraulic main pipe 78. Several hydraulic branch pipes 77 in one-to-one communication with each hydraulic chamber 74 are arranged on the hydraulic main pipe 78. A hydraulic valve 711 is arranged on each hydraulic branch pipe 77. An end portion of each tightening rod 75 is provided with a friction block 712. One end face of the friction block 712 away from the tightening rod 75 is an arc surface coaxially arranged with the inner wall of the sleeve 2. After the housing 3 reaches a predetermined position inside the sleeve 2, by the operation of the hydraulic pump 79, each tightening rod 75 can be extended out of the housing 3 and the friction block 712 can be closely attached to the inner wall of the sleeve 2. Each pressure sensor 76 is used to detect the tightening force of the corresponding tightening rod 75, ensuring that the tightening forces of each tightening rod 75 tend to be the same and reach a preset threshold value, thereby realizing the connection between the housing 3 and the sleeve 2. Then each hydraulic valve 711 is in a closed state. During long-term monitoring, due to mining vibrations, the friction blocks 712 will inevitably wear. When the corresponding pressure sensor 76 detects that the tightening force is less than the preset threshold value, the corresponding hydraulic valve 711 is controlled to open, and the tightening force of the tightening rod 75 is compensated by the operation of the hydraulic pump 79, so that each tightening rod 75 always maintains a certain tightening force, ensuring the stability of the connection between the housing 3 and the sleeve 2, and further improving the monitoring accuracy of the infrared absorption type sensor 41.

[0042] Further, as a specific implementation manner, refer to Figure 4 and Figure 5, an annular receiving groove 61 is coaxially arranged on the outer side surface of the outer shell 3 at the position of the sealing and pressing cavity 33. An annular seat for connecting with the bottom of the annular receiving groove 61 is arranged on the inner ring of the annular airbag 62. The sealing assembly 6 further includes a second air pump 63 arranged inside the sealing and pressing cavity 33. The air outlet end of the second air pump 63 is communicated with the inside of the annular airbag 62 through a second air pipe 64. A first air valve and a pressure sensor are arranged on the second air pipe 64. The annular receiving groove 61 can receive the annular airbag 62 when the outer shell 3 is put in or taken out, avoiding the influence on the insertion of the outer shell 3 caused by the annular airbag 62. After each pressing rod 75 is pressed tightly, the annular airbag 62 can be inflated by the operation of the second air pump 63, so that the outer side surface of the annular airbag 62 is closely attached to the inner wall of the sleeve 2. When the air pressure detected by the pressure sensor reaches the preset threshold value, the first air valve is closed and the second air pump 63 stops working.

[0043] Further, as a specific implementation manner, refer to Figure 2 , two groups of pressing components 7 are provided, and the two groups of pressing components 7 are respectively arranged at the front and rear ends of the sealing and pressing cavity 33.

[0044] Further, as a specific implementation manner, refer to Figure 4 , a power supply module 8 is further arranged inside the sealing and pressing cavity 33. The power supply module 8 includes a storage battery; a controller module 11 is further arranged inside the sealing and pressing cavity 33. The storage battery is a lithium battery pack.

[0045] Further, as an implementation manner, refer to Figure 4 , a towing ring is further arranged at the rear end of the outer shell 3, and a towing rope is arranged on the towing ring for taking out the outer shell 3 from the inside of the sleeve 2.

[0046] Further, as an implementation manner, a cable for charging the power supply module 8 and an optical fiber network cable for data transmission with the controller module 11 are further arranged at the rear end of the outer shell 3. The other ends of the towing rope, the cable and the optical fiber network cable all extend outside the monitoring hole 1. The cable is connected with an external power supply, and the optical fiber network cable is connected with an external gas concentration monitoring and warning terminal. Through the gas concentration monitoring and warning terminal, the gas concentration in the deep part of the monitoring hole 1 can be obtained in real time, and a warning is issued when it exceeds the preset threshold value.

[0047] Embodiment 2 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 warning terminal mainly relies on fiber optic network cables. However, when the fiber optic network cables are laid inside the monitoring hole 1, it becomes difficult to lay cables after exceeding a certain length. For the monitoring of gas concentration in some deeper monitoring holes 1, this embodiment uses a wireless method to achieve communication between the controller module 11 and the external gas concentration monitoring and warning terminal. When using the wireless method, it is necessary to solve the charging problem of the power supply module 8 inside the housing 3. In addition, during coal mining, certain vibrations will be generated when underground equipment works (such as drill rigs, shearers) and during blasting.

[0048] The present invention provides a device for real-time monitoring and warning of gas extraction concentration in coal mines. On the basis of Embodiment 1, with reference to Figure 1 and Figure 7 , a LoRa transparent transmission module 10 and a vibration energy conversion component 9 are further provided inside the sealed tightening cavity 33. The vibration energy conversion component 9 includes a vibration energy collection component 91, a double-stage lever amplification mechanism 92, and a piezoelectric conversion component 93. The vibration energy collection component 91 includes a mass block 911 that generates inertial swinging along a predetermined trajectory when affected by mining stress fluctuations. The double-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 sheet 933 that converts the amplified displacement of the mass block 911 into electrical energy. When the monitoring hole 1 is affected by mining stress fluctuations (0.5 - 10 Hz low-frequency vibration), the vibration will be transmitted to the casing 2. The setting of the tightening rod 75 makes the housing 3 rigidly connected to the casing 2, and the vibration will be transmitted to the housing 3. The vibration of the housing 3 can cause the suspended mass block 911 to swing. By providing the LoRa transparent transmission module 10 and the vibration energy conversion component 9, the data transmission between the deep concentration monitoring component 4 and the external gas concentration monitoring and warning terminal is realized. The vibration energy conversion component 9 can convert the vibration during coal mining into electrical energy for the continuous operation of the equipment, solving the problem of difficult cable laying due to the relatively deep depth of the monitoring hole 1.

[0049] Furthermore, as a specific implementation method, with reference to Figure 7 , Figure 8 and Figure 9, the vibration energy harvesting component 91 further includes a limiting guide groove 912. The limiting guide groove 912 includes two arc-shaped side plates 9121 arranged coaxially. An arc-shaped top plate 9122 is provided at the upper ends of the two arc-shaped side plates 9121, and an arc-shaped bottom plate 9123 is provided at the lower ends of the two arc-shaped side plates 9121. An arc-shaped guide groove for the mass block 911 to move along a predetermined trajectory is formed between the two arc-shaped side plates 9121 and the arc-shaped top plate 9122 and the arc-shaped bottom plate 9123. The arc-shaped top plate 9122 and the arc-shaped bottom plate 9123 are both arranged at an inclined angle, and the inclined angle is 15 - 25 degrees. The two arc-shaped side plates 9121 are respectively located on the front and rear sides of the mass block 911, so that the seismic force in the front-back direction of the monitoring hole 1 can be converted into the force in the predetermined trajectory direction of the mass block 911, and the seismic force in the left-right direction of the monitoring hole 1 can also be converted into the 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 arranged at an inclined angle, so that the seismic force in the up-down direction of the monitoring hole 1 can also be converted into the force in the predetermined trajectory direction of the mass block 911. No matter which direction the seismic force is, it can ultimately be converted into the force in the predetermined trajectory direction of the mass block 911, and the random swaying of the mass block 911 is also avoided. A first arc-shaped opening 9124 is coaxially provided on the arc-shaped top plate 9122. A spring 913 is provided at the upper end of the mass block 911, and the upper end of the spring 913 is suspended at the upper end inside the housing 3 through the first arc-shaped opening 9124. A second arc-shaped opening 9125 is coaxially provided on the arc-shaped bottom plate 9123. A swing rod 914 is provided at the lower end of the mass block 911, and a first universal joint 915 is hinged at the lower end of the swing rod 914 after passing through the second arc-shaped opening 9125. The mass block 911 is a tungsten alloy eccentric mass block 911, which is spherical, with a density of 18.5 g / cm 3 , with dimensions of Φ30×15 mm, suspended by a titanium alloy spring 913 with a stiffness coefficient of 5 N / m and subjected to corrosion-resistant treatment. When the borehole is subjected to mining-induced stress fluctuations (0.5 - 10 Hz), the mass block 911 generates inertial swinging, and the multi-directional vibration is converted into a unidirectional impact through the limiting guide groove 912, and the energy utilization rate is increased by 40%. The limiting guide groove 912 converts the vibrations in all directions (up-down, left-right, front-back) in the borehole into a single-direction impact force, enabling the piezoelectric sheet 933 to generate electricity efficiently. The limiting guide groove 912 is made of stainless steel or titanium alloy, which is rust-proof and impact-resistant. When the inclined angle of the arc-shaped top plate 9122 and the arc-shaped bottom plate 9123 is 15°, the conversion efficiency is relatively high. The track width is 0.5 - 1 mm larger than the diameter of the mass block 911 to prevent jamming, and the inner wall is coated with graphite.

[0050] Further, as a specific implementation manner, refer to Figure 7 、 Figure 8 and Figure 10, the short arm end of the first-level lever 921 is hinged to the first universal joint 915, the long arm end of the first-level lever 921 is hinged with a push rod 923 through a second universal joint 924, and the other end of the push rod 923 is hinged to the short arm end of the second-level lever 922 through another second universal joint 924. The first-level lever 921 has a magnification ratio of 3:1, is made of stainless steel, and the hinge points use self-lubricating bearings. The short arm end is connected to a mass 911, and the long arm end transmits motion through a titanium alloy push rod 923. The second-level lever 922 has a magnification ratio of 2:1, is made of carbon fiber composite material, and a polytetrafluoroethylene buffer pad is provided 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.

[0051] Further, as a specific implementation manner, referring to Figure 7 , Figure 8 and Figure 11 , the piezoelectric conversion component 93 further includes a housing 931. The length direction of the housing 931 is horizontally arranged in the left-right direction. Corrugated chutes 932 are provided in the middle of the upper and lower inner walls of the housing 931 along its length direction. A sliding column 934 is fitted in the corrugated chutes 932. Piezoelectric sheets 933 are respectively provided on the front and back sides of the housing 931 inside the corrugated chutes 932. Extrusion ball heads 935 for pressing the piezoelectric sheets 933 are respectively provided at the front and back ends of the sliding column 934. A reciprocating rod 936 is hinged to one side of the sliding column 934 close to the second-level 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 second-level lever 922 through a hinge joint 937. The piezoelectric sheets 933 are made of flexible piezoelectric thin film (PVDF-TrFE) to improve the vibration energy harvesting efficiency. Self-power supply is realized deep in the monitoring hole 1. An oscillation scheme is adopted and combined with ultra-low power consumption sensing technology. It is recommended to be applied in holes deeper than 200 m or in outburst danger areas. Four groups of piezoelectric sheets 933 are connected in series, with dimensions of 20×10×0.5 mm, and the output voltages are superimposed. When the long arm of the second-level lever 922 swings, it can drive the reciprocating rod 936 to move, and then drive the sliding column 934 to move in the corrugated chute 932, and then drive the extrusion ball head 935 to move and press the piezoelectric sheet 933, thereby generating electric energy and storing it in the storage battery.

[0052] The infrared absorption type sensor 41 adopts an intermittent working mode, wakes up for 10 seconds per minute, and saves electric energy while ensuring monitoring.

[0053] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, 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, it should be considered as the scope recorded in this specification.

[0054] The embodiments described above only represent the implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent for the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention shall be subject to the appended claims.

Claims

1. A real-time monitoring and early warning device for the concentration of gas extraction in coal mines, characterized in that, It includes a housing (3) provided in the deep part of the casing (2). At one end of the housing (3) near the deep part of the monitoring hole (1), a deep concentration monitoring component (4) is provided. The deep concentration monitoring component (4) includes an infrared absorption sensor (41). In the middle of the housing (3), a sealing and tightening component (5) for connecting with the inner wall of the casing (2) is also provided. The sealing and tightening component (5) includes a sealing component (6) for sealing the gap between the outer wall of the housing (3) and the inner wall of the casing (2) and a tightening component (7) for connecting the housing (3) with the inner wall of the casing (2). The sealing component (6) includes an inflatable annular airbag (62) coaxially provided on the outer wall of the housing (3). The tightening component (7) includes a hydraulic cylinder body (71) arranged perpendicular to the axis of the housing (3) and a hydraulic system arranged inside the housing (3). A first piston block (72) and a second piston block (73) are fitted in the hydraulic cylinder body (71). A hydraulic cavity (74) is formed between the first piston block (72) and the second piston block (73). On the end face of the first piston block (72) away from the hydraulic cavity (74), a tightening rod (75) is provided. The other end of the tightening rod (75) passes through the side of the housing (3) and is used to closely adhere to the inner wall of the casing (2). A pressure sensor (76) is provided between the end of the second piston block (73) away from the hydraulic cavity (74) and the bottom of the hydraulic cylinder body (71). The hydraulic system is in internal communication with the hydraulic cavity (74).

2. The real-time concentration monitoring and early warning device for gas extraction in coal mines according to claim 1, characterized in that, The housing (3) is in a capsule shape. A partition (31) is coaxially arranged inside the housing (3). A concentration monitoring cavity (32) is formed between the front end face of the partition (31) and the inner wall of the housing (3). A sealing and tightening cavity (33) is formed between the rear end face of the partition (31) and the inner wall of the housing (3). The deep concentration monitoring component (4) is arranged inside the concentration monitoring cavity (32). The sealing and tightening component (5) is arranged at the sealing and tightening cavity (33). A monitoring window (34) communicating with the inside of the concentration monitoring cavity (32) is coaxially provided on the front end face of the housing (3). The detection end of the infrared absorption sensor (41) is located at the position of the monitoring window (34). A self-cleaning mirror surface (35) for sealing and reducing coal ash pollution is also provided inside the inner circle of the monitoring window (34). A nano coal-repellent coating is provided on the outer side surface of the self-cleaning mirror surface (35).

3. The real-time concentration monitoring and early warning device for gas extraction in coal mines according to claim 2, characterized in that, The deep concentration monitoring component (4) further includes an ultrasonic vibrator (42) arranged inside the concentration monitoring cavity (32) for intermittently vibrating and cleaning the coal ash on the outer surface of the nano coal-repellent coating.

4. The real-time concentration monitoring and early warning device for gas drainage in coal mines according to claim 3, wherein The deep concentration monitoring component (4) further includes a blowing cleaning component (43). The blowing cleaning component (43) includes a blowing head arranged outside the front end of the housing (3) for blowing air onto the outer surface of the nano coal-repellent coating and a first air pump arranged inside the concentration monitoring cavity (32) for conveying intermittent high-pressure gas to the blowing head. The first air pump is an intermittent high-pressure air pump.

5. The real-time concentration monitoring and early warning device for gas extraction in coal mines according to claim 1, characterized in that, The deep concentration monitoring component (4) further includes a constant temperature heating assembly (44). The constant temperature heating assembly (44) includes a heating element (441) disposed inside the concentration monitoring chamber (32), a first temperature sensor (442) for detecting the temperature inside the concentration monitoring chamber (32), and a second temperature sensor (443) for detecting the temperature outside the concentration monitoring chamber (32).

6. The real-time monitoring and warning device for the concentration of gas extraction in coal mines according to claim 2, wherein, An annular receiving groove (61) is coaxially provided on the outer side surface of the housing (3) at the position of the sealing and pressing chamber (33). An annular seat for connecting with the bottom of the annular receiving groove (61) is provided on the inner ring of the annular airbag (62). The sealing assembly (6) further includes a second air pump (63) disposed inside the sealing and pressing chamber (33). The air outlet end of the second air pump (63) is communicated with the inside of the annular airbag (62) through a second air pipe (64). A first air valve and a pressure sensor are provided on the second air pipe (64).

7. The real-time monitoring and early warning device for the concentration of gas extraction in coal mines according to claim 2, wherein, A plurality of hydraulic cylinder bodies (71) are provided in each set of the pressing components (7), and the plurality of hydraulic cylinder bodies (71) are sequentially arranged at equal angles around the axis of the housing (3).

8. The real-time concentration monitoring and early warning device for gas extraction in coal mines according to claim 7, characterized in that, The hydraulic system includes a hydraulic pump (79) and a hydraulic oil tank (710) disposed inside the sealing and pressing chamber (33). The output end of the hydraulic pump (79) is communicated with a hydraulic main pipe (78). A plurality of hydraulic branch pipes (77) respectively communicating with each hydraulic chamber (74) are provided on the hydraulic main pipe (78). A hydraulic valve (711) is respectively provided on each hydraulic branch pipe (77).

9. The real-time concentration monitoring and warning device for gas extraction in coal mines according to claim 8, characterized in that, Two sets of the pressing components (7) are provided, and the two sets of the pressing components (7) are respectively disposed at the front and rear ends of the sealing and pressing chamber (33).

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