Local intelligent cooling method for high-temperature tunnel construction

Abstract

This invention provides a method for localized intelligent cooling during high-temperature tunnel construction, relating to the field of tunnel cooling. The method includes: an insulated air duct, nozzles, a host computer, and a variable frequency fan. The insulated air duct is installed on the sidewall inside the tunnel, with one end connected to the variable frequency fan and the other end connected to a flow meter to measure the ventilation volume inside the tunnel. Multiple nozzles are installed on the inner wall of the tunnel's top surface, each equipped with a temperature sensor. The nozzles are connected to the host computer via a programmable logic controller. This invention employs a coupled ventilation and cooling scheme, reducing localized high temperatures during tunnel construction and improving the working environment for workers.

Description

Technical Field

[0001] This invention relates to the field of tunnel cooling, and more particularly to a local intelligent cooling method for high-temperature tunnel construction. Background Technology

[0002] The steep terrain, significant tectonic activity, frequent geological disasters, fragile ecosystems, and harsh climate conditions of the plateau region pose multiple practical challenges to the construction of high-altitude tunnels. Furthermore, the Sichuan-Tibet Railway's two tunnels are located along high altitudes with low temperatures, and the extensive temperature distribution within the ultra-long tunnels results in significant temperature differences between the inside and outside of the tunnels. This presents numerous engineering challenges and practical difficulties during construction, including high construction costs, high safety risks, severe reduction in construction efficiency, and a lack of effective prevention and control measures. The high-temperature and adverse geological conditions of high-altitude tunnels have extremely adverse effects on tunnel construction and operation. The high-temperature, high-humidity, and low-oxygen working environment makes it impossible for personnel to perform normal construction work, easily leading to sudden increases in respiratory rate, dehydration, vomiting, dizziness, and hypoxic shock. Sudden bursts of hot water and steam can cause injury or even death to construction machinery and personnel, and the working efficiency and lifespan of mechanical equipment are also severely damaged in this environment. High ground temperatures also affect the stability of the surrounding rock, seriously impacting tunnel excavation. Additionally, in the high-temperature and hot-water immersion environment, explosives expand and melt, producing a pungent ammonium nitrate odor, causing significant harm to human health. Furthermore, detonating cords, detonators, and other detonating devices can only function normally within a certain temperature range. They may fail in high-temperature environments, leading to misfires and safety hazards. Currently, conventional cooling methods for high-temperature tunnel construction are simple and outdated, merely increasing fan power and employing multiple workers in shifts. This approach results in long construction periods, high costs, significant safety risks, and low cooling efficiency. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a method for localized intelligent cooling during high-temperature tunnel construction, specifically comprising: A local intelligent cooling system for high-temperature tunnel construction includes: an insulated air duct, nozzles, a host computer, and a variable frequency fan; The heat-insulating air duct is installed on the side wall inside the tunnel. One end of the heat-insulating air duct is connected to the variable frequency fan, and the other end of the heat-insulating air duct is connected to a flow meter, which is used to measure the ventilation volume inside the tunnel. Multiple nozzles are provided on the inner wall of the tunnel top surface. Each nozzle is equipped with a temperature sensor. The nozzles are connected to the host computer through a programmable logic controller.

[0004] Optionally, the temperature sensor, the variable frequency fan, and the flow meter are electrically connected to the host computer.

[0005] Optionally, the inner wall of the top surface of the tunnel is provided with m rows of nozzle assemblies, and the number of nozzles in each row of nozzle assemblies is n.

[0006] Optionally, the number of rows of the nozzle assembly m The calculation formula is formula (1): (1) m is the number of rows in the nozzle assembly; a The length of the tunnel; S is the effective spray area of ​​one of the nozzles.

[0007] Optionally, the formula for calculating the number n of the nozzles in each row of the nozzle assembly is formula (2): (2) n is the number of nozzles in each row of the nozzle assembly; b is the longest width of the cross-section of the tunnel where one of the nozzles is located; S is the effective spray area of ​​one of the nozzles.

[0008] Optionally, the variable frequency fan includes a first frequency, a second frequency, a third frequency, and a fourth frequency. When the variable frequency fan is at the first frequency, when the variable frequency fan is at the second frequency, when the variable frequency fan is at the third frequency, and when the variable frequency fan is at the fourth frequency, the power required by the variable frequency fan increases sequentially.

[0009] A method for localized intelligent cooling during high-temperature tunnel construction, applied to the aforementioned high-temperature tunnel construction localized intelligent cooling system, includes the following operating conditions: First operating condition: The variable frequency fan is operating at the first frequency; Second operating condition: The variable frequency fan is operating at the second frequency; Third operating condition: The variable frequency fan is operating at the third frequency; Fourth operating condition: The variable frequency fan is operating at the fourth frequency; The method includes the following steps: S1. All temperature sensors monitor the temperature inside the tunnel and transmit the monitored temperature signals to the host computer. S2. The host computer receives the temperature signal and summarizes the temperature values ​​transmitted by all temperature signals to obtain the average temperature. When the average temperature is less than or equal to 28°C, the host computer controls the variable frequency fan to continuously execute the first working condition to ventilate the tunnel. When the average temperature exceeds 28°C but is below 30°C, the host computer controls the variable frequency fan to execute the second working condition for 30 minutes to ventilate the tunnel. When the average temperature exceeds 30°C but is below 32°C, the host computer controls the variable frequency fan to execute the third working condition for 20 minutes to ventilate the tunnel. When the average temperature exceeds 32°C, the host computer controls the variable frequency fan to execute the fourth working condition for 15 minutes to ventilate the tunnel. S3. After ventilation for the specified time, all the temperature sensors monitor the temperature inside the tunnel and upload the monitored temperature signals to the host computer; S4. The host computer receives the temperature signal and summarizes the temperature values ​​transmitted by all temperature signals to obtain the average temperature. When the average temperature is less than or equal to 28°C, the host computer controls the variable frequency fan to continuously execute the first working condition to ventilate the tunnel. When the average temperature exceeds 28°C but is below 30°C, the host computer controls the variable frequency fan to execute the second working condition to ventilate the tunnel. At the same time, the host computer determines the specific location of the temperature sensor that transmits a temperature signal exceeding 28°C based on all temperature signals transmitted by the temperature sensor. The host computer then controls the programmable logic controller to open the nozzles at the locations where the temperature exceeds 28°C to perform spray cooling. When the average temperature exceeds 30°C but is below 32°C, the host computer controls the variable frequency fan to execute the third working condition to ventilate the tunnel; at the same time, the host computer determines the specific location of the temperature sensor transmitting a temperature signal exceeding 28°C based on all temperature signals transmitted by the temperature sensor, and the host computer controls the programmable logic controller to open the nozzles at the locations where the temperature exceeds 28°C to perform spray cooling. When the average temperature exceeds 32°C, the host computer controls the variable frequency fan to execute the fourth working condition to ventilate the tunnel; at the same time, the host computer determines the specific location of the temperature sensor that transmits a temperature signal exceeding 28°C based on all temperature signals transmitted by the temperature sensor, and the host computer controls the programmable logic controller to open the nozzles at the locations where the temperature exceeds 28°C to spray and cool down. S5. During the ventilation and cooling process and the spray cooling process, all temperature sensors monitor the temperature inside the tunnel and transmit the monitored temperature signals to the host computer; the host computer receives the temperature signals and summarizes the temperature values ​​transmitted by all temperature signals to obtain the average temperature. When the average temperature is less than or equal to 28°C, the host computer controls the variable frequency fan to continuously execute the first working condition to ventilate the tunnel; at the same time, the host computer controls the programmable logic controller to shut down all the nozzles. When the average temperature exceeds 28°C, the host computer controls the variable frequency fan to execute the corresponding operating condition according to each temperature range in S4. At the same time, the host computer controls the programmable logic controller to make the nozzles spray continuously until the average temperature drops below 28°C. When the average temperature drops below 28°C, the host computer controls the programmable logic controller to shut down all the nozzles. At the same time, the host computer controls the variable frequency fan to execute the first operating condition to continuously ventilate the tunnel.

[0010] Optionally, the host computer embeds an adaptive PID control method to control the switching operation of the variable frequency fan.

[0011] Optionally, the method includes ventilation verification, which includes the following steps: S101, the flow meter uploads the ventilation volume of the variable frequency fan when it performs the first operating condition, the ventilation volume of the variable frequency fan when it performs the second operating condition, the ventilation volume of the variable frequency fan when it performs the third operating condition, and the ventilation volume of the variable frequency fan when it performs the fourth operating condition to the host computer. S102. The host computer has a built-in CFD control equation calculation system with imposed initial conditions and boundary conditions. The ventilation volume detected by the flow meter is substituted into the CFD control equation with imposed initial conditions and boundary conditions to solve the problem and obtain the simulated temperature distribution in the tunnel. S103. Compare the simulated temperature distribution in the tunnel with the actual temperature in the tunnel monitored by all temperature sensors after ventilation for the specified time in S3. When the simulated temperature distribution is lower than the actual temperature, the ventilation effect in the tunnel is poor. When the simulated temperature distribution is greater than or equal to the actual temperature, the ventilation effect in the tunnel is good.

[0012] The above technical solution has at least the following advantages compared with the existing technology: This solution employs a coupled ventilation and cooling approach, combining ventilation and cooling with misting to reduce localized high temperatures during construction, improve the working environment for workers, and include a host computer control system that intelligently selects the cooling method based on the tunnel temperature, saving energy, reducing costs, and improving cooling efficiency. Misting can also reduce dust. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This invention provides a structural schematic diagram of a local intelligent cooling system for high-temperature tunnel construction. Figure 2 The diagram shows the arrangement of nozzles in a local intelligent cooling system for high-temperature tunnel construction provided by this invention. Figure 3 The flowchart of a local intelligent cooling method for high-temperature tunnel construction provided by the present invention.

[0015] Figure label: 1. Surrounding rock of high-altitude tunnels; 2. Nozzle; 3. Insulated air duct; 4. Variable frequency fan; 5. Tunnel; 6. Gas flow meter. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0017] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising,” “including,” or “including,” and similar terms mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or “connected,” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0018] It should be noted that the terms "up", "down", "left", "right", "front", and "back" used in this invention are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0019] like Figures 1-2 As shown, a local intelligent cooling system for high-temperature tunnel construction includes a host computer. A tunnel 5 is excavated within the surrounding rock 1 of a high-altitude tunnel. High temperatures are generated within the tunnel 5 during excavation. The tunnel 5 preferably has an arched cross-section. An insulated air duct 3 is installed on one side wall of the tunnel 5. A gas flow meter 6 is installed at one end of the insulated air duct 3 within the tunnel 5, and a variable frequency fan 4 is connected to the other end. The variable frequency fan 4 is existing technology and will not be described in detail here. The airflow of the variable frequency fan 4 at high frequencies is greater than that at low frequencies. The gas flow meter 6 is used to measure the ventilation volume within the tunnel 5, which is the same as the airflow of the variable frequency fan. The insulated air duct 3 is a flexible, pipe-like structure. The air blown by the variable frequency fan 4 is transmitted into the tunnel 5 through the insulated air duct 3. The variable frequency fan 4 is a forced-flow variable frequency fan. The function of the insulated air duct 3 is to prevent heat exchange between the forced-flow variable frequency fan 4 and the high-temperature gas in the tunnel 5 during the transmission of fresh, low-temperature air from outside the high-altitude tunnel.

[0020] The inner wall of the top surface of tunnel 5 is equipped with m rows of nozzle assemblies. Each row of nozzle assembly contains n nozzles 2, and each nozzle 2 is equipped with a temperature sensor. The nozzles 2 are connected to a host computer via a programmable logic controller. The temperature sensor, variable frequency fan 4, and gas flow meter 6 are electrically connected to the host computer.

[0021] The programmable logic controller is preferably an S7-200 SMART PLC, which can realize the automatic control of the valves of the nozzle assembly.

[0022] Number of rows in the nozzle assembly m The calculation formula is formula (1): (1) m is the number of rows in the nozzle assembly; a The length of tunnel 5;

[0023] S The effective spray area of ​​a nozzle 2 。

[0024] The number of rows (m) of the nozzle assembly is mainly determined by the length of tunnel 5.

[0025] The formula for calculating the number n of nozzles 2 in each row of nozzle assembly is formula (2): (2) n is the number of nozzles 2 in each row of nozzle assemblies; b is the longest width of the cross-section of the tunnel 5 where a nozzle 2 is located in each row; S represents the effective spray area of ​​a nozzle 2.

[0026] The number n of nozzles 2 in each row of nozzle assemblies is mainly determined by the maximum width of the cross-section of the tunnel 5, thus forming a full-section cooling spray.

[0027] In this scheme, the variable frequency fan 4 has four frequencies: the first frequency, the second frequency, the third frequency, and the fourth frequency. When the variable frequency fan 4 is at the first frequency, when the variable frequency fan 4 is at the second frequency, when the variable frequency fan 4 is at the third frequency, and when the variable frequency fan 4 is at the fourth frequency, the power required by the variable frequency fan 4 increases sequentially.

[0028] This solution employs a coupled ventilation and cooling approach, combining ventilation and cooling with misting to reduce localized high temperatures during construction, improve the working environment for workers, and include a host computer control system that intelligently selects the cooling method based on the tunnel temperature, saving energy, reducing costs, and improving cooling efficiency. Misting can also reduce dust.

[0029] like Figure 3 As shown, a local intelligent cooling method for high-temperature tunnel construction is disclosed, the method including the following working conditions: First operating condition: Variable frequency fan 4 is operating at the first frequency; Second operating condition: Variable frequency fan 4 is operating at the second frequency; Third operating condition: Variable frequency fan 4 is operating at the third frequency; Fourth operating condition: Variable frequency fan 4 is operating at the fourth frequency; The operating frequency of variable frequency fan 4 is calculated by the host computer using a segmented algorithm.

[0030] The method includes the following steps: S1. The host computer controls the opening of the temperature sensor on the nozzle 2. All temperature sensors monitor the temperature inside the tunnel 5 and transmit the monitored temperature signal to the host computer. S2. The host computer receives the temperature signal and summarizes the temperature values ​​transmitted by all temperature signals to obtain the average temperature. When the average temperature is less than or equal to 28℃, the host computer controls the variable frequency fan 4 to continuously execute the first working condition to ventilate the tunnel 5. When the average temperature exceeds 28℃ but is below 30℃, the host computer controls the variable frequency fan 4 to execute the second working condition for 30 minutes to ventilate the tunnel 5. When the average temperature exceeds 30℃ but is below 32℃, the host computer controls the variable frequency fan 4 to execute the third working condition for 20 minutes to ventilate the tunnel 5. When the average temperature exceeds 32℃, the host computer controls the variable frequency fan 4 to execute the fourth working condition for 15 minutes to ventilate the tunnel 5. S3. After ventilation for the specified time, the host computer controls all temperature sensors to monitor the temperature inside tunnel 5 and uploads the monitored temperature signals to the host computer. S4. The host computer receives the temperature signal and summarizes the temperature values ​​transmitted by all temperature signals to obtain the average temperature. When the average temperature is less than or equal to 28℃, the host computer controls the variable frequency fan 4 to continuously execute the first working condition to ventilate the tunnel 5. When the average temperature exceeds 28℃ but is below 30℃, the host computer controls the variable frequency fan 4 to execute the second working condition to ventilate the tunnel 5. At the same time, the host computer determines the specific location of the temperature sensor that transmits a temperature signal exceeding 28℃ based on all temperature signals transmitted by the temperature sensor. The host computer then controls the programmable logic controller to open the nozzle 2 at the location where the temperature exceeds 28℃ to spray and cool down. When the average temperature exceeds 30℃ but is below 32℃, the host computer controls the variable frequency fan 4 to execute the third working condition to ventilate the tunnel 5. At the same time, the host computer determines the specific location of the temperature sensor that transmits a temperature signal exceeding 28℃ based on all temperature signals transmitted by the temperature sensor. The host computer then controls the programmable logic controller to open the nozzle 2 at the location where the temperature exceeds 28℃ to spray and cool down. When the average temperature exceeds 32℃, the host computer controls the variable frequency fan 4 to execute the fourth working condition to ventilate the tunnel 5. At the same time, the host computer determines the specific location of the temperature sensor that transmits a temperature signal exceeding 28℃ based on all temperature signals transmitted by the temperature sensor. The host computer then controls the programmable logic controller to open the nozzle 2 at the location where the temperature exceeds 28℃ to spray and cool down. S5. During the ventilation and cooling process and the spray cooling process, the host computer controls all temperature sensors to monitor the temperature inside tunnel 5 and transmits the monitored temperature signals to the host computer. The host computer receives the temperature signals and summarizes the temperature values ​​transmitted by all temperature signals to obtain the average temperature. When the average temperature is less than or equal to 28℃, the host computer controls the variable frequency fan 4 to continuously execute the first working condition to ventilate the tunnel 5; at the same time, the host computer controls the programmable logic controller to shut down all nozzles 2. When the average temperature exceeds 28℃, the host computer controls the variable frequency fan to execute the corresponding working condition according to each temperature range in S4. At the same time, the host computer controls the programmable logic controller to make the nozzle 2 continuously spray at the position where the temperature exceeds 28℃ until the average temperature drops below 28℃. When the average temperature drops below 28℃, the host computer controls the programmable logic controller to shut down all nozzles 2. At the same time, the host computer controls the variable frequency fan 4 to execute the first working condition to continuously ventilate the tunnel 5 and keep the temperature in the tunnel 5 below 28℃.

[0031] In this embodiment, the host computer uses an embedded adaptive PID control method to control the switching of the operating conditions of the variable frequency fan 4. The adaptive PID control method is existing technology and will not be described in detail here.

[0032] A local intelligent cooling method for high-temperature tunnel construction includes ventilation verification, which includes the following steps: S101, the gas flow meter 6 uploads the ventilation volume of the variable frequency fan 4 when it performs the first working condition, the ventilation volume of the variable frequency fan 4 when it performs the second working condition, the ventilation volume of the variable frequency fan 4 when it performs the third working condition, and the ventilation volume of the variable frequency fan 4 when it performs the fourth working condition to the host computer. S102. The host computer has a built-in CFD control equation calculation system with imposed initial and boundary conditions. This is existing technology and will not be described in detail here. The ventilation volume detected by gas flow meter 6 is substituted into the CFD control equation with imposed initial and boundary conditions to solve, thereby obtaining the simulated temperature distribution in tunnel 5. The step of substituting the ventilation volume detected by gas flow meter 6 into the CFD control equation with imposed initial and boundary conditions is completed by importing the profile file into Fluent. This is existing technology and will not be described in detail here.

[0033] S103. Compare the simulated temperature distribution in tunnel 5 with the actual temperature in tunnel 5 monitored by all temperature sensors after ventilation for the specified time in S3. When the simulated temperature distribution is lower than the actual temperature, the ventilation effect in tunnel 5 is poor. When the simulated temperature distribution is greater than or equal to the actual temperature, the ventilation effect in tunnel 5 is good.

[0034] In this embodiment, a temperature sensor is used to detect high-temperature areas. The host computer determines the local cooling requirement based on a thermodynamic evaluation model. The calculation method for the ventilation volume of the variable frequency fan 4 under the first operating condition refers to the air volume calculation method in the Coal Industry Design Manual, which is existing technology and will not be described in detail here. The host computer controls ventilation cooling and mist cooling to keep the temperature inside tunnel 5 below 28°C. If the temperature inside tunnel 5 exceeds 28°C, high-power ventilation is performed, and if the temperature still remains above 28°C, the host computer controls the mist cooling to be activated while maintaining high-power ventilation. Ventilation cooling and mist cooling are performed simultaneously until the temperature inside tunnel 5 drops below 28°C.

[0035] This solution employs a coupled ventilation and cooling approach, combining ventilation and cooling with misting to reduce localized high temperatures during construction, improve the working environment for workers, and include a host computer control system that intelligently selects the cooling method based on the tunnel temperature, saving energy, reducing costs, and improving cooling efficiency. Misting can also reduce dust.

[0036] The following points need to be explained: (1) The accompanying drawings of the embodiments of the present invention only involve the structures involved in the embodiments of the present invention. Other structures can refer to the general design.

[0037] (2) For clarity, the thickness of layers or regions is enlarged or reduced in the drawings used to describe embodiments of the invention, i.e., these drawings are not drawn to scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being “above” or “below” another element, the element may be “directly” located “above” or “below” the other element or there may be intermediate elements.

[0038] (3) Where there is no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0039] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for localized intelligent cooling during high-temperature tunnel construction, characterized in that, An intelligent local cooling system for high-temperature tunnel construction is provided, comprising an insulated air duct, nozzles, a host computer, and a variable frequency fan. The heat-insulating air duct is installed on the side wall inside the tunnel. One end of the heat-insulating air duct is connected to the variable frequency fan, and the other end of the heat-insulating air duct is connected to a flow meter, which is used to measure the ventilation volume inside the tunnel. Multiple nozzles are provided on the inner wall of the tunnel top surface. Each nozzle is equipped with a temperature sensor. The nozzles are connected to the host computer through a programmable logic controller. The method includes the following operating conditions: First operating condition: The variable frequency fan is operating at the first frequency; Second operating condition: The variable frequency fan is operating at the second frequency; Third operating condition: The variable frequency fan is operating at the third frequency; Fourth operating condition: The variable frequency fan is operating at the fourth frequency; The method includes the following steps: S1. All temperature sensors monitor the temperature inside the tunnel and transmit the monitored temperature signals to the host computer. S2. The host computer receives the temperature signal and summarizes the temperature values ​​transmitted by all temperature signals to obtain the average temperature. When the average temperature is less than or equal to 28°C, the host computer controls the variable frequency fan to continuously execute the first working condition to ventilate the tunnel. When the average temperature exceeds 28°C but is below 30°C, the host computer controls the variable frequency fan to execute the second working condition for 30 minutes to ventilate the tunnel. When the average temperature exceeds 30°C but is below 32°C, the host computer controls the variable frequency fan to execute the third working condition for 20 minutes to ventilate the tunnel. When the average temperature exceeds 32°C, the host computer controls the variable frequency fan to execute the fourth working condition for 15 minutes to ventilate the tunnel. S3. After ventilation for the specified time, all the temperature sensors monitor the temperature inside the tunnel and upload the monitored temperature signals to the host computer; S4. The host computer receives the temperature signal and summarizes the temperature values ​​transmitted by all temperature signals to obtain the average temperature. When the average temperature is less than or equal to 28°C, the host computer controls the variable frequency fan to continuously execute the first working condition to ventilate the tunnel. When the average temperature exceeds 28°C but is below 30°C, the host computer controls the variable frequency fan to execute the second working condition to ventilate the tunnel. At the same time, the host computer determines the specific location of the temperature sensor that transmits a temperature signal exceeding 28°C based on all temperature signals transmitted by the temperature sensor. The host computer then controls the programmable logic controller to open the nozzles at the locations where the temperature exceeds 28°C to perform spray cooling. When the average temperature exceeds 30°C but is below 32°C, the host computer controls the variable frequency fan to execute the third working condition to ventilate the tunnel; at the same time, the host computer determines the specific location of the temperature sensor transmitting a temperature signal exceeding 28°C based on all temperature signals transmitted by the temperature sensor, and the host computer controls the programmable logic controller to open the nozzles at the locations where the temperature exceeds 28°C to perform spray cooling. When the average temperature exceeds 32°C, the host computer controls the variable frequency fan to execute the fourth working condition to ventilate the tunnel; at the same time, the host computer determines the specific location of the temperature sensor that transmits a temperature signal exceeding 28°C based on all temperature signals transmitted by the temperature sensor, and the host computer controls the programmable logic controller to open the nozzles at the locations where the temperature exceeds 28°C to spray and cool down. S5. During the ventilation and cooling process and the spray cooling process, all temperature sensors monitor the temperature inside the tunnel and transmit the monitored temperature signals to the host computer; the host computer receives the temperature signals and summarizes the temperature values ​​transmitted by all temperature signals to obtain the average temperature. When the average temperature is less than or equal to 28°C, the host computer controls the variable frequency fan to continuously execute the first working condition to ventilate the tunnel; at the same time, the host computer controls the programmable logic controller to shut down all the nozzles. When the average temperature exceeds 28°C, the host computer controls the variable frequency fan to execute the corresponding working condition according to each temperature range in S4. At the same time, the host computer controls the programmable logic controller to make the nozzles spray continuously until the average temperature drops below 28°C. When the average temperature drops below 28°C, the host computer controls the programmable logic controller to shut down all the nozzles. At the same time, the host computer controls the variable frequency fan to execute the first working condition to continuously ventilate the tunnel. The tunnel has m rows of nozzle assemblies on its top inner wall, and each row of nozzle assemblies contains n nozzles. Number of rows of the nozzle assembly m The calculation formula is formula (1): （1） m is the number of rows in the nozzle assembly; a The length of the tunnel; S is the effective spray area of ​​one of the nozzles; The formula for calculating the number n of nozzles in each row of nozzle assemblies is formula (2): （2） n is the number of nozzles in each row of the nozzle assembly; b is the longest width of the cross-section of the tunnel where one of the nozzles is located; S is the effective spray area of ​​one of the nozzles; The variable frequency fan includes a first frequency, a second frequency, a third frequency, and a fourth frequency. When the variable frequency fan is at the first frequency, when the variable frequency fan is at the second frequency, when the variable frequency fan is at the third frequency, and when the variable frequency fan is at the fourth frequency, the power required by the variable frequency fan increases sequentially.

2. The method for local intelligent cooling in high-temperature tunnel construction according to claim 1, characterized in that, The host computer uses an embedded adaptive PID control method to control the switching operation of the variable frequency fan.

3. The method for local intelligent cooling in high-temperature tunnel construction according to claim 1, characterized in that, The method includes ventilation verification, which includes the following steps: S101, the flow meter uploads the ventilation volume of the variable frequency fan when it performs the first operating condition, the ventilation volume of the variable frequency fan when it performs the second operating condition, the ventilation volume of the variable frequency fan when it performs the third operating condition, and the ventilation volume of the variable frequency fan when it performs the fourth operating condition to the host computer. S102. The host computer has a built-in CFD control equation calculation system with imposed initial conditions and boundary conditions. The ventilation volume detected by the flow meter is substituted into the CFD control equation with imposed initial conditions and boundary conditions to solve the problem and obtain the simulated temperature distribution in the tunnel. S103. Compare the simulated temperature distribution in the tunnel with the actual temperature in the tunnel monitored by all temperature sensors after ventilation for the specified time in S3. When the simulated temperature distribution is lower than the actual temperature, the ventilation effect in the tunnel is poor. When the simulated temperature distribution is greater than or equal to the actual temperature, the ventilation effect in the tunnel is good.

4. The method for local intelligent cooling in high-temperature tunnel construction according to claim 1, characterized in that, The temperature sensor, the variable frequency fan, and the flow meter are electrically connected to the host computer.

Images