Gas coordinated control method in upper corner of a stoping face

Abstract

The application discloses a kind of upper corner gas coordinated management methods of drawing face, belong to coal mine safety technical field;The method comprises: obtaining the source of the upper corner and the evolution of gas accumulation and associated area and associated risk related multi-source physical field parameters;Determine the source characteristics of the upper corner gas accumulation based on multi-source physical field parameters;According to the source characteristics determined, dynamically adjust the running state of the first negative pressure execution end and the second negative pressure execution end, wherein the first negative pressure execution end preferentially intercepts roof fissure gas, and the second negative pressure execution end preferentially extracts and discharges goaf gas;Different source gas is realized by differential adjustment The coordinated management of different sources;The application solves the problem of mismatch between existing technology management measures and gas source conditions through source identification and double execution end adaptive control, improves the pertinence and efficiency of gas management, simultaneously gas control and environmental risk constraint are included in the same control logic, realize the coordinated prevention and control of gas overrun, low oxygen accumulation and residual coal oxidation.

Description

Technical Field

[0001] This invention relates to the field of coal mine safety technology, specifically to a method for the coordinated control of gas in the upper corner of a longwall face. Background Technology

[0002] The upper corner of the longwall face is one of the most dangerous areas in coal mines where gas is most likely to accumulate and exceed limits. Because the upper corner is located in the vortex zone at the junction of the working face and the goaf, airflow is difficult to reach it effectively. Gas from leaks in the goaf, depressurized gas from roof fissures, and locally trapped gas can easily accumulate here, forming a high-risk area for gas concentration, which seriously threatens the safe production of the mine.

[0003] Currently, methods for controlling excessive gas levels in the upper corner of a working face often employ a combination of measures, including goaf drainage via buried pipes, high-level borehole drainage, roadway drainage, and local ventilation control. For example, Chinese invention patent CN103670499B discloses a comprehensive method for controlling excessive gas levels in the upper corner of a working face. This method integrates goaf gas drainage, leakage control, local airflow dilution, and roof caving for pressure relief to synergistically manage both normally emerging and abnormally accumulated gas. Its core technology lies in reducing the gas concentration in the goaf and upper corner area through the combined arrangement of drainage and ventilation measures, thereby improving airflow conditions in the upper corner.

[0004] However, the existing technologies have the following shortcomings: During the mining process, the actual source of gas in the upper corner is dynamic. The proportions of roof fissure gas, gas carried by leaks in the goaf, and locally trapped gas vary at different stages of advancement and under different operating conditions. The aforementioned methods fail to identify the source of upper corner gas using multiple parameters, and cannot coordinate and adaptively control the operating parameters of the extraction and drainage circuits based on changes in the main controlling source. If fixed extraction parameters and remediation measures are consistently used, a mismatch in the layout between the extraction area of ​​the high-level borehole and the drainage area of ​​the buried pipe in the goaf can easily occur, leading to decreased extraction efficiency, increased risk of local gas accumulation, and difficulty in ensuring the targetedness and efficiency of remediation. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for the coordinated control of gas in the upper corner of a longwall mining face.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This application provides a method for the coordinated control of gas in the upper corner of a longwall face, including: Acquire monitoring data of the upper corner and associated areas, wherein the monitoring data are multi-source physical field parameters related to gas accumulation and associated risk evolution in the upper corner; Based on the multi-source physical field parameters, the source characteristics of gas accumulation in the upper corner are determined; Based on the determined source characteristics, the operating status of at least the first negative pressure actuator and the second negative pressure actuator is dynamically adjusted; wherein, the first negative pressure actuator is configured to prioritize intercepting roof fracture gas, and the second negative pressure actuator is configured to prioritize pumping out goaf gas. By adjusting the first negative pressure actuator and the second negative pressure actuator differently, collaborative governance of gas from different sources can be achieved.

[0007] Preferably, the multi-source physical field parameters include at least: parameters characterizing the gas concentration field, parameters characterizing the environmental risk index field, parameters characterizing the airflow state field, and parameters characterizing the operating state field of multiple extraction and drainage execution terminals.

[0008] Preferably, the determination of the source characteristics of gas accumulation in the upper corner specifically includes: Constructing the contribution coefficient of the fracture source in the roof Contribution coefficient of air leakage sources in goaf and local wind entrapment coefficient ,in: In the formula, , These are the mixed flow rate and gas concentration of the high-level borehole or directional long borehole branch in the first negative pressure actuator; , These are the mixed flow rate and gas concentration of the buried or inserted pipe branch in the second negative pressure actuator, respectively; , These are the mixed flow rate and gas concentration of the upper corner guide branch, respectively; The concentration of gas in the upper corner; The concentration of gas in the return airflow; This refers to the local wind speed in the upper corner. This is a preset constant; According to the above , , Based on the size relationship, at least one main source type is determined under the current working conditions; the main source types include roof fissure gas source, goaf leakage gas source, and local air stagnation source.

[0009] Preferably, the determination of the source characteristics of gas accumulation in the upper corner further includes: Construct a comprehensive risk index The calculation formula is as follows: In the formula, The pressure difference between the goaf and the roadway; The oxygen concentration at the upper corner; This is the safe baseline value for oxygen concentration; The concentration of carbon monoxide in the upper corner; , , , , , These are weighting coefficients determined based on historical mine data; when , , When multiple coefficients in the system simultaneously exceed the preset contribution threshold, or when the increment of the comprehensive risk index R exceeds the preset risk mutation rate, the current condition is determined to be a composite dominant condition.

[0010] Preferably, the dynamic adjustment includes at least the operating states of the first negative pressure actuator and the second negative pressure actuator, specifically including: When it is determined that the gas source is dominated by the roof fissure, increase the negative pressure value and the number of branches opened at the first negative pressure actuator, and reduce the number of guide branches opened at the second negative pressure actuator that are directly connected to the goaf. When it is determined that the main source of air leakage and gas in the goaf is the gas source, the number of pipes and pipe branches in the second negative pressure actuator and the pumping capacity are increased, and the leakage blocking and diversion device is activated in conjunction. When it is determined that the source of local wind stagnation is dominant, adjust the position parameters of the upper corner airflow organization device and simultaneously adjust the extraction negative pressure intensity. When the condition is determined to be dominated by a combination of factors, the adjustment measures corresponding to the dominant gas source in the roof fissure and the dominant gas source in the goaf are activated simultaneously, and the oxygen concentration and carbon monoxide concentration are checked simultaneously.

[0011] Preferably, the first negative pressure actuator is connected to a high-level borehole or a directional long borehole located in the fracture development zone of the roof; the second negative pressure actuator is composed of a buried pipe, a telescopic pipe and an upper corner guide pipe arranged in parallel along the goaf.

[0012] Preferably, the main circuit of the second negative pressure actuator integrates multiple modular interface units with pitch switching function; the modular interface unit has at least a normal interface pitch and a peak interface pitch, wherein the normal interface pitch is greater than the peak interface pitch; The dynamic adjustment also includes an interface pitch switching strategy: during the stable period of gas outburst, the normal interface pitch is adopted; in the mining stress disturbance zone, geological structure zone, or when the comprehensive risk index R exceeds the preset working condition conversion threshold, the interface unit of the relevant section is switched to the peak interface pitch to increase the density of drainage points.

[0013] Preferably, it also includes an adaptive triggering mechanism that advances with mining: When the working face advances into the preset influence radius of any of the buried pipe interfaces or the modular interface units, the interface is automatically triggered to switch from standby state to priority opening state. When the working face pushes past the interface and the gas concentration and flow rate of the interface are monitored to continuously decrease to below the effective extraction threshold, the interface is automatically triggered to switch from the priority open state to the standby or closed state, and the next set of interfaces within the influence radius is activated at the same time, forming a continuous extraction architecture that changes with the mining space.

[0014] Preferably, the high-level borehole or directional long borehole branch in the first negative pressure actuator is subject to adaptive opening and closing control based on the decay rate and concentration change trend of the extracted gas purity of the branch.

[0015] Preferably, the multi-source physical field parameters include gas concentration indicators, low oxygen risk indicators, and spontaneous combustion correlation indicators; when dynamically adjusting the operating status of the first negative pressure actuator and the second negative pressure actuator, the control target of the gas concentration indicator, the constraint boundary of the low oxygen risk indicator and the spontaneous combustion correlation indicator are integrated into the same collaborative control logic model to form a multi-target linkage prevention and control mechanism for gas over-limit, low oxygen accumulation and residual coal oxidation.

[0016] Compared with the prior art, this application has the following beneficial effects: This invention proposes a method for the coordinated control of gas in the upper corner of a longwall face. By acquiring multi-source physical field parameters related to gas accumulation and associated risk evolution in the upper corner, the source characteristics of gas accumulation in the upper corner are determined. Based on this, the operating states of the first and second negative pressure actuators are dynamically adjusted to coordinate the control of gas from different sources in a differentiated manner. This effectively solves the technical problem of existing technologies that cannot identify the main source of gas in the upper corner and adaptively adjust the control loop accordingly, leading to mismatch between control measures and gas source conditions, decreased extraction efficiency, and difficulty in eradicating the risk of local gas exceedances. This method also addresses the issue of roof fractures. The gas interception function and the goaf gas drainage function are respectively configured on two independent and adjustable negative pressure execution ends, which enables the treatment system to automatically match the optimal negative pressure distribution, branch combination and drainage intensity according to the real-time identified source characteristics. This significantly improves the matching degree between treatment measures and dynamically changing gas source conditions, enhances the system's adaptability to complex working conditions, reduces the risk of measure mismatch and local gas accumulation under fixed parameter treatment conditions, and incorporates gas control targets and environmental risk indicators into the same control logic, realizing the coordinated prevention and control of gas over-limit, low oxygen accumulation and residual coal oxidation risks in the upper corner. Attached Figure Description

[0017] Figure 1 This is a technical flowchart of a method for coordinated control of gas in the upper corner of a longwall mining face, provided as an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the layout of the monitoring point at the upper corner and the guide point in the goaf in an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of the dual negative pressure collaborative adaptive gas control system in an embodiment of the present invention. Detailed Implementation

[0020] 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 embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Furthermore, in this invention, an element referred to as fixed to or disposed on another element may be directly disposed on the other element, or there may be an intermediate element. When an element is considered to be connected to another element, it may be directly connected to the other element, or there may be an intermediate element present simultaneously. The terms vertical, horizontal, left, right, and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0022] See Figures 1-3 This application provides a method for the coordinated control of gas in the upper corner of a longwall mining face, comprising: Acquire monitoring data of the upper corner and associated areas, wherein the monitoring data are multi-source physical field parameters related to gas accumulation and associated risk evolution in the upper corner; Based on the multi-source physical field parameters, the source characteristics of gas accumulation in the upper corner are determined; Based on the determined source characteristics, the operating status of at least the first negative pressure actuator and the second negative pressure actuator is dynamically adjusted; wherein, the first negative pressure actuator is configured to prioritize intercepting roof fracture gas, and the second negative pressure actuator is configured to prioritize pumping out goaf gas. By adjusting the first negative pressure actuator and the second negative pressure actuator differently, collaborative governance of gas from different sources can be achieved.

[0023] Specifically, the present invention provides a method for the coordinated control of gas in the upper corner of a longwall face. The core technical concept is to accurately identify the source characteristics of gas accumulation by acquiring multi-source physical field parameters of the upper corner and related areas in real time, and dynamically adjust the operating status of two complementary negative pressure actuators accordingly, so as to achieve coordinated control of gas from different sources in a differentiated manner.

[0024] First, during the advance of the longwall face, the source of gas accumulation in the upper corner is not singular and fixed, but dynamically changes with roof pressure, the evolution of air leakage channels in the goaf, and changes in local airflow conditions. If fixed extraction parameters and control measures are used, it will inevitably lead to a mismatch between the control measures and the actual gas source conditions. To solve this problem, this method establishes a joint acquisition mechanism for multi-source physical field parameters. Monitoring points are set up at different heights of the upper corner breathing zone, the turning point of the return airway, the near-field area of ​​the goaf behind the support, and the interface of each extraction guide branch to acquire various data related to gas accumulation and the evolution of associated risks in real time.

[0025] Secondly, based on the acquired multi-source physical field parameters, the source identification logic is executed to determine whether the gas accumulation in the upper corner under the current working conditions mainly comes from roof crack channels, air leakage in the goaf, local air stagnation in the upper corner, or a combination of multiple sources; this identification process is the core basis for subsequent control decisions.

[0026] Based on this, this method constructs a first negative pressure execution end and a second negative pressure execution end. The function of the first negative pressure execution end is to prioritize the interception of roof fracture gas. It is connected to a high-level borehole or directional long borehole located in the roof fracture development zone at the final borehole level, and intercepts and removes the gas before it flows into the working face through the fracture channel. The function of the second negative pressure execution end is to prioritize the drainage of goaf gas. It is composed of buried pipes, telescopic pipes and upper corner guide pipes connected in parallel in the goaf, forming a three-dimensional drainage network for near-field to deep gas in the goaf.

[0027] Finally, based on the identification results of the source characteristics, the negative pressure values ​​of the first negative pressure actuator and the second negative pressure actuator, the branch opening and closing combination and the extraction intensity are dynamically adjusted so that gas from different sources can be treated in a targeted and efficient manner under their respective main control conditions, achieving a synergistic treatment effect of targeted treatment.

[0028] In one specific embodiment, the multi-source physical field parameters include at least: parameters characterizing the gas concentration field, parameters characterizing the environmental risk index field, parameters characterizing the airflow state field, and parameters characterizing the operating state field of multiple extraction and drainage execution terminals.

[0029] The multi-source physical field parameters are specifically divided into four categories, each representing a different physical field state.

[0030] The first category consists of parameters characterizing the gas concentration field. The gas concentration field reflects the distribution characteristics and accumulation degree of gas in different spatial locations and is the core basis for judging the gas risk in the upper corner. In actual layout, stratified monitoring points are set at three heights of 0.5m, 1.6m, and 2.4m in the upper corner breathing zone to obtain the concentration gradient of gas in the vertical space of the upper corner. Monitoring points are set at the turning point of the return airway to obtain the average gas concentration of the return airflow.

[0031] The second category consists of parameters characterizing the environmental risk index field. The environmental risk index field is used to assess the low oxygen risk and residual coal oxidation risk associated with gas accumulation. It mainly obtains the oxygen concentration and carbon monoxide concentration in the upper corner. Oxygen concentration is a key indicator for judging the degree of air leakage and low oxygen accumulation in the goaf, while carbon monoxide concentration is an important indicator gas for identifying the spontaneous combustion and oxidation of residual coal.

[0032] The third category consists of parameters characterizing the airflow state field. The airflow state field determines the migration and retention conditions of gas in the upper corner. It mainly obtains the local wind speed in the upper corner and the pressure difference between the goaf and the roadway. The local wind speed reflects the ability of the airflow in the upper corner to sweep and dilute gas. The pressure difference between the goaf and the roadway characterizes the magnitude of the leakage driving force. The greater the pressure difference, the stronger the leakage from the goaf towards the working face.

[0033] The fourth category consists of parameters that characterize the operating status field of multiple extraction and drainage execution ends. These parameters reflect the actual response degree and extraction efficiency of each extraction and drainage branch to gas. They mainly obtain the extraction flow rate and gas concentration of the high-level borehole or directional long borehole branch in the first negative pressure execution end, as well as the extraction flow rate and gas concentration of the buried pipe branch, the inserted pipe branch, and the upper corner drainage branch in the second negative pressure execution end.

[0034] The above four types of parameters together constitute a complete system of multi-source physical field parameters, providing a data foundation for subsequent source identification and dynamic control.

[0035] In one specific implementation, determining the source characteristics of gas accumulation in the upper corner specifically includes: Constructing the contribution coefficient of the fracture source in the roof Contribution coefficient of air leakage sources in goaf and local wind entrapment coefficient ,in: In the formula, , These are the mixed flow rate and gas concentration of the high-level borehole or directional long borehole branch in the first negative pressure actuator; , These are the mixed flow rate and gas concentration of the buried or inserted pipe branch in the second negative pressure actuator, respectively; , These are the mixed flow rate and gas concentration of the upper corner guide branch, respectively; The concentration of gas in the upper corner; The concentration of gas in the return airflow; This refers to the local wind speed in the upper corner. This is a preset constant; According to the above , , Based on the size relationship, at least one main source type is determined under the current working conditions; the main source types include roof fissure gas source, goaf leakage gas source, and local air stagnation source.

[0036] That is, by constructing three contribution coefficients, the main source of gas in the upper corner can be quantitatively identified.

[0037] The three contribution coefficients are the contribution coefficients of the roof fracture source. Contribution coefficient of air leakage sources in goaf and local wind entrapment coefficient .

[0038] The calculation formula is: The physical meaning of this formula lies in calculating the ratio of the pure gas volume (product of flow rate and concentration) extracted by the high-level borehole or directional long borehole branch in the first negative pressure actuator to the sum of the pure gas volumes extracted by all extraction and drainage branches; when A larger value indicates that the gas gushing from the roof fissure channels accounts for a high proportion of the total drainage volume, and that the roof fissure gas plays a dominant role in the gas accumulation in the upper corner.

[0039] The calculation formula is: This formula calculates the ratio of the pure gas volume extracted by the buried or inserted pipe branch in the second negative pressure actuator to the sum of the pure gas volumes extracted by all branches; when A larger value indicates that the gas carried by the goaf leakage accounts for a high proportion of the total drainage volume, and the goaf leakage plays a dominant role in the gas accumulation in the upper corner.

[0040] The calculation formula is: This formula characterizes the degree of gas retention in the local space of the upper corner by calculating the difference between the gas concentration in the upper corner and the gas concentration in the return air, and correcting for it with the local wind speed in the upper corner. When the concentration in the upper corner is significantly higher than that in the return air, and the local wind speed is low, An increase in the value indicates a significant wind trapping effect at the upper corner; ε is a preset constant in the formula, which is used to prevent the denominator from being zero and causing calculation abnormalities, and is usually taken as 0.1.

[0041] In actual operation, the above three coefficients are calculated in real time, and their magnitudes are compared; when Significantly greater than and At that time, it was determined that the current working condition was dominated by gas sources from roof cracks; when Significantly greater than and At that time, it was determined that the current working condition was dominated by gas leakage from the goaf; when Significantly greater than and When the current operating condition is determined to be dominated by localized wind stagnation sources, this quantitative identification method provides a clear mathematical basis for determining the source characteristics, avoiding the subjectivity of experience-based judgment.

[0042] In one specific embodiment, determining the source characteristics of gas accumulation in the upper corner further includes: Construct a comprehensive risk index The calculation formula is as follows: In the formula, The pressure difference between the goaf and the roadway; The oxygen concentration at the upper corner; This is the safe baseline value for oxygen concentration; The concentration of carbon monoxide in the upper corner; , , , , , These are weighting coefficients determined based on historical mine data; when , , When multiple coefficients in the system simultaneously exceed the preset contribution threshold, or when the increment of the comprehensive risk index R exceeds the preset risk mutation rate, the current condition is determined to be a composite dominant condition.

[0043] Overall Risk Index The calculation formula is: .

[0044] The formula integrates six risk assessment dimensions; the first item The second item reflects the direct contribution of gas concentration in the upper corner to risk; The third item reflects the weight of the contribution of air leakage sources in the goaf to the risk. This reflects the degree to which localized wind stagnation exacerbates the risk; Item 4 The fifth item reflects the intensity of the air leakage driving force, characterized by the pressure difference between the goaf and the roadway. This reflects the degree to which the oxygen concentration in the upper corner deviates from the normal atmospheric oxygen content baseline. The lower the oxygen concentration in the upper corner, the larger this difference, and the higher the risk of hypoxia; Item 6 The risk of coal oxidation is reflected in the carbon monoxide concentration in the upper corner.

[0045] Weighting coefficients in the formula , , , , , Based on historical monitoring data of the mine, the values ​​of various parameters before multiple gas exceedance events or risk events in the upper corner of the mine in history can be collected. The probability or severity of the risk event is used as the dependent variable, and the above six parameters are used as independent variables. The optimal values ​​of each weight coefficient are determined by multiple linear regression or logistic regression. Due to differences in mining conditions, coal seam gas occurrence characteristics and ventilation systems, the specific values ​​of the weight coefficients may vary in different mines, but the determination method is universal.

[0046] After completion , , and After calculation, a comprehensive judgment is made on the current working condition type; when , , When only one coefficient is significantly higher than the other two, it is determined to be a single-source dominant condition; when multiple coefficients simultaneously exceed their respective preset contribution thresholds, for example... and At the same time, a high level indicates that both roof fissure gas and goaf leakage gas are significantly affecting gas accumulation in the upper corner; or, when the increase in the comprehensive risk index R exceeds the preset risk mutation rate in a short period of time, it indicates that the risk is rising rapidly; in both cases, it is determined that the current situation is dominated by a complex combination of factors, and the most comprehensive countermeasures need to be initiated.

[0047] In one specific embodiment, the dynamic adjustment includes at least the operating states of the first negative pressure actuator and the second negative pressure actuator, specifically including: When it is determined that the gas source is dominated by the roof fissure, increase the negative pressure value and the number of branches opened at the first negative pressure actuator, and reduce the number of guide branches opened at the second negative pressure actuator that are directly connected to the goaf. When it is determined that the main source of air leakage and gas in the goaf is the gas source, the number of pipes and pipe branches in the second negative pressure actuator and the pumping capacity are increased, and the leakage blocking and diversion device is activated in conjunction. When it is determined that the source of local wind stagnation is dominant, adjust the position parameters of the upper corner airflow organization device and simultaneously adjust the extraction negative pressure intensity. When the condition is determined to be dominated by a combination of factors, the adjustment measures corresponding to the dominant gas source in the roof fissure and the dominant gas source in the goaf are activated simultaneously, and the oxygen concentration and carbon monoxide concentration are checked simultaneously.

[0048] When the primary source of gas is determined to be fractured gas in the roof, the first control strategy is implemented. The core of this strategy is to concentrate negative pressure resources to intercept fractured gas. Specifically, the negative pressure value at the first negative pressure execution end is increased to enhance the suction capacity of the extraction pipeline to the borehole. At the same time, the number of high-level boreholes or directional long borehole branches opened at the first negative pressure execution end is increased to expand the interception coverage of fractured gas. In conjunction with this, the number of drainage branches directly connected to the goaf at the second negative pressure execution end is reduced to avoid the effective negative pressure of the fractured extraction branches being reduced due to multi-point diversion of the negative pressure system.

[0049] When the goaf is determined to be the dominant source of gas leakage, the second control strategy is implemented. The core of this strategy is to enhance the gas drainage capacity of the deep goaf while weakening the gas-carrying effect of leakage. Specifically, the number and drainage capacity of the buried pipe branches and inserted pipe branches in the second negative pressure actuator are increased so that the gas in the goaf is drawn away by the drainage pipelines before entering the working face. At the same time, the leakage blocking and diversion device set in the transition area between the goaf and the working face is activated. The specific form of the leakage blocking and diversion device may include: a flexible leakage plugging component set behind the support on the goaf side to reduce the cross-section of the leakage channel from the goaf to the working face; a wind barrier set at the junction of the working face and the return airway to guide the direction of leakage; and a wind guide device to change the local airflow direction.

[0050] When the source of gas stagnation is determined to be localized, the third control strategy is implemented. The core of this strategy is to improve the airflow organization in the upper corner and eliminate gas stagnation conditions. Specifically, the positional parameters of the airflow organization device set in the upper corner are adjusted, such as changing the installation position and height of the windbreak, adjusting the pointing angle of the air guide, or changing the working state and jet direction of the ejector, so as to enhance the sweeping and replacement capacity of fresh airflow on the breathing zone of the upper corner. At the same time, it is necessary to appropriately control the extraction negative pressure intensity to avoid the formation of a new negative pressure vortex zone in the upper corner due to excessive extraction, which would induce further air leakage in the goaf.

[0051] When the condition is determined to be a combined dominant operating condition, the fourth control strategy is implemented. This strategy is a comprehensive application of the aforementioned strategies, simultaneously activating the gas interception measures in the first control strategy and the gas drainage measures in the second control strategy. More importantly, under this condition, the oxygen concentration and carbon monoxide concentration need to be checked simultaneously. This is because significantly increasing drainage may lead to increased air leakage in the goaf, resulting in the dual risks of reduced oxygen concentration in the upper corner and improved oxygen supply conditions from residual coal. The purpose of the simultaneous check is to ensure that while the gas concentration is under control, the oxygen concentration is not lower than the safety lower limit and the carbon monoxide concentration does not exceed the warning threshold.

[0052] In one specific embodiment, the first negative pressure actuator is connected to a high-level borehole or a directional long borehole located in the fracture development zone of the roof; the second negative pressure actuator is composed of a buried pipe, a telescopic pipe and an upper corner guide pipe arranged in parallel along the goaf.

[0053] The core extraction interface of the first negative pressure actuator is a high-level borehole or a long directional borehole. In terms of construction layout, the final borehole position needs to be located within the roof fracture development zone. The roof fracture development zone is a region rich in fracture networks formed in the overlying rock after mining-induced pressure relief, and it is also the main channel for the upward movement of coal seam depressurized gas. By arranging the final borehole position here, an interception point can be formed on the path of gas movement along the fracture channel towards the working face, realizing the pre-extraction of gas. As the working face continues to advance and the roof in front gradually enters the fracture development zone, the borehole can continuously intercept the newly released depressurized gas. In engineering practice, depending on the drilling equipment conditions of the mine, a long directional borehole constructed by a kilometer-long directional drilling rig or a high-level borehole constructed by a conventional rotary drilling rig can be selected, both of which can achieve the above-mentioned interception function.

[0054] The second negative pressure actuator consists of three types of parallel guide units. The first type is a goaf-buried pipe, which is a pipe pre-buried or jacked into the goaf before or during the working face mining process, with the pipe interface located in the high gas accumulation area of ​​the goaf. The second type is a telescopic pipe, which can extend into the goaf to a certain depth from the gap behind the support, and its insertion depth can be flexibly adjusted according to the gas distribution in the goaf. The third type is an upper corner guide pipe, which is arranged near the upper corner breathing zone to directly extract the locally accumulated gas in the upper corner. The three types of guide units are connected in parallel to the main pipeline, forming a three-level three-dimensional guide network covering the deep goaf, the near field of the goaf, and the local space of the upper corner, ensuring that goaf gas from different locations can be effectively extracted.

[0055] In one specific embodiment, the main circuit of the second negative pressure actuator integrates multiple modular interface units with pitch switching function; the modular interface unit has at least a normal interface pitch and a peak interface pitch, wherein the normal interface pitch is greater than the peak interface pitch.

[0056] The dynamic adjustment also includes an interface pitch switching strategy: during the stable period of gas outburst, the normal interface pitch is adopted; in the mining stress disturbance zone, geological structure zone, or when the comprehensive risk index R exceeds the preset working condition conversion threshold, the interface unit of the relevant section is switched to the peak interface pitch to increase the density of drainage points.

[0057] Along the main guide pipe of the second negative pressure actuator, multiple modular interface units are integrated at certain intervals; each interface unit has two switchable interface pitches, with the normal interface pitch having a larger spacing, for example, an 8m interval arrangement; and the peak interface pitch having a smaller spacing, for example, a 5m interval arrangement.

[0058] During the relatively stable normal phase of gas outburst, normal interface pitch operation is adopted; the larger interface spacing reduces the number of interfaces on the main pipeline and the local resistance loss, which is conducive to the stable operation and energy saving of the pipeline system, while meeting the gas drainage needs of the goaf under normal mining conditions.

[0059] When the working face enters the mining-induced stress disturbance zone (such as the area affected by periodic pressure), the geological structure zone (such as the fault and fold influence zone), or the abnormal gas outburst zone, the gas outburst in the goaf may increase significantly in the short term, and the original interface spacing may not be able to effectively cover the local high-concentration gas enrichment area. At this time, the system automatically judges the working condition transition conditions based on the change of the comprehensive risk index R. When R exceeds the preset working condition transition threshold, the interface unit in the relevant section is switched from the normal interface pitch to the peak interface pitch. The smaller interface spacing can increase the density of drainage points without increasing the main pipeline, making the gas drainage coverage more dense and enhancing the treatment intensity of the local high gas enrichment area.

[0060] The pitch switching of the modular interface unit can be achieved through hydraulic drive, electric push rod or manual quick coupling, and the specific form can be selected according to the equipment conditions and automation level of the mine.

[0061] In one specific implementation, an adaptive triggering mechanism is also included as mining progresses: When the working face advances into the preset influence radius of any of the buried pipe interfaces or the modular interface units, the interface is automatically triggered to switch from standby state to priority opening state. When the working face pushes past the interface and the gas concentration and flow rate of the interface are monitored to continuously decrease to below the effective extraction threshold, the interface is automatically triggered to switch from the priority open state to the standby or closed state, and the next set of interfaces within the influence radius is activated at the same time, forming a continuous extraction architecture that changes with the mining space.

[0062] As the longwall face continues to advance, the goaf area expands and the upper corner moves forward. Fixed pipe or interface layouts inevitably lead to some interfaces being further and further away from the upper corner, resulting in a gradual decrease in drainage effectiveness. To address this issue, this method introduces an adaptive triggering mechanism based on the working face advance distance.

[0063] The specific implementation method is as follows: In the control system or on-site management procedures, the priority action area, i.e. the radius of influence, is preset for each buried pipe interface and modular interface unit. The radius of influence can be determined according to the gas migration law of the goaf and the effective range of pipeline drainage. For example, it can be set as a 10m interval before and after the interface. When the working face enters the radius of influence of a certain interface as it advances, the interface is in the optimal drainage position. At this time, the control system automatically or with the assistance of manual instructions switches the interface from the standby state to the priority opening state, so that it can be put into operation with the maximum drainage capacity.

[0064] As the working face continues to advance and passes the interface, the distance between the interface and the upper corner gradually increases, and the drainage target gradually changes from the high-gas area of ​​the goaf to the deep compacted area of ​​the goaf. With this change in spatial position, the drainage gas concentration and flow rate of the interface will gradually decrease. When the monitoring data shows that the drainage concentration and flow rate of the interface are continuously lower than the preset effective drainage threshold, the system automatically switches the interface from the priority open state to the standby or closed state, and at the same time activates the next set of interfaces in the direction of working face advancement that have entered its influence radius.

[0065] Through this triggering mechanism of opening before closing and continuous operation, the guide and drainage interface in the goaf always maintains the optimal spatial matching relationship with the upper corner position of the working face, forming a continuous drainage structure that evolves with the mining space, ensuring that the key area in the upper corner is always in an effective treatment state throughout the entire mining period.

[0066] In one specific implementation, the high-level borehole or directional long borehole branch in the first negative pressure actuator is adaptively controlled to open and close based on the decay rate and concentration change trend of the extracted gas purity of the branch.

[0067] The extraction capacity of high-level boreholes or directional long borehole branches in the first negative pressure actuator is not constant. As the working face advances, the spatial relationship between the drilled boreholes and the working face changes continuously. When the working face is close to the end of the borehole, the borehole is located in a high-permeability area with developed fractures, and the purity and concentration of extracted gas are at a high level. When the working face has passed the end of the borehole by a considerable distance, the goaf where the borehole is located is gradually compacted, the fractures close, the permeability drops significantly, and the purity and concentration of extracted gas from the borehole also decreases accordingly.

[0068] To achieve dynamic matching between the drilling service cycle and the spatiotemporal relationship of the working face advancement, adaptive control is implemented for the operating status of each borehole branch. When the rate of decrease in the pure gas extraction volume of a certain borehole branch is continuously increasing and the concentration shows a downward trend, it indicates that the borehole has entered the final stage of extraction. When the pure gas extraction volume is lower than the economic extraction threshold or the concentration is lower than the effective utilization threshold, the borehole branch is switched from the open state to the closed or standby state. At the same time, newly constructed boreholes ahead of the working face can be put into operation simultaneously. Through this dynamic opening and closing control, the first negative pressure actuator always maintains an efficient interception capacity for roof fracture gas, avoiding energy waste caused by ineffective extraction and the negative pressure diversion effect on other effective branches.

[0069] In one specific implementation, the multi-source physical field parameters include a gas concentration index, a low-oxygen risk index, and a spontaneous combustion correlation index. When dynamically adjusting the operating states of the first negative pressure actuator and the second negative pressure actuator, the control target of the gas concentration index, the constraint boundaries of the low-oxygen risk index and the spontaneous combustion correlation index are integrated into the same collaborative control logic model to form a multi-target linkage prevention and control mechanism for gas over-limit, low-oxygen accumulation and residual coal oxidation.

[0070] In traditional upper corner gas management, gas concentration control is often the only regulatory target. However, in actual engineering, enhanced gas extraction may bring two associated risks: First, excessive negative pressure during extraction may induce increased air leakage in the goaf, leading to a decrease in oxygen concentration in the upper corner and the formation of a low-oxygen risk zone, threatening the safety of workers. Second, increased air leakage provides more oxygen to the residual coal in the goaf, which may accelerate the oxidation and spontaneous combustion process of the residual coal.

[0071] This method integrates the control target of gas concentration, the constraint boundary of low oxygen risk, and the constraint boundary of spontaneous combustion-related indicators into the same collaborative control logic model when dynamically adjusting the operating status of the first and second negative pressure actuators. This logic model takes keeping gas concentration within limits as the primary control target, oxygen concentration not lower than the safety lower limit as a hard constraint, and carbon monoxide concentration not exceeding the warning value as the monitoring boundary. When the control measures cause the oxygen concentration to approach the constraint lower limit or the carbon monoxide concentration to rise significantly, the system automatically corrects the control parameters in reverse. Under the premise of ensuring that the gas concentration is controlled, the environmental risk indicators are maintained within the safe range, thereby achieving collaborative prevention and control of three types of risks: gas exceeding limits, low oxygen accumulation, and residual coal oxidation in the upper corner.

[0072] Example 1 This example focuses on a fully mechanized mining face in a high-gas mine. The face exhibits typical characteristics of multi-source gas accumulation, including significant air leakage in the goaf, well-developed roof fissures, and easy formation of localized air pockets in the upper corner.

[0073] Reference Figure 1 The technical process shown first involves constructing a multi-parameter monitoring system; such as... Figure 2 As shown, three monitoring points M1, M2, and M3 are set up in the upper corner of the working face, located at three vertical stratification heights of 0.5m, 1.6m, and 2.4m in the upper corner breathing zone, respectively, to obtain the concentration gradient distribution of gas in the vertical space of the upper corner. Three monitoring points M4, M5, and M6 are set up outside the turning point of the return airway to obtain the average gas concentration and airflow status of the return airflow. Behind the support along the goaf direction, near-field gradient monitoring points G1, G2, and G3 are set up at distances of 5m, 15m, and 25m from the working face to identify the gas migration and return patterns in the goaf. The roof fracture drainage support... Monitoring points D1 and D2 are set at the road interface to obtain the extraction flow rate and concentration of the high-level borehole branch; monitoring points P1 and P2 are set at the interface of the buried pipe branch in the goaf to obtain the extraction flow rate and concentration of the buried pipe branch; the above monitoring points together form a joint monitoring system for the local space in the upper corner, the near-field space of the goaf, and the operating status of each extraction and drainage branch; the monitoring parameters obtained include the volume fraction of methane, oxygen, and carbon monoxide in the upper corner, local wind speed, pressure difference between the goaf and the roadway, flow rate and concentration of the high-level borehole branch, flow rate and concentration of the buried pipe branch in the goaf, and flow rate and concentration of the drainage branch.

[0074] Based on the obtained multi-source physical field parameters, the main source of gas in the upper corner is identified; specifically, the contribution coefficient of the roof crack source is constructed. Contribution coefficient of air leakage sources in goaf and local wind entrapment coefficient The calculation formulas are as follows: In the formula, , These represent the mixed flow rate and gas concentration of the high-level borehole branch, respectively. , These represent the mixed flow rate and gas concentration of the buried or inserted pipe branches, respectively. , These represent the mixed flow rate and gas concentration of the upper corner guide branch, respectively. The concentration of gas in the upper corner. The concentration of gas in the return airflow. This refers to the local wind speed in the upper corner. The constant is set as a preset value; to further identify complex working conditions caused by multiple sources working together, a comprehensive risk index R is constructed, and the calculation formula is as follows: In the formula The pressure difference between the goaf and the roadway. The oxygen concentration at the upper corner. This is the safe baseline value for oxygen concentration. The carbon monoxide concentration in the upper corner. , , , , , These are weighting coefficients determined based on historical mine data.

[0075] Based on the calculation results of the above identification indicators, the current working condition type is determined; when Significantly greater than and At that time, it was determined that the operating condition was dominated by gas sources from roof cracks; when Significantly greater than and At that time, it was determined to be the dominant working condition of air leakage and gas source in the goaf; when Significantly greater than and When the local wind stagnation source is the dominant operating condition, it is determined to be a local wind stagnation source; when multiple coefficients exceed the preset contribution threshold at the same time, or when the increment of the comprehensive risk index R exceeds the preset risk mutation rate, it is determined to be a composite dominant operating condition.

[0076] Reference Figure 3 As shown, a dual negative pressure coordinated management system is constructed, consisting of a high negative pressure fracture extraction circuit and a low negative pressure goaf drainage circuit. The high negative pressure fracture extraction circuit is connected to a high-level borehole, with the final borehole layer located within the roof fracture development area, to preferentially intercept depressurized gas that continuously migrates along the roof fracture channel. The low negative pressure goaf drainage circuit is composed of buried pipes, telescopic pipes, and upper corner drainage pipes arranged in parallel along the goaf, forming a three-level three-dimensional drainage network covering the deep goaf, the near field of the goaf, and the local space of the upper corner.

[0077] During operation, differentiated control strategies are implemented based on the identification results of the working condition type. When the gas source is determined to be dominated by roof fractures, the negative pressure value and the number of branches opened in the high negative pressure fracture extraction circuit are increased to enhance the interception capacity of gas in the roof fracture channels. At the same time, the number of drainage branches directly connected to the goaf in the low negative pressure goaf drainage circuit is reduced to avoid system diversion. When the gas source is determined to be dominated by goaf leakage, the number of buried pipes and inserted pipe branches opened and the drainage capacity in the low negative pressure goaf drainage circuit are increased, and the leakage prevention system set in the transition area between the goaf and the working face is activated in conjunction with these measures. The diversion device weakens the gas-carrying effect of air leakage; when the local stagnant air source is determined to be dominant, the focus is on adjusting the local airflow organization in the upper corner, changing the position and height of the wind barrier, adjusting the angle of the air duct and the working state of the ejector, improving the airflow sweeping ability of the upper corner breathing zone, and controlling the intensity of the extraction negative pressure to prevent further enhancement of extraction-induced air leakage; when the combined dominant working condition is determined to be dominant, the fissure gas interception and goaf gas drainage measures are initiated simultaneously, and the oxygen concentration and carbon monoxide concentration are checked simultaneously to ensure that the gas concentration is controlled while suppressing the risk of low oxygen accumulation and residual coal oxidation.

[0078] The main pipe of the drainage circuit along the low negative pressure goaf integrates multiple modular T-type tee interface units with pitch switching function; under normal working conditions, a larger pitch of 8m is used to reduce pipeline resistance and maintain system stability; when the working face enters the structural disturbance zone, mine pressure manifestation zone, gas abnormal zone, or the comprehensive risk index R continues to rise, the interfaces in the relevant sections are switched to a smaller pitch of 5m to enhance the drainage capacity of the local high gas enrichment zone by increasing the density of drainage points.

[0079] Meanwhile, the system is equipped with a distance triggering mechanism that advances with mining. When the working face advances to a predetermined distance range near a certain group of buried pipe interfaces or T-shaped tee interfaces, the interface is automatically switched to the priority opening state. When the working face passes the interface and the extraction concentration and flow rate are monitored to continuously decrease to below the effective extraction threshold, the interface is switched to the standby state and the next group of interfaces is started. For high-level borehole branches, the opening and closing are adjusted according to the decay rate of the extraction volume and the concentration change trend, so as to achieve dynamic matching between the fracture gas extraction service cycle and the spatiotemporal relationship of the working face advancement.

[0080] Through the implementation of the above technical solutions, the gas concentration in the upper corner of the working face was always controlled within the safe threshold during the entire mining period, and no gas exceeding the limit event occurred. The oxygen concentration and carbon monoxide concentration were also kept within the safe range, achieving good control results.

[0081] Example 2 This case study focuses on a fully mechanized longwall face in a mine. This face has a thick coal seam, a lot of residual coal in the goaf, well-developed roof fissures, and complex and frequently changing gas sources in the upper corner, making conventional fixed-parameter control measures difficult to effectively address the issue.

[0082] In the deployment of the monitoring system, refer to Figure 2 As shown, monitoring points M1 to M3 are set in layers in the upper corner breathing zone, monitoring points M4 to M6 are set outside the turning point of the return airway, and gradient monitoring points G1 to G3 are set in the direction of the goaf behind the support. At the same time, corresponding flow and concentration monitoring units are set at the interface of the roof fracture extraction branch and the interface of the goaf buried pipe branch. All monitoring data are transmitted to the ground monitoring center in real time to provide a data basis for source identification.

[0083] During the mining process, monitoring data on a certain day showed that the gas concentration in the upper corner continued to rise, approaching the warning value; calculations showed that the contribution coefficient of the roof fracture source at this time was... The contribution coefficient of air leakage sources in the goaf is approximately 0.52. Approximately 0.25, local wind entrapment coefficient Approximately 0.18; The condition is clearly dominant, indicating that the current operating condition is dominated by roof fissure gas sources.

[0084] Based on the assessment results, the system automatically increased the negative pressure of the high negative pressure fracture drainage circuit from 35 kPa to 48 kPa, and opened two more sets of high-level borehole branches, increasing the total number of open branches from 4 to 6, in order to enhance the interception capacity of gas in the roof fracture channels. At the same time, the number of open branches of the goaf buried pipe in the low negative pressure goaf drainage circuit was reduced from 3 to 1, and only the upper corner drainage pipe branch was kept in operation to prevent negative pressure resources from being diverted to drainage branches that are not controlled by the main source. About 30 minutes after the adjustment, the gas concentration in the upper corner decreased from 0.78% to 0.42%, falling back to the safe range.

[0085] A week later, as the working face advanced into the area affected by periodic pressure, air leakage in the goaf significantly increased; monitoring data showed... It rose to 0.48. The comprehensive risk index R dropped to 0.28, significantly increasing; the system determined that the current working condition was dominated by gas leakage from the goaf; at this time, the buried pipe branch of the low negative pressure goaf drainage circuit was automatically increased from 1 group to 4 groups, and the inserted pipe branch was increased from 2 groups to 5 groups, comprehensively enhancing the drainage capacity of deep gas in the goaf; at the same time, flexible leak-sealing components were activated behind the support, reducing the cross-section of the air leakage channel from the goaf to the working face, and a wind barrier was added at the upper corner of the working face to guide the air leakage direction away from the upper corner breathing zone; through the above adjustments, the gas concentration at the upper corner was effectively controlled.

[0086] Several days later, monitoring data showed that the oxygen concentration decreased from 20.5% to 19.1%, while the carbon monoxide concentration increased from 5 ppm to 18 ppm. , Both were at a high level; the system determined that it had entered a combined dominant working condition; at this time, the measures of fissure gas interception and goaf gas drainage were initiated simultaneously, and the control parameters were checked for oxygen and carbon monoxide simultaneously; under the premise of keeping the gas concentration under control, the drainage negative pressure of the buried pipe branch was appropriately reduced to reduce the increase of air leakage in the goaf, and the drainage frequency of the upper corner guide pipe was increased; after adjustment, the oxygen concentration rose to above 20.2%, and the carbon monoxide concentration fell to below 10 ppm, realizing the coordinated prevention and control of gas exceeding the limit, low oxygen accumulation and residual coal oxidation.

[0087] Throughout the mining process, the pitch of the T-shaped three-way interface unit automatically switches according to the working conditions. In the normal advance section of the working face, an 8m normal pitch is used. When entering the structural disturbance zone or the periodic pressure influence zone, it switches to a 5m peak pitch. The distance triggering mechanism that advances with the mining also runs continuously. Whenever the working face advances a certain distance and crosses a set of interfaces, the next set of interfaces automatically takes over and is put into operation, ensuring that the key areas in the upper corner are always in an effective treatment state.

[0088] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0089] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for coordinated control of gas in the upper corner of a longwall face, characterized in that, include: Acquire monitoring data of the upper corner and associated areas, wherein the monitoring data are multi-source physical field parameters related to the gas accumulation and associated risk evolution in the upper corner; Based on the multi-source physical field parameters, the source characteristics of gas accumulation in the upper corner are determined; Based on the determined source characteristics, the operating status of at least the first negative pressure actuator and the second negative pressure actuator is dynamically adjusted; wherein, the first negative pressure actuator is configured to prioritize intercepting roof fracture gas, and the second negative pressure actuator is configured to prioritize pumping out goaf gas. By adjusting the first negative pressure actuator and the second negative pressure actuator differently, collaborative governance of gas from different sources can be achieved.

2. The method according to claim 1, characterized in that, The multi-source physical field parameters include at least: parameters characterizing the gas concentration field, parameters characterizing the environmental risk index field, parameters characterizing the airflow state field, and parameters characterizing the operating state field of multiple extraction and drainage execution terminals.

3. The method according to claim 2, characterized in that, The characteristics used to determine the source of gas accumulation in the upper corner specifically include: Constructing the contribution coefficient of the fracture source in the roof Contribution coefficient of air leakage sources in goaf and local wind entrapment coefficient ,in: In the formula, , These are the mixed flow rate and gas concentration of the high-level borehole or directional long borehole branch in the first negative pressure actuator; , These are the mixed flow rate and gas concentration of the buried or inserted pipe branch in the second negative pressure actuator, respectively; , These are the mixed flow rate and gas concentration of the upper corner guide branch, respectively; The concentration of gas in the upper corner; The concentration of gas in the return airflow; This refers to the local wind speed in the upper corner. This is a preset constant; According to the above , , Based on the size relationship, at least one main source type is determined under the current working conditions; the main source types include roof fissure gas source, goaf leakage gas source, and local air stagnation source.

4. The method according to claim 3, characterized in that, The determination of the source characteristics of gas accumulation in the upper corner also includes: Construct a comprehensive risk index The calculation formula is as follows: In the formula, This refers to the pressure difference between the goaf and the roadway. The oxygen concentration at the upper corner; This is the safe baseline value for oxygen concentration; The concentration of carbon monoxide in the upper corner; , , , , , These are weighting coefficients determined based on historical mine data; when , , When multiple coefficients in the system simultaneously exceed the preset contribution threshold, or when the increment of the comprehensive risk index R exceeds the preset risk mutation rate, the current condition is determined to be a composite dominant condition.

5. The method according to claim 4, characterized in that, The dynamic adjustment includes at least the operating states of the first negative pressure actuator and the second negative pressure actuator, specifically including: When it is determined that the gas source is dominated by the roof fissure, increase the negative pressure value and the number of branches opened at the first negative pressure actuator, and reduce the number of guide branches opened at the second negative pressure actuator that are directly connected to the goaf. When it is determined that the main source of air leakage and gas in the goaf is the gas source, the number of pipes and pipe branches in the second negative pressure actuator and the pumping capacity are increased, and the leakage blocking and diversion device is activated in conjunction. When it is determined that the source of local wind stagnation is dominant, adjust the position parameters of the upper corner airflow organization device and simultaneously adjust the extraction negative pressure intensity. When the condition is determined to be dominated by a combination of factors, the adjustment measures corresponding to the dominant gas source in the roof fissure and the dominant gas source in the goaf are activated simultaneously, and the oxygen concentration and carbon monoxide concentration are checked simultaneously.

6. The method according to claim 1 or 5, characterized in that, The first negative pressure actuator is connected to a high-level borehole or a directional long borehole located in the fracture development zone of the roof; the second negative pressure actuator is composed of a buried pipe, a telescopic pipe and an upper corner guide pipe arranged in parallel along the goaf.

7. The method according to claim 6, characterized in that, The main circuit of the second negative pressure actuator integrates multiple modular interface units with pitch switching function; the modular interface unit has at least a normal interface pitch and a peak interface pitch, wherein the normal interface pitch is greater than the peak interface pitch; The dynamic adjustment also includes an interface pitch switching strategy: during the stable period of gas outburst, the normal interface pitch is adopted; in the mining stress disturbance zone, geological structure zone, or when the comprehensive risk index R exceeds the preset working condition conversion threshold, the interface unit of the relevant section is switched to the peak interface pitch to increase the density of drainage points.

8. The method according to claim 7, characterized in that, It also includes an adaptive triggering mechanism that advances with mining: When the working face advances into the preset influence radius of any of the buried pipe interfaces or the modular interface units, the interface is automatically triggered to switch from standby state to priority opening state. When the working face pushes past the interface and the gas concentration and flow rate of the interface are monitored to continuously decrease to below the effective extraction threshold, the interface is automatically triggered to switch from the priority open state to the standby or closed state, and the next set of interfaces within the influence radius is activated at the same time, forming a continuous extraction architecture that changes with the mining space.

9. The method according to claim 6, characterized in that, The high-level borehole or directional long borehole branch in the first negative pressure actuator is subject to adaptive opening and closing control based on the decay rate and concentration change trend of the extracted gas in the branch.

10. The method according to claim 1, characterized in that, The multi-source physical field parameters include gas concentration indicators, low oxygen risk indicators, and spontaneous combustion correlation indicators. When dynamically adjusting the operating status of the first negative pressure actuator and the second negative pressure actuator, the control target of the gas concentration indicator, the constraint boundary of the low oxygen risk indicator and the spontaneous combustion correlation indicator are integrated into the same collaborative control logic model to form a multi-target linkage prevention and control mechanism for gas over-limit, low oxygen accumulation and residual coal oxidation.

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