Gas extraction drilling multi-parameter monitoring device and system

Abstract

The invention discloses a gas extraction drilling multi-parameter monitoring device and system, and belongs to the technical field of gas extraction drilling monitoring, the gas extraction drilling multi-parameter monitoring device comprises a main shell, the two ends of the main shell are provided with a gas inlet connector and a gas outlet connector respectively, the gas inlet connector and the gas outlet connector are used for being connected with an extraction pipeline, and a venturi variable flow channel is arranged in the main shell; symmetrically-arranged net plates are installed on the throat portion of the venturi variable flow channel, and ultrasonic sensing probes are installed on the surfaces, close to each other, of the two net plates. The venturi variable flow channel integrates monitoring of four kinds of parameters including flow, concentration, temperature and pressure, the defect of single parameter monitoring of existing equipment is overcome, meanwhile, temperature and pressure data provide real-time compensation for the concentration and the flow, parameter accuracy is ensured, the extraction amount can be accurately calculated, and a reliable basis is provided for extraction effect evaluation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of gas extraction drilling monitoring, and particularly relates to a gas extraction drilling multi-parameter monitoring device and system. BACKGROUND

[0002] The coal seam structure area is affected by changes in conditions such as ground stress, coal seam thickness, coal body adsorption capacity, gas original pressure content and coal seam permeability, and there is a gas anomaly area with gas enrichment and more difficult gas extraction. A large number of extraction drilling holes are constructed before the excavation of a coal and gas outburst mine, the number of drilling holes and drilling footage are huge, but only serving a single engineering purpose lacks a system of thinking that one drilling hole is an engineering and one hole is used for multiple purposes.

[0003] The existing gas extraction drilling hole monitoring equipment is mainly realized by detecting parameters such as gas concentration, temperature and pressure. Common detection equipment includes a gas concentration meter, a temperature sensor and a pressure sensor. However, these devices can only collect a single parameter, and there are problems such as complicated operation and complex structure, and actual detection in the mine is time-consuming and labor-intensive. SUMMARY

[0004] The purpose of the present application is to provide a gas extraction drilling multi-parameter monitoring device and system to solve the problems raised in the background.

[0005] To achieve the above purpose, the present application provides the following technical scheme: a gas extraction drilling multi-parameter monitoring device, comprising a main shell, the two ends of the main shell are respectively provided with an air inlet and an air outlet for connecting the extraction pipeline, a Venturi variable diameter flow channel is arranged in the main shell, the throat of the Venturi variable diameter flow channel is provided with symmetrically arranged mesh plates, and ultrasonic sensing probes are arranged on the surfaces of the two groups of mesh plates close to each other.

[0006] Preferably, a plurality of diffusion holes are arranged on the inner wall of the Venturi variable diameter flow channel, an infrared gas sensor is fixed in the plurality of diffusion holes through an internally hollow mounting seat, and a hydrophobic and breathable dustproof film is arranged at the inlet of the plurality of diffusion holes.

[0007] Preferably, a temperature and pressure integrated sensor is embedded and arranged in the straight section before the throat of the Venturi variable diameter flow channel or the expansion section after the throat, and the pressure sensing surface of the temperature and pressure integrated sensor is flush with the inner wall of the flow channel.

[0008] Preferably, a fine filter element is embedded in the air inlet, and the fine filter element is used for efficiently removing large particle coal dust and water droplets in the gas, and the fine filter element adopts a structure of a metal framework plus a composite filter layer.

[0009] Preferably, the inside of the main shell is provided with a connecting pipe, and the connecting pipe is located above the Venturi variable-diameter flow channel, one end of the connecting pipe extends into the inside of the Venturi variable-diameter flow channel and is connected with a bidirectional nozzle, the inside of the bidirectional nozzle is provided with an electromagnetic valve, the other end of the connecting pipe penetrates through the outer wall of one side of the main shell and is connected with a high-pressure gas pipe, and the high-pressure gas pipe is used to transport a high-pressure gas source.

[0010] Preferably, a gas extraction drilling multi-parameter monitoring system comprises a pretreatment module, a multi-parameter sensing module, a self-cleaning module, a control processing module and a communication module, the pretreatment module filters the gas entering the main shell through a fine filter element, the multi-parameter sensing module detects multiple parameters of the gas flowing through the Venturi variable-diameter flow channel in real time through a sensor, the self-cleaning module is used to perform a periodic or triggered cleaning action, which removes impurities attached to the sensor sensitive element or the wall of the Venturi variable-diameter flow channel through a high-pressure gas source, the control processing module is electrically connected with the multi-parameter sensing module and the self-cleaning module, respectively, and is used to control the data acquisition and operation of the multi-parameter sensing module, process the data by using a built-in adaptive algorithm, and control the start of the electromagnetic valve, and the communication module is electrically connected with the control processing module and is used to send the processed data to an external monitoring system.

[0011] Preferably, the action of the self-cleaning module is triggered by at least one of the following modes: timing trigger based on a preset time period, trigger based on a sensor data threshold value, or remote instruction trigger received from an external system.

[0012] Preferably, the adaptive algorithm built in the control processing module comprises:

[0013] a flow range adaptive sub-algorithm for dynamically adjusting the transmission frequency and reception gain of the ultrasonic sensing probe according to historical flow data;

[0014] a concentration compensation sub-algorithm for real-time compensation of gas concentration readings according to temperature and pressure data;

[0015] a filter parameter adaptive sub-algorithm for dynamically adjusting the window size of a digital filter according to flow rate changes.

[0016] Preferably, the system further comprises:

[0017] a downhole communication ring network interacting with the communication module and used for transmitting monitoring data;

[0018] a ground monitoring center comprising a server and a monitoring software platform, the server receives and displays, stores and analyzes real-time data uploaded from downhole through the monitoring software platform, and intelligently evaluates and warns the drilling extraction effect.

[0019] Preferably, the monitoring software platform can issue control instructions to the designated multi-parameter adaptive monitoring device for remote configuration parameters or triggering self-cleaning operation.

[0020] Compared with the prior art, the present application has the following advantages:

[0021] 1、The Venturi variable-diameter flow channel integrates four types of parameter monitoring: flow, concentration, temperature and pressure, solving the single parameter monitoring defect of existing equipment, at the same time, the temperature and pressure data provide real-time compensation for concentration and flow, ensuring parameter accuracy, accurately calculating the extraction amount, and providing a reliable basis for extraction effect evaluation.

[0022] 2、The present application can reduce the frequency of manual maintenance through high-pressure gas self-cleaning, at the same time, the hydrophobic and breathable dustproof film further blocks water vapor and coal dust, which can prolong the service life of the sensor and reduce the risk of downhole operation and operation and maintenance cost.

[0023] 3、The present application dynamically optimizes data acquisition accuracy through adaptive algorithm, avoids the interference of temperature and pressure changes and flow fluctuations on measurement, and realizes real-time monitoring, intelligent analysis, automatic early warning and remote control integration of the ground monitoring center without manual on-site intervention, when the extraction parameters are abnormal, the early warning and instruction issuing can be completed within 5 minutes, greatly improving the timeliness of control. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a schematic diagram of the three-dimensional structure of the present application;

[0025] Figure 2 is a schematic diagram of the cross-sectional three-dimensional structure of the present application;

[0026] Figure 3 is a schematic diagram of the layout of the ultrasonic sensing probe, temperature and pressure integrated sensor and infrared gas sensor of the present application;

[0027] Figure 4 is a flowchart of the present application.

[0028] In the figure: 1, main housing; 2, gas inlet; 3, gas outlet; 4, Venturi variable-diameter flow channel; 5, screen; 6, ultrasonic sensing probe; 7, hydrophobic and breathable dustproof film; 8, temperature and pressure integrated sensor; 9, fine filter element; 10, connecting pipe; 11, high-pressure gas pipe; 12, two-way nozzle. DETAILED DESCRIPTION

[0029] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0030] Please refer to Figures 1-4 The present application provides a kind of gas extraction borehole multi-element parameter monitoring device, including main casing 1, the two ends of main casing 1 are equipped with the gas inlet interface 2 and the gas outlet interface 3 for connecting extraction pipeline, main casing 1 is equipped with a section Venturi variable diameter flow channel 4, the throat of Venturi variable diameter flow channel 4 is equipped with symmetrically arranged screen 5, two groups of screen 5 mutually close surface is equipped with ultrasonic sensing probe 6.

[0031] Further, ultrasonic sensing probe 6 is installed in the throat of Venturi variable diameter flow channel 4 with the way of opposite emission, for measuring gas flow rate and flow, screen 5 adopts the sintered net of stainless steel with thickness 2-3mm, porosity 30%-40%, which can provide stable mounting surface for ultrasonic sensing probe 6, and can also uniformly rectify the airflow at the throat, reduce the influence of flow field disturbance on ultrasonic measurement, Venturi variable diameter flow channel 4 is a section of variable diameter flow channel with Venturi tube structure, which guarantees stable transition of flow rate and improves the accuracy of flow monitoring.

[0032] The inner wall of Venturi variable diameter flow channel 4 is provided with a plurality of diffusion holes, an infrared gas sensor is fixed in the plurality of diffusion holes through an internally hollow mounting seat.

[0033] Further, the infrared gas sensor adopts non-spectroscopic infrared technology, has strong anti-interference ability, and is used for accurately measuring methane concentration. The aperture of diffusion hole is designed as 8-12mm, the hole spacing is set as 30-50mm, and is uniformly distributed along the circumference of Venturi variable diameter flow channel 4, to ensure that the infrared gas sensor can uniformly contact the gas in the flow channel and avoid concentration measurement deviation caused by local gas retention. The internally hollow mounting seat is made of polytetrafluoroethylene material, which not only has corrosion resistance, but also can reduce the resistance of gas flow, to ensure the real-time performance of sensor detection. The hydrophobic air-permeable dustproof film 7 adopts PTFE microporous membrane, the membrane thickness is 0.1-0.2mm, and the micropore aperture is 0.2-0.5μm, which can not only block coal dust and water droplets from entering the sensor, but also ensure the rapid penetration of methane gas, and the edge of the membrane is sealed with epoxy resin and the inner wall of the diffusion hole, to prevent gas leakage from the gap between the membrane and the hole wall from affecting the measurement accuracy.

[0034] A temperature and pressure integrated sensor 8 is embeddedly installed in the straight section before the throat of Venturi variable diameter flow channel 4 or the expansion section after the throat, and the pressure sensing surface of the temperature and pressure integrated sensor 8 is flush with the inner wall of the flow channel.

[0035] Further, the installation position of the temperature and pressure integrated sensor 8 needs to meet the requirement of being 10-15 times the flow channel diameter away from the throat 10, for example, when the flow channel diameter is 50mm, the installation position is 500-750mm away from the throat, the gas flow field in this area is stable, and the interference of high-speed gas flow in the throat on pressure and temperature measurement can be avoided. The sensor is installed in an embedded manner, the gap between the shell and the inner wall of the flow channel is filled with high-temperature resistant sealing glue, the sealing glue has a temperature resistance range of-30-120℃, and sealing failure caused by temperature change is prevented. The flatness error between the pressure sensing surface and the inner wall of the flow channel is controlled to be within ±0.1mm, and local vortex caused by protrusions or depressions is avoided to affect the accuracy of pressure measurement.

[0036] A fine filter element 9 is arranged in the interior of the gas inlet interface 2 in a fitted manner, and the fine filter element 9 is used for efficiently removing large coal dust and water droplets in the gas. The fine filter element 9 adopts a structure of a metal framework plus a composite filter layer.

[0037] Further, the fine filter element 9 adopts a structure of a metal framework plus a composite filter layer, the metal framework is made of 304 stainless steel and serves as a support, and the composite filter layer comprises, from outside to inside, a nylon filter screen, an activated carbon fiber layer and a glass fiber membrane. The fine filter element 9 and the gas inlet interface 2 are connected in a buckle type, a sealing rubber ring is arranged on the outer side of the filter element, and it is ensured that the gas flows through the filter element.

[0038] The interior of the main shell 1 is provided with a connecting pipe 10, the connecting pipe 10 is located above the Venturi variable-diameter flow channel 4, one end of the connecting pipe 10 extends into the interior of the Venturi variable-diameter flow channel 4 and is connected with a two-way nozzle 12, the two-way nozzle 12 is provided with an electromagnetic valve in the interior, the other end of the connecting pipe 10 penetrates through the outer wall of one side of the main shell 1 and is connected with a high-pressure gas pipe 11, and the high-pressure gas pipe 11 is used for conveying a high-pressure gas source.

[0039] Further, the connecting pipe 10 is made of copper alloy and can withstand a pressure of more than 1.0MPa, so that the pipe is prevented from being broken due to impact of high-pressure gas. The spray angles of the two spray ports of the two-way nozzle 12 and the target surface are 45°, so that the high-pressure gas flow can accurately cover the sensitive area and will not damage the sensor. The electromagnetic valve is a mine intrinsic safety type and has an overcurrent protection function, so that a safety accident caused by short circuit is prevented. The connection between the high-pressure gas pipe 11 and the connecting pipe 10 adopts a quick connector, so that the connection can be completed within 10 seconds by one person without tools, and a one-way valve is arranged at the connector, so that when the high-pressure gas source is interrupted, the gas in the flow channel is prevented from entering the gas pipe in the reverse direction.

[0040] Further, the device installation process: first confirm that the downhole extraction pipeline valve is in the closed state, disconnect the pipeline flange at the installation location, prepare the installation tool, connect the air inlet interface 2 and the gas outlet interface 3 of the main shell 1 to the extraction pipeline through the flange, add an oil-resistant rubber gasket between the flanges, and fasten with bolts to ensure that the seal is leak-proof. Then connect one end of the high-pressure gas pipe 11 to the connecting pipe 10 of the device, and the other end to the downhole compressed air source. A pressure gauge is required to monitor the pressure. Then install the antenna of the communication module in the unobstructed area of the well to ensure stable signal, connect the intrinsically safe power supply, check the device indicator light, and the power light is green. The communication light is yellow and flickering, which is normal. Finally, slowly open the extraction pipeline valve and pass a small amount of gas. Apply soap water to the flange interface and observe if there are bubbles. If not, the seal is qualified. At the same time, start the self-cleaning module and check if the bidirectional nozzle 12 is working normally.

[0041] System debugging process: log in to the device control interface through the ground monitoring platform, configure basic parameters such as data acquisition frequency, self-cleaning period, warning threshold, initial frequency of ultrasonic probe, and initial window of filter, etc. Then pass standard gas into the device, compare the measured value of the infrared gas sensor with the standard value, correct the deviation through the concentration compensation algorithm, and calibrate the flow measurement value of the ultrasonic sensing probe 6 with a standard flowmeter. Send the "remote trigger self-cleaning" command from the ground monitoring platform, observe whether the electromagnetic valve of the device is started, and at the same time check whether the platform receives the "cleaning complete" feedback signal to ensure that the communication link is bidirectional and smooth.

[0042] Daily operation and maintenance: the device automatically performs the processes of pretreatment, parameter acquisition, data processing and uploading, and the ground platform displays the parameter curves in real time. The extraction volume statistical report is automatically generated every hour, and when the parameters exceed the limit, the platform triggers an audible and visual warning and sends a message to the management personnel containing "drilling hole number, abnormal parameters and abnormal time" etc.

[0043] If the concentration data fluctuates greatly, trigger the self-cleaning module remotely. If it is still abnormal after cleaning, arrange for downhole personnel to check whether the hydrophobic and breathable dustproof film 7 is blocked, whether the ultrasonic sensing probe 6 is damaged, whether the communication module antenna is offset, or whether the downhole ring network is faulty.

[0044] The present application provides a kind of gas extraction borehole multi-parameter monitoring system, including preprocessing module, multi-parameter sensing module, self-cleaning module, control processing module and communication module, preprocessing module passes through fine filter element 9 to filter the gas entering main casing 1, multi-parameter sensing module detects the multiple parameters of the gas flowing through venturi variable diameter flow channel 4 in real time by sensor, self-cleaning module is used to execute periodic or triggered cleaning action, which removes the impurities attached to the sensor sensitive element or the wall of venturi variable diameter flow channel 4 by high-pressure gas source, control processing module is electrically connected with multi-parameter sensing module and self-cleaning module respectively, for controlling the data acquisition and operation of multi-parameter sensing module and processing data using built-in adaptive algorithm, controlling the start of electromagnetic valve, communication module is electrically connected with control processing module, for sending the processed data to external monitoring system. The action of self-cleaning module is triggered by at least one of the following ways: timing trigger based on preset time period, trigger based on sensor data exceeding threshold value, or receiving remote instruction from external system. The adaptive algorithm built in control processing module includes: flow range adaptive sub-algorithm, for dynamically adjusting the transmission frequency and reception gain of ultrasonic sensing probe 6 according to historical flow data. Concentration compensation sub-algorithm, for real-time compensation of gas concentration reading according to temperature and pressure data. Filter parameter adaptive sub-algorithm, for dynamically adjusting the window size of digital filter according to flow rate change.

[0045] Further, the multi-parameter sensing module uses hardware clock synchronization plus data frame marking technology to ensure that the data acquisition time deviation of the ultrasonic sensing probe 6, infrared gas sensor and temperature and pressure integrated sensor 8 is ≤1ms. The analog signals output by the sensor are first processed by a signal conditioning circuit, which includes amplification, filtering and isolation functions, and then converted into digital signals by a 16-bit AD converter. The sampling frequency can be dynamically adjusted by the control processing module. High sampling frequency is used in high gas area, and low sampling frequency is used in low gas area to balance data accuracy and power consumption. At the same time, a data buffer area is provided in the module. When communication is interrupted, it can temporarily store monitoring data for 1 hour. After communication is restored, it automatically supplements transmission to avoid data loss.

[0046] The cleaning parameters of the self-cleaning module can be flexibly configured through the ground monitoring platform: the coal dust concentration underground can be adjusted to avoid the problem of damage to the sensor due to excessive pressure or incomplete cleaning due to low pressure.

[0047] The underground communication ring network interacts with the communication module for transmitting monitoring data. The ground monitoring center includes a server and a monitoring software platform. The server receives and displays, stores and analyzes real-time data uploaded from underground through the monitoring software platform, and intelligently evaluates and warns the drilling extraction effect. The monitoring software platform can issue control instructions to the specified multi-parameter adaptive monitoring device for remote parameter configuration or triggering of self-cleaning operation.

[0048] Further, the downhole communication ring network adopts a dual-link architecture of optical fiber as the main link and wireless as the auxiliary link, the optical fiber link adopts a mine-used explosion-proof optical fiber switch, supports ring network redundancy, when a certain section of optical fiber fails, data can be transmitted through the standby path, ensuring uninterrupted communication, the wireless link adopts LoRa wireless technology, which serves as a backup for the optical fiber link, when the optical fiber link fails and cannot be repaired for a short time, it automatically switches to the wireless link to transmit critical data, avoiding data interruption.

[0049] The working principle and use process of the application: the gas in the extraction pipeline enters the main shell 1 from the gas inlet interface 2, first flows through the fine filter element 9, filters out large particle coal dust and water droplets, avoids the subsequent flow channel and sensor from being blocked, and the pretreated gas enters the Venturi variable diameter flow channel 4, flows along the contraction section, throat and expansion section, and a stable flow field is formed at the throat, at this time, the ultrasonic sensing probe 6 symmetrically emits / receives ultrasonic waves, the gas flow causes the ultrasonic wave propagation time difference to change, and the control processing module calculates the flow rate according to the time difference, and then converts the flow rate in combination with the throat cross-sectional area of the Venturi variable diameter flow channel 4.

[0050] The infrared gas sensor contacts the gas through the diffusion hole, methane molecules absorb infrared rays of a specific wavelength, the sensor converts the absorption intensity into a concentration signal, and then corrects the accurate concentration value through a concentration compensation algorithm, and the temperature and pressure integrated sensor 8 directly collects the temperature and pressure of the gas in the flow channel, providing basic data for concentration and flow correction.

[0051] The control processing module optimizes data through an adaptive algorithm, uploads the processed flow, concentration, temperature, pressure and equipment state data to the downhole communication ring network through the communication module, and then transmits the data to the ground monitoring center through the ring network, when the timing period, parameter threshold value or remote instruction triggering condition is reached, the control processing module starts the electromagnetic valve, the high-pressure gas in the high-pressure gas pipe 11 is sprayed to the surface of the ultrasonic probe and the diffusion hole through the connecting pipe 10 and the bidirectional nozzle 12, and the attached coal dust and water vapor are removed, after cleaning, the electromagnetic valve is closed, and the device returns to normal monitoring.

[0052] Use process: the downhole personnel connect the device power supply and high-pressure gas source, the ground personnel confirm that the device is online on the monitoring platform, the state display is normal, and the data acquisition function is started. The ground personnel view the real-time parameters of each borehole through the platform, and focus on the cooperative change of flow and concentration, such as flow decrease but concentration increase, which may be borehole blockage, and needs to be checked in time, daily extraction effect evaluation report is generated, and drilling extraction efficiency is analyzed, such as low-efficiency borehole needs to adjust the extraction negative pressure. When the sensor data of a certain borehole is found to be abnormal, the ground personnel first remotely trigger the self-cleaning module, observe whether the data is restored, if not, issue parameter configuration instructions to adjust the ultrasonic probe frequency, and still abnormal, then arrange the downhole site to check.

[0053] When the fine filter element 9 or sensor needs to be replaced, first issue a stop command under the ground platform, the device stops data collection, the underground personnel close the extraction pipeline valve and high pressure gas source, disconnect the power supply and then maintain, after maintenance is completed, restart the device, the ground platform calibrates the data and then resumes operation.

[0054] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely divergences of the principles and spirit of the application and that numerous modifications, changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the application as defined by the appended claims and their equivalents.

Claims

1. A multi-parameter monitoring device for gas drainage boreholes, comprising a main housing (1), characterized in that, The main housing (1) is provided with an air inlet (2) and an air outlet (3) for connecting the extraction pipeline at both ends. A Venturi variable diameter channel (4) is provided inside the main housing (1). Symmetrically arranged mesh plates (5) are installed at the throat of the Venturi variable diameter channel (4). Ultrasonic sensing probes (6) are installed on the surfaces of the two sets of mesh plates (5) that are close to each other.

2. The multi-parameter monitoring device for gas drainage boreholes according to claim 1, characterized in that, The inner wall of the Venturi variable diameter channel (4) is provided with multiple sets of diffusion holes. An infrared gas sensor is fixed inside the multiple sets of diffusion holes through an internally hollow mounting base. A hydrophobic, breathable, and dustproof membrane (7) is installed at the inlet of the multiple sets of diffusion holes.

3. The multi-parameter monitoring device for gas drainage boreholes according to claim 1, characterized in that, The Venturi variable diameter flow channel (4) has a temperature and pressure integrated sensor (8) embedded in the straight section before the throat or the expansion section after the throat, and the pressure sensing surface of the temperature and pressure integrated sensor (8) is flush with the inner wall of the flow channel.

4. The multi-parameter monitoring device for gas drainage boreholes according to claim 1, characterized in that, The air intake port (2) is internally fitted with a fine filter element (9), which is used to efficiently remove large particles of coal dust and water droplets from the gas. The fine filter element (9) adopts a structure of metal skeleton plus composite filter layer.

5. The multi-parameter monitoring device for gas drainage boreholes according to claim 1, characterized in that, The main housing (1) is provided with a connecting pipe (10) inside, and the connecting pipe (10) is located above the Venturi variable diameter flow channel (4). One end of the connecting pipe (10) extends into the interior of the Venturi variable diameter flow channel (4) and is connected to a bidirectional nozzle (12). The bidirectional nozzle (12) is provided with a solenoid valve inside. The other end of the connecting pipe (10) passes through one side of the outer wall of the main housing (1) and is connected to a high-pressure air pipe (11). The high-pressure air pipe (11) is used to transport a high-pressure air source.

6. A multi-parameter monitoring system for gas drainage boreholes, applicable to the multi-parameter monitoring device for gas drainage boreholes as described in any one of claims 1-5, characterized in that, It includes a pretreatment module, a multi-parameter sensing module, a self-cleaning module, a control processing module, and a communication module. The pretreatment module filters the gas entering the main housing (1) through a fine filter element (9). The multi-parameter sensing module detects multiple parameters of the gas flowing through the Venturi variable diameter channel (4) in real time through sensors. The self-cleaning module is used to perform periodic or triggered cleaning actions. It removes impurities attached to the sensor sensitive element or the wall of the Venturi variable diameter channel (4) through a high-pressure gas source. The control processing module is electrically connected to the multi-parameter sensing module and the self-cleaning module respectively. It is used to control the data acquisition and operation of the multi-parameter sensing module and process the data using the built-in adaptive algorithm. It controls the start of the solenoid valve. The communication module is electrically connected to the control processing module and is used to send the processed data to the external monitoring system.

7. A multi-parameter monitoring system for gas drainage boreholes according to claim 6, characterized in that, The self-cleaning module is triggered by at least one of the following methods: timed triggering based on a preset time period, triggering based on sensor data exceeding a threshold, or triggering by receiving a remote command from an external system.

8. A multi-parameter monitoring system for gas drainage boreholes according to claim 6, characterized in that, The adaptive algorithm built into the control processing module includes: The flow range adaptive sub-algorithm is used to dynamically adjust the transmission frequency and receiving gain of the ultrasonic sensor probe (6) based on historical flow data. The concentration compensation sub-algorithm is used to compensate the gas concentration reading in real time based on temperature and pressure data; The adaptive sub-algorithm for filtering parameters is used to dynamically adjust the window size of the digital filter according to changes in flow velocity.

9. A multi-parameter monitoring system for gas drainage boreholes according to claim 6, characterized in that, Also includes: The underground communication ring network interacts with the communication module to transmit monitoring data; The ground monitoring center includes a server and a monitoring software platform. The server receives, displays, stores, and analyzes real-time data uploaded from downhole through the monitoring software platform, and provides intelligent evaluation and early warning of the drilling extraction effect.

10. A multi-parameter monitoring system for gas drainage boreholes according to claim 9, characterized in that, The monitoring software platform can send control commands to the designated multi-parameter adaptive monitoring device for remote parameter configuration or triggering self-cleaning operations.

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