Shield tunnel waste gas purification system and method

Abstract

The invention relates to a shield tunnel waste gas purification system and method.The system comprises a purification device, an air inlet shutter, an air outlet shutter, an introduction pipe, an air outlet pipe and a transverse air pipe, the purification device is arranged in a box culvert on the lower portion of a shield tunnel roadway, the air inlet shutter and the air outlet shutter are arranged on the side wall of the roadway, and one end of the introduction pipe is connected with the air inlet shutter; one end of the air outlet pipe is connected with the input end of the purification device through a transverse air pipe, the other end of the air outlet pipe is connected with the input end of the purification device through a transverse air pipe, and one end of the air outlet pipe is connected with the output end of the purification device through a transverse air pipe while the other end of the air outlet pipe is connected with the air outlet shutter; opening or closing of the loop is controlled through the arranged electric air valves, and a purification fan is arranged in the fan loop. The purification device is arranged on the lower portion of the traveling crane plate, the operation states of the bypass loop and the fan loop are dynamically adjusted and controlled in combination with the air volume of the piston, and efficient treatment and energy-saving purification operation of sinking particle pollution are achieved.

Description

Technical Field

[0001] This invention relates to the field of tunnel ventilation and purification, specifically to a shield tunnel exhaust gas purification system and method. Background Technology

[0002] In recent years, with the increasing development of urban underground space, shield tunneling has gradually become the main construction method for urban rail transit and municipal integrated passages. Exhaust gases generated during train operation and particulate pollutants accumulated within the tunnel structure continue to build up in the enclosed space. Therefore, purifying the air inside the tunnel has become a crucial aspect of ensuring operational safety and improving ventilation quality. Existing shield tunnel exhaust gas purification systems typically employ the method of directly installing purification equipment on the tunnel roof or sidewalls. Fans force polluted air to be drawn into filter or adsorption modules to treat particulate matter and harmful gases. These systems generally follow the traditional mechanical ventilation approach, with fans and purification modules mostly fixed installations, and the treated air is then discharged back into the tunnel through ducts.

[0003] In practical engineering, ventilation and purification units are often quite large, occupying not only space in the upper or side walls of the tunnel but also requiring operating space for equipment maintenance and operation. Furthermore, existing systems only extract exhaust gas from the upper space and are not designed to adapt to the dynamic airflow characteristics of piston winds within shield tunnels. In the operating environment of shield tunnels, large particles in the exhaust gas typically settle downwards due to gravity and accumulate continuously in the lower tunnel area. This makes top or side extraction purification methods ineffective in treating descending contaminants, thus limiting purification efficiency. While centralized purification methods have been attempted in some projects, limitations in equipment placement and maintenance conditions mean that large space requirements and inconvenient installation and maintenance persist, making it difficult to meet the actual needs of shield tunnels for energy efficiency, low resistance, and minimal space requirements. Summary of the Invention

[0004] In view of the above-mentioned defects in the existing technology, the present invention provides a shield tunnel exhaust gas purification system and method. By arranging the purification device under the traveling plate and combining the piston air volume to dynamically control the operation of the bypass circuit and the fan circuit, the system achieves efficient treatment and energy-saving purification operation of the sinking particulate pollution.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: A shield tunnel exhaust gas purification system includes a purification device, an air inlet louver, an air outlet louver, an inlet pipe, an outlet pipe, and a cross duct. The purification device is arranged in a box culvert under the carriageway of the shield tunnel. The air inlet louver and the air outlet louver are installed on the side wall of the carriageway. One end of the inlet pipe is connected to the air inlet louver, and the other end is connected to the input end of the purification device through the cross duct. One end of the outlet pipe is connected to the output end of the purification device through the cross duct, and the other end is connected to the outlet louver. The purification device includes a purification module, a fan circuit, and a bypass circuit. The fan circuit and the bypass circuit are arranged in parallel and are controlled to open or close by separately installed electric air valves. A purification fan is installed in the fan circuit, which is used to forcibly extract exhaust gas when the air volume is low.

[0006] Preferably, the purification module is located near the output end of the purification device and includes a high-efficiency filtration module and an adsorption module. The high-efficiency filtration module is used to remove particulate matter, and the adsorption module is used to remove harmful gases.

[0007] Preferably, the inlet pipe and outlet pipe are arranged close to the tunnel wall, utilizing the space between the tunnel sidewall and the clearance.

[0008] Preferably, the purification device, inlet pipe, outlet pipe, and cross duct are fixed inside the box culvert under the traveling plate by steel brackets.

[0009] Preferably, it also includes a wind speed sensor installed in the tunnel and a control device electrically connected thereto. The control device is electrically connected to the electric air valve and the purification fan respectively, and is used to automatically adjust the opening state of the fan circuit and the bypass circuit according to the piston air volume information collected by the wind speed sensor.

[0010] Preferably, it further includes an air inlet induction device and an air outlet induction device. The air inlet induction device is disposed between the air inlet louvers and the inlet pipe. The air inlet louvers are arranged at an angle of about 15° relative to the direction of travel to form a duct structure to induce external exhaust gas into the inlet pipe. The air outlet induction device is disposed between the air outlet pipe and the air outlet louvers. The air outlet louvers are arranged at an angle of about 165° relative to the direction of travel to avoid short-circuiting backflow between the purified gas and the inlet airflow.

[0011] On the other hand, the present invention also discloses a method for purifying exhaust gas in shield tunnels, applied to the aforementioned shield tunnel exhaust gas purification system, comprising the following steps: S1, start the purification device, and guide the exhaust gas in the tunnel into the inlet pipe through the air inlet louvers; S2, so that the waste gas entering the cross duct flows through the purification device, and selects either the fan circuit or the bypass circuit according to the working conditions; S3, after the purification device completes the particulate matter filtration and harmful gas adsorption, the exhaust gas is transported through the air outlet pipe to the air outlet louvers and discharged into the tunnel.

[0012] Preferably, step S2 further includes step S21, which involves collecting piston airflow information output by a wind speed sensor installed in the tunnel and transmitting the piston airflow information to a control device.

[0013] Preferably, after step S21, step S22 is further included, in which when the control device determines that the piston air volume is greater than the first preset threshold, the electric air valve is controlled to close the fan circuit and open the bypass circuit, so that the exhaust gas can flow naturally without the drive of the fan.

[0014] Preferably, after step S21, step S23 is further included, in which when the control device determines that the piston air volume is less than the second preset threshold, the electric air valve is controlled to close the bypass circuit and the fan circuit is turned on, so that the purification fan provides suction power to achieve forced purification.

[0015] This invention primarily targets traffic tunnels, where particulate matter from vehicle exhaust and tire and braking emissions are concentrated in the lower part of the tunnel. Consequently, the concentration of particulate matter is high and visibility is low in the lower section. Furthermore, drivers and passengers require high visibility in the lower space for safe driving, necessitating improvements in visibility levels. Compared to existing technologies, the advantages of this invention are: (1) The present invention arranges the purification device in the lower corridor of the tunnel carriageway. By arranging it in accordance with the natural settling path of exhaust gas particles, it achieves source purification of pollutants in the lower area. Compared with the top or side exhaust method, the purification path is shorter and the efficiency is higher. It can also achieve synergistic treatment of particulate matter filtration and harmful gas adsorption at the same time, which significantly improves the air quality inside the tunnel.

[0016] (2) The present invention uses the lower corridor purification device as the core unit, and with the wind speed sensor installed in the tunnel, it realizes real-time collection and intelligent analysis of piston air volume information. According to the working conditions, it automatically switches between "bypass natural circulation" and "forced fan purification" modes. The system can dynamically judge the purification needs and autonomously plan the operating status. Under high piston air volume conditions, purification can be completed without the operation of the fan, effectively reducing operating energy consumption, while improving the dynamic adaptability and operating stability of the system.

[0017] (3) There is a certain amount of extra space in the lower part of the shield tunnel. This invention does not require additional tunnel excavation, does not increase costs, effectively utilizes the tunnel cross-sectional space, and the purification equipment is arranged in the lower part, which is also convenient for inspection and maintenance, forming a compact structure with strong civil engineering adaptability; at the same time, it can reduce equipment occupation and modification costs, and improve the overall construction feasibility and later maintenance convenience. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the air intake of the shield tunnel exhaust gas purification system according to an embodiment of the present invention.

[0019] Figure 2 This is a cross-sectional view of the exhaust gas purification system for a shield tunnel according to an embodiment of the present invention.

[0020] Figure 3 This is a plan view of the undercarriage of the shield tunnel exhaust gas purification system according to an embodiment of the present invention.

[0021] Figure 4 This is an elevation layout diagram of the exhaust gas purification system for a shield tunnel according to an embodiment of the present invention.

[0022] Figure 5 This is a plan view of the roadway layout of the shield tunnel exhaust gas purification system according to an embodiment of the present invention.

[0023] Figure 6 This is a schematic diagram of the process for purifying exhaust gas in a shield tunnel according to an embodiment of the present invention.

[0024] Figure 7 This is a flowchart illustrating step S2 of the shield tunnel exhaust gas purification method according to an embodiment of the present invention.

[0025] Explanation of reference numerals in the attached drawings: 1-Purification device; 2-Inlet louver; 3-Outlet louver; 4-Inlet pipe; 5-Outlet pipe; 6-Cross duct; 7-Purification module; 8-Fan circuit; 9-Bypass circuit; 10-Electric damper; 11-Purification fan; 12-Wind speed sensor; 13-Control device; 14-Inlet air induction device; 15-Outlet air induction device. Detailed Implementation

[0026] 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.

[0027] 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.

[0028] like Figure 1-5As shown, this embodiment discloses a shield tunnel exhaust gas purification system, including a purification device 1, an air inlet louver 2, an air outlet louver 3, an inlet pipe 4, an outlet pipe 5, and a cross duct 6. The purification device 1 is arranged in the box culvert under the carriageway of the shield tunnel, that is, the core purification structure is set near the pollution settling area, so that particulate matter can be treated nearby after being deposited by gravity, thereby improving the purification efficiency of the lower space. The air inlet louver 2 and the air outlet louver 3 are set on the side wall of the carriageway. One end of the inlet pipe 4 is connected to the air inlet louver 2, and the other end is connected to the input end of the purification device 1 through the cross duct 6. Exhaust gas is introduced into the purification device 1 through the inlet pipe 4 and the cross duct 6. One end of the outlet pipe 5 is connected to the output end of the purification device 1 through the cross duct 6, and the other end is connected to the air outlet louver 3, so that the purified airflow is discharged back into the tunnel passage section through the other section of the cross duct 6 and the outlet pipe 5. The purification device 1 includes a purification module 7, a fan circuit 8, and a bypass circuit 9. The purification module 7 is used to complete the particle filtration and harmful gas adsorption treatment of the exhaust gas. The fan circuit 8 and the bypass circuit 9 are connected in parallel and the opening or closing of the circuit is controlled by the electric air valves 10 respectively, so as to flexibly switch the airflow path according to different air volume conditions. A purification fan 11 is provided in the fan circuit 8. The purification fan 11 is used to force the exhaust gas to be drawn in when the air volume is low, so as to ensure that the effective purification capacity can still be maintained when the piston air is insufficient.

[0029] Furthermore, the purification module 7 is located near the output end of the purification device 1 and includes a high-efficiency filtration module and an adsorption module. The high-efficiency filtration module is used to remove particulate matter, and the adsorption module is used to remove harmful gases. The high-efficiency filtration module is located at the front end so that large particulate pollutants are intercepted first, and the adsorption module further processes trace volatile pollutants, forming a two-stage synergistic purification path to improve the overall purification effect.

[0030] like Figure 1-2 As shown, the inlet pipe 4 and outlet pipe 5 are arranged close to the tunnel wall, utilizing the space between the tunnel sidewall and the clearance. This wall-mounted arrangement avoids encroaching on the vehicle's travel space, reduces pipe bend losses, facilitates smoother airflow, and minimizes construction modifications. Furthermore, the purification device 1, inlet pipe 4, outlet pipe 5, and cross duct 6 are fixed to the box culvert under the traveling plate using steel brackets. The overall support provided by the structural steel allows for installation without damaging the original tunnel structure, and creates a maintainable, quick-assembly and disassembly interface for easy subsequent maintenance and module replacement.

[0031] This embodiment also includes a wind speed sensor 12 installed in the tunnel and a control device 13 electrically connected to it. The wind speed sensor 12 is used to monitor the piston air volume generated during train operation in real time and uses this data as a criterion for switching purification modes. The control device 13 is electrically connected to the electric air valve 10 and the purification fan 11 respectively. By calculating and analyzing the feedback data from the wind speed sensor 12, the opening state of the fan circuit 8 and the bypass circuit 9 can be automatically adjusted according to different air volume states to realize the intelligent switching from "natural circulation purification" to "forced fan purification", thereby avoiding energy waste caused by long-term fan operation, while ensuring stable purification processing capacity under low air volume conditions.

[0032] like Figure 5 As shown, this embodiment also includes an air inlet induction device 14 and an air outlet induction device 15. The air inlet induction device 14 is disposed between the air inlet louver 2 and the inlet pipe 4. The air inlet louver 2 is inclined at about 15° relative to the direction of travel to form a duct structure to induce external exhaust gas into the inlet pipe 4. This arrangement essentially utilizes the guiding angle of the louver itself in conjunction with the airflow capture window formed by the induction structure, so that the deposited pollutant airflow near the bottom of the tunnel is naturally drawn into the purification path without additional power, thereby improving the front-end diversion efficiency. The air outlet induction device 15 is disposed between the air outlet pipe 5 and the air outlet louver 3. The air outlet louver 3 is inclined at about 165° relative to the direction of travel to avoid short-circuiting backflow between the purified gas and the inlet airflow. This forward discharge structure allows the clean gas to rejoin the main airflow along the direction of travel, avoiding being re-inhaled into the loop and causing a decrease in purification efficiency, thereby forming a stable unidirectional flow field.

[0033] Please see Figure 6-7 Another embodiment of the present invention discloses a method for purifying exhaust gas in a shield tunnel, applied to the aforementioned shield tunnel exhaust gas purification system, comprising the following steps: S1, start the purification device 1, and guide the exhaust gas in the tunnel into the inlet pipe 4 through the air inlet louvers 2; in this process, the piston wind generated by the train operation drives the polluted gas in the lower area to be intercepted first and enter the purification path, reducing the dependence on the purification link in the upper space. S2, the exhaust gas entering the cross duct 6 flows through the purification device 1, and selects either the fan circuit 8 or the bypass circuit 9 according to the operating conditions; the operating conditions here are determined based on the real-time air volume data fed back by the wind speed sensor 12.

[0034] S3, after the purification device 1 completes the particulate matter filtration and harmful gas adsorption, the exhaust gas is transported through the air outlet pipe 5 to the air outlet louver 3 and discharged into the tunnel; the purified clean airflow merges into the main airflow of the channel in the forward direction to avoid backflow and re-inhalation, forming a stable and closed-loop purification channel.

[0035] Furthermore, step S2 also includes step S21, which involves collecting piston airflow information output by the wind speed sensor 12 installed in the tunnel and transmitting the piston airflow information to the control device 13. This step, by monitoring the piston airflow in real time, enables the system to accurately identify the current airflow intensity in the tunnel, providing a dynamic basis for subsequent purification mode selection. Specifically, after step S21, step S22 is also included, where, when the control device 13 determines that the piston airflow is greater than a first preset threshold, it controls the electric air valve 10 to close the fan circuit 8 and open the bypass circuit 9, allowing the exhaust gas to pass through without the fan. Driven by natural airflow, the device utilizes the large air volume generated by the train's operation to achieve passive purification, thereby reducing energy consumption and maintaining a stable purification effect under high piston airflow conditions. Following step S21, step S23 is also included: when the control device 13 determines that the piston airflow is less than the second preset threshold, it controls the electric air valve 10 to close the bypass circuit 9 and open the fan circuit 8, with the purification fan 11 providing suction power to achieve forced purification. This pressurized operation mode ensures that the purification capacity is not affected in low airflow environments, thus ensuring that the system has a continuous purification effect under different airflow conditions. The first preset threshold is greater than the second preset threshold.

[0036] In this embodiment, the purification device 1 has multiple operating modes. When executing the "high piston air volume" mode, the electric air valve 10 opens the bypass circuit 9 and shuts down the purification fan 11. The exhaust gas in the tunnel flows directly through the air inlet louver 2, the air inlet induction device 14, the inlet pipe 4, the electric air valve 10 on the bypass circuit 9 side, the bypass circuit 9, the purification module 7, the air outlet pipe 5, the air outlet induction device 15, and the air outlet louver 3. This operating path relies on the piston air pressure difference generated by the train operation to achieve natural transport, and the purification channel can be completed without the additional suction force of the fan, thereby reducing energy consumption under high air volume conditions. To reduce energy consumption and improve the energy-saving effect of the device; when executing the "low piston air volume" mode, the electric air valve 10 closes the bypass circuit 9 and starts the purification fan 11. The exhaust gas in the tunnel is transported and discharged through the air inlet louver 2, air inlet induction device 14, inlet pipe 4, electric air valve 10 on the fan circuit 8 side, purification fan 11, purification module 7, air outlet pipe 5, air outlet induction device 15 and air outlet louver 3. In this path, the purification fan 11 provides additional pressure difference to ensure that there is still sufficient flow rate and purification flux under low air volume conditions, ensuring that pollutants are fully removed and that the purification performance is not affected by the fluctuation of operating conditions.

[0037] In summary, this invention discloses a shield tunnel exhaust gas purification system and method. A purification device 1 is installed under the traveling plate, forming a continuous purification channel by combining an air inlet louver 2, an inlet pipe 4, a purification module 7, an outlet pipe 5, and an outlet louver 3. A fan circuit 8 and a bypass circuit 9 are connected in parallel, and intelligent purification mode control is achieved through an electric air valve 10 and a purification fan 11. This invention adopts a lower corridor layout, bringing the purification device 1 closer to the particulate pollution settling area, shortening the transport path at the source and improving particulate matter capture efficiency. Simultaneously, by introducing a bypass circuit 9 in conjunction with a wind speed sensor 12 and a control device 13, dynamic identification of the piston airflow is achieved, flexibly switching the purification mode according to the real-time airflow in the tunnel, ensuring purification effectiveness while optimizing energy consumption. This design fully adapts to the airflow characteristics and spatial layout conditions inside shield tunnels, improving purification efficiency while reducing operating costs. It has significant engineering application value for ventilation and purification technology in underground rail transit and long-section shield tunnels, and can provide a replicable application paradigm for the green and intelligent ventilation and purification of subsequent deep-buried, long-section, and high-density traffic tunnels.

[0038] 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 shield tunnel exhaust gas purification system characterized by comprising: The invention relates to a tunnel exhaust gas purification device, comprising a purification device (1), an air inlet louver (2), an air outlet louver (3), an air inlet pipe (4), an air outlet pipe (5) and a cross air pipe (6), wherein the purification device (1) is arranged in a box culvert under a shield tunnel vehicle lane, the air inlet louver (2) and the air outlet louver (3) are arranged on the lane side wall, one end of the air inlet pipe (4) is connected to the air inlet louver (2), the other end is connected to the input end of the purification device (1) through the cross air pipe (6), one end of the air outlet pipe (5) is connected to the output end of the purification device (1) through the cross air pipe (6), the other end is connected to the air outlet louver (3), the purification device (1) comprises a purification module (7), a fan circuit (8) and a bypass circuit (9), the fan circuit (8) and the bypass circuit (9) are arranged in parallel, and the opening or closing of the circuits is controlled by the electrically operated air valves (10) arranged respectively, the purification fan (11) is arranged in the fan circuit (8), and the purification fan (11) is used for forcibly sucking exhaust gas at low air volume.

2. The shield tunnel exhaust gas purification system according to claim 1, characterized by, The purification module (7) is close to the output end of the purification device (1) and comprises a high-efficiency filtration module and an adsorption module, the high-efficiency filtration module is used for removing particulate matters, and the adsorption module is used for removing harmful gases.

3. The shield tunnel exhaust gas purification system according to claim 2, characterized by, The air inlet pipe (4) and the air outlet pipe (5) are arranged close to the tunnel wall and utilize the space between the tunnel side wall and the limit.

4. The shield tunnel exhaust gas purification system according to claim 3, characterized by, The purification device (1), the air inlet pipe (4), the air outlet pipe (5) and the cross air pipe (6) are fixed in the box culvert under the driving plate by a section steel support.

5. The shield tunnel exhaust gas purification system according to claim 1, wherein Further comprising a wind speed sensor (12) arranged in the tunnel and a control device (13) electrically connected with the wind speed sensor (12), the control device (13) is electrically connected with the electrically operated air valves (10) and the purification fan (11) respectively, and is used for automatically regulating the opening state of the fan circuit (8) and the bypass circuit (9) according to the piston air volume information collected by the wind speed sensor (12).

6. The shield tunnel exhaust gas purification system according to claim 5, characterized by, Further comprising an air inlet inducing device (14) and an air outlet inducing device (15), the air inlet inducing device (14) is arranged between the air inlet louver (2) and the air inlet pipe (4), the air inlet louver (2) is arranged to be inclined at about 15° with respect to the driving direction to form a wind scoop structure to induce the external exhaust gas to enter the air inlet pipe (4), the air outlet inducing device (15) is arranged between the air outlet pipe (5) and the air outlet louver (3), and the air outlet louver (3) is arranged to be inclined at about 165° with respect to the driving direction to avoid the short circuit backflow of the purified gas and the inlet gas flow.

7. A method for purifying exhaust gas of a shield tunnel, applied to the shield tunnel exhaust gas purification system according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: S1, starting the purification device (1), guiding the tunnel exhaust gas into the air inlet pipe (4) through the air inlet louver (2); S2, making the exhaust gas flowing through the purification device (1) through the cross air pipe (6), and selecting any one of the fan circuit (8) or the bypass circuit (9) according to the working condition; S3, after the purification device (1) completes the filtration of particulate matters and the adsorption of harmful gases, the exhaust gas is transported to the air outlet louver (3) through the air outlet pipe (5) and is discharged to the inside of the tunnel.

8. The method according to claim 7, wherein, The step S2 further comprises a step S21 of collecting piston wind volume information output by a wind speed sensor (12) arranged in the tunnel and transmitting the piston wind volume information to the control device (13).

9. The method according to claim 8, wherein, The step S21 further comprises a step S22 of, when the control device (13) determines that the piston wind volume is greater than a first preset threshold, controlling the electric wind valve (10) to close the fan circuit (8) and open the bypass circuit (9), so that the exhaust gas is naturally circulated without driving of the fan.

10. The method of claim 8, wherein the shield tunnel exhaust gas is purified by, The step S21 further comprises a step S23 of, when the control device (13) determines that the piston wind volume is less than a second preset threshold, controlling the electric wind valve (10) to close the bypass circuit (9) and open the fan circuit (8), so that the suction power is provided by the purification fan (11) to realize forced purification.

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