Long shield tunnel smoke exhaust system and method based on smoke flue zoning and active suction-exhaust smoke vent

Abstract

The present application relates to a long and large shield tunnel smoke exhaust system and method based on a smoke flue zoning-active suction and exhaust type smoke exhaust port, which comprises an entrance fan room, an exit fan room, an active suction and exhaust type smoke exhaust module, a baffle, a communication air port and a jet fan; the smoke flue is divided into an entrance section, a middle section and an exit section in turn according to the traffic direction in the tunnel, and a normally open baffle is arranged between the two sections; each section of the smoke flue is connected with the tunnel space through the communication air port, the active suction and exhaust type smoke exhaust module is installed in the communication air port, the entrance fan room is connected with the entrance section through an air duct, the exit fan room is connected with the exit section through an air duct, the jet fan is installed in the tunnel, and the tunnel axial flow fan is installed at the entrance; under the safe working condition of the tunnel, the smoke flue cooperates with the fan room to ventilate the tunnel; under the tunnel fire smoke exhaust working condition, the fan room cooperates with the smoke flue to exhaust smoke from the tunnel. Compared with the prior art, the present application has the advantages of high smoke exhaust efficiency and reduced wind speed in the tunnel.

Description

Technical Field

[0001] This invention relates to the field of tunnel ventilation technology, and in particular to a smoke exhaust system and method for long shield tunnels based on smoke exhaust duct zoning and active suction and exhaust outlets. Background Technology

[0002] For extra-long highway tunnels, vertical (inclined) shaft ventilation is a common and effective solution. As tunnel length increases, the required air volume gradually increases, and the ventilation velocity inside the tunnel also increases. This results in increased ventilation resistance, significantly increased ventilation energy consumption, and decreased tunnel smoke extraction efficiency, leading to excessively high operating costs and mediocre results.

[0003] For example, the invention with publication number CN116658229A provides an integrated system and operation method for tunnel ventilation, purification, and smoke extraction. The system comprises a tunnel air supply channel, a tunnel exhaust and longitudinal smoke extraction channel, a tunnel purification exhaust channel, and a key tunnel smoke extraction channel. Its operation method includes four modes: tunnel ventilation, tunnel purification ventilation, key smoke extraction in shield tunnels, and longitudinal smoke extraction in open-cut tunnels. However, this structure still relies on vertical shaft installation.

[0004] For example, CN115163109A discloses a railway rescue station with a service tunnel and a method for personnel evacuation and smoke control. The railway rescue station includes a service tunnel, an evacuation cross passage, protective doors, smoke exhaust ducts, fireproof partitions, smoke exhaust fire dampers, fans, jet fans, smoke exhaust outlets, wind speed and direction sensors, and an evacuation platform. This solution requires the additional construction of a service passage and uses a one-way system, resulting in higher costs.

[0005] Therefore, researching new ventilation methods and scheduling techniques applicable to long highway tunnels that lack the conditions for installing ventilation shafts along the tunnel route or at tunnel entrances and exits is of great significance for ensuring the normal operation of long tunnels, optimizing ventilation design methods for long tunnels, improving smoke extraction efficiency of long tunnels, solving ventilation and smoke extraction problems in long tunnels, reducing ventilation velocity inside tunnels, improving the service quality of highway tunnels, and reducing the operating energy consumption of long highway tunnels. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art, such as high ventilation energy consumption, low smoke extraction efficiency, and high wind speed in long shield tunnels, which lead to high operating costs and mediocre ventilation and smoke extraction effects, and to provide a smoke extraction system and method for long shield tunnels based on smoke extraction duct partitioning and active suction and exhaust type smoke extraction outlets.

[0007] The objective of this invention can be achieved through the following technical solutions: This solution provides a smoke exhaust system for long shield tunnels based on smoke exhaust duct zoning and active suction and exhaust smoke exhaust outlets, including an inlet fan room, an outlet fan room, an active suction and exhaust smoke exhaust module, baffles, connecting air outlets, and jet fans; The smoke exhaust duct is divided into an entrance section, a middle section, and an exit section according to the traffic flow direction within the tunnel. A normally open baffle is installed between connecting sections. Each section of the smoke exhaust duct is connected to the tunnel space via connecting vents. The active suction and exhaust smoke exhaust module is installed at the connecting vents to actively draw smoke from the tunnel into the tunnel smoke exhaust duct. The entrance fan room is connected to the entrance section via a duct, and the exit fan room is connected to the exit section via a duct. The jet fan is installed inside the tunnel, and the tunnel axial flow fan is installed at the entrance. Under safe tunnel conditions, the smoke exhaust duct works in conjunction with the fan room for tunnel ventilation. Under tunnel fire smoke exhaust conditions, the fan room works in conjunction with the smoke exhaust duct for tunnel smoke extraction.

[0008] Furthermore, the active smoke extraction module includes a reversible fan, a smoke exhaust valve, and a flow guide hood; the smoke exhaust valve is installed on the side of the reversible fan near the tunnel to control the opening and closing of the smoke exhaust port, and the flow guide hood is installed on the side of the smoke exhaust valve near the tunnel to control the airflow pattern; there are multiple reversible fans, and each fan is distributed in an array.

[0009] Furthermore, the intermediate section is provided with an inclined partition, one end of which is close to the inlet section and the other end is close to the outlet section, dividing the intermediate section into a supply air distribution duct and an outlet air distribution duct. The supply air distribution duct is connected to the inlet section, and the connecting air outlet of the inlet section is located at the end of the supply air distribution duct near the outlet section; the outlet air distribution duct is connected to the outlet section, and the connecting air outlet of the outlet section is located at the end of the outlet air distribution duct near the inlet section.

[0010] This solution also provides a ventilation method for long shield tunnels, based on a smoke exhaust system for long shield tunnels with zoned smoke exhaust ducts and active suction and exhaust outlets. The ventilation method includes the following steps: Obtain traffic flow conditions inside the tunnel and compare them with a threshold; If the traffic flow in the tunnel is less than the threshold, only the jet fans in the tunnel will be turned on to make up the air. If the traffic flow in the tunnel is greater than or equal to the threshold, the axial flow fans in the entrance fan room and the exit fan room will be turned on. One axial flow fan will supply air into the tunnel, and the other axial flow fan will exhaust the air in the tunnel. The baffle near the air supply connection air outlet will be closed, and the tunnel axial flow fan will be turned on at the same time.

[0011] Furthermore, the intermediate section is equipped with a partition plate inclined along the axial direction of the smoke exhaust duct, dividing the entire smoke exhaust duct into an extended supply air duct and an extended outlet air duct. The connecting air outlet of the extended supply air duct is located at one end near the outlet section, and the connecting air outlet of the extended outlet air duct is located at one end near the entrance section. The wind speed inside the tunnel is obtained and compared with a wind speed threshold. If the actual wind speed inside the tunnel is greater than or equal to the wind speed threshold, the entire tunnel space adopts overall alternating supply and exhaust circulation ventilation, including the following steps: Turn on the tunnel axial flow fans, as well as the axial flow fans in the inlet and outlet fan rooms; turn on the active smoke extraction module. Polluted air near the entrance of the tunnel is drawn into the extended exhaust duct by the active smoke extraction module, transported along the exhaust duct, and discharged through the outlet fan room. The active smoke extraction module in the extended air supply duct reverses, sending fresh air into the tunnel near the exit section; The jet fan, in conjunction with the traffic wind, discharges another portion of the polluted gas from the tunnel exit, thus achieving tunnel ventilation.

[0012] Furthermore, if the traffic flow inside the tunnel is greater than or equal to a threshold, the left and right driving spaces of the tunnel will both utilize overall circulating ventilation, including the following steps: Turn on the tunnel axial flow fans and the axial flow fans in the inlet and outlet fan rooms, and close the baffle between the inlet section and the intermediate section. The axial flow fan in the inlet fan room supplies air into the tunnel through the connecting air vent in the inlet section, and the axial flow fan in the outlet fan room discharges a portion of the polluted gas from the tunnel through the connecting air vent in the outlet section. The jet fan, in conjunction with the traffic wind, discharges another portion of the polluted gas from the tunnel exit, thus achieving tunnel ventilation.

[0013] Furthermore, if the traffic flow inside the tunnel is greater than or equal to a threshold, the left and right driving spaces of the tunnel will be ventilated using the nearest exhaust ventilation method, including the following steps: Turn on the tunnel axial flow fans and the axial flow fans in the inlet and outlet fan rooms, and close the baffle between the inlet section and the intermediate section. The axial flow fan in the entrance fan room exhausts the gas in the tunnel through the connecting air vent in the entrance section, while the axial flow fan in the exit fan room supplies air into the tunnel through the connecting air vent in the exit section.

[0014] Furthermore, if the traffic flow inside the tunnel is greater than or equal to a threshold, the driving space on the left side of the tunnel will use overall recirculation ventilation, while the driving space on the right side of the tunnel will use local exhaust ventilation, including the following steps: Turn on the tunnel axial flow fans that use overall circulating ventilation in the left driving space, as well as the axial flow fans in the entrance fan room and the exit fan room, and close the baffle between the left entrance section and the middle section. The axial flow fan in the left entrance fan room supplies air into the tunnel through the connecting air vent in the entrance section, and the axial flow fan in the left exit fan room discharges some of the polluted gas in the tunnel through the connecting air vent in the exit section. At the same time, the tunnel axial flow fan in the right-side driving space that uses the nearest exhaust ventilation, as well as the axial flow fans in the entrance fan room and the exit fan room, are turned on, and the baffle between the right-side entrance section and the middle section is turned off. The axial flow fan in the right-side entrance fan room exhausts the gas in the tunnel through the connecting air vent in the entrance section, while the axial flow fan in the right-side exit fan room supplies air into the tunnel through the connecting air vent in the exit section.

[0015] This solution also provides a smoke extraction method for long shield tunnels, based on a smoke extraction duct zone-active suction and exhaust type smoke extraction outlet smoke extraction system for long shield tunnels. The smoke extraction method includes the following steps: Determine the location of the fire; Close the baffle at one end of the middle section of the smoke exhaust duct and turn on the active suction and exhaust smoke exhaust module to actively draw the fire smoke into the smoke exhaust duct and store the smoke in the smoke exhaust duct. After the tunnel evacuation and rescue operation is completed, the axial flow motor in the fan room connected to the smoke exhaust duct is turned on to discharge the smoke from the duct.

[0016] Furthermore, axial flow motors are installed at the entrance and exit of the tunnel respectively. When a fire is detected in the tunnel and the location of the fire is determined, the operation mode of the fans in the tunnel is further adjusted.

[0017] Furthermore, the smoke extraction process, which involves adjusting the operation of the ventilation fans within the tunnel based on the location of the fire, includes: When a fire occurs at the corresponding smoke exhaust duct outlet section inside the tunnel, shut down the jet fans inside the tunnel and the axial flow fans at the tunnel entrance, while maintaining the normal rotation of the axial flow fans at the tunnel exit. Close the baffle on one side of the exit section and open the active suction and exhaust smoke module in the connecting air vent of the exit section of the smoke exhaust duct to draw the smoke into the smoke exhaust duct while assisting the smoke to be discharged from the tunnel exit end. When a fire occurs at the corresponding smoke exhaust duct inlet section inside the tunnel, shut down the jet fan inside the tunnel and the axial fan at the tunnel exit, and reverse the rotation of the axial fan at the tunnel inlet. Close the baffle on one side of the entrance section and open the active suction and exhaust smoke module in the connecting air vent of the entrance section of the smoke exhaust duct to draw the smoke into the smoke exhaust duct while assisting the smoke to be discharged from the tunnel entrance. When a fire occurs in the middle section of the smoke exhaust duct inside the tunnel, the jet fan inside the closed tunnel and the axial fan at the tunnel entrance are kept rotating in the forward direction, while the axial fan at the tunnel entrance is rotated in the reverse direction. Keep the baffles on both sides of the middle section open, and open the active suction and exhaust smoke modules in the connecting air vents of the inlet and outlet sections of the smoke exhaust duct to draw the smoke into the smoke exhaust duct while assisting the smoke to be discharged from both ends of the tunnel.

[0018] Compared with the prior art, the present invention has the following advantages: (1) The longitudinal ventilation scheme of segmented ventilation and smoke exhaust in this invention utilizes axial flow fans, jet fans and axial flow fans in the fan room connected to the smoke exhaust duct installed in the tunnel, in conjunction with corresponding control equipment. Under normal tunnel operation conditions, the smoke exhaust duct can be used to supplement air in the tunnel space, reduce the wind speed in the tunnel space, reduce the ventilation resistance in the tunnel, and reduce the energy consumption of tunnel operation. Moreover, it solves the problem of excessive wind speed or even exceeding the limit in the tunnel space when it is inconvenient to set up ventilation shafts in the longitudinal ventilation of long tunnels, thus creating conditions for ventilation of long highway tunnels without setting up ventilation shafts.

[0019] (2) This invention utilizes a ventilation system to guide fire smoke and stores the smoke based on the smoke exhaust duct. This reduces the problem of excessive smoke spread distance during tunnel fire smoke exhaust, which makes it difficult to exhaust the smoke and affects rescue and evacuation. It can reduce the impact of smoke on the tunnel space and provide time and space for evacuation and rescue.

[0020] (3) The active suction exhaust port proposed in this invention, through the installation of a suction fan, an openable and closable exhaust valve and a guide hood, realizes the active suction of smoke in the tunnel, improves the exhaust efficiency and smoke control capability of the exhaust port, and solves the problem of insufficient suction power of the tunnel exhaust port.

[0021] (4) The overall device of the present invention does not require the construction of additional ventilation shafts (towers), which reduces the difficulty of site selection and planning, reduces the impact of tunnels on the surrounding environment, reduces the scale of civil engineering and engineering costs, and is conducive to saving design. It has certain practical value and application prospects. Attached Figure Description

[0022] Figure 1 A schematic diagram of a tunnel where both the left and right driving spaces are ventilated by a unified circulating system, as provided by the present invention. Figure 2 A schematic diagram of the tunnel provided by the present invention, in which both the left and right driving spaces adopt the overall alternating supply and exhaust circulation ventilation; Figure 3 The diagram provided by this invention shows that the left and right driving spaces of the tunnel are both ventilated by exhausting the air from the nearest source. Figure 4 A schematic diagram of a tunnel where both left and right driving spaces are equipped with combined ventilation, as provided by the present invention. Figure 5 A diagram illustrating the smoke extraction pattern when a fire occurs within a long exhaust duct section, provided by this invention. Figure 6 A smoke exhaust pattern diagram provided by the present invention when a fire occurs in a short smoke exhaust section; Figure 7 This is a structural schematic diagram of a single fan provided by the present invention; Figure 8 This is a schematic diagram of the array fan provided by the present invention; Figure 9 This is a schematic diagram of the structure of the flue provided by the present invention; Figure 10 This is a schematic diagram of a tunnel ventilation segmentation method and airflow provided in this embodiment; Figure 11 This is a schematic diagram of a tunnel smoke exhaust method provided in an embodiment. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0025] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0026] Example 1 like Figure 1 As shown, this embodiment provides a smoke exhaust system for long shield tunnels based on smoke exhaust duct partitioning and active suction and exhaust smoke exhaust outlets, including an inlet fan room, an outlet fan room, an active suction and exhaust smoke exhaust module, baffles, connecting air outlets, and jet fans; The smoke exhaust duct is divided into an entrance section, a middle section, and an exit section according to the traffic flow direction within the tunnel. A normally open baffle is installed between connecting sections. Each section of the smoke exhaust duct is connected to the tunnel space via connecting vents. The active suction and exhaust smoke exhaust module is installed at the connecting vents to actively draw smoke from the tunnel into the tunnel smoke exhaust duct. The entrance fan room is connected to the entrance section via a duct, and the exit fan room is connected to the exit section via a duct. The jet fan is installed inside the tunnel, and the tunnel axial flow fan is installed at the entrance. Under safe tunnel conditions, the smoke exhaust duct works in conjunction with the fan room for tunnel ventilation. Under tunnel fire smoke exhaust conditions, the fan room works in conjunction with the smoke exhaust duct for tunnel smoke extraction.

[0027] In this embodiment, as Figure 7 As shown, the active smoke extraction module includes a reversible fan, a smoke extraction valve, and a flow guide hood. The smoke extraction valve is installed on the side of the reversible fan closest to the tunnel and is used to control the opening and closing of the smoke extraction port. The flow guide hood is installed on the side of the smoke extraction valve closest to the tunnel and is used to control the airflow pattern.

[0028] Optional, such as Figure 8 As shown, there are multiple forward and reverse fan arrays.

[0029] In this embodiment, for fire smoke exhaust conditions, to reduce the spread of smoke and allow it to be stored within the smoke exhaust duct, thereby improving the smoke collection capacity of the exhaust outlet, an active suction and exhaust type smoke exhaust outlet is installed at the top of the tunnel. Depending on the required pressure, the exhaust outlet is equipped with a reversible fan or a fan array containing multiple fans. An openable and closable smoke exhaust valve is installed outside the fan to control the opening and closing of the exhaust outlet, and a guide hood is installed to control the airflow pattern. Baffles are installed in the tunnel smoke exhaust duct. The shape and area of ​​the baffles are determined by the actual shape and area of ​​the tunnel smoke exhaust duct. The baffles are controlled by the control center and are normally in an unfolded state. Their opening and closing can be controlled by various methods such as side-pull, folding, push-pull, and rotation. They are installed at designated locations within the tunnel smoke exhaust duct. Under specified fire conditions, upon receiving a signal from the control center, the mobile device can respond quickly to open and close the tunnel smoke exhaust duct baffles.

[0030] The system also includes a control center, which consists of a series of sensors for temperature, wind speed, and pollutants, monitoring equipment, electromechanical equipment, computers, and corresponding software platforms deployed within the tunnel. This control center can monitor the tunnel's operational status and, based on data transmitted from within the tunnel, control the operation of axial and jet fans. Furthermore, the control center can provide early warnings of fires within the tunnel, identifying whether a fire has occurred and its location, and generating different responses based on the actual fire situation, controlling the operation of the tunnel's smoke exhaust fans and the opening and closing of the tunnel's baffles.

[0031] Without constructing ventilation towers (shafts), under operational ventilation conditions, it can reduce cross-sectional wind speed within the tunnel, reduce ventilation energy consumption, enhance ventilation effect, and lower tunnel operating costs. In fire smoke extraction conditions, smoke can be stored in the smoke extraction duct, and active suction and exhaust smoke outlets can be used to draw the smoke into the duct nearby, ensuring smoke control during personnel evacuation and providing a solution for long-distance smoke extraction in tunnels.

[0032] This embodiment also provides a ventilation method for a smoke exhaust system in a long shield tunnel based on a zoned smoke exhaust duct and an active suction and exhaust smoke exhaust outlet, such as... Figure 1 , Figure 3 and Figure 4 As shown, for operational ventilation conditions, ventilation can be achieved using the smoke exhaust duct within the tunnel. The smoke exhaust duct is located in the upper part of the tunnel space, dividing it into three sections. Baffles are installed in corresponding sections within the smoke exhaust duct. These baffles have both unfolded and folded states, and their opening and closing can be controlled by the control center. Under normal circumstances, they are in the unfolded state. Connecting air vents and air diversion devices to the tunnel space are installed at the corresponding sections within the smoke exhaust duct. Fan rooms are located at both ends of the tunnel smoke exhaust duct, connected to the duct via air ducts. Axial flow fans are installed in the fan rooms. Jet fans are installed within the tunnel space.

[0033] During routine tunnel ventilation, when traffic volume is low, only the jet fans inside the tunnel can be turned on for supplementary air. When traffic volume is high and vehicles move slowly, and jet fans alone cannot meet the ventilation requirements, axial fans operate normally, delivering a portion of fresh air from the tunnel entrance into the tunnel space. In addition to the axial fans, the axial fans located at both ends of the exhaust duct operate under the control of the control center. The axial fans near the tunnel entrance deliver fresh air into the exhaust duct, and then through the connecting vents between the exhaust duct and the tunnel space, they are delivered into the tunnel space for supplementary air. The axial fans near the tunnel exit start operating, creating negative pressure in the exhaust duct, expelling the air from the exhaust duct. At the same time, some polluted gas in the tunnel is drawn into the exhaust duct through the connecting vents, while the remaining gas is discharged from the tunnel exit under the action of traffic airflow and jet fan airflow, thus achieving the discharge of polluted gas from the rear section of the tunnel.

[0034] When there is a usable underground working shaft in the middle of the tunnel, the underground working shaft can be renovated to set up a fan room. The fan room is connected to the smoke exhaust duct through a duct. An axial flow fan is installed in the fan room. This fan plays a relay role. If the fan is close to the entrance, it will guide some fresh air into the tunnel space when it is running. If the fan is close to the exit, it will guide some polluted air in the tunnel space into the smoke exhaust duct and exhaust it from the smoke exhaust duct. The rest will be discharged from the tunnel entrance.

[0035] This embodiment also provides a smoke extraction method for a long shield tunnel smoke extraction system based on the above-mentioned smoke extraction duct zoning-active suction and exhaust type smoke extraction outlet, such as... Figure 5 and Figure 6 As shown, during ventilation and smoke extraction in a tunnel under fire conditions, the active suction and exhaust smoke vents are opened to actively draw smoke from the tunnel into the tunnel smoke duct, thereby reducing the length of smoke spread and improving smoke extraction efficiency. The tunnel smoke duct stores fire smoke and prevents it from entering the tunnel space. The tunnel smoke duct should provide an appropriate volume to ensure that the ratio of volume to the designed smoke extraction capacity meets the time requirements for tunnel evacuation and rescue. After the rescue is completed, the smoke in the smoke duct is discharged through the smoke vents, ventilation towers, etc.

[0036] Depending on the location of the fire, the operating mode of each axial flow fan also varies.

[0037] When a fire occurs near the tunnel exit, the axial flow fans installed in the middle section of the tunnel and at the entrance stop operating, while the axial flow fans at the tunnel exit operate normally. The baffles installed in the tunnel's smoke exhaust duct remain closed, and the fire smoke is discharged from the exit.

[0038] When a fire occurs near the tunnel entrance, the axial flow fans installed in the middle section of the tunnel and at the exit stop operating, while the axial flow fans at the tunnel entrance reverse, and the fire smoke is discharged from the entrance.

[0039] In the event of a fire in the middle section of the tunnel, the baffles installed in the tunnel's smoke exhaust duct open, the axial flow fans at the tunnel exit and the middle working shaft rotate forward, and the axial flow fans at the tunnel entrance rotate in reverse. The fire smoke is then discharged from both ends of the tunnel through the tunnel's smoke exhaust duct, thus achieving smoke extraction under tunnel fire conditions.

[0040] Example 2 This embodiment is basically the same as Embodiment 1, except that, as Figure 2 and Figure 9 As shown, in this embodiment, an inclined partition is provided in the middle section of the flue. One end of the partition is close to the inlet section and the other end is close to the outlet section, dividing the middle section into a supply air distribution duct and an outlet air distribution duct. The supply air distribution duct is connected to the inlet section, and the connecting air outlet of the inlet section is located at the end of the supply air distribution duct near the outlet section. The outlet air distribution duct is connected to the outlet section, and the connecting air outlet of the outlet section is located at the end of the outlet air distribution duct near the inlet section.

[0041] By using diverter plates inclined along the axial direction of the exhaust duct, the entire exhaust duct is divided into an extended supply duct and an extended outlet duct. During normal tunnel operation, the wind speed inside the tunnel is acquired and compared with a wind speed threshold. If the actual wind speed inside the tunnel is greater than or equal to the wind speed threshold, the entire tunnel space adopts overall alternating supply and exhaust circulation ventilation, including the following steps: Turn on the tunnel axial flow fans, as well as the axial flow fans in the inlet and outlet fan rooms; turn on the active smoke extraction module. Polluted air near the entrance of the tunnel is drawn into the extended exhaust duct by the active smoke extraction module, transported along the exhaust duct, and discharged through the outlet fan room. The active smoke extraction module in the extended air supply duct reverses, sending fresh air into the tunnel near the exit section; The jet fan, in conjunction with the traffic wind, discharges another portion of the polluted gas from the tunnel exit, thus achieving tunnel ventilation.

[0042] By dividing the exhaust duct into intersecting extended supply air ducts and extended outlet air ducts using partitions, the extended outlet air duct actively draws in polluted air from the tunnel entrance section, while the outlet of the extended supply air duct supplies air to the tunnel entrance section and reduces the wind speed inside the tunnel. This ventilation regulation method can effectively reduce the tunnel ventilation wind speed and improve the service quality of highway tunnels.

[0043] Example 3 This embodiment is basically the same as Embodiment 1, except that, as Figure 10 and Figure 11 As shown in the figure, this embodiment takes an underwater shield tunnel as an example to introduce the calculation method for operational ventilation and smoke extraction using a smoke exhaust duct.

[0044] (1) Basic information about the tunnel According to the engineering design data and relevant specifications, the values ​​of the basic tunnel conditions are shown in Table 1.

[0045] Table 1 Basic Calculation Parameters of the Tunnel

[0046] (2) Calculation of required air volume Based on the basic parameters and traffic conditions, the required air volume calculated using the PIARC 2019 standard and the "Detailed Rules for Ventilation of Highway Tunnels" is shown in the figure, and the design is carried out with a 10-year lag. Meanwhile, considering the requirements for air exchange rates in the 2014 "Detailed Rules", the calculated air volume for the near, medium, and long term is shown in Table 2.

[0047] Table 2 Calculation Results of Required Air Volume

[0048] (3) Ventilation segmentation method The next step will be to calculate the ventilation scheme using a smoke exhaust duct, dividing the smoke exhaust duct into three equal sections, such as... Figure 8As shown, the lengths are L1, L2, and L3, and the airflow organization within the tunnel is correspondingly divided into three sections. The required fresh air volume for the tunnel is divided into two parts: one part enters from the tunnel entrance with a volume of Q1, and the other part enters from the ventilation shaft S1 with a volume of Q2. Q2 = 129m³ is selected. 3 / s, Q1=627m 3 / s.

[0049] (4) Required pressure increase inside the tunnel The design is based on the required air volume and ventilation segmentation method. The calculation methods for the friction resistance coefficient, local loss coefficient, inlet and outlet pressure loss coefficient, and pressure rise are based on the "Detailed Rules" 2014. The calculation results of ventilation resistance, traffic wind force, and required pressure rise in the tunnel are shown in Table 3.

[0050] Table 3 Calculation results of pressure rise

[0051] (5) Fan layout scheme Based on the pressure rise calculation results and smoke exhaust requirements, the calculated fan configuration is shown in Table 4. Table 4 Fan Configuration Results

[0052] (6) Calculation of smoke exhaust volume and stored smoke volume Based on the plume model and a 50MW fire scenario in a tunnel with one-way traffic, the minimum smoke extraction volume required for the cut-and-cover section to completely remove all smoke generated by the fire is 191.12m³. 3 / s, the minimum smoke extraction rate required for the shield tunnel section is 185.44m³ / s. 3 / s. Therefore, the exhaust air volume is taken as 220m³ / s. 3 / s. The exhaust gas pressure is approximately 2900 Pa. The flue gas organization scheme is as follows: Figure 9 As shown, each group of exhaust fans consists of 3 units, with a total of 9 fans installed along the entire line, two in operation and one on standby. Each fan has an exhaust capacity of 110 m³ / h. 3 / s, total pressure approximately 2900Pa. Taking the most unfavorable location in the event of a fire (at the right-side partition), the fire smoke is stored in the tunnel's smoke exhaust duct and then discharged. The evacuation and rescue time provided by drawing in and filling the smoke exhaust duct can be calculated as follows: Tunnel smoke exhaust duct volume Vp = 210,359.8m³ 3 Based on a smoke emission volume of 220m³ 3 Based on the calculation, the time required to fill the smoke duct is t=956.2s, which provides a rescue duration of over 15 minutes. After the rescue is completed, the active smoke exhaust fan reverses to completely expel the smoke.

[0053] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A ventilation and smoke extraction method for long shield tunnels based on smoke exhaust duct zoning and active suction and exhaust smoke outlets, comprising a ventilation and smoke extraction system, characterized in that, The ventilation and smoke exhaust system includes an inlet fan room, an outlet fan room, an active suction and exhaust smoke exhaust module, baffles, connecting air outlets, and jet fans; The exhaust duct is divided into an entrance section, a middle section, and an exit section according to the traffic flow direction in the tunnel, and a normally open baffle is installed between two connected sections. Each section of the exhaust duct is connected to the tunnel space through a connecting air vent. The active suction and exhaust smoke exhaust module is installed at the connecting air vent and is used to actively draw smoke from the tunnel into the tunnel exhaust duct. The entrance fan room is connected to the entrance section through a duct, and the exit fan room is installed in the exit section through a duct. The jet fan is installed inside the tunnel. Under safe tunnel operating conditions, the exhaust duct works in conjunction with the fan room for tunnel ventilation. The ventilation method includes the following steps: Obtain traffic flow conditions inside the tunnel and compare them with a threshold; If the traffic flow in the tunnel is less than the threshold, only the jet fans in the tunnel will be turned on to make up the air. If the traffic flow in the tunnel is greater than or equal to the threshold, the axial flow fans in the entrance fan room and the exit fan room will be turned on. One axial flow fan will supply air into the tunnel, and the other axial flow fan will exhaust the air in the tunnel. The baffle near the air supply and connection air outlet will be closed, and the tunnel axial flow fan will be turned on at the same time. The left and right driving spaces of the tunnel will adopt overall circulation ventilation, or the left and right driving spaces of the tunnel will adopt local exhaust ventilation, or the driving space on the left side of the tunnel will adopt overall circulation ventilation, and the driving space on the right side of the tunnel will adopt local exhaust ventilation. In the case of smoke extraction during a tunnel fire, the fan room works in conjunction with the smoke extraction duct to extract smoke from the tunnel. The smoke extraction method includes the following steps: Determine the location of the fire; Close the baffle at one end of the middle section of the smoke exhaust duct and turn on the active suction and exhaust smoke exhaust module to actively draw the fire smoke into the smoke exhaust duct and store the smoke in the smoke exhaust duct. After the tunnel evacuation and rescue operation is completed, the axial flow motor in the fan room connected to the smoke exhaust duct is turned on to discharge the smoke from the duct.

2. The ventilation and smoke extraction method for long shield tunnels based on smoke exhaust duct zoning and active suction and exhaust smoke outlets as described in claim 1, characterized in that, The active smoke extraction module includes a reversible fan, a smoke extraction valve, and a flow guide. The smoke extraction valve is installed on the side of the reversible fan closest to the tunnel and is used to control the opening and closing of the smoke extraction port. The flow guide is installed on the side of the smoke extraction valve closest to the tunnel and is used to control the airflow pattern. There are multiple reversible fans, and each fan is distributed in an array.

3. A ventilation and smoke extraction method for long shield tunnels based on smoke exhaust duct zoning and active suction / exhaust smoke outlets, as described in claim 2, is characterized in that... The intermediate section is equipped with an inclined partition, with one end of the partition near the inlet section and the other end near the outlet section, dividing the intermediate section into a supply air distribution duct and an outlet air distribution duct. The supply air distribution duct connects to the inlet section, and the connecting air outlet of the inlet section is located at the end of the supply air distribution duct near the outlet section. The outlet air distribution duct connects to the outlet section, and the connecting air outlet of the outlet section is located at the end of the outlet air distribution duct near the inlet section.

4. The ventilation and smoke extraction method for long shield tunnels based on smoke exhaust duct zoning and active suction and exhaust smoke outlets as described in claim 1, characterized in that, If the traffic flow inside the tunnel is greater than or equal to the threshold, the left and right driving spaces of the tunnel will both adopt overall circulating ventilation, including the following steps: Turn on the tunnel axial flow fans and the axial flow fans in the inlet and outlet fan rooms, and close the baffle between the inlet section and the intermediate section. The axial flow fan in the inlet fan room supplies air into the tunnel through the connecting air vent in the inlet section, and the axial flow fan in the outlet fan room discharges a portion of the polluted gas from the tunnel through the connecting air vent in the outlet section. The jet fan, in conjunction with the traffic wind, discharges another portion of the polluted gas from the tunnel exit, thus achieving tunnel ventilation.

5. A ventilation and smoke extraction method for long shield tunnels based on smoke exhaust duct zoning and active suction / exhaust smoke outlets, as described in claim 1, is characterized in that... If the traffic flow inside the tunnel is greater than or equal to the threshold, the left and right driving spaces of the tunnel will be ventilated by exhausting the nearest available airflow, including the following steps: Turn on the tunnel axial flow fans and the axial flow fans in the inlet and outlet fan rooms, and close the baffle between the inlet section and the intermediate section. The axial flow fan in the entrance fan room exhausts the gas in the tunnel through the connecting air vent in the entrance section, while the axial flow fan in the exit fan room supplies air into the tunnel through the connecting air vent in the exit section.

6. A ventilation and smoke extraction method for long shield tunnels based on smoke exhaust duct zoning and active suction / exhaust smoke outlets, as described in claim 1, is characterized in that... If the traffic flow inside the tunnel is greater than or equal to the threshold, the driving space on the left side of the tunnel will use overall circulation ventilation, while the driving space on the right side of the tunnel will use local exhaust ventilation, including the following steps: Turn on the tunnel axial flow fans that use overall circulating ventilation in the left driving space, as well as the axial flow fans in the entrance fan room and the exit fan room, and close the baffle between the left entrance section and the middle section. The axial flow fan in the left entrance fan room supplies air into the tunnel through the connecting air vent in the entrance section, and the axial flow fan in the left exit fan room discharges some of the polluted gas in the tunnel through the connecting air vent in the exit section. At the same time, the tunnel axial flow fan in the right-side driving space that uses the nearest exhaust ventilation, as well as the axial flow fans in the entrance fan room and the exit fan room, are turned on, and the baffle between the right-side entrance section and the middle section is turned off. The axial flow fan in the right-side entrance fan room exhausts the gas in the tunnel through the connecting air vent in the entrance section, while the axial flow fan in the right-side exit fan room supplies air into the tunnel through the connecting air vent in the exit section.

7. A ventilation and smoke extraction method for long shield tunnels based on smoke exhaust duct zoning and active suction / exhaust smoke outlets, as described in claim 1, is characterized in that... The intermediate section is equipped with a partition plate inclined along the axial direction of the smoke exhaust duct, dividing the entire smoke exhaust duct into an extended supply air duct and an extended outlet air duct. The connecting air outlet of the extended supply air duct is located at one end near the outlet section, and the connecting air outlet of the extended outlet air duct is located at one end near the entrance section. The wind speed inside the tunnel is obtained and compared with a wind speed threshold. If the actual wind speed inside the tunnel is greater than or equal to the wind speed threshold, the entire tunnel space adopts overall alternating supply and exhaust circulation ventilation, including the following steps: Turn on the tunnel axial flow fans, as well as the axial flow fans in the inlet and outlet fan rooms; turn on the active smoke extraction module. Polluted air near the entrance of the tunnel is drawn into the extended exhaust duct by the active smoke extraction module, transported along the exhaust duct, and discharged through the outlet fan room. The active smoke extraction module in the extended air supply duct reverses, sending fresh air into the tunnel near the exit section; The jet fan, in conjunction with the traffic wind, discharges another portion of the polluted gas from the tunnel exit, thus achieving tunnel ventilation.

8. A ventilation and smoke extraction method for long shield tunnels based on smoke exhaust duct zoning and active suction / exhaust smoke outlets, as described in claim 1, is characterized in that... Axial flow motors are installed at both the entrance and exit of the tunnel. When a fire is detected in the tunnel and the location of the fire is determined, the operation mode of the fans inside the tunnel is further adjusted, including the following steps: When a fire occurs at the corresponding smoke exhaust duct outlet section inside the tunnel, shut down the jet fans inside the tunnel and the axial flow fans at the tunnel entrance, while maintaining the normal rotation of the axial flow fans at the tunnel exit. Close the baffle on one side of the exit section and open the active suction and exhaust smoke module in the connecting air vent of the exit section of the smoke exhaust duct to draw the smoke into the smoke exhaust duct while assisting the smoke to be discharged from the tunnel exit end. When a fire occurs at the corresponding smoke exhaust duct inlet section inside the tunnel, shut down the jet fan inside the tunnel and the axial fan at the tunnel exit, and reverse the rotation of the axial fan at the tunnel inlet. Close the baffle on one side of the entrance section and open the active suction and exhaust smoke module in the connecting air vent of the entrance section of the smoke exhaust duct to draw the smoke into the smoke exhaust duct while assisting the smoke to be discharged from the tunnel entrance. When a fire occurs in the middle section of the smoke exhaust duct inside the tunnel, the jet fan inside the tunnel and the axial fan at the tunnel entrance are kept rotating in the forward direction, while the axial fan at the tunnel entrance is rotated in the reverse direction. Keep the baffles on both sides of the middle section open, and open the active suction and exhaust smoke modules in the connecting air vents of the inlet and outlet sections of the smoke exhaust duct to draw the smoke into the smoke exhaust duct while assisting the smoke to be discharged from both ends of the tunnel.

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