A non-shaft ventilation system for a middle part of an ultra-long underwater traffic tunnel and a ventilation method thereof

Abstract

The present application relates to a kind of super-long underwater traffic tunnel middle part vertical shaft-free ventilation system and ventilation method thereof, including right line tunnel, left line tunnel and intermediate tunnel, air supply room is provided with air supply fan, air supply room takes air through intermediate tunnel, it is sent to right line tunnel or left line tunnel using air supply outlet of air supply room export;Right line tunnel top air duct and left line tunnel top air duct are set up normal exhaust outlet in the air supply outlet upstream along the direction of travel, multiple interval setting parallel air duct will right line tunnel top air duct and left line tunnel top air duct be interconnected, fire smoke exhaust outlet is arranged at intercommunication, right line tunnel top air duct and left line tunnel top air duct are divided into multiple sections, and relay fan and blocking plate are arranged at each section, and each relay fan is arranged in independently excavated relay air duct.The present application does not need to set up ventilation vertical shaft in the middle of tunnel, realizes efficient ventilation and safe smoke exhaust function, significantly improves the reliability, economy and emergency response capability of tunnel operation.

Description

Technical Field

[0001] This invention belongs to the field of tunnel ventilation, and in particular relates to a ventilation system and ventilation method for the middle section of an ultra-long underwater traffic tunnel without vertical shafts. Background Technology

[0002] In the field of underwater highway tunnels, traditional ventilation systems primarily employ a segmented longitudinal ventilation method using vertical shafts, constrained by the geographical environment of rivers, lakes, and seas. This technology divides the tunnel into multiple ventilation sections by periodically installing ventilation shafts extending directly to the ground along its length, utilizing these shafts to introduce fresh air and exhaust waste gas. According to the "Detailed Design Code for Ventilation of Highway Tunnels," the maximum design wind speed inside a tunnel should not exceed 10.0 m / s; therefore, the length of each ventilation section must be strictly limited based on the required air volume. For ultra-long underwater tunnels, segmented ventilation is typically achieved by constructing artificial islands in the water and building vertical shafts, as seen in projects such as the immersed tunnel of the Hong Kong-Zhuhai-Macau Bridge. Furthermore, existing fire smoke extraction technologies mainly rely on the linkage between the smoke exhaust ducts at the tunnel ceiling and the vertical shafts, controlling the direction of smoke flow through longitudinal wind speed.

[0003] However, existing segmented vertical ventilation technology with shafts has the following drawbacks: First, the required air volume within the tunnel is directly proportional to its length. Limited by the maximum design wind speed (≤10.0 m / s), the length of the ventilation section is restricted, requiring multiple shafts for ultra-long tunnels. Second, long-distance ventilation leads to a dramatic increase in the installed power of the ventilation fans, resulting in high operating energy consumption. Third, vertical shafts in water areas require construction on artificial islands, which is difficult and costly, and also damages the aquatic ecosystem, affects navigation, and makes approval extremely difficult. Furthermore, when there are no shafts in the water section, the pressure inside the ventilation duct is extremely high due to the enclosed structure and ultra-long length of the underwater tunnel, leading to a significant increase in resistance and air leakage. Existing ventilation equipment is insufficient to meet smoke extraction requirements and cannot quickly and effectively remove smoke, seriously threatening personnel safety and the integrity of the tunnel structure. Therefore, existing technologies still have significant shortcomings in meeting the safety, energy-saving, and efficient ventilation and smoke extraction needs of ultra-long underwater tunnels. There is an urgent need for a new ventilation system that eliminates the need for a central shaft, adapts to the characteristics of ultra-long tunnels, and combines conventional ventilation with fire smoke extraction functions. Summary of the Invention

[0004] To address the aforementioned issues, this invention proposes a ventilation system and method for the central section of an ultra-long underwater traffic tunnel without a central shaft. This system eliminates the need for ventilation shafts in the tunnel, achieving efficient ventilation and safe smoke extraction, and significantly improving the reliability, economy, and emergency response capabilities of tunnel operation.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A shaftless ventilation system for the middle section of an ultra-long underwater traffic tunnel includes a right-line tunnel, a left-line tunnel, and a middle tunnel. The middle tunnel and either the right-line or left-line tunnel are connected by multiple spaced-apart air supply rooms. Each air supply room is equipped with an air supply fan. Air is drawn from the middle tunnel and supplied to the right-line or left-line tunnel via air outlets at the outlets of the air supply rooms. A right-line tunnel top ventilation duct is located at the top of each tunnel, and a left-line tunnel top ventilation duct is located at the top of each tunnel. Normal exhaust vents are located upstream of the air supply outlets in both the right-line and left-line tunnels along the direction of vehicle travel. Multiple spaced-apart parallel ventilation ducts connect the right-line tunnel top ventilation duct... The right and left tunnels are interconnected by the top ventilation duct, with fire exhaust vents provided at the connection points. Both the top ventilation ducts are divided into multiple sections, with a relay fan and a sealing plate installed at each section. Each relay fan is located in an independently excavated relay ventilation duct. The sealing plate is located inside the top ventilation ducts of both tunnels and has an openable / closable structure. When the relay fan is not running, the corresponding sealing plate is in the open ventilation duct state; when the relay fan is running, the corresponding sealing plate is in the closed ventilation duct state, forcing airflow to exit through the relay fan. Exhaust and smoke exhaust fans are installed at both ends of the right and left tunnels.

[0007] Preferably, the intermediate tunnel is the spare space at the bottom of an independent service tunnel, rescue tunnel, or vehicular tunnel.

[0008] Preferably, the distance between the air supply outlet and its corresponding normal exhaust outlet is greater than or equal to 50 meters.

[0009] Preferably, jet fans are installed in the right-line tunnel and the left-line tunnel along the direction of vehicle travel, and the jet fans are activated to suppress the backflow of smoke in case of fire.

[0010] Preferably, the inlet and outlet of the relay ventilation duct are located on opposite sides of the corresponding sealing plate.

[0011] Preferably, the inlet and / or outlet of the relay ventilation duct are equipped with baffles, and the baffles are linked with the sealing plate.

[0012] Preferably, the relay fan is a bidirectional fan that can switch the air supply direction according to control commands.

[0013] Preferably, the system includes a normal ventilation mode and a fire smoke extraction mode. In the normal ventilation mode, the operation of the fans is dynamically adjusted according to the traffic flow and pollutant concentration in the tunnel in the following order: only the exhaust and smoke extraction fans are turned on, some supply fans are added, some supply fans and relay fans are added, and all supply fans and relay fans are turned on.

[0014] Preferably, in the fire smoke exhaust mode, all supply fans are shut down, the nearest fire smoke exhaust vent downstream of the fire source is opened, and all relay fans and exhaust / smoke exhaust fans are turned on.

[0015] On the other hand, the present invention also discloses a ventilation method based on the above-mentioned ventilation system without vertical shafts in the middle of an ultra-long underwater traffic tunnel, including a normal ventilation operation mode and a fire smoke exhaust operation mode. The normal ventilation operation mode includes the following steps:

[0016] S11, turn on the air supply fan installed in the air supply fan room, take in air through the middle tunnel, and supply air to the right tunnel and left tunnel through the air supply port and normal exhaust port;

[0017] S12, turn on the relay fan set downstream of the ventilation fan along the direction of travel to guide the airflow to the end of the right tunnel and the left tunnel;

[0018] S13, turn on the exhaust and smoke exhaust fan to allow airflow to be discharged through the top ventilation duct of the right tunnel and the top ventilation duct of the left tunnel;

[0019] The fire smoke extraction operation mode includes the following steps:

[0020] S21, shut down all blowers;

[0021] S22, determine the location of the fire and open the nearest fire exhaust vent downstream of the fire source;

[0022] S23, turn on all relay fans and exhaust / smoke exhaust fans, and make the relay fans exhaust smoke from the left side to the left and the right side to the right of the fire point respectively.

[0023] Compared with the prior art, the advantages of the present invention are as follows:

[0024] (1) This invention achieves a closed-loop system layout for tunnel ventilation and smoke exhaust by setting up a ventilation room and air outlet in the middle tunnel and setting up an exhaust and smoke exhaust duct at the top of the vehicular tunnel. Combined with parallel ducts, relay fans and sealing plate control, it eliminates the need to set up ventilation shafts in the middle of the tunnel, avoiding the problems of high construction difficulty, high investment and difficult approval of traditional shafts in water areas, and significantly improving the feasibility and environmental adaptability of the project. The parallel ducts expand the smoke exhaust path from the conventional 2 to 4, improving the smoke exhaust efficiency.

[0025] (2) The present invention divides the ultra-long tunnel into multiple ventilation sections and configures relay fans, which effectively reduces the wind speed required for ventilation in each section, reduces ventilation resistance and fan energy consumption; at the same time, combined with traffic flow and pollutant concentration monitoring, the supply fan, relay fan and end exhaust fan can be dynamically started and stopped to achieve ventilation on demand, further reducing the overall operating energy consumption of the system;

[0026] (3) This invention utilizes the fire exhaust vent downstream of the fire source, the bidirectional controllable relay fan and the tunnel exhaust fan to form a longitudinal smoke exhaust flow field. The smoke can be partially discharged through the main line duct and partially guided to another tunnel through the parallel duct, effectively expanding the smoke exhaust channel and improving the smoke exhaust capacity, reliability and safety of the smoke exhaust system. Positive pressure jet fans are installed in the tunnel to form a pressure barrier to prevent smoke intrusion, greatly improving the efficiency of fire emergency response and the safety of personnel evacuation.

[0027] (4) The relay fan is located in an independently excavated ventilation duct and is linked to the top ventilation duct through a sealing plate. It can force the airflow when the fan is started and keep the ventilation duct unobstructed when the fan is turned off. This not only enhances the flexibility of operation control, but also avoids mutual interference of airflow at both ends of the ventilation duct, and improves the operational stability and maintenance convenience of the system.

[0028] (5) The installation of relay fans can effectively reduce the ventilation pressure in the duct and the pressure of each fan. The air leakage in the duct can be greatly reduced, effectively reducing the time for the smoke exhaust system to form a suction effect at the fire point. This makes the selection of fans in ultra-long-distance ducts feasible and solves the problem of smoke exhaust system failure caused by large duct resistance and air leakage in ultra-long-distance traffic tunnels without shafts, which makes it impossible to select fans. This significantly improves reliability and safety. Attached Figure Description

[0029] Figure 1 This is a schematic diagram illustrating the ventilation principle of a ventilation system without vertical shafts in the middle of an ultra-long underwater traffic tunnel, according to an embodiment of the present invention.

[0030] Figure 2 This is a schematic diagram illustrating the ventilation principle of the normal ventilation operation mode in an embodiment of the present invention.

[0031] Figure 3 This is a schematic diagram illustrating the ventilation principle of the fire smoke exhaust operation mode in an embodiment of the present invention.

[0032] Explanation of reference numerals in the attached diagram: 1-Right tunnel; 2-Middle tunnel; 3-Left tunnel; 4-Right tunnel top ventilation duct; 5-Left tunnel top ventilation duct; 6-Fire smoke exhaust vent; 7-Normal exhaust vent; 8-Supply fan; 9-Relay fan; 10-Relay ventilation duct; 11-Supply vent; 12-Parallel ventilation duct; 13-Exhaust and smoke exhaust fan; 14-Sealing plate. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention belong to the present invention.

[0034] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0035] Please see Figure 1-3 This embodiment discloses a shaftless ventilation system for the middle section of an ultra-long underwater traffic tunnel, including a right tunnel 1, a left tunnel 3, and a middle tunnel 2. The middle tunnel 2 and the right tunnel 1 or the left tunnel 3 are connected by multiple spaced ventilation rooms. Each ventilation room is equipped with a ventilation fan 8, which is used to supply fresh air to the vehicular tunnel. The ventilation room takes in air through the middle tunnel 2, that is, it uses the middle tunnel 2 as an air intake channel to avoid setting up a separate ventilation shaft structure. The air is delivered to the right tunnel 1 or the left tunnel 3 through the air outlet 11 at the outlet of the ventilation room. The air outlet 11 is the end interface for the ventilation fan 8 to introduce airflow into the tunnel. Its position is set on the tunnel wall or the ground to facilitate distributed air supply.

[0036] The top of the right tunnel 1 is equipped with a top ventilation duct 4, and the top of the left tunnel 3 is equipped with a top ventilation duct 5. The top ventilation ducts 4 and 5 correspond to the two vehicular tunnels and are used to collect and transport exhaust gas or smoke to the exhaust end. These two top ventilation ducts are interconnected by multiple parallel ventilation ducts 12 arranged at intervals. The arrangement of the parallel ventilation ducts 12 makes the top ventilation ducts of the two tunnels form a connected system with complementary air volume. A normal exhaust vent 7 is set upstream of the air supply vent 11 along the vehicular direction. The normal exhaust vent 7 is arranged below the ventilation duct and connected to the tunnel to extract exhaust gas and heat from inside the tunnel. A fire smoke exhaust vent 6 is set at the connection between the parallel ventilation duct 12 and the top ventilation duct. The fire smoke exhaust vent 6 is used to quickly exhaust smoke in the event of a fire and establish a cross-tunnel smoke exhaust channel with the help of the parallel ventilation duct 12 to improve smoke exhaust efficiency and redundancy.

[0037] Both the right-line tunnel top ventilation duct 4 and the left-line tunnel top ventilation duct 5 are divided into multiple sections. At each section, a relay fan 9 and a sealing plate 14 are installed. The relay fan 9 is used to enhance the airflow capacity within the ventilation duct, reduce system pressure loss and air leakage, and accelerate the formation time of effective airflow. The sealing plate 14 works in conjunction with the relay fan 9 to switch the ventilation duct connection status. Each relay fan 9 is located in an independently excavated relay ventilation duct 10, which serves as a dedicated passage for airflow through the relay fan 9. The top ventilation duct is isolated from the top ventilation duct. The sealing plate 14 is located inside the top ventilation duct 4 of the right tunnel and the top ventilation duct 5 of the left tunnel. It has an openable and closable structure. When the relay fan 9 is not started, the corresponding sealing plate 14 is in the open ventilation duct state, that is, the top ventilation duct is open and the airflow can pass through this section without obstruction. When the relay fan 9 is started, the corresponding sealing plate 14 is in the closed ventilation duct state, that is, the top ventilation duct is blocked and the airflow is forcibly guided to be discharged through the relay fan 9, so as to achieve directional pressurized exhaust.

[0038] Exhaust and smoke exhaust fans 13 are installed at both ends of the right tunnel 1 and the left tunnel 3. The exhaust and smoke exhaust fans 13 are used to extract air during normal ventilation. In the event of a fire, they serve as the terminal smoke exhaust power device and work with the relay fan 9 to form a longitudinal smoke exhaust flow field, thereby improving the overall performance of the system's ventilation and smoke exhaust.

[0039] Furthermore, intermediate tunnel 2 serves as a spare space at the bottom of an independent service tunnel, rescue tunnel, or vehicular tunnel. The structural form of intermediate tunnel 2 is not unique; it can be designed as a separate tunnel according to project needs, or it can be used to create a spare cross-section by reserving space under the vehicular tunnel. This intermediate tunnel 2 can be used to arrange relevant ventilation equipment, avoiding the need for ground-level shafts and improving the flexibility and adaptability of the ventilation system layout. The distance between the air supply outlet 11 and its corresponding normal exhaust outlet 7 is greater than or equal to 50 meters. Maintaining sufficient distance between the air supply outlet 11 and the exhaust outlet 7 prevents the supply airflow from being directly short-circuited and drawn away by the upper exhaust outlet 7, ensuring that the supply air covers a larger space in the tunnel, improving ventilation efficiency. By controlling the distance and coordinating with the segmented operation of the relay fan 9, the uniformity of airflow distribution and energy efficiency of the system can be achieved.

[0040] In addition, jet fans are installed along the vehicular direction in right tunnel 1 and left tunnel 3. In the event of a fire, the jet fans will be activated to suppress the backflow of smoke. The jet fans are installed at the top or sides of the tunnel and can generate sufficient longitudinal airflow in the event of a fire to establish a pressure barrier upstream of the fire source, suppressing the backflow of smoke in the opposite direction, thereby protecting the evacuation safety and the survival environment of personnel in the upstream area.

[0041] In this embodiment, the inlet and outlet of the relay ventilation duct 10 are located on both sides of the corresponding sealing plate 14. The relay ventilation duct 10 serves as a dedicated airflow channel connecting the inlet and outlet of the relay fan 9. Its two ends are respectively positioned before and after the sealing plate 14. When the sealing plate 14 is closed, airflow is guided into the relay ventilation duct 10 and pressurized by the relay fan 9 before being discharged. When the sealing plate 14 is open, the duct is open, the relay fan 9 does not participate in the ventilation process, and the airflow does not need to pass through the relay ventilation duct 10. Baffles are installed at the inlet and / or outlet of the relay ventilation duct 10, and these baffles are linked to the sealing plate 14. These baffles can open synchronously when the relay fan 9 is running and close when it is not running, cooperating with the sealing plate 14 to control the on / off state of the duct, ensuring that the airflow always follows a predetermined path under different operating conditions, avoiding turbulent flow and improving the controllability and stability of the system operation. The relay fan 9 is a bidirectional fan, capable of switching the ventilation direction according to control commands. The relay fan 9 has bidirectional operation capability. In the event of a fire, its operating direction can be controlled according to the location of the fire source. For example, the relay fan 9 on the left side of the fire point can blow air to the left, and the relay fan 9 on the right side can blow air to the right, thereby establishing an effective smoke exhaust channel downstream of the fire source, realizing the rapid and orderly discharge of smoke, and improving the flexibility and reliability of emergency smoke exhaust.

[0042] The ventilation system in this embodiment includes a normal ventilation mode and a fire smoke extraction mode. The normal ventilation mode is used for air circulation and pollutant dilution during the daily operation of the tunnel. Fresh air is introduced through the ventilation fan 8 in the middle tunnel 2, and airflow organization and exhaust are achieved by using components such as the right tunnel top duct 4, the left tunnel top duct 5, and the exhaust and smoke extraction fan 13. The fire smoke extraction mode is activated in the event of a fire. It achieves rapid smoke extraction and smoke control through a series of linked fans and duct components to ensure personnel evacuation and structural safety.

[0043] In normal ventilation operation mode, the operation of the fans is dynamically adjusted according to the traffic flow and pollutant concentration in the tunnel in the following order: only the exhaust and smoke exhaust fan 13 is turned on, some supply fans 8 are added, some supply fans 8 and relay fans 9 are added, and all supply fans 8 and relay fans 9 are turned on. By dynamically monitoring the air quality parameters in the tunnel, the exhaust and smoke exhaust fan 13 first draws air from both ends to establish a basic airflow; when the pollutant concentration increases, the supply fans 8 are gradually turned on to increase the air supply volume; when a larger ventilation coverage and wind speed are required, the relay fans 9 are gradually put into operation, dividing the ventilation system into multiple effective sections to improve efficiency and reduce energy consumption; finally, when the ventilation load is at its maximum, all fans are running, forming a stable and efficient longitudinal ventilation flow field.

[0044] In the fire smoke extraction mode, all supply fans 8 are shut down, the nearest fire smoke extraction vent 6 downstream of the fire source is opened, and all relay fans 9 and exhaust / smoke extraction fans 13 are activated. Shutting down the supply fans 8 prevents fresh air from spreading the fire source, and positioning the smoke extraction vent 6 downstream of the fire source facilitates the rapid extraction of high-temperature smoke. The relay fans 9 and exhaust / smoke extraction fans 13 form a longitudinal main smoke extraction channel, which, through its bidirectional operation, guides the smoke from the left and right sides of the fire source to the two end openings for discharge, improving smoke extraction efficiency and reducing the risk of smoke retention and backflow in the tunnel.

[0045] On the other hand, another embodiment of the present invention discloses a ventilation method based on the above-mentioned ventilation system without vertical shafts in the middle of an ultra-long underwater traffic tunnel, including a normal ventilation operation mode and a fire smoke exhaust operation mode. The ventilation method relies on the right tunnel 1, the left tunnel 3, the middle tunnel 2 and the components such as the air supply fan 8, the relay fan 9, the air supply outlet 11, the normal exhaust outlet 7, the fire smoke exhaust outlet 6, and the exhaust and smoke exhaust fan 13 installed on them to realize the automatic switching and efficient operation of daily ventilation and emergency smoke exhaust.

[0046] Please see Figure 2 The normal ventilation operation mode includes the following steps:

[0047] S11, turn on the air supply fan 8 located in the air supply room, draw air through the intermediate tunnel 2, and supply air to the right tunnel 1 and left tunnel 3 through the air supply outlet 11 and the normal exhaust outlet 7. The intermediate tunnel 2 serves as an air source channel, avoiding the need for a vertical shaft. After the air supply fan 8 introduces fresh air from the ground, it is delivered into the tunnel through the air supply outlet 11. The normal exhaust outlet 7 is located upstream of the air supply outlet 11 to avoid short-circuit effects and achieve effective airflow propulsion in the direction of vehicle travel.

[0048] S12, the downstream relay fan 9 of the blower 8 along the direction of travel is activated to guide the airflow to the ends of the right tunnel 1 and the left tunnel 3. The downstream relay fan 9 also includes the relay fan 9 corresponding to the other tunnel connected by the parallel air duct 12. The relay fan 9 pushes the airflow to extend to the far end of the tunnel through segmented pressurization, increasing the air supply length and ventilation zone control capability. At the same time, it works in conjunction with the linkage action of the sealing plate 14 to improve the system energy efficiency.

[0049] S13, turn on the exhaust and smoke extraction fan 13 to allow airflow to be discharged through the top ventilation duct 4 of the right tunnel and the top ventilation duct 5 of the left tunnel. The exhaust and smoke extraction fan 13 is located at both ends of the tunnel entrance, and together with the top ventilation duct, it forms a smooth longitudinal ventilation path, which can effectively remove pollutants and heat and maintain the air quality inside the tunnel.

[0050] Please see Figure 3 The fire smoke extraction operation mode includes the following steps:

[0051] S21, shut down all ventilation fans 8. Stopping ventilation during a fire prevents the accelerated spread of flames and smoke, and also prevents fresh air from carrying oxygen and aiding combustion.

[0052] S22, Determine the location of the fire and open the nearest fire exhaust vent 6 downstream of the fire source. The fire exhaust vent 6 quickly discharges the high-temperature toxic smoke through the nearest exhaust method, preventing the smoke from lingering in the central area.

[0053] S23, activate all relay fans 9 and exhaust / smoke exhaust fans 13, and ventilate smoke from the left and right sides of the fire point respectively. Relay fans 9 have bidirectional operation capability, allowing them to flexibly switch airflow direction according to the fire source location. Working in conjunction with exhaust / smoke exhaust fans 13, they simultaneously exhaust smoke in both directions. Meanwhile, parallel duct 12 provides a smoke exhaust path across the tunnel, significantly improving system smoke exhaust efficiency and fire response reliability.

[0054] In the fire smoke extraction mode, in addition to being discharged through the exhaust and smoke extraction fans 13 corresponding to the right tunnel 1 and left tunnel 3 respectively, the smoke can also be diverted from the top ventilation duct 4 of the right tunnel to the top ventilation duct 5 of the left tunnel via the parallel ventilation duct 12, or flow in the opposite direction, thus forming a two-way, two-channel smoke extraction system. Compared with the traditional layout that only relies on unidirectional smoke extraction at both ends of the line, the number of smoke extraction paths is doubled, improving the smoke evacuation capacity. By setting up relay fans 9, the air pressure and air leakage in the ventilation duct are reduced, improving reliability and safety. Relay fans 9 divide the ultra-long tunnel ventilation duct into segments, and each segment is driven by an independent fan to flow air, avoiding the high wind resistance problem caused by one-time supply and exhaust of the entire length of the ventilation duct, and reducing the system operating pressure; at the same time, the reduced air pressure can effectively reduce the air leakage at the joints and structures of the ventilation duct, ensuring that the airflow is delivered along the predetermined path.

[0055] In summary, this invention discloses a shaftless ventilation system and method for the middle section of an ultra-long underwater traffic tunnel. It utilizes the middle tunnel as the air intake channel, supplying air to the left and right vehicular tunnels via distributed fans and air outlets. Exhaust ventilation and smoke extraction are achieved through air ducts arranged at the tunnel top. Segmented control and airflow guidance are achieved through a combination of relay fans and sealing plates, and a cross-tunnel smoke extraction path is formed using parallel air ducts. This effectively realizes tunnel ventilation and emergency smoke extraction functions without the need for a middle shaft. The system features flexible structure, precise zone control, and low ventilation energy consumption. It improves the operational efficiency of ultra-long underwater tunnel ventilation systems and significantly enhances smoke extraction capacity and the reliability and safety of the ventilation system in the event of a fire. It is particularly suitable for engineering scenarios where shafts cannot be installed due to geographical, waterway, or waterway limitations. This invention overcomes the engineering constraints of segmented shaft ventilation in existing technologies, providing a safe, efficient, economical, and highly adaptable new ventilation solution for ultra-long underwater traffic tunnels, possessing significant engineering promotion value and industry demonstration significance.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Under the concept of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present invention as described above. For the sake of brevity, they are not provided in detail. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ventilation method for an ultra-long underwater traffic tunnel without a vertical shaft ventilation system in the middle, characterized in that, The ventilation system without vertical shafts in the middle of the ultra-long underwater traffic tunnel includes a right tunnel (1), a left tunnel (3), and a middle tunnel (2). The middle tunnel (2) and the right tunnel (1) or the left tunnel (3) are connected by multiple spaced ventilation rooms. Each ventilation room is equipped with a blower (8). The ventilation room draws air from the middle tunnel (2) and delivers it to the right tunnel (1) or the left tunnel (3) through the air outlet (11) at the outlet of the ventilation room. The top of the right tunnel (1) is equipped with a right tunnel top air duct (4), and the top of the left tunnel (3) is equipped with a left tunnel top air duct (5). The right tunnel top air duct (4) and the left tunnel top air duct (5) are equipped with normal exhaust outlets (7) upstream of the air outlet (11) along the vehicle direction. Multiple spaced parallel air ducts (12) connect the right tunnel top air duct (4) to the left tunnel top air duct (5). The right tunnel (1) and the left tunnel (5) are interconnected, and a fire exhaust vent (6) is provided at the interconnection point; the right tunnel (4) and the left tunnel (5) are divided into multiple sections, and a relay fan (9) and a sealing plate (14) are provided at each section. Each relay fan (9) is located in an independently excavated relay ventilation duct (10). The sealing plate (14) is located inside the right tunnel (4) and the left tunnel (5) and has an openable and closable structure. When the relay fan (9) is not started, the corresponding sealing plate (14) is in the open duct state; when the relay fan (9) is started, the corresponding sealing plate (14) is in the closed duct state, and the forced airflow is discharged through the relay fan (9); exhaust and smoke exhaust fans (13) are provided at the two ends of the right tunnel (1) and the left tunnel (3); The ventilation method for the ventilation system without vertical shafts in the middle of the ultra-long underwater traffic tunnel includes a normal ventilation mode and a fire smoke extraction mode. The normal ventilation mode includes the following steps: S11, turn on the blower (8) set in the blower room, take in air through the middle tunnel (2), and send air to the right tunnel (1) and the left tunnel (3) through the air supply port (11) and the normal exhaust port (7); S12, turn on the blower (8) and the relay blower (9) set downstream along the vehicle direction to guide the airflow to the end of the right tunnel (1) and the left tunnel (3); S13, turn on the exhaust and smoke exhaust fan (13) to allow the airflow to be discharged through the top ventilation duct (4) of the right tunnel and the top ventilation duct (5) of the left tunnel; The fire smoke extraction operation mode includes the following steps: S21, shut down all blowers (8); S22, determine the fire location and open the nearest fire exhaust vent downstream of the fire source (6); S23, turn on all relay fans (9) and exhaust fans (13), and make the relay fans (9) exhaust smoke in the direction from left to left and right to right of the fire point respectively; the relay fans (9) have bidirectional operation capability and can flexibly switch the wind direction according to the fire source location, and cooperate with the exhaust fans (13) to export smoke in both directions at the same time, while the parallel air duct (12) provides a smoke exhaust path across the tunnel.

2. The ventilation method for the mid-section of an ultra-long underwater traffic tunnel without a vertical shaft ventilation system according to claim 1, characterized in that, The intermediate tunnel (2) is the spare space at the bottom of an independent service tunnel, rescue tunnel, or vehicular tunnel.

3. The ventilation method for a shaftless ventilation system in the middle of an ultra-long underwater traffic tunnel according to claim 1 or 2, characterized in that, The distance between the air supply outlet (11) and its corresponding normal exhaust outlet (7) is greater than or equal to 50 meters.

4. The ventilation method for the middle section of an ultra-long underwater traffic tunnel without a vertical shaft ventilation system according to claim 3, characterized in that, Jet fans are installed in the right tunnel (1) and left tunnel (3) along the direction of vehicle travel. In case of fire, the jet fans are activated to suppress the backflow of smoke.

5. The ventilation method for the middle section of an ultra-long underwater traffic tunnel without a vertical shaft ventilation system according to claim 3, characterized in that, The inlet and outlet of the relay ventilation duct (10) are located on both sides of the corresponding sealing plate (14).

6. The ventilation method for the middle section of an ultra-long underwater traffic tunnel without a vertical shaft ventilation system according to claim 5, characterized in that, The inlet and / or outlet of the relay ventilation duct (10) are provided with baffles, which are linked with the sealing plate (14).

7. The ventilation method for the mid-section of an ultra-long underwater traffic tunnel without a vertical shaft ventilation system according to claim 6, characterized in that, The relay fan (9) is a bidirectional fan that can switch the ventilation direction according to control commands.

8. The ventilation method for the middle section of an ultra-long underwater traffic tunnel without a vertical shaft ventilation system according to claim 7, characterized in that, In the normal ventilation operation mode, the operation of the fans is dynamically adjusted according to the traffic flow and pollutant concentration in the tunnel in the following order: only the exhaust and smoke exhaust fan (13) is turned on, some supply fans (8) are added, some supply fans (8) and relay fans (9) are added, and all supply fans (8) and relay fans (9) are turned on.

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