Ventilation roadbed intelligent control system and method for annual cold energy supply closed-loop regulation

Abstract

The present application relates to the technical field of subgrade ventilation control, and specifically discloses a kind of ventilation subgrade intelligent control system and method of annual cold supply closed-loop regulation and control, including the synergistic optimization of cold quantity total accounting, unit cold distribution scheme and dynamic compensation mechanism, the present application establishes annual cold demand model by fusing permafrost zone temperature multi-year monitoring curve and heat capacity parameter, annual cold is decomposed into unit component, and weight distribution strategy is dynamically adjusted according to air temperature fluctuation, and cold supply is preferentially improved in high temperature unit to balance thermal disturbance. Through intermittent dynamic ventilation mode, the heat exchange demand of permafrost layer is accurately matched, and the cross-unit adjustment of cold input deviation is combined with the account settlement compensation rule, which can effectively inhibit thawing and frost heaving deformation, and is suitable for permafrost subgrade engineering of transportation infrastructure in alpine regions, with the advantages of self-adaptive regulation and long-term stability.

Description

Technical Field

[0001] This invention relates to the field of roadbed ventilation control technology, and in particular to an intelligent control system and method for roadbed ventilation with closed-loop regulation of annual cooling supply. Background Technology

[0002] Roads traversing large areas of permafrost need to withstand extreme environmental conditions. For example, the heat absorption of asphalt pavement can accelerate the degradation of the underlying permafrost, leading to uneven settlement of the roadbed and affecting road smoothness. To prevent and manage road defects in permafrost regions, optimizations have been made to the roadbed structure and construction based on factors influencing heat exchange between the permafrost roadbed and the external environment, the heat transfer process of permafrost under multi-field coupling, a quantitative calculation model of heat budget for permafrost roadbeds, and the response mechanism of underlying permafrost to thermal disturbances in highway engineering.

[0003] Traditional foundation treatment technologies have significant limitations in addressing permafrost issues: passive ventilation systems are constrained by natural wind conditions, resulting in drastic fluctuations in cooling efficiency and even reverse heat conduction under extreme conditions; gravel slope protection structures suffer from reduced heat dissipation due to sediment deposition, leading to a significant decrease in engineering durability after long-term use; while active heat pipe technology achieves active temperature control through working fluid circulation, it still faces challenges such as the risk of working fluid leakage and high maintenance costs, and its temperature control precision is insufficient; and while active mechanical ventilation solutions can improve cooling capacity, they lack a cold energy unit distribution strategy, cannot specifically compensate for thermal erosion during the spring thaw, have insufficient dynamic adjustment capabilities, and blindly increasing ventilation volume can easily disrupt the thermal balance of permafrost, inducing local frost heave deformation. Summary of the Invention

[0004] To overcome the problems of fluctuating cooling efficiency and insufficient temperature control precision of various ventilation devices in existing frozen soil roadbeds, this invention provides an intelligent control system and method for ventilation roadbeds with closed-loop control of annual cooling supply.

[0005] In a first aspect, the present invention provides an intelligent control method for a ventilated roadbed with closed-loop control of annual cooling supply, wherein the ventilated roadbed is provided with an air inlet and an air outlet that allow airflow, and a fan for air supply; the method includes:

[0006] S1. Determine the annual cooling capacity based on the target roadbed, and decompose the annual cooling capacity into unit components and corresponding unit ventilation periods according to the historical temperature data of the target roadbed.

[0007] S2. Obtain the temperature change, water vapor mass change, and air flow rate at the air inlet and outlet, and determine the actual input cooling capacity based on the temperature change, water vapor mass change, and air flow rate.

[0008] S3. Based on the current unit ventilation period, obtain the cumulative actual input cooling capacity and cumulative unit cooling capacity of the unit ventilation periods that have been completed, and obtain the cooling capacity matching degree based on the cumulative actual input cooling capacity and cumulative unit cooling capacity;

[0009] S4. Adjust the frequency of the fan during the next unit ventilation period according to the cooling capacity matching degree;

[0010] S5. Repeat S2 to S4 until the actual annual cooling input is equal to the annual cooling input.

[0011] During the ventilation period of the first unit, the frequency of the fan is set based on predetermined conditions.

[0012] Depending on a specific implementation location, in the above-mentioned intelligent control method, S1 specifically includes:

[0013] The number of ventilation periods for each unit is preset, and the historical temperature data of each unit is divided according to the number of ventilation periods for each unit.

[0014] The unit component is determined based on the proportion of the unit's historical temperature data corresponding to the ventilation period to the historical annual temperature data.

[0015] Depending on the specific implementation location, in the above-mentioned intelligent control method, the cooling capacity matching degree is used to indicate whether the actual input cooling capacity increases, decreases, or remains unchanged during the next unit ventilation period.

[0016] Depending on a specific implementation location, in the above-mentioned intelligent control method, step S4 specifically includes:

[0017] The fan frequency control coefficient is determined based on the cooling capacity matching degree, using the following formula:

[0018] ,

[0019] in, η represents the fan frequency control coefficient, and η represents the cooling capacity matching degree.

[0020] The frequency of the fan is controlled according to the aforementioned fan frequency control coefficient, and the formula is as follows:

[0021] ,

[0022] in, This indicates the fundamental frequency of the wind turbine. f fan This indicates the adjusted frequency of the wind turbine.

[0023] According to a specific implementation location, in the above-mentioned intelligent control method, the unit component includes 36 units, and the corresponding unit ventilation period is 36 segments.

[0024] Depending on the specific implementation location, the above-mentioned intelligent control method further includes:

[0025] When the temperature difference between the air temperature and the ground temperature exceeds a predetermined threshold, the fan is controlled to start based on predetermined conditions.

[0026] Secondly, the present invention provides an intelligent control system for closed-loop regulation of annual cooling supply of ventilation roadbed, wherein the ventilation roadbed is provided with air inlets and outlets that allow airflow to pass through, as well as a fan for air supply, and the system further includes a ventilation module, a wind speed monitoring module, a temperature monitoring module and a central control module.

[0027] The ventilation module includes an air inlet pipe, an air outlet pipe, and branch pipes. The branch pipes are horizontally spaced to connect the air inlet pipe and the air outlet pipe. The middle part of the air inlet pipe is connected to the air inlet. The air outlet is symmetrically arranged at the edge of the ventilation roadbed, and the air outlet pipe is correspondingly arranged, with one end connected to the air outlet and the other end connected to the air inlet pipe through the branch pipe.

[0028] The wind speed monitoring module is used to monitor the change in water vapor mass at the air inlet and air outlet.

[0029] The temperature monitoring module is used to monitor the temperature changes at the air inlet and outlet, as well as the ground temperature.

[0030] The central control module is used to control the frequency of the fan by employing a closed-loop control method for annual cooling supply as described above.

[0031] According to a specific implementation, in the above-mentioned intelligent control system, the ventilated roadbed includes, from bottom to top, a gravelly clay layer, a silty clay layer, an active layer, a natural surface, a roadbed fill layer, a semi-rigid base layer, and an asphalt pavement layer, and the ventilation module is located above the natural surface and below the roadbed fill layer.

[0032] According to one specific implementation, in the above-mentioned intelligent control system, the temperature monitoring module is located below the natural ground surface, and the temperature monitoring module includes a temperature sensor located at the air inlet, a temperature sensor located at the air outlet, and a temperature sensor located in the middle of the ventilation module. Attached Figure Description

[0033] Figure 1 A schematic diagram of the structure of a closed-loop control system for annual cooling supply of a ventilated roadbed provided in an embodiment of the present invention;

[0034] Figure 2 A partial structural schematic diagram of a closed-loop control system for annual cooling supply of a ventilated roadbed provided in an embodiment of the present invention;

[0035] Figure 3 This is a top view of the ventilation module provided in an embodiment of the present invention;

[0036] Figure 4 A flowchart illustrating an intelligent control method for closed-loop regulation of annual cooling supply for ventilated roadbeds, provided in an embodiment of the present invention.

[0037] Figure 5 A flowchart illustrating an intelligent control method provided in another embodiment of the present invention;

[0038] Figure 6 This is a comparison diagram of the control of the ventilation roadbed provided in an embodiment of the present invention.

[0039] The diagram is marked as follows:

[0040] 1-Gravelly clay layer, 2-Silty clay layer, 3-Active layer, 4-Subgrade fill layer, 5-Semi-rigid base layer, 6-Asphalt pavement layer, 7-Ventilation module, 71-Inlet pipe, 72-Branch pipe, 731-Outlet pipe, 732-Outlet pipe, 8-Shoulder, 9-Slope protection, 10-Temperature sensor, 11-Wind speed monitoring module, 12-Frozen soil upper limit, 13-Natural surface, 14-Fan, 15-Central control module, 16-PVC pipe. Detailed Implementation

[0041] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0042] Unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of the present invention is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0043] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," and "parallel" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, or parallel, but rather that it can be slightly tilted or have a deviation. For example, "horizontal" merely means that its direction is more horizontal relative to "vertical," not that the structure must be completely horizontal, but that it can be slightly tilted. Alternatively, it can be simplified to mean that the corresponding device / component / element, when set in a "horizontal," "vertical," "suspended," or "parallel" direction, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the present invention.

[0044] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0045] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as 2, 3, 4, 5, 6, 7, 8, or 9, and can even exceed nine.

[0046] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to common connection methods in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0047] Current mainstream ventilation systems in ventilated roadbeds include U-shaped or inverted L-shaped ventilation ducts based on natural convection. However, these systems are highly dependent on meteorological conditions, and their cooling capacity fluctuates significantly with changes in ambient temperature. In mild seasons, the airflow temperature inside the ducts is higher than that of the frozen soil, exacerbating reverse heat exchange. While artificially pressurized forced ventilation strategies are effective in the short term, they cannot achieve precise control. Excessive air supply not only wastes energy but also causes localized ultra-low temperature crystallization and expansion due to the imbalance in the spatial and temporal distribution of cooling capacity, further worsening roadbed deformation problems.

[0048] Based on this, this invention provides an intelligent ventilation control system and method for frozen soil subgrade with closed-loop regulation of annual cooling supply. By adding a ventilation system to the frozen soil subgrade and constructing a collaborative optimization system of "annual cooling supply ledger + unit cooling supply allocation + dynamic fan control," a leapfrog innovation in temperature control and dehumidification technology for frozen soil subgrades is achieved. This method overcomes the limitation of traditional active mechanical ventilation schemes lacking a unit cooling supply allocation strategy. It establishes an annual cooling demand model by integrating multi-year temperature monitoring curves and heat capacity parameters of the frozen soil region. Based on the principle of frozen soil thermodynamic balance, the annual cooling supply is decomposed into unit components. The weight allocation strategy is dynamically adjusted according to temperature fluctuations, prioritizing increased cooling supply in high-temperature units to balance thermal disturbances. The cooling input within each unit is calculated using feedback data from temperature monitoring modules and wind speed and volume monitoring modules.

[0049] For details, please refer to Figure 1 and Figure 2 The diagram shows a structural schematic of an intelligent control system for closed-loop regulation of annual cooling supply provided by an embodiment of the present invention. The ventilation roadbed is provided with an air inlet and an air outlet that allow airflow, as well as a fan 14 for supplying air. The system includes a ventilation module 7, a wind speed monitoring module 11, a temperature monitoring module, and a central control module 15.

[0050] Further, please refer to Figure 3 The diagram illustrates the structure of a ventilation module 7 provided in an embodiment of the present invention. The ventilation module 7 includes an air inlet pipe 71, an air outlet pipe 731, and branch pipes 72. The branch pipes 72 are laterally spaced between the air inlet pipe 71 and the air outlet pipe 731. The middle portion of the air inlet pipe 71 is connected to the air inlet. The air outlets are symmetrically arranged at the edges of the ventilation roadbed, and the air outlet pipes 731 are correspondingly arranged, with one end connected to the air outlet and the other end connected to the air inlet pipe 71 via the branch pipes 72. The wind speed monitoring module 11 is used to monitor the airflow at the air inlet and air outlet. The temperature monitoring module is used to monitor the temperature and humidity changes at the air inlet and air outlet, as well as the ground temperature.

[0051] The ventilated roadbed includes, from bottom to top, a gravelly clay layer 1, a silty clay layer 2, an active layer 3, a natural surface 13, a roadbed fill layer 4, a semi-rigid base layer 5, and an asphalt pavement layer 6. The ventilation module 7 is located above the natural surface 13 and below the roadbed fill layer 4.

[0052] Specifically, a ventilation module 7 (a two-wing symmetrical ventilation pipe) is installed between the active layer 3 and the roadbed fill layer 4. The two-wing symmetrical ventilation pipe is a semi-rigid, composite material braided circular pipe. Temperature sensors 10 in the temperature detection module are horizontally arranged in the PVC pipe 16 below the two-wing symmetrical ventilation pipe in the active layer 3. In this embodiment, the temperature sensor 10 is a PT100 temperature sensor 10, which, from right to left, is embedded below the inlet, middle, and outlet sections of the two-wing symmetrical ventilation pipe. A wind speed detection module is arranged in the air inlet and outlet. In this embodiment, the wind speed monitoring module 11 is a hot-wire anemometer, used to calculate the heat carried away by moisture evaporation based on the wind speed difference between the inlet and outlet. A fan 14 and a central control module 15 are arranged in the air inlet. In this embodiment, the fan 14 is a variable frequency fan 14, and the central control module 15 is a PLC controller. In the intelligent control system of the present invention, the two-wing symmetrical ventilation pipes, the fan 14 and the central control module 15 are active defense structures. The structure of the present invention comprehensively adopts active defense measures, which can effectively prevent roadbed disasters in the cold season and significantly improve the freeze-thaw stability of the roadbed structure in the permafrost region.

[0053] Furthermore, the ventilation module 7 adopts a primary and secondary branch pipe network structure: ten transverse branch pipes 72 with an inner diameter of approximately 100mm and a wall thickness of approximately 6mm are set in the horizontal cross-section, and three longitudinal main pipes are arranged along the roadbed to form a crisscrossing three-dimensional pipe network. The branch pipes 72 are evenly distributed inside the roadbed at a spacing of 2m. This design parameter refers to the cooling radius theory of ventilation pipes, which ensures that the heat-affected zones of adjacent branch pipes 72 overlap and covers each other, and avoids wind speed attenuation due to insufficient pipe spacing. The key nodes of the system use tee joints connecting the longitudinal and transverse pipes to connect the pipe network, and a closed circulation system is constructed by external plugs on the longitudinal pipes. The air inlet and outlet are embedded 80.8m into the left and right road shoulders, respectively. The built-in variable frequency fan 14 and PLC controller can adjust the air volume in real time according to the feedback of the temperature control switch to achieve low-energy forced ventilation. It is worth noting that the design continues the engineering concept of coordinating the "chimney effect" with active cooling. While ensuring a constant total annual cooling input, the density of the pipeline network can be dynamically adjusted according to the type of permafrost, the width of the roadbed, and the climate characteristics.

[0054] Specifically, the central control module (15) is used to control the frequency of the fan by employing a closed-loop intelligent control method for annual cooling supply. For example, the central control module (15) may be a central processing unit (CPU) or a microcontroller (MCU).

[0055] The central control module (15) may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0056] The above-mentioned intelligent control method will be further introduced and explained below with reference to specific implementation methods.

[0057] Please refer to Figure 4 The diagram illustrates a flowchart of an intelligent control method for closed-loop regulation of annual cooling supply for ventilated roadbeds, provided by an embodiment of the present invention. The method includes:

[0058] S1. Determine the annual cooling capacity based on the target roadbed, and decompose the annual cooling capacity into unit components and corresponding unit ventilation periods according to the historical temperature data of the target roadbed.

[0059] S2. Obtain the temperature change, water vapor mass change, and air flow rate at the air inlet and outlet, and determine the actual input cooling capacity based on the temperature change, water vapor mass change, and air flow rate.

[0060] S3. Based on the current unit ventilation period, obtain the cumulative actual input cooling capacity and cumulative unit cooling capacity of the unit ventilation periods that have been completed, and obtain the cooling capacity matching degree based on the cumulative actual input cooling capacity and cumulative unit cooling capacity;

[0061] S4. Adjust the frequency of fan 14 in the next unit ventilation period according to the cooling capacity matching degree;

[0062] S5. Repeat S2 to S4 until the actual annual cooling input is equal to the annual cooling input.

[0063] During the ventilation period of the first unit, the frequency of fan 14 is set based on predetermined conditions.

[0064] Specifically, this invention establishes a benchmark model for annual cooling input using short-term units. Based on the principle of thermodynamic balance, it performs three-dimensional spatial gradient calculation of roadbed heat flux and employs a unit-based cooling input accounting algorithm for refined accounting, decomposing the annual cooling demand into 36 unit benchmark values. Simultaneously, it integrates wind turbines with a wind speed monitoring module to construct a fluid dynamics parameter matrix, establishing a nonlinear coupled adjustment model of wind turbine speed and valve opening. A feedforward-feedback composite control algorithm is used to dynamically optimize cooling input transfer efficiency. When the actual cooling input of a unit is lower than the benchmark value, a cooling input compensation mechanism is automatically triggered—accumulating the difference to the next unit. Through iterative compensation unit by unit, the total annual cooling input remains constant, achieving optimal cooling input transfer efficiency.

[0065] In one possible implementation, as described in S1 above, during the construction of new roads in permafrost areas, a permafrost roadbed ventilation system is installed during the roadbed construction phase. A real-time monitoring system for the permafrost roadbed, including but not limited to temperature monitoring systems and wind speed and volume monitoring systems, is installed simultaneously to provide real-time thermal state information of the permafrost roadbed. Further, thermodynamic parameters are input to calibrate the central control module and test the power regulation response of the fans. PI algorithm debugging is performed. An annual cooling demand model is established by integrating multi-year temperature monitoring curves and heat capacity parameters of the permafrost area. Based on the cooling demand model and the thermodynamic balance principle of permafrost, the annual cooling capacity is decomposed into unit components.

[0066] Specifically, the number of ventilation periods for each unit is preset, and the historical temperature data of each unit is divided according to the number of ventilation periods for each unit.

[0067] The unit component is determined based on the proportion of historical temperature data corresponding to each unit's ventilation period to the historical annual temperature data; the formula for calculating the unit component is:

[0068] ,

[0069] in, This represents the annual cooling capacity, and n represents the number of ventilation periods for the unit. The function representing the temperature monitoring curve during the i-th ventilation period. This indicates the statistical period time range for this ventilation period. This represents the unit component during the ventilation period of the i-th unit.

[0070] Furthermore, as described in S2 above, based on the data fed back by the temperature monitoring module and the wind speed monitoring module 11, the dynamic calculation of the cooling capacity input to the fan within the unit is realized. Specifically, the formula for calculating the actual cooling capacity input is:

[0071] ,

[0072] Where m represents air mass flow rate, the unit is kd / m 3 , This indicates the enthalpy difference between the air inlet and outlet, expressed in kJ / kg.

[0073] The formula for calculating the air mass flow rate is:

[0074] ,

[0075] in, This indicates air density, expressed in kg / m³. 3 L represents ventilation volumetric flow rate, in cubic meters per second (m³). 3 / s.

[0076] The formula for calculating the enthalpy difference is:

[0077] ,

[0078] in, This represents the specific heat capacity at constant pressure, expressed in kJ / (kg·℃). This indicates the temperature change at the air inlet and outlet. This represents the change in mass of water vapor per unit mass of dry air, expressed in kg / kg. ai .

[0079] Furthermore, as described in S3 above, after the unit ventilation period ends, the actual total cooling capacity of the unit and previous units is compared and analyzed with the designed preset cooling capacity of these units. The determination formula is as follows:

[0080] ,

[0081] in, This represents the actual cooling input of the i-th unit. η represents the predetermined cooling input amount for the i-th unit, and η represents the cooling matching degree (dimensionless).

[0082] Specifically, the cooling capacity matching degree is used to indicate whether the actual input cooling capacity increases, decreases, or remains unchanged during the ventilation period of the next unit. After comparing the input cooling capacity with the predetermined amount, the total annual cooling capacity is precisely controlled through cross-unit cooling capacity surplus and deficit allocation. If the total cooling capacity input of a unit that has completed ventilation is insufficient, the deficit is allocated to the next unit to make up for it. Conversely, if the cooling capacity input of a unit that has completed ventilation is excessive, the excess is allocated to the next unit, thereby reducing the cooling capacity input of the next unit.

[0083] Further, as described in S4 above, the fan frequency control coefficient is determined based on the cooling capacity matching degree, using the following formula:

[0084] ,

[0085] in, η represents the fan frequency control coefficient, and η represents the cooling capacity matching degree.

[0086] The frequency of fan 14 is controlled according to the aforementioned fan frequency control coefficient, using the following formula:

[0087] ,

[0088] in, This indicates the fundamental frequency of fan 14. f fan This indicates the adjusted frequency of the wind turbine.

[0089] Based on the above-mentioned fan frequency control requirements, start the ventilation of the next unit, record the input cooling capacity of each unit, and repeat the above steps until the annual ventilation plan is completed, as described in S5 above.

[0090] In one possible implementation, please refer to Figure 6 The diagram illustrates a flowchart of an intelligent control method provided by another embodiment of the present invention. Specifically, the intelligent control method provided by this embodiment achieves dynamic thermal balance management through the coordinated operation of cooling capacity calculation and fan control. Cooling capacity calculation integrates temperature sensors to collect ambient temperature data in real time, and performs refined heat income and expenditure calculation based on a unit cooling capacity accounting algorithm, breaking down the total annual cooling capacity input into fixed baseline values ​​by unit. Fan control monitors airflow parameters through hot-wire anemometers, dynamically adjusting fan speed and ventilation valve opening to optimize cooling capacity delivery efficiency. This embodiment employs a feedforward-feedback composite control strategy. When the actual cooling capacity input of a unit is lower or higher than the baseline value, a cooling capacity compensation mechanism is automatically triggered—accumulating the difference to subsequent units, ensuring a constant annual cooling capacity input through iterative compensation across units. For example, when the input of the first unit is 50% of the baseline value, the second unit will simultaneously make up the difference of the first unit and add the current baseline value. If multiple units fail to reach the target, the difference will be rolled over and accumulated for compensation. This adaptive adjustment mechanism can not only ensure the stability of the total annual cooling supply, but also dynamically respond to fluctuations in environmental parameters, and realize high-precision closed-loop control of the thermodynamic system.

[0091] Furthermore, in conjunction with the intelligent control system provided in this embodiment of the invention, the invention forms a biomimetic lung-like branch structure through a ventilation network of transverse branch pipes and longitudinal main pipes pre-embedded between the roadbed fill layer and the active layer. This achieves triple heat exchange through cold, dry airflow driven by a variable frequency fan: first, forced convection removes the sensible heat accumulated in the fill layer; second, airflow accelerates moisture evaporation to consume latent heat; and third, it blocks the heat conduction path between the natural permafrost and the roadbed. The central control module of this system is equipped with a thermodynamic balance algorithm, which collects dual-modal data from temperature sensors and hot-wire anemometers in real time. Temperature field data is used to calculate the cold energy balance of the permafrost layer, triggering a compensation mechanism when a cold energy deficit is detected. Wind speed parameters are dynamically adjusted through a feedforward-feedback composite control strategy to adjust fan power and valve opening, forming a cyclical unit for rolling compensation of the cold energy input. This composite temperature control mode of "sensible heat and latent heat dissipation through dual paths + dynamic balance of cooling capacity budget" not only continues the passive heat dissipation advantage of the chimney effect of traditional ventilation ducts, but also controls the temperature fluctuation of frozen soil within a small range through active diffusion cooling technology. Compared with traditional methods, it significantly improves thermal stability, prevents heat accumulation, accelerates the thawing process of frozen soil, and maintains the internal temperature balance of frozen soil.

[0092] Further, please refer to Figure 6 The figure shows a comparison diagram of the control of ventilated roadbeds provided by the embodiments of the present invention. As shown in the figure, when the temperature rises during the warm season, if the basic wind speed is still used for ventilation, the cold energy introduced into the roadbed is insufficient to offset the increased heat intrusion. The upper limit of the human-made soil under the roadbed decreases rapidly, and the upper limit of the human-made soil under the roadbed will further deviate from the predetermined control target. The accounting-based wind speed control ventilation scheme can promptly increase the wind speed to supplement some of the cold energy reduced due to insufficient ventilation temperature difference and ventilation hours. Initially, due to the lag in the cold energy entering the frozen soil under the roadbed, the difference between the upper limit of the human-made soil under the roadbed under the accounting-based ventilation and the upper limit of the human-made soil under the roadbed under the basic wind speed ventilation is not significant. As the cold season arrives, the heat entering the frozen soil under the roadbed under the basic wind speed ventilation is significantly more than the heat entering the frozen soil under the roadbed under the accounting-based ventilation. Therefore, when the upper limit of the permafrost under the road surface is lowest in the second half of November, the difference between the two is significant. Under the basic wind speed ventilation method, the upper limit of the permafrost under the road surface is 0.41m lower than that under the accounting ventilation method.

[0093] Furthermore, it should be understood that the system disclosed in the embodiments of the present invention can be implemented in other ways. For example, the division of units is merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the communication connection between units may be through some interfaces, servers, or indirect coupling or communication connections, and may be electrical or other forms.

[0094] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each module can exist physically separately, or two or more modules can be integrated into one processing unit. The integrated unit described above can be implemented in hardware or as a software functional unit.

[0095] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for intelligent control of a ventilated roadbed with closed-loop regulation of annual cooling supply, wherein the ventilated roadbed is provided with an air inlet and an air outlet that allow airflow, and a fan (14) for air supply, characterized in that, The method includes: S1. Determine the annual cooling capacity based on the target roadbed, and decompose the annual cooling capacity into unit components and corresponding unit ventilation periods according to the historical temperature data of the target roadbed. S2. Obtain the temperature change, water vapor mass change, and air flow rate at the air inlet and outlet, and determine the actual input cooling capacity based on the temperature change, water vapor mass change, and air flow rate. S3. Based on the current unit ventilation period, obtain the cumulative actual input cooling capacity and cumulative unit cooling capacity of the unit ventilation periods that have been completed, and obtain the cooling capacity matching degree based on the cumulative actual input cooling capacity and cumulative unit cooling capacity; S4. Adjust the frequency of the fan (14) during the next unit ventilation period according to the cooling capacity matching degree; S5. Repeat S2 to S4 until the actual annual cooling input is equal to the annual cooling input. During the ventilation period of the first unit, the frequency of the fan (14) is set based on predetermined conditions.

2. The intelligent control method for ventilation roadbed with closed-loop annual cooling supply as described in claim 1, characterized in that, S1 specifically includes: The number of ventilation periods for each unit is preset, and the historical temperature data of each unit is divided according to the number of ventilation periods for each unit. The unit component is determined based on the proportion of the unit's historical temperature data corresponding to the ventilation period to the historical annual temperature data.

3. The intelligent control method for ventilation roadbed with closed-loop annual cooling supply as described in claim 1, characterized in that, The cooling capacity matching degree is used to indicate whether the actual input cooling capacity increases, decreases, or remains unchanged during the next unit ventilation period.

4. The intelligent control method for ventilation roadbed with closed-loop annual cooling supply as described in claim 1, characterized in that, S4 specifically includes: The fan frequency control coefficient is determined based on the cooling capacity matching degree, using the following formula: ， in, η represents the fan frequency control coefficient, and η represents the cooling capacity matching degree. The frequency of the fan (14) is controlled according to the aforementioned fan frequency control coefficient, and the formula is as follows: ， in, This indicates the fundamental frequency of the wind turbine. f fan This indicates the adjusted frequency of the wind turbine.

5. The intelligent control method for ventilation roadbed with closed-loop control of annual cooling supply according to claim 1, characterized in that, The unit component comprises 36 units, and the corresponding unit ventilation time period is 36 segments.

6. The intelligent control method for ventilation roadbed with closed-loop control of annual cooling supply according to claim 1, characterized in that, The method further includes: When the temperature difference between the air temperature and the ground temperature exceeds a predetermined threshold, the fan is controlled to start based on predetermined conditions.

7. A closed-loop intelligent control system for annual cooling supply of a ventilated roadbed, wherein the ventilated roadbed is provided with an air inlet and an air outlet that allow airflow, and a fan (14) for air supply, characterized in that, The system also includes a ventilation module (7), a wind speed monitoring module (11), a temperature monitoring module, and a central control module (15). The ventilation module (7) includes an air inlet pipe (71), an air outlet pipe (731), and a branch pipe (72). The branch pipe (72) is horizontally spaced between the air inlet pipe (71) and the air outlet pipe (731). The middle part of the air inlet pipe (71) is connected to the air inlet. The air outlet is symmetrically arranged at the edge of the ventilation roadbed, and the air outlet pipe (731) is correspondingly arranged, with one end connected to the air outlet and the other end connected to the air inlet pipe (71) through the branch pipe (72). The wind speed monitoring module (11) is used to monitor the water vapor mass change at the air inlet and air outlet; The temperature monitoring module is used to monitor the temperature changes at the air inlet and outlet, as well as the ground temperature. The central control module (15) is used to control the frequency of the fan (14) by adopting the intelligent control method for closed-loop regulation of annual cooling supply as described in any one of claims 1 to 5.

8. The intelligent control system for closed-loop regulation of annual cooling supply for ventilated roadbeds according to claim 7, characterized in that, The ventilated roadbed includes, from bottom to top, a gravelly clay layer (1), a silty clay layer (2), an active layer (3), a natural surface (13), a roadbed fill layer (4), a semi-rigid base layer (5), and an asphalt pavement layer (6). The ventilation module (7) is located above the natural surface (13) and below the roadbed fill layer (4).

9. The intelligent control system for closed-loop regulation of annual cooling supply for ventilated roadbeds according to claim 8, characterized in that, The temperature monitoring module is located below the natural surface (13). The temperature monitoring module includes a temperature sensor (10) located at the air inlet, a temperature sensor (10) located at the air outlet, and a temperature sensor (10) located in the middle of the ventilation module (7).

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