A method for ventilation optimization for coal mine underground working environment

Abstract

The application discloses a kind of ventilation optimization methods for coal mine underground operating environment, it is related to coal mine operating safety technical field, and the coal mine underground operating space area is divided into several grid partition units, and sets up air pressure buffer zone at junction, according to the real-time advancing amount of coal mining face dynamically changes ventilation distribution mode, and by air pressure buffer zone auxiliary ventilation, constructs underground three-dimensional topological model monitoring area environmental parameter, according to its solution different grid partition unit ventilation standard rate, judge whether to execute the topological dynamic reconstruction of coal mine underground operating space area, constructs fan power adjustment model and carries out fan intelligent control, obtains the air volume and air velocity at different mining and tunneling depth, and calculates the air pressure loss value at corresponding mining and tunneling depth, several stages of booster station are arranged between underground ventilation equipment and mining working face, according to air pressure loss value obtains air volume compensation value, carries out air volume supply at each mining and tunneling depth, to realize efficient ventilation optimization.

Description

Technical Field

[0001] This invention relates to the field of coal mine operation safety technology, specifically a ventilation optimization method for underground coal mine working environments. Background Technology

[0002] Coal mine ventilation refers to the use of certain technical means and equipment to deliver fresh air into the coal mine and expel polluted air, in order to meet the breathing needs of underground workers, dilute and expel harmful gases and dust, and regulate the underground climate. It is an important guarantee for safe production in coal mines, and it is directly related to the life safety of underground personnel and the normal production order of the mine.

[0003] Existing coal mine ventilation methods have the following drawbacks:

[0004] 1. The fixed air volume ventilation distribution mode cannot adapt to the dynamic changes of the coal mine face, resulting in gas accumulation in some areas of the underground working space, which affects the overall ventilation efficiency of the underground environment.

[0005] 2. When underground ventilation equipment is used in coal mining, as the mining depth increases, the phenomenon of uneven air supply during coal mining operations will occur.

[0006] Therefore, how to handle the contradiction between static air volume distribution and dynamic mining, how to adaptively adjust the air volume supply according to the increase in mining depth, and how to solve the problem of equipment energy waste in order to achieve efficient ventilation optimization for the underground working environment of coal mines are currently key and difficult issues in the field of coal mine operation safety technology. Summary of the Invention

[0007] To address the aforementioned problems, the present invention aims to provide a ventilation optimization method for underground coal mine working environments.

[0008] The objective of this invention can be achieved through the following technical solution: a ventilation optimization method for underground coal mine working environments, comprising the following steps:

[0009] Step S1: Divide the underground working space of the coal mine into several grid partition units, and set up air pressure buffer zones at the junctions of the grid partition units;

[0010] Step S2: Dynamically change the ventilation distribution mode of the grid partition unit according to the real-time advance of the coal mine face, and set the ventilation parameters of the air pressure buffer zone for auxiliary ventilation;

[0011] Step S3: Construct a three-dimensional underground topology model, monitor the regional environmental parameters of several grid partition units through the underground three-dimensional topology model, and calculate the ventilation compliance rate of different grid partition units based on the regional environmental parameters;

[0012] Step S4: Determine whether to perform topological dynamic reconstruction of the underground working space area of ​​the coal mine based on the ventilation compliance rate;

[0013] Step S5: Construct a fan power adjustment model to intelligently control the underground ventilation equipment, obtain the air volume and wind speed at different mining and tunneling depths during coal mine operations, and calculate the air pressure loss value during mining and tunneling.

[0014] Step S6: Deploy several booster stations between the underground ventilation equipment and the coal mine face, obtain the air volume compensation value based on the air pressure loss value, and then supply air volume to each mining and tunneling depth.

[0015] Furthermore, the process of dividing the underground working space of a coal mine into several grid partition units and setting up air pressure buffer zones at the junctions of the grid partition units includes:

[0016] A three-dimensional spatial scan of the underground working space of the coal mine is performed to obtain point cloud data corresponding to several roadways within the underground working space. The point cloud data is then imported into pre-deployed modeling software, and the underground working area of ​​the coal mine is divided into several grid partition units according to the roadway distribution.

[0017] Deploy downhole ventilation equipment at each grid partition unit and configure the start-up and shutdown conditions for the downhole ventilation equipment; when the start-up and shutdown conditions are met, start or shut down the downhole ventilation equipment; when the start-up and shutdown conditions are not met, do not perform any operation.

[0018] A pressure buffer zone is set at the junction of adjacent grid partition units at every two locations, and the corresponding operating parameters for the pressure buffer zone are set, including the transition chamber length, wind pressure gradient, and wind speed control range.

[0019] Furthermore, the equipment start-up and shutdown conditions include safety sub-conditions and equipment protection sub-conditions; wherein, when both safety sub-conditions and equipment protection sub-conditions are met, it indicates that the underground ventilation equipment meets the equipment start-up and shutdown conditions; otherwise, it indicates that the equipment start-up and shutdown conditions are not met.

[0020] The equipment start-up and shutdown conditions include safety sub-conditions and equipment protection sub-conditions; when both safety sub-conditions and equipment protection sub-conditions are met, it means that the underground ventilation equipment meets the equipment start-up and shutdown conditions; otherwise, it means that the equipment start-up and shutdown conditions are not met.

[0021] Furthermore, the process of dynamically changing the ventilation distribution mode of the grid zoning unit based on the real-time advance of the coal mine face, and setting the ventilation parameters of the air pressure buffer zone for auxiliary ventilation, includes:

[0022] A laser rangefinder is installed at the coal mine face to obtain the real-time advance of the face, denoted as L. This allows for the acquisition of the daily and cumulative advance of the face, also denoted as L0. -d and L 总 ;

[0023] Set a stage judgment threshold and a cumulative advancement threshold. The cumulative advancement threshold is denoted as η. The stage judgment thresholds include τ1, τ2 and τ3. Numerically, 0 < τ1 < τ2 < τ3 < η.

[0024] When L 总 When η < η, the ventilation distribution mode is: ventilation is carried out only through the downhole ventilation equipment;

[0025] Based on the daily advance L of the coal mine face -d Different ventilation allocation modes are determined based on different stage thresholds and the underground ventilation equipment is switched to different ventilation allocation modes. The different ventilation allocation modes include basic tunneling ventilation mode, enhanced tunneling ventilation mode, breakthrough preparation ventilation mode, and breakthrough execution ventilation mode.

[0026] When 0 < L -d When <τ1, switch to the basic tunneling ventilation mode;

[0027] When τ1≤L -d When <τ2, switch to enhanced tunneling ventilation mode;

[0028] When τ2≤L -d When <τ3, switch to through-ventilation preparation mode;

[0029] When τ3≤L -d When η < , switch to through-ventilation mode;

[0030] When L 总 When ≥η, the ventilation distribution mode is: while starting the underground ventilation equipment, the air pressure buffer zone is simultaneously started for auxiliary ventilation;

[0031] The ventilation parameters set for the air pressure buffer zone include pressure stabilization parameters, flow equalization parameters, and flow guidance parameters.

[0032] Furthermore, the process of constructing a downhole 3D topology model includes:

[0033] A full-coverage scan of the underground roadway environment corresponding to each grid partition unit is performed to obtain the three-dimensional coordinates and reflection intensity information of each grid partition unit as modeling information. The modeling information of each grid partition unit is processed by the point cloud registration algorithm to generate the underground spatial point cloud model of each grid partition unit. The underground spatial point cloud model is then converted into a roadway surface grid model.

[0034] Based on the roadway surface mesh model of each grid partition unit, the roadway centerline is extracted, the topological relationship between the roadway intersection or endpoint and the roadway edge is established, and then each grid partition unit is mapped to a subgraph in the topological graph, and the topological attributes of the grid partition unit are labeled.

[0035] Based on topological relationships and properties, the roadway surface mesh model of each grid partition unit is converted into a corresponding three-dimensional roadway topological model. The three-dimensional roadway topological model of each grid partition unit is corrected according to the real-time advance of the coal mine face. The three-dimensional roadway topological models of all grid partition units are integrated to construct an underground three-dimensional topological model that characterizes the entire underground space environment.

[0036] Furthermore, the process of monitoring regional environmental parameters of several grid partition units using a downhole 3D topology model and calculating the ventilation compliance rate of different grid partition units based on these regional environmental parameters includes:

[0037] Based on the three-dimensional topology model of the well, multi-source sensors are deployed in several grid partition units, and then environmental monitoring is carried out in each grid partition unit to obtain the regional environmental parameters of each grid partition unit, including regional gas concentration, regional dust concentration, regional CO concentration and regional ambient temperature.

[0038] Regional gas concentration, regional dust concentration, regional CO concentration, and regional ambient temperature are each treated as a monitoring item. The compliance index for each monitoring item is calculated, and a corresponding weighting weight is assigned to each monitoring item. Based on all regional environmental parameters under a grid partition unit, the ventilation compliance rate under the corresponding grid partition unit is calculated and denoted as Rv.

[0039] Furthermore, the process of determining whether to implement topological dynamic reconstruction of the underground working space area in a coal mine based on the ventilation compliance rate includes:

[0040] Set the reconstruction threshold and denote it as ψ;

[0041] For each grid partition unit, if Rv≥ψ, it means that the ventilation conditions of all roadways in the underground working space area of ​​the coal mine corresponding to the current grid partition unit meet the standards, and no operation is required; if Rv<ψ, it means that the ventilation conditions of the underground working space area of ​​the coal mine corresponding to the current grid partition unit do not meet the standards.

[0042] For grid partition units with substandard ventilation conditions, obtain the corresponding topology map of the grid partition unit, add virtual roadways to the topology map, adjust the partition boundaries of the grid partition unit, and split and change the roadway connection path to complete the topological dynamic reconstruction of the underground working space area of ​​the coal mine. After the topological dynamic reconstruction is completed, evaluate the ventilation compliance rate of the new grid partition unit until the ventilation compliance rate of the grid partition unit meets the requirements.

[0043] Furthermore, the process of constructing a fan power adjustment model to intelligently control underground ventilation equipment, obtaining the air volume and wind speed at different mining and tunneling depths during coal mine operations, and calculating the air pressure loss value during mining and tunneling includes:

[0044] Historical wind turbine operating data is acquired to build an operating condition database. The operating condition database is used to record the control data of the wind turbine at each operating power. An initial convolutional neural network model is built. The control data at each operating power is exported from the operating condition database to the initial convolutional neural network model. After model training, the initial convolutional neural network model is used to build a wind turbine power adjustment model.

[0045] The fan power adjustment model enables intelligent control of downhole ventilation equipment, including air volume replenishment and wind speed optimization.

[0046] Using the ground as the starting point of the coordinate system, the horizontal line of the ground as the X-axis, and the vertical line perpendicular to the horizontal line of the ground and pointing downwards as the Y-axis, a two-dimensional coordinate system is constructed to locate the coordinate position corresponding to each mining and tunneling depth. The coordinate position is denoted as P'=(x,y).

[0047] Record the air volume Q when the ventilation operation is performed at coordinate position P' = (x, y);

[0048] Record the wind speed V at coordinate position P' = (x, y) when the ventilation operation is performed;

[0049] By using the air volume and wind speed at the corresponding mining depth at coordinate position P'=(x,y), the wind pressure balance equation, and sensor data, the wind pressure loss value during mining is calculated and denoted as γ.

[0050] Furthermore, the process of deploying several levels of booster stations between the underground ventilation equipment and the coal mine face, obtaining air volume compensation values ​​based on air pressure loss values, and then supplying air volume to various mining and tunneling depths includes:

[0051] Obtain the vertical distance between the underground ventilation equipment and the coal mine face, obtain the booster station's booster operation distance, determine the number of booster stations to be deployed based on the vertical distance and the booster operation distance, and deploy several levels of booster stations at corresponding locations according to the number of deployments.

[0052] Set the target air volume corresponding to the current mining depth, and denote it as Q. 需 The wind resistance R' at the current mining depth is obtained, and then the theoretical wind pressure loss value corresponding to the target air volume is calculated. The theoretical wind pressure loss value is R'×Q. 需 2 ;

[0053] Based on the actual wind pressure loss value γ and the theoretical wind pressure loss value R'×Q 需 2 The wind pressure compensation value is calculated and denoted as ΔK. Then, ΔK = R' × Q 需 2 -γ;

[0054] When ΔK>0, pressure is supplemented to the booster station at the corresponding mining depth;

[0055] When ΔK≤0, no operation is performed;

[0056] The air volume compensation value is obtained from the wind pressure compensation value, and the air volume compensation value is denoted as Q. 补 Then Q 补 =ΔK.

[0057] Compared with the prior art, the beneficial effects of the present invention are:

[0058] 1. By dividing the underground working space of a coal mine into several grid partition units and setting up air pressure buffer zones at the junctions of these units, the ventilation distribution mode of the grid partition units is dynamically changed according to the real-time advance of the coal mining face. Ventilation parameters of the air pressure buffer zones are set for auxiliary ventilation. A three-dimensional underground topology model is constructed. The regional environmental parameters of several grid partition units are monitored through the underground three-dimensional topology model, and the ventilation compliance rate of different grid partition units is calculated based on the regional environmental parameters. The topology dynamic reconstruction of the underground working space is then performed based on the ventilation compliance rate. This achieves dynamic ventilation distribution, resolves the contradiction between static air volume distribution and dynamic mining, reduces gas accumulation in the underground working environment, and ensures the overall ventilation efficiency of the underground environment.

[0059] 2. By constructing a fan power adjustment model, intelligent control of underground ventilation equipment is achieved. This model obtains the air volume and velocity required for ventilation operations at different mining depths during coal mine operations, calculates the air pressure loss during mining, and deploys several booster stations between the underground ventilation equipment and the coal mine face. Based on the air pressure loss value, air volume compensation values ​​are obtained, thereby supplying air volume to various mining depths. This solves the problem of uneven air volume supply during coal mine operations as mining depth advances, and optimizes the problem of equipment energy waste. Attached Figure Description

[0060] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0061] like Figure 1 As shown, a ventilation optimization method for underground coal mine working environments includes the following steps:

[0062] Step S1: Divide the underground working space of the coal mine into several grid partition units, and set up air pressure buffer zones at the junctions of the grid partition units;

[0063] Step S2: Dynamically change the ventilation distribution mode of the grid partition unit according to the real-time advance of the coal mine face, and set the ventilation parameters of the air pressure buffer zone for auxiliary ventilation;

[0064] Step S3: Construct a three-dimensional underground topology model, monitor the regional environmental parameters of several grid partition units through the underground three-dimensional topology model, and calculate the ventilation compliance rate of different grid partition units based on the regional environmental parameters;

[0065] Step S4: Determine whether to perform topological dynamic reconstruction of the underground working space area of ​​the coal mine based on the ventilation compliance rate;

[0066] Step S5: Construct a fan power adjustment model to intelligently control the underground ventilation equipment, obtain the air volume and wind speed at different mining and tunneling depths during coal mine operations, and calculate the air pressure loss value during mining and tunneling.

[0067] Step S6: Deploy several booster stations between the underground ventilation equipment and the coal mine face, obtain the air volume compensation value based on the air pressure loss value, and then supply air volume to each mining and tunneling depth.

[0068] It should be further explained that, in the specific implementation process, the process of dividing the underground working space of the coal mine into several grid partition units and setting up air pressure buffer zones at the junctions of the grid partition units includes:

[0069] A three-dimensional spatial scan of the underground working space of the coal mine is performed to obtain point cloud data corresponding to several roadways within the underground working space. The point cloud data is then imported into pre-deployed modeling software, and the underground working area of ​​the coal mine is divided into several grid partition units according to the roadway distribution.

[0070] Obtain the location coordinates of each grid partition unit in the roadway and mark them to their respective grid partition units. Deploy underground ventilation equipment at each grid partition unit and configure the start and stop conditions of the underground ventilation equipment.

[0071] When the conditions for equipment start-up and shutdown are met, start or stop the underground ventilation equipment.

[0072] No operation is performed when the equipment start-up and shutdown conditions are not met;

[0073] The equipment start-up and shutdown conditions include safety sub-conditions and equipment protection sub-conditions; when both safety sub-conditions and equipment protection sub-conditions are met, it means that the underground ventilation equipment meets the equipment start-up and shutdown conditions; otherwise, it means that the equipment start-up and shutdown conditions are not met.

[0074] The safety sub-conditions specifically include gas concentration threshold, dust concentration threshold, and carbon monoxide concentration threshold; wherein, if at least one of the following is true, the safety sub-condition is determined to be true; otherwise, the safety sub-condition is determined to be false.

[0075] And perform the following corresponding equipment actions on the underground ventilation equipment;

[0076] When the real-time gas concentration exceeds the gas concentration threshold, the local fan group pressurization of the underground ventilation equipment is activated. Specific examples: For the mining face, if the real-time gas concentration is ≥0.8%, the local fan group pressurization of the mining face is activated; for the return airway, if the real-time gas concentration is ≥0.5%, the local fan group pressurization of the return airway is activated; for any location within a grid partition unit, if the real-time gas concentration is ≥1.0%, the local fan group pressurization at that location is activated.

[0077] When the real-time dust concentration exceeds the dust concentration threshold, the dust removal fan on the underground ventilation equipment is activated; For example, the real-time dust concentration is denoted as PM. 10 When PM 10 ≥20mg / m 3 At that time, start the dust collector;

[0078] When the real-time carbon monoxide concentration exceeds the carbon monoxide concentration threshold, the corresponding reverse ventilation device on the underground ventilation equipment is activated; specific example: real-time carbon monoxide concentration is denoted as N. CO When N CO When the concentration is ≥24ppm, activate the reverse ventilation system;

[0079] The equipment protection sub-conditions include motor temperature threshold, vibration intensity threshold, wind speed threshold, and current fluctuation threshold. Among them, if any one of the following conditions is met, the equipment protection sub-condition is determined to be met; otherwise, the equipment protection sub-condition is determined to be unmet.

[0080] When the equipment protection subcondition is not met, the following corresponding protection actions shall be performed on the underground ventilation equipment:

[0081] When the motor operating temperature is greater than or equal to the motor temperature threshold, the frequency of the underground ventilation equipment will be reduced to 30Hz. When the motor operating temperature of the underground ventilation equipment exceeds 140℃, the underground ventilation equipment will be shut down simultaneously.

[0082] When the motor vibration intensity is greater than or equal to the vibration intensity threshold, an early warning is triggered and the motor operates under reduced load.

[0083] When the ventilation speed is greater than or equal to the wind speed threshold, the underground ventilation equipment shall be shut down.

[0084] When the current fluctuation value is greater than or equal to the current fluctuation threshold, shut down the underground ventilation equipment and switch to the standby fan simultaneously.

[0085] A pressure buffer zone is set at the junction of adjacent grid partition units at every two locations, and the corresponding operating parameters for the pressure buffer zone are set, including the transition chamber length, wind pressure gradient, and wind speed control range.

[0086] It should be further explained that, in the specific implementation process, the process of dynamically changing the ventilation distribution mode of the grid zoning unit according to the real-time advance of the coal mine face, and setting the ventilation parameters of the air pressure buffer zone for auxiliary ventilation includes:

[0087] A laser rangefinder is installed at the coal mine face to obtain the real-time advance rate of the face. This real-time advance rate is denoted as L. This allows for the acquisition of the daily and cumulative advance rates of the coal mine face, which are also denoted as L0. -d and L 总 ;

[0088] Set stage judgment thresholds and cumulative progress thresholds;

[0089] The cumulative advancement threshold is denoted as η, and the stage determination threshold includes τ1, τ2 and τ3;

[0090] Numerically, 0 < τ1 < τ2 < τ3 < η;

[0091] When L 总 When η < η, the ventilation distribution mode is: ventilation is carried out only through the downhole ventilation equipment;

[0092] When L 总 When ≥η, the ventilation distribution mode is: while starting the underground ventilation equipment, the air pressure buffer zone is simultaneously started for auxiliary ventilation;

[0093] Specifically, when L 总 When <η, based on the daily advance L of the coal mine face. -d Different ventilation allocation modes are determined based on different stage thresholds and the underground ventilation equipment is switched to different ventilation allocation modes. The different ventilation allocation modes include basic tunneling ventilation mode, enhanced tunneling ventilation mode, breakthrough preparation ventilation mode, and breakthrough execution ventilation mode.

[0094] When 0 < L -d When <τ1, switch to the basic tunneling ventilation mode;

[0095] When τ1≤L -d When <τ2, switch to enhanced tunneling ventilation mode;

[0096] When τ2≤L -d When <τ3, switch to through-ventilation preparation mode;

[0097] When τ3≤L -d When <η, switch to through-ventilation mode.

[0098] The specific content of the basic tunneling ventilation mode is as follows: It is applicable to the initial advance period of coal mine mining face, and a single main local ventilation fan is activated to operate at a frequency below 40Hz. The auxiliary fans in the grid partition unit are kept on standby. The air volume of the working face is maintained above the minimum safe value, the wind speed is controlled at 0.25-0.5m / s, the wind speed in the return airway is controlled at ≤4m / s, the opening of the air window is adjusted to ≥80%, the air door is fully opened, and the ventilation resistance is reduced to the maximum extent.

[0099] The specific content of the enhanced tunneling ventilation mode is as follows: It is applicable to the high-efficiency advance period of coal mine face. Two main local ventilation fans are activated to run in parallel at a frequency of 45-50Hz, and dust removal fans and booster fan groups are started. At this time, the air volume of the working face is increased to 70%-90% of the maximum air volume, the wind speed is controlled at 0.5-1.0m / s, the wind speed of the return airway is controlled at ≤6m / s, and the fan opening is adjusted to 50%-70% of the maximum opening, thereby optimizing the airflow to the coal mine face.

[0100] The specific content of the ventilation mode for the preparation of the tunnel is as follows: It is applicable to the tunnel connection point (<50m) near the mining face in coal mines. The purpose is to pre-control the wind pressure balance at the tunnel connection point and isolate the risk area. At this time, the main local ventilation fan is switched to constant wind pressure continuous ventilation to maintain the wind pressure in the connection point area, and the backup fan is deployed at the connection point for hot standby. The air volume in the connection point area is reduced to below the preset safe tunnel ventilation volume value to reduce the impact of the tunnel connection. The difference in wind speed between adjacent tunnels is controlled to be ≤0.2m / s. Two-way sealed air doors are set on both sides of the connection point, with only adjustment holes left. The fan opening is set to 30% or less of the maximum opening.

[0101] The specific content of the ventilation mode is as follows: It is applicable to the period after the tunnel is connected. At this time, the main local ventilation fan is activated and adjusted according to the preset ventilation velocity curve, and the adjustment time is set to ≥10 minutes. The standby fan is started at the same time to compensate for the wind pressure fluctuation.

[0102] The ventilation parameters set for the pressure buffer zone specifically include pressure stabilization parameters, flow equalization parameters, and flow guidance parameters. Among them, the pressure stabilization parameters are used to adjust the pressure fluctuations caused by changes in ventilation distribution patterns between adjacent grid units; the flow equalization parameters are used to promote the uniform mixing of airflows from different sources and reduce turbulence; and the flow guidance parameters are used to compensate for local resistance changes caused by changes in roadway layout during the advancement of the coal mine face. Through the setting of pressure stabilization parameters, flow equalization parameters, and flow guidance parameters, the pressure buffer zone completes auxiliary ventilation.

[0103] It should be further explained that, in the specific implementation process, the process of constructing a three-dimensional underground topology model, monitoring the regional environmental parameters of several grid partition units through the underground three-dimensional topology model, and calculating the ventilation compliance rate of different grid partition units based on the regional environmental parameters includes:

[0104] A 3D laser scanner was used to sequentially complete a full-coverage scan of the underground roadway environment corresponding to each grid partition unit, thereby obtaining the 3D coordinates and reflection intensity information of each grid partition unit, which were then used as the modeling information for the corresponding grid partition unit.

[0105] The modeling information of each grid partition unit is processed by the point cloud registration algorithm to generate the underground spatial point cloud model corresponding to each grid partition unit. The underground spatial point cloud model of each grid partition unit is converted into the corresponding roadway surface grid model by the Alpha Shapes algorithm.

[0106] Based on the roadway surface mesh model of each grid partition unit, the roadway centerline is extracted, the topological relationship between the roadway intersection or endpoint and the roadway edge is established, and then each grid partition unit is mapped to a subgraph in the topological graph. The grid partition unit's cell ID, the location coordinates of each key node in the roadway, the roadway volume, and the connection relationship are labeled as the topological attributes of the grid partition unit.

[0107] Based on the obtained topological relationships and topological attributes, the roadway surface mesh model of each grid partition unit is converted into the corresponding roadway three-dimensional topological model. The roadway three-dimensional topological model of each grid partition unit is corrected according to the real-time advance of the coal mine face. When a new roadway is added, new topological nodes and topological edges are inserted into the topology map to expand the boundary of the grid partition unit and update the corresponding roadway three-dimensional topological model. The roadway three-dimensional topological models of all grid partition units are integrated to construct an underground three-dimensional topological model that represents the entire underground space environment.

[0108] Based on the three-dimensional topology model of the well, multi-source sensors are deployed in several grid partition units, and then environmental monitoring is carried out in each grid partition unit to obtain the regional environmental parameters corresponding to each grid partition unit. The regional environmental parameters include regional gas concentration, regional dust concentration, regional CO concentration and regional ambient temperature.

[0109] Regional methane concentration, regional dust concentration, regional CO concentration, and regional ambient temperature are each treated as a monitoring item. A compliance index is calculated for each monitoring item, and this compliance index is denoted as I. k The formula for calculating the compliance index is as follows:

[0110]

[0111] Among them, I k When the subscript k takes the value of 1, 2, 3 and 4, it corresponds to the regional gas concentration, regional dust concentration, regional CO concentration and regional ambient temperature in the monitoring items, respectively. The actual value in the calculation formula represents the actual value of the regional gas concentration, regional dust concentration, regional CO concentration and regional ambient temperature, respectively. The upper threshold and lower threshold represent the maximum allowable value and minimum allowable value of the regional gas concentration, regional dust concentration, regional CO concentration and regional ambient temperature, respectively.

[0112] Assign a corresponding weight to each monitoring item, and denote the weight as w. k k takes the values ​​1, 2, 3, and 4;

[0113] Based on all regional environmental parameters under a grid partition cell, the ventilation compliance rate under the corresponding grid partition cell is calculated. The ventilation compliance rate is denoted as Rv, and the formula for Rv is as follows:

[0114]

[0115] Among them, w k ∈(0,1), Rv∈(0,1), the sum of the weighted weights of each monitoring item included in all regional environmental parameters under the same grid partition unit is 1, that is, w1+w2+w3+w4=1.

[0116] It should be further explained that, in the specific implementation process, the process of determining whether to perform topological dynamic reconstruction of the underground working space area in coal mine based on the ventilation compliance rate includes:

[0117] Set a reconstruction threshold, and denote the reconstruction threshold as ψ;

[0118] For each grid partition unit, if Rv≥ψ, it means that the ventilation conditions of all roadways in the underground working space area of ​​the coal mine corresponding to the current grid partition unit meet the standards, and no operation is required; if Rv<ψ, it means that the ventilation conditions of the underground working space area of ​​the coal mine corresponding to the current grid partition unit do not meet the standards.

[0119] For grid partition units with substandard ventilation conditions, obtain the corresponding topology map of the grid partition unit, add virtual roadways to the topology map, adjust the partition boundaries of the grid partition unit, and split and change the roadway connection path to complete the topological dynamic reconstruction of the underground working space area of ​​the coal mine. After the topological dynamic reconstruction is completed, evaluate the ventilation compliance rate of the new grid partition unit until the ventilation compliance rate of the grid partition unit meets the requirements.

[0120] It should be further explained that, in the specific implementation process, the process of constructing a fan power adjustment model to intelligently control the underground ventilation equipment, obtaining the air volume and wind speed at different mining and tunneling depths during coal mine operations, and calculating the air pressure loss value during mining and tunneling includes:

[0121] Historical fan operation data is acquired, and the corresponding fan operating condition characteristics are obtained after data parsing of the historical fan operation data. An operating condition database is constructed based on all fan operating condition characteristics. The operating condition database is used to record the control data corresponding to each operating power of the fan of the underground ventilation equipment. An initial convolutional neural network model is constructed. The control data corresponding to each operating power is exported from the operating condition database to the initial convolutional neural network model. After model training, the initial convolutional neural network model is constructed into a fan power adjustment model.

[0122] Intelligent control of underground ventilation equipment is achieved using a fan power adjustment model;

[0123] The intelligent control of the fan specifically includes air volume replenishment and wind speed optimization;

[0124] When coal mining operations are carried out at the coal mine face, the air volume and wind speed corresponding to the ventilation equipment at different mining depths are obtained. The ground is used as the starting point of the coordinate system, and the starting point of the coordinate system is recorded as P0 = (0, 0). The horizontal line of the ground is used as the X-axis of the coordinate system, and the vertical line perpendicular to the horizontal line of the ground and pointing downwards is used as the Y-axis of the coordinate system.

[0125] Construct a two-dimensional coordinate system based on the starting point P0, the X-axis, and the Y-axis. Locate the coordinate position corresponding to each mining depth on the two-dimensional coordinate system and denot the coordinate position as P' = (x, y).

[0126] Record the air volume Q corresponding to the ventilation operation performed at coordinate position P' = (x, y);

[0127] Record the wind speed V corresponding to the ventilation operation at coordinate position P'=(x,y);

[0128] By using the air volume and wind speed at the corresponding mining depth at coordinate position P'=(x,y), the wind pressure balance equation, and sensor data, the wind pressure loss value during mining is calculated and denoted as γ.

[0129] For any segment of a tunnel or loop, the following relationship (wind pressure balance equation) exists:

[0130] H1-H2=∑(R×Q 2 );

[0131] Where H1 is the total pressure at the roadway entrance section, which includes the static pressure, dynamic pressure, and potential pressure at the roadway entrance section; H2 is the total pressure at the roadway exit section, ∑(R×Q) 2 ) represents the sum of all frictional resistance losses and local resistance losses in this section of the tunnel; R is the wind resistance of the tunnel, which is used to characterize the tunnel's own resistance to airflow and is related to the tunnel length, tunnel perimeter, and cross-sectional shape; Q is the air volume flowing through the tunnel.

[0132] The dynamic pressure in the total pressure at the tunnel entrance section is calculated using the wind speed V and air density ρ. Let the dynamic pressure be denoted as Pd, then Pd = 0.5 × ρ × V. 2 Static pressure is directly measured at both ends of the roadway entrance section and the roadway exit section. When there is a height difference Δz between the roadway entrance section and the roadway exit section, there is potential pressure: ρ×g×Δz, where g is the acceleration due to gravity.

[0133] The actual wind pressure value at coordinate position P' = (x, y) is obtained and denoted as Pr. The theoretical wind pressure value at P' = (x, y) is obtained from the wind pressure balance equation. The theoretical wind pressure value is H1-H2. Then the wind pressure loss value is expressed as: γ = |(H1-H2)-Pr|.

[0134] It should be further explained that, in the specific implementation process, the process of deploying several levels of booster stations between the underground ventilation equipment and the coal mine face, obtaining air volume compensation values ​​based on the air pressure loss values, and then supplying air volume to each mining depth includes:

[0135] Obtain the vertical distance between the underground ventilation equipment and the coal mine face, and denote the vertical distance as Hy;

[0136] Obtain the booster operation distance of the booster station and record it as Hp;

[0137] The number of booster stations to be deployed is obtained based on the vertical distance Hy and the booster operation distance Hp. The number of deployments is denoted as Num. Then, Num = Ceiling(Hy / Hp), where Ceiling() is the floor function. Several booster stations are deployed at several points corresponding to the number of deployments.

[0138] Set the target air volume corresponding to the current mining depth, and denote it as Q. 需 The wind resistance R' at the current mining depth is obtained, and then the theoretical wind pressure loss value corresponding to the target air volume is calculated. The theoretical wind pressure loss value is R'×Q. 需 2 ;

[0139] Based on the actual wind pressure loss value γ and the theoretical wind pressure loss value R'×Q 需 2 The wind pressure compensation value is calculated and denoted as ΔK. Then, ΔK = R' × Q 需 2 -γ;

[0140] When ΔK>0, pressure is supplemented to the booster station at the corresponding mining depth;

[0141] When ΔK≤0, no operation is performed;

[0142] The air volume compensation value is obtained from the wind pressure compensation value, and the air volume compensation value is denoted as Q. 补 Then Q 补 =ΔK, the air volume compensation value at a certain mining depth is the static pressure increase provided by the booster station deployed at the current mining depth, which is used to offset the air pressure loss.

[0143] It should be noted that through the process of precise control of air pressure, mines can achieve on-demand air supply in complex roadway networks, ensuring safe and efficient production in deep mining faces, adaptively adjusting air volume supply, solving the problem of equipment energy waste, and achieving efficient ventilation optimization for the underground working environment of coal mines.

[0144] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. A method for optimizing ventilation in underground coal mine working environments, characterized in that, Includes the following steps: Step S1: Divide the underground working space of the coal mine into several grid partition units, and set up air pressure buffer zones at the junctions of the grid partition units; Step S2: Dynamically change the ventilation distribution mode of the grid partition unit according to the real-time advance of the coal mine face, and set the ventilation parameters of the air pressure buffer zone for auxiliary ventilation; Step S3: Construct a three-dimensional underground topology model, monitor the regional environmental parameters of several grid partition units through the underground three-dimensional topology model, and calculate the ventilation compliance rate of different grid partition units based on the regional environmental parameters; Step S4: Determine whether to perform topological dynamic reconstruction of the underground working space area of ​​the coal mine based on the ventilation compliance rate; Step S5: Construct a fan power adjustment model to intelligently control the underground ventilation equipment, obtain the air volume and wind speed at different mining and tunneling depths during coal mine operations, and calculate the air pressure loss value during mining and tunneling. Step S6: Deploy several booster stations between the underground ventilation equipment and the coal mine face, obtain the air volume compensation value based on the air pressure loss value, and then supply air volume to each mining and tunneling depth.

2. The ventilation optimization method for underground coal mine working environment according to claim 1, characterized in that, The process of dividing the underground working space of a coal mine into several grid partition units and setting up air pressure buffer zones at the junctions of the grid partition units includes: A three-dimensional spatial scan of the underground working space of the coal mine is performed to obtain point cloud data corresponding to several roadways within the underground working space. The point cloud data is then imported into pre-deployed modeling software, and the underground working area of ​​the coal mine is divided into several grid partition units according to the roadway distribution. Deploy downhole ventilation equipment at each grid partition unit and configure the start-up and shutdown conditions for the downhole ventilation equipment; when the start-up and shutdown conditions are met, start or shut down the downhole ventilation equipment; when the start-up and shutdown conditions are not met, do not perform any operation. A pressure buffer zone is set at the junction of adjacent grid partition units at every two locations, and the corresponding operating parameters for the pressure buffer zone are set, including the transition chamber length, wind pressure gradient, and wind speed control range.

3. The ventilation optimization method for underground coal mine working environment according to claim 2, characterized in that, The equipment start-up and shutdown conditions include safety sub-conditions and equipment protection sub-conditions; when both safety sub-conditions and equipment protection sub-conditions are met, it means that the underground ventilation equipment meets the equipment start-up and shutdown conditions; otherwise, it means that the equipment start-up and shutdown conditions are not met. The specific safety sub-conditions include methane concentration threshold, dust concentration threshold, and carbon monoxide concentration threshold; depending on whether the safety sub-conditions are determined to be successful, it is selected whether to perform corresponding equipment actions on the downhole ventilation equipment. The equipment protection sub-conditions include motor temperature threshold, vibration intensity threshold, wind speed threshold, and current fluctuation threshold; based on whether the equipment protection sub-conditions are successfully determined, it is selected whether to perform corresponding protection actions on the downhole ventilation equipment.

4. The ventilation optimization method for underground coal mine working environment according to claim 3, characterized in that, The process of dynamically changing the ventilation distribution mode of the grid zoning unit based on the real-time advance of the coal mine face, and setting the ventilation parameters of the air pressure buffer zone for auxiliary ventilation, includes: A laser rangefinder is installed at the coal mine face to obtain the real-time advance of the face, denoted as L. This allows for the acquisition of the daily and cumulative advance of the face, also denoted as L0. -d and L 总 ; Set a stage judgment threshold and a cumulative advancement threshold. The cumulative advancement threshold is denoted as η. The stage judgment thresholds include τ1, τ2 and τ3. Numerically, 0 < τ1 < τ2 < τ3 < η. When L 总 When η < η, the ventilation distribution mode is: ventilation is carried out only through the downhole ventilation equipment; Based on the daily advance L of the coal mine face -d Different ventilation allocation modes are determined based on different stage thresholds and the underground ventilation equipment is switched to different ventilation allocation modes. The different ventilation allocation modes include basic tunneling ventilation mode, enhanced tunneling ventilation mode, breakthrough preparation ventilation mode, and breakthrough execution ventilation mode. When 0 < L -d When <τ1, switch to the basic tunneling ventilation mode; When τ1≤L -d When <τ2, switch to enhanced tunneling ventilation mode; When τ2≤L -d When <τ3, switch to through-ventilation preparation mode; When τ3≤L -d When η < , switch to through-ventilation mode; When L 总 When ≥η, the ventilation distribution mode is: while starting the underground ventilation equipment, the air pressure buffer zone is simultaneously started for auxiliary ventilation; The ventilation parameters set for the air pressure buffer zone include pressure stabilization parameters, flow equalization parameters, and flow guidance parameters.

5. A ventilation optimization method for underground coal mine working environments according to claim 4, characterized in that, The process of constructing a downhole 3D topology model includes: A full-coverage scan of the underground roadway environment corresponding to each grid partition unit is performed to obtain the three-dimensional coordinates and reflection intensity information of each grid partition unit as modeling information. The modeling information of each grid partition unit is processed by the point cloud registration algorithm to generate the underground spatial point cloud model of each grid partition unit. The underground spatial point cloud model is then converted into a roadway surface grid model. Based on the roadway surface mesh model of each grid partition unit, the roadway centerline is extracted, the topological relationship between the roadway intersection or endpoint and the roadway edge is established, and then each grid partition unit is mapped to a subgraph in the topological graph, and the topological attributes of the grid partition unit are labeled. Based on topological relationships and properties, the roadway surface mesh model of each grid partition unit is converted into a corresponding three-dimensional roadway topological model. The three-dimensional roadway topological model of each grid partition unit is corrected according to the real-time advance of the coal mine face. The three-dimensional roadway topological models of all grid partition units are integrated to construct an underground three-dimensional topological model that characterizes the entire underground space environment.

6. A ventilation optimization method for underground coal mine working environments according to claim 5, characterized in that, The process of monitoring regional environmental parameters of several grid partition units using a downhole 3D topology model and calculating the ventilation compliance rate of different grid partition units based on these parameters includes: Based on the three-dimensional topology model of the well, multi-source sensors are deployed in several grid partition units, and then environmental monitoring is carried out in each grid partition unit to obtain the regional environmental parameters of each grid partition unit, including regional gas concentration, regional dust concentration, regional CO concentration and regional ambient temperature. Regional gas concentration, regional dust concentration, regional CO concentration, and regional ambient temperature are each treated as a monitoring item. The compliance index for each monitoring item is calculated, and a corresponding weighting weight is assigned to each monitoring item. Based on all regional environmental parameters under a grid partition unit, the ventilation compliance rate under the corresponding grid partition unit is calculated and denoted as Rv.

7. A ventilation optimization method for underground coal mine working environments according to claim 6, characterized in that, The process of determining whether to implement topological dynamic reconstruction of the underground working space area in a coal mine based on the ventilation compliance rate includes: Set the reconstruction threshold and denote it as ψ; For each grid partition unit, if Rv≥ψ, it means that the ventilation conditions of all roadways in the underground working space area of ​​the coal mine corresponding to the current grid partition unit meet the standards, and no operation is required; if Rv<ψ, it means that the ventilation conditions of the underground working space area of ​​the coal mine corresponding to the current grid partition unit do not meet the standards. For grid partition units with substandard ventilation conditions, obtain the corresponding topology map of the grid partition unit, add virtual roadways to the topology map, adjust the partition boundaries of the grid partition unit, and split and change the roadway connection path to complete the topological dynamic reconstruction of the underground working space area of ​​the coal mine. After the topological dynamic reconstruction is completed, evaluate the ventilation compliance rate of the new grid partition unit until the ventilation compliance rate of the grid partition unit meets the requirements.

8. A ventilation optimization method for underground coal mine working environments according to claim 7, characterized in that, The process of constructing a fan power adjustment model to intelligently control underground ventilation equipment, obtaining the air volume and velocity at different mining depths during coal mine operations, and calculating the air pressure loss during mining and tunneling includes: Historical wind turbine operating data is acquired to build an operating condition database. The operating condition database is used to record the control data of the wind turbine at each operating power. An initial convolutional neural network model is built. The control data at each operating power is exported from the operating condition database to the initial convolutional neural network model. After model training, the initial convolutional neural network model is used to build a wind turbine power adjustment model. The fan power adjustment model enables intelligent control of downhole ventilation equipment, including air volume replenishment and wind speed optimization. Using the ground as the starting point of the coordinate system, the horizontal line of the ground as the X-axis, and the vertical line perpendicular to the horizontal line of the ground and pointing downwards as the Y-axis, a two-dimensional coordinate system is constructed to locate the coordinate position corresponding to each mining and tunneling depth. The coordinate position is denoted as P'=(x,y). Record the air volume Q when the ventilation operation is performed at coordinate position P' = (x, y); Record the wind speed V at coordinate position P' = (x, y) when the ventilation operation is performed; By using the air volume and wind speed at the corresponding mining depth at coordinate position P'=(x,y), the wind pressure balance equation, and sensor data, the wind pressure loss value during mining is calculated and denoted as γ.

9. A ventilation optimization method for underground coal mine working environments according to claim 8, characterized in that, The process of deploying several levels of booster stations between underground ventilation equipment and the coal mine face, obtaining air volume compensation values ​​based on air pressure loss values, and then supplying air volume to various mining depths includes: Obtain the vertical distance between the underground ventilation equipment and the coal mine face, obtain the booster station's booster operation distance, determine the number of booster stations to be deployed based on the vertical distance and the booster operation distance, and deploy several levels of booster stations at corresponding locations according to the number of deployments. Set the target air volume corresponding to the current mining depth, and denote it as Q. 需 The wind resistance R' at the current mining depth is obtained, and then the theoretical wind pressure loss value corresponding to the target air volume is calculated. The theoretical wind pressure loss value is R'×Q. 需 2 ; Based on the actual wind pressure loss value γ and the theoretical wind pressure loss value R'×Q 需 2 The wind pressure compensation value is calculated and denoted as ΔK. Then, ΔK = R' × Q 需 2 -γ; When ΔK>0, pressure is supplemented to the booster station at the corresponding mining depth; When ΔK≤0, no operation is performed; The air volume compensation value is obtained from the wind pressure compensation value, and the air volume compensation value is denoted as Q. 补 Then Q 补 =ΔK.

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