Extra-high voltage long-distance cable tunnel ventilation system and cable tunnel

Abstract

The utility model relates to the technical field of cable tunnel ventilation, and provides an extra-high voltage long-distance cable tunnel ventilation system and a cable tunnel, the extra-high voltage long-distance cable tunnel ventilation system comprises a plurality of ventilation subsystems which are sequentially arranged along the length direction of the tunnel, a first firewall is arranged between two adjacent ventilation subsystems, and a second firewall is arranged between two adjacent ventilation subsystems. Each ventilation subsystem comprises an air feeder, an exhaust fan and n fireproof sections sequentially arranged in the tunnel in the length direction of the tunnel, n is an integer larger than or equal to 3 and smaller than or equal to 5, and every two adjacent fireproof sections in each ventilation subsystem are communicated through a normally-open fireproof door. The air feeder and the exhaust fan are arranged at the two ends of the tunnel section where the ventilation subsystem is located in the length direction correspondingly and communicate with the tunnel section and the outside correspondingly. The number of fans used is reduced, the construction difficulty is reduced, the construction cost is saved, and the economical efficiency and the reliability of cable tunnel ventilation can be both considered on the whole.

Description

A ventilation system for ultra-high voltage long-distance cable tunnels and the cable tunnel itself. Technical Field

[0001] This utility model relates to the field of cable tunnel ventilation technology, specifically to a ventilation system for ultra-high voltage long-distance cable tunnels and a cable tunnel. Background Technology

[0002] Cable tunnels are underground tubular structures used for the centralized laying of high-voltage power cables. They are a special type of urban underground utility tunnel. Cable tunnels not only better protect the cables but also facilitate cable inspection and maintenance. Because power cables, especially ultra-high-voltage cables, release a large amount of heat during operation, ventilation systems are required to quickly cool them and prevent electrical fires.

[0003] Currently, to ensure safer and more reliable fire protection for cable tunnels, fire-resistant zones are typically established, for example, every 200 meters. Related technologies involve designating a ventilation system for each fire-resistant zone, requiring ventilation shafts every 200 meters on the ground. This large number of shafts increases construction difficulty, project costs, and significantly impacts the surrounding landscape. Furthermore, it increases the number of fans used, raising the complexity of the ventilation system and reducing its operational economy and reliability. Simultaneously, excessively increasing the length of fire-resistant zones not only results in excessively powerful fans with noise pollution affecting the environment and higher daily operating costs, but also increases the potential losses in the event of an electrical fire. Summary of the Invention

[0004] The technical problem to be solved by this utility model is: how to balance the economy and reliability of cable tunnel ventilation.

[0005] This utility model provides a ventilation system for ultra-high voltage long-distance cable tunnels, including multiple ventilation subsystems arranged sequentially along the tunnel length. A first firewall is provided between two adjacent ventilation subsystems. Each ventilation subsystem includes a supply fan, an exhaust fan, and n fire-resistant sections arranged sequentially along the tunnel length, where n is an integer greater than or equal to 3 and less than or equal to 5. Two adjacent fire-resistant sections within each ventilation subsystem are connected by normally open fire doors. The supply fan and the exhaust fan are respectively located at both ends of the tunnel section where the ventilation subsystem is located and are respectively connected to the tunnel section and the outside.

[0006] Optionally, n is 4.

[0007] Optionally, a second firewall is provided between two adjacent fire-resistant sections within each ventilation subsystem, and the normally open fire door is located on the second firewall.

[0008] Optionally, two adjacent ventilation subsystems are arranged in opposite directions along the length of the tunnel.

[0009] Optionally, the supply fan and the exhaust fan are respectively connected to the tunnel through pipes, and a first fire damper is installed at the pipe connected to the supply fan, and a second fire damper is installed at the pipe connected to the exhaust fan.

[0010] Optionally, the triggering temperature of the second fire damper is higher than that of the first fire damper.

[0011] Optionally, gravity check valves are respectively installed in the pipes connected to the blower and the pipes connected to the exhaust fan.

[0012] Optionally, the ventilation subsystem further includes ventilation shafts for installation on the ground, with the two ventilation shafts respectively connected to the supply fan and the exhaust fan, and the top of the ventilation shaft is provided with a cover, and the side wall of the ventilation shaft is provided with a ventilation opening, with rainproof louvers provided inside the ventilation opening.

[0013] Optionally, the ventilation subsystem further includes a temperature detector and a gas concentration detector, both of which are installed inside the tunnel.

[0014] Compared with the prior art, the ventilation system for ultra-high voltage long-distance cable tunnels provided by this utility model has the following technical effects:

[0015] The ventilation system for long-distance ultra-high voltage cable tunnels provided by this utility model can be applied to ventilation, cooling, and fire prevention in cable tunnels, especially for long-distance high-voltage and ultra-high-voltage cable tunnels with multiple fire compartments. By arranging multiple ventilation subsystems along the tunnel length, with each subsystem spanning 3 to 5 fire compartments, each fire compartment can serve as a fire compartment within the cable tunnel and is connected by normally open fire doors. During application, the supply and exhaust fans at both ends of the ventilation subsystem's length create a circulating airflow, improving ventilation and providing continuous ventilation and cooling within the cable tunnel. Furthermore, if an electrical fire occurs in a fire compartment, the corresponding normally open fire doors can be closed to prevent damage to other fire compartments. Simultaneously, by setting up a first firewall between adjacent ventilation subsystems, each subsystem becomes an independent ventilation system, preventing mutual interference and significantly reducing the severity of electrical fire hazards. By implementing the above structural design, each ventilation subsystem spans multiple fire zones, thus reducing the number of fans required, simplifying construction, and lowering construction costs. This approach does not significantly impact the surrounding landscape. Furthermore, by selecting subsystems that span a certain number of fire zones (3 to 5 fire zones per system), not only are ventilation efficiency and safety guaranteed, but the reliability and stability of the ventilation system are also ensured. Overall, this approach balances the economic efficiency and reliability of cable tunnel ventilation.

[0016] In addition, this utility model also provides a cable tunnel, including the above-mentioned ventilation system for ultra-high voltage long-distance cable tunnels.

[0017] Compared with the prior art, the cable tunnel provided by this utility model has roughly the same technical effect as the above-mentioned ventilation system for ultra-high voltage long-distance cable tunnels by setting up an ultra-high voltage long-distance cable tunnel ventilation system, and will not be described in detail here. Attached Figure Description

[0018] Figure 1 is a schematic diagram of the working principle of the ventilation system for ultra-high voltage long-distance cable tunnels according to an embodiment of this utility model.

[0019] Explanation of reference numerals in the attached figures:

[0020] 1-First firewall, 2-Supply fan, 3-Exhaust fan, 4-Fire compartment, 5-Normally open fire door, 6-Second firewall, 7-First fire damper, 8-Second fire damper, 9-Gravity check valve, 10-Ventilation shaft, 11-Rainproof louver. Detailed Implementation

[0021] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0022] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this utility model described herein can be implemented in sequences other than those illustrated or described herein.

[0023] In the description of this utility model, the orientation or positional relationship indicated by terms such as "up", "down", "left", "right", "top", "bottom", "front", "back", "inner" and "outer" is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing this utility model and is not intended to indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the scope of protection of this utility model.

[0024] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0025] In the description of this specification, references to terms such as "embodiment," "one embodiment," and "one implementation" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or implementation is included in at least one embodiment or illustrative embodiment of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or implementation. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or implementations.

[0026] To solve the above-mentioned technical problems, as shown in Figure 1, this utility model embodiment provides a ventilation system for ultra-high voltage long-distance cable tunnels, including multiple ventilation subsystems arranged sequentially along the tunnel length direction. A first firewall 1 is provided between two adjacent ventilation subsystems. Each ventilation subsystem includes a supply fan 2, an exhaust fan 3, and n fireproof sections 4 arranged sequentially along the tunnel length direction within the tunnel, where n is an integer greater than or equal to 3 and less than or equal to 5. Two adjacent fireproof sections 4 within each ventilation subsystem are connected by normally open fire doors 5. The supply fan 2 and the exhaust fan 3 are respectively located at both ends of the tunnel section where the ventilation subsystem is located, and are respectively connected to the tunnel section and the outside.

[0027] It should be noted that the working mode of the blower 2 is to draw in outside air and blow it into the tunnel, while the working mode of the exhaust fan 3 is to exhaust the gas in the tunnel to the outside. As shown in Figure 1, the solid arrow indicates the wind direction when the ventilation system of this ultra-high voltage long-distance cable tunnel is working. At the same time, both the blower 2 and the exhaust fan 3 can be selected as dual-speed fans, that is, they have two working modes: high speed and low speed. They can be controlled remotely, wired or manually to meet the needs of different working conditions. For example, if conventional cooling and ventilation are required in the tunnel, the low-speed mode can be selected to save energy, reduce costs and further improve its economy. If rapid cooling is required in the tunnel, or rapid removal of smoke or harmful gases generated by electrical fires, the high-speed mode can be selected to quickly ventilate or cool, improve work efficiency and reliability.

[0028] Meanwhile, each ventilation subsystem has the same composition, and the specific number of subsystems can be designed according to actual construction needs, such as the length of the cable tunnel and fire prevention and ventilation requirements. This UHV long-distance cable tunnel ventilation system is especially suitable for ventilation operations in long-distance, UHV cable tunnels. Compared with existing technologies, it can save construction costs and improve reliability to a greater extent. In this context, fire protection section 4 refers to a fire protection zone set up within the cable tunnel. That is, one fire protection section 4 represents one fire protection zone within the cable tunnel. The length of fire protection section 4 is set according to the length of the fire protection zone within the cable tunnel. Generally, according to existing urban integrated pipe gallery fire prevention and ventilation specifications, the length of a fire protection zone is typically 200 meters. This embodiment, in accordance with these specifications, sets up a ventilation subsystem spanning 3 to 5 fire protection sections 4, resulting in better ventilation economy and reliability. The number of fire protection sections 4 spanning a single section can be determined by establishing a mathematical model using simulation software and performing mesh generation. Boundary conditions such as meteorological parameters and material property parameters are set, and theoretical models such as mass conservation, momentum conservation, energy conservation, and turbulence equations are used for iterative simulation calculations. The velocity and temperature distribution under different ventilation unit lengths are analyzed to determine the optimal length of the ventilation unit in the UHV tunnel, i.e., to obtain the optimal number n of fire protection sections 4 within a ventilation subsystem.

[0029] Preferably, the number of fire-resistant sections 4 in each ventilation subsystem is 4, and the designed ventilation unit length is the most reasonable and reliable. This reduces the number of components such as fans, saves construction costs and reduces construction difficulty, and also ensures the overall ventilation safety and reliability.

[0030] In this embodiment, the ventilation system for long-distance ultra-high voltage cable tunnels provided can be applied to ventilation, cooling, and fire prevention in cable tunnels, especially for long-distance high-voltage and ultra-high-voltage cable tunnels with multiple fire compartments. Multiple ventilation subsystems are arranged along the tunnel length, with each subsystem spanning 3 to 5 fire compartments 4. Each fire compartment 4 serves as a fire compartment within the cable tunnel and is connected by normally open fire doors 5. During application, circulating airflow is formed by supply fans 2 and exhaust fans 3 located at both ends of the ventilation subsystem's length, improving ventilation efficiency and providing continuous ventilation and cooling within the cable tunnel. Furthermore, if an electrical fire occurs in a fire compartment 4, the corresponding normally open fire door 5 can be closed to prevent it from harming other fire compartments 4. Simultaneously, by setting up a first firewall 1 between adjacent ventilation subsystems, each subsystem becomes an independent ventilation system, preventing mutual interference and significantly reducing the severity of electrical fire hazards. By implementing the above structural design, each ventilation subsystem spans multiple fire zones, thus reducing the number of fans required, simplifying construction, and saving costs. Furthermore, it minimizes the impact on the surrounding landscape. By selecting subsystems that span a certain number of fire zones (3 to 5 fire zones per subsystem), ventilation efficiency and safety are ensured, along with the reliability and stability of the ventilation system. Overall, this approach balances the economic efficiency and reliability of cable tunnel ventilation.

[0031] Optionally, as shown in Figure 1, a second firewall 6 is provided between two adjacent fire protection sections 4 in each ventilation subsystem, and the normally open fire door 5 is provided on the second firewall 6.

[0032] Specifically, the normally open fire door 5 is located in the middle of the second firewall 6, which allows for more uniform and smooth ventilation. The opening direction of the normally open fire door 5 is set according to the ventilation direction in the tunnel, that is, the direction indicated by the solid arrow in Figure 1, which is the direction from the supply fan 2 to the exhaust fan 3, making the structure more reasonable and reliable.

[0033] In this embodiment, by setting a second firewall 6 between two adjacent fire protection sections 4 in each ventilation subsystem, if an electrical fire occurs in a certain fire protection section 4, the corresponding normally open fire door 5 can be closed, and the second firewall 6 will separate the two adjacent fire protection sections 4, that is, it will not affect the adjacent fire protection sections 4, thus further ensuring the overall safety and reliability.

[0034] Optionally, as shown in Figure 1, two adjacent ventilation subsystems are arranged in opposite directions along the length of the tunnel.

[0035] Specifically, the two adjacent ventilation subsystems are arranged in opposite directions along the length of the tunnel, or they are arranged symmetrically. That is, the supply fan 2 ends of the two adjacent ventilation subsystems are arranged close to each other, or the exhaust fan 3 ends of the two adjacent ventilation subsystems are arranged close to each other.

[0036] In this embodiment, by arranging two adjacent ventilation subsystems in opposite directions along the length of the tunnel, that is, the air supply fan 2 of one ventilation subsystem is next to the air supply fan 2 of the next ventilation subsystem, and the exhaust fan 3 of the ventilation subsystem is next to the exhaust fan 3 of the adjacent ventilation subsystem, hot air or smoke and dust generated by electrical fires discharged from one ventilation subsystem to the outside is prevented from entering the tunnel where the adjacent ventilation subsystem is located. This avoids mutual interference between the two adjacent ventilation subsystems during ventilation operations, improves the overall safety and reliability, and also improves ventilation efficiency.

[0037] Optionally, as shown in Figure 1, the supply fan 2 and the exhaust fan 3 are respectively connected to the tunnel through pipes. A first fire damper 7 is installed at the pipe connected to the supply fan 2, and a second fire damper 8 is installed at the pipe connected to the exhaust fan 3.

[0038] Specifically, fire dampers are key safety devices in building fire protection systems, primarily used to block the spread of fire and smoke within ventilation ducts during a fire. Their working principle involves two triggering mechanisms: one is that a temperature-sensitive element (such as a 70℃ or 280℃ fuse) automatically melts at high temperatures, mechanically driving the valve leaf to close; the other is that it receives an electrical signal from the fire protection system, causing an electric actuator to forcibly close it. The first fire damper 7 and the second fire damper 8 can be designed and selected according to actual operating conditions.

[0039] In this embodiment, by installing a first fire damper 7 at the ventilation fan 2, in the event of an electrical fire in the tunnel section, the first fire damper 7 can effectively block its connection with the outside world, preventing the fire from spreading and intensifying. That is, it can prevent fresh air from continuing to enter the section, effectively slowing down the fire. At the same time, by installing a second fire damper 8 at the exhaust fan 3, the fire can also be prevented from spreading, that is, preventing the flames and toxic fumes in the section from spreading to other areas. This allows for the segmented shut-off of the ventilation system, minimizing losses, preventing cascading effects, and further improving the overall safety and reliability.

[0040] Optionally, as shown in the figure, the triggering temperature of the second fire damper 8 is higher than that of the first fire damper 7.

[0041] For example, the first fire damper 7 has a trigger temperature of 70°C and is a 70°C fire damper. It has functions such as fusible shut-off when the temperature reaches 70°C, manual shut-off, 24V electrical signal shut-off, electric reset, manual reset, and outputting an open or closed status signal. The second fire damper 8 has a trigger temperature of 280°C and is a 280°C fire damper. It has functions such as fusible shut-off when the temperature reaches 280°C, manual shut-off, 24V electrical signal shut-off, electric reset, manual reset, and outputting an open or closed status signal.

[0042] In this embodiment, by setting the trigger temperature of the second fire damper 8 to be higher than that of the first fire damper 7, that is, the temperature of the gas discharged from the exhaust end of a ventilation subsystem can be higher than the temperature of the gas entering from the inlet end, under the premise of ensuring segmented isolation and preventing the spread of fire, in the event of an electrical fire, the high-temperature gas or smoke in the segment can be effectively discharged, which is conducive to subsequent personnel entering for maintenance and repair, making the whole system more reasonable and reliable.

[0043] Optionally, as shown in Figure 1, gravity check valves 9 are respectively installed in the pipes connected to the blower 2 and the pipes connected to the exhaust fan 3.

[0044] Specifically, the gravity check valve is a valve that relies on the fluid's own gravity and backflow pressure to achieve one-way shut-off, which can effectively prevent gas backflow during ventilation or when the fan is stationary. The gravity check valves 9 at the supply fan 2 and exhaust fan 3 can be of the same model, or can be designed to adapt to the fan.

[0045] In this embodiment, by installing gravity check valves 9 in the pipes connected to the blower 2 and the exhaust fan 3 respectively, backflow or turbulence of gas in the tunnel can be effectively prevented, ensuring the smoothness and reliability of overall ventilation and further improving ventilation efficiency.

[0046] Optionally, as shown in Figure 1, the ventilation subsystem further includes ventilation shafts 10 installed on the ground. The two ventilation shafts 10 are respectively connected to the supply fan 2 and the exhaust fan 3. The top of the ventilation shaft 10 is provided with a cover, and the side wall of the ventilation shaft 10 is provided with a ventilation opening. A rainproof louver 11 is provided inside the ventilation opening.

[0047] Specifically, the lower end of the ventilation shaft 10 can be connected to the blower 2 and the exhaust fan 3 through a channel under the ground. The ventilation openings on the side walls of the ventilation shaft 10 are equipped with rainproof louvers 11, which are similar to louver structures, to prevent rainwater or foreign objects from entering the ventilation shaft 10. Preferably, an insect-proof net structure can also be installed at the ventilation openings to prevent insects or other foreign objects from entering the ventilation system and avoid affecting the ventilation system.

[0048] In this embodiment, ventilation shaft 10, which is connected to the blower 2 and the exhaust fan 3, is set on the ground to improve ventilation. Furthermore, by opening ventilation openings on the side wall of the ventilation shaft, installing rainproof louvers 11 inside the ventilation openings, and sealing the top of the ventilation shaft, rainwater is prevented from entering the ventilation shaft 10, thus preventing external rainwater and other foreign objects from affecting the ventilation system and further improving the overall reliability.

[0049] Optionally, as shown in Figure 1, the ventilation subsystem further includes a temperature detector and a gas concentration detector, both of which are installed inside the tunnel.

[0050] Specifically, the temperature detector can be a temperature sensor, and the gas concentration detector can be a sensor used to detect, for example, the concentration of toxic fumes generated by electrical fires. Both can be connected to, for example, a controller. If the temperature is higher than a certain threshold, or the corresponding gas concentration is higher than a certain threshold, the blower 2 and exhaust fan 3 and other components can be remotely controlled to perform corresponding operations, which facilitates the improvement of intelligence and automation.

[0051] In this embodiment, by installing temperature detectors and gas concentration detectors inside the tunnel, effective and reliable parameters of temperature and gas concentration within the tunnel can be provided to the ventilation system, facilitating automated control of the ventilation system. For example, when the temperature inside the tunnel is low, ventilation operations can be suspended, saving energy and costs. If the temperature is higher than a certain level, ventilation and cooling operations can be initiated. Simultaneously, if an electrical fire occurs in the tunnel, generating smoke, the gas concentration detectors can detect the corresponding changes. On one hand, this can provide an alert, and on the other hand, the ventilation system can be immediately shut down via remote control. After handling an accident, the monitoring results of the gas concentration detectors can be used to determine whether it is suitable for manual entry for maintenance operations, further improving overall safety and reliability.

[0052] In addition, another embodiment of this utility model provides a cable tunnel, including the above-mentioned ventilation system for ultra-high voltage long-distance cable tunnels.

[0053] For example, the cable tunnel is a long-distance, ultra-high voltage cable tunnel.

[0054] In this embodiment, the cable tunnel provided by this embodiment, by setting up the above-mentioned UHV long-distance cable tunnel ventilation system, has roughly the same technical effect as the above-mentioned UHV long-distance cable tunnel ventilation system, and will not be described again here.

[0055] Although the present invention has been disclosed above, its protection scope is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the protection scope of the present invention.

Claims

1. A ventilation system for ultra-high voltage long-distance cable tunnels, characterized in that, The system includes multiple ventilation subsystems arranged sequentially along the length of the tunnel. A first firewall (1) is provided between two adjacent ventilation subsystems. Each ventilation subsystem includes a supply fan (2), an exhaust fan (3), and n fire-resistant sections (4) arranged sequentially along the length of the tunnel. The n is an integer greater than or equal to 3 and less than or equal to 5. Two adjacent fire-resistant sections (4) in each ventilation subsystem are connected by normally open fire doors (5). The supply fan (2) and the exhaust fan (3) are respectively located at both ends of the tunnel section where the ventilation subsystem is located and are respectively connected to the tunnel section and the outside. The supply fan (2) and the exhaust fan (3) are respectively connected to the inside of the tunnel through pipes. Gravity check valves (9) are respectively provided in the pipes connected to the supply fan (2) and the pipes connected to the exhaust fan (3).

2. The ventilation system for ultra-high voltage long-distance cable tunnels according to claim 1, characterized in that, The value of n is 4.

3. The ventilation system for ultra-high voltage long-distance cable tunnels according to claim 1, characterized in that, A second firewall (6) is provided between two adjacent fire protection sections (4) in each ventilation subsystem, and the normally open fire door (5) is provided on the second firewall (6).

4. The ventilation system for ultra-high voltage long-distance cable tunnels according to claim 1, characterized in that, The two adjacent ventilation subsystems are arranged in opposite directions along the length of the tunnel.

5. The ventilation system for ultra-high voltage long-distance cable tunnels according to claim 1, characterized in that, A first fire damper (7) is installed at the pipe connected to the blower (2), and a second fire damper (8) is installed at the pipe connected to the exhaust fan (3).

6. The ventilation system for ultra-high voltage long-distance cable tunnels according to claim 5, characterized in that, The triggering temperature of the second fire damper (8) is higher than that of the first fire damper (7).

7. The ventilation system for ultra-high voltage long-distance cable tunnels according to claim 1, characterized in that, The ventilation subsystem also includes ventilation shafts (10) for installation on the ground. The two ventilation shafts (10) are connected to the blower (2) and the exhaust fan (3) respectively. The top of the ventilation shaft (10) is provided with a cover. The side wall of the ventilation shaft (10) is provided with a ventilation opening. The ventilation opening is provided with a rainproof louver (11).

8. The ventilation system for ultra-high voltage long-distance cable tunnels according to claim 1, characterized in that, The ventilation subsystem also includes a temperature detector and a gas concentration detector, both of which are installed inside the tunnel.

9. A cable tunnel, characterized in that, Including the ventilation system for ultra-high voltage long-distance cable tunnels as described in any one of claims 1-8.

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