Mine underground gas extraction drilling intelligent regulation and control method and device

Abstract

The present application relates to the technical field of coal mine underground gas extraction, in particular to a mine underground gas extraction drilling intelligent regulation method and device. The method comprises: S1: obtaining the gas concentration data of each drilling hole in the current coal seam to calculate the gas attenuation coefficient of the current coal seam; S2: calculating the predicted gas concentration at the future time based on the gas attenuation coefficient of the current coal seam; S3: calculating the predicted fluctuation range of each period in the future through the predicted gas concentration of the current coal seam at the future time; S4: based on the continuous real-time gas concentration data of the target drilling hole of the current coal seam, and calculating the average gas concentration of the target drilling hole in the current period; S5: comparing the average gas concentration of the target drilling hole in the current period with the predicted fluctuation range of the current period, evaluating the extraction state of the target drilling hole, and selecting the corresponding adjustment strategy to realize the valve adjustment of the target drilling hole. The present application can improve the accuracy and efficiency of drilling valve regulation in mine underground gas extraction.

Description

Technical Field

[0001] This invention relates to the field of underground gas extraction technology in coal mines, specifically to an intelligent control method and device for underground gas extraction boreholes in mines. Background Technology

[0002] In coal mine production, gas hazards pose a significant threat to safe production and the lives of personnel. Gas primarily exists within coal seams; when its concentration reaches the explosive limit and encounters an ignition source, it can trigger a violent explosion, causing serious consequences such as casualties, equipment damage, and production interruption. As a clean energy source, gas, if not properly extracted and utilized, not only wastes energy but also interferes with coal mining operations. Therefore, the core objective of underground gas extraction in coal mines is to effectively reduce the gas content and pressure in the coal seam, controlling it within a safe range to prevent gas accidents, ensure the safe and stable operation of coal mine production, and simultaneously achieve the resource utilization of gas, thereby improving the economic and environmental benefits of the coal mine.

[0003] In a gas drainage system, boreholes are the crucial channels connecting the coal seam and the drainage pipeline. Their purpose is to provide a flow path for gas in the coal seam, allowing it to smoothly enter the drainage pipeline from within the coal seam and then be extracted from the mine. Borehole valves are important control components in the gas drainage system, and their adjustment is primarily aimed at precisely controlling the flow and pressure of gas based on the dynamic changes in coal seam gas emission. In actual production, the amount of gas emitted from the coal seam is not constant but is affected by various factors, such as the advancement of the coal face and changes in geological structure. Properly adjusting the opening of the borehole valves allows the gas drainage system to maintain optimal operating conditions under different circumstances. Precise valve control improves the efficiency and stability of gas drainage, ensuring the safe and economical operation of coal mine production.

[0004] Currently, existing borehole valve control technologies have several shortcomings. On the one hand, many coal mines still use traditional manual control methods, relying on the experience and on-site judgment of operators to adjust valves. This method is greatly affected by human factors; different operators have varying levels of experience and judgment, making it difficult to guarantee the accuracy of valve adjustment. Moreover, manual control cannot monitor subtle changes in coal seam gas emission in real time, making timely adjustments difficult and prone to lag or over-adjustment. On the other hand, some coal mines have introduced automated control equipment, but these devices have relatively limited functions and lack in-depth analysis and prediction capabilities regarding coal seam gas emission patterns. They can only adjust based on preset fixed parameters and cannot dynamically adjust valve openings based on real-time data, making them unsuitable for the complex and ever-changing underground gas environment. Furthermore, existing technologies also lack in data processing and analysis, failing to fully utilize historical data and real-time information to optimize valve control strategies, resulting in poor valve control effects and impacting the overall performance and safety of the gas extraction system. Summary of the Invention

[0005] To address the shortcomings of the existing technologies, the technical problem to be solved by this invention is: how to provide an intelligent control method and device for underground gas drainage boreholes in mines, which evaluates the drainage status of the target borehole by comparing the real-time gas concentration of the borehole with the fluctuation range predicted in advance based on the gas attenuation coefficient of the coal seam, and selects the corresponding adjustment strategy to realize the valve adjustment of the borehole, thereby improving the accuracy and efficiency of borehole valve control in underground gas drainage in mines.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A method for intelligent control of underground gas drainage boreholes in mines, comprising:

[0008] S1: Obtain the gas concentration data of each borehole in the current coal seam and calculate the gas attenuation coefficient of the current coal seam;

[0009] S2: Calculate the predicted gas concentration at future times based on the current gas attenuation coefficient of the coal seam;

[0010] S3: Calculate the predicted fluctuation range for each future period based on the predicted gas concentration of the current coal seam at future times;

[0011] S4: Based on the continuous real-time gas concentration data of the target borehole in the current coal seam, calculate the average gas concentration of the target borehole in the current period;

[0012] S5: Compare the average gas concentration of the target borehole in the current cycle with the predicted fluctuation range of the current cycle to assess the extraction status of the target borehole, and select the corresponding adjustment strategy based on the extraction status to achieve valve adjustment of the target borehole.

[0013] Preferably, in step S1, the gas concentration data of each borehole in the current coal seam at each time is obtained; the gas attenuation coefficient model is solved by using the gas concentration data at each time through linear regression or nonlinear fitting to obtain the gas attenuation coefficient of the current coal seam.

[0014] The formula for the gas attenuation coefficient model is expressed as:

[0015] C t =C0×e -α×t×k ;

[0016] In the formula: C t C0 represents the initial gas concentration at time t in the current coal seam; α represents the gas attenuation coefficient of the current coal seam; t represents the time of gas initiation; and k represents the correction coefficient.

[0017] Preferably, in step S2, the predicted gas concentration at future times is calculated using the following formula:

[0018]

[0019] In the formula: P t C0 represents the predicted gas concentration of the current coal seam at a future time t; α represents the initial gas extraction concentration; t0 represents the gas attenuation coefficient of the current coal seam; k represents the current extraction time; and k represents the correction coefficient.

[0020] Preferably, in step S3, the predicted fluctuation range includes the predicted middle track, the predicted upper track, and the predicted lower track;

[0021] 1) Predicting the middle track

[0022] Calculate the moving average of the predicted gas concentration within this period as the predicted midline of the fluctuation range;

[0023] The formula is expressed as:

[0024]

[0025] Where: MID t The predicted midline represents the predicted fluctuation range; N represents the number of days in a cycle; P i The predicted gas concentration at time i within the period;

[0026] 2) Predict the upper rail

[0027] The formula is expressed as:

[0028] UP t =MID t +K×STD t ;

[0029]

[0030] In the formula: UP t The upper bound of the predicted fluctuation range is indicated by STD. t The standard deviation of the predicted gas concentration within the period is represented by K; K represents the fluctuation coefficient.

[0031] 3) Predict the lower rail

[0032] The formula is expressed as:

[0033] DN t =MID t -K×STD t ;

[0034] Where: DN t The lower bound of the predicted fluctuation range.

[0035] Preferably, in step S4, the average gas concentration of the target borehole in the current cycle is calculated using the following formula:

[0036]

[0037] Where: MA t M represents the average gas concentration of the target borehole in the current cycle; t This represents the real-time gas concentration data of the target borehole at time t; M i This represents the real-time gas concentration data at time i within the current cycle; N represents the number of days in a cycle.

[0038] Preferably, in step S5, the extraction status of the target borehole is evaluated according to the following rules:

[0039] 1) When DN is satisfied t <MA t <UP t , and MA t With MID t If the trends match, the extraction status of the target borehole is judged to be normal and stable.

[0040] 2) When MA is satisfied t Below MID t MA for x consecutive days or more t <DN t If so, the extraction state of the target borehole is determined to be in a decay state;

[0041] 3) When MA is satisfied t Higher than MID t MA for x consecutive days or more t >UP t If so, the extraction status of the target borehole is determined to be abnormally active.

[0042] 4) When MA is satisfied t Below MID t and STD t If the value is less than the preset value, the extraction status of the target borehole is determined to be inefficient.

[0043] Preferably, in step S5, the adjustment strategy includes:

[0044] 1) For target boreholes in a normal and stable state, the adjustment strategy includes: maintaining the current valve opening and keeping the negative pressure stable;

[0045] 2) For target boreholes in the decay state, the adjustment strategy includes: gradually reducing the valve opening; when the borehole pressure is <-13kPa, stop reducing the valve opening and maintain the pressure ≥-13kPa;

[0046] 2) For target boreholes in an abnormally active state, the adjustment strategy includes: gradually increasing the valve opening until the pressure is ≤-35kPa or the opening reaches 100%;

[0047] 4) For target boreholes operating at low efficiency, adjustment strategies include: gradually reducing the valve opening; if MA t If the value is less than 0.5%, then close the valve.

[0048] Preferably, in step S5, the valve adjustment is assisted by the oxygen concentration of the target borehole: when the extraction state of the target borehole is in a decaying state and the oxygen concentration shows an increasing trend, it indicates that the borehole seal has failed, and the valve opening is reduced more quickly until the oxygen concentration drops below the safe target value.

[0049] Preferably, in step S5, the valve adjustment is assisted by the pressure of the target borehole: when the pressure of the target borehole gradually decreases from negative pressure, or even gradually becomes positive pressure, it indicates that there is an abnormal gas outburst, and the valve opening is immediately increased to the maximum and an alarm is triggered.

[0050] A smart control device for underground gas drainage boreholes in mines, implemented based on a smart control method for underground gas drainage boreholes in mines, includes:

[0051] 1) Drilling comprehensive parameter measuring instrument, including:

[0052] The sensor module is used to collect characteristic parameters of the borehole, including gas concentration, carbon monoxide concentration, oxygen concentration, pressure and / or flow rate. Different borehole parameters are collected in time by switching the gas acquisition path, and the data is collected centrally.

[0053] The data processing module is used to acquire gas concentration data of each borehole in the current coal seam and calculate the gas attenuation coefficient of the current coal seam; calculate the predicted gas concentration at future times based on the gas attenuation coefficient of the current coal seam; calculate the predicted fluctuation range of each future period based on the predicted gas concentration of the current coal seam at future times; calculate the average gas concentration of the target borehole in the current period based on the continuous real-time gas concentration data of the target borehole in the current coal seam; compare the average gas concentration of the target borehole in the current period with the predicted fluctuation range of the current period to evaluate the extraction status of the target borehole, and select the corresponding adjustment strategy according to the extraction status.

[0054] 2) Distributed wireless valve controller, intrinsically safe valve, used to perform valve regulation in drilling based on the regulation strategy selected by the data processing module.

[0055] Compared with existing technologies, the intelligent control method and device for underground gas drainage boreholes in mines of this invention have the following advantages:

[0056] This invention calculates the gas attenuation coefficient by acquiring gas concentration data from various boreholes in the current coal seam. Since the gas occurrence and emission characteristics vary across different areas of the coal seam, comprehensively collecting gas concentration data from each borehole accurately reflects the actual gas condition of the current coal seam. The gas attenuation coefficient calculated based on this data fully considers the overall complexity and non-uniformity of the coal seam, ensuring high accuracy in subsequent calculations to predict future gas concentrations, predict fluctuation ranges, and assess the extraction status of target boreholes. This lays the foundation for precise valve regulation, thereby improving the accuracy of borehole valve control throughout the gas extraction process.

[0057] This invention calculates the predicted gas concentration at future times based on the current gas attenuation coefficient of the coal seam, and further calculates the predicted fluctuation range for each future cycle. Existing methods lack the ability to predict future gas changes, leading to delayed and frequent adjustments. This invention, by calculating and predicting gas concentration and fluctuation range, can anticipate gas change trends in advance. When facing complex and variable underground gas environments, it enables rapid and targeted adjustments to borehole valves, avoiding delays and confusion caused by ad-hoc responses, shortening the adjustment cycle, and thus improving the overall gas extraction system's response speed to gas changes and the efficiency of borehole valve adjustments.

[0058] This invention calculates the current periodic average gas concentration based on continuous real-time gas concentration data from the target borehole, compares it with the predicted fluctuation range to assess the extraction status, and selects an adjustment strategy to regulate the valves in the target borehole. Continuous real-time data comprehensively and dynamically reflects the gas changes in the target borehole. Simultaneously, comparing the average gas concentration with the predicted fluctuation range accurately determines whether the current extraction status is normal and stable, declining, abnormally active, or inefficient. Based on the accurate extraction status assessment, the corresponding adjustment strategy is selected, ensuring a high degree of match between valve regulation and actual needs, avoiding over- or under-regulation, thereby further improving the accuracy of borehole valve regulation and ensuring the stable operation of the gas extraction system. Attached Figure Description

[0059] To make the objectives, technical solutions, and advantages of the invention clearer, the invention will now be described in further detail with reference to the accompanying drawings, wherein:

[0060] Figure 1 A flowchart for an intelligent control method for underground gas extraction boreholes in mines.

[0061] Figure 2 This is a schematic diagram of an intelligent control device for underground gas extraction boreholes in a mine. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but only to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0063] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product is in use. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. In addition, the terms "horizontal," "vertical," etc., do not mean that the component is required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0064] The following detailed explanation illustrates the specific implementation methods:

[0065] Example 1:

[0066] This embodiment discloses an intelligent control method for underground gas extraction boreholes in mines.

[0067] like Figure 1 As shown, a method for intelligent control of underground gas drainage boreholes in mines includes:

[0068] S1: Obtain the gas concentration data of each borehole in the current coal seam and calculate the gas attenuation coefficient of the current coal seam;

[0069] S2: Calculate the predicted gas concentration at future times based on the current gas attenuation coefficient of the coal seam;

[0070] S3: Calculate the predicted fluctuation range for each future period based on the predicted gas concentration of the current coal seam at future times;

[0071] S4: Based on the continuous real-time gas concentration data of the target borehole in the current coal seam, calculate the average gas concentration of the target borehole in the current period;

[0072] S5: Compare the average gas concentration of the target borehole in the current cycle with the predicted fluctuation range of the current cycle to assess the extraction status of the target borehole, and select the corresponding adjustment strategy based on the extraction status to achieve valve adjustment of the target borehole.

[0073] This invention calculates the gas attenuation coefficient by acquiring gas concentration data from various boreholes in the current coal seam. Since the gas occurrence and emission characteristics vary across different areas of the coal seam, comprehensively collecting gas concentration data from each borehole accurately reflects the actual gas condition of the current coal seam. The gas attenuation coefficient calculated based on this data fully considers the overall complexity and non-uniformity of the coal seam, ensuring high accuracy in subsequent calculations to predict future gas concentrations, predict fluctuation ranges, and assess the extraction status of target boreholes. This lays the foundation for precise valve regulation, thereby improving the accuracy of borehole valve control throughout the gas extraction process.

[0074] This invention calculates the predicted gas concentration at future times based on the current gas attenuation coefficient of the coal seam, and further calculates the predicted fluctuation range for each future cycle. Existing methods lack the ability to predict future gas changes, leading to delayed and frequent adjustments. This invention, by calculating and predicting gas concentration and fluctuation range, can anticipate gas change trends in advance. When facing complex and variable underground gas environments, it enables rapid and targeted adjustments to borehole valves, avoiding delays and confusion caused by ad-hoc responses, shortening the adjustment cycle, and thus improving the overall gas extraction system's response speed to gas changes and the efficiency of borehole valve adjustments.

[0075] This invention calculates the current periodic average gas concentration based on continuous real-time gas concentration data from the target borehole, compares it with the predicted fluctuation range to assess the extraction status, and selects an adjustment strategy to regulate the valves in the target borehole. Continuous real-time data comprehensively and dynamically reflects the gas changes in the target borehole. Simultaneously, comparing the average gas concentration with the predicted fluctuation range accurately determines whether the current extraction status is normal and stable, declining, abnormally active, or inefficient. Based on the accurate extraction status assessment, the corresponding adjustment strategy is selected, ensuring a high degree of match between valve regulation and actual needs, avoiding over- or under-regulation, thereby further improving the accuracy of borehole valve regulation and ensuring the stable operation of the gas extraction system.

[0076] To better illustrate the technical solution of the present invention, this embodiment is described in the following parts.

[0077] I. Gas Attenuation Coefficient

[0078] In the specific implementation process, the gas concentration data of each borehole in the current coal seam at each time is obtained; the gas attenuation coefficient model is solved using the gas concentration data at each time through linear regression or nonlinear fitting (such as the least squares method) to obtain the gas attenuation coefficient of the current coal seam.

[0079] The formula for the gas attenuation coefficient model is expressed as:

[0080] C t =C0×e -α×t×k ;

[0081] In the formula: C t This represents the gas concentration of the current coal seam at time t (i.e., day t); C0 represents the initial gas extraction concentration; α represents the gas attenuation coefficient (d-1) of the current coal seam; t represents the extraction start time (i.e., day t); k represents the correction coefficient, which is adjusted according to the geological conditions of the coal seam. The correction coefficient k needs to be calibrated based on parameters such as coal seam permeability and borehole diameter.

[0082] II. Predicting Gas Concentration

[0083] In the specific implementation process, the predicted concentration for the next T days (e.g., T=20) is calculated based on the coal seam reference attenuation coefficient α.

[0084] Specifically, the predicted gas concentration at future times is calculated using the following formula:

[0085]

[0086] In the formula: P t This represents the predicted gas concentration of the current coal seam at a future time t (i.e., day t), where t = 1, 2, ..., T represents the future day t; C0 represents the initial gas extraction concentration; α represents the gas attenuation coefficient of the current coal seam; t0 represents the current extraction time; and k represents the correction coefficient.

[0087] III. Predicted Fluctuation Range

[0088] In practice, the predicted fluctuation range includes the predicted middle track, the predicted upper track, and the predicted lower track.

[0089] 1) Predicting the middle track

[0090] Calculate the moving average of the predicted gas concentration within this period (e.g., N=20) as the predicted midpoint of the fluctuation range;

[0091] The formula is expressed as:

[0092]

[0093] Where: MID t The predicted midline represents the predicted fluctuation range; N represents the number of days in a cycle; Pi This represents the predicted gas concentration at time i (i.e., day i) within the period;

[0094] Calculate P within the same period (N days) window t The standard deviation reflects the degree of volatility:

[0095]

[0096] 2) Predict the upper rail (UP)

[0097] The formula is expressed as:

[0098] UP t =MID t +K×STD t ;

[0099] In the formula: UP t The upper bound of the predicted fluctuation range is represented by STD. t It represents the standard deviation of the predicted gas concentration within the period; K represents the fluctuation coefficient, which is usually taken as 2-3, reflecting the confidence interval; the fluctuation coefficient K needs to be verified by historical data to ensure that it covers more than 95% of normal fluctuations.

[0100] 3) Predict the lower rail (DN)

[0101] The formula is expressed as:

[0102] DN t =MID t -K×STD t ;

[0103] Where: DN t The lower bound of the predicted fluctuation range.

[0104] IV. Average Gas Concentration

[0105] In the specific implementation process, the daily measured methane concentration M is continuously collected. t (%CH4), calculate the (N-day) moving average of the target borehole over the same period as the predicted mid-track. The average gas concentration in the current period is calculated using the following formula:

[0106]

[0107] Where: MA t M represents the average gas concentration of the target borehole in the current cycle; t This represents the real-time gas concentration data of the target borehole at time t (i.e., day t); M i This represents the real-time gas concentration data at time i (i.e., day i) within the current cycle; N represents the number of days in a cycle.

[0108] V. Evaluation of Sampling Status

[0109] In the specific implementation process, by comparing MA t With MID t UP t DN t The relationship between the data and the trend / fluctuation characteristics is used to evaluate the extraction status and guide valve adjustment. Status evaluation should incorporate multi-day trends (e.g., three consecutive days) to avoid interference from occasional data.

[0110] Specifically, the extraction status of the target borehole is assessed using the following rules:

[0111] 1) When DN is satisfied t <MA t <UP t , and MA t With MID t If the trends are consistent (e.g., both are slowly decreasing), then the extraction state of the target borehole is judged to be a normal and stable state.

[0112] 2) When MA is satisfied t Persistently below MID t MA for x consecutive days or more t <DN t If so, the extraction state of the target borehole is determined to be in a decay state;

[0113] 3) When MA is satisfied t consistently higher than MID t MA for x consecutive days or more t >UP t If so, the extraction status of the target borehole is determined to be abnormally active.

[0114] 4) When MA is satisfied t Persistently below MID t and STD t If the fluctuation is less than 0.5% (narrowing), the target borehole is judged to be inefficient in terms of extraction.

[0115] Specifically, the adjustment strategies include:

[0116] 1) For target boreholes in a normal and stable state, the adjustment strategy includes: maintaining the current valve opening and keeping the negative pressure stable;

[0117] 2) For target boreholes in the decay state, the adjustment strategy includes: gradually reducing the valve opening (each step is 50% of the maximum adjustable value; for example, if the maximum adjustable value is 80%, the first step is adjusted to 40%, the second step is adjusted to 20%, and so on); when the borehole pressure is <-13kPa, stop reducing the valve opening and maintain the pressure ≥-13kPa.

[0118] 2) For target boreholes in an abnormally active state, the adjustment strategy includes: gradually increasing the valve opening (each step is 50% of the maximum adjustable value); until the pressure is ≤-35kPa or the opening reaches 100%, and then quickly pump out the gas;

[0119] 4) For target boreholes operating at low efficiency, adjustment strategies include: gradually reducing the valve opening; if (MA t <0.5%)CH4, close the valve, and allocate negative pressure resources to efficient drilling.

[0120] VI. Multi-parameter fusion decision-making

[0121] In practice, in addition to gas concentration, comprehensive control is carried out by combining oxygen concentration (to determine borehole sealing), pressure (to determine abnormal outbursts), and flow rate (to determine extraction efficiency).

[0122] Specifically, valve adjustment is assisted by the oxygen concentration of the target borehole: when the extraction state of the target borehole is in a decaying state and the oxygen concentration shows an increasing trend (e.g., from 6% to 16%), it indicates that the borehole seal has failed (air has entered), and the valve opening needs to be reduced more quickly (each adjustment step is 70% of the maximum adjustable value) until the oxygen concentration drops below 12% (the safe target value).

[0123] Specifically, valve adjustment is assisted by the pressure of the target borehole: when the pressure of the target borehole gradually decreases from negative pressure, or even gradually becomes positive pressure (such as gradually changing from -13kPa to close to 0 or positive pressure), it indicates that there is an abnormal gas outburst (such as a precursor to a coal and gas outburst). Immediately increase the valve opening to the maximum (100%) and trigger an alarm (notify the ground monitoring center).

[0124] VII. Feedback Adjustment and Iterative Optimization

[0125] In practice, after the valve controller executes the control command, the centralized monitoring unit collects real-time feedback on valve opening (e.g., from 60% to 50%) and parameter changes (e.g., gas concentration decreasing from 0.8% to 0.6%) to determine whether the control target has been achieved (e.g., under decay conditions, the moving average of gas concentration returns to the MID). t If the target value is not reached (nearby); if not, continue iterative adjustments (such as reducing the valve opening to 40% again) until the parameters stabilize within a safe range.

[0126] Example 2:

[0127] This embodiment discloses an intelligent control device for underground gas extraction boreholes in mines, which is implemented based on the intelligent control method for underground gas extraction boreholes in mines described in Embodiment 1.

[0128] like Figure 2 As shown, an intelligent control device for underground gas drainage boreholes in mines includes:

[0129] 1) The borehole comprehensive parameter measuring instrument collects different borehole parameters in a time-sharing manner by switching the gas acquisition path, and centrally regulates the valves, reducing the investment cost of drilling site equipment. Each gas path channel of the borehole comprehensive parameter measuring instrument is equipped with a water filter device. After the test is completed, the gas path is adjusted, and the water is backwashed using the negative pressure of the borehole to ensure the normal operation of the testing gas path. The borehole comprehensive parameter measuring instrument measures borehole gas concentration, oxygen concentration, relative pressure, ambient atmospheric pressure, flow rate, flow velocity, carbon monoxide, and oxygen parameters, and evaluates different borehole conditions based on the different parameter change trends. The borehole comprehensive parameter measuring instrument communicates with the wireless valve controller wirelessly, collects the opening degree of the wireless valve controller, and sends control commands to the wireless valve controller.

[0130] A comprehensive borehole parameter measuring instrument, including:

[0131] The sensor module is used to collect characteristic parameters of the borehole, including but not limited to data such as gas concentration, carbon monoxide concentration, oxygen concentration, pressure, and flow rate. It collects different borehole parameters in a time-sharing manner by switching the gas acquisition path and collects data centrally.

[0132] The sensor module integrates a gas concentration sensor (0-100% CH4), an oxygen concentration sensor (0-25% O2), a carbon monoxide sensor (0-2000ppm CO), a pressure sensor (-100kPa~100kPa), and a flow sensor (0-350m³ / h). 3 A flow rate sensor (0-30 m / s) enables simultaneous acquisition of multiple parameters.

[0133] The gas path system is used to adopt a time-sharing acquisition mode (switching gas paths via solenoid valves to sequentially acquire gas parameters from each borehole). Each gas path channel has a built-in water filter (to prevent water from entering the sensor from the well). After the detection is completed, the gas path is flushed in reverse using the borehole negative pressure (the direction of the gas path is adjusted by solenoid valves to blow away the water and coal dust on the filter device) to ensure that the gas path is unobstructed.

[0134] The data processing module is used to acquire gas concentration data of each borehole in the current coal seam and calculate the gas attenuation coefficient of the current coal seam; calculate the predicted gas concentration at future times based on the gas attenuation coefficient of the current coal seam; calculate the predicted fluctuation range of each future period based on the predicted gas concentration of the current coal seam at future times; calculate the average gas concentration of the target borehole in the current period based on the continuous real-time gas concentration data of the target borehole in the current coal seam; compare the average gas concentration of the target borehole in the current period with the predicted fluctuation range of the current period to evaluate the extraction status of the target borehole, and select the corresponding adjustment strategy according to the extraction status.

[0135] The data processing module has a built-in microcontroller (such as STM32) to perform the following functions:

[0136] (1) Calculation of coal seam gas attenuation coefficient: Record the initial extraction concentration, extraction time and real-time concentration, and calculate the coal seam gas attenuation characteristics using the formula Ct=C0·e-λt+k.

[0137] (2) Prediction of expected concentration fluctuation range: Based on the attenuation coefficient, calculate the expected gas concentration for the next N days (e.g., 20 days), and calculate the N-day simple moving average (MID_t = SMA(N,P_t)) and standard deviation (STD_t = STD(N,P_t)) to obtain the predicted fluctuation range;

[0138] (3) Data processing: Real-time gas concentration (M_t) is collected, and the N-day measured moving average (MA_t=SMA(N,M_t)) is calculated for comparison with the expected fluctuation range.

[0139] 2) Distributed wireless valve controller, intrinsically safe valve, can be electric or pneumatic valve, can be battery powered or wired powered, supports opening degree monitoring feedback, used to perform valve regulation in drilling based on the regulation strategy selected by the data processing module.

[0140] The wireless valve controller employs a hybrid electrical-electric drive system. It connects to the downhole compressed air pipe for air supply to drive the pneumatic actuator. The air supply is regulated via a forward and reverse air path control circuit, which in turn drives the pneumatic actuator to adjust the valve opening. The wireless valve controller outputs the opening signal through an angle feedback mechanism and a data acquisition circuit. The wireless valve controller offers multiple control modes: remote control, manual control, and automatic control. Remote control is normally achieved through automatic control by the borehole comprehensive parameter measuring instrument. In case of automatic control failure, remote control can be achieved via Bluetooth connection to a data collection app. Manual control allows for quick switching of the wireless valve controller's air path and the controller's mechanical structure to manual mode in case of power or gas outages, using the valve body handwheel to adjust the valve. The borehole comprehensive parameter measuring instrument records the initial extraction concentration and extraction time, and uses this data to calculate the coal seam gas attenuation coefficient.

[0141] The borehole parameter measuring instrument can calculate the expected concentration fluctuation range of a borehole over time. The borehole comprehensive parameter measuring instrument can record data changes over time and calculate the measured moving average. By comparing the measured moving average with the expected fluctuation range, the borehole comprehensive parameter measuring instrument evaluates the borehole extraction status. Based on different borehole conditions and the current opening status feedback from the valve controller, the borehole comprehensive parameter measuring instrument calculates control values ​​and sends control commands to the valves. The borehole comprehensive parameter measuring instrument adjusts the valves based on intermediate values, simultaneously detecting the trend of target parameter changes until the control objective is achieved.

[0142] Distributed wireless valve controller, including:

[0143] Drive module: It adopts a gas-electric hybrid drive (connected to the downhole compressed air pipe (0.4-0.6MPa) to drive the pneumatic actuator, and adjusts the air supply direction through the forward and reverse air path control circuit to realize valve opening adjustment); the electrical part is used to control the air path switching (such as solenoid valve control) to ensure smooth drive.

[0144] Valve opening feedback module: Built-in angle sensor (accuracy ±1°) to detect valve opening (0-100%) in real time and feed the signal back to the centralized monitoring unit.

[0145] Control modes: Supports three control modes:

[0146] (1) Automatic control (default mode): The centralized monitoring unit automatically sends control commands based on the drilling status (such as normal, decay, abnormally active).

[0147] (2) Remote control: When automatic control fails, manually send control commands by connecting to a mobile APP or host computer via Bluetooth / LoRa communication;

[0148] (3) Manual control: In case of extreme situations such as power failure or gas failure, the valve can be switched to manual mode through a mechanical switching mechanism (such as a handle), and the opening can be adjusted by handwheel (to ensure controllability under extreme conditions).

[0149] 3) Data transmission and processing system

[0150] Communication method: LoRa wireless communication (transmission distance ≥ 400m, suitable for long-distance transmission in underground wells) is used to realize data transmission between the centralized monitoring unit and the distributed valve controller; Bluetooth communication (short-range emergency control) is used between the mobile APP and the valve controller.

[0151] Host computer software: Installed at the ground monitoring center, it performs the following functions:

[0152] (1) Status display: Real-time display of parameters such as gas concentration, oxygen concentration, carbon monoxide concentration, pressure, flow rate, and valve opening for each borehole;

[0153] (2) Sending control instructions: Based on the decision results of the centralized monitoring unit, send opening adjustment instructions to the valve controller (such as "adjust the opening of the borehole 1 valve to 50%).

[0154] (3) Historical data storage: Store parameter data for more than one year for analysis of borehole extraction trends (such as decay rate and abnormal event retrospective).

[0155] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A method for intelligent control of underground gas drainage boreholes in mines, characterized in that, include: S1: Obtain the gas concentration data of each borehole in the current coal seam and calculate the gas attenuation coefficient of the current coal seam; In step S1, the gas concentration data of each borehole in the current coal seam at each time is obtained; the gas attenuation coefficient model is solved by using the gas concentration data at each time through linear regression or nonlinear fitting to obtain the gas attenuation coefficient of the current coal seam. The formula for the gas attenuation coefficient model is expressed as: ； In the formula: Indicates the current coal seam at time [time]. That is, the first The daily gas concentration; Indicates the initial gas concentration; This represents the gas attenuation coefficient of the current coal seam; Indicates the moment of receiving / drawing; Indicates the correction factor; S2: Calculate the predicted gas concentration at future times based on the current gas attenuation coefficient of the coal seam; In step S2, the predicted gas concentration at future times is calculated using the following formula: ； In the formula: Indicates the current coal seam at a future time. That is, the future Predicted methane concentration for the day; Indicates the initial gas concentration; This represents the gas attenuation coefficient of the current coal seam; Indicates the current drawing time; Indicates the correction factor; S3: Calculate the predicted fluctuation range for each future period based on the predicted gas concentration of the current coal seam at future times; In step S3, the predicted fluctuation range includes the predicted middle rail, the predicted upper rail, and the predicted lower rail; 1) Predicting the middle track The moving average of the predicted gas concentration within the calculation period is used as the predicted midline of the fluctuation range. The formula is expressed as: ； In the formula: The middle track of the predicted fluctuation range; Indicates the number of days in a cycle; Indicates the time within the period That is, the first Predicted methane concentration for the day; 2) Predict the upper rail The formula is expressed as: ； ； In the formula: The upper bound of the predicted fluctuation range; This represents the standard deviation of the predicted gas concentration within the period. Indicates the volatility coefficient; 3) Predict the lower rail The formula is expressed as: ； In the formula: The lower bound of the predicted fluctuation range; S4: Based on the continuous real-time gas concentration data of the target borehole in the current coal seam, calculate the average gas concentration of the target borehole in the current period; In step S4, the average gas concentration of the target borehole in the current cycle is calculated using the following formula: ； In the formula: This indicates the average gas concentration in the target borehole during the current cycle; Indicates the target borehole at time That is, the first Real-time gas concentration data for the day; Indicates the time within the current period That is, the first Real-time gas concentration data for the day; Indicates the number of days in a cycle; S5: Compare the average gas concentration of the target borehole in the current cycle with the predicted fluctuation range of the current cycle to assess the extraction status of the target borehole, and select the corresponding adjustment strategy based on the extraction status to achieve valve adjustment of the target borehole.

2. The intelligent control method for underground gas drainage boreholes in mines as described in claim 1, characterized in that: In step S5, the extraction status of the target borehole is evaluated according to the following rules: 1) When satisfied ,and and If the trends match, the extraction status of the target borehole is judged to be normal and stable. 2) When satisfied Below and continuous Days and above If so, the extraction state of the target borehole is determined to be in a decay state; 3) When satisfied Higher than and continuous Days and above If so, the extraction status of the target borehole is determined to be abnormally active. 4) When satisfied Below ,and If the preset value is used, the extraction status of the target borehole is determined to be inefficient.

3. The intelligent control method for underground gas drainage boreholes in mines as described in claim 2, characterized in that: In step S5, the adjustment strategy includes: 1) For target boreholes in a normal and stable state, the adjustment strategy includes: maintaining the current valve opening and keeping the negative pressure stable; 2) For target boreholes in the decay state, the adjustment strategy includes: gradually reducing the valve opening; when the borehole pressure is <-13kPa, stop reducing the valve opening and maintain the pressure ≥-13kPa; 3) For target boreholes in an abnormally active state, the adjustment strategy includes: gradually increasing the valve opening until the pressure is ≤-35kPa or the opening reaches 100%; 4) For target boreholes operating at low efficiency, adjustment strategies include: gradually reducing the valve opening; if Then close the valve.

4. The intelligent control method for underground gas drainage boreholes in mines as described in claim 3, characterized in that: In step S5, the valve is adjusted in conjunction with the oxygen concentration of the target borehole: when the extraction state of the target borehole is in a decaying state and the oxygen concentration shows an increasing trend, it indicates that the borehole seal has failed, so the valve opening is reduced more quickly until the oxygen concentration drops below the safe target value.

5. The intelligent control method for underground gas drainage boreholes in mines as described in claim 3, characterized in that: In step S5, the valve is adjusted in conjunction with the pressure of the target borehole: when the pressure of the target borehole gradually decreases from negative pressure, or even gradually becomes positive pressure, it indicates that there is an abnormal gas outburst. The valve opening is immediately increased to the maximum and an alarm is triggered.

6. An intelligent control device for underground gas drainage boreholes in mines, characterized in that: The implementation of the intelligent control method for underground gas drainage boreholes in mines as described in claim 1 includes: 1) Drilling comprehensive parameter measuring instrument, including: The sensor module is used to collect characteristic parameters of the borehole, including gas concentration, carbon monoxide concentration, oxygen concentration, pressure and / or flow rate. Different borehole parameters are collected in time by switching the gas acquisition path, and the data is collected centrally. The data processing module is used to acquire gas concentration data of each borehole in the current coal seam and calculate the gas attenuation coefficient of the current coal seam; calculate the predicted gas concentration at future times based on the gas attenuation coefficient of the current coal seam; calculate the predicted fluctuation range of each future period based on the predicted gas concentration of the current coal seam at future times; calculate the average gas concentration of the target borehole in the current period based on the continuous real-time gas concentration data of the target borehole in the current coal seam; compare the average gas concentration of the target borehole in the current period with the predicted fluctuation range of the current period to evaluate the extraction status of the target borehole, and select the corresponding adjustment strategy according to the extraction status. 2) Distributed wireless valve controller, intrinsically safe valve, used to perform valve regulation in drilling based on the regulation strategy selected by the data processing module.

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