A subway tunnel temperature field perception-based air supply system

Abstract

The present application relates to a kind of based on subway tunnel temperature field perception air supply system, belong to subway ventilation and energy-saving control technical field.The system includes: temperature field perception unit, for real-time acquisition tunnel longitudinal temperature distribution data;Control unit, for identifying temperature abnormal area and spatial position, and obtain train real-time position to predict piston wind influence, air supply demand is compensated and corrected;Control unit is built-in start temperature threshold, enhancement temperature threshold and temperature rise rate threshold, according to the comparison result of air supply demand after compensation and correction and threshold, control the air supply device of corresponding section executes start, air volume regulation or stop action;Subarea air supply execution unit, including multiple independently controllable air supply device.By distributed temperature perception, piston wind compensation and multistage threshold control, realize subway tunnel on-demand accurate air supply, improve ventilation energy efficiency and temperature control response speed.

Description

Technical Field

[0001] This invention belongs to the field of subway ventilation and energy-saving control technology, specifically relating to an air supply system based on the temperature field sensing of subway tunnels. Background Technology

[0002] The ventilation system of subway tunnels is a crucial component in ensuring the comfort and safety of the subway operating environment. When subway trains run within tunnels, factors such as heat dissipation from the train's air conditioning condensers, heat generation from braking, and heat exchange between station public areas and the tunnel sections cause significant spatial non-uniformity and dynamic temporal variations in temperature distribution. Particularly in long tunnel sections, the piston-like airflow generated by frequent train starts and stops causes periodic changes in airflow direction, further exacerbating the complexity of the temperature field.

[0003] Currently, subway tunnel ventilation mainly employs two methods: one is natural ventilation using the piston wind generated by train operation; the other is mechanical ventilation using tunnel fans (TVF fans) or jet fans installed at both ends of the station or in the tunnel shafts. In actual operation, mechanical ventilation typically uses timed control or start-stop control based on a few discrete temperature sensors. For example, several point temperature sensors are installed at regular intervals inside the tunnel. When any sensor detects a temperature exceeding a preset threshold, the corresponding section's fan is activated; when the temperature drops below the threshold, the fan is shut down.

[0004] However, existing technologies have the following obvious shortcomings: First, the temperature sensing capability is limited. Point sensors can only reflect the local temperature at the installation point and cannot obtain the continuous temperature distribution along the entire tunnel. Due to the extremely uneven distribution of heat sources within the tunnel (such as sections where trains brake frequently or uphill sections), local hot spots are easily missed, leading to delayed or missing air supply response.

[0005] Second, the air supply control is crude. Existing systems typically use fixed air volume or simple on / off control, lacking the ability to precisely regulate airflow in zones based on the spatial distribution of the temperature field. When the temperature rises in a certain area, manual judgment or experience is often required to set the fan operating range, making it difficult to achieve on-demand air supply where it is hot, resulting in energy waste or poor temperature control.

[0006] Third, the dynamic interference of piston wind on the air supply effect is not considered. The direction of piston wind in subway tunnels changes in real time with the train's direction of travel. When the mechanical air supply direction is opposite to the piston wind direction, the air supply effect is weakened; when they are the same, it is enhanced. Existing control strategies cannot dynamically compensate for this effect based on the train's position, resulting in a mismatch between the air supply volume and actual demand—either insufficient or excessive air supply.

[0007] Fourth, there is a lack of multi-level early warning and intervention mechanisms. Existing systems typically only set a single temperature alarm threshold. When the temperature rises slowly but has not yet reached the threshold, the system does not respond; however, once the threshold is reached, the system is often already in a state of severe overheating. For operating conditions with abnormal temperature rise rates but low absolute values ​​(such as gradual temperature rise caused by train malfunctions), existing systems cannot identify them in time and provide early ventilation. Summary of the Invention

[0008] To address the aforementioned problems in the existing technology, this invention provides an air supply system based on temperature field sensing in subway tunnels. The objective of this invention can be achieved through the following technical solutions: An air supply system based on temperature field sensing in a subway tunnel includes: Temperature field sensing unit, used to collect and output longitudinal temperature distribution data of subway tunnel in real time; A control unit, connected to the temperature field sensing unit, is used to identify temperature anomaly areas and their corresponding spatial locations based on the temperature distribution data. The zoned air supply unit includes multiple independently adjustable air supply devices arranged longitudinally along the tunnel. The control unit is also configured to obtain the real-time running position of the subway train, predict the impact of piston wind on the temperature anomaly area based on the train position, and compensate and correct the air supply demand based on the piston wind prediction results. The control unit is preset with a start-up temperature threshold, an enhanced temperature threshold, and a temperature rise rate threshold, wherein the enhanced temperature threshold is higher than the start-up temperature threshold; the control unit is used to control the air supply device of the corresponding tunnel section to perform start-up, air volume adjustment, or stop actions based on the comparison result between the compensated and corrected air supply demand and the threshold.

[0009] As a preferred embodiment of the present invention, the temperature field sensing unit includes a temperature-sensing optical fiber continuously deployed along the longitudinal direction of the subway tunnel, and a demodulation host connected to the temperature-sensing optical fiber; the demodulation host emits laser pulses to the temperature-sensing optical fiber and receives backscattered light signals, and calculates continuous temperature distribution data along the longitudinal direction of the tunnel based on Raman scattering effect and optical time-domain reflectometry; the temperature-sensing optical fiber is continuously deployed along the entire tunnel, and the temperature distribution data corresponds to the temperature of the entire tunnel.

[0010] Specifically, when identifying the temperature anomaly area and its corresponding spatial location, a spatial positioning algorithm is used. The spatial positioning algorithm outputs a spatial location with a higher accuracy than the tunnel section interval corresponding to the adjacent air supply device. There is a one-to-one mapping relationship between the temperature anomaly area and the corresponding air supply device.

[0011] Specifically, obtaining the real-time running position of the subway train includes: connecting to the subway signaling system, the automatic train monitoring system, or the wireless positioning system, receiving real-time position, running direction, and speed information of the train from the system, and the control unit updating the train's movement trajectory in the tunnel based on the received information.

[0012] Specifically, the prediction of the impact of piston wind on the temperature anomaly area based on the train's position includes: calculating the time delay of piston wind propagation to the area, the expected wind direction and wind speed level, and determining the enhancement or weakening effect of piston wind on the expected air supply effect of the air supply device based on the relative distance between the train and the temperature anomaly area, the train's running direction and speed, combined with the tunnel cross-sectional dimensions and train shape parameters, and determining the result.

[0013] Specifically, the compensation and correction of air supply demand based on piston wind prediction results includes: reducing the output air volume demand of the air supply device when the predicted piston wind direction is consistent with the preset air supply direction of the air supply device; increasing the output air volume demand of the air supply device when the predicted piston wind direction is opposite to the preset air supply direction of the air supply device; and further increasing the compensation and correction magnitude when the predicted piston wind speed exceeds the set level.

[0014] Specifically, the preset start-up temperature threshold and enhanced temperature threshold in the control unit serve as the trigger conditions for starting the air supply device and increasing the air volume, respectively, and the enhanced temperature threshold is higher than the start-up temperature threshold; the temperature rise rate threshold serves as the upper limit for the rate of temperature rise per unit time in the temperature abnormal area, and the control unit outputs a control signal in advance when the absolute temperature value has not reached the start-up temperature threshold and the temperature rise rate exceeds the temperature rise rate threshold.

[0015] Specifically, the control of the ventilation device in the corresponding tunnel section to perform start-up, air volume adjustment, or stop actions includes: When the temperature value corresponding to the compensated and corrected air supply demand reaches the start-up temperature threshold but does not reach the enhanced temperature threshold, the corresponding air supply device is controlled to start air supply at the basic air volume. When the temperature value corresponding to the compensated and corrected air supply demand reaches the enhanced temperature threshold, the corresponding air supply device is controlled to enhance the air volume and continue to supply air. When the temperature value corresponding to the compensated and corrected air supply demand falls below the start-up temperature threshold and remains below the preset time, the corresponding air supply device is controlled to reduce the air volume or stop supplying air. When the temperature rise rate corresponding to the compensated and corrected air supply demand exceeds the temperature rise rate threshold, the corresponding air supply device will be controlled to start in advance or increase the air volume, regardless of whether the current temperature value has reached the start-up temperature threshold.

[0016] Specifically, the control unit is also configured to: construct a heat load change model for each section of the tunnel based on historical temperature distribution data and train operation diagrams; predict the temperature field change trend within a set time window in the future based on the heat load change model, and output a pre-start or pre-increase air volume signal to the air supply device of the corresponding section in advance before the predicted temperature anomaly occurs.

[0017] Specifically, each air supply device corresponds to an independent tunnel section, and the tunnel sections corresponding to adjacent air supply devices partially overlap or are seamlessly connected in space; the mapping relationship between each air supply device and its corresponding tunnel section is stored in the control unit, and the control unit matches the corresponding air supply device in the mapping relationship according to the spatial location of the temperature abnormal area.

[0018] Specifically, the control unit also determines whether the temperature abnormal area belongs to the station area or the tunnel area based on the spatial location of the area. If it belongs to the station area, the station air conditioning system or the station air supply device is called first to participate in temperature regulation, and the tunnel air supply device is coordinated to assist in air supply. If it belongs to the tunnel area, the air supply device of the corresponding section in the zone air supply execution unit is called for independent control.

[0019] Specifically, the control unit is further configured to: monitor the operating status of each air supply device and the temperature response time of the corresponding section, and dynamically correct the magnitude coefficient of the compensation correction based on the correspondence between the temperature response time and the air supply volume, so that the air supply response of different sections tends to be consistent.

[0020] The beneficial effects of this invention are as follows: Achieving blind-spot-free temperature sensing along the entire tunnel and eliminating monitoring blind spots: This invention employs temperature-sensing optical fibers continuously deployed along the tunnel's longitudinal direction, combined with Raman scattering and optical time-domain reflectometry (OTDR) technology, to acquire continuous temperature distribution data across the entire tunnel in real time, achieving spatial resolution down to the sub-segment level. Compared to traditional discrete-point sensors that only reflect local temperatures, this invention can accurately identify local hotspots at any location, avoiding delayed or missed air supply responses due to monitoring blind spots, and providing a reliable data foundation for precise zoned air supply.

[0021] Dynamic piston wind compensation based on train location improves ventilation efficiency: This invention obtains the real-time operating location of the subway train and, combined with the relative distance, direction, and speed of the train to the temperature anomaly area, predicts the time, direction, and speed of piston wind propagation to that area. When the predicted piston wind direction matches the preset direction of the ventilation device, the required ventilation volume is reduced, utilizing piston wind to assist ventilation and save energy; when the direction is opposite, the required ventilation volume is increased to overcome the offsetting effect of piston wind. This compensation mechanism dynamically matches the ventilation volume with actual demand, avoiding the problems of insufficient or excessive ventilation caused by neglecting piston wind in traditional control, and significantly improving ventilation efficiency.

[0022] Multi-level temperature threshold and temperature rise rate threshold coordinated control enables tiered early warning and intervention: This invention incorporates a start-up temperature threshold, an enhanced temperature threshold, and a temperature rise rate threshold, forming a multi-level control logic. When the temperature reaches the start-up threshold, the air supply device starts with a basic airflow; when the temperature continues to rise to the enhanced threshold, the airflow is automatically increased; when the temperature drops, the air supply is reduced or stopped, achieving tiered adjustment of air supply intensity and avoiding frequent start-stop cycles. Simultaneously, this invention introduces a temperature rise rate threshold: even if the current temperature has not yet reached the start-up threshold, if the temperature rise rate exceeds a set value (such as a gradual temperature rise caused by train malfunction or delay), the system can output a start-up or increased airflow signal in advance, achieving early warning and intervention, effectively preventing temperature runaway and improving operational safety.

[0023] Independent zone control and station / section differentiated control enable precise on-demand air supply: This invention arranges multiple independently controllable air supply devices along the longitudinal direction of the tunnel, each corresponding to an independent tunnel section. Adjacent sections partially overlap or seamlessly connect spatially, ensuring full air supply coverage. The control unit quickly matches the corresponding air supply device from a pre-stored mapping relationship based on the spatial location of temperature anomaly areas, activating air supply only in the anomaly sections while maintaining low-energy consumption in other sections, achieving on-demand air supply where it is hottest. Furthermore, this invention can distinguish between station areas and tunnel sections: the station area prioritizes the use of the air conditioning system to avoid interference with tunnel ventilation; the tunnel section independently utilizes jet fans or tunnel fans. This differentiated control strategy further reduces system energy consumption. Attached Figure Description

[0024] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0025] Figure 1 This is a block diagram of the overall system structure of the present invention; Figure 2 This is a system workflow diagram of the present invention; Figure 3 This is the timing diagram for the predictive control of the present invention; Figure 4 This is a schematic diagram of the closed-loop temperature feedback control of the present invention. Detailed Implementation

[0026] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0027] Please see Figures 1-4 An air supply system based on temperature field sensing in a subway tunnel includes: Temperature field sensing unit, used to collect and output longitudinal temperature distribution data of subway tunnel in real time; A control unit, connected to the temperature field sensing unit, is used to identify temperature anomaly areas and their corresponding spatial locations based on the temperature distribution data. The zoned air supply unit includes multiple independently adjustable air supply devices arranged longitudinally along the tunnel. The control unit is also configured to obtain the real-time running position of the subway train, predict the impact of piston wind on the temperature anomaly area based on the train position, and compensate and correct the air supply demand based on the piston wind prediction results. The control unit is preset with a start-up temperature threshold, an enhanced temperature threshold, and a temperature rise rate threshold, wherein the enhanced temperature threshold is higher than the start-up temperature threshold; the control unit is used to control the air supply device of the corresponding tunnel section to perform start-up, air volume adjustment, or stop actions based on the comparison result between the compensated and corrected air supply demand and the threshold.

[0028] Specifically, the temperature field sensing unit includes a temperature-sensing optical fiber continuously deployed along the longitudinal direction of the subway tunnel, and a demodulation host connected to the temperature-sensing optical fiber; the demodulation host emits laser pulses to the temperature-sensing optical fiber and receives backscattered light signals, and calculates continuous temperature distribution data along the longitudinal direction of the tunnel based on Raman scattering effect and optical time-domain reflectometry; the temperature-sensing optical fiber is continuously deployed along the entire tunnel, and the temperature distribution data corresponds to the temperature of the entire tunnel.

[0029] Specifically, when identifying the temperature anomaly area and its corresponding spatial location, a spatial positioning algorithm is used. The spatial positioning algorithm outputs a spatial location with a higher accuracy than the tunnel section interval corresponding to the adjacent air supply device. There is a one-to-one mapping relationship between the temperature anomaly area and the corresponding air supply device.

[0030] Specifically, obtaining the real-time running position of the subway train includes: connecting to the subway signaling system, the automatic train monitoring system, or the wireless positioning system, receiving real-time position, running direction, and speed information of the train from the system, and the control unit updating the train's movement trajectory in the tunnel based on the received information.

[0031] Specifically, the prediction of the impact of piston wind on the temperature anomaly area based on the train's position includes: calculating the time delay of piston wind propagation to the area, the expected wind direction and wind speed level, and determining the enhancement or weakening effect of piston wind on the expected air supply effect of the air supply device based on the relative distance between the train and the temperature anomaly area, the train's running direction and speed, combined with the tunnel cross-sectional dimensions and train shape parameters, and determining the result.

[0032] Specifically, the compensation and correction of air supply demand based on piston wind prediction results includes: reducing the output air volume demand of the air supply device when the predicted piston wind direction is consistent with the preset air supply direction of the air supply device; increasing the output air volume demand of the air supply device when the predicted piston wind direction is opposite to the preset air supply direction of the air supply device; and further increasing the compensation and correction magnitude when the predicted piston wind speed exceeds the set level.

[0033] Specifically, the preset start-up temperature threshold and enhanced temperature threshold in the control unit serve as the trigger conditions for starting the air supply device and increasing the air volume, respectively, and the enhanced temperature threshold is higher than the start-up temperature threshold; the temperature rise rate threshold serves as the upper limit for the rate of temperature rise per unit time in the temperature abnormal area, and the control unit outputs a control signal in advance when the absolute temperature value has not reached the start-up temperature threshold and the temperature rise rate exceeds the temperature rise rate threshold.

[0034] Specifically, the control of the ventilation device in the corresponding tunnel section to perform start-up, air volume adjustment, or stop actions includes: When the temperature value corresponding to the compensated and corrected air supply demand reaches the start-up temperature threshold but does not reach the enhanced temperature threshold, the corresponding air supply device is controlled to start air supply at the basic air volume. When the temperature value corresponding to the compensated and corrected air supply demand reaches the enhanced temperature threshold, the corresponding air supply device is controlled to enhance the air volume and continue to supply air. When the temperature value corresponding to the compensated and corrected air supply demand falls below the start-up temperature threshold and remains below the preset time, the corresponding air supply device is controlled to reduce the air volume or stop supplying air. When the temperature rise rate corresponding to the compensated and corrected air supply demand exceeds the temperature rise rate threshold, the corresponding air supply device will be controlled to start in advance or increase the air volume, regardless of whether the current temperature value has reached the start-up temperature threshold.

[0035] Specifically, the control unit is also configured to: construct a heat load change model for each section of the tunnel based on historical temperature distribution data and train operation diagrams; predict the temperature field change trend within a set time window in the future based on the heat load change model, and output a pre-start or pre-increase air volume signal to the air supply device of the corresponding section in advance before the predicted temperature anomaly occurs.

[0036] Specifically, each air supply device corresponds to an independent tunnel section, and the tunnel sections corresponding to adjacent air supply devices partially overlap or are seamlessly connected in space; the mapping relationship between each air supply device and its corresponding tunnel section is stored in the control unit, and the control unit matches the corresponding air supply device in the mapping relationship according to the spatial location of the temperature abnormal area.

[0037] Specifically, the control unit also determines whether the temperature abnormal area belongs to the station area or the tunnel area based on the spatial location of the area. If it belongs to the station area, the station air conditioning system or the station air supply device is called first to participate in temperature regulation, and the tunnel air supply device is coordinated to assist in air supply. If it belongs to the tunnel area, the air supply device of the corresponding section in the zone air supply execution unit is called for independent control.

[0038] Specifically, the control unit is further configured to: monitor the operating status of each air supply device and the temperature response time of the corresponding section, and dynamically correct the magnitude coefficient of the compensation correction based on the correspondence between the temperature response time and the air supply volume, so that the air supply response of different sections tends to be consistent.

[0039] Example I. Application Scenario Setting Taking the tunnel section between Jianguomen Station and Chaoyangmen Station on Metro Line 1 of a certain city as an example, this section is approximately 1.8 kilometers long and adopts a double-track tunnel design. The train interval is 2 minutes during peak hours and 5 minutes during off-peak hours. Two sets of jet fans are deployed in this section, located 500 meters and 1200 meters from Jianguomen Station respectively. Each set of jet fans can be independently controlled to rotate in both directions, achieving bidirectional air supply regulation. Temperature-sensing optical fibers are laid along the entire tunnel ceiling, with the ends of the fibers connected to a demodulation host located in the station control room, constructing a distributed temperature sensing network.

[0040] II. System Composition and Installation The air supply system in this embodiment specifically includes a temperature field sensing unit, a control unit, and a zoned air supply execution unit. The composition, installation method, and parameters of each unit are as follows: (a) Temperature field sensing unit A distributed fiber optic temperature sensing system (DTS) is employed as the core component for temperature field sensing. A single-mode temperature-sensing fiber, 1.8 kilometers long and consistent with the tunnel section, is laid along the tunnel arch. It is secured with clamps at a density of one hanging point every 1 meter to ensure full contact between the fiber and the tunnel environment, guaranteeing accurate temperature measurement. The fiber's tail end is connected to a demodulation unit (model: DTS-8000). This unit incorporates a laser source and signal processing module. Its operating mechanism involves emitting a laser pulse into the temperature-sensing fiber every 10 seconds and simultaneously receiving the backscattered Raman light signal returned by the fiber. Based on optical time-domain reflectometry, the spatial location of each temperature point is calculated, ultimately outputting continuous temperature distribution data along the tunnel's longitudinal direction. The spatial resolution is 1 meter, accurately capturing localized temperature anomalies within the tunnel. Simultaneously, the temperature field sensing unit collects real-time temperature data for the section after air supply and feeds it back to the control unit every 10 seconds, providing data support for the control unit to dynamically adjust control parameters, forming a closed-loop control system.

[0041] (ii) Control Unit An industrial-grade programmable logic controller (PLC) is installed in the station control room to achieve centralized control and coordinated scheduling of the system. The control unit establishes a signal connection with the demodulation host via Ethernet to receive temperature distribution data output by the temperature field sensing unit; it connects to the jet fan control cabinet via RS485 bus to output control commands to the zoned air supply execution unit; and it connects to the subway signaling system (ATS) via a dedicated signal interface to obtain real-time information on the train's location, direction of travel, and speed, providing a data foundation for piston wind prediction and air supply compensation correction.

[0042] (III) Zoned air supply execution unit Composed of two sets of jet fans, labeled F1 and F2, F1 corresponds to the tunnel section 500-1000 meters from Jianguomen Station, and F2 corresponds to the tunnel section 1000-1500 meters from Jianguomen Station. Adjacent sections are seamlessly connected to ensure complete air supply coverage throughout the tunnel. Each jet fan is equipped with a dedicated frequency converter, which can continuously adjust the air volume within the range of 0-100% and switch the air supply direction according to actual needs, meeting the air supply control requirements under different operating conditions.

[0043] III. Workflow Examples This embodiment describes the workflow of the air supply system in detail, taking into account different operating conditions of the subway, and comprehensively covers all control logics of the system to ensure the reproducibility and practicality of the technical solution.

[0044] (a) Normal cruise mode During normal train operation, the control unit continuously receives temperature distribution data transmitted by the temperature field sensing unit and real-time train operation information transmitted by the ATS system, maintaining a dynamic monitoring state. For example, at 10:00 AM, the temperature distribution curve output by the demodulator shows that the temperature 800 meters from Jianguomen Station (belonging to the F1 section) has risen to 28℃, while the temperature in adjacent sections remains at 26℃, forming a localized area of ​​higher temperatures. The control unit has a built-in start-up temperature threshold of 30℃, an enhanced temperature threshold of 35℃, and a temperature rise rate threshold of 2℃ / min. Since the current temperature of 28℃ does not reach the start-up temperature threshold, the system does not output ventilation control commands and remains in standby mode.

[0045] Meanwhile, the control unit, through the ATS system, learned that a train was departing from Jianguomen Station and heading towards Chaoyangmen Station. The current train position was 200 meters from Jianguomen Station, and its speed was 60 km / h. Based on this information, the control unit calculated that the relative distance between the train and the high-temperature area 800 meters away was 600 meters, and the train was expected to pass through this high-temperature area in 15 seconds. Combining the tunnel cross-sectional dimensions (5.2m wide × 4.8m high) and the train's external parameters, it further predicted that the piston wind direction was consistent with the train's direction of travel (i.e., from Jianguomen Station to Chaoyangmen Station), and the piston wind speed was approximately 4 m / s. Since the preset air delivery direction of the F1 fan was opposite to the train's direction of travel (i.e., from Chaoyangmen Station to Jianguomen Station), the piston wind would counteract the air delivery effect of the F1 fan. The control unit, considering the counteracting ratio of the piston wind speed to the air delivery effect, calculated an air delivery demand compensation coefficient of 1.3 times. At the same time, the control unit monitors the temperature rise rate of the area with high temperature in real time. In the past minute, the temperature in this area rose from 27.5℃ to 28℃, with a temperature rise rate of 0.5℃ / min, which did not exceed the preset threshold of 2℃ / min. Therefore, the control unit does not output the air supply control signal and continues to monitor.

[0046] (ii) Temperature reaches the start-up threshold and triggers air supply. At 10:05 AM, the temperature 800 meters from Jianguomen Station continued to rise to 30.2℃, reaching the preset start-up temperature threshold of the control unit. The control unit immediately invoked the compensation coefficient to compensate for the current air supply demand. The compensated air supply demand was equivalent to the air volume demand corresponding to 30.2℃ × 1.3 = 39.3℃. Based on this corrected air supply demand, the control unit issued a start command to the F1 fan, controlling the F1 fan to start supplying air at 60% of the base air volume, maintaining the preset air supply direction (i.e., from Chaoyangmen Station to Jianguomen Station). At this time, because the piston air direction is opposite to the air supply direction, it will cancel out part of the air supply effect. The actual effective air supply effect is equivalent to 40% of the base air volume. However, after compensation correction, the actual air supply effect is precisely matched with the target temperature control demand, ensuring that the abnormal temperature area is effectively controlled.

[0047] (iii) Early intervention when the rate of temperature rise exceeds the threshold In another implementation scenario, a train stopped 1100 meters from Jianguomen Station (within the F2 section) due to a malfunction. The train's air conditioning condenser continuously dissipated heat, causing the temperature in the area to rise rapidly. Initially, the temperature in this area was 28℃, but monitoring data showed that the temperature rose by 2.5℃ per minute, exceeding the control unit's preset temperature rise rate threshold of 2℃ / min. Although the current temperature had not reached the 30℃ activation temperature threshold, the control unit, upon detecting the excessive temperature rise rate, immediately activated the early intervention mechanism, issuing a pre-start command to the F2 fan, controlling it to start airflow at 30% capacity to continuously cool the area. Two minutes later, the temperature in the area rose to 31℃. Due to the early intervention, the temperature rise rate decreased to 0.8℃ / min, effectively preventing high-temperature accumulation in the tunnel section and ensuring tunnel operational safety.

[0048] (iv) Increase airflow when the temperature reaches the enhancement threshold. If the temperature in the abnormal temperature area continues to rise and reaches the 35°C enhanced temperature threshold preset by the control unit, the control unit will immediately issue an airflow enhancement command to the fan in the corresponding section. For example, when the temperature at 800 meters rises to 35°C, the control unit will issue a command to the F1 fan to increase the airflow of the F1 fan from 60% to 100% (i.e., enhance the airflow) and continue to supply air until the temperature in that area drops back to a safe range.

[0049] (v) Stop air supply when temperature drops When the temperature in the abnormal temperature area drops to 29℃ (below the start-up temperature threshold of 30℃) and remains stable for 30 seconds, the control unit initiates the air supply stop procedure. First, the air supply volume of the corresponding fan is reduced to 30%, and then the air supply is maintained for 1 minute. After confirming that the temperature does not rebound, the control unit finally issues a stop air supply command to the fan, and the system returns to normal cruise monitoring status.

[0050] (vi) Differentiated control of stations and sections When the temperature anomaly area is located at the connection between the platform and the tunnel at Jianguomen Station, the control unit determines that the area is the connection zone between the station and the tunnel based on the spatial location information of the temperature anomaly area. In this case, the control unit prioritizes coordinating with the ventilation equipment in the adjacent tunnel to provide auxiliary ventilation, while simultaneously controlling the F1 fan in the tunnel section to provide auxiliary ventilation at 20% of its capacity. This ensures reasonable allocation of airflow, avoids airflow short-circuiting, and guarantees effective temperature control. If the temperature anomaly area is located inside the tunnel section (not the connection zone), the control unit only independently controls the jet fan in the corresponding section, without activating the station's ventilation equipment, thus reducing energy consumption.

[0051] (vii) Predictive control The control unit has a built-in data storage module that stores tunnel temperature distribution data and train operation schedules from the past week, and constructs a heat load variation model for each section of the tunnel based on this data. During the morning rush hour (e.g., 8:30 AM), the heat load variation model predicts that between 8:35 and 8:45 AM, the section 700-900 meters from Jianguomen Station (corresponding to F1) will generate a large amount of heat due to continuous braking by multiple trains, and the temperature will rise to 32°C. To avoid high-temperature shocks, the control unit sends a pre-start signal to the F1 fan 2 minutes in advance (i.e., 8:33 AM), controlling the F1 fan to supply air at 20% capacity in advance, forming a stable airflow barrier before the temperature rises. Actual operation data shows that the peak temperature in this area during this period is controlled below 33°C, effectively avoiding the risk of high temperatures and improving the timeliness and stability of temperature control.

[0052] (viii) Adaptive correction The control unit records the temperature response time (i.e., the time required for the temperature to drop by 1°C) of each jet fan under different air volumes in real time, and dynamically optimizes the compensation and correction strategy based on this data. For example, monitoring data shows that the temperature response time of fan F1 at 60% air volume is 45 seconds, while that of fan F2 at the same air volume is 60 seconds, indicating a difference in temperature control response between the two sections. The control unit automatically adjusts the compensation coefficient of fan F2, gradually shortening its temperature response time to approach the 45-second response time of fan F1, ensuring consistent temperature control response across all sections of the tunnel and improving the overall temperature control effect.

[0053] (ix) Fault redundancy control To ensure system reliability and prevent temperature control interruptions due to single fan failure, the system is equipped with fault redundancy control logic. When the control unit detects a fault in a fan (such as fan F1) and its inability to operate normally, it immediately activates the redundancy compensation mechanism, controlling the adjacent fan (such as fan F2) to increase the air volume to 80%, expanding the air supply coverage to cover the 500-1000 meter section corresponding to fan F1, until fan F1 is repaired and resumes normal operation, ensuring uninterrupted tunnel temperature control and guaranteeing subway operation safety.

[0054] IV. Verification of Beneficial Effects The ventilation system in this embodiment has completed real-world scenario testing. The testing conditions were: 7 consecutive days (including 3 weekday peak hours, 2 off-peak hours, and 2 nighttime hours). During the test, the train operation intensity was consistent with the actual operation of Metro Line 1, and the outdoor ambient temperature was 28-32℃. The test data is the 7-day average. Test results show that compared with traditional timed ventilation methods, the ventilation system in this embodiment has significant technical advantages: ventilation energy consumption is significantly reduced, the highest temperature of local hot spots in the tunnel decreased by 4℃, effectively improving the temperature environment inside the tunnel and enhancing passenger comfort. Simultaneously, through an early intervention mechanism, three high-temperature alarms caused by train malfunctions were successfully avoided during the 7-day test, effectively ensuring the operational safety of the metro tunnel and possessing extremely high engineering practical value and promotional significance.

[0055] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A ventilation system based on temperature field sensing in a subway tunnel, characterized in that, include: Temperature field sensing unit, used to collect and output longitudinal temperature distribution data of subway tunnel in real time; A control unit, connected to the temperature field sensing unit, is used to identify temperature anomaly areas and their corresponding spatial locations based on the temperature distribution data. The zoned air supply unit includes multiple independently adjustable air supply devices arranged longitudinally along the tunnel. The control unit is also configured to obtain the real-time running position of the subway train, predict the impact of piston wind on the temperature anomaly area based on the train position, and compensate and correct the air supply demand based on the piston wind prediction results. The control unit is preset with a start-up temperature threshold, an enhanced temperature threshold, and a temperature rise rate threshold, wherein the enhanced temperature threshold is higher than the start-up temperature threshold; the control unit is used to control the air supply device of the corresponding tunnel section to perform start-up, air volume adjustment, or stop actions based on the comparison result between the compensated and corrected air supply demand and the threshold.

2. The system according to claim 1, characterized in that, The temperature field sensing unit includes a temperature-sensing optical fiber continuously deployed along the longitudinal direction of the subway tunnel, and a demodulation host connected to the temperature-sensing optical fiber; the demodulation host emits laser pulses into the temperature-sensing optical fiber and receives backscattered light signals, and calculates continuous temperature distribution data along the longitudinal direction of the tunnel based on Raman scattering effect and optical time-domain reflectometry; the temperature-sensing optical fiber is continuously deployed along the entire tunnel, and the temperature distribution data corresponds to the temperature of the entire tunnel.

3. The system according to claim 1, characterized in that, When identifying temperature anomaly areas and their corresponding spatial locations, a spatial positioning algorithm is used. The spatial positioning accuracy output by the algorithm is higher than the tunnel section interval corresponding to adjacent air supply devices, and there is a one-to-one mapping relationship between temperature anomaly areas and their corresponding air supply devices.

4. The system according to claim 1, characterized in that, The process of obtaining the real-time running position of the subway train includes: connecting to the subway signaling system, the automatic train monitoring system, or the wireless positioning system, receiving real-time position, running direction, and speed information of the train from the system, and the control unit updating the train's movement trajectory in the tunnel based on the received information.

5. The system according to claim 1, characterized in that, The method of predicting the impact of piston wind on the temperature anomaly area based on the train's position specifically includes: calculating the time delay of piston wind propagation to the area, the expected wind direction and wind speed level, and determining the enhancement or weakening effect of piston wind on the expected air supply effect of the air supply device based on the relative distance between the train and the temperature anomaly area, the train's running direction and speed, combined with the tunnel cross-sectional dimensions and train shape parameters, and determining the result.

6. The system according to claim 1, characterized in that, The compensation and correction of air supply demand based on piston wind prediction results specifically includes: reducing the output air volume requirement of the air supply device when the predicted piston wind direction is consistent with the preset air supply direction of the air supply device; increasing the output air volume requirement of the air supply device when the predicted piston wind direction is opposite to the preset air supply direction of the air supply device; and further increasing the compensation and correction magnitude when the predicted piston wind speed exceeds the set level.

7. The system according to claim 1, characterized in that, The preset start-up temperature threshold and enhanced temperature threshold in the control unit serve as the trigger conditions for starting the air supply device and increasing the air volume, respectively, and the enhanced temperature threshold is higher than the start-up temperature threshold; the temperature rise rate threshold serves as the trigger upper limit for the rate of temperature rise per unit time in the temperature abnormal area, and the control unit outputs a control signal in advance when the absolute temperature value has not reached the start-up temperature threshold and the temperature rise rate exceeds the temperature rise rate threshold.

8. The system according to claim 1, characterized in that, The control of the ventilation device in the corresponding tunnel section to perform start-up, air volume adjustment, or stop actions specifically includes: When the temperature value corresponding to the compensated and corrected air supply demand reaches the start-up temperature threshold but does not reach the enhanced temperature threshold, the corresponding air supply device is controlled to start air supply at the basic air volume. When the temperature value corresponding to the compensated and corrected air supply demand reaches the enhanced temperature threshold, the corresponding air supply device is controlled to enhance the air volume and continue to supply air. When the temperature value corresponding to the compensated and corrected air supply demand falls below the start-up temperature threshold and remains below the preset time, the corresponding air supply device is controlled to reduce the air volume or stop supplying air. When the temperature rise rate corresponding to the compensated and corrected air supply demand exceeds the temperature rise rate threshold, the corresponding air supply device will be controlled to start in advance or increase the air volume, regardless of whether the current temperature value has reached the start-up temperature threshold.

9. The system according to claim 1, characterized in that, The control unit is also configured to: construct a heat load change model for each section of the tunnel based on historical temperature distribution data and train operation diagrams; predict the temperature field change trend within a set time window in the future based on the heat load change model, and output a pre-start or pre-increase air volume signal to the air supply device of the corresponding section in advance before the predicted temperature anomaly occurs.

10. The system according to claim 1, characterized in that, The air supply device corresponds to an independent tunnel section, and the tunnel sections corresponding to adjacent air supply devices partially overlap or are seamlessly connected in space; the mapping relationship between each air supply device and its corresponding tunnel section is stored in the control unit, and the control unit matches the corresponding air supply device in the mapping relationship according to the spatial location of the temperature abnormal area.

11. The system according to claim 1, characterized in that, The control unit also determines whether the area with abnormal temperature belongs to the station area or the tunnel area based on the spatial location of the area; if it belongs to the station area, it prioritizes calling the station air conditioning system or the station air supply device to participate in temperature regulation, and coordinates the tunnel air supply device to assist in air supply. If it belongs to the tunnel area, only the air supply device of the corresponding section in the zone air supply execution unit will be called for independent control.

12. The system according to claim 1, characterized in that, The control unit is also configured to: monitor the operating status of each air supply device and the temperature response time of the corresponding section, and dynamically correct the magnitude coefficient of the compensation correction based on the correspondence between the temperature response time and the air supply volume, so that the air supply response of different sections tends to be consistent.

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