Multi-face fan duct variable resistance voltage regulation method and system

Abstract

The present application belongs to the technical field of tunnel construction ventilation, and relates to a multi-face tunnel variable resistance pressure regulating method and system. The target required air volume at the tunnel face is obtained according to the environmental parameters; the total friction resistance coefficient of the branch air duct is obtained according to the target required air volume; the inherent friction resistance coefficient of the branch air duct is obtained by controlling the flexible air cavity to exert pulse disturbance on the airflow in the branch air duct; the first additional friction resistance coefficient of the branch air duct is obtained according to the total friction resistance coefficient and the inherent friction resistance coefficient; the second additional friction resistance coefficient of the branch air duct is obtained by controlling the annular inflatable rib lining to exert sweep frequency disturbance on the airflow in the branch air duct; the resistance coefficient deviation between the first additional friction resistance coefficient and the second additional friction resistance coefficient is obtained; and the tunnel face air duct is subjected to variable resistance pressure regulation according to the resistance coefficient deviation. The present application can reduce the imbalance of the air duct environment caused by the cross-tunnel airflow interference and external environmental transient disturbance.

Description

Technical Field

[0001] This invention belongs to the field of tunnel construction ventilation technology, specifically relating to a method and system for variable resistance pressure regulation of ventilation ducts in multi-face tunnels. Background Technology

[0002] In multi-face parallel construction scenarios in underground engineering, the ventilation system is a core infrastructure for ensuring the safety of workers and maintaining construction efficiency. Its core function is to continuously supply fresh air to each face, dilute harmful gases such as CO, NOx, and methane generated by blasting, and reduce dust concentration. Currently, multi-face ventilation mainly adopts the technical route of "fan frequency conversion regulation + air damper / valve air distribution". This route originated from single-face construction scenarios. In multi-face parallel operations, the resistance of each branch will change dynamically with the working conditions (such as dust adhesion after blasting leading to increased roughness of the ventilation duct wall and increased resistance; vehicle passage causing local ventilation duct cross-section contraction and a sudden increase in resistance). However, current multi-face ventilation technology that relies on damper linkage or simple frequency conversion cannot quickly respond to dynamic resistance changes such as sudden changes in dust / gas after blasting and air leakage due to ventilation duct folds, which can easily lead to airflow imbalance across the faces. Summary of the Invention

[0003] The technical problem to be solved by this invention is that existing multi-face ventilation technology cannot quickly respond to dynamic resistance changes such as sudden changes in dust / gas after blasting and air leakage due to folds in the ventilation duct, which easily leads to airflow imbalance across the working faces.

[0004] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: A first aspect provides a method for variable resistance pressure regulation in a multi-face ventilation duct, comprising the following steps: collecting a first environmental parameter inside the branch ventilation duct and a second environmental parameter at the working face; obtaining the target air volume requirement at the working face based on the first environmental parameter and the second environmental parameter; the branch ventilation duct is provided with a flexible air cavity and an annular inflatable rib; acquiring a first real-time pressure difference inside the branch ventilation duct; obtaining the total friction resistance coefficient of the branch ventilation duct based on the first real-time pressure difference and the target air volume requirement; controlling the flexible air cavity to apply a pulse disturbance to the airflow inside the branch ventilation duct; acquiring the second real-time pressure difference and the first real-time air volume during the pulse disturbance process inside the branch ventilation duct; and obtaining the target air volume requirement based on the first real-time pressure difference and the target air volume requirement. The inherent frictional resistance coefficient of the branch duct is obtained by using the second real-time pressure difference and the first real-time air volume; the first additional frictional resistance coefficient of the branch duct is obtained based on the total frictional resistance coefficient and the inherent frictional resistance coefficient; the annular inflatable rib is controlled to apply a frequency sweeping disturbance to the airflow in the branch duct; the third real-time pressure difference and the second real-time air volume are obtained during the frequency sweeping disturbance process in the branch duct; the second additional frictional resistance coefficient of the branch duct is obtained based on the third real-time pressure difference and the second real-time air volume; the resistance coefficient deviation between the first additional frictional resistance coefficient and the second additional frictional resistance coefficient is obtained; and the resistance pressure of the face duct is adjusted according to the resistance coefficient deviation.

[0005] Secondly, a multi-face ventilation duct variable resistance pressure regulation system is provided, comprising: The environmental parameter acquisition module is used to collect the first environmental parameters inside the branch ventilation duct and the second environmental parameters at the working face; the branch ventilation duct is equipped with a flexible air cavity and an annular inflatable rib liner; The air volume demand acquisition module is used to acquire the target air volume demand at the working face based on the first environmental parameter and the second environmental parameter. The first differential pressure acquisition module is used to acquire the first real-time differential pressure inside the branch ventilation duct; The first resistance coefficient acquisition module is used to obtain the total friction resistance coefficient of the branch duct based on the first real-time pressure difference and the target required air volume. The first control module is used to control the flexible air cavity to apply pulse disturbances to the airflow in the branch duct. The second differential pressure acquisition module is used to acquire the second real-time differential pressure during the pulse disturbance process in the branch duct. The first air volume acquisition module is used to acquire the first real-time air volume during the pulse disturbance process in the branch air duct. The second resistance coefficient acquisition module is used to acquire the inherent friction resistance coefficient of the branch duct based on the second real-time pressure difference and the first real-time air volume. The third resistance coefficient acquisition module is used to obtain the first additional friction resistance coefficient of the branch duct based on the total friction resistance coefficient and the inherent friction resistance coefficient. The second control module is used to control the annular inflatable rib to apply a sweep frequency disturbance to the airflow in the branch duct. The third differential pressure acquisition module is used to acquire the third real-time differential pressure during the frequency sweep disturbance process inside the branch duct; The second air volume acquisition module is used to acquire the second real-time air volume during the frequency sweeping disturbance process in the branch air duct. The fourth resistance coefficient acquisition module is used to obtain the second additional friction resistance coefficient of the branch duct based on the third real-time pressure difference and the second real-time air volume. The drag coefficient deviation acquisition module is used to acquire the drag coefficient deviation between the first additional friction drag coefficient and the second additional friction drag coefficient. The variable resistance voltage regulation module is used to adjust the resistance and voltage of the ventilation duct at the working face according to the deviation of the resistance coefficient.

[0006] Thirdly, a computer device is provided, comprising a memory, a processor, and a transceiver connected in sequence, wherein the memory is used to store a computer program, the transceiver is used to send and receive data, and the processor is used to read the computer program and execute a multi-face wind tunnel variable resistance voltage regulation method as described in the first aspect.

[0007] Fourthly, a computer-readable storage medium is provided, on which instructions are stored, which, when executed on a computer, perform a multi-face wind tunnel variable resistance pressure regulation method as described in the first aspect.

[0008] Fifthly, a computer program product containing instructions is provided, which, when executed on a computer, causes the computer to perform a multi-face wind tunnel variable resistance and pressure regulation method as described in the first aspect; the computer includes: a general-purpose computer, a special-purpose computer, or a programmable device.

[0009] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention realizes the direct adjustment of the internal resistance of the wind tunnel through the whole process technical architecture of "environmental parameter perception - dynamic calculation of target air volume demand - dual component coordinated adjustment (flexible air cavity + annular inflatable rib) - in-situ resistance system identification - resistance coefficient deviation correction", thereby reducing the imbalance of the internal environment of the wind tunnel caused by cross-face airflow interference and transient disturbances of the external environment. Specifically, by combining the internal and external environmental parameters of the ventilation duct, the target air volume required at the working face is obtained, providing a target reference for adjusting the internal resistance of the ventilation duct. Based on the target reference, the total frictional resistance coefficient of the ventilation duct is calculated, transforming the "ventilation demand" into a "resistance coefficient target". Through the linkage of pulse disturbance of the flexible air cavity and frequency sweep disturbance of the annular inflatable rib, the inherent frictional resistance coefficient of the ventilation duct and the additional resistance coefficient of the resistance adjustment device are separated, achieving precise matching of "demand-resistance coefficient-air volume". Finally, closed-loop adjustment is performed based on the resistance coefficient deviation, realizing precise adjustment of internal pressure according to the real-time internal and external resistance environment of each ventilation duct branch, thereby reducing the imbalance of the internal environment of the ventilation duct caused by cross-working face airflow interference and transient disturbances of the external environment. Attached Figure Description

[0010] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart illustrating a multi-face wind tunnel variable resistance pressure regulation method provided in Embodiment 1 of the present invention. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. The illustrative embodiments and descriptions of this invention are for illustrative purposes only and are not intended to limit the invention. The embodiments described below are some, but not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0012] In the following description, numerous specific details are set forth to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known structures, materials, or methods are not specifically described to avoid obscuring the invention. Unless otherwise specified, the materials, instruments, and reagents used in the following embodiments are commercially available. Unless otherwise specified, the techniques used in the embodiments are conventional methods well known to those skilled in the art.

[0013] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0014] Example 1: A method for variable resistance pressure regulation in a multi-face ventilation duct, including... Figure 1 The following steps are shown: Step 1: Collect the first environmental parameters inside the branch ventilation duct and the second environmental parameters at the working face, and obtain the target air volume requirement at the working face based on the first and second environmental parameters.

[0015] Prior to this, environmental sensing devices need to be installed inside each branch ventilation duct and at the working face of each branch ventilation duct. An annular inflatable rib is installed inside each branch ventilation duct, and a parallel flexible air cavity is connected to the outside of each branch ventilation duct. Specifically, the environmental sensing devices to be deployed inside each branch ventilation duct include: a wind speed sensor, a barometric pressure sensor, a dust sensor, a carbon monoxide sensor, and a methane sensor. The environmental sensing devices to be deployed at each working face include: a UWB positioning module and an internal combustion engine operating condition acquisition unit. The installation location and method of each sensor are described below.

[0016] 1. Wind speed sensor Multiple wind speed sensors are installed axially at intervals (e.g., 5m) on the inner wall of the branch duct. The installation positions of the wind speed sensors should be close to the horizontal centerline of the inner wall of the duct, avoiding the interface of the branch duct, the bend end, the top condensation area, and the bottom dust accumulation area. In addition, the probes of the wind speed sensors should be facing the airflow direction to directly collect the wind speed in the mainstream area.

[0017] In addition, the wind speed sensor is fixed with an "L-shaped metal bracket + clamp", and the bracket height is 1 / 3 of the inner diameter of the wind duct (e.g., if the inner diameter of the branch wind duct is 1.2m, the bracket height is 0.4m) to ensure that the probe is in the mainstream airflow area; the probe of the wind speed sensor is equipped with a dust cover (a metal filter with a 0.5mm aperture, which can be disassembled and cleaned regularly) to prevent dust from clogging the ultrasonic transmitting / receiving unit and affecting the measurement accuracy.

[0018] 2. Barometric pressure sensor A pair of air pressure sensors are installed downstream (5m) of the bifurcation point between the branch duct and the main duct, and at the end of the branch duct (3m from the working face) to monitor the pressure difference fluctuations at both ends of the branch duct caused by the adjustment of the annular inflatable rib and the duct folds.

[0019] In addition, the pressure tap of the pressure sensor is made of stainless steel (8mm in diameter), with the end machined at a 45° bevel (facing the airflow direction to reduce pressure fluctuations caused by airflow impact). The inner wall of the pressure tap is polished (roughness Ra≤0.8μm to avoid dust accumulation and blockage). The pressure tap of the pressure sensor is connected to the pressure sensor through a silicone tube (temperature resistant -40-120℃, inner diameter 4mm). The length of the silicone tube is ≤2m (to reduce pressure transmission delay, delay time ≤100ms). A micro filter (pore size 0.2μm, to filter dust) is installed on the tube.

[0020] 3. Dust sensor Dust sensors are installed at the "branching point (5m)" and "end point (5m)" of the branch duct to form a "front-end-end" dual monitoring system, reflecting the diffusion and settling patterns of dust in the branch duct.

[0021] In addition, the dust sensor is installed using a "snap-on mounting bracket". The bracket is connected to the inner wall of the air duct by bolts (bolt spacing ≤10cm) to ensure that the sensor does not shift under the impact of airflow (displacement ≤1mm to avoid affecting acoustic signal acquisition). A "dust baffle" (5mm away from the probe and tilted at 45°) is added to the outside of the dust sensor probe to prevent large dust particles (diameter >10μm) from directly hitting the probe, while not preventing small dust particles (PM2.5 / PM10) from entering the monitoring area.

[0022] 4. Carbon monoxide sensor, methane sensor A carbon monoxide sensor and a methane sensor are installed "3m before the end of the branch duct" (close to the working face, to monitor the concentration of pollutants). The probes of the carbon monoxide sensor and the methane sensor face downstream of the airflow to ensure that the pollutants discharged from the working face can preferentially contact the sensors and reduce response delay.

[0023] The carbon monoxide and methane sensors are mounted using a flange-type installation. They are fixed by pre-drilled mounting holes in the duct wall (the diameter of which matches the sensor flange). An oil-resistant rubber sealing ring (IP67 waterproof rating) is installed between the flange and the duct wall to prevent gas leakage inside the duct. The carbon monoxide and methane sensors have built-in gas flow channels (20mm in length and 5mm in inner diameter). Ventilation holes (3mm in diameter) are opened at both ends of the channel to ensure that the gas inside the duct can flow naturally into the sensor detection chamber.

[0024] 5. UWB positioning module A UWB positioning module is deployed below the arch of the working face (2m from the excavation face and 0.8m from the arch). A second base station is deployed on the steel support 5m behind the working face to form a "dual base station positioning network". This ensures that the positioning signals of the two base stations can cover the working area (the core range of personnel / equipment activities) at the working face and 5m behind it.

[0025] In addition, the UWB positioning module is fixed to the steel support with "clamps and bolts", the base station antenna is vertically downward (to avoid impact from flying rocks during blasting), and the antenna is unobstructed from the working area at the face (≥1m from the nearest equipment); the UWB positioning module uses the 3.5-6.5GHz frequency band (to avoid the frequency bands of other wireless devices in the tunnel, such as walkie-talkies at 400MHz), and the distance between the base station and the integrated environment station and equipment condition acquisition device is ≥0.5m (to avoid electromagnetic interference).

[0026] 6. Internal Combustion Equipment Operating Condition Data Acquisition Device The main data acquisition unit is deployed on the steel support on the right side of the working face (2m from the excavation face, 1.2m high), and a backup data acquisition unit (redundant backup) is deployed 3m behind the working face. The internal combustion equipment operating condition data acquisition unit described in this embodiment is mainly used to collect the power of the internal combustion equipment in real time (as model parameters for subsequent internal combustion equipment sub-models). It connects to the CAN bus interface of the internal combustion equipment via an intrinsically safe CAN to RS485 module (explosion-proof rating ExiaIMa) to directly read the power of the internal combustion equipment.

[0027] In addition, the internal combustion equipment operating condition data collector adopts a "wall-mounted installation" and is equipped with a stainless steel protective box (thickness ≥2mm, collision protection). The protective box has reserved ventilation holes (hole diameter 5mm, to prevent the data collector from overheating).

[0028] 7. Annular inflatable rib liner Annular inflatable ribs are installed at the bifurcation point (5-10m) between the branch duct and the main duct, and at the end of the working face (5m). The annular inflatable ribs are made of aging-resistant rubber and the inflation pressure (0-0.8MPa) is controlled by an intrinsically safe solenoid valve. When power is lost, the valve automatically depressurizes to the fully open state (safe reset) to adjust the equivalent hydraulic diameter of the duct.

[0029] 8. Flexible air cavity A flexible air chamber is connected in parallel at the bifurcation point (≤2m) between the branch duct and the main duct. The volume of the flexible air chamber is 1-3% of the equivalent volume of the main duct's rated flow rate (e.g., 0.3-0.6m³ when the main flow rate is 2000m³ / min). The internal pressure of the flexible air chamber is controlled by an electronically controlled proportional valve, forming an "airflow capacitance" to reduce cross-face airflow coupling oscillations.

[0030] Based on the above 8 sensors, the first environmental parameters collected in this step include: carbon monoxide mass, dust concentration, methane emission, and dust concentration; the second environmental parameters collected in this step include: real-time number of personnel, real-time number of internal combustion equipment, and power of internal combustion equipment.

[0031] It should be noted that after collecting the first environmental parameters inside the branch ventilation duct and the second environmental parameters at the working face, Kalman filtering can be performed on the first and second environmental parameters, and 3σ outlier removal processing can be performed on the first and second environmental parameters after Kalman filtering.

[0032] Furthermore, the specific method for obtaining the target air volume requirement at the working face based on the first environmental parameter and the second environmental parameter is as follows: Step 1.1: Establish five basic air volume calculation sub-models (personnel ventilation sub-model, internal combustion equipment sub-model, blasting purification sub-model, gas dilution sub-model, and dust dilution sub-model) for different operating scenarios, and output the basic air volume of a single working face according to the "take the largest value" principle. Q base .

[0033] 1. Personnel ventilation sub-model The expression for the personnel ventilation sub-model is: Q P = k P × N × Q 0. Among them, Q P The required air volume for ventilation of personnel k P For personnel safety factor, N This represents the real-time number of personnel at the working face. Q 0 represents the minimum air volume required for a single person. It should be noted that: (1) In engineering scenarios involving personnel safety, such as ventilation during multi-face tunnel construction and underground mining operations, the "personnel safety factor" k PThis is a core parameter in processes such as airflow calculation and safety protection design. Essentially, it's a safety redundancy coefficient set to mitigate the discrepancy between theoretical calculations and actual risks. By multiplying the theoretical airflow (which meets basic personnel needs) by a coefficient greater than 1, it reserves extra airflow to address unforeseen risks such as fluctuations in personnel numbers, individual differences, and sudden environmental changes, ensuring personnel are always in a ventilated environment that meets safety standards. During tunnel construction, the number of personnel may temporarily increase (e.g., by temporarily adding maintenance personnel or collaborative work teams). If the airflow is calculated based on the "real-time minimum number of personnel," the newly added personnel will be placed in an environment with insufficient airflow, thus compromising personnel safety. k P The reserved extra air volume can cover short-term personnel increases. Furthermore, the personnel safety factor... k P It is not a fixed value and needs to be dynamically adjusted based on the risk level of the work scenario, regulatory requirements, and environmental complexity. However, the personnel safety factor... k P The value of the safety factor must comply with industry safety standards and avoid falling below the minimum safety redundancy. The "Detailed Design Specifications for Ventilation of Highway Tunnels" (JTG / T3370.1-2018) clearly states that "the calculation of personnel ventilation volume should consider a safety redundancy of at least 1.2 times to ensure that the per capita ventilation volume is not less than 2.5 m³ / min under extreme conditions." Therefore, when the number of personnel is stable (≤10 people), the personnel safety factor... k P A value of 1.2 to 1.3 is acceptable. When the number of personnel fluctuates (10-20 people), the personnel safety factor is... k P A value of 1.3 to 1.5 is acceptable; when the number of people is large (>20), the personnel safety factor should be... k P 1.5~1.8 can be selected. (2) Minimum air volume required per person Q According to the "Detailed Design Rules for Ventilation of Highway Tunnels" and "Safety Regulations for Coal Mines", the standard is usually 3m³ / min·person, which means that each person needs no less than 3m³ of fresh air per minute.

[0034] 2. Internal Combustion Equipment Sub-model The expression for the internal combustion equipment sub-model is: .in, This represents the total ventilation required for internal combustion equipment. The heat dissipation coefficient of internal combustion equipment. P i This represents the real-time power of a single internal combustion engine. i Number the internal combustion equipment. M The total number of all operating internal combustion equipment (obtained via UWB positioning module). This refers to the air volume required per unit power of a single internal combustion engine. It should be noted that: (1) Heat dissipation coefficient of internal combustion equipment The baseline values ​​must strictly refer to industry standards, equipment manuals, and test data. For example, the "Technical Specification for Highway Tunnel Construction" (JTG / T3660-2020) clearly states that in the calculation of ventilation volume for internal combustion equipment, the heat dissipation coefficient of diesel internal combustion equipment should be taken as 0.06-0.07 m³ / (min·kW), and that of gasoline internal combustion equipment should be taken as 0.07-0.08 m³ / (min·kW).

[0035] (2) Air volume required per unit power of a single internal combustion engine This information can be obtained by consulting the technical manual provided by the equipment manufacturer or the "Technical Specifications for Highway Tunnel Construction". For example, the "Technical Specifications for Highway Tunnel Construction" (JTG / T3660-2020) clearly states that in the calculation of ventilation volume for internal combustion equipment, 3. Explosive Purification Sub-model The expression for the blast purification sub-model is: Q B ( t ) =k B ×M g / ( C lim ×t ).in, Q B Air volume is required for blasting purification. k B For the blasting safety redundancy factor, M g The mass of harmful gases produced by the blasting C lim For harmful permissible concentrations, t This refers to the purification timeframe. It should be noted that: (1) Explosive safety redundancy k B This safety factor is set to address risks such as fluctuations in the generation of harmful gases, delays in the ventilation system, and monitoring errors during blasting. Essentially, it ensures that harmful gases can still be effectively diluted even in extreme circumstances by increasing the theoretical ventilation volume. The "Safety Regulations for Blasting" (GB6722-2014) clearly states: [The text abruptly ends here, likely due to an incomplete sentence or missing information.] k B The value should not be lower than 1.8, and should be increased to above 2.0 in high-risk areas. In engineering practice, conventional tunnel blasting... k B =2.0, high-gas tunnel take k B =2.2, for shallow urban tunnels (where vibration and gas diffusion must be strictly controlled) k B =1.9.

[0036] (2) The harmful gases produced by blasting mainly include carbon monoxide, nitrogen oxides, and sulfur dioxide. Among them, carbon monoxide is the most toxic and is produced in the largest quantity. It is the main component used to calculate the mass of harmful gases produced by blasting. M g The core indicator. Therefore, in this embodiment, the mass of harmful gases in the blasting purification sub-model. M g The permissible concentration of harmful substances is taken as the mass of carbon monoxide gas. Furthermore, the mass of harmful gases... M g The calculation formula is M g = K g × Q .in, K g The amount of harmful gases generated per unit of explosive is determined by the type of explosive (obtained from the explosive's factory inspection report). Q This refers to the charge amount for a single-cycle blasting operation.

[0037] (3) Permissible concentration of harmful gases C lim This is the safety threshold for personnel entering the working face, and must be strictly determined according to national mandatory standards. Similarly, in this embodiment, the permissible concentration of harmful gases in the blasting purification sub-model is taken as the permissible concentration of carbon monoxide. According to the "Occupational Exposure Limits for Hazardous Factors in the Workplace" (GBZ2.1-2019), the permissible concentration of carbon monoxide can be ≤24ppm (approximately 30mg / m³).

[0038] (4) Purification time limit t This refers to the ventilation system reducing the concentration of harmful gases to the permissible concentration after blasting. C lim The following are the longest allowed times (usually) t The ventilation and purification time at the tunnel face after blasting shall not exceed 15 minutes, and the time for the concentration of harmful gases to drop to a safe level shall be ≤5 minutes. The Technical Specification for Highway Tunnel Construction (JTG / T3660-2020) stipulates that "the ventilation and purification time at the tunnel face after blasting shall not exceed 15 minutes, and the time for the concentration of harmful gases to drop to a safe level shall be ≤5 minutes".

[0039] 4. Gas dilution sub-model The expression for the gas diluent model is: Q G =100× q G / C G .in, Q G Air volume required for gas dilutionq G For gas emission volume, C G This refers to the permissible concentration of methane gas. It should be noted that: (1) Gas emission q G It refers to the amount of gas released from the goaf to the working face per unit time. Its magnitude directly determines the ventilation and dilution requirements, and is collected by gas sensors.

[0040] (2) Permissible concentration of gas C G This is the critical value for ensuring operational safety, directly based on mandatory national standards. According to the "Coal Mine Safety Regulations" (2022 edition), the permissible gas concentration during face operations is... C G ≤0.5%.

[0041] 5. Dust dilution sub-model The expression for the dust dilution submodel is: .in, Q D Air volume required for dust dilution The initial dust concentration (obtained by a dust sensor). To allow for dust concentration, V D The effective volume of the working face. t This refers to the dust concentration collection time. It should be noted that the effective volume of the working face refers to the volume of the space requiring ventilation and purification; its calculation formula is: V D = S D × L D ,in, S D The average cross-sectional area of ​​the working face. L D The effective length of the working face.

[0042] The required ventilation volume for personnel was calculated using the five basic air volume calculation sub-models described above. Q P Total ventilation required for internal combustion equipment Q E Explosion purification requires air volume Q B Gas dilution requires air volume Q G Air volume required for dust dilution Q D Ventilation volume required for personnel Q P Total ventilation required for internal combustion equipmentQ E Explosion purification requires air volume Q B Gas dilution requires air volume Q G Air volume required for dust dilution Q D The maximum value in the output is the basic air volume required for a single working face. Q base It should be noted that the required air volume for ventilation of personnel is... Q P Total ventilation required for internal combustion equipment Q E Explosion purification requires air volume Q B Gas dilution requires air volume Q G Air volume required for dust dilution Q D The maximum value in the range is used as the basic air volume requirement for a single working face. Q base The purpose is to ensure that the ventilation system can cover all potential risk scenarios and protect personnel safety and operational efficiency. Essentially, it involves calculating the basic air volume required under different scenarios such as personnel breathing, equipment heat dissipation, blast purification, and gas / dust dilution, and finally selecting the maximum value as the basic air volume required for a single working face. This avoids safety accidents (such as oxygen deficiency or excessive harmful gases) caused by insufficient air volume in a single scenario, while ensuring that the ventilation system has the redundancy to cope with the risks of multiple scenarios.

[0043] Step 1.2: Determine the basic required air volume Q base Minimum required air volume as per specifications Q spec The maximum value between these two values ​​is taken as the actual air volume required at a single face. Q actrul .

[0044] It should be noted that: (1) Specify the minimum required air volume Q spec According to the "Detailed Design Rules for Ventilation of Highway Tunnels", the air volume corresponding to the cross-sectional area × 0.25 m / s wind speed is taken.

[0045] (2) Determine the basic required air volume Q base Minimum required air volume as per specifications Q spec The maximum value between these two values ​​is taken as the actual air volume required at a single face. Q actrulThe aim is to simultaneously consider both the actual needs of the scenario and the safety requirements of industry standards, ensuring that the airflow can adapt to the airflow requirements at different stages of construction while meeting basic safety guarantees, and avoiding safety risks caused by insufficient consideration of a single dimension. Specifically: on the one hand, the airflow calculated based on the actual scenario needs usually considers specific factors such as personnel breathing, equipment heat dissipation, dilution of harmful gases, and dilution of dust, thus conforming to the airflow requirements of the actual working conditions; on the other hand, it is based on the minimum airflow threshold that must be met for specific types of projects as stipulated by industry standards, meeting the most basic requirements for operational safety. Step 1.3: Utilize the altitude correction coefficient and tunnel band coefficient to calculate the actual required airflow. Q actrul After making corrections, the target air volume required at the single face is obtained.

[0046] Introducing an altitude correction factor k Alt (When the altitude is >1000m, for every 100m increase, k Alt Increase by 0.02), tunnel slope coefficient k Slope (When the slope is greater than 5%, for every 1% increase, k Slope Increase by 0.01). It should be noted that: (1) According to IEC60664-1 and GB7251.2-2023 standards, when the altitude is 1000 meters or below, the standard requirements are met by default and no correction is required. Altitude correction factor k Alt =1.

[0047] (2) Tunnel slope coefficient k Slope The value varies depending on the tunnel traction method and length. For internal combustion engine traction, the tunnel length is typically 401-1000 meters, and the gradient coefficient... k Slope The base value is taken as 0.9; the tunnel length is between 1001 and 4000 meters, and the gradient coefficient is... k Slope The base value is taken as 0.9; the tunnel length exceeds 4000 meters, and the gradient coefficient... k Slope The base value is 0.75.

[0048] Ultimately, the target air volume at the single face is... Q req = max { Q base , Q spec}× k Alt × k Slope.

[0049] Step 2: Obtain the first real-time pressure difference inside the branch duct, and obtain the total friction resistance coefficient of the branch duct based on the first real-time pressure difference and the target air volume requirement.

[0050] The purpose of this step is to use the formula for calculating the air volume of the branch ventilation duct to deduce the target air volume required to meet the needs of a single working face. Q req The total frictional resistance coefficient of the branch ventilation duct. An airflow calculation model is established based on the Darcy-Weisbach formula; the expression for the airflow calculation model is: .in, Q Indicates air volume. For pressure difference, f The coefficient of frictional resistance. L The length of the ventilation duct. D Let be the inner diameter of the ventilation duct. Based on the airflow calculation model, the required airflow for a single working face is obtained through deformation. Q req The formula for calculating the total frictional resistance coefficient of the branch ventilation duct is: .in, The total frictional resistance coefficient of the branch ventilation duct. This refers to the real-time pressure difference between the two ends of the branch ventilation duct. D The diameter of the branch ventilation duct. L The length of the branch ventilation duct, This represents the gas density inside the branch ventilation duct.

[0051] Based on the above airflow calculation formula, the real-time pressure difference between the two ends of the branch duct needs to be obtained through in-situ identification. In this embodiment, a pressure sensor continuously collects the pressure difference between the two ends of the branch duct within 5 seconds, and the average value of all pressure difference values ​​is taken as the real-time pressure difference.

[0052] Then, the real-time differential pressure and the diameter of the branch duct obtained in advance through measurement D ,length L and gas density Input the air volume calculation model, output the total friction resistance coefficient of the branch duct. The total frictional resistance coefficient It is the total target frictional resistance coefficient that the branch duct needs to achieve. It comprehensively reflects the resistance characteristics that the duct needs to overcome in order to make the airflow reach the target state (such as the target air volume).

[0053] Step 3: Control the flexible air cavity to apply pulse disturbance to the airflow in the branch duct; obtain the second real-time pressure difference and the first real-time air volume during the pulse disturbance process in the branch duct; obtain the inherent frictional resistance coefficient of the branch duct based on the second real-time pressure difference and the first real-time air volume.

[0054] The purpose of this step is to obtain the target additional frictional resistance coefficient for the annular inflatable rib. f via,target (i.e., the first additional frictional drag coefficient) provides data support. The target additional frictional drag coefficient for the annular inflatable rib liner. f via,target This refers to the additional frictional resistance coefficient that the annular inflatable rib in the branch duct adds to the branch duct through physical structural changes (diameter reduction) under the current adjustment state. The purpose of obtaining the first additional frictional resistance coefficient is to clarify "the magnitude of the resistance brought by the annular inflatable rib that needs to be overcome to achieve the target airflow state (such as the target air volume) in the branch duct," thereby providing data support for adjusting the annular inflatable rib to achieve variable resistance and pressure regulation in multi-face ducts.

[0055] Furthermore, the total frictional resistance coefficient of the branch ventilation duct Based on the inherent drag coefficient of the ventilation duct f fixed The target additional drag coefficient of the annular inflatable rib liner inside the branch ventilation duct. f via,target Composition, that is Among them, the total frictional resistance coefficient It has already been obtained from step 2. f fixed And can be obtained through in-situ identification, .

[0056] Regarding the inherent drag coefficient of the ventilation duct f fixed The method for in-situ identification is as follows: Inherent drag coefficient of the ventilation duct f fixed It refers to the coefficient of friction resistance of a specific branch ventilation duct, which is determined solely by its own physical structure (material, pipe diameter, interface, elbow) without any additional adjustment device intervention.

[0057] To avoid interference with the inherent resistance of the air duct due to the adjustment of the annular inflatable rib, the annular inflatable rib in the branch air duct needs to be adjusted to a "zero additional resistance state" before in-situ identification. This means completely depressurizing the annular inflatable rib, allowing the inner wall of the air duct to return to its natural state without any additional compression causing diameter changes. A flexible air cavity is then used to stimulate a stable transient response in the airflow within the branch air duct. Specifically, the flexible air cavity is controlled to apply pulsed disturbances to the airflow within the branch air duct, causing the volume of the flexible air cavity to periodically change between 90% and 110% of its rated volume (with a period of 0.5 s). This disturbance only changes the airflow velocity in the branch air duct and does not alter the physical structure of the air duct itself.

[0058] It should be noted that: before implementing pulse disturbance, the gas concentration at the working face should be monitored (CH4≤0.5%) to avoid the disturbance causing the diffusion of harmful gases, and at the same time, the pulse amplitude should be ensured to be ≤10% of the rated pressure of the ventilation duct (to prevent damage to the ventilation duct).

[0059] During the pulse disturbance implementation: First, the gas pressure is collected in real time using pressure sensors at both ends of the branch duct (sampling frequency 100Hz, duration 5s), thereby calculating the real-time pressure difference, reflecting the pressure loss of the airflow overcoming the duct resistance; then, the wind speed is collected in real time using an anemometer, and the instantaneous air volume is calculated by multiplying the wind speed by the cross-sectional area of ​​the branch duct; finally, the inherent drag coefficient of the duct is calculated using the Darcy-Weisbach friction drag coefficient formula. f fixed The Darcy-Weisbach friction coefficient formula is: .in, This indicates the real-time pressure difference between the two ends of the branch ventilation duct. D The diameter of the branch ventilation duct. L The length of the branch ventilation duct, The gas density inside the branch ventilation duct. Q S represents the real-time air volume within the branch duct, and S represents the cross-sectional area of ​​the branch duct.

[0060] Step 4: Obtain the first additional friction resistance coefficient of the branch duct based on the total friction resistance coefficient and the inherent friction resistance coefficient.

[0061] Regarding the first additional frictional resistance coefficient f via,target Referring to the explanation of step 3 above, it will not be repeated here.

[0062] Step 5: Control the annular inflatable rib to apply a sweep frequency disturbance to the airflow in the branch duct; obtain the third real-time pressure difference and the second real-time air volume during the sweep frequency disturbance process in the branch duct; obtain the second additional frictional resistance coefficient of the branch duct based on the third real-time pressure difference and the second real-time air volume.

[0063] The first additional frictional resistance coefficient obtained in step 3 is the extra frictional resistance coefficient provided by the annular inflatable rib liner, which is obtained through theoretical calculation. However, under actual operating conditions, the extra frictional resistance coefficient provided by the annular inflatable rib liner (i.e., the second additional frictional resistance coefficient) is... f via,real There is a deviation between the actual frictional resistance coefficient provided by the annular inflatable rib and the theoretically calculated additional frictional resistance coefficient. The purpose of this step is to obtain the additional frictional resistance coefficient provided by the annular inflatable rib under actual working conditions, and thus obtain the deviation of the resistance coefficient.

[0064] The additional frictional resistance coefficient provided by the annular inflatable rib under actual working conditions can also be obtained through in-situ identification, as follows: To obtain the additional frictional resistance coefficient provided by the annular inflatable rib under actual working conditions, it is necessary to control the annular inflatable rib to perform small-amplitude, high-frequency sweep frequency disturbances on the airflow within the grouped ventilation duct (without affecting normal ventilation at the working face), thereby stimulating identifiable fluctuations in the resistance coefficient. The inflation pressure of the annular inflatable rib fluctuates at a frequency of 2Hz within the range of ±0.05MPa of the current set value (e.g., if the current pressure is 0.4MPa, the sweep frequency range is 0.35-0.45MPa), and a short sweep frequency (lasting 1 second) is automatically triggered every 10 seconds.

[0065] During the frequency sweep disturbance process: First, the gas pressure is collected in real time using pressure sensors at both ends of the branch duct (sampling frequency 100Hz, duration 5s), thereby calculating the real-time pressure difference, reflecting the pressure loss of the airflow overcoming the duct's drag coefficient; then, the wind speed is collected in real time using an anemometer, and the instantaneous air volume is calculated by multiplying the wind speed by the cross-sectional area of ​​the branch duct; finally, the Darcy-Weisbach friction drag coefficient formula is used for calculation. See step 3 above for details.

[0066] Step 6: Obtain the drag coefficient deviation between the first additional friction drag coefficient and the second additional friction drag coefficient.

[0067] Δ f i = f via,target - f via,real Among them, Δ f i For drag coefficient deviation Step 7: Adjust the pressure of the ventilation duct at the working face according to the drag coefficient deviation.

[0068] Step 7.1: Establish a mapping table between the first additional frictional resistance coefficient and the inflation pressure of the annular inflatable rib.

[0069] The working principle of the annular inflatable rib is as follows: by changing the inflation pressure, the degree of rib expansion is adjusted, thereby shrinking the equivalent inner diameter of the air duct and changing the wall roughness, ultimately adding controllable frictional resistance to the air duct. The mapping table quantifies this physical adjustment process into a correspondence of "pressure value → resistance coefficient". The first additional frictional resistance coefficient can be quickly obtained by looking up the table, which can also avoid repeatedly executing complex resistance coefficient inversion algorithms on site and reduce the computing power consumption of the edge controller.

[0070] The mapping table can be built in advance through offline experiments. The specific method is as follows: 1. Experimental Platform Setup Ventilation duct simulation: Use ventilation ducts of the same material and diameter as those on site (e.g., 1.2m diameter tunnel branch ventilation duct, made of aging-resistant rubber), and cut a 10m long straight section (without bends or joints to avoid other resistance interference).

[0071] Annular inflatable rib installation simulation: Install the annular inflatable rib to be calibrated (consistent with the model on site) in the middle of the simulated section of the air duct. Connect the rib inflation port to a high-precision air pressure regulating valve (regulation accuracy ±0.02MPa) and a pressure sensor (range 0-1.0MPa, accuracy ±0.005MPa).

[0072] Resistance measurement system simulation: Pressure sensors (range 0-5000Pa, accuracy ±1Pa) and wind speed sensors (range 0-20m / s, accuracy ±0.1m / s) are placed 3m upstream and downstream of the rib to collect pressure loss and air volume, and to invert the additional resistance coefficient.

[0073] 2. Experimental parameter settings Pressure adjustment range: Covers the entire working range of the rib liner, typically 0-0.8MPa (0MPa is full pressure relief, 0.8MPa is the upper limit of pressure resistance), with pressure points set at 0.05MPa intervals (a total of 17 points: 0, 0.05, 0.1, ..., 0.8MPa); Air volume control: The air volume in the duct is stabilized at a common value on site (e.g., 800m³ / min) by a variable frequency fan to ensure that the experimental air volume is consistent with the actual operating air volume and to avoid air volume changes affecting resistance measurement; Data acquisition: After each pressure point has been stabilized for 3 minutes, 3 sets of "upstream and downstream pressure difference and wind speed" data are collected to calculate the average additional resistance.

[0074] 3. Calculation of Additional Drag Coefficient and Construction of Initial Table Calculate the additional drag coefficient for each pressure point using the Darcy-Weisbach formula. Refer to step 3 above.

[0075] 4. Compile the additional drag coefficient data for all pressure points into an initial mapping table, as shown in Table 1 below (data for reference only): Rib liner inflation pressure 0.00 0.05 0.10 0.15 0.20 0.25 0.30 …… 0.80 Additional drag coefficient 0.00 0.005 0.01 0.015 0.02 0.025 0.03 …… 0.08 Table 1 Mapping Relationship Table Step 7.2: When the drag coefficient deviation is greater than zero, a first control command is generated based on the target inflation pressure. The first control command controls the solenoid valve to inflate the annular inflatable rib to the target pressure. When the drag coefficient deviation is less than zero, a second control command is generated based on the target inflation pressure. The second control command controls the solenoid valve to depressurize the annular inflatable rib to the target pressure.

[0076] When the drag coefficient deviation is greater than zero, the first additional friction drag coefficient of the annular inflatable rib needs to be increased. As calculated... fvia,target =0.03, the corresponding inflation pressure is found to be 0.3MPa according to the table, so a "inflate to 0.3MPa" command is sent directly to the rib solenoid valve. Similarly, when the resistance coefficient deviation is less than zero, the first additional friction resistance coefficient of the annular inflatable rib needs to be reduced.

[0077] In summary, the multi-face ventilation duct variable resistance pressure regulation method provided in this embodiment achieves direct adjustment of the internal resistance of the ventilation duct through a full-process technical architecture of "environmental parameter perception - dynamic calculation of target air volume demand - dual-component coordinated adjustment (flexible air cavity + annular inflatable rib) - in-situ resistance coefficient identification - resistance coefficient deviation correction", thereby reducing the imbalance of the internal environment of the ventilation duct caused by cross-face airflow interference and transient disturbances of the external environment.

[0078] Example 2: Corresponding to Example 1, this example provides a multi-face ventilation duct variable resistance pressure regulation system, including: The environmental parameter acquisition module is used to collect the first environmental parameters inside the branch ventilation duct and the second environmental parameters at the working face; the branch ventilation duct is equipped with a flexible air cavity and an annular inflatable rib liner; The air volume demand acquisition module is used to acquire the target air volume demand at the working face based on the first environmental parameter and the second environmental parameter. The first differential pressure acquisition module is used to acquire the first real-time differential pressure inside the branch ventilation duct; The first resistance coefficient acquisition module is used to obtain the total friction resistance coefficient of the branch duct based on the first real-time pressure difference and the target required air volume. The first control module is used to control the flexible air cavity to apply pulse disturbances to the airflow in the branch duct. The second differential pressure acquisition module is used to acquire the second real-time differential pressure during the pulse disturbance process in the branch duct. The first air volume acquisition module is used to acquire the first real-time air volume during the pulse disturbance process in the branch air duct. The second resistance coefficient acquisition module is used to acquire the inherent friction resistance coefficient of the branch duct based on the second real-time pressure difference and the first real-time air volume. The third resistance coefficient acquisition module is used to obtain the first additional friction resistance coefficient of the branch duct based on the total friction resistance coefficient and the inherent friction resistance coefficient. The second control module is used to control the annular inflatable rib to apply a sweep frequency disturbance to the airflow in the branch duct. The third differential pressure acquisition module is used to acquire the third real-time differential pressure during the frequency sweep disturbance process inside the branch duct; The second air volume acquisition module is used to acquire the second real-time air volume during the frequency sweeping disturbance process in the branch air duct. The fourth resistance coefficient acquisition module is used to obtain the second additional friction resistance coefficient of the branch duct based on the third real-time pressure difference and the second real-time air volume. The drag coefficient deviation acquisition module is used to acquire the drag coefficient deviation between the first additional friction drag coefficient and the second additional friction drag coefficient. The variable resistance voltage regulation module is used to adjust the resistance and voltage of the ventilation duct at the working face according to the deviation of the resistance coefficient.

[0079] Furthermore, the required air volume acquisition module includes: The first required air volume acquisition unit is used to acquire the first required air volume based on the personnel safety factor, the number of personnel, and the minimum required air volume per person; The second air volume acquisition unit is used to acquire the second air volume based on the real-time number of internal combustion equipment, the heat dissipation coefficient of internal combustion equipment, and the rated power of internal combustion equipment. The third required air volume acquisition unit is used to acquire the third required air volume based on the blasting safety redundancy, carbon monoxide mass, permissible carbon monoxide concentration and purification time limit; The fourth air volume acquisition unit is used to acquire the fourth air volume based on the methane emission rate and the permissible methane concentration. The fifth required air volume acquisition unit is used to acquire the fifth required air volume based on the dust concentration and the effective volume of the working face; The sixth air volume acquisition unit is used to acquire the maximum value between the first air volume, the second air volume, the third air volume, the fourth air volume, the fifth air volume and the standard minimum air volume, to obtain the actual air volume; The seventh air volume acquisition unit is used to correct the actual air volume demand using the altitude correction coefficient and the tunnel band coefficient to obtain the target air volume demand.

[0080] Furthermore, the multi-face ventilation duct variable resistance pressure regulating system also includes: The first data preprocessing module is used to perform Kalman filtering on the first environmental parameters and the second environmental parameters. The second data preprocessing module is used to perform 3σ outlier removal on the first and second environmental parameters after Kalman filtering.

[0081] Furthermore, the multi-face ventilation duct variable resistance pressure regulating system also includes: The mapping table creation module is used to create a mapping table between the first additional frictional resistance coefficient and the inflation pressure of the annular inflatable rib.

[0082] Furthermore, the variable resistance voltage regulation module includes: The mapping relationship table lookup unit is used to look up the mapping relationship table based on the first additional frictional resistance coefficient to obtain the target pressure; The first control command generation unit is used to generate a first control command based on the target inflation pressure when the drag coefficient deviation is greater than zero; the first control command is used to control the solenoid valve to inflate the annular inflatable rib to the target pressure. The second control command generation unit is used to generate a second control command based on the target inflation pressure when the drag coefficient deviation is less than zero; the second control command is used to control the solenoid valve to depressurize the annular inflatable rib to the target pressure.

[0083] It should be noted that in the multi-face ventilation duct variable resistance pressure regulation system provided in this embodiment, the internal working principle and operation logic of each functional module and functional unit can be referred to the corresponding explanation in Embodiment 1, and will not be repeated in this embodiment.

[0084] Example 3: Based on the method provided in Example 1 and the system provided in Example 2, this example provides a computer device that executes the method described in Example 1 or any other method that may involve the method described in Example 1. The device includes a memory, a processor, and a transceiver connected in sequence. The memory stores a computer program, the transceiver sends and receives messages, and the processor reads the computer program and executes the method described in Example 1 or any other method that may involve the method described in Example 1. Specifically, the memory may include, but is not limited to, random-access memory (RAM), read-only memory (ROM), flash memory, first-in-first-out (FIFO) memory, and / or last-in-first-out (FILO) memory, etc.; the processor may include, but is not limited to, a microprocessor of the STM32F105 series. Furthermore, the computer device may also include, but is not limited to, a power module, a display screen, and other necessary components.

[0085] The working process, working details and technical effects of the aforementioned computer device provided in this embodiment can be found in the method described in Embodiment 1 or any method that may involve the method described in Embodiment 1, and will not be repeated here.

[0086] Example 4: This example provides a computer-readable storage medium that stores instructions that include the method described in Example 1 or any other method that may involve the method described in Example 1. Specifically, the computer-readable storage medium stores instructions that, when executed on a computer, perform the method described in Example 1 or any other method that may involve the method described in Example 1. The computer-readable storage medium refers to a data storage medium, which may include, but is not limited to, floppy disks, optical disks, hard disks, flash memory, USB flash drives, and / or Memory Sticks. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.

[0087] The working process, working details and technical effects of the aforementioned computer-readable storage medium provided in this embodiment can be found in the method described in Embodiment 1 or any method that may be related to Embodiment 1, and will not be repeated here.

[0088] Example 5: This example provides a computer program product containing instructions that, when executed on a computer, cause the computer to perform the method described in Example 1 or any method that may involve the method described in Example 1. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device.

[0089] It should be understood that the terms "system," "device," "unit," and / or "module" as used in this specification are a method of distinguishing different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0090] As indicated in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0091] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0092] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the disclosed technical content. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

Claims

1. A method for regulating pressure in a multi-face ventilation duct using variable resistance, characterized in that, Includes the following steps: The first environmental parameter inside the branch ventilation duct and the second environmental parameter at the working face are collected; the target air volume at the working face is obtained based on the first and second environmental parameters; the branch ventilation duct is equipped with a flexible air cavity and annular inflatable ribs. Obtain the first real-time pressure difference within the branch duct; obtain the total frictional resistance coefficient of the branch duct based on the first real-time pressure difference and the target air volume requirement; The flexible air cavity is controlled to apply pulse disturbances to the airflow within the branch duct; The second real-time pressure difference and the first real-time air volume are obtained during the pulse disturbance process in the branch duct; the inherent frictional resistance coefficient of the branch duct is obtained based on the second real-time pressure difference and the first real-time air volume. The first additional friction resistance coefficient of the branch duct is obtained based on the total friction resistance coefficient and the inherent friction resistance coefficient. The annular inflatable rib is controlled to apply a frequency sweeping disturbance to the airflow in the branch duct; the third real-time pressure difference and the second real-time air volume are obtained during the frequency sweeping disturbance process in the branch duct; the second additional frictional resistance coefficient of the branch duct is obtained based on the third real-time pressure difference and the second real-time air volume. Obtain the drag coefficient deviation between the first additional friction drag coefficient and the second additional friction drag coefficient; The pressure of the ventilation duct at the working face is adjusted by varying the drag coefficient based on the deviation.

2. The method for variable resistance pressure regulation of a multi-face ventilation duct according to claim 1, characterized in that, Before collecting the first environmental parameters inside the branch ventilation duct and the second environmental parameters at the working face, the following steps are also included: Install carbon monoxide sensors, methane sensors, multiple wind speed sensors, multiple gas pressure sensors, and multiple dust sensors on the inner wall of the branch ventilation duct. Install a UWB positioning module and an internal combustion equipment condition data acquisition device near the working face; Annular inflatable ribs are installed at the bifurcation point between the branch duct and the main duct, and at the end of the branch duct. A flexible air cavity is connected in parallel on the branch ventilation duct.

3. A method for regulating the resistance and pressure of a multi-face ventilation duct according to claim 1 or 2, characterized in that, The primary environmental parameters include: carbon monoxide mass, dust concentration, methane emission, and dust concentration; The second environmental parameter includes: real-time number of personnel, real-time number of internal combustion equipment, and power of internal combustion equipment; The target air volume at the working face is obtained based on the first environmental parameter and the second environmental parameter, including the following steps: The first required air volume is obtained based on the personnel safety factor, the number of personnel, and the minimum air volume required per person. The second required air volume is obtained based on the real-time number of internal combustion equipment, the heat dissipation coefficient of internal combustion equipment, and the rated power of internal combustion equipment. The third required air volume is obtained based on the blasting safety redundancy, carbon monoxide mass, permissible carbon monoxide concentration, and purification time limit; The fourth required air volume is obtained based on the methane emission rate and the permissible methane concentration; The fifth required air volume is obtained based on the dust concentration and the effective volume of the working face; Obtain the maximum value among the first required air volume, the second required air volume, the third required air volume, the fourth required air volume, the fifth required air volume and the standard minimum required air volume to obtain the actual required air volume; The actual air demand is corrected using an altitude correction factor and a tunnel band factor to obtain the target air demand.

4. A method for regulating the resistance and pressure of a multi-face ventilation duct according to claim 1 or 2, characterized in that, After collecting the first environmental parameters inside the branch ventilation duct and the second environmental parameters at the working face, the following steps are also included: Kalman filtering is applied to the first and second environmental parameters; The first and second environmental parameters after Kalman filtering are subjected to 3σ outlier removal.

5. A method for regulating the resistance and pressure of a multi-face ventilation duct according to claim 1 or 2, characterized in that, The method for controlling the flexible air cavity to apply pulse disturbance to the airflow in the branch duct is to control the volume of the flexible air cavity to change periodically between 90% and 110% of the rated volume. The method for controlling the frequency sweeping disturbance applied to the airflow in the branch duct by the annular inflatable rib is as follows: control the inflation pressure of the annular inflatable rib to vary according to a preset frequency within the range of ±0.05 MPa of the preset initial pressure.

6. A method for regulating the resistance and pressure of a multi-face ventilation duct according to claim 1 or 2, characterized in that, Before adjusting the pressure of the face ventilation duct according to the drag coefficient deviation, the following steps are also included: establishing a mapping table between the first additional friction drag coefficient and the inflation pressure of the annular inflatable rib.

7. A method for regulating the resistance and pressure of a multi-face ventilation duct according to claim 6, characterized in that, Adjusting the pressure of the ventilation duct at the working face based on the drag coefficient deviation includes the following steps: The target pressure is obtained by consulting the mapping table based on the first additional friction resistance coefficient; When the drag coefficient deviation is greater than zero, a first control command is generated based on the target inflation pressure; the first control command is used to control the solenoid valve to inflate the annular inflatable rib to the target pressure. When the drag coefficient deviation is less than zero, a second control command is generated based on the target inflation pressure; the second control command is used to control the solenoid valve to depressurize the annular inflatable rib to the target pressure.

8. A variable resistance pressure regulating system for a multi-face ventilation duct, characterized in that, include: The environmental parameter acquisition module is used to collect the first environmental parameters inside the branch ventilation duct and the second environmental parameters at the working face; The branch ventilation duct is equipped with a flexible air cavity and an annular inflatable rib; The air volume demand acquisition module is used to acquire the target air volume demand at the working face based on the first environmental parameter and the second environmental parameter. The first differential pressure acquisition module is used to acquire the first real-time differential pressure inside the branch ventilation duct; The first resistance coefficient acquisition module is used to obtain the total friction resistance coefficient of the branch duct based on the first real-time pressure difference and the target required air volume. The first control module is used to control the flexible air cavity to apply pulse disturbances to the airflow in the branch duct. The second differential pressure acquisition module is used to acquire the second real-time differential pressure during the pulse disturbance process in the branch duct. The first air volume acquisition module is used to acquire the first real-time air volume during the pulse disturbance process in the branch air duct. The second resistance coefficient acquisition module is used to acquire the inherent friction resistance coefficient of the branch duct based on the second real-time pressure difference and the first real-time air volume. The third resistance coefficient acquisition module is used to obtain the first additional friction resistance coefficient of the branch duct based on the total friction resistance coefficient and the inherent friction resistance coefficient. The second control module is used to control the annular inflatable rib to apply a sweep frequency disturbance to the airflow in the branch duct. The third differential pressure acquisition module is used to acquire the third real-time differential pressure during the frequency sweep disturbance process inside the branch duct; The second air volume acquisition module is used to acquire the second real-time air volume during the frequency sweeping disturbance process in the branch air duct. The fourth resistance coefficient acquisition module is used to obtain the second additional friction resistance coefficient of the branch duct based on the third real-time pressure difference and the second real-time air volume. The drag coefficient deviation acquisition module is used to acquire the drag coefficient deviation between the first additional friction drag coefficient and the second additional friction drag coefficient. The variable resistance voltage regulation module is used to adjust the resistance and voltage of the ventilation duct at the working face according to the deviation of the resistance coefficient.

9. A multi-face ventilation duct variable resistance pressure regulation system according to claim 8, characterized in that, The air volume acquisition module includes: The first required air volume acquisition unit is used to acquire the first required air volume based on the personnel safety factor, the number of personnel, and the minimum required air volume per person; The second air volume acquisition unit is used to acquire the second air volume based on the real-time number of internal combustion equipment, the heat dissipation coefficient of internal combustion equipment, and the rated power of internal combustion equipment. The third required air volume acquisition unit is used to acquire the third required air volume based on the blasting safety redundancy, carbon monoxide mass, permissible carbon monoxide concentration and purification time limit; The fourth air volume acquisition unit is used to acquire the fourth air volume based on the methane emission rate and the permissible methane concentration. The fifth required air volume acquisition unit is used to acquire the fifth required air volume based on the dust concentration and the effective volume of the working face; The sixth air volume acquisition unit is used to acquire the maximum value between the first air volume, the second air volume, the third air volume, the fourth air volume, the fifth air volume and the standard minimum air volume, to obtain the actual air volume; The seventh air volume acquisition unit is used to correct the actual air volume demand using the altitude correction coefficient and the tunnel band coefficient to obtain the target air volume demand.

10. A multi-face ventilation duct variable resistance pressure regulation system according to claim 8 or 9, characterized in that, Also includes: The first data preprocessing module is used to perform Kalman filtering on the first environmental parameters and the second environmental parameters. The second data preprocessing module is used to perform 3σ outlier removal on the first and second environmental parameters after Kalman filtering.

11. A multi-face ventilation duct variable resistance pressure regulation system according to claim 8 or 9, characterized in that, Also includes: The mapping table creation module is used to create a mapping table between the first additional frictional resistance coefficient and the inflation pressure of the annular inflatable rib.

12. A multi-face ventilation duct variable resistance pressure regulation system according to claim 11, characterized in that, The variable resistance voltage regulation module includes: The mapping relationship table lookup unit is used to look up the mapping relationship table based on the first additional frictional resistance coefficient to obtain the target pressure; The first control command generation unit is used to generate a first control command based on the target inflation pressure when the drag coefficient deviation is greater than zero; the first control command is used to control the solenoid valve to inflate the annular inflatable rib to the target pressure. The second control command generation unit is used to generate a second control command based on the target inflation pressure when the drag coefficient deviation is less than zero; the second control command is used to control the solenoid valve to depressurize the annular inflatable rib to the target pressure.

13. A computer device comprising a memory, a processor, and a transceiver sequentially and communicatively connected, wherein, The memory is used to store computer programs, the transceiver is used to send and receive data, and the processor is used to read the computer programs and execute the variable resistance pressure regulation method for multi-face ventilation ducts as described in any one of claims 1-7.

14. A computer-readable storage medium storing instructions that, when executed on a computer, perform a multi-face wind tunnel variable resistance pressure regulation method as described in any one of claims 1-7.

15. A computer program product containing instructions that, when executed on a computer, cause the computer to perform a multi-face ventilation duct variable resistance pressure regulation method as described in any one of claims 1-7.

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