A structure for generating a fog curtain in a roadway and a control method

Abstract

The application discloses a kind of generation structure and control method of roadway fog screen, belong to roadway fire-fighting technical field, to solve the problem of low efficiency in prior art using spray to block roadway fire smoke and fire.Therein, the generation structure and control method of roadway fog screen, with environmental factors as the main consideration of control nozzle, make the formation of fog screen more fit the dynamic environment in each roadway, improve the rationality of water resource allocation, improve the efficiency of fire blocking;With escape as the ultimate purpose orientation, the escape risk score obtained according to the environmental signal and the wind path relationship are used to determine the sealing partition type of each roadway, so that the development of safety strategy can be highly matched with the physical law of roadway fire spread and the demand of personnel escape, further improve the efficiency and rationality of fog screen blocking fire.

Description

Technical Field

[0001] This invention relates to the field of tunnel fire protection technology, specifically to a structure and control method for generating fog curtains in tunnels. Background Technology

[0002] External fires in mines are characterized by their suddenness, rapid development, significant smoke hazard, and short response window. Once a fire occurs, high-temperature smoke will spread rapidly along the roadways under the influence of the ventilation system, threatening the safety of underground personnel evacuation and emergency response.

[0003] In existing technologies, when a mine roadway fire develops to a certain scale, a solid, airtight wall is often constructed to seal the fire source area, suffocating the fire by restricting oxygen supply. While this method can suppress the fire, it suffers from problems such as difficulties in material transportation, long construction periods, the need for personnel to enter dangerous areas, difficulty in adjusting the sealed position, and significant disturbance to subsequent rescue channels. Fine water mist has the advantages of small droplet size, large specific surface area, rapid evaporation and heat absorption, good cooling and insulation effects, and low water consumption. However, due to the influence of the environment inside the mine roadway, water spray is prone to deviation, penetration, entrainment, and local voids, making it difficult for a single-position fixed spray to stably block smoke.

[0004] Therefore, in the existing technology, using spray to block smoke and fire in roadway fires is inefficient. Summary of the Invention

[0005] The purpose of this application is to overcome the shortcomings of the prior art and provide a structure and control method for generating fog curtains in roadways that efficiently blocks smoke and fire in roadway fires.

[0006] To achieve the above objectives, this application adopts the following technical solution: In a first aspect, this application provides a method for controlling fog in a tunnel, comprising: acquiring environmental signals from various sensors and obtaining an escape risk score based on the environmental signals.

[0007] In response to the escape risk score reaching the disaster threshold, different types of blockade zones are selected from each alleyway based on the wind path relationship and the escape risk score.

[0008] Obtain the security policies corresponding to different types of blocking zones, construct an objective function based on the security policies, optimize the control terms using the objective function, and use the optimized control terms to control the nozzles to form a fog screen.

[0009] Furthermore, the escape risk score is obtained by calculation using the following formula: In the formula, For the counting sequence number, For the first Escape risk score for each sensor node , , , , , and These are non-negative weights. For the first The temperature of each sensor node, For the first The temperature rise rate of each sensor node, For the first Carbon monoxide concentration at each sensor node For the first The amount of oxygen decrease at each sensor node. For the first The decrease in flue gas permeability at each sensor node For the first Confidence of flame images from individual sensor nodes For the first Wind speed disturbance at each sensor node.

[0010] Furthermore, the step of selecting different types of blocking zones from various alleyways based on wind path relationships and escape risk scores includes: obtaining alleyway maps and wind direction, and abstracting the alleyway map into a directed graph based on the wind direction.

[0011] The edge weights of each alleyway in the directed graph are determined based on distance weight, wind speed weight, and the escape risk score.

[0012] A roadway whose escape risk score exceeds the fire source threshold and whose duration reaches the first time threshold is defined as a fire source section roadway.

[0013] Based on the location of the fire source section in the directed graph and the edge weight of each section in the directed graph, different types of blocking zones are selected from each section.

[0014] Furthermore, it also includes: setting the control cycle.

[0015] Different types of blockade zones are reselected based on the escape risk score for each control cycle; the escape risk score for each control cycle is calculated using the following formula: In the formula, For the counting sequence number, For the first The period and the th period Escape risk score for each sensor node For the first The period and the th period The temperature of each sensor node, For the first The period and the th period The temperature rise rate of each sensor node, For the first The period and the th period Carbon monoxide concentration at each sensor node For the first The period and the th period The amount of oxygen decrease at each sensor node. For the first The period and the th period The decrease in flue gas permeability at each sensor node For the first The period and the th period Confidence of flame images from individual sensor nodes For the first The period and the th period Wind speed disturbance at each sensor node.

[0016] The first time threshold is two control cycles.

[0017] The method for obtaining the duration of the control cycle is as follows: obtain the initial cycle duration.

[0018] The initial cycle duration was verified using the sensor refresh rate, the zone valve action time, and the pump group stabilization time.

[0019] The initial cycle duration that passes the verification is used as the duration of the control cycle.

[0020] Furthermore, the step of constructing an objective function based on the safety strategy, optimizing the control terms using the objective function, and controlling the nozzles to form a fog screen using the optimized control terms includes: the objective function is as follows: In the formula, For the first The objective function for each period, , , , and These are the safety weights, The smoke permeability or visibility on the downwind side exceeds the limit. This refers to the deviation of oxygen concentration from the safe threshold for personnel. If the temperature or rate of temperature rise on the downwind side exceeds the limit, Penalty based on water consumption or drainage pressure per unit time. Penalties are imposed for risks related to personnel passage, equipment energization, and water accumulation; the safety weights are obtained through safety policies.

[0021] The optimization objective is to minimize the value of the objective function.

[0022] The constraints include: upper limit of pump unit pressure, range of zone valve opening, range of nozzle angle, drainage capacity, power supply status, and personnel evacuation status.

[0023] The control items include: valve opening degree, spray pressure, number of nozzles starting and stopping, spray angle, and number of fog curtain columns.

[0024] Based on the optimization objective, the constraints, and the objective function, the optimized control term for the current control cycle is obtained, and the optimized control term for the current control cycle is used to control the nozzle to form a fog curtain.

[0025] Furthermore, the method of using optimized control terms to control the nozzle to form a fog curtain also includes: obtaining feedback error based on the downwind smoke permeability, oxygen concentration, temperature, and the risk of reignition in the flame image.

[0026] Based on the feedback error, the optimized control term is fine-tuned using PID control in the next control cycle to obtain the finely tuned PID control term; in the next control cycle, the finely tuned PID control term is used to control the nozzle to form a fog curtain.

[0027] The control term after PID fine-tuning is obtained by calculation using the following formula: In the formula, For the first The control term after PID fine-tuning for each control cycle For a limiting function subject to constraints, For the first Control items for each control cycle, For proportional gain, For integral gain, For differential gain, For the first Feedback error within each control cycle For the counting sequence number, For the first The last moment of each control cycle, From the start of the nozzle until the... The sum of feedback errors at all times within the last moment of each control cycle. For the first At that moment, For the first Feedback error within each control cycle.

[0028] Furthermore, the method of using optimized control terms to control the nozzle to form a fog curtain also includes: obtaining feedback error based on the downwind smoke permeability, oxygen concentration, temperature, and the risk of reignition in the flame image.

[0029] In response to the feedback error exceeding the error threshold, the nozzle is progressively adjusted according to a priority sequence of actions, which are: fine-tuning the nozzle pressure, correcting the nozzle angle, increasing the number of fog columns, increasing the number of nozzles, and activating the fog curtain in adjacent zones.

[0030] In response to feedback errors exceeding an error threshold for multiple consecutive control cycles, the water consumption of the nozzle is reduced.

[0031] Secondly, this application also provides a structure for generating fog in a tunnel, comprising: a controller for executing the control method for fog in a tunnel as described in any one of the first aspects.

[0032] The sensor, which is electrically connected to the controller, is used to acquire environmental signals in each tunnel.

[0033] The nozzle, which is electrically connected to the controller, is used to form a fog curtain in the tunnel.

[0034] Furthermore, it also includes: a nozzle array consisting of the nozzle arrangement is distributed at the top, sides and bottom of the tunnel.

[0035] The nozzle spacing and number of nozzles in the nozzle column located at the top of the tunnel are obtained based on the effective mist cone diameter of the nozzles. The nozzle spacing and number of nozzles in the nozzle column located at the top of the tunnel are obtained by the following formula: In the formula, This refers to the number of nozzles located in the nozzle row at the top of the tunnel. The width of the alleyway, The nozzle spacing is the distance between the nozzles in the nozzle row located at the top of the tunnel. For the effective fog cone diameter, The effective distance from the nozzle to the target coverage area. For the spray angle, This is the longitudinal airflow reduction factor.

[0036] The nozzle spacing and number of nozzles in the nozzle row located on the side of the tunnel are obtained based on the effective mist cone diameter of the nozzles. The nozzle spacing and number of nozzles in the nozzle row located on the side of the tunnel are obtained by the following formula: In the formula, This refers to the number of sprinklers located in the sprinkler row on the side of the tunnel. The height of the tunnel, This refers to the nozzle spacing of the nozzle row located on the side of the tunnel.

[0037] Furthermore, it also includes: in response to the wind speed in the tunnel not exceeding 1.5 m / s and the tunnel slope not exceeding 5°, a row of nozzles is installed at the top, side and bottom of the tunnel.

[0038] In response to a wind speed in the tunnel greater than 1.5 m / s and not exceeding 3.0 m / s, or a tunnel slope greater than 5° and not exceeding 10°, two rows of nozzles are installed at the top, side and bottom of the tunnel.

[0039] In response to a wind speed greater than 3.0 m / s in the tunnel or a slope greater than 10° in the tunnel, three rows of nozzles are installed at the top, sides and bottom of the tunnel.

[0040] The distance between the diameters of adjacent nozzle rows shall not be less than 1m and not more than 3m.

[0041] Compared with the prior art, the beneficial effects achieved by this application are as follows: The fog curtain generation structure and control method in the tunnel provided in this embodiment takes environmental factors as the main consideration for controlling the nozzles, making the formation of the fog curtain more in line with the dynamic environment in each tunnel, improving the rationality of water resource allocation, and improving the efficiency of fire blocking; with escape as the ultimate goal, the type of blocking zone for each tunnel is determined by the escape risk score and wind path relationship obtained from the environmental signal, so that the formulation of safety strategy can be highly matched with the physical law of fire propagation in the tunnel and the needs of personnel escape, further improving the efficiency and rationality of fog curtain fire blocking. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a flowchart of the steps of the fog control method in the tunnel provided in the embodiments of this application.

[0044] Figure 2 This is a signal structure diagram of the fog curtain generation structure in the tunnel provided in the embodiments of this application.

[0045] Figure 3 This is a schematic diagram of the zoned fine water mist curtain arrangement in the mine ventilation network.

[0046] In the diagram: 1. Controller; 2. Sensor; 3. Nozzle; 100. Ignition source; 101. Intake airway; 102. Return airway; 103. Connecting airway; 104. Mining face; 105. Working face passage; 110. Sensor node; 120. Zone control valve; 130. Fine water mist curtain. Detailed Implementation

[0047] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations thereof. In the absence of conflict, the embodiments and technical features in the embodiments can be combined with each other.

[0048] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0049] Example 1

[0050] Figure 1 This is a flowchart illustrating a method for controlling fog in a tunnel according to Embodiment 1 of the present invention. This flowchart merely shows the logical sequence of the method described in this embodiment. Provided there are no conflicts, different methods may be used in other possible embodiments of the present invention. Figure 1 Complete the steps shown or described in the order indicated.

[0051] See Figure 1 The method of this implementation specifically includes the following steps: environmental factors in the tunnel are the main factors that reduce the efficiency of spray blocking fire flames and dense smoke. Therefore, the environmental signals of each sensor 2 are acquired, and the escape risk score of each tunnel is obtained based on the environmental signals.

[0052] In response to the escape risk score reaching the disaster threshold, it is considered that a fire has occurred in the alley or that the fire has spread into the alley. In addition to the location of the fire source section of the alley, the direction of wind flow is one of the main factors determining the spread of fire. Therefore, in this embodiment, different types of blocking zones are selected from each alley according to the wind path relationship and the escape risk score. The location of each zone is different, and the dynamic safety strategy for controlling the nozzles 3 to form a fog curtain is also different.

[0053] Obtain the security policies corresponding to different types of blocking zones, construct an objective function based on the security policies, optimize the control terms using the objective function, and use the optimized control terms to control the nozzle 3 to form a fog curtain.

[0054] It is worth noting that as the fire continues to evolve, the escape risk score of the same alleyway will change, the type of blockade zone will change, and the safety strategy will also change.

[0055] The fog control method in the tunnels provided in this embodiment takes environmental factors as the main consideration for controlling the nozzles 3, making the formation of the fog more in line with the dynamic environment in each tunnel, improving the rationality of water resource allocation, and improving the efficiency of fire blocking; with escape as the ultimate goal, the method determines the blocking zone type of each tunnel based on the escape risk score and wind path relationship obtained from environmental signals, so that the formulation of safety strategies can be highly matched with the physical laws of fire propagation in tunnels and the needs of personnel escape, further improving the efficiency and rationality of fog blocking fires.

[0056] Example 2

[0057] This embodiment provides a method for controlling fog in a tunnel. This embodiment is an optimization based on Embodiment 1 to improve the technical effect and refine the technical solution. For details not described in this embodiment, please refer to Embodiment 1.

[0058] As one embodiment, the escape risk score is calculated using the following formula: In the formula, For the counting sequence number, For the first Escape risk score for each sensor node , , , , , and These are non-negative weights. For the first The temperature of each sensor node, For the first The temperature rise rate of each sensor node, For the first Carbon monoxide concentration at each sensor node For the first The amount of oxygen decrease at each sensor node. For the first The decrease in flue gas permeability at each sensor node For the first Confidence of flame images from individual sensor nodes For the first The wind speed disturbance of each sensor node; as one embodiment, each variable marked with * is a normalized value.

[0059] In this embodiment, the calculation of the escape risk score not only takes into account temperature, temperature rise rate and wind speed disturbance, but also the factors of oxygen, harmful smoke and carbon monoxide that are crucial for personnel escape. Furthermore, it takes into account that some sensors 2 may be damaged at high temperatures, and introduces flame image confidence to evaluate escape risk. The influence of the above factors is controlled by non-negative weights, making the formulation of the blockade zone type more scientific.

[0060] As one embodiment, , , , , , and The sum of these seven non-negative weights is 1. The initial non-negative weights can be set according to temperature rise, carbon monoxide to oxygen ratio, flue gas transmittance and flame image priority, and subsequently calibrated by on-site alarm records. The disaster threshold is determined by adding a safety margin to the normal ventilation baseline or by the current "Coal Mine Safety Regulations" and the alarm limit of the mine safety monitoring system.

[0061] As one embodiment, the step of selecting different types of blocking zones from various alleyways based on wind path relationships and escape risk scores includes: obtaining alleyway maps and wind direction, and abstracting the alleyway map into a directed graph based on the wind direction; the direction of each vector in the directed graph represents the wind direction.

[0062] The weights for each vector in the directed graph are determined based on distance weights, wind speed weights, and the escape risk score. In other words, each alleyway is assigned an edge weight that combines environmental factors confined to a single alleyway with topological features that extend beyond a single alleyway and encompass all alleyways.

[0063] A roadway whose escape risk score exceeds the fire source threshold and whose duration reaches the first time threshold is defined as a fire source section roadway.

[0064] Based on the location of the fire source section in the directed graph and the edge weight of each section in the directed graph, different types of blocking zones are selected from each section; that is, after knowing the fire source section, the section that needs to be blocked by fog is selected according to the wind direction and personnel escape factors. Different sections play different roles in fog blocking, and the different types of blocking zones also determine different safety strategies.

[0065] The distance weights can be determined based on the distance of each alleyway from the escape exit and the fire source section.

[0066] Because fires within roadways are dynamic, for example, intake airways, belt conveyor roadways, mining faces, and connecting roadways typically contain flammable or heat-damaged materials such as conveyor belts, cables, electromechanical equipment, and support materials. When these items are ignited, new fire source sections are created in the roadways, thus changing the type of sealing zone for each roadway. In this embodiment, a continuous control cycle is used for rolling fire sealing, and each nozzle 3 is periodically controlled in a rolling manner.

[0067] As one embodiment, a control cycle is set; the duration of the control cycle is generally between 1 and 10 seconds.

[0068] Different types of blockade zones are reselected based on the escape risk score for each control cycle; the escape risk score for each control cycle is calculated using the following formula: In the formula, For the counting sequence number, For the first The period and the th period Escape risk score for each sensor node For the first The period and the th period The temperature of each sensor node, For the first The period and the th period The temperature rise rate of each sensor node, For the first The period and the th period Carbon monoxide concentration at each sensor node For the first The period and the th period The amount of oxygen decrease at each sensor node. For the first The period and the th period The decrease in flue gas permeability at each sensor node For the first The period and the th period Confidence of flame images from individual sensor nodes For the first The period and the th period Wind speed disturbance at each sensor node.

[0069] The first time threshold is two control cycles.

[0070] The method for obtaining the duration of the control cycle is as follows: obtain the initial cycle duration.

[0071] The initial cycle duration was verified using the sensor refresh rate, the zone valve action time, and the pump group stabilization time.

[0072] The initial cycle duration that passes the verification is used as the duration of the control cycle.

[0073] The purpose of time verification is to ensure that theoretical calculations match and synchronize with the actual responses of each hardware component.

[0074] As one embodiment, the step of constructing an objective function based on the safety strategy, and using the objective function to optimize control terms, generally includes the opening degree of each zone valve, spray pressure, number of nozzles starting and stopping, spray angle, and number of fog curtain columns. The optimized control terms are used to control the nozzles 3 to form a fog curtain, including: the objective function is as follows: In the formula, For the first The objective function for each period, , , , and These are the safety weights, The smoke permeability or visibility on the downwind side exceeds the limit. This refers to the deviation of oxygen concentration from the safe threshold for personnel. If the temperature or rate of temperature rise on the downwind side exceeds the limit, Penalty based on water consumption or drainage pressure per unit time. Penalties are imposed for risks related to personnel passage, equipment energization, and water accumulation; the safety weights are obtained through a safety strategy; in this embodiment, the objective function is consistent with the design of the escape risk score, and physical factors affecting personnel escape, such as temperature, oxygen, harmful gases, and visibility, are also considered; since the water storage capacity of the fire protection system in the tunnel is difficult to replenish in a short time, this embodiment also introduces penalties for water consumption or drainage pressure per unit time into the objective function. To avoid wasting water resources, and because prolonged and high-flow fog can cause water accumulation in some alleyways, affecting personnel passage or causing equipment malfunctions, this embodiment also incorporates penalties for personnel passage, equipment energization, and water accumulation risks into the objective function. To avoid this phenomenon from occurring.

[0075] The optimization objective is to minimize the value of the objective function.

[0076] The constraints include: upper limit of pump unit pressure, range of zone valve opening, range of nozzle angle, drainage capacity, power supply status, and personnel evacuation status.

[0077] The control items include: valve opening degree, spray pressure, number of nozzles starting and stopping, spray angle, and number of fog curtain columns.

[0078] Based on the optimization objective, the constraints, and the objective function, the optimized control term for the current control cycle is obtained, and the optimized control term for the current control cycle is used to control the nozzle 3 to form a fog curtain.

[0079] The pump set refers to the pump set that controls the water source and water pressure of the nozzle 3, and the opening degree of the zone valve refers to the opening degree that controls the water supply to different blocking zones. The number of fog curtain columns is determined by the number of nozzle columns, and a single nozzle column consists of linearly distributed nozzles 3.

[0080] As one embodiment, the method of using optimized control terms to control the nozzle 3 to form a fog curtain further includes: obtaining feedback error based on the downwind smoke permeability, oxygen concentration, temperature, and flame image reignition risk.

[0081] Based on the feedback error, the optimized control term is fine-tuned using PID control in the next control cycle to obtain the fine-tuned PID control term; in the next control cycle, the fine-tuned PID control term is used to control the nozzle 3 to form a fog curtain.

[0082] The control term after PID fine-tuning is obtained by calculation using the following formula: In the formula, For the first The control term after PID fine-tuning for each control cycle For a limiting function subject to constraints, This mainly refers to the limiting function constrained by pump pressure, valve opening, and nozzle angle. For the first Control items for each control cycle, For proportional gain, For integral gain, For differential gain, For the first Feedback error within each control cycle For the counting sequence number, For the first The last moment of each control cycle, From the start of the nozzle until the... The sum of feedback errors at all times within the last moment of each control cycle. For the first At that moment, For the first Feedback error within each control cycle.

[0083] As one embodiment, the feedback error may consist of the downwind smoke permeability, oxygen concentration, temperature, and the risk of reignition in the flame image.

[0084] As one embodiment, in another PID control scheme For from the first The sum of feedback errors at all times from the start to the end of each control cycle.

[0085] As one embodiment, among the various control items, those related to valve opening, spray pressure, and injection angle for each blocking zone are suitable for PID fine-tuning across control cycles. For control items with fuzzy boundaries, such as smoke permeability, visibility, and flame image confidence, low, medium, and high-risk membership functions can be set in rule-based control to form fuzzy control correction quantities.

[0086] As one embodiment, the method of using optimized control items to control the nozzle 3 to form a fog curtain also includes: obtaining feedback error based on the downwind smoke transmission rate, oxygen concentration, temperature and flame image reignition risk; if the feedback error does not drop to the set range, then adjusting in a progressive order of priority: "pressure fine-tuning - angle correction - increasing the number of fog curtain columns - increasing the number of nozzles - activating adjacent zones".

[0087] In response to the feedback error exceeding the error threshold, the nozzle 3 is progressively adjusted according to a priority sequence of actions, which includes: fine-tuning the pressure of the nozzle 3, correcting the angle of the nozzle 3, increasing the number of fog curtain columns, increasing the number of nozzles 3, and activating the fog curtain of adjacent zones.

[0088] In response to feedback errors exceeding the error threshold for multiple consecutive control cycles, the water consumption of the nozzle 3 is reduced, thereby reducing the impact of the specific problematic nozzle 3 on the overall system, and decreasing water consumption and disturbance to the ventilation system. When a ventilation network model and a valve group response model are available, model predictive control can be used to replace the above-mentioned objective function rolling optimization step.

[0089] As one embodiment, the knowledge of blockade zone types includes: upwind blockade zone, downwind smoke blocking zone, lateral compensation zone in connecting roadways, and working face blockade zone. The non-negative weights and safety weights of different types of blockade zones also differ. Within the mine roadways, blockade zones are set along the intake airway, return airway, connecting roadways, and roadways surrounding the mining working face. Along the current airflow direction, the side closer to the incoming wind direction is defined as the upwind side, and the side farther from the incoming wind direction is defined as the downwind side.

[0090] The fog control method in the tunnel provided in this embodiment uses a continuous fine water fog curtain to form a non-solid flexible sealed space, which can replace or supplement the traditional rigid sealed wall, reducing the need for material transportation, underground construction, and personnel entry into dangerous areas. A cross-sectional covering nozzle array composed of top, side, and bottom auxiliary nozzles (3) is used, and the number and spacing of nozzles are calculated through effective fog cone overlap relationships to reduce the risk of local gaps in the fog curtain and smoke bypass. Through feedback from multiple parameters such as temperature, smoke, carbon monoxide, carbon dioxide, oxygen, wind speed and direction, and flame images, the number of nozzles, spray pressure, spray direction, number of fog curtain columns, and duration are dynamically adjusted to adapt to changes in fire source location and ventilation status. The fog curtain can block smoke, weaken oxygen supply, reduce radiant heat feedback and evaporative heat absorption, achieving integrated fire control, smoke blocking, cooling, and sealing.

[0091] Example 3

[0092] refer to Figure 2 This embodiment provides a structure for generating fog in a tunnel, including a controller 1.

[0093] Sensor 2 is electrically connected to the controller 1 and is used to acquire environmental signals in each tunnel.

[0094] The nozzle 3 is electrically connected to the controller 1 and is used to form a fog curtain in the alley.

[0095] As one embodiment, various types of sensors 2 can be integrated into a single sensor node.

[0096] The fog control method in the tunnel provided in Embodiment 1 or 2 can be applied to the controller 1 in the fog generation structure in the tunnel provided in this embodiment. It has the corresponding functional modules and beneficial effects of the execution method. The fog generation structure in the tunnel provided in this embodiment has the same technical effects as Embodiment 1 or 2, and will not be described again here.

[0097] The controller 1 can perform the following actions: acquire environmental signals from each sensor 2, and obtain an escape risk score based on the environmental signals.

[0098] In response to the escape risk score reaching the disaster threshold, different types of blockade zones are selected from each alleyway based on the wind path relationship and the escape risk score.

[0099] Obtain the security policies corresponding to different types of blocking zones, construct an objective function based on the security policies, optimize the control terms using the objective function, and use the optimized control terms to control the nozzle 3 to form a fog curtain.

[0100] The escape risk score is calculated using the following formula: In the formula, For the counting sequence number, For the first Escape risk score for each sensor node , , , , , and These are non-negative weights. For the first The temperature of each sensor node, For the first The temperature rise rate of each sensor node, For the first Carbon monoxide concentration at each sensor node For the first The amount of oxygen decrease at each sensor node. For the first The decrease in flue gas permeability at each sensor node For the first Confidence of flame images from individual sensor nodes For the first Wind speed disturbance at each sensor node.

[0101] The step of selecting different types of blocking zones from various alleyways based on wind path relationships and escape risk scores includes: obtaining alleyway maps and wind direction, and abstracting the alleyway map into a directed graph based on the wind direction.

[0102] The edge weights of each alleyway in the directed graph are determined based on distance weight, wind speed weight, and the escape risk score.

[0103] A roadway whose escape risk score exceeds the fire source threshold and whose duration reaches the first time threshold is defined as a fire source section roadway.

[0104] Based on the location of the fire source section in the directed graph and the edge weight of each section in the directed graph, different types of blocking zones are selected from each section.

[0105] It also includes: setting the control cycle.

[0106] Different types of blockade zones are reselected based on the escape risk score for each control cycle; the escape risk score for each control cycle is calculated using the following formula: In the formula, For the counting sequence number, For the first The period and the th period Escape risk score for each sensor node For the first The period and the th period The temperature of each sensor node, For the first The period and the th period The temperature rise rate of each sensor node, For the first The period and the th period Carbon monoxide concentration at each sensor node For the first The period and the th period The amount of oxygen decrease at each sensor node. For the first The period and the th period The decrease in flue gas permeability at each sensor node For the first The period and the th period Confidence of flame images from individual sensor nodes For the first The period and the th period Wind speed disturbance at each sensor node.

[0107] The first time threshold is two control cycles.

[0108] The method for obtaining the duration of the control cycle is as follows: obtain the initial cycle duration.

[0109] The initial cycle duration was verified using the sensor refresh rate, the zone valve action time, and the pump group stabilization time.

[0110] The initial cycle duration that passes the verification is used as the duration of the control cycle.

[0111] The step of constructing an objective function based on the safety strategy, optimizing the control terms using the objective function, and controlling the nozzle 3 to form a fog screen using the optimized control terms includes: the objective function is as follows: In the formula, For the first The objective function for each period, , , , and These are the safety weights, The smoke permeability or visibility on the downwind side exceeds the limit. This refers to the deviation of oxygen concentration from the safe threshold for personnel. If the temperature or rate of temperature rise on the downwind side exceeds the limit, Penalty based on water consumption or drainage pressure per unit time. Penalties are imposed for risks related to personnel passage, equipment energization, and water accumulation; the safety weights are obtained through safety policies.

[0112] The optimization objective is to minimize the value of the objective function.

[0113] The constraints include: upper limit of pump unit pressure, range of zone valve opening, range of nozzle angle, drainage capacity, power supply status, and personnel evacuation status.

[0114] The control items include: valve opening degree, spray pressure, number of nozzles starting and stopping, spray angle, and number of fog curtain columns.

[0115] Based on the optimization objective, the constraints, and the objective function, the optimized control term for the current control cycle is obtained, and the optimized control term for the current control cycle is used to control the nozzle 3 to form a fog curtain.

[0116] The method of using optimized control items to control the nozzle 3 to form a fog curtain also includes: obtaining feedback error based on the smoke permeability, oxygen concentration, temperature and flame image reignition risk on the downwind side.

[0117] Based on the feedback error, the optimized control term is fine-tuned using PID control in the next control cycle to obtain the fine-tuned PID control term; in the next control cycle, the fine-tuned PID control term is used to control the nozzle 3 to form a fog curtain.

[0118] The control term after PID fine-tuning is obtained by calculation using the following formula: In the formula, For the first The control term after PID fine-tuning for each control cycle For the amplitude limiting function subject to constraints, For the first Control items for each control cycle, For proportional gain, For integral gain, For differential gain, For the first Feedback error within each control cycle For the counting sequence number, For the first The last moment of each control cycle, From the start of the nozzle until the... The sum of feedback errors at all times within the last moment of each control cycle. For the first At that moment, For the first Feedback error within each control cycle.

[0119] The method of using optimized control items to control the nozzle 3 to form a fog curtain also includes: obtaining feedback error based on the smoke permeability, oxygen concentration, temperature and flame image reignition risk on the downwind side.

[0120] In response to the feedback error exceeding the error threshold, the nozzle 3 is progressively adjusted according to a priority sequence of actions, which includes: fine-tuning the pressure of the nozzle 3, correcting the angle of the nozzle 3, increasing the number of fog curtain columns, increasing the number of nozzles 3, and activating the fog curtain of adjacent zones.

[0121] In response to feedback errors exceeding the error threshold for multiple consecutive control cycles, the water consumption of the nozzle 3 is reduced.

[0122] In one embodiment, a nozzle array consisting of linearly distributed nozzles 3 is used to form a mist curtain. The nozzle array consisting of the nozzles 3 is distributed at the top, sides, and bottom of the tunnel; for the nozzle arrays located at the top and sides of the tunnel, the number and spacing of the nozzles 3 are mainly determined by the effective mist cone diameter of the nozzles 3.

[0123] The nozzle spacing and number of nozzles in the nozzle column located at the top of the tunnel are obtained based on the effective mist cone diameter of the nozzle 3. The nozzle spacing and number of nozzles in the nozzle column located at the top of the tunnel are obtained by the following formula: In the formula, This refers to the number of nozzles located in the nozzle row at the top of the tunnel. The width of the alleyway, The nozzle spacing is the distance between the nozzles in the nozzle row located at the top of the tunnel. For the effective fog cone diameter, The effective distance from the nozzle to the target coverage area. For the spray angle, This is the longitudinal airflow reduction factor.

[0124] The nozzle spacing and number of nozzles in the nozzle row located on the side of the tunnel are obtained based on the effective mist cone diameter of the nozzle 3. The nozzle spacing and number of nozzles in the nozzle row located on the side of the tunnel are obtained by the following formula: In the formula, This refers to the number of nozzles located in the nozzle row on the side of the tunnel. The height of the tunnel, This refers to the nozzle spacing of the nozzle row located on the side of the tunnel.

[0125] For nozzle rows located at the bottom of the tunnel, when the bottom corner or equipment obstruction causes a bottom coverage gap greater than 0.3m, each nozzle row located at the bottom of the tunnel shall have at least two additional bottom auxiliary nozzles 3.

[0126] As one embodiment, a layout scheme for the number of nozzle rows is also provided: in response to the wind speed in the tunnel not exceeding 1.5m / s and the tunnel slope not exceeding 5°, a nozzle row is set at the top, side and bottom of the tunnel.

[0127] In response to a wind speed in the tunnel greater than 1.5 m / s and not exceeding 3.0 m / s, or a tunnel slope greater than 5° and not exceeding 10°, two rows of nozzles are installed at the top, side and bottom of the tunnel.

[0128] In response to a wind speed greater than 3.0 m / s in the tunnel or a slope greater than 10° in the tunnel, three rows of spray columns are set at the top, sides and bottom of the tunnel.

[0129] The distance between the diameters of adjacent spray columns shall not be less than 1m and not more than 3m.

[0130] That is, the number of fog curtain columns is determined according to the current wind speed and roadway slope: when the wind speed is ≤1.5m / s and the roadway slope is ≤5°, one fog curtain column is set up for each sealing zone.

[0131] When the wind speed is between 1.5 m / s and 3.0 m / s or the roadway slope is between 5° and 10°, two rows of fog curtains should be installed.

[0132] When the wind speed is greater than 3.0 m / s or the roadway slope is greater than 10°, three rows of fog curtains should be installed. The spacing between adjacent fog curtain rows is preferably 1 m to 3 m.

[0133] The first fog curtain is used for rapid, low-disturbance sealing; the second fog curtain is used to increase the fog curtain thickness; and the third fog curtain is used to resist penetration, entrainment, and displacement.

[0134] As one embodiment, the initial spray parameters of nozzle 3 can be: droplet size 50μm to 500μm, preferably 200μm to 400μm; spray pressure 0.5MPa to 10MPa, preferably 3MPa to 8MPa; single nozzle flow rate 10L / min to 20L / min. In actual engineering, these parameters should be adjusted based on nozzle samples, water supply capacity, tunnel cross-section, and on-site test spray results.

[0135] The nozzle 3 supplies water through a high-pressure water supply unit, which includes a water source, a high-pressure pump set, a main pipeline, zone branch pipes, zone control valves, a pressure sensor, and a flow sensor.

[0136] In one embodiment, the nozzle 3 is adjusted by a nozzle attitude adjustment unit, which can employ an electric, pneumatic, or hydraulic actuator, including an adjustable bracket, a rotary joint, an angle actuator, and a proportional valve. When upward ventilation or the chimney effect causes the fog curtain to shift to the leeward side, the pressure of the nozzle 3 on the leeward side is increased, and some nozzles 3 are deflected to the leeward side; when the flue gas flows around the top plate or side wall, the pitch and azimuth angles of the top nozzles 3 or the side nozzles 3 are adjusted; when there is a conveyor belt or equipment obstructing the bottom, the bottom auxiliary nozzles 3 are activated.

[0137] This embodiment also provides an optional initial design range. During project implementation, the initial design range can be checked or narrowed based on nozzle samples, pump capacity, tunnel cross-section, fire source scale, on-site test spray results, and feedback on sealing effect.

[0138] The initial design range for droplet size is 50-500μm, preferably 200-400μm.

[0139] The design is based on: standard definitions, product technical conditions, and engineering test verification.

[0140] The engineering verification methods include: GB50898-2013 for the design, construction, acceptance and maintenance of fine water mist systems; GB / T26785-2011 for the performance inspection of nozzles and system components; NFPA750 emphasizes the performance of listed equipment and systems proven by fire testing; 50-500μm is written as the feasible droplet range; 200-400μm is the preferred initial value that takes into account both the continuity of the mist curtain and the heat absorption of evaporation, and needs to be verified by nozzle samples, particle size testing and on-site test spraying.

[0141] The initial design range for spray pressure is 0.5-10 MPa, preferably 3-8 MPa.

[0142] The basis for this is the combination of equipment capacity and engineering adjustment range.

[0143] The engineering verification method is as follows: 0.5-10MPa is the feasible range for covering low-pressure and medium-high pressure fine water mist equipment, 3-8MPa is the preferred initial value for forming a stable cross-sectional fog curtain, and the final value is determined according to GB50898-2013 water supply and pipeline requirements, GB / T26785-2011 component test requirements, nozzle samples and on-site test spraying.

[0144] The initial design range for the flow rate of a single nozzle is 10-20 L / min.

[0145] The design was based on: nozzle samples + component testing + fog curtain continuity verification.

[0146] The engineering verification method is as follows: 10-20L / min is used as the initial flow range for a single nozzle. It is used to estimate the total flow of the same row of nozzles and the selection of pump sets. During implementation, the rated flow of the nozzle sample, the test requirements of GB / T26785-2011 for nozzles and system components, the continuity of the fog curtain and the drainage capacity on site are checked. It can be adjusted according to the actual nozzle model.

[0147] The initial design range for nozzle spacing is: and .

[0148] The design is based on: spray cone geometric coverage + safety overlap coefficient.

[0149] The engineering verification method is as follows: From the geometric projection of the spray cone; or ≤0.8 To retain approximately 20% geometric overlap, =0.6-0.8 is a reduction factor that takes into account longitudinal ventilation, chimney effect and plume deviation. The coefficient of 0.8 is verified by the nozzle sample spray angle, wind speed limit, CFD calculation or smoke tracing test.

[0150] The initial design range for the number of top nozzles is: .

[0151] The design was based on the reverse calculation of the tunnel width.

[0152] Engineering verification methods: The width of the alleyway, The formula, which specifies the spacing between the top nozzles, ensures continuous lateral coverage and is suitable for the initial design of rectangular tunnels.

[0153] The initial design range for the number of nozzles on both sides is: single-sided condition is met. .

[0154] The design is based on the reverse calculation of the tunnel height.

[0155] Engineering verification methods: The height of the tunnel, The vertical nozzle spacing is used to prevent flue gas from flowing around the sidewalls or top corners.

[0156] The initial design range for bottom auxiliary nozzles is: when the bottom coverage gap is >0.3m, there should be no less than 2 nozzles per column.

[0157] The design is based on: blind spot inspection threshold + on-site image verification.

[0158] The engineering verification method is as follows: the bottom corner, belt conveyor frame, and equipment foundation are easily blocked by fog. 0.3m is used as the bottom identifiable blind zone threshold. It is applicable to low-level flow around and equipment obstruction. On-site confirmation can be made by test spray images, laser sheet light or visible smoke tracer. If the threshold is exceeded, the bottom auxiliary nozzle is activated or the spray angle is adjusted.

[0159] The initial design range for the number of nozzle rows is as follows: when the wind speed is ≤1.5m / s and the roadway slope is ≤5°, one row of fog curtains is set for each blocking zone; when 1.5m / s < wind speed ≤3.0m / s or 5° < roadway slope ≤10°, two rows of fog curtains are set; when the wind speed is >3.0m / s or the roadway slope is >10°, three rows of fog curtains are set. The spacing between adjacent fog curtain rows is preferably 1m to 3m.

[0160] The design is based on an initial classification determined by wind speed, slope, and bypass risk.

[0161] The engineering verification method is as follows: the number of columns is graded to convert continuous variables into executable engineering actions. The wind speed threshold can be checked against the allowable wind speed of mining faces and roadways in the current "Coal Mine Safety Regulations". The slope and bypass threshold can be corrected by the roadway slope, the size of the fire source, the smoke transmission rate on the downwind side and the results of on-site test spraying.

[0162] The initial design range for sensor node spacing is: 10-30m for general applications; 5-10m for connecting roadways, working face entrances, and belt transfer points.

[0163] The design is based on the engineering layout of a mining scenario.

[0164] Engineering verification method: Based on the layout requirements of high-risk nodes in mine roadways, the locations of connecting roadway entrances, working face entrances, and belt transfer points should be densely arranged, and verified according to the on-site ventilation network and alarm response time.

[0165] In one embodiment, controller 1 can integrate various functions of the sealing system, including a fire parameter sensing unit, a zoned fine water mist curtain generating unit, a high-pressure water supply unit, a nozzle attitude adjustment unit, a linkage control unit, and a safety interlock unit. The zoned fine water mist curtain generating units are installed in the intake airway, return airway, connecting airway, and surrounding roadways of the mining face, and include at least a sealing zone on the upwind side of the fire source, a smoke-blocking zone on the downwind side of the fire source, a lateral compensation zone in the connecting airway, and a sealing zone on the working face side. Each sealing zone has one to three rows of fine water mist curtains. Each mist curtain consists of a top nozzle 3, two side nozzles 3, and a bottom auxiliary nozzle 3, suitable for full coverage of the cross-section of rectangular roadways; for arched or irregular roadways, side compensation nozzles can be added according to the same effective mist cone overlap principle. The linkage control unit adopts a closed-loop control algorithm of "risk scoring—zone selection—parameter optimization—feedback correction". Control inputs include temperature, temperature rise rate, carbon monoxide, carbon dioxide, oxygen, smoke permeability, wind speed and direction, flame image confidence level, and water pressure and flow rate; control outputs include zone valve opening, spray pressure, number of nozzles activated and deactivated, spray angle, number of fog curtain columns, and continuous spraying time. The linkage control unit determines the blocking strategy based on sensor information: for fires in the intake airway, priority is given to activating the upwind blocking fog curtain and the downwind smoke barrier; for fires near the mining face or intake / return air connecting roadways, the working face blocking fog curtain, the return air smoke barrier, and the connecting roadway compensation fog curtain are activated. The number of nozzles, spray pressure, spray direction, number of fog curtain columns, and duration can be dynamically adjusted according to the smoke blocking effect. The fire parameter sensing unit sets sensor nodes on the upwind and downwind sides of each blocking zone, with a conventional longitudinal spacing of 10m to 30m; at connecting roadway entrances, mining face entrances, belt conveyor transfer points, electromechanical chambers, roadway intersections, and locations where smoke bypass may occur, the node spacing is increased to 5m to 10m. The linkage control algorithm can be executed according to discrete control cycles, and by default adopts a combined control scheme of "rule-based partitioning + objective function rolling optimization + PID fine-tuning". The linkage control process is as follows: collect fire field parameters; calculate the risk score of each sensor node; identify the fire source location, airflow direction and smoke spread path; select the upwind blocking zone, downwind smoke blocking zone and lateral communication compensation zone based on the roadway topology map; calculate the number of nozzles and the number of activation columns according to the roadway cross section; activate the corresponding zone nozzle array to form a continuous cross-sectional fog curtain; and perform feedback adjustment based on the downwind smoke concentration, fog curtain transmittance, oxygen concentration, temperature and flame image.

[0166] The fog curtain generation structure provided in this embodiment faces the mine's intake airway, return airway, connecting airway, and surrounding airways of the mining face. It sets up independently operable fine water fog curtain blocking zones at different locations, and arranges a nozzle array capable of covering the cross-section of the airway in each blocking zone. The system uses sensor information such as temperature, smoke, carbon monoxide, carbon dioxide, oxygen, wind speed and direction, and flame images to determine the location of the fire source and the smoke spread path. It then activates the upwind blocking fog curtain, the downwind smoke blocking fog curtain, and the lateral compensation fog curtain in the connecting airway, forming a non-physical flexible sealed space composed of continuous fine water fog curtains. This embodiment can replace or supplement traditional rigid sealed walls for rapid early-stage sealing of external fires in mines, blocking smoke, reducing oxygen supply, cooling and insulating, and promoting fire source attenuation. The fine water fog curtain can quickly form multiple flexible sealed barriers—upwind blocking, downwind smoke blocking, and lateral compensation—based on the location of the fire source, airflow direction, and smoke spread status. In this embodiment, multiple fine water mist blocking zones that can be independently started and stopped are pre-set in the mine ventilation network. The location of the fire source, the direction of airflow and the path of smoke spread are identified by multi-parameter sensor nodes, and then the corresponding blocking zones are selected to form multiple continuous fine water mist curtains.

[0167] The fog curtain generation structure in this embodiment uses a continuous fine water fog curtain to form a non-solid flexible sealed space, which can replace or supplement traditional rigid sealed walls, reducing the need for material transportation, underground construction, and personnel entry into dangerous areas. The cross-sectional coverage nozzle array composed of top, side, and bottom auxiliary nozzles (3), and the calculation of the nozzle number and spacing through effective fog cone overlap, can reduce the risk of local gaps in the fog curtain and smoke bypass. Through feedback from multiple parameters such as temperature, smoke, carbon monoxide, carbon dioxide, oxygen, wind speed and direction, and flame images, the number of nozzles, spray pressure, spray direction, number of fog curtain columns, and duration can be dynamically adjusted to adapt to changes in fire source location and ventilation status. The fog curtain can block smoke, weaken oxygen supply, reduce radiative heat feedback and evaporative heat absorption, achieving integrated fire control, smoke blocking, cooling, and sealing.

[0168] refer to Figure 3 A fire source 100 appears in the middle of the intake airway 101. The location of the fire source 100 can be determined by the two sensor nodes 110 before and after the fire source 100. A fine water mist curtain 130 is generated before and after the fire source 100. The fine water mist curtain 130 is controlled by the zone control valve 120. Referring to the arrow of the direction of smoke spread in the figure, a fine water mist curtain 130 is set at the connecting airway 103 to block the spread of smoke. A fine water mist curtain 130 is also set at the junction of the working face passage 105 and the mining working face 104 along the threat path of the working face. However, no fine water mist curtain 130 is set at the return airway 102.

[0169] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0170] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0171] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0172] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0173] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0174] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0175] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for controlling fog in a tunnel, characterized in that, include: Obtain environmental signals from each sensor (2) and obtain an escape risk score based on the environmental signals; In response to the escape risk score reaching the disaster threshold, different types of blockade zones are selected from each alleyway based on the wind path relationship and the escape risk score; Obtain the security policies corresponding to different types of blocking zones, construct the objective function according to the security policy, optimize the control terms using the objective function, and use the optimized control terms to control the nozzle (3) to form a fog screen; The escape risk score is calculated using the following formula: ， In the formula, For the counting sequence number, For the first Escape risk score for each sensor node , , , , , and These are non-negative weights. For the first The temperature of each sensor node, For the first The temperature rise rate of each sensor node, For the first Carbon monoxide concentration at each sensor node For the first The amount of oxygen decrease at each sensor node. For the first The decrease in flue gas permeability at each sensor node For the first Confidence of flame images from individual sensor nodes For the first Wind speed disturbance at each sensor node; The selection of different types of blocking zones from various alleyways based on wind path relationships and escape risk scores includes: Obtain the tunnel map and wind direction, and abstract the tunnel map into a directed graph based on the wind direction; The edge weights of each alleyway in the directed graph are determined based on distance weights, wind speed weights, and the escape risk score. A roadway whose escape risk score exceeds the fire source threshold and whose duration reaches the first time threshold is defined as a fire source section roadway. Based on the position of the fire source section in the directed graph and the edge weight of each section in the directed graph, different types of blocking zones are selected from each section. Set the control cycle; Different types of blockade zones are reselected based on the escape risk score for each control cycle; The step of constructing an objective function based on the safety strategy, optimizing the control terms using the objective function, and controlling the nozzle (3) to form a fog curtain using the optimized control terms includes: The objective function is as follows: ， In the formula, For the first The objective function for each period, , , , and These are the safety weights, The smoke permeability or visibility on the downwind side exceeds the limit. This refers to the deviation of oxygen concentration from the safe threshold for personnel. If the temperature or rate of temperature rise on the downwind side exceeds the limit, Penalty based on water consumption or drainage pressure per unit time. Penalties are imposed for risks related to personnel passage, energized equipment, and water accumulation; the safety weights are obtained through safety policies. The optimization objective is to minimize the function value of the objective function. The constraints include: upper limit of pump unit pressure, range of zone valve opening, range of nozzle angle, drainage capacity, power supply status, and personnel evacuation status; Control items include: valve opening, spray pressure, number of nozzles started and stopped, spray angle, and number of fog columns; Based on the optimization objective, the constraints and the objective function, the optimized control term for this control cycle is obtained, and the optimized control term for this control cycle is used to control the nozzle (3) to form a fog curtain.

2. The method for controlling fog in a tunnel according to claim 1, characterized in that, it further... include: The escape risk score for each control cycle is calculated using the following formula: ， In the formula, For the counting sequence number, For the first The period and the th period Escape risk score for each sensor node For the first The period and the th period The temperature of each sensor node, For the first The period and the th period The temperature rise rate of each sensor node, For the first The period and the th period Carbon monoxide concentration at each sensor node For the first The period and the th period The amount of oxygen decrease at each sensor node. For the first The period and the th period The decrease in flue gas permeability at each sensor node For the first The period and the th period Confidence of flame images from individual sensor nodes For the first The period and the th period Wind speed disturbance at each sensor node; The first time threshold is two control cycles; The method for obtaining the duration of the control cycle is as follows: Obtain the initial cycle duration; The initial cycle duration was verified using the sensor refresh rate, the zone valve action time, and the pump group stabilization time. The initial cycle duration that passes the verification is used as the duration of the control cycle.

3. The method for controlling fog in a tunnel according to claim 1, characterized in that, The method of using optimized control terms to control the nozzle (3) to form a fog screen also includes: Feedback error is obtained based on the smoke permeability, oxygen concentration, temperature, and flame image reignition risk on the downwind side; Based on the feedback error, the optimized control term is fine-tuned using PID in the next control cycle to obtain the fine-tuned control term; in the next control cycle, the fine-tuned control term is used to control the nozzle (3) to form a fog curtain; The control term after PID fine-tuning is obtained by calculation using the following formula: ， In the formula, For the first The control term after PID fine-tuning for each control cycle For the amplitude limiting function subject to constraints, For the first Control items for each control cycle, For proportional gain, For integral gain, For differential gain, For the first Feedback error within each control cycle For the counting sequence number, For the first The last moment of each control cycle, From the start of the nozzle until the... The sum of feedback errors at all times within the last moment of each control cycle. For the first At that moment, For the first Feedback error within each control cycle.

4. The method for controlling fog in a tunnel according to claim 1, characterized in that, The method of using optimized control terms to control the nozzle (3) to form a fog screen also includes: Feedback error is obtained based on the smoke permeability, oxygen concentration, temperature, and flame image reignition risk on the downwind side; In response to the feedback error exceeding the error threshold, the nozzle (3) is progressively adjusted according to the priority sequence of actions, which is: fine-tuning the pressure of the nozzle (3), correcting the angle of the nozzle (3), increasing the number of fog columns, increasing the number of nozzles (3), and activating the fog of adjacent zones. In response to feedback errors exceeding the error threshold for multiple consecutive control cycles, the water consumption of the nozzle (3) is reduced.

5. A structure for generating fog in a tunnel, characterized in that, include: Controller (1) is used to execute the control method for fog curtain in a tunnel as described in any one of claims 1 to 4; Sensor (2) is electrically connected to the controller (1) and is used to acquire environmental signals in each roadway; The nozzle (3) is electrically connected to the controller (1) and is used to form a fog curtain in the tunnel.

6. The fog curtain generation structure in the tunnel according to claim 5, characterized in that, it also... include: The nozzle array, consisting of the nozzles (3), is distributed at the top, sides, and bottom of the tunnel; The nozzle spacing and number of nozzles in the nozzle column at the top of the tunnel are obtained based on the effective mist cone diameter of the nozzle (3). The nozzle spacing and number of nozzles in the nozzle column at the top of the tunnel are obtained by the following formula: ， In the formula, This refers to the number of nozzles located in the nozzle row at the top of the tunnel. The width of the alleyway, The nozzle spacing is the distance between the nozzles in the nozzle row located at the top of the tunnel. For the effective fog cone diameter, The effective distance from the nozzle to the target coverage area. For the spray angle, This is the longitudinal airflow reduction factor; The nozzle spacing and number of nozzles in the nozzle row located on the side of the tunnel are obtained based on the effective mist cone diameter of the nozzle (3). The nozzle spacing and number of nozzles in the nozzle row located on the side of the tunnel are obtained by the following formula: ， In the formula, This refers to the number of sprinklers located in the sprinkler row on the side of the tunnel. The height of the tunnel, This refers to the nozzle spacing of the nozzle row located on the side of the tunnel.

7. The fog curtain generation structure in the tunnel according to claim 6, characterized in that, Also includes; In response to the wind speed in the tunnel not exceeding 1.5 m / s and the tunnel slope not exceeding 5°, a row of nozzles is installed at the top, side and bottom of the tunnel. In response to a wind speed in the tunnel greater than 1.5 m / s and not exceeding 3.0 m / s, or a tunnel slope greater than 5° and not exceeding 10°, two rows of nozzles are installed at the top, side and bottom of the tunnel. In response to a wind speed greater than 3.0 m / s in the tunnel or a slope greater than 10° in the tunnel, three rows of nozzles are installed at the top, sides and bottom of the tunnel. The distance between the diameters of adjacent nozzle rows shall not be less than 1m and not more than 3m.

Images