Cable tunnel intelligent cooling system based on cold water pipe longitudinal partition and working method

Abstract

The invention discloses a cable tunnel intelligent cooling system based on cold water pipe longitudinal partition and a working method. The cooling system comprises a cold water pipe network system, and the cold water pipe network system is composed of a first-stage water circulation system, a second-stage water circulation system and a plate heat exchanger; the first-stage water circulation systems are arranged on the two sides of the cable tunnel respectively, and each first-stage water circulation system comprises a cooler, a first-stage circulating water pump, a cold water supply main pipe and a cold water return main pipe; the cable tunnel is divided into a plurality of areas in the longitudinal direction of the cable tunnel, the two sides of each area are each provided with a second-stage water circulation system and a plate heat exchanger, and each second-stage water circulation system comprises a first longitudinal pipe, a second longitudinal pipe, a first vertical pipe, a second vertical pipe, a first fin type cooling coil pipe, a second fin type cooling coil pipe and a second-stage circulation water pump. The system has the advantages that the pipe network layout of the longitudinal cold curtain and the partition circulation breaks through the limitation of traditional point type cooling;

Description

Technical Field

[0001] This invention relates to the technical field of cable tunnel cooling, and in particular to an intelligent cooling system and working method for cable tunnels based on longitudinal partitioning of cold water pipes. Background Technology

[0002] With the acceleration of urbanization and the growth of electricity demand, cable tunnels, as the core channels for power transmission, are directly related to the stability of the power grid and urban functions. However, the complex operating conditions within cable tunnels lead to frequent temperature anomalies, which may trigger a chain of failures such as accelerated insulation aging, arcing, and even fires. Studies have shown that when the ambient temperature is only 20℃ and the current is 110A, the highest internal temperature of the cable conductors in a triangular-layout configuration can reach 42.2℃, and the thermal radiation range expands with increasing voltage levels. This temperature runaway not only shortens the cable's lifespan (e.g., long-term high-temperature operation can increase the aging rate of insulation materials by more than 30%), but may also cause tunnel ambient temperatures as high as 60℃, forcing the power system to take emergency load control measures.

[0003] The two main cooling methods for cable tunnels both domestically and internationally are air cooling and water cooling. Air cooling utilizes the tunnel's ventilation system to remove heat generated by the cables. Depending on the tunnel's structure, length, construction process, cable laying conditions, and outdoor meteorological parameters, ventilation methods are mainly divided into natural ventilation and mechanical ventilation. Natural ventilation is powered by wind pressure and thermal pressure, and is primarily suitable for small cable tunnels with limited cable capacity and short ventilation sections. Mechanical ventilation systems consist of supply and exhaust fans, dampers, and ductwork, employing a longitudinal ventilation method. Air shafts and fan rooms are located at both ends of the tunnel, with supply and exhaust fans installed in each room to overcome the ventilation resistance along the tunnel length. For long-distance cable tunnel cooling, existing large-scale cross-river (sea) cable tunnels all utilize ventilation systems to remove excess heat. For example, the Sutong GIL integrated utility tunnel project uses large axial flow fans for supply and exhaust ventilation to remove excess heat from the tunnel. However, simulation data shows that increasing the cross-sectional wind speed from 0.5 m / s to 1.0 m / s can reduce the temperature in the high-temperature area by 6.81°C, but the marginal cooling effect decreases significantly when the speed is further increased to 2.0 m / s. Therefore, traditional ventilation and cooling strategies are difficult to apply to ultra-long cable tunnels.

[0004] Water cooling can be divided into direct water cooling and indirect water cooling. The heat dissipated by the cable is first transferred to the air inside the tunnel, and then transferred to the cooling water pipes through the air medium. The cooling water pipes are laid along the cable route, responding to the linear characteristics of the cable's heat source, to absorb the heat generated by the cable in a timely manner. At the same time, water's cooling capacity is much greater than that of air, so this scheme has high cooling efficiency. However, due to the large amount of heat generated by the cable, the required length of the cooling water pipes is relatively long. Furthermore, the direct entry of high-humidity outdoor air into the tunnel and its convection heat exchange with the cooling water pipes will result in a large amount of condensate, leading to excessive humidity inside the cable tunnel, making traditional cooling water pipe layouts unsuitable.

[0005] Traditional cable tunnel cooling technologies suffer from the following technical challenges: (1) Due to the excessively long air heat exchange path, the temperature rise at the end of the ultra-long tunnel (>500m) is significant (e.g., the temperature at the tunnel exit may reach above 60℃ in summer), and the cooling demand cannot be met by relying solely on the air supply of fans.

[0006] (2) The cable generates a lot of heat, and the single cooling water solution requires a long layout length. In addition, the outdoor high humidity air directly enters the tunnel and convects with the cooling water pipe, which will cause a large amount of condensate and result in excessive humidity inside the cable tunnel.

[0007] (3) Conventional ventilation or cold water cooling schemes only start and stop based on a fixed temperature difference threshold, without considering the dynamic changes of cable load and uneven heat field distribution. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of the prior art by providing an intelligent cooling system and operating method for cable tunnels based on longitudinal partitioning of cold water pipes. This cooling system includes a cold water pipe network system and a linked ventilation device. By integrating longitudinal partitioning of cold water circulation, fiber optic temperature measurement, and dynamic algorithms, it effectively solves the problem of heat accumulation in ultra-long cable tunnels, combining the advantages of high-efficiency cooling and energy saving. It is suitable for high-load tunnel scenarios in fields such as power and transportation.

[0009] The objective of this invention is achieved through the following technical solutions: A smart cooling system for cable tunnels based on longitudinal partitioning of cold water pipes. The cooling system includes a cold water pipe network system, which consists of a primary water circulation system, a secondary water circulation system, and a plate heat exchanger. The primary water circulation system is located on both sides of the cable tunnel and includes a chiller, a primary circulating water pump, a cold water supply main, and a cold water return main. The inlet and outlet of the cold water supply main are connected to the outlet of the primary circulating water pump and the inlet of the cold water return main, respectively. The inlet and outlet of the chiller are connected to the outlet of the cold water return main and the inlet of the primary circulating water pump, respectively. Both the cold water supply and return mains are arranged longitudinally along the cable tunnel. The cold water supply main and the cold water return main are arranged vertically relative to each other; the cable tunnel is divided into multiple areas along its longitudinal direction, and each area is provided with a secondary water circulation system and a plate heat exchanger on both sides. The secondary water circulation system includes a first longitudinal pipe, a second longitudinal pipe, a first vertical pipe, a second vertical pipe, a first finned cooling coil, a second finned cooling coil, and a secondary circulating water pump. The secondary circulating water pump and the first finned cooling coil are both arranged on the first vertical pipe, and the second finned cooling coil is arranged on the second vertical pipe. The primary side of the plate heat exchanger is installed on the cold water supply main of the primary water circulation system, and the secondary side of the plate heat exchanger is installed on the second longitudinal pipe of the secondary water circulation system.

[0010] The cable tunnel is equipped with a distributed optical fiber temperature measurement device along its longitudinal direction.

[0011] The secondary circulating water pump is controlled by an intelligent temperature control device, and the distributed fiber optic temperature measurement device is communicatively connected to the intelligent temperature control device.

[0012] The cooling system also includes a linkage ventilation device, which consists of a jet fan and an intelligent airflow adjustment system. The jet fan is controlled by the intelligent airflow adjustment system, which is communicatively connected to the intelligent temperature control device.

[0013] The direction of the airflow from the jet fan is opposite to the direction of the water flow from the cold water supply main.

[0014] The cold water supply main pipe is located at a certain distance below the cable support, and the cold water return main pipe is located at the top of the side wall of the cable trench.

[0015] The water flow direction on the primary side of the plate heat exchanger is opposite to the water flow direction on the secondary side of the plate heat exchanger.

[0016] A method for operating a cable tunnel intelligent cooling system based on longitudinal partitioning of cold water pipes, the method comprising the following steps: S1: Real-time acquisition of cable surface temperature T cable (t), tunnel internal temperature T room (t), cable load P load (t); S2: Calculate cable surface temperature T cable (t) and the set target temperature T set The deviation Δ between T cable (t) and the temperature inside the tunnel T room (t) and the set target temperature T set The deviation Δ between T room (t): Δ T cable (t) = T cable (t)− T set ; Δ T room (t) = T room (t)− T set ; S3: Dynamically adjust the cold water flow rate of the secondary circulating water pump. Q water (t): Q water (t)= K p (Δ T cable (t)+Δ T room (t))+ K i ∫(Δ T cable (t)+Δ T room (t)) d t+ K d ( d (Δ T cable (t)+Δ T room (t)) / d t); In the formula, Kp , K i , K d These are proportional, integral, and differential constants, which control the sensitivity, long-term deviation, and instantaneous change of the response, respectively. S4: When Δ T cable (t)>threshold Δ T critical At that time, activate the linkage ventilation device and adjust the speed of the jet fan. Q fan (t) = K f Δ T room (t), K f This is the control constant for the speed of the jet fan; S5: Real-time solution of the objective function based on optimization algorithms: Min (∑ t ( α ⋅Δ T cable (t) + β ⋅Δ T room (t) + gamma ⋅ Q water (t) + delta ⋅ Q fan (t))); In the formula, α , β , gamma , delta These are the weighting coefficients.

[0017] The advantages of this invention are: 1. The vertical cooling curtain combined with the zoned circulation pipe network layout breaks through the limitations of traditional point cooling; 2. By integrating fiber optic temperature measurement and dynamic cooling distribution algorithms, meter-level temperature field control can be achieved; 3. Energy consumption is saved through the collaboration between the intelligent temperature control module and the cold water pipe network. Attached Figure Description

[0018] Figure 1 This is an overall layout diagram of the intelligent cooling system for cable tunnels based on longitudinal partitioning of cold water pipes according to the present invention. Figure 2 This is a layout diagram of the primary water circulation system of the present invention; Figure 3 This is a layout diagram of the two-stage water circulation system of the present invention; Figure 4This is a layout diagram of the linkage ventilation device of the present invention; like Figures 1-4 As shown in the figure, the markings represent: 1. Chiller; 2. Primary circulating water pump; 3. Chiller water supply main; 4. Chiller water return main; 5. Plate heat exchanger; 6. First longitudinal pipe; 7. Second longitudinal pipe; 8. First vertical pipe; 9. Second vertical pipe; 10. First finned cooling coil; 11. Second finned cooling coil; 12. Secondary circulating water pump; 13. Distributed fiber optic temperature measurement device; 14. Linked ventilation device; 15. Intelligent temperature control device. Cable tunnel A, cable B. Detailed Implementation

[0019] The features and other related features of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments, so as to facilitate understanding by those skilled in the art: Example: Figures 1-4As shown, this embodiment relates to an intelligent cooling system for cable tunnels based on longitudinal partitioning of cold water pipes. The cooling system mainly includes a cold water pipe network system and a linkage ventilation device. Both the cold water pipe network system and the linkage ventilation device are installed in cable tunnel A. Cable B is installed along the longitudinal direction of cable tunnel A. Cable B is installed in both the vertical and horizontal directions. The upper cable B is installed on the cable support, and the lower cable B is installed in the cable trench. Distributed optical fiber temperature measuring devices 13 are installed along the longitudinal direction of cable tunnel A, with temperature measuring points set every 5m to monitor the surface temperature of cable B and the ambient temperature gradient of cable tunnel A in real time. The cold water pipe network system consists of a primary water circulation system, a secondary water circulation system, and a plate heat exchanger 5. The primary water circulation system and the secondary water circulation system exchange heat through the plate heat exchanger 5. The primary water circulation system is installed on both sides of the transverse direction of cable tunnel A. The primary water circulation system includes a chiller 1, a primary circulating water pump 2, a chilled water supply main 3, and a chilled water return main 4. The inlet and outlet of the chilled water supply main 3 are connected to the outlet of the primary circulating water pump 2 and the inlet of the chilled water return main 4, respectively. The inlet and outlet of the chiller 1 are connected to the outlet of the chilled water return main 4 and the inlet of the primary circulating water pump 2, respectively. The cold water supply main pipe 3 and the cold water return main pipe 4 are both arranged longitudinally along the cable tunnel A and are arranged vertically relative to each other. The cold water supply main pipe 3 is located at a certain distance below the cable support (0.5m in this embodiment), and the cold water return main pipe 4 is located at the top of the side wall of the cable trench. The primary circulating water pump 2 pumps the cold water in the chiller 1 into the cold water supply main pipe 3, and the cold water flows back to the chiller 1 through the cold water return main pipe 4, forming a water circulation. Cable tunnel A is divided into multiple zones along its longitudinal direction (each zone is 200m long). Each zone has a secondary water circulation system and a plate heat exchanger 5 on both sides of its transverse direction. The secondary water circulation system includes a first longitudinal pipe 6, a second longitudinal pipe 7, a first vertical pipe 8, a second vertical pipe 9, a first finned cooling coil 10, a second finned cooling coil 11, and a secondary circulating water pump 12. The first longitudinal pipe 6 and the second longitudinal pipe 7 are arranged vertically opposite each other. The secondary circulating water pump 12 and the first finned cooling coil... All coils 10 are arranged on the first vertical pipe 8, and the second finned cooling coil 11 is arranged on the second vertical pipe 9. The inlet and outlet of the secondary circulating water pump 12 are respectively connected to the outlet of the second finned cooling coil 11 and the inlet of the first finned cooling coil 10. The outlet of the first finned cooling coil 10 is connected to the inlet of the second finned cooling coil 11. Both the first finned cooling coil 10 and the second finned cooling coil 11 are spiral-shaped and directly in contact with the air for heat absorption.The primary side of the plate heat exchanger 5 is installed on the cold water supply main 3 of the primary water circulation system, meaning that both the inlet and outlet of the primary side of the plate heat exchanger 5 are connected to the cold water supply main 3. The secondary side of the plate heat exchanger 5 is installed on the second longitudinal pipe 7 of the secondary water circulation system, meaning that both the inlet and outlet of the secondary side of the plate heat exchanger 5 are connected to the second longitudinal pipe 7. In this embodiment, the water flow direction on the primary side of the plate heat exchanger 5 is opposite to the water flow direction on the secondary side, which can improve the heat exchange efficiency between the primary and secondary water circulation systems. The secondary circulating water pump 12 is controlled by an intelligent temperature control device 15, and a distributed fiber optic temperature measuring device 13 is communicatively connected to the intelligent temperature control device 15. The intelligent temperature control device 15 controls a PID controller based on the measurement data from the distributed fiber optic temperature measuring device 13 to adjust the flow rate at the output of the secondary circulating water pump 12, thereby adjusting the flow rate of the finned cooling coil.

[0020] like Figures 1-4 As shown, the linkage ventilation device 14 consists of a jet fan and an intelligent airflow adjustment system. The intelligent airflow adjustment system controls the direction and speed of the jet fan. The intelligent airflow adjustment system is communicatively connected to the intelligent temperature control device 15. The intelligent temperature control device 15 controls the intelligent airflow adjustment system based on the measurement data from the distributed fiber optic temperature measuring device 13 to adjust the direction and speed of the jet fan. The airflow direction of the jet fan is opposite to the water flow direction of the cold water supply main pipe 3, which improves the heat dissipation effect.

[0021] Specifically, the design of the finned cooling coil increases the heat exchange area and improves heat exchange efficiency: By increasing the surface area of ​​the fins, the finned cooling coil enhances the cooling effect. The cold water flowing inside the finned cooling coil accelerates heat exchange through the fins, increasing the contact area between the cold water and the surrounding air, thereby improving the heat transfer rate. When airflow passes through, the finned cooling coil can effectively transfer cold energy to the air in cable tunnel A, thereby reducing the temperature of cable tunnel A. Compared with traditional simple pipe cooling, the finned cooling coil can reduce the temperature more efficiently. The design of the linkage ventilation device 14 can enhance airflow and optimize airflow distribution: the jet fan further enhances the heat exchange effect between the finned cooling coil and the surrounding air by forcing airflow. The jet fan can effectively improve the convective heat exchange capacity of the air around the finned cooling coil, making the cooling effect more uniform. The jet fan can help improve the airflow distribution in the cable tunnel A and avoid the situation of excessively high or low temperature in some areas. Through reasonable jet fan arrangement and wind speed control, the cooling can be more uniform and efficient. The intelligent temperature control device 15 is designed to achieve intelligent control and energy-saving management. It dynamically adjusts the cooling output of the finned cooling coil and the speed of the jet fan based on real-time temperature data. The device optimizes the temperature distribution within cable tunnel A in real time, ensuring ideal cooling for each area. Through the coordinated adjustment of the jet fan and chilled water network system, the jet fan can reduce its speed or temporarily shut down when the load is low, reducing energy consumption. Conversely, when the load is high, the jet fan and chilled water network system can fully utilize their efficiency for rapid cooling. In summary, the combination of the finned cooling coil and jet fan purging is an effective solution for improving the cooling efficiency of cable tunnel A. The coil provides efficient heat exchange, while the jet fan further enhances the cooling effect by increasing airflow rate and uniformity. Combined with intelligent control and temperature control technology, the entire system ensures high efficiency, energy saving, and precise cooling requirements for different areas, avoiding the uneven temperature and low efficiency problems of traditional cooling methods.

[0022] like Figures 1-4 As shown, this embodiment also includes a working method for an intelligent cooling system for cable tunnels based on longitudinal partitioning of cold water pipes. This working method mainly includes the following steps: S1: Real-time acquisition of cable surface temperature T cable (t), tunnel internal temperature T room (t), cable load P load (t).

[0023] S2: Calculate cable surface temperature T cable(t) and the set target temperature T set The deviation Δ between T cable (t) and the temperature inside the tunnel T room (t) and the set target temperature T set The deviation Δ between T room (t): Δ T cable (t) = T cable (t)− T set ; Δ T room (t) = T room (t)− T set .

[0024] S3: The cold water flow rate of the secondary circulating water pump 12 (output end) is dynamically adjusted by the PID controller of the intelligent temperature control device 15. Q water (t): Q water (t)= f ( T cable (t), T room (t), P load (t))= K p (Δ T cable (t)+Δ T room (t))+ K i ∫(Δ T cable (t)+Δ T room (t)) d t+ K d ( d (Δ T cable (t)+Δ T room (t)) / d t); In the formula, K p , Ki , K d These are proportional, integral, and differential constants, which respectively control the sensitivity, long-term deviation, and instantaneous change of the response.

[0025] In this embodiment, K p The proportional controller determines the ratio between the controller output and the current error. If the error is large, the proportional controller will make significant adjustments. K p A larger setting results in a faster system response, but may also lead to overreaction (i.e., overshoot). Conversely, a smaller setting results in a slower system response, potentially preventing the system from quickly reaching the target value. K p Typical values ​​can range from 0.1 to 10, depending on the system's stability requirements and feedback characteristics. K i Adjusting the value based on the cumulative error (i.e., the accumulation of error over time) helps eliminate long-term deviations, especially when proportional control cannot completely eliminate the error. Setting it too high may cause system oscillations or overcorrection because the integral term will continuously accumulate, leading to a continuous increase in the controller output. Conversely, setting it too low will make it difficult to eliminate long-term deviations; it is typically less than the proportional constant. K p The typical value ranges from 0.01 to 1.0. K d Adjusting the controller output by estimating the instantaneous trend of error change helps reduce system overshoot, especially when the error changes rapidly. If the value is set too high, the system may become too sensitive and overreact. If the value is set too low, it will not be able to effectively suppress the rapid change of error, which may lead to slow system response or oscillation. The value is usually small, with a typical range of 0.01 to 1.0.

[0026] By adjusting the cold water flow rate of the secondary circulating water pump 12 Q water (t) to achieve the chilled water flow rate of the finned cooling coil. Q cool The adjustment of (t) determines the chilled water flow rate of the finned cooling coil. Q cool The formula for calculating (t) is: Q cool (t) = h ( Q water (t)); In the formula, h This refers to the heat transfer coefficient. h The following factors are mainly considered: 1. Material of finned cooling coils: Different materials such as copper, aluminum or stainless steel have different thermal conductivity, which will affect the efficiency of cold transfer.

[0027] 2. Structure and surface area of ​​finned cooling coils: The shape of the coil, the size and arrangement of the fins directly affect the cooling effect. The larger the surface area, the higher the cooling efficiency.

[0028] 3. Cold water flow rate: When the flow rate is high, the contact time between the cold water and the finned cooling coil is short, but the cooling efficiency can be improved by increasing the flow rate, although this may result in some hydraulic loss.

[0029] 4. Heat exchange efficiency: The heat exchange efficiency between cold water and heat sources (cables, pipes, etc.) has a significant impact on the transfer of cold energy.

[0030] For common finned cooling coils, the value of ℎ ranges from 0.1 to 2.0 kW / (L·min), depending on the specific design of the finned cooling coil and the cooling requirements.

[0031] S4: When Δ T cable (t)>threshold Δ T critical At that time, activate the linkage ventilation device and adjust the speed of the jet fan. Q fan (t) = g ( T room (t), Δ T cable (t))= K f Δ T room (t), K f This is the speed control constant for the jet fan.

[0032] In this embodiment, the threshold Δ T critical Mainly determined by cable surface temperature T cable (t), tunnel internal temperature T room (t), cable load P load (t) and cold water flow rate Q water (t) jointly determine. Threshold Δ T criticalSelect 80% of the design cold water flow rate (the current operating cold water flow rate of the system has reached 80% of the maximum design flow rate of the system), the deviation between the cable temperature and the set temperature is greater than 5℃, and 80% of the maximum cable load (the current being transmitted in the cable has reached 80% of the maximum safe current that the cable can withstand).

[0033] K f The ratio between temperature deviation and jet fan speed is controlled. If the setting is too large, the jet fan speed will react very quickly to temperature changes, potentially leading to frequent starts or over-adjustments, causing system instability or energy waste. If the setting is too small, the jet fan speed will react slowly, possibly failing to cool down quickly enough, resulting in a delayed system response. Larger environments (such as tunnels) are generally less sensitive to temperature changes, therefore... K f The value can be set between 0.1 and 1.0. This helps prevent the jet fan from over-responding.

[0034] S5: Real-time solution of the objective function based on optimization algorithms: Min (∑ t ( α ⋅Δ T cable (t) + β ⋅Δ T room (t) + gamma ⋅ Q water (t) + delta ⋅ Q fan (t))); In the formula, α , β , gamma , delta These are the weighting coefficients.

[0035] The control method in this embodiment adopts a multi-mode operation strategy: (1) Basic cooling: When the surface temperature of cable B reaches the first-level set temperature (e.g., 35 degrees), only the cold water circulation is turned on; (2) Enhanced cooling: When the surface temperature of cable B is between the first-level set temperature and the second-level set temperature (e.g., 35 degrees to 45 degrees), turn on the cold water circulation and intermittent ventilation; (3) Emergency cooling: When the surface temperature of cable B is higher than the secondary set temperature (e.g., greater than 45 degrees), the cooling water system will run at full power and the continuous ventilation system will be turned on at the same time.

[0036] The control algorithm in this embodiment is as follows: 1. Define system input: T_cable = get_cable_temperature() # Cable surface temperature; T_room = get_room_temperature() # Tunnel temperature; P_load = get_load() # Cable load; T_set = target_temperature() # Set the target temperature.

[0037] Calculate temperature deviation: delta_T_cable = T_cable - T_set; delta_T_room = T_room - T_set.

[0038] PID control of chilled water flow: Kp, Ki, Kd = 1.0, 0.1, 0.01; integral = integral + delta_T_cable + delta_T_room; derivative = delta_T_cable + delta_T_room - previous_error; water_flow = Kp * (delta_T_cable + delta_T_room) + Ki * integral + Kd* derivative.

[0039] Jet fan control: Kf = 0.5; fan_speed = Kf * delta_T_room.

[0040] 5. Cooling capacity control of coils: cooling_capacity = calculate_cooling_capacity(water_flow).

[0041] 6. Linkage control: if delta_T_cable > delta_T_threshold: fan_speed = max(fan_speed, calculate_linked_fan_speed(P_load)).

[0042] Optimize the objective function (based on energy consumption or temperature deviation): minimize_energy_and_temperature().

[0043] Output adjustment results: set_water_flow(water_flow); set_fan_speed(fan_speed); set_cooling_capacity(cooling_capacity).

[0044] The beneficial technical effects of this embodiment are as follows: 1. The vertical cooling curtain combined with the zoned circulation pipe network layout breaks through the limitations of traditional point cooling; 2. By integrating fiber optic temperature measurement and dynamic cooling distribution algorithms, meter-level temperature field control can be achieved; 3. Energy consumption is saved through the collaboration between the intelligent temperature control module and the cold water pipe network.

Claims

1. A smart cooling system for cable tunnels based on longitudinal zoning of cold water pipes, characterized in that... The cooling system includes a chilled water pipeline system, which consists of a primary water circulation system, a secondary water circulation system, and a plate heat exchanger. The primary water circulation system is located on both sides of the cable tunnel and includes a chiller, a primary circulating water pump, a chilled water supply main, and a chilled water return main. The inlet and outlet of the chilled water supply main are connected to the outlet of the primary circulating water pump and the inlet of the chilled water return main, respectively. The inlet and outlet of the chiller are connected to the outlet of the chilled water return main and the inlet of the primary circulating water pump, respectively. Both the chilled water supply main and the chilled water return main are arranged longitudinally along the cable tunnel. The cold water return main is arranged vertically relative to each other; the cable tunnel is divided into multiple areas along its longitudinal direction, and each area is equipped with a secondary water circulation system and a plate heat exchanger on both sides. The secondary water circulation system includes a first longitudinal pipe, a second longitudinal pipe, a first vertical pipe, a second vertical pipe, a first finned cooling coil, a second finned cooling coil, and a secondary circulating water pump. The secondary circulating water pump and the first finned cooling coil are both arranged on the first vertical pipe, and the second finned cooling coil is arranged on the second vertical pipe. The primary side of the plate heat exchanger is installed on the cold water supply main of the primary water circulation system, and the secondary side of the plate heat exchanger is installed on the second longitudinal pipe of the secondary water circulation system.

2. The intelligent cooling system for cable tunnels based on longitudinal zoning of cold water pipes as described in claim 1, characterized in that... The cable tunnel is equipped with a distributed optical fiber temperature measurement device along its longitudinal direction.

3. The intelligent cooling system for cable tunnels based on longitudinal zoning of cold water pipes as described in claim 2, characterized in that... The secondary circulating water pump is controlled by an intelligent temperature control device, and the distributed fiber optic temperature measurement device is communicatively connected to the intelligent temperature control device.

4. The intelligent cooling system for cable tunnels based on longitudinal zoning of cold water pipes as described in claim 3, characterized in that... The cooling system also includes a linkage ventilation device, which consists of a jet fan and an intelligent airflow adjustment system. The jet fan is controlled by the intelligent airflow adjustment system, which is communicatively connected to the intelligent temperature control device.

5. The intelligent cooling system for cable tunnels based on longitudinal zoning of cold water pipes as described in claim 4, characterized in that... The direction of the airflow from the jet fan is opposite to the direction of the water flow from the cold water supply main.

6. The intelligent cooling system for cable tunnels based on longitudinal zoning of cold water pipes as described in claim 1, characterized in that... The cold water supply main pipe is located at a certain distance below the cable support, and the cold water return main pipe is located at the top of the side wall of the cable trench.

7. The intelligent cooling system for cable tunnels based on longitudinal zoning of cold water pipes as described in claim 1, characterized in that... The water flow direction on the primary side of the plate heat exchanger is opposite to the water flow direction on the secondary side of the plate heat exchanger.

8. The working method of the intelligent cooling system for cable tunnels based on longitudinal partitioning of cold water pipes as described in any one of claims 1 to 7, characterized in that... The working method includes the following steps: S1: Real-time acquisition of cable surface temperature T cable (t), tunnel internal temperature T room (t), cable load P load (t); S2: Calculate cable surface temperature T cable (t) and the set target temperature T set The deviation Δ between T cable (t) and the temperature inside the tunnel T room (t) and the set target temperature T set The deviation Δ between T room (t): Δ T cable (t) = T cable (t)− T set ; Δ T room (t) = T room (t)− T set ; S3: Dynamically adjust the cold water flow rate of the secondary circulating water pump. Q water (t): Q water (t)= K p (Δ T cable (t)+Δ T room (t))+ K i ∫(Δ T cable (t)+Δ T room (t)) d t+ K d ( d (Δ T cable (t)+Δ T room (t)) / d t); In the formula, K p , K i , K d These are proportional, integral, and differential constants, which control the sensitivity, long-term deviation, and instantaneous change of the response, respectively. S4: When Δ T cable (t)>threshold Δ T critical At that time, activate the linkage ventilation device and adjust the speed of the jet fan. Q fan (t) = K f Δ T room (t), K f This is the control constant for the speed of the jet fan; S5: Real-time solution of the objective function based on optimization algorithms: Min (∑ t ( α ⋅Δ T cable (t) + β ⋅Δ T room (t) + γ ⋅ Q water (t) + δ ⋅ Q fan (t))); In the formula, α , β , γ , δ These are the weighting coefficients.

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