Tunnel construction ventilation control method and system based on internet of things

Abstract

The application discloses a tunnel construction ventilation control method and system based on the Internet of Things, and relates to the technical field of intelligent control, and comprises the following steps: simulating tunnel ventilation to obtain a tunnel flow field diagram and an air flow area, calculating dust deposition velocities of each air flow area, sending a first control signal, performing a first operation, presetting a transition time point, and performing second control. The application dynamically adjusts ventilation parameters through real-time data, avoids poor ventilation effect or energy waste caused by fixed parameters in a traditional ventilation system, optimizes ventilation parameters, ensures that the dust concentration in the tunnel is always within a safe range, dynamically controls the ventilation system to quickly respond to changes in the construction process, guarantees construction safety, intelligently controls ventilation parameters, avoids unnecessary energy waste, flexibly adjusts ventilation parameters according to different tunnel construction conditions, and has strong adaptability and saves power.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intelligent control, and in particular to a tunnel construction ventilation control method and system based on the Internet of Things. BACKGROUND

[0002] In recent years, the Internet of Things technology has realized the automation and intelligent management of the tunnel ventilation system, reduced manual intervention and management costs, and automatically adjusted the operation strategy of the fan according to the monitored environmental data and traffic flow prediction by using the Internet of Things technology and combining intelligent algorithms.

[0003] At present, in the Chinese patent with the publication number CN106321487A, a three-section tunnel construction ventilation control method is disclosed, which rapidly improves the environment of the tunnel face, shortens the time of workers entering the site, and gradually adjusts the fan operation frequency to the minimum air speed that meets the on-site air demand through a fuzzy neural network algorithm, and keeps the air flowing by running at the minimum air speed, but the related art does not select an ideal ventilation pipe layout according to the shape distribution of the tunnel, which easily causes dust backflow, is not conducive to the health of workers, does not combine harmful gases and dust for regulation and control, and is not conducive to the comprehensiveness and accuracy of regulation and control, and has certain limitations. SUMMARY

[0004] The technical problem solved by the present application is that the related art does not select an ideal ventilation pipe layout according to the shape distribution of the tunnel, which easily causes dust backflow, is not conducive to the health of workers, does not combine harmful gases and dust for regulation and control, and is not conducive to the comprehensiveness and accuracy of regulation and control, and has certain limitations.

[0005] To solve the above technical problems, the present application provides the following technical solutions: in a first aspect, a tunnel construction ventilation control method based on the Internet of Things, comprising the following steps:

[0006] Step S100: acquiring a tunnel face picture, matching a first ventilation parameter according to the tunnel face picture, simulating tunnel ventilation according to the first ventilation parameter to obtain a tunnel flow field map, and obtaining an air flow region according to the tunnel flow field map;

[0007] Step S200: detecting a dust parameter of the air flow region, calculating a dust settling velocity of each air flow region according to the Stokes formula;

[0008] Step S300: issuing a first regulation and control signal according to the dust settling velocity of each air flow region, performing a first regulation and control on the first ventilation parameter according to the first regulation and control signal to obtain a second ventilation parameter, and performing a first operation according to the gas parameter of each air flow region after the first regulation and control;

[0009] Step S400, according to the dust concentration and gas parameters after the first operation, preset the transition time point, and the second ventilation parameter is controlled after the transition time point.

[0010] As a preferred scheme of the tunnel construction ventilation control method based on Internet of Things, the first ventilation parameter comprises air volume and air pressure.

[0011] The air flow region comprises a jet flow region, a vortex flow region and a backflow region.

[0012] A tunnel face picture is acquired, a tunnel shape database is called, and any standard tunnel face picture is acquired from the tunnel shape database, the tunnel shape database comprising standard tunnel shape names and corresponding standard tunnel face pictures, and the standard tunnel shape names comprising a straight line type tunnel, a roadway and a spiral line type tunnel.

[0013] A first feature quantity of the tunnel face picture is extracted, and a second feature quantity of the standard tunnel face picture is extracted, the first feature quantity and the second feature quantity being shape feature quantities, a first similarity between the first feature quantity and the second feature quantity being calculated by a cosine similarity formula, a first value being set as a similarity threshold value, the first similarity and the first value being compared, and when the first similarity is greater than or equal to the first value, a standard tunnel shape name corresponding to the second feature quantity is set as a current tunnel shape name.

[0014] As a preferred scheme of the tunnel construction ventilation control method based on Internet of Things, a ventilation database is called, and the ventilation database comprises tunnel shape names, corresponding distances between air cylinder openings and working faces, corresponding air cylinder cross-sectional areas, corresponding distribution positions of air cylinders in tunnels, corresponding air volumes and corresponding air pressures.

[0015] The current tunnel shape name is input into the ventilation database to obtain the corresponding distances between the air cylinder openings and the working faces, the corresponding air cylinder cross-sectional areas, the corresponding distribution positions of the air cylinders in the tunnels, the corresponding air volumes and the corresponding air pressures, the type of the air cylinder is selected according to the corresponding distances between the air cylinder openings and the working faces, the corresponding air cylinder cross-sectional areas and the corresponding distribution positions of the air cylinders in the tunnels, the layout of the air cylinder in the tunnel is set, and the corresponding air volume and the corresponding air pressure are set as the first ventilation parameter.

[0016] As a preferred scheme of the tunnel construction ventilation control method based on Internet of Things, the construction blasting is simulated according to the first ventilation parameter to obtain a tunnel flow field diagram, and the air flow region is obtained according to the tunnel flow field diagram.

[0017] Input the tunnel curvature radius, the tunnel length and the distance from the air outlet of the air duct to the tunnel face into the simulation software, construct a tunnel ventilation model, take the second value as the air inlet velocity, obtain a tunnel flow field diagram, and divide the tunnel flow field diagram into air flow regions according to the preset air flow region division knowledge spectrum.

[0018] As a preferred scheme of the tunnel construction ventilation control method based on the Internet of Things, the preset air flow region division knowledge spectrum comprises:

[0019] The region in which the air flow direction is mainly along the axial direction of the air duct is set as a jet flow region.

[0020] The region in which the air flow direction is in a rotating state is set as an eddy flow region.

[0021] The region with the first distance to the tunnel face and the direction opposite to that of the jet flow region is set as a backflow region.

[0022] As a preferred scheme of the tunnel construction ventilation control method based on the Internet of Things, the dust parameters of the air flow region are detected by the sensor array of the Internet of Things front end, and the dust parameters include dust density, air density, gravitational acceleration, air dynamic viscosity, dust particle diameter, dust specific gravity and air specific gravity.

[0023] The Stokes formula is called, the dust parameters of the air flow region are input into the Stokes formula, and the dust settling velocity of the corresponding air flow region is calculated.

[0024] As a preferred scheme of the tunnel construction ventilation control method based on the Internet of Things, the third value is set as a settling velocity threshold.

[0025] Any air flow region is obtained, the settling velocities of each dust in the air flow region are obtained, the settling velocities of each dust in the air flow region are sorted in descending order, the largest settling velocity is selected, the largest settling velocity is set as the critical velocity of the air flow region, each air flow region is traversed, and the corresponding critical velocity of each air flow region is set.

[0026] The corresponding critical velocities of each air flow region are compared with the third value, when there is a critical velocity greater than the third value, a first control signal is sent, and when all the critical velocities are less than or equal to the third value, the first control signal is not sent.

[0027] When the first control signal is sent, the first ventilation parameter is controlled, and the first control method comprises:

[0028] The change gradient of the wind volume is the fourth value, the change gradient of the wind pressure is the fifth value, the wind volume is continuously changed according to the fourth value, the wind pressure is continuously changed according to the fifth value, and the wind volume and the wind pressure do not exceed the maximum bearing wind volume and the maximum bearing wind pressure of the air pipe;

[0029] Until all the critical speeds are less than or equal to the third value, the first regulation is not performed.

[0030] As a preferred scheme of the tunnel construction ventilation control method based on the Internet of Things, the first ventilation parameter after the first regulation is set as a second ventilation parameter, the gas parameters of each air flow region after the first regulation are obtained, and the concentration threshold range of each gas parameter is obtained according to the construction safety standard.

[0031] The gas parameters include carbon monoxide volume concentration, carbon dioxide gas concentration, nitrogen oxide gas concentration, sulfide gas volume concentration, and oxygen concentration, and the first operation is performed according to the gas parameters of each air flow region after the first regulation.

[0032] The first operation includes regulating the second ventilation parameter and not regulating the second ventilation parameter, when there is a gas parameter not distributed in the corresponding concentration threshold range, the first operation is set to regulate the second ventilation parameter, and when all the gas parameters are distributed in the corresponding concentration threshold range, the first operation is set to not regulate the second ventilation parameter.

[0033] When the first operation is to regulate the second ventilation parameter, the wind volume change gradient is the seventh value, the wind pressure change gradient is the eighth value, the wind volume is continuously increased according to the seventh value, the wind pressure is continuously increased according to the eighth value, and the wind volume and the wind pressure do not exceed the maximum bearing wind volume and the maximum bearing wind pressure of the air pipe, until all the gas parameters are distributed in the corresponding concentration threshold range, the regulation of the second ventilation parameter is stopped.

[0034] When the first operation is not to regulate the second ventilation parameter, the second ventilation parameter is not regulated.

[0035] As a preferred scheme of the tunnel construction ventilation control method based on the Internet of Things, a first time period is taken as an interval time period, the dust concentration and the gas parameters after each interval time period after the first operation are obtained, and a dust concentration sequence and a gas parameter sequence are obtained.

[0036] The first difference value of adjacent dust concentrations or adjacent gas concentrations is calculated, the first difference value is represented as time sequence adjacent, the first ratio of the first difference value to the previous one of the adjacent dust concentrations is calculated, or the first ratio of the first difference value to the previous one of the adjacent gas concentrations is calculated, the ninth value is set as the change rate threshold, each first ratio is compared with the ninth value, when the first ratio is less than or equal to the ninth value, the corresponding dust concentration or gas concentration is retained, and when the first ratio is greater than the ninth value, the corresponding dust concentration or gas concentration is deleted;

[0037] The time point corresponding to the earliest time sequence dust concentration or gas concentration is selected, the time point corresponding to the earliest time sequence dust concentration or gas concentration is set as a transition time point, and the transition time point is preset;

[0038] The second ventilation parameter is secondly regulated after the transition time point, the second regulation includes continuously reducing the wind speed and continuously reducing the air volume, so that the dust concentration and the gas concentration are distributed in the standard dust concentration distribution range and the standard gas concentration distribution range, the minimum wind speed and air volume are selected, and constant ventilation is performed at the minimum wind speed and air volume.

[0039] In a second aspect, a tunnel construction ventilation control system based on the Internet of Things includes a division module, a calculation module, and a regulation module.

[0040] The division module is configured to obtain a tunnel face picture, match a first ventilation parameter according to the tunnel face picture, simulate tunnel ventilation according to the first ventilation parameter, obtain a tunnel flow field map, and obtain an air flow region according to the tunnel flow field map.

[0041] The calculation module is configured to detect dust parameters of the air flow region, and calculate dust settling velocities of each air flow region according to the Stokes formula.

[0042] The regulation module is configured to send a first regulation signal according to the dust settling velocities of each air flow region, perform a first regulation on the first ventilation parameter according to the first regulation signal to obtain a second ventilation parameter, perform a first operation according to the gas parameters of each air flow region after the first regulation, and preset a transition time point according to the dust concentration and the gas parameters after the first operation, and perform a second regulation on the second ventilation parameter after the transition time point.

[0043] The beneficial effects of the present application: through the Internet of Things technology, the image and dust parameters in the tunnel are obtained in real time, the automation and intelligent control of the ventilation system are realized, the ventilation parameters are dynamically adjusted according to the real-time data, and the poor ventilation effect or energy waste caused by fixed parameters in the traditional ventilation system is avoided, the ventilation parameters are optimized, the dust concentration in the tunnel is ensured to be always within a safe range, the risk of construction personnel exposed to harmful dust environment is reduced, the ventilation system is dynamically controlled to quickly respond to changes in the construction process, such as sudden increase of dust concentration after blasting operation, ventilation strategy is adjusted in time to ensure construction safety, intelligent control of ventilation parameters avoids unnecessary energy waste, ventilation parameters are flexibly adjusted according to different tunnel construction conditions, and the adaptability and power saving are high. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 The basic flowchart of the tunnel construction ventilation control method based on the Internet of Things provided by an embodiment of the present application is shown. DETAILED DESCRIPTION

[0045] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments.

[0046] Embodiments, refer to Figure 1 For an embodiment of the present application, a tunnel construction ventilation control method based on the Internet of Things is provided, including the following steps:

[0047] Step S100, acquiring a tunnel face picture, matching a first ventilation parameter according to the tunnel face picture, simulating tunnel ventilation according to the first ventilation parameter, obtaining a tunnel flow field diagram, and obtaining an air flow area according to the tunnel flow field diagram;

[0048] Step S200, detecting dust parameters of the air flow area, calculating dust settling velocities of each air flow area according to the Stokes formula;

[0049] Step S300, issuing a first control signal according to the dust settling velocities of each air flow area, performing first control on the first ventilation parameter according to the first control signal, obtaining a second ventilation parameter, and performing a first operation according to the gas parameters of each air flow area after the first control;

[0050] Step S400, according to the dust concentration and gas parameters after the first operation, presetting a transition time point, and performing second control on the second ventilation parameter after the transition time point.

[0051] The present application realizes the automation and intelligent control of the ventilation system by acquiring the images and dust parameters in the tunnel in real time through the Internet of Things technology, dynamically adjusts the ventilation parameters according to the real-time data, avoids the poor ventilation effect or energy waste caused by fixed parameters in the traditional ventilation system, optimizes the ventilation parameters to ensure that the dust concentration in the tunnel is always within a safe range, reduces the risk of construction personnel exposed to harmful dust environment, dynamically controls the ventilation system to quickly respond to changes in the construction process, such as sudden increase in dust concentration after blasting operation, adjusts the ventilation strategy in time to ensure construction safety, intelligently controls the ventilation parameters to avoid unnecessary energy waste, and flexibly adjusts the ventilation parameters according to different tunnel construction conditions, which has strong adaptability and saves power.

[0052] The first ventilation parameter includes air volume and air pressure;

[0053] The airflow area includes a jet flow area, a vortex flow area, and a backflow area;

[0054] The tunnel face picture is acquired, and any standard tunnel face picture is acquired from the tunnel shape database, the tunnel shape database includes standard tunnel shape names and corresponding standard tunnel face pictures, and the standard tunnel shape names include straight-line tunnels, roadways, and spiral-line tunnels.

[0055] The first feature quantity of the tunnel face picture is extracted, and the second feature quantity of the standard tunnel face picture is extracted, the first feature quantity and the second feature quantity are represented as shape feature quantities, the first similarity of the first feature quantity and the second feature quantity is calculated through a cosine similarity formula, the first value is set as a similarity threshold, the first similarity and the first value are compared, and when the first similarity is greater than or equal to the first value, the standard tunnel shape name corresponding to the second feature quantity is set as the current tunnel shape name.

[0056] In specific implementation, the tunnel shape is accurately identified through image recognition technology, and appropriate ventilation parameters are matched according to the shape to ensure that the ventilation system can better adapt to the actual conditions of the tunnel, different shapes of the tunnel (such as straight-line, spiral-line) have different ventilation demands, accurate matching improves ventilation efficiency, real-time monitoring of dust concentration and gas parameters, dynamic adjustment of ventilation parameters according to dust settling velocity, ensure that the ventilation effect is always in the best state, through phased control (such as first control and second control), changes in the construction process can be quickly responded to, different construction stages and environmental conditions are adapted to, ventilation parameters are intelligently controlled, and unnecessary energy waste is avoided. For example, when the dust concentration is low, the air volume is appropriately reduced to save power.

[0057] Access the ventilation database, which includes the tunnel shape name, the corresponding distance between the air duct opening and the working face, the corresponding air duct cross-sectional area, the corresponding distribution position of the air duct in the tunnel, the corresponding air volume and the corresponding air pressure;

[0058] Input the current tunnel shape name into the ventilation database to obtain the corresponding distance between the air duct opening and the working face, the corresponding air duct cross-sectional area, the corresponding distribution position of the air duct in the tunnel, the corresponding air volume and the corresponding air pressure, select the type of air duct according to the corresponding distance between the air duct opening and the working face, the corresponding air duct cross-sectional area and the corresponding distribution position of the air duct in the tunnel, and set the layout of the air duct in the tunnel, and set the corresponding air volume and the corresponding air pressure as the first ventilation parameter.

[0059] In specific implementation, the ventilation parameters are accurately matched according to the tunnel shape and construction conditions through the ventilation database, so as to ensure that the ventilation system can better adapt to the actual needs of the tunnel. Different shapes of tunnels have different requirements for ventilation parameters. Accurate matching improves ventilation efficiency and reduces dust accumulation. According to the distance between the air duct opening and the working face, the air duct cross-sectional area and the distribution position, the type of air duct is reasonably selected and the layout is set. Optimizing the layout of the air duct ensures uniform airflow distribution, reduces ventilation dead angles, and improves ventilation effect. Accurate matching of ventilation parameters and optimization of air duct layout can effectively reduce the dust concentration in the tunnel, reduce the risk of construction personnel exposed to harmful dust environment, combine with Internet of Things technology, real-time monitor the dust concentration and gas parameters in the tunnel, once abnormal situation is found, timely send early warning signal, take corresponding measures, provide real-time data support for construction management personnel, facilitate timely adjustment of construction plan and ventilation strategy.

[0060] Simulate the construction blasting according to the first ventilation parameter to obtain a tunnel flow field diagram, and obtain an air flow region according to the tunnel flow field diagram;

[0061] Input the tunnel curvature radius, tunnel length and distance between air duct outlet and tunnel face into the simulation software to construct a tunnel ventilation model, set the second value as the inlet air velocity to obtain a tunnel flow field diagram, and divide the tunnel flow field diagram into an air flow region according to a preset air flow region division knowledge spectrum.

[0062] In specific implementation, the ventilation effect in the tunnel is more accurately simulated by accurately inputting the geometric parameters and ventilation parameters of the tunnel. The simulation result directly shows the air flow distribution and velocity field in the tunnel, which provides a basis for the optimization of ventilation parameters. Dynamic division helps to timely find problems in the ventilation system, such as air flow dead angle or excessive wind speed, so that corresponding control measures can be taken. A reasonable ventilation system can quickly discharge dust and harmful gases after blasting, and protect the health of construction personnel.

[0063] The preset air flow region division knowledge spectrum includes:

[0064] The region in which the wind flow direction is mainly along the axis direction of the air duct is set as a jet flow region;

[0065] The region in which the wind flow direction is in a rotating state is set as an eddy flow region;

[0066] The region at a first distance from the working face and in the opposite direction of the wind flow direction of the jet flow region is set as a backflow region.

[0067] In specific implementation, by defining the division criteria of the jet flow region, the eddy flow region and the backflow region, the ventilation condition in the tunnel can be more accurately identified, so that the ventilation design is targetedly optimized, different ventilation strategies are adopted according to the characteristics of different regions, the air volume is increased in the jet flow region to improve the ventilation effect, the measures such as spraying dust reduction are adopted in the eddy flow region, and the air duct position is adjusted or the local ventilation equipment is added in the backflow region. By identifying and optimizing the ventilation condition of the eddy flow region and the backflow region, the accumulation of dust and harmful gas is effectively reduced, the risk of construction personnel exposed to harmful environment is reduced, by accurately dividing the wind flow region, the generation of ventilation dead angle is avoided, the airflow distribution in the tunnel is ensured to be more uniform, the ventilation design is optimized to reduce the operation time and power of the ventilation equipment, so that the energy consumption is reduced, and energy saving and consumption reduction are realized.

[0068] The dust parameters of the wind flow region are detected through the sensor array of the Internet of Things front end, and the dust parameters include dust density, air density, gravitational acceleration, air dynamic viscosity, dust particle diameter, dust specific gravity and air specific gravity;

[0069] The Stokes formula is called, the dust parameters of the wind flow region are input into the Stokes formula, and the dust settling velocity of the corresponding wind flow region is calculated.

[0070] The third value is set as a settling velocity threshold;

[0071] Any wind flow region is obtained, the settling velocities of each dust in the wind flow region are obtained, the settling velocities of each dust in the wind flow region are sorted in descending order, the largest settling velocity is selected, the largest settling velocity is set as the critical velocity of the wind flow region, each wind flow region is traversed, and the corresponding critical velocity of each wind flow region is set;

[0072] The corresponding critical velocities of each wind flow region are compared with the third value, when there is a critical velocity greater than the third value, a first control signal is sent, and when all the critical velocities are less than or equal to the third value, the first control signal is not sent;

[0073] When the first control signal is sent, the first ventilation parameter is controlled, and the first control method includes:

[0074] The fourth value is used as the wind volume change gradient, the fifth value is used as the wind pressure change gradient, the wind volume is continuously changed according to the fourth value, the wind pressure is continuously changed according to the fifth value, and the wind volume and the wind pressure do not exceed the maximum bearing wind volume and the maximum bearing wind pressure of the air pipe;

[0075] Until all the critical velocities are less than or equal to the third value, the first regulation is not performed.

[0076] In specific implementation, by real-time calculation and comparison of the critical velocity of the dust and the threshold value, the ventilation parameters are dynamically adjusted to ensure that the dust settling velocity always meets the requirements, the dynamic regulation quickly responds to the change of the dust concentration in the tunnel, the adaptability and efficiency of the ventilation system are improved, unnecessary energy waste is avoided by accurately regulating the ventilation parameters. For example, when the dust concentration is low, the wind volume and the wind pressure are appropriately reduced to save power.

[0077] The first ventilation parameter after the first regulation is set as the second ventilation parameter, the gas parameters of each air flow area after the first regulation are obtained, and the concentration threshold range of each gas parameter is obtained according to the construction safety standard;

[0078] The gas parameters include carbon monoxide volume concentration, carbon dioxide gas concentration, nitrogen oxide gas concentration, sulfide gas volume concentration, and oxygen concentration, and the first operation is performed according to the gas parameters of each air flow area after the first regulation;

[0079] The first operation includes regulating the second ventilation parameter and not regulating the second ventilation parameter, when there is a gas parameter not distributed in the corresponding concentration threshold range, the first operation is set to regulate the second ventilation parameter, and when all the gas parameters are distributed in the corresponding concentration threshold range, the first operation is set to not regulate the second ventilation parameter;

[0080] When the first operation is to regulate the second ventilation parameter, the seventh value is used as the wind volume change gradient, the eighth value is used as the wind pressure change gradient, the wind volume is continuously increased according to the seventh value, the wind pressure is continuously increased according to the eighth value, and the wind volume and the wind pressure do not exceed the maximum bearing wind volume and the maximum bearing wind pressure of the air pipe, and when all the gas parameters are distributed in the corresponding concentration threshold range, the regulation of the second ventilation parameter is stopped;

[0081] When the first operation is not to regulate the second ventilation parameter, the second ventilation parameter is not regulated.

[0082] In specific implementation, the tunnel construction ventilation control method based on gas parameter monitoring and dynamic regulation ensures that the gas environment in the tunnel is always within a safe range by real-time monitoring and adjustment of the ventilation parameters, not only improves the ventilation efficiency and construction safety, but also realizes energy saving and consumption reduction, has strong practicality and popularization value, and is suitable for various complex tunnel construction environments.

[0083] In the first time interval, the dust concentration and the gas parameter after the first operation are obtained to obtain a dust concentration sequence and a gas parameter sequence;

[0084] The first difference value of the adjacent dust concentration or the adjacent gas concentration is calculated, and the first difference value is calculated with the first ratio of the previous dust concentration in the adjacent dust concentration or the first ratio of the previous gas concentration in the adjacent gas concentration. The ninth value is set as the change rate threshold value, and each first ratio is compared with the ninth value. When the first ratio is less than or equal to the ninth value, the corresponding dust concentration or gas concentration is retained, and when the first ratio is greater than the ninth value, the corresponding dust concentration or gas concentration is deleted.

[0085] The time point corresponding to the earliest time sequence dust concentration or gas concentration is selected, and the time point corresponding to the earliest time sequence dust concentration or gas concentration is set as a transition time point.

[0086] The second ventilation parameter is controlled after the transition time point, and the second control includes continuously reducing the wind speed and continuously reducing the air volume, so that the dust concentration and the gas concentration are distributed in the standard dust concentration distribution range and the standard gas concentration distribution range. The smallest wind speed and air volume are selected, and constant ventilation is performed with the smallest wind speed and air volume.

[0087] The present application realizes the automation and intelligent control of the ventilation system by real-time acquisition of images and dust parameters in the tunnel through the Internet of Things technology, dynamically adjusts the ventilation parameters according to the real-time data, avoids the poor ventilation effect or energy waste caused by fixed parameters in the traditional ventilation system, optimizes the ventilation parameters to ensure that the dust concentration in the tunnel is always within a safe range, reduces the risk of construction personnel exposed to harmful dust environment, dynamically controls the ventilation system to quickly respond to changes in the construction process, such as sudden increase of dust concentration after blasting operation, adjusts the ventilation strategy in time to ensure construction safety, intelligently controls the ventilation parameters to avoid unnecessary energy waste, and flexibly adjusts the ventilation parameters according to different tunnel construction conditions, which has strong adaptability and saves power.

[0088] Those skilled in the art will appreciate that embodiments of the present application can be readily used as a method, a system or a computer program product. Accordingly, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application can take the form of a computer program product on one or more computer-usable storage media (or computer- readable storage media) having computer-usable program code embodied in the medium. The medium may Figure 1 one or more functions specified in the flow or flows and / or blocks Figure 1 one or more functions specified in the flow or flows and / or blocks

[0089] It should be noted that the above-mentioned embodiments are only used to illustrate but not to limit the technical solutions of the present application. Although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the spirit and scope of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A tunnel construction ventilation control method based on the Internet of Things, characterized in that, The method comprises the following steps: Step S100, acquiring a tunnel face picture, matching a first ventilation parameter according to the tunnel face picture, simulating tunnel ventilation according to the first ventilation parameter, obtaining a tunnel flow field map, and obtaining an air flow region according to the tunnel flow field map; Step S200, detecting a dust parameter of the air flow region, and calculating a dust settling velocity of each air flow region according to a Stokes formula; Step S300, issuing a first control signal according to the dust settling velocity of each air flow region, performing first control on the first ventilation parameter according to the first control signal, obtaining a second ventilation parameter, and performing a first operation according to the gas parameter of each air flow region after the first control; Step S400, presetting a transition time point according to the dust concentration and the gas parameter after the first operation, and performing second control on the second ventilation parameter after the transition time point; The first ventilation parameter comprises air volume and air pressure; The air flow region comprises a jet flow region, an eddy flow region and a backflow region; The tunnel face picture is acquired, a tunnel shape database is called, and any standard tunnel face picture is acquired from the tunnel shape database. The tunnel shape database comprises standard tunnel shape names and corresponding standard tunnel face pictures. The standard tunnel shape names comprise straight-line tunnels, roadways and spiral-line tunnels. First characteristic quantities of the tunnel face picture are extracted, and second characteristic quantities of the standard tunnel face pictures are extracted. The first characteristic quantities and the second characteristic quantities are shape characteristic quantities. A first similarity between the first characteristic quantities and the second characteristic quantities is calculated by using a cosine similarity formula. A first value is set as a similarity threshold value. The first similarity and the first value are compared. When the first similarity is greater than or equal to the first value, a standard tunnel shape name corresponding to the second characteristic quantities is set as a current tunnel shape name. A ventilation database is called. The ventilation database comprises tunnel shape names, corresponding distances between air duct openings and working faces, corresponding air duct cross-sectional areas, corresponding distribution positions of air ducts in tunnels, corresponding air volumes and corresponding air pressures. The current tunnel shape name is input into the ventilation database, and the corresponding distances between the air duct openings and the working faces, the corresponding air duct cross-sectional areas, the corresponding distribution positions of the air ducts in the tunnels, the corresponding air volumes and the corresponding air pressures are obtained. The type of the air duct is selected according to the corresponding distances between the air duct openings and the working faces, the corresponding air duct cross-sectional areas and the corresponding distribution positions of the air ducts in the tunnels, and the layout of the air duct in the tunnel is set. The corresponding air volume and the corresponding air pressure are set as the first ventilation parameter.

2. The Internet of Things based tunneling ventilation control method as claimed in claim 1, wherein: Construction blasting is simulated according to the first ventilation parameter, and a tunnel flow field map is obtained. The air flow region is obtained according to the tunnel flow field map. The tunnel curvature radius, the tunnel length and the distance between the air duct opening and the tunnel face are input into the simulation software, the tunnel ventilation model is constructed, the tunnel flow field map is obtained by taking a second value as the air inlet velocity, the tunnel flow field map is divided into the air flow region according to the preset air flow region division knowledge spectrum map. 3.The Internet of Things based tunnel construction ventilation control method of claim 2, wherein: The preset air flow region division knowledge spectrum map comprises: The region in which the air flow direction is mainly along the air duct axis direction is set as the jet flow region. The area with the wind flow direction in a rotating state is set as a vortex area; The area with the first distance from the working face and the direction opposite to the wind flow direction of the jet flow area is set as a backflow area.

4. The Internet of Things based tunneling ventilation control method as claimed in claim 1, wherein: Detect dust parameters of the wind flow area through the sensor array of the Internet of Things front end, the dust parameters including dust density, air density, gravitational acceleration, air dynamic viscosity, dust particle diameter, dust specific gravity, and air specific gravity; Call the Stokes formula, input the dust parameters of the wind flow area into the Stokes formula, and calculate the dust settling velocity of the corresponding wind flow area. 5.The Internet of Things based tunnel construction ventilation control method of claim 4, wherein: Set the third value as the settling velocity threshold value; Obtain any wind flow area, obtain the settling velocity of each dust in the wind flow area, sort the settling velocity of each dust in the wind flow area in descending order, select the largest settling velocity, set the largest settling velocity as the critical velocity of the wind flow area, traverse each wind flow area, and set the corresponding critical velocity of each wind flow area; Compare the corresponding critical velocity of each wind flow area with the third value, when there is a critical velocity greater than the third value, send a first control signal, and when all critical velocities are less than or equal to the third value, do not send the first control signal; When the first control signal is sent, the first ventilation parameter is subjected to the first control, and the method of the first control includes: Take the fourth value as the change gradient of the air volume and the fifth value as the change gradient of the air pressure, continuously change the air volume according to the fourth value and continuously change the air pressure according to the fifth value, and make the air volume and the air pressure not exceed the maximum bearing air volume and the maximum bearing air pressure of the air pipe; Until all critical velocities are less than or equal to the third value, the first control is not performed.

6. The Internet of Things based tunneling ventilation control method as claimed in claim 5, wherein: Set the first ventilation parameter after the first control as the second ventilation parameter, obtain the gas parameters of each wind flow area after the first control, and obtain the concentration threshold range of each gas parameter according to the construction safety standard; The gas parameters include carbon monoxide volume concentration, carbon dioxide gas concentration, nitrogen oxide gas concentration, sulfurized gas volume concentration, and oxygen concentration, and the first operation is performed according to the gas parameters of each wind flow area after the first control; The first operation includes controlling the second ventilation parameter and not controlling the second ventilation parameter, when there is a gas parameter not distributed in the corresponding concentration threshold range, the first operation is set to control the second ventilation parameter, and when all gas parameters are distributed in the corresponding concentration threshold range, the first operation is set to not control the second ventilation parameter; When the first operation is to control the second ventilation parameter, take the seventh value as the air volume change gradient and the eighth value as the air pressure change gradient, continuously increase the air volume according to the seventh value and continuously increase the air pressure according to the eighth value, and make the air volume and the air pressure not exceed the maximum bearing air volume and the maximum bearing air pressure of the air pipe, until all gas parameters are distributed in the corresponding concentration threshold range, stop controlling the second ventilation parameter; When the first operation is not to control the second ventilation parameter, the second ventilation parameter is not controlled.

7. The Internet of Things based tunneling ventilation control method as claimed in claim 6, wherein: The dust concentration sequence and the gas parameter sequence are obtained by acquiring the dust concentration and the gas parameter after each interval time period after the first operation, the interval time period being the first time period; A first difference value of adjacent dust concentrations or adjacent gas concentrations is calculated, the adjacent indicating time sequence adjacent, a first ratio of the first difference value to a previous dust concentration in the adjacent dust concentrations is calculated, or a first ratio of the first difference value to a previous gas concentration in the adjacent gas concentrations is calculated, a ninth value is set as a change rate threshold, each first ratio is compared with the ninth value, when the first ratio is less than or equal to the ninth value, the corresponding dust concentration or gas concentration is retained, and when the first ratio is greater than the ninth value, the corresponding dust concentration or gas concentration is deleted; A time point corresponding to the earliest time sequence dust concentration or gas concentration is selected, the time point corresponding to the earliest time sequence dust concentration or gas concentration is set as a transition time point, and the transition time point is preset; The second ventilation parameter is second-regulated after the transition time point, the second regulation including continuously reducing the wind speed and continuously reducing the air volume, so that the dust concentration and the gas concentration are distributed in the standard dust concentration distribution range and the standard gas concentration distribution range, the smallest numerical value of the wind speed and the air volume is selected, and constant ventilation is performed at the smallest numerical value of the wind speed and the air volume.

8. A tunnel construction ventilation control system based on Internet of Things, the system is used for executing the tunnel construction ventilation control method based on Internet of Things as claimed in claim 1, characterized in that, The method comprises a division module, a calculation module and a regulation module; The division module is configured to acquire a tunnel face picture, match a first ventilation parameter according to the tunnel face picture, simulate tunnel ventilation according to the first ventilation parameter, obtain a tunnel flow field diagram, and obtain an air flow region according to the tunnel flow field diagram; The calculation module is configured to detect dust parameters of the air flow region, and calculate dust settling velocities of each air flow region according to a Stokes formula; The regulation module is configured to send a first regulation signal according to the dust settling velocities of each air flow region, perform first regulation on the first ventilation parameter according to the first regulation signal to obtain a second ventilation parameter, perform a first operation according to the dust concentration and the gas parameter after the first operation, preset a transition time point according to the dust concentration and the gas parameter after the first operation, and perform second regulation on the second ventilation parameter after the transition time point.

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