Ventilation optimization method for underground working environment of coal mine

Abstract

The invention discloses a ventilation optimization method for a coal mine underground operation environment, and relates to the technical field of coal mine operation safety, a coal mine underground operation space area is divided into a plurality of grid partition units, an air pressure buffer zone is arranged at the junction, and a ventilation distribution mode is dynamically changed according to the real-time propulsion amount of a coal mine excavation face, so that the ventilation performance of the coal mine underground operation environment is improved. Ventilation is assisted by the air pressure buffer zone, an underground three-dimensional topological model is constructed to monitor regional environment parameters, ventilation standard-reaching rates of different grid partition units are calculated according to the regional environment parameters, whether topological dynamic reconstruction of a coal mine underground operation space region is executed or not is judged, and a fan power adjustment model is constructed to conduct intelligent fan regulation and control. The method comprises the following steps: acquiring air volumes and air speeds at different mining and tunneling depths, calculating air pressure loss values at the corresponding mining and tunneling depths, deploying a plurality of stages of booster stations between underground ventilation equipment and a mining working face, acquiring air volume compensation values according to the air pressure loss values, and supplying air to each mining and tunneling depth so as to realize efficient ventilation optimization.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal mine operation safety, and particularly relates to a ventilation optimization method for a coal mine underground operation environment. BACKGROUND

[0002] Coal mine ventilation refers to a safety technical measure for conveying fresh air to a coal mine underground and discharging polluted air through certain technical means and equipment, so as to meet the requirements of breathing, dilution and discharge of harmful gas and dust of underground operation personnel and adjustment of underground climate, and is an important guarantee for safety production of the coal mine, which is directly related to the life safety of underground personnel and the normal production order of the coal mine.

[0003] The existing coal mine ventilation method has the following defects:

[0004] 1. The ventilation distribution mode with fixed air volume cannot adapt to the dynamic change of a coal mine mining face, resulting in gas accumulation in part of the space region of the coal mine underground operation, and affecting the overall ventilation efficiency of the underground environment.

[0005] 2. When the underground ventilation equipment is applied to coal mining, with the continuous increase of the mining and excavation depth, the phenomenon of unbalanced air supply appears during the coal mining.

[0006] Therefore, how to deal with the contradiction between static air volume distribution and dynamic mining, how to adaptively adjust the air supply according to the increase of the mining and excavation depth, and how to solve the problem of equipment energy waste to realize efficient ventilation optimization of the coal mine underground operation environment are the key and difficult problems in the technical field of coal mine operation safety. SUMMARY

[0007] In order to solve the above problems, the purpose of the present application is to provide a ventilation optimization method for a coal mine underground operation environment.

[0008] The purpose of the present application can be realized by the following technical scheme: a ventilation optimization method for a coal mine underground operation environment, comprising the following steps:

[0009] Step S1: dividing a coal mine underground operation space region into a plurality of grid partition units, and setting an air pressure buffer zone at the junction of the grid partition units;

[0010] Step S2: dynamically changing the ventilation distribution mode of the grid partition units according to the real-time advancing amount of the coal mine mining face, and setting the ventilation parameters of the air pressure buffer zone for auxiliary ventilation;

[0011] Step S3: constructing an underground three-dimensional topological model, monitoring the regional environment parameters of the plurality of grid partition units through the underground three-dimensional topological model, and calculating the ventilation compliance rate of different grid partition units based on the regional environment parameters;

[0012] Step S4: judging whether to perform the topological dynamic reconstruction of the coal mine underground operation space region according to the ventilation standard rate;

[0013] Step S5: constructing a fan power adjustment model to intelligently control the underground ventilation equipment, obtaining the air volume and air speed of the ventilation operation at different mining and tunneling depths during the coal mine operation, and calculating the air pressure loss value during the mining and tunneling;

[0014] Step S6: deploying several booster stations between the underground ventilation equipment and the coal mine mining face, obtaining the air volume compensation value according to the air pressure loss value, and then supplying air volume at each mining and tunneling depth.

[0015] Further, the process of dividing the coal mine underground operation space region into several grid partition units and setting the air pressure buffer zone at the junction of the grid partition units includes:

[0016] performing spatial three-dimensional scanning on the coal mine underground operation space region, and then obtaining the point cloud data corresponding to each of the several roadways in the coal mine underground operation space region, importing the point cloud data into the pre-deployed modeling software, and then dividing the coal mine underground operation region into several grid partition units according to the roadway distribution;

[0017] deploying underground ventilation equipment at each grid partition unit, and configuring the equipment start-stop conditions of the underground ventilation equipment; when the equipment start-stop conditions are met, starting or stopping the underground ventilation equipment; when the equipment start-stop conditions are not met, not performing any operation;

[0018] setting the air pressure buffer zone at the junction of each two adjacent grid partition units, and setting the corresponding operation parameters of the air pressure buffer zone, the operation parameters including the transition chamber length, the air pressure gradient, and the air speed control range.

[0019] Further, the equipment start-stop conditions include safety sub-conditions and equipment protection sub-conditions; when both the safety sub-conditions and the equipment protection sub-conditions are established, it means that the underground ventilation equipment meets the equipment start-stop conditions, otherwise, it means that the equipment start-stop conditions are not met;

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

[0021] Further, the process of dynamically changing the ventilation distribution mode of the grid partition unit according to the real-time advancing amount of the coal mine mining face, and setting the ventilation parameters of the air pressure buffer zone to assist ventilation includes:

[0022] A laser rangefinder is installed on the coal mining face to obtain the real-time advancement of the coal mining face through the laser rangefinder, which is recorded as L. The daily advancement and cumulative advancement of the coal mining face are then obtained, which are recorded as L -d and L 总 ;

[0023] Set the stage judgment threshold and the cumulative advancement threshold. The cumulative advancement threshold is recorded as η. The stage judgment thresholds include τ1, τ2 and τ3. The values ​​are 0<τ1<τ2<τ3<η;

[0024] When L 总 When η<η, the ventilation distribution mode is: ventilation operation is performed only through underground ventilation equipment;

[0025] According to the daily advance of the coal mining face L -d Different ventilation distribution modes are switched for underground ventilation equipment based on different stage judgment thresholds. The different ventilation distribution modes include basic excavation ventilation mode, enhanced excavation ventilation mode, breakthrough preparation ventilation mode, and breakthrough execution ventilation mode.

[0026] When 0<L -d When <τ1, switch to basic excavation 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 also started to assist ventilation;

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

[0032] Furthermore, the process of constructing the underground three-dimensional topological model includes:

[0033] Perform a full-coverage scan of the underground tunnel environment corresponding to each grid partition unit, obtain the three-dimensional coordinates and reflection intensity information of each grid partition unit as modeling information, process the modeling information of each grid partition unit through a point cloud registration algorithm, generate an underground spatial point cloud model of each grid partition unit, and convert the underground spatial point cloud model into a tunnel surface grid model;

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

[0035] According to the topological relationship and topological attributes, the tunnel surface grid model of each grid partition unit is converted into a corresponding tunnel three-dimensional topological model. The tunnel three-dimensional topological model of each grid partition unit is corrected according to the real-time advancement of the coal mine mining face. The tunnel three-dimensional topological models of all grid partition units are integrated to construct an underground three-dimensional topological model for representing the entire underground spatial environment.

[0036] Furthermore, the process of monitoring the regional environmental parameters of several grid partition units through the underground three-dimensional topological model and calculating the ventilation compliance rate of different grid partition units based on the regional environmental parameters includes:

[0037] Based on the underground 3D topological model, multi-source sensors are deployed in several grid partition units. Then, environmental monitoring is performed on each grid partition unit to obtain the regional environmental parameters of each grid partition unit. The regional environmental parameters include regional gas concentration, regional dust concentration, regional CO concentration, and regional ambient temperature.

[0038] The regional gas concentration, regional dust concentration, regional CO concentration and regional ambient temperature are respectively regarded as a monitoring item. The compliance index of each monitoring item is calculated. A corresponding weighted weight is set for 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 recorded as Rv.

[0039] Furthermore, the process of determining whether to perform dynamic topological reconstruction of the coal mine underground working space area according to the ventilation compliance rate includes:

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

[0041] For each grid partition unit, if Rv≥ψ, it means that the ventilation conditions of all tunnels in the underground working space area of ​​the coal mine corresponding to the current grid partition unit meet the standards, and no operation is performed. 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 the grid partition unit that does not meet the ventilation condition, the topological graph corresponding to the grid partition unit is obtained, a virtual roadway is added in the topological graph, the partition boundary of the grid partition unit is adjusted, and the roadway splitting and the roadway through path changing are performed, and then the topological dynamic reconstruction of the coal mine underground operation space area is completed, and after the topological dynamic reconstruction is completed, the ventilation compliance rate of the new grid partition unit is evaluated, until the ventilation compliance rate of the grid partition unit meets the requirements.

[0043] Further, the fan power adjustment model is constructed to intelligently control the underground ventilation equipment, the air volume and the air speed of the ventilation operation at different mining and tunneling depths during the coal mining are obtained, and the process of calculating the air pressure loss value during the mining and tunneling includes:

[0044] The historical fan operation data is obtained to construct a working condition database, the working condition database is used to record the control data of the fan at each operating power, an initial convolutional neural network model is constructed, the control data at each operating power is exported from the working condition database to the initial convolutional neural network model, and after the model training, the initial convolutional neural network model is constructed as a fan power adjustment model;

[0045] The fan intelligent control of the fan power adjustment model on the underground ventilation equipment includes air volume supply and air speed optimization;

[0046] The ground is taken as the starting point of the coordinate, the ground horizontal line is taken as the coordinate X axis, and the vertical line perpendicular to the ground horizontal line and downward is taken as the coordinate Y axis, a two-dimensional coordinate system is constructed for positioning the coordinate position corresponding to each mining and tunneling depth, and the coordinate position is recorded as P'=(x, y);

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

[0048] The air speed when the ventilation operation is performed at the coordinate position P'=(x, y) is recorded as V;

[0049] The air pressure loss value during the mining and tunneling is calculated and obtained through the air volume and the air speed at the coordinate position P'=(x, y) corresponding to the mining and tunneling depth, the air pressure balance equation and the sensor data, and the air pressure loss value at the coordinate position P'=(x, y) is recorded as γ.

[0050] Further, a plurality of booster stations are deployed between the underground ventilation equipment and the coal mining face, the air volume compensation value is obtained according to the air pressure loss value, and then the air volume supply at each mining and tunneling depth is performed.

[0051] Obtain the vertical distance between the underground ventilation equipment and the coal mine mining face, obtain the boosting operation distance of the boosting station, obtain the number of boosting stations to be deployed based on the vertical distance and the boosting operation distance, and deploy several levels of boosting stations at the corresponding points according to the number of deployments;

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

[0053] According to the actual wind pressure loss value γ and the theoretical wind pressure loss value R'×Q 需 2 , calculate the wind pressure compensation value, and record the wind pressure compensation value as ΔK, then ΔK=R'×Q 需 2 -γ;

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

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

[0056] The air volume compensation value is obtained according to the wind pressure compensation value, and the air volume compensation value is recorded as Q 补 , then Q 补 =ΔK.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] 1. By dividing the underground working space of the coal mine into several grid partition units and setting an air pressure buffer zone at the intersection of the grid partition units, the ventilation distribution mode of the grid partition units is dynamically changed according to the real-time advancement of the coal mine mining face, and the ventilation parameters of the air pressure buffer zone are set for auxiliary ventilation. An underground three-dimensional topological model is constructed. The regional environmental parameters of several grid partition units are monitored through the underground three-dimensional topological model, and the ventilation compliance rate of different grid partition units is obtained based on the regional environmental parameters. According to the ventilation compliance rate, it is determined whether to execute the dynamic topological reconstruction of the underground working space area of ​​the coal mine, thereby realizing dynamic ventilation distribution, solving the contradiction between static air volume distribution and dynamic mining, reducing the gas accumulation phenomenon in the underground working environment, and ensuring the overall ventilation efficiency of the underground environment.

[0059] 2. By constructing a fan power adjustment model, the fan of the underground ventilation equipment is intelligently controlled to obtain the air volume and wind speed for ventilation operations at different mining and excavation depths during coal mine operations, and the wind pressure loss value during mining and excavation is calculated. Several levels of booster stations are deployed between the underground ventilation equipment and the coal mine mining face. The air volume compensation value is obtained according to the wind pressure loss value, and then the air volume is supplied at each mining and excavation depth. This solves the problem of uneven air volume supply during coal mine operations as the mining depth advances, and optimizes the problem of equipment energy waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 Flowchart of the present invention. DETAILED DESCRIPTION

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

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

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

[0064] Step S3: constructing an underground three-dimensional topological model, monitoring regional environmental parameters of a plurality of grid partition units through the underground three-dimensional topological model, and calculating the ventilation compliance rate of different grid partition units based on the regional environmental parameters;

[0065] Step S4: determining whether to perform dynamic topology reconstruction of the coal mine underground working space area according to the ventilation compliance rate;

[0066] Step S5: Constructing a fan power adjustment model to perform intelligent fan control on underground ventilation equipment, obtaining the air volume and wind speed for ventilation operations at different mining and excavation depths during coal mine operations, and calculating the wind pressure loss value during mining and excavation;

[0067] Step S6: deploy several levels of booster stations between the underground ventilation equipment and the coal mine mining face, obtain air volume compensation values ​​according to the wind pressure loss values, and then supply air volume to each mining excavation 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 a number of grid partition units and setting air pressure buffer zones at the intersections of the grid partition units includes:

[0069] Conduct a three-dimensional spatial scan of the underground coal mine working space to obtain point cloud data corresponding to several tunnels within the underground coal mine working space. Import the point cloud data into pre-deployed modeling software to divide the underground coal mine working space into several grid partition units according to the distribution of tunnels.

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

[0071] Start or stop the underground ventilation equipment when the equipment start and stop conditions are met;

[0072] When the equipment start / stop conditions are not met, no operation is performed;

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

[0074] The safety sub-condition specifically includes a gas concentration threshold, a dust concentration threshold, and a carbon monoxide concentration threshold; wherein, if at least one of the following conditions holds true: the real-time gas concentration in the grid cell is greater than or equal to the gas concentration threshold, or the real-time dust concentration is greater than or equal to the dust concentration threshold, or the real-time carbon monoxide concentration is greater than or equal to the carbon monoxide concentration threshold, then the safety sub-condition is determined to be met; otherwise, the safety sub-condition is determined to be not met;

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

[0076] When the real-time gas concentration is greater than the gas concentration threshold, the local fan group pressurization of the underground ventilation equipment is activated; for example: 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 air lane, if the real-time gas concentration is ≥0.5%, the local fan group pressurization of the return air lane is activated; for any position in the grid partition unit, when the real-time gas concentration is ≥1.0%, the local fan group pressurization at the corresponding position is activated;

[0077] When the real-time dust concentration is greater than the dust concentration threshold, the dust removal fan on the underground ventilation equipment is started; for example: the real-time dust concentration is recorded as PM 10 , when PM 10 ≥20 mg / m 3 When the dust removal machine is started;

[0078] When the real-time carbon monoxide concentration is greater than the carbon monoxide concentration threshold, the corresponding anti-wind device on the underground ventilation equipment is started; specific example: the real-time carbon monoxide concentration is recorded as N CO , when N CO When the value is ≥24ppm, start the anti-wind device;

[0079] The equipment protection sub-condition includes a motor temperature threshold, a vibration intensity threshold, a wind speed threshold, and a current fluctuation threshold; wherein, when the motor operating temperature within the grid partition unit is greater than or equal to the motor temperature threshold, or the motor vibration intensity is greater than or equal to the vibration intensity threshold, or the ventilation wind speed is greater than or equal to the wind speed threshold, or the current fluctuation value is greater than or equal to the current fluctuation threshold, any one of which is true, then the equipment protection sub-condition is determined to be true; otherwise, the equipment protection sub-condition is determined to be false;

[0080] When the equipment protection sub-condition is not met, the following corresponding protection actions are performed on the underground ventilation equipment:

[0081] When the motor operating temperature is greater than or equal to the motor temperature threshold, the underground ventilation equipment will be reduced to 30Hz. When the motor operating temperature of the underground ventilation equipment exceeds 140°C, 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 runs at a reduced load;

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

[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 backup fan simultaneously;

[0085] An air pressure buffer zone is set at the intersection of every two adjacent grid division units, and operating parameters corresponding to the air pressure buffer zone are set. The operating parameters include the length of the transition chamber, the wind pressure gradient, and the wind speed control range.

[0086] It should be further explained that, in the specific implementation process, the ventilation distribution mode of the grid partition unit is dynamically changed according to the real-time advancement of the coal mining face, and the ventilation parameters of the air pressure buffer zone are set for auxiliary ventilation. The process includes:

[0087] A laser rangefinder is installed on the coal mining face to obtain the real-time advancement of the coal mining face through the laser rangefinder, and the value of the real-time advancement is recorded as L. The daily advancement and cumulative advancement of the coal mining face are then obtained and recorded as L respectively. -d and L 总 ;

[0088] Set the stage determination threshold and cumulative advancement threshold;

[0089] The cumulative advancement threshold is recorded as η, and the stage determination thresholds include τ1, τ2 and τ3;

[0090] In terms of numerical value, 0<τ1<τ2<τ3<η;

[0091] When L 总 When η<η, the ventilation distribution mode is: ventilation operation is performed only through underground 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 also started to assist ventilation;

[0093] Specifically, when L 总 <η, according to the daily advance L of the coal mining face -d Different ventilation distribution modes are switched for underground ventilation equipment based on different stage judgment thresholds. The different ventilation distribution modes include basic excavation ventilation mode, enhanced excavation ventilation mode, breakthrough preparation ventilation mode, and breakthrough execution ventilation mode.

[0094] When 0<L -d When <τ1, switch to basic excavation 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 suitable for the initial advancement period of the coal mine mining face, and a single main local fan is activated to operate at a frequency of less than 40Hz, and the auxiliary fans in the grid partition unit remain 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 of the return air lane is controlled at ≤4m / s, the wind window opening is adjusted to ≥80%, and the damper is fully opened to minimize ventilation resistance;

[0099] The enhanced tunneling ventilation mode is specifically designed to be used during the efficient advancement period of the coal mining face. Two main local ventilation fans are activated in parallel at a frequency of 45-50 Hz, and the dust removal fan and booster fan group are started. At this time, the air volume at the working face is increased to 70%-90% of the maximum air volume, the wind speed is controlled at 0.5-1.0 m / s, the wind speed in the return air lane is controlled at ≤6 m / s, and the fan opening is adjusted to 50%-70% of the maximum opening, thereby optimizing the air flow to the coal mining face.

[0100] The specific content of the through-through preparation ventilation mode is as follows: it is applicable to coal mine mining faces close to the tunnel through-through point (<50m), with the purpose of pre-controlling the wind pressure balance at the tunnel through-through point and isolating the risk area. At this time, the main local fan switches to constant wind pressure continuous ventilation to maintain the wind pressure in the through-through area, and the standby fan is activated and deployed at the through-through point; the air volume in the through-through area is reduced to below the preset safe through-through volume value to reduce the instantaneous impact of the through-through, and the difference in wind speed between adjacent tunnels is controlled to ≤0.2m / s. Two-way sealed dampers are set on both sides of the through-through point, leaving only adjustment holes, and the fan opening is set to 30% or less of the maximum opening;

[0101] The specific content of the through-ventilation mode is: it is applicable to the period after the tunnel is through. At this time, the main local ventilation fan is enabled to adjust according to the preset through-air velocity curve, and the adjustment time is set to ≥10 minutes. The standby fan is started simultaneously to compensate for wind pressure fluctuations.

[0102] The ventilation parameters set for the pressure buffer zone specifically include pressure stabilization parameters, flow balancing parameters and diversion parameters; among them, the pressure stabilization parameters are used to adjust the pressure fluctuations caused by changes in the ventilation distribution mode between adjacent grid partition units; the flow balancing parameters are used to promote the uniform mixing of airflows from different sources and reduce turbulence; the diversion parameters are used to compensate for the local resistance changes caused by changes in the tunnel layout when the coal mining face advances. By setting the pressure stabilization parameters, flow balancing parameters and diversion 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 3D underground topological model, monitoring the regional environmental parameters of several grid partition units through the 3D underground topological model, and calculating the ventilation compliance rate of different grid partition units based on the regional environmental parameters includes:

[0104] A 3D laser scanner is used to complete a full-coverage scan of the underground tunnel environment corresponding to each grid partition unit in turn, thereby obtaining the 3D coordinates and reflection intensity information corresponding to each grid partition unit, which is used as the modeling information of the corresponding grid partition unit;

[0105] The modeling information of each grid partition unit is processed through 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 tunnel surface grid model through the Alpha Shapes algorithm.

[0106] Based on the roadway surface mesh model of each grid partition unit, the roadway centerline is extracted, and the topological relationship between the roadway intersection or endpoint and the roadway edge is established. Then, each grid partition unit is mapped into a subgraph in the topological graph, and the unit ID of the grid partition unit, the position coordinates of each key node in the roadway, the roadway volume and the connection relationship are marked as the topological attributes of the grid partition unit;

[0107] Based on the obtained topological relationships and topological attributes, the roadway surface grid model of each grid partition unit is converted into a corresponding roadway 3D topological model. The roadway 3D topological model of each grid partition unit is modified according to the real-time advancement of the coal mining face. When a new tunneling roadway is added, new topological nodes and topological edges are inserted into the topological map, the boundaries of the grid partition unit are expanded, and the corresponding roadway 3D topological model is updated. The roadway 3D topological models of all grid partition units are integrated to construct an underground 3D topological model used to represent the entire underground spatial environment.

[0108] Based on the underground 3D topological model, multi-source sensors are deployed in several grid partition units. Then, environmental monitoring is performed on each grid partition unit to obtain the corresponding regional environmental parameters for each grid partition unit. The regional environmental parameters include regional gas concentration, regional dust concentration, regional CO concentration, and regional ambient temperature.

[0109] Take the regional gas concentration, regional dust concentration, regional CO concentration and regional ambient temperature as a monitoring item respectively, calculate the compliance index of each monitoring item, and record the compliance index as I k , then the calculation formula of the compliance index is as follows:

[0110]

[0111] Among them, I k When the subscript k is 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, and the upper and lower thresholds represent the maximum and minimum allowable values ​​of the regional gas concentration, regional dust concentration, regional CO concentration, and regional ambient temperature, respectively.

[0112] Set the corresponding weight for each monitoring item and record the weight as w k , k takes values ​​of 1, 2, 3 and 4;

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

[0114]

[0115] Among them, w k ∈(0, 1), Rv∈(0, 1), the cumulative 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 dynamic topological reconstruction of the coal mine underground working space area based on the ventilation compliance rate includes:

[0117] Set the reconstruction threshold and record it as ψ;

[0118] For each grid partition unit, if Rv≥ψ, it means that the ventilation conditions of all tunnels in the underground working space area of ​​the coal mine corresponding to the current grid partition unit meet the standards, and no operation is performed. 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, the topological map corresponding to the grid partition units is obtained, and virtual lanes are added to the topological map. The partition boundaries of the grid partition units are adjusted, and lane splitting and lane through-path changes are performed to complete the topological dynamic reconstruction of the underground working space area of ​​the coal mine. After the dynamic reconstruction of the topology is completed, the ventilation compliance rate is evaluated in the new grid partition units until the ventilation compliance rate of the grid partition units 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 fans of underground ventilation equipment, obtaining the air volume and wind speed for ventilation operations at different mining and excavation depths during coal mine operations, and calculating the wind pressure loss value during mining and excavation includes:

[0121] Obtain historical fan operation data, perform data analysis on the historical fan operation data to obtain corresponding fan operating condition characteristics, build a working condition database based on all the fan operating condition characteristics, the working condition database is used to record the corresponding control data of the fans of the underground ventilation equipment at each operating power, build an initial convolutional neural network model, export the corresponding control data at each operating power from the working condition database to the initial convolutional neural network model, and after model training, construct the initial convolutional neural network model into a fan power adjustment model;

[0122] The fan power adjustment model is used to intelligently control the fans of underground ventilation equipment;

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

[0124] When the coal mine tunneling face performs the coal mine operation, the corresponding air volume and air speed of the underground ventilation equipment performing the ventilation operation at different mining tunneling depths are obtained, the ground is taken as the coordinate starting point, and the coordinate starting point is recorded as P0=(0, 0); the ground horizontal line is taken as the coordinate X axis, and the vertical line perpendicular to the ground horizontal line and downward is taken as the coordinate Y axis;

[0125] A two-dimensional coordinate system is constructed according to the coordinate starting point P0, the coordinate X axis and the coordinate Y axis, the coordinate position corresponding to each mining tunneling depth is located on the two-dimensional coordinate system, and the coordinate position is recorded as P'=(x, y);

[0126] The corresponding air volume Q of the coordinate position P'=(x, y) performing the ventilation operation is recorded;

[0127] The corresponding air speed V of the coordinate position P'=(x, y) performing the ventilation operation is recorded;

[0128] The air pressure loss value during mining and tunneling is calculated by the air volume and air speed of the coordinate position P'=(x, y) corresponding to the mining tunneling depth, the air pressure balance equation and the sensor data, and the air pressure loss value of the coordinate position P'=(x, y) is recorded as γ;

[0129] For any section of roadway or loop, there is a relationship (air pressure balance equation) as follows:

[0130] H1-H2=∑(R×Q 2 );

[0131] Wherein, H1 is the total pressure of the roadway entrance section, which includes the static pressure, dynamic pressure and potential pressure of the roadway entrance section, H2 is the total pressure of the roadway exit section, ∑(R×Q 2 ) represents the sum of all friction resistance losses and local resistance losses in the section of roadway, R is the air resistance of the roadway, which is used to represent the hindering characteristics of the roadway to the air flow, which is related to the length of the roadway, the perimeter of the roadway, the shape of the section, and Q is the air volume flowing through the roadway;

[0132] Wherein, the dynamic pressure in the total pressure of the roadway entrance section is calculated by the air speed V and the air density ρ, and the dynamic pressure is recorded as Pd, then Pd=0.5×ρ×V 2 , the static pressure is directly measured at the two ends of the roadway entrance section and the roadway exit section, and when there is a height difference Δz between the roadway entrance section and the roadway exit section, there is a potential pressure: ρ×g×Δz, g is the acceleration of gravity;

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

[0134] It should be further explained that, in the specific implementation process, several levels of booster stations are deployed between the underground ventilation equipment and the coal mine mining face, and the air volume compensation value is obtained according to the wind pressure loss value, and then the air volume is supplied to each mining depth. The process includes:

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

[0136] Obtain the boosting operation distance of the boosting 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 boosting operation distance Hp. The number of deployments is recorded as Num, and then Num = Ceiling(Hy / Hp), where Ceiling() is a rounding function. Several levels of booster stations are deployed at several points corresponding to the deployment number.

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

[0139] According to the actual wind pressure loss value γ and the theoretical wind pressure loss value R'×Q 需 2 , calculate the wind pressure compensation value, and record the wind pressure compensation value as ΔK, then ΔK=R'×Q 需 2 -γ;

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

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

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

[0143] It should be noted that through the process of fine control of the wind pressure, the mine can realize on-demand air supply in the complex roadway network, guarantee the safe and efficient production of deep mining surface, adaptively adjust the air supply, solve the problem of waste of equipment energy consumption, and realize efficient ventilation optimization of the coal mine underground working environment.

[0144] The above examples are only used to illustrate the technical method of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that the technical method of the present application can be modified or equivalently replaced without departing from the spirit and scope of the technical method of the present application.

Claims

1. A ventilation optimization method for an underground coal mine working environment, characterized in that: The following steps are involved: Step S1: Divide the underground working space of the coal mine into a number of grid partition units, and set air pressure buffer zones at the intersections of the grid partition units; Step S2: Dynamically changing the ventilation distribution mode of the grid partition unit according to the real-time advancement of the coal mining face, and setting the ventilation parameters of the air pressure buffer zone for auxiliary ventilation; Step S3: constructing an underground three-dimensional topological model, monitoring regional environmental parameters of a plurality of grid partition units through the underground three-dimensional topological model, and calculating the ventilation compliance rate of different grid partition units based on the regional environmental parameters; Step S4: determining whether to perform dynamic topology reconstruction of the coal mine underground working space area according to the ventilation compliance rate; Step S5: Constructing a fan power adjustment model to perform intelligent fan control on underground ventilation equipment, obtaining the air volume and wind speed for ventilation operations at different mining and excavation depths during coal mine operations, and calculating the wind pressure loss value during mining and excavation; Step S6: deploy several levels of booster stations between the underground ventilation equipment and the coal mine mining face, obtain air volume compensation values ​​according to the wind pressure loss values, and then supply air volume to each mining excavation depth.

2. A ventilation optimization method for an 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 a number of grid partition units and setting air pressure buffer zones at the intersections of the grid partition units includes: Conduct a three-dimensional spatial scan of the underground coal mine working space to obtain point cloud data corresponding to several tunnels within the underground coal mine working space. Import the point cloud data into pre-deployed modeling software to divide the underground coal mine working space into several grid partition units according to the distribution of tunnels. Deploy underground ventilation equipment in each grid unit and configure the equipment start and stop conditions for the underground ventilation equipment; when the equipment start and stop conditions are met, start or stop the underground ventilation equipment; when the equipment start and stop conditions are not met, do nothing; An air pressure buffer zone is set at the intersection of every two adjacent grid division units, and operating parameters corresponding to the air pressure buffer zone are set. The operating parameters include the length of the transition chamber, the wind pressure gradient, and the wind speed control range.

3. A ventilation optimization method for an underground coal mine working environment according to claim 2, characterized in that: The equipment start / stop conditions include safety sub-conditions and equipment protection sub-conditions; when both the safety sub-conditions and the equipment protection sub-conditions are met, it means that the underground ventilation equipment meets the equipment start / stop conditions; otherwise, it means that the equipment start / stop conditions are not met; The safety sub-conditions specifically include a gas concentration threshold, a dust concentration threshold, and a carbon monoxide concentration threshold; and depending on whether the safety sub-conditions are successfully determined, whether to execute corresponding equipment actions on the underground 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 underground ventilation equipment.

4. A ventilation optimization method for an underground coal mine working environment according to claim 3, characterized in that: The process of dynamically changing the ventilation distribution mode of the grid partition unit according to the real-time advancement of the coal mining face and setting the ventilation parameters of the air pressure buffer zone for auxiliary ventilation includes: A laser rangefinder is installed on the coal mining face to obtain the real-time advancement of the coal mining face through the laser rangefinder, which is recorded as L. The daily advancement and cumulative advancement of the coal mining face are then obtained, which are recorded as L -d and L 总 ; Set the stage judgment threshold and the cumulative advancement threshold. The cumulative advancement threshold is recorded as η. The stage judgment thresholds include τ1, τ2 and τ3. The values ​​are 0<τ1<τ2<τ3<η; When L 总 When η<η, the ventilation distribution mode is: ventilation operation is performed only through underground ventilation equipment; According to the daily advance of the coal mining face L -d Different ventilation distribution modes are switched for underground ventilation equipment based on different stage judgment thresholds. The different ventilation distribution modes include basic excavation ventilation mode, enhanced excavation ventilation mode, breakthrough preparation ventilation mode, and breakthrough execution ventilation mode. When 0<L -d When <τ1, switch to basic excavation 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 also started to assist ventilation; The ventilation parameters set for the air pressure buffer zone include pressure stabilization parameters, flow equalization parameters, and diversion parameters.

5. A ventilation optimization method for an underground coal mine working environment according to claim 4, characterized in that: The process of building a 3D downhole topology model includes: Perform a full-coverage scan of the underground tunnel environment corresponding to each grid partition unit, obtain the three-dimensional coordinates and reflection intensity information of each grid partition unit as modeling information, process the modeling information of each grid partition unit through a point cloud registration algorithm, generate an underground spatial point cloud model of each grid partition unit, and convert the underground spatial point cloud model into a tunnel surface grid model; Based on the roadway surface mesh model of each grid partition unit, the roadway centerline is extracted, and the topological relationship between the roadway intersection or endpoint and the roadway edge is established. Then, each grid partition unit is mapped into a subgraph in the topological graph, and the topological attributes of the grid partition unit are annotated. According to the topological relationship and topological attributes, the tunnel surface grid model of each grid partition unit is converted into a corresponding tunnel three-dimensional topological model. The tunnel three-dimensional topological model of each grid partition unit is corrected according to the real-time advancement of the coal mine mining face. The tunnel three-dimensional topological models of all grid partition units are integrated to construct an underground three-dimensional topological model for representing the entire underground spatial environment.

6. A ventilation optimization method for an underground coal mine working environment according to claim 5, characterized in that: The process of monitoring the regional environmental parameters of several grid partition units through the underground three-dimensional topological model and calculating the ventilation compliance rate of different grid partition units based on the regional environmental parameters includes: Based on the underground 3D topological model, multi-source sensors are deployed in several grid partition units. Then, environmental monitoring is performed on each grid partition unit to obtain the regional environmental parameters of each grid partition unit. The regional environmental parameters include regional gas concentration, regional dust concentration, regional CO concentration, and regional ambient temperature. The regional gas concentration, regional dust concentration, regional CO concentration and regional ambient temperature are respectively regarded as a monitoring item. The compliance index of each monitoring item is calculated. A corresponding weighted weight is set for 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 recorded as Rv.

7. A ventilation optimization method for an underground coal mine working environment according to claim 6, characterized in that: The process of determining whether to perform dynamic topological reconstruction of the coal mine underground working space area based on the ventilation compliance rate includes: Set the reconstruction threshold and record it as ψ; For each grid partition unit, if Rv≥ψ, it means that the ventilation conditions of all tunnels in the underground working space area of ​​the coal mine corresponding to the current grid partition unit meet the standards, and no operation is performed. 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, the topological map corresponding to the grid partition units is obtained, and virtual lanes are added to the topological map. The partition boundaries of the grid partition units are adjusted, and lane splitting and lane through-path changes are performed to complete the topological dynamic reconstruction of the underground working space area of ​​the coal mine. After the dynamic reconstruction of the topology is completed, the ventilation compliance rate is evaluated in the new grid partition units until the ventilation compliance rate of the grid partition units meets the requirements.

8. A ventilation optimization method for an underground coal mine working environment according to claim 7, characterized in that: The process of constructing a fan power adjustment model to intelligently control the fans of underground ventilation equipment, obtaining the air volume and wind speed required for ventilation operations at different mining depths during coal mine operations, and calculating the wind pressure loss during mining and tunneling includes: Historical wind turbine operating data is obtained to build a working condition database. The working condition database is used to record the control data of the wind turbine at each operating power. An initial convolutional neural network model is constructed. The control data at each operating power is exported from the working condition database and input into the initial convolutional neural network model. After model training, the initial convolutional neural network model is constructed into a wind turbine power adjustment model. The fan power adjustment model performs intelligent fan control on underground ventilation equipment, including air volume supply and wind speed optimization; With the ground as the starting point, the ground level as the X-axis, and the vertical line perpendicular to the ground level and pointing downward as the Y-axis, a two-dimensional coordinate system is constructed to locate the coordinate position corresponding to each mining excavation depth. The coordinate position is recorded as P' = (x, y); Record the air volume Q when performing ventilation operation at coordinate position P'=(x, y); Record the wind speed V when performing ventilation operation at coordinate position P'=(x, y); The wind pressure loss value during mining excavation is calculated by using the wind volume and wind speed at the mining excavation depth corresponding to the coordinate position P'=(x, y), the wind pressure balance equation and sensor data, and the wind pressure loss value at the coordinate position P'=(x, y) is recorded as γ.

9. A ventilation optimization method for an underground coal mine working environment according to claim 8, characterized in that: Several booster stations are deployed between the underground ventilation equipment and the coal mining face. The air volume compensation value is obtained based on the wind pressure loss value, and the air volume supply process at each mining depth includes: Obtain the vertical distance between the underground ventilation equipment and the coal mine mining face, obtain the boosting operation distance of the boosting station, obtain the number of boosting stations to be deployed based on the vertical distance and the boosting operation distance, and deploy several levels of boosting stations at the corresponding points according to the number of deployments; Set the target air volume corresponding to the current mining depth and record it as Q 需 , obtain the wind resistance R' corresponding to the current mining depth, and then calculate the theoretical wind pressure loss value corresponding to the target air volume. The theoretical wind pressure loss value is R'×Q 需 2 ; According to the actual wind pressure loss value γ and the theoretical wind pressure loss value R'×Q 需 2 , calculate the wind pressure compensation value, and record the wind pressure compensation value as ΔK, then ΔK=R'×Q 需 2 -γ; When ΔK>0, the pressure of the booster station at the corresponding mining depth is supplemented; When ΔK≤0, no operation is performed; The air volume compensation value is obtained according to the wind pressure compensation value, and the air volume compensation value is recorded as Q 补 , then Q 补 =ΔK.

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