Protective structure and method for gas extraction drill hole

Abstract

The invention relates to the technical field of coal mine safety protection, and discloses a gas extraction drilling protection structure and method, the gas extraction drilling protection structure comprises a box body, a four-way pipe and an air bag, two through holes are formed in the upper portion of the box body, one through hole is communicated with a second pipeline, the other end of the second pipeline is used for being communicated with a negative pressure pipeline so that gas can be sucked into the negative pressure pipeline, and the other end of the second pipeline is communicated with the air bag; the four-way pipe is connected to the upper portion of the box body, a lower port of the four-way pipe is communicated with the other through hole of the box body through a first pipeline, one transverse port of the four-way pipe is connected with the hole sealing pipe at the position of a drill hole outlet in a sealed mode, and the other transverse port of the four-way pipe is connected with a sealing sleeve used for sealing a gap between the drilling tool and the four-way pipe. Wherein the opening in one side is communicated with a longitudinal port in the top of the four-way pipe through a third pipeline, the opening in the other side of the air bag is communicated with a fourth pipeline used for being communicated with a negative pressure pipeline, and the gas, the coal cinder and the coal cinder water enter the box body and the air bag through the four-way pipe respectively along with spraying of the gas, the coal cinder and the coal cinder water.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mine safety protection, and in particular to a protection structure for a gas extraction borehole and a method thereof. Background Art

[0002] Since coal seams contain gas, with production activities such as coal mining and tunneling, the coal body is broken and gas is accelerated to gush out. In severe cases, it may cause serious accidents such as gas explosion and suffocation of personnel. The most effective gas control measure at present is to construct gas extraction drilling holes underground before the start of production activities to extract the gas stored in the coal body in the target area. By extracting the gas pressure in the coal body, the gas content is greatly reduced. After the gas is extracted, the coal body will not have a large amount of gas precipitation, which affects the safety. The current method is to first expand the hole on the coal wall with an expansion drill bit (the depth of the expansion section is generally 6m to 15m), and then insert a sealing pipe into the expansion section, fill the sealing material between the sealing pipe and the hole wall, and then use a drill bit smaller than the sealing pipe to pass through the sealing pipe to continue to construct the gas extraction drilling hole.

[0003] In the existing extraction and tunneling devices, for the extraction of gas, extraction equipment is usually installed at the sealing pipe. The equipment usually includes a negative pressure pipeline and a rotor induced draft fan connected to the negative pressure pipeline. The high-speed rotation of the rotor induced draft fan generates negative pressure in the negative pressure pipeline, so that the gas leaked from the inner wall of the coal body expansion hole is quickly sucked out. When the drill bit continues to advance, the drill bit inserted into the borehole is equipped with a water outlet to cool the drill bit. The cooling water will leak from the drill bit to the receiving pool at the bottom of the hole. Since the gas pressure at different depths in the coal body is different, the speed at which the coal slag and coal slag water flow into the receiving pool is also different. In order to prevent the outflowing coal slag and coal slag water from splashing on the drilling equipment, the current extraction and tunneling devices are usually equipped with a baffle plate at the receiving point and close to the sealing pipe to block the splashing and impact of coal slag and coal slag water.

[0004] However, when the existing extraction and excavation equipment is at a depth of nearly 100 meters, due to the small inner space of the borehole, there are often problems such as slag discharge and poor drainage, which can easily cause the accumulation of coal slag water and allow the gas pressure to accumulate continuously. When the gas pressure exceeds the limit value, it is easy to drive a large amount of coal slag and coal slag water to spray out of the borehole, so that the baffle plate can hardly completely resist the coal slag and coal slag water that are instantly sprayed out of the hole. The coal slag and the water carrying the coal slag will rebound and splash, causing injuries to personnel, the drilling rig to be covered by coal mud, and even the damage to the working environment. Moreover, the rapidly ejected leaked gas will be mixed with water and slag, and the negative pressure pipe will find it difficult to quickly and independently extract the gas from the mixed gas, water and slag, thereby causing gas leakage in the mine, seriously threatening the lives of personnel. Summary of the invention

[0005] The present invention provides a protective structure for a gas extraction borehole and a method thereof, which can prevent coal slag and water carrying the coal slag from rebounding and splashing to cause injuries to personnel and prevent a large amount of gas leakage.

[0006] The present invention provides a protective structure for gas extraction drilling, comprising: a box body, a four-way pipe, and an air bag. Two through holes are arranged on the upper part of the box body, one of which is connected with a second pipeline, and the other end of the second pipeline is used to be connected with a negative pressure pipeline, so that the gas is sucked into the negative pressure pipeline. The four-way pipe is connected to the upper part of the box body, and the lower end of the four-way pipe is connected with the other through hole of the box body through the first pipeline. One of the transverse ports of the four-way pipe is sealed with a sealing pipe at the outlet of the drilling hole, and the other transverse port is connected with a sealing sleeve for sealing the gap between the drilling tool and the drilling tool. The air bag is connected to the upper part of the four-way pipe. The airbag is provided with two openings, one of which is connected to the top longitudinal port of the four-way pipe through the third pipe, and the other opening of the airbag is connected to the fourth pipe for connecting to the negative pressure pipe. As the gas, coal slag and coal slag water are sprayed out, the three of them enter the box and the airbag respectively through the four-way pipe. The amount of gas in the airbag is greater than the amount of gas in the box, and the amount of coal slag and coal slag water in the box is greater than the amount of coal slag and coal slag water in the airbag, which can prevent the coal slag and the water carrying the coal slag from rebounding and splashing to cause injuries to people and avoid large-scale leakage of gas.

[0007] Preferably, the openings on both sides of the airbag are opposite to each other, and a horizontal screen tube is connected between the two opposite openings of the airbag. The two ends of the screen tube are respectively connected to the two openings of the airbag, and the two ends of the screen tube are respectively inserted and fixedly connected in the third pipeline and the fourth pipeline. The screen tube has multiple screen holes along its circumference. The screen tube can achieve the effect of auxiliary support for the openings on both sides of the airbag, and the screen tube can prevent high-speed splashing coal slag and coal slag water from entering the airbag and causing damage to the inner wall of the airbag.

[0008] Preferably, a barrier net for blocking coal slag from entering the fourth pipeline is provided at a position of the screen pipe close to the fourth pipeline.

[0009] Preferably, a through hole is provided in the lower side wall of the box body, and an opening is provided below the airbag. The opening at the bottom of the airbag and the through hole at the bottom of the box body are both connected to control valves. The other ends of the two control valves are connected to the fifth pipeline, and the two fifth pipelines are used to be connected to the slag discharge pipeline. The other ends of the two control valves are connected to the fifth pipeline, and the two fifth pipelines are used to be connected to the slag discharge pipeline.

[0010] Preferably, pneumatic valves are connected between the box and the second pipeline, and between the airbag and the fourth pipeline, so as to realize remote control of opening and closing of the second pipeline and the fourth pipeline.

[0011] Preferably, considering that drilling spraying occurs suddenly, there has been a lack of monitoring means in the past, and only the drilling depth when the spraying occurs can be recorded, making it difficult to analyze the pattern of the spraying. Therefore, a control terminal is connected to the box, and the control terminal includes a data processing unit and a control unit. Two pneumatic valves and two control valves are electrically connected to the control unit. The data processing unit of the control terminal is used for input analysis of parameters such as drill bit, gas pressure, gas concentration, and drill rod displacement, so as to automatically control the remote automatic opening and closing of each pneumatic valve and each control valve through the control unit.

[0012] Preferably, the control terminal also includes a transceiver unit for receiving and sending data. Three through holes are opened on the top of the four-way pipe. A gas concentration sensor for detecting gas concentration, a pressure sensor for detecting gas pressure, and a visual recognition camera for monitoring the horizontal displacement state of the drill rod of the drilling tool are respectively inserted and sealed in the three through holes. The gas concentration sensor, pressure sensor and visual recognition camera are all electrically connected to the transceiver unit of the control terminal.

[0013] Preferably, the airbag is made of rubber or waterproof canvas material and can be deformed when inflated.

[0014] Preferably, the third pipeline and the fourth pipeline are both provided with fixing sleeves, the upper parts of the fixing sleeves are fixedly connected to the top coal body via lifting chains, the top of the airbag is fixedly connected with a plurality of hanging ears, and the hanging ears are fixedly connected to the top coal body via lifting chains.

[0015] The present invention also includes a method for protecting a protective structure of a gas extraction borehole, comprising the following steps: S1, control the drill bit of the drilling tool to penetrate into the four-way pipe from one side of the sealing sleeve horizontally, until the drill bit passes through the four-way pipe and enters the sealing pipe, and control the rotation and feeding of the drill rod; S2. As gas, coal slag and coal slag water are ejected outward at high speed, the gas concentration sensor and the pressure sensor sense in advance and send the data to the transceiver unit of the control terminal. The data processing unit converts the signal received by the transceiver unit into a control signal to the control unit. The control unit remotely fully opens the pneumatic valve and controls the control valve to be in a closed state. S3. As gas, coal ash and coal ash water enter the four-way pipe, a large amount of gas flows into the air bag first to make the air bag expand rapidly. Under the action of negative pressure suction force, they are sucked into the second pipeline and the fourth pipeline respectively until they are sucked away by the negative pressure pipeline. The coal ash and coal ash water enter the box body first by gravity and settle.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention can achieve closed treatment of gas, coal slag and coal slag water when gas, coal slag and coal slag water have spray holes by means of the arranged four-way pipe, box, air bag, first pipeline and third pipeline, thereby avoiding as much as possible the leakage of gas in the mine, the rebound and splashing of water carrying coal slag and coal slag causing injuries to personnel, the covering of drilling rigs by coal mud and even the destruction of the working environment, and at the same time, it also solves the problem that gas is difficult to be quickly and comprehensively sucked out by the negative pressure pipeline when it is under high pressure and has a high content. The problem of large-scale leakage of gas is eventually caused by the present invention. The present invention also utilizes the characteristics of light gas and heavy coal ash and coal ash water to achieve the effect of classified treatment of gas, coal ash and coal ash water. Specifically, by using an air bag as the core to fill the gas, the deformation and expansion of the air bag is utilized to cope with the high-pressure and large amount of gas, thereby having a buffering effect for gas suction, and enabling the negative pressure pipeline to quickly and separately suck most of the gas from the mixed gas, water and slag behind the nozzle, thereby avoiding gas leakage in the mine and ensuring the life safety of personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic structural diagram of a gas extraction borehole protection structure provided by an embodiment of the present invention; Figure 2 for Figure 1 A partial enlarged view of part A; Figure 3 A schematic structural diagram of a gas extraction borehole protection structure provided by an embodiment of the present invention; Figure 4 A schematic diagram of the structure of a screen pipe in a protective structure for a gas extraction borehole provided by an embodiment of the present invention; Figure 5 A schematic diagram of the principle of predicting the probability of blowout using a BP network for a gas extraction borehole protection structure provided by an embodiment of the present invention; Figure 6 A flowchart of a method for providing a protective structure for a gas extraction borehole provided in an embodiment of the present invention.

[0018] Description of reference numerals: 1. Four-way pipe; 2. Sealing sleeve; 3. Box; 4. First pipeline; 5. Second pipeline; 6. Air bag; 7. Third pipeline; 8. Fourth pipeline; 9. Control valve; 10. Screen tube; 11. Screen hole; 12. Barrier net; 13. Fifth pipeline; 14. Pneumatic valve; 15. Control terminal; 16. Gas concentration sensor; 17. Pressure sensor; 18. Visual recognition camera; 19. Fixing sleeve; 20. Lifting chain; 21. Hanging ear; 22. Lifting chain. DETAILED DESCRIPTION

[0019] A specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation.

[0020] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the technical solutions of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0021] refer to Figure 1 , Figure 2 and Figure 3 The present invention provides a protective structure for gas extraction drilling, comprising: a box body 3, a four-way pipe 1, and an air bag 6. Two through holes are provided on the upper part of the box body 3, one of which is connected with a second pipeline 5. The other end of the second pipeline 5 is used to be connected with a negative pressure pipeline for sucking gas, so that the gas is sucked into the negative pressure pipeline. The four-way pipe 1 is connected to the upper part of the box body 3, and the lower end of the four-way pipe 1 is connected with another through hole of the box body 3 through a first pipeline 4. One of the transverse ports of the four-way pipe 1 is sealed with a sealing pipe at the outlet of the drilling hole, and the other transverse port is connected with a sealing pipe for sealing. A sealing sleeve 2 is provided to block the gap between the gas bag 6 and the drilling tool, and an airbag 6 is connected to the top of the four-way pipe. The airbag 6 has two openings, one of which is connected to the top longitudinal port of the four-way pipe 1 through a third pipeline 7, and the other opening of the airbag 6 is connected to a fourth pipeline 8 for connecting to a negative pressure pipeline. As the gas, coal slag and coal slag water are sprayed out, the three of them enter the box 3 and the airbag 6 respectively through the four-way pipe 1. The amount of gas in the airbag 6 is greater than the amount of gas in the box 3, and the amount of coal slag and coal slag water in the box 3 is greater than the amount of coal slag and coal slag water in the airbag 6.

[0022] In the above embodiments, the present invention can achieve closed treatment of gas, coal slag and coal slag water when gas, coal slag and coal slag water have spray holes by means of the arranged four-way pipe 1, box body 3, air bag 6, first pipeline 4 and third pipeline 7, thereby avoiding the leakage of gas in the mine as much as possible, and the occurrence of situations such as injuries to personnel, covering of drilling rigs with coal mud and even destruction of the working environment caused by the rebound and splashing of water and coal slag carrying coal slag, and solving the problem that gas is difficult to be sucked by negative pressure pipelines when it is under high pressure and has a high content, thereby causing leakage. At the same time, the present invention can take advantage of Taking advantage of the fact that gas is relatively light in weight while coal slag and coal slag water are relatively heavy, the effect of classified treatment of gas, coal slag and coal slag water is achieved. Specifically, the air bag 6 is used as the core to fill the gas, and the deformation and expansion of the air bag 6 is utilized to cope with high-pressure and large-volume gas, thereby providing a buffer for gas suction, and enabling the negative pressure pipeline to quickly and separately suck most of the gas from the gas, water and slag mixed behind the nozzle, thereby avoiding gas leakage in the mine and ensuring the life safety of personnel. The sealing sleeve 2 is made of a high molecular polyethylene material and is provided with a sealing ring inside.

[0023] Further, refer to Figure 4 The openings on both sides of the airbag 6 are opposite to each other, and a horizontal screen tube 10 is connected between the two opposite openings of the airbag 6. The two ends of the screen tube 10 are respectively connected to the two openings of the airbag 6. The two ends of the screen tube 10 are respectively inserted and fixedly connected to the third pipeline 7 and the fourth pipeline 8. The screen tube 10 has a plurality of screen holes 11 along its circumference.

[0024] In the above embodiments, the screen tube 10 is provided to provide auxiliary support for the openings on both sides of the airbag 6, and the screen tube 10 can prevent high-speed splashing coal slag and coal slag water from entering the airbag 6 and damaging the inner wall of the airbag 6. The screen hole 11 allows the coal slag and coal slag water to fall to the bottom of the airbag 6.

[0025] Further, refer to Figure 4 A through hole is also provided on the lower side wall of the box body 3, and an opening is also provided below the airbag 6. The opening at the bottom of the airbag 6 and the through hole at the bottom of the box body 3 are both connected to a control valve 9. The other ends of the two control valves 9 are both connected to a fifth pipeline 13. The two fifth pipelines 13 are used to be connected to the slag discharge pipeline. The other ends of the two control valves 9 are both connected to a fifth pipeline. The two fifth pipelines are used to be connected to the slag discharge pipeline. A barrier net 12 for blocking coal slag is arranged near the fourth pipeline 8 of the screen pipe 10.

[0026] In the above embodiments, the fifth pipeline 13 is provided to achieve a unified discharge effect for the ash water and the ash, and the barrier net 12 is provided to prevent the ash and the ash water from flowing into the fourth pipeline 8 .

[0027] Further, refer to Figure 1 The other ends of the two control valves 9 are connected to the fifth pipeline 13, and the two fifth pipelines 13 are connected to the slag discharge pipeline.

[0028] Further, refer to Figure 1 Pneumatic valves 14 are connected between the box body 3 and the second pipeline 5, and between the airbag 6 and the fourth pipeline 8.

[0029] In the above embodiments, the pneumatic valve 14 is provided to remotely control the opening and closing of the second pipeline 5 and the fourth pipeline 8 , specifically, the solenoid valve is used to control the opening and closing of the gas circuit and the opening of the pneumatic valve 14 .

[0030] Further, refer to Figure 1 and Figure 2 Considering that drilling spraying occurs suddenly, there has been a lack of monitoring means in the past. Only the drilling depth when spraying occurs can be recorded, and it is difficult to analyze the regularity of spraying. Therefore, the present invention is connected to a control terminal 15 on the box 3. The control terminal 15 includes a data processing unit and a control unit. The two pneumatic valves 14 and the two control valves 9 are electrically connected to the control unit. The data processing unit of the control terminal 15 is used for input analysis of parameters such as drill bit, gas pressure, gas concentration, and drill rod displacement, so as to automatically control the remote automatic opening and closing of each pneumatic valve 14 and each control valve 9 through the control unit.

[0031] The control terminal 15 also includes a transceiver unit for receiving and sending data. Three through holes are opened on the top of the four-way pipe 1. A gas concentration sensor 16 for detecting gas concentration, a pressure sensor 17 for detecting gas pressure, and a visual recognition camera 18 for monitoring the horizontal displacement state of the drill pipe of the drilling tool are respectively inserted and sealed in the three through holes. The gas concentration sensor 16, the pressure sensor 17 and the visual recognition camera 18 are all electrically connected to the transceiver unit of the control terminal 15.

[0032] In the above embodiments, the present invention inputs data information such as borehole diameter, drill bit diameter, drill rod diameter, and borehole inclination into the data processing unit of the control terminal 15 before drilling construction, and records the borehole depth, borehole gas pressure, and gas concentration during the drilling construction. Specifically, the reason why pressure and concentration are recorded at the same time is that the borehole four-way pipe 1 belongs to a semi-enclosed space, and its sealing degree is closely related to the gap between the outer sealing sleeve 2 of the four-way horizontal pipe and the drill rod, but the sealing sleeve 2 is essentially made of hard plastic or rubber, and its wear degree and replacement timeliness are often unstable due to the judgment of on-site operators. The use of concentration and pressure dual indicators can effectively offset the impact caused by different sealing degrees. If the sealing sleeve 2 is severely worn and the sealing of the four-way pipe 1 is not good, then After a blowout occurs, because it is connected to the outside world, pressure is not easy to accumulate quickly, and judging the blowout by pressure data is relatively lagging. However, precisely because it is connected to the outside world, the gas concentration in the four-way pipe 1 is relatively low. Once a blowout occurs, the concentration will immediately rise sharply, which can effectively judge the blowout. If the sealing sleeve 2 is replaced in time, the gap between it and the drill pipe is small, and the sealing degree of the four-way pipe 1 is high, then under normal circumstances, the four-way pipe 1 has a high gas concentration. After a blowout occurs, the concentration in the four-way pipe 1 does not rise significantly, and the concentration is lagged as a judgment indicator. However, because the sealing degree is high, pressure is easy to accumulate, so pressure can be used as an effective sensitive indicator for judging the blowout. A big data analysis model for drilling construction blowouts can be established through the control terminal 15, and a more accurate judgment can be made on the mechanism and law of blowouts.

[0033] At the same time, the prediction model of the data processing unit is combined with the gas concentration sensor 16, the pressure sensor 17 and the visual recognition camera 18 to record the gas concentration, gas pressure, drilling depth and other data in real time. Once the blowout occurs, if the gas pressure, concentration change amplitude or concentration absolute value reaches the set value in a short period of time, this set value is initially set according to the gas pressure and gas content of the coal seam during drilling, and then a recommended value is given according to the big data analysis model. Then it is immediately determined that the blowout has occurred. By controlling the control unit, the control valve 9 is closed, thereby realizing the opening of the pneumatic valve 14. In this way, the blowout can be quickly responded to, the gas is extracted, and safety is ensured. The control valve 9 can be closed in time after the blowout is completed to avoid the negative pressure suction effect of the extraction system. When the blowout is completed, the control valves 9 are opened to effectively discharge the coal slag and coal slag water. This design effectively avoids the coal slag water and coal slag filling the box 3 or the air bag 6, causing subsequent water and coal slag to enter the second pipeline 5 or the fourth pipeline 8, reducing the risk of blockage and interruption, and improving the extraction efficiency.

[0034] The use of the visual recognition camera 18 not only improves the accuracy of drilling depth calculation, but also provides more data support for the establishment of the spray hole model. At the same time, the application of the fusion algorithm makes the drilling construction process more transparent, facilitates assessment and management, and improves the standardization and efficiency of the operation.

[0035] Specifically, the present invention establishes a blowhole degree evaluation model using a BP neural network according to the borehole diameter, drill bit diameter, drill rod diameter, borehole inclination, borehole depth, orifice gas pressure, and orifice gas concentration. When the blowhole degree evaluation is higher than a set threshold, it is determined that a blowhole has occurred. In this way, the blowhole can be quickly responded to, the gas can be extracted, and safety can be ensured, and the valves can be opened and closed in time after the blowhole ends.

[0036] Specifically, Figure 5 As shown, the input layer data is , which respectively represent the seven physical parameters of borehole diameter, drill bit diameter, drill rod diameter, borehole inclination, borehole depth, orifice gas pressure and orifice gas concentration.

[0037] There are two hidden layers in the intermediate calculation process, named , the data is processed from the input layer through linear transformation of weight values ​​and bias terms, and then passes through the activation layer to obtain the output of the hidden layer, which is the input of the next layer.

[0038] Input layer ( ) to the hidden layer ( ) parameters are in is the weight value, is the bias term; the hidden layer ( ) to the hidden layer ( ) parameters are in is the weight value, is the bias term; the hidden layer ( ) to the output layer ( ) parameters are ,in is the weight value, is the bias term. The activation function is , , . So the model layers are set as:

[0039] During the calculation process, all data input is in the form of vectors.

[0040] In the above formula, is the transpose of the vector, is the hidden layer ( ) output, is the hidden layer ( ) output, is the model output, that is, the probability of the occurrence of the nozzle predicted by the model: Among them, the activation function , Both use the ReLU (rectified linear unit) function: Weight value in the formula are the coefficients of connected neurons (neurons are represented by circular symbols).

[0041] In this model, weights determine how much the input parameters affect the output (i.e., the predicted probability). The weights are constantly adjusted during the training process to make the model's predictions as accurate as possible.

[0042] Bias is an additional parameter to the neuron output, providing a fixed offset when there is no input.

[0043] The bias term can make the activation function of the model better fit the training data, thereby improving the predictive ability of the model.

[0044] Activation function in the model , , is a crucial component that introduces nonlinearity, enabling the model to better learn and represent complex data relationships.

[0045] Further, refer to Figure 1 , the airbag 6 is made of rubber or waterproof canvas.

[0046] In the above embodiments, by limiting the airbag 6 to be made of rubber or waterproof canvas material, it can be deformed when inflated to cope with high-pressure and large-volume gas, thereby achieving a buffering effect for gas extraction.

[0047] Further, refer to Figure 1 The third pipeline 7 and the fourth pipeline 8 are both provided with a fixing sleeve 19, and the upper part of the fixing sleeve 19 is fixedly connected to the top coal body through a lifting chain 20. The top of the airbag 6 is fixedly connected with a plurality of hanging ears 21, and the hanging ears 21 are fixedly connected to the top coal body through a lifting chain 22.

[0048] In the above embodiments, the fixing sleeve 19 is fixedly connected to the third pipeline 7 and the fourth pipeline 8 .

[0049] Further, refer to Figure 6 The present invention also includes a method for protecting a protective structure of a gas extraction borehole, comprising the following steps: S1, control the drill bit of the drilling tool to penetrate into the four-way pipe 1 from one side of the sealing sleeve 2 horizontally, until the drill bit passes through the four-way pipe 1 and enters the sealing pipe, and control the rotation and feeding of the drill rod; S2. As the gas, coal slag and coal slag water are ejected outward at a high speed, the gas concentration sensor 16 and the pressure sensor 17 sense in advance and send data to the transceiver unit of the control terminal 15. The data processing unit converts the signal received by the transceiver unit into a control signal to the control unit. The control unit remotely fully opens the pneumatic valve 14 and controls the control valve 9 to be in a closed state. S3. As the gas, coal ash and coal ash water enter the four-way pipe 1, a large amount of gas preferentially flows into the airbag 6 to make the airbag 6 expand rapidly. Under the action of the negative pressure suction force, they are respectively sucked into the second pipeline 5 and the fourth pipeline 8 until they are sucked away by the negative pressure pipeline. The coal ash and coal ash water preferentially enter the box body 3 by gravity and settle.

[0050] Specifically, when the orifice phenomenon does not occur in the normal state, the pneumatic valve 14 connected to the airbag 6 is closed, and the two control valves 9 are opened. The coal slag and coal slag water enter the box body 3 due to gravity, and the gas is discharged by the pneumatic valve 14 of the box body 3, and the water slag is discharged by the control valve 9. When the orifice phenomenon occurs, a large amount of gas enters the four-way pipe 1 along with the water slag. As the gas, coal slag and coal slag water are sprayed out at high speed, the gas concentration sensor 16 and the pressure sensor 17 sense in advance and send the data to the transceiver unit of the control terminal 15. The data processing unit converts the signal received by the transceiver unit into a control signal to the control unit. The control unit remotely fully opens the pneumatic valve 14 and controls the control valve 9 to be in a closed state. At this time, the gas with a large amount of pressure passes through the third The pipeline 7 enters the airbag 6 and enters the screen tube 10 to release the pressure on the airbag 6. The airbag 6 can play a good buffering role due to its material characteristics. After the water slag sinks to the airbag 6, it is discharged by the control valve 9, and the high-pressure gas is discharged to the fourth pipeline 8 through the pneumatic valve 14. After that, when the nozzle pressure and concentration detected by the gas concentration sensor 16 and the pressure sensor 17 tend to be stable, the pneumatic valve 14 connected to the box 3 is opened, and the pneumatic valve 14 connected to the airbag 6 is closed to avoid the evacuation of the extraction pipeline. Due to the visual recognition camera 18 set in the four-way pipe 1, the device can visually recognize the advancement and withdrawal of the drill rod in real time in a dark environment, accurately record the number of advancement and withdrawal, and can assist in judging the nozzle through deep learning and the image features of the nozzle.

[0051] In summary, the present invention can, on the basis of ensuring blowout prevention holes and avoiding gas leakage, significantly improve the safety and efficiency of coal mine gas extraction drilling operations through technical features such as accurate prediction, rapid response, effective separation and discharge, intelligent monitoring and depth calculation, thus providing a strong guarantee for safe production in coal mines.

[0052] The above disclosures are only several specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A protective structure for a gas extraction borehole, characterized in that: include: The box body (3) has two through holes on its upper portion, one of the through holes being connected to a second pipeline (5), and the other end of the second pipeline (5) being connected to a negative pressure pipeline for extracting gas; A four-way pipe (1) is connected to the top of the box (3); a lower end of the four-way pipe (1) is connected to another through hole of the box (3) via a first pipeline (4); one of the transverse ends of the four-way pipe (1) is sealed with a sealing pipe at a borehole outlet; and the other transverse end is connected with a sealing sleeve (2) for sealing a gap between the drilling tool and the drilling tool; The airbag (6) is connected to the top of the four-way pipe. The airbag (6) has two openings, one of which is connected to the top longitudinal port of the four-way pipe (1) through a third pipe (7). The other opening of the airbag (6) is connected to a fourth pipe (8) for connecting to the negative pressure pipe. As the gas, coal slag and coal slag water are sprayed out, they enter the box (3) and the airbag (6) respectively through the four-way pipe (1). The amount of gas in the airbag (6) is greater than the amount of gas in the box (3), and the amount of coal slag and coal slag water in the box (3) is greater than the amount of coal slag and coal slag water in the airbag (6).

2. A protective structure for a gas extraction borehole according to claim 1, characterized in that: The openings on both sides of the airbag (6) are opposite to each other, a transverse screen tube (10) is connected between the two opposite openings of the airbag (6), two ends of the screen tube (10) are respectively connected to the two openings of the airbag (6), two ends of the screen tube (10) are respectively inserted and fixedly connected in the third pipeline (7) and the fourth pipeline (8), and the screen tube (10) is provided with a plurality of screen holes (11) along its circumference.

3. A protective structure for a gas extraction borehole as claimed in claim 2, characterized in that: A barrier net (12) for blocking coal slag is provided at a position of the screen pipe (10) close to the fourth pipeline (8).

4. A protective structure for a gas extraction borehole according to claim 1, characterized in that: A through hole is also provided on the lower side wall of the box body (3), and an opening is also provided on the lower side of the airbag (6). The opening at the bottom of the airbag (6) and the through hole at the bottom of the box body (3) are both connected to a control valve (9). The other ends of the two control valves (9) are both connected to a fifth pipeline (13). The two fifth pipelines (13) are used to be connected to a slag discharge pipeline.

5. A protective structure for a gas extraction borehole as claimed in claim 4, characterized in that: A pneumatic valve (14) is connected between the box body (3) and the second pipeline (5), and between the air bag (6) and the fourth pipeline (8).

6. A protective structure for a gas extraction borehole as claimed in claim 5, characterized in that: The box (3) is connected to a control terminal (15), the control terminal (15) comprising a data processing unit and a control unit, the two pneumatic valves (14) and the two control valves (9) are electrically connected to the control unit, the data processing unit of the control terminal (15) is used for input analysis of parameters such as drill bit, gas pressure, gas concentration, drill rod displacement, etc., and the remote automatic opening and closing of each pneumatic valve (14) and each control valve (9) is controlled by the control unit.

7. A protective structure for a gas extraction borehole as claimed in claim 6, characterized in that: The control terminal (15) further comprises a transceiver unit for receiving and sending data. The top of the four-way pipe (1) is provided with three through holes. A gas concentration sensor (16) for detecting gas concentration, a pressure sensor (17) for detecting gas pressure, and a visual recognition camera (18) for monitoring the horizontal displacement state of a drill rod of a drilling tool are respectively inserted and sealed in the three through holes. The gas concentration sensor (16), the pressure sensor (17), and the visual recognition camera (18) are all electrically connected to the transceiver unit of the control terminal (15).

8. A protective structure for a gas extraction borehole as claimed in claim 1, characterized in that: The airbag (6) is made of rubber or waterproof canvas.

9. A protective structure for a gas extraction borehole as claimed in claim 1, characterized in that: The third pipeline (7) and the fourth pipeline (8) are both sleeved with a fixing sleeve (19), and the top of the fixing sleeve (19) is fixedly connected to the top coal body via a lifting chain (20). The top of the airbag (6) is fixedly connected to a plurality of hanging ears (21), and the hanging ears (21) are fixedly connected to the top coal body via a lifting chain (22).

10. A method for protecting a protective structure of a gas extraction borehole according to claim 7, characterized in that: The following steps are involved: S1. As the gas, coal slag and coal slag water are ejected outward at a high speed, the gas concentration sensor (16) and the pressure sensor (17) sense in advance and send data to the transceiver unit of the control terminal (15). The data processing unit converts the signal received by the transceiver unit into a control signal to the control unit. The control unit remotely fully opens the pneumatic valve (14) and controls the control valve (9) to be in a closed state. S2. As the gas, coal slag and coal slag water enter the four-way pipe (1), a large amount of the gas preferentially flows into the air bag (6) to rapidly expand the air bag (6). Under the action of the negative pressure suction force, the gas is respectively sucked into the second pipeline (5) and the fourth pipeline (8) until it is sucked away by the negative pressure pipeline. The coal slag and coal slag water preferentially enter the box body (3) by gravity and settle.

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