A ventilation system for a double mode conversion of a tunneling shield

Abstract

The utility model discloses a kind of ventilation systems for double mode transformation of shield machine in hole, belong to hole ventilation technical field.A kind of ventilation systems for double mode transformation of shield machine in hole, including two air ducts being set in hole, the air duct is formed by a plurality of fan through air pipe series connection, one air duct is air outlet, another air duct is air inlet, the air inlet of the air outlet and the air outlet of air inlet are located in hole, the air outlet of the air outlet and the air inlet of air inlet are located outside hole;The utility model, by a plurality of fan series connection air supply, can form high air pressure, large air volume air supply system, effectively overcome the problem of wind pressure loss in long distance air supply process, thereby solve the problem that the ventilation effect of conventional single fan ventilation mode in long tunnel in prior art is not good.

Description

Technical Field

[0001] This utility model relates to the field of tunnel ventilation technology, and in particular to a ventilation system for dual-mode retrofitting of tunnel boring machines. Background Technology

[0002] In existing technologies, ventilation in shield tunnel operations faces numerous challenges, primarily stemming from factors such as the enclosed and confined construction environment and the rapid accumulation of harmful gases. During tunnel excavation, the operation of mechanical equipment and welding generate large amounts of dust, harmful gases, and high-temperature exhaust gases. Insufficient ventilation not only endangers worker health but may also pose a risk of explosion or fire. Furthermore, long-distance tunnels experience high ventilation resistance, and airflow is easily affected by changes in cross-section, support structures, and equipment layout, leading to uneven airflow distribution. Traditional fan ventilation has significant limitations in long-distance shield tunnel construction. Due to the excessive ventilation distance, severe air pressure loss results in a substantial reduction in the amount of fresh air delivered into the tunnel, consequently decreasing the effective exhaust volume. This insufficient airflow directly leads to the inability to promptly remove dust, harmful gases, and high-temperature exhaust gases from the tunnel, causing a continuous deterioration of the working environment. Especially when the tunnel is excessively long, the ventilation efficiency of ordinary axial flow fans decreases significantly, and the terminal airflow often fails to meet the minimum ventilation requirements. Meanwhile, factors such as air leakage at duct joints will further aggravate air volume loss, making the actual efficiency of the ventilation system far lower than the design value. In order to address the above problems, this application proposes a ventilation system for dual-mode retrofitting of tunnel boring machines. Utility Model Content

[0003] The purpose of this invention is to solve the problem that the traditional single-fan ventilation method in the prior art has poor ventilation effect in long tunnels, and to propose a ventilation system for the dual-mode transformation of tunnel boring machines in tunnels.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A ventilation system for dual-mode retrofitting of tunnel boring machines includes two air ducts installed inside the tunnel. Each air duct is composed of several fans connected in series via ducts. One air duct is an air outlet duct, and the other air duct is an air inlet duct. The air inlets of the air outlet duct and the air outlet of the air inlet duct are both located inside the tunnel, while the air outlets of the air outlet duct and the air inlets of the air inlet duct are both located outside the tunnel.

[0005] Preferably, two adjacent fans are connected by a duct, and the fans in the same duct blow air in the same direction. The fans are located at the two ends of the duct.

[0006] Preferably, the air inlet of the air outlet is provided with a protective component, and the air outlet of the air outlet is provided with an exhaust gas filter component.

[0007] Preferably, both the air inlet and the air outlet of the air inlet duct are equipped with air filter components.

[0008] Preferably, the duct and the fan are fixedly connected by a second flange and a clamp.

[0009] Preferably, the protective component includes a first flange and a filter screen, the filter screen being fixedly mounted on the first flange, and the first flange being fixedly mounted at the air inlet of the inner end fan of the air outlet duct.

[0010] Preferably, the exhaust gas filtration assembly includes a first filter frame, a second filter frame, and a first filter element. The second filter frame is fixedly installed at the air outlet of the fan at the outer end of the air outlet duct. The first filter frame and the second filter frame are detachably connected. The first filter element is disposed between the first filter frame and the second filter frame.

[0011] Preferably, the air filtration assembly includes a third filter frame, a fourth filter frame, and a second filter element. The fourth filter frame is fixedly mounted on the end fan of the air inlet duct. The third filter frame and the fourth filter frame are detachably connected. The second filter element is disposed between the third filter frame and the fourth filter frame.

[0012] Compared with the prior art, this utility model provides a ventilation system for dual-mode retrofitting of tunnel boring machines, which has the following beneficial effects.

[0013] 1. This utility model uses several fans connected in series to form a high-pressure, high-volume air supply system, which effectively overcomes the problem of air pressure loss during long-distance air supply, thereby solving the problem of poor ventilation effect of traditional single-fan ventilation methods in long tunnels in the prior art.

[0014] 2. This utility model, by setting up an air inlet duct and an air outlet duct, can form a directional airflow. The air inlet duct is used to deliver fresh air into the tunnel, and the air outlet duct is used to exhaust the gas in the tunnel. This can improve the efficiency of exhausting harmful gases and ensure the construction environment.

[0015] 3. This utility model, through the exhaust gas filtration component, can filter and purify the exhaust gas, reducing pollution to the outside world. Through the air filtration component, air filtration can be achieved, preventing unclean fresh air from being introduced into the cave.

[0016] Other advantages, objectives and features of this invention will be set forth in part in the description which follows; and in part will be apparent to those skilled in the art upon examination of the following description; or may be taught from practice of this invention. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0018] Figure 2This is a cross-sectional structural diagram of the air outlet duct in this utility model.

[0019] Figure 3 This utility model Figure 2 Enlarged structural diagram at point A in the middle.

[0020] Figure 4 This is a cross-sectional structural diagram of the exhaust gas filtration component in this utility model.

[0021] Figure 5 This is a cross-sectional structural diagram of the protective component in this utility model.

[0022] Figure 6 This is a cross-sectional structural diagram of the air inlet duct in this utility model.

[0023] Figure 7 This utility model Figure 6 Enlarged structural diagram at point B.

[0024] Figure 8 This is a schematic diagram showing the disassembled structure of the air filter component in this utility model.

[0025] Figure 9 This is a schematic diagram of the structure of the fan in this utility model.

[0026] Figure 10 This is a schematic diagram of the structure of the second flange and clamp in this utility model.

[0027] In the picture: 1. Air outlet duct; 2. Air inlet duct; 3. First flange; 4. Fan; 5. Second flange; 6. Air duct; 7. Clamp; 8. First filter frame; 9. Second filter frame; 10. First protective net; 11. Protrusion; 12. Second protective net; 13. Third filter frame; 14. Fourth filter frame; 15. First filter element; 16. Filter screen; 17. Second filter element. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings. The drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0029] Please refer to Figures 1-10 A ventilation system for dual-mode retrofitting of tunnel boring machines includes two air ducts installed inside the tunnel. Each air duct is composed of several fans 4 connected in series via air pipes 6. One air duct is an outlet air duct 1, and the other air duct is an inlet air duct 2. The air inlet of the outlet air duct 1 and the air outlet of the inlet air duct 2 are both located inside the tunnel, while the air outlet of the outlet air duct 1 and the air inlet of the inlet air duct 2 are both located outside the tunnel.

[0030] In a specific embodiment of this utility model, the traditional single-fan air supply mode often suffers from insufficient effective air volume reaching the work surface due to factors such as long air supply distance, high duct resistance, high air leakage rate, and limited space in the tunnel. This results in low ventilation efficiency, inability to dilute and expel harmful gases in a timely manner, and the working environment remaining in an excessive state for a long time. To overcome this technical bottleneck, we have innovatively adopted a ventilation scheme that combines multi-fan series air supply with counter-ventilation. On the air supply side (air inlet duct 2), several small fans are arranged in series through ducts to form a relay air supply system, which significantly improves the air supply pressure and air volume, ensuring that fresh air can be efficiently delivered to the work position. At the same time, on the exhaust side (air outlet duct 1), fan groups with the same power as the air supply side are symmetrically set to form a forced exhaust system, which enables the polluted gas to be quickly and directionally discharged.

[0031] Two adjacent fans 4 are connected by air duct 6. The fans 4 in the same air duct blow air in the same direction. The fans 4 are located at the two ends of the air duct.

[0032] Specifically, two adjacent fans 4 are connected end-to-end through a duct 6. That is, the outlet of the previous fan 4 is connected to one end of the duct 6, and the other end of the duct 6 is connected to the inlet of the next fan 4. This arrangement is repeated to form a series connection of fans 4, which forms an air duct. The outlet duct 1 and the inlet duct 2 are arranged in the same way, except that the air flow direction is different. The air in the inlet duct 2 enters from the outside to the inside, and the air in the outlet duct 1 is discharged from the inside to the outside. The number of fans 4 is determined according to the tunnel length, such as one fan 4 every 10 meters. In this scheme, since a series fan supply mode is adopted, small fans can be selected for the fans 4. High-strength air bags can be selected for the duct 6. The fans 4 can be suspended in the tunnel or supported by a support frame. The specific arrangement should be reasonably determined according to the actual situation in the tunnel.

[0033] The air inlet of the air outlet 1 is equipped with a protective component, and the air outlet of the air outlet 1 is equipped with an exhaust gas filter component. The protective component can prevent large particles of debris from entering the air outlet 1 from the work area. The exhaust gas filter component can filter the discharged polluted gas to prevent the discharged gas from polluting the external gas too much.

[0034] Both the air inlet and outlet of the air inlet duct 2 are equipped with air filter components; the air filter components ensure that the air supplied into the tunnel is clean, thereby improving the air quality in the work area.

[0035] The duct 6 and the fan 4 are fixedly connected by the second flange 5 and the clamp 7. Specifically, the second flange 5 is fixedly connected to the end of the corresponding fan 4 by bolts and nuts. The duct 6 is fitted onto the end of the second flange 5, and then the clamp 7 is used to cover the circumference of both the duct 6 and the second flange 5 for fixation.

[0036] The protective assembly includes a first flange 3 and a filter screen 16. The filter screen 16 is fixedly mounted on the first flange 3, and the first flange 3 is fixedly mounted at the air inlet of the inner end fan 4 of the air outlet duct 1.

[0037] Specifically, the first flange 3 is fixedly connected to the end of the air inlet of the inner fan 4 of the air outlet duct 1, and the filter screen 16 is fixedly installed at the end of the first flange 3. The filter screen 16 can achieve the filtering effect and is mainly used to filter large debris to prevent it from entering the air outlet duct 1.

[0038] The exhaust gas filtration assembly includes a first filter frame 8, a second filter frame 9, and a first filter element 15. The second filter frame 9 is fixedly installed at the air outlet of the outer end fan 4 of the air outlet duct 1, that is, at the end of the air outlet of the outer end fan 4. The first filter frame 8 and the second filter frame 9 are detachably connected. The first filter element 15 is disposed between the first filter frame 8 and the second filter frame 9.

[0039] The first filter frame 8 and the second filter frame 9 can be connected by threads. The first filter element 15 is sandwiched between the first filter frame 8 and the second filter frame 9. The first filter element 15 can be used to filter polluted gas, prevent a large amount of harmful gas from being directly discharged into the outside air, and reduce the impact on the outside air. A first protective net 10 is fixedly installed at the outer end of the first filter frame 8 to protect the first filter element 15.

[0040] By placing the exhaust gas filter assembly at the outlet of the air outlet duct 1 instead of the inlet, the filtered pollutants can be prevented from remaining inside the duct, thereby further improving the environmental quality of the work area.

[0041] The air filtration assembly includes a third filter frame 13, a fourth filter frame 14, and a second filter element 17. The fourth filter frame 14 is fixedly mounted on the end fan 4 of the air inlet duct 2. The third filter frame 13 and the fourth filter frame 14 are detachably connected. The second filter element 17 is disposed between the third filter frame 13 and the fourth filter frame 14.

[0042] Specifically, air filter components are installed on both the outer and inner fan 4 of the air inlet duct 2. The fourth filter frame 14 corresponding to the outer fan 4 is fixedly installed at the air inlet end of the outer fan 4, and the fourth filter frame 14 corresponding to the inner fan 4 is fixedly installed at the air outlet end of the inner fan 4. The third filter frame 13 and the fourth filter frame 14 are connected by threads. The second filter element 17 is sandwiched between the third filter frame 13 and the fourth filter frame 14. The second filter element 17 can filter and purify the air, making the gas sent into the duct relatively clean. A second protective net 12 is fixedly installed at the outer end of the third filter frame 13 to protect the second filter element 17. The first filter element 15 and the second filter element 17 can both be existing conventional air filter elements. In order to facilitate the connection and disassembly between the third filter frame 13 and the fourth filter frame 14, a protrusion 11 is provided on the third filter frame 13 to facilitate the twisting of the third filter frame 13.

[0043] During operation, air inlet duct 2 and air outlet duct 1 start simultaneously. The fan 4 of air inlet duct 2 delivers fresh air into the tunnel. During the delivery of fresh air, the air filter assembly filters the fresh air to ensure that the air delivered into the tunnel is clean, thereby improving the air quality in the work area. The fan 4 of air outlet duct 1 exhausts air outward, forcibly expelling the polluted gas from the tunnel. During the exhaust process, the protective assembly filters large particles of debris, while the exhaust gas filter assembly filters the exhaust gas to prevent excessive pollution of the outside air.

[0044] When the tunnel boring machine (TBM) is being modified inside the tunnel, it involves a large number of high-intensity hot work operations such as welding and cutting, which continuously generate high concentrations of harmful substances such as carbon monoxide, nitrogen oxides, and metal fumes, making the working environment extremely harsh. We have tried traditional ventilation methods such as long-distance air supply with a single fan, welding fume purifiers, and adding high-power DC fans. However, due to the narrow and enclosed space structure inside the TBM, the air pressure drops significantly after the air supply distance exceeds 500 meters, and the air leakage rate at the duct joints is high. The actual effective air volume reaching the welding work surface is insufficient, resulting in the continuous accumulation of harmful gases. The CO concentration has been maintained at a dangerous level of 800 ppm for a long time, far exceeding the national standard limit of 24 ppm. The low ventilation efficiency not only affects the personal safety of the workers but also affects the construction progress.

[0045] For example, in the tunnel boring machine (TBM) modification section with a diameter of only 6.4 meters, the actual measured welding fume dissipation time was shortened from 120 minutes to 18 minutes, and the NOx emission concentration decreased by 76%. At the same time, it can ensure that the oxygen and harmful gas content are within the normal range during normal welding and cutting operations. This scheme is specifically designed for the complex working conditions of multi-level working platforms working simultaneously in the confined space inside the TBM shell. It can effectively improve the ventilation environment of the working area and ultimately achieve dynamic compliance of oxygen and harmful gas concentrations throughout the modification area.

[0046] A comprehensive ventilation scheme employing multiple small fans connected in series for air supply and counter-current exhaust significantly improves air circulation efficiency within the tunnel, ensuring the safety of the working environment and the continuity of construction. The core of this scheme lies in using multiple small fans connected in series to form a high-pressure, high-volume air supply system, effectively overcoming the problem of air pressure loss during long-distance air supply. Simultaneously, fans of the same specifications are arranged on the other side of the tunnel for centralized exhaust, forming a directional airflow and greatly improving the efficiency of harmful gas removal. Practical application shows that the modified ventilation system can control the concentration of harmful gases at the work surface below the safe threshold, fully complying with the requirements of the "Tunnel Construction Safety Code." Furthermore, this scheme has three significant advantages: firstly, its modular design allows for flexible adjustment of the number of fans according to the tunnel length; secondly, its energy consumption is lower than that of traditional high-power fans; and thirdly, the synergistic effect of positive and negative pressure enables rapid air replacement in the work area, significantly improving ventilation efficiency. Construction personnel reported that after the new system was put into operation, visibility in the work area significantly improved, breathing discomfort was eliminated, and the effective daily working time increased from the original 4 hours to 8 hours, ensuring the project progress. Even under continuous welding conditions, the oxygen content in the working area remained above 19.5%, and the fluctuation range of toxic gas concentration was reduced by 85%. This solution not only solved the ventilation problem in the tunnel boring machine retrofit, but also provided a replicable ventilation optimization model for industrial operations in similar confined spaces, with significant economic and social benefits.

[0047] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

[0048] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A ventilation system for dual-mode retrofitting of tunnel boring machines, characterized in that, It includes two air ducts set inside the cave. The air ducts are formed by connecting several fans (4) through air pipes (6). One air duct is an air outlet (1) and the other air inlet (2). The air inlet of the air outlet (1) and the air outlet of the air inlet (2) are both located inside the cave, while the air outlet of the air outlet (1) and the air inlet of the air inlet (2) are both located outside the cave.

2. The ventilation system for dual-mode retrofitting of tunnel boring machines according to claim 1, characterized in that, The two adjacent fans (4) are connected by air ducts (6). The fans (4) in the same air duct blow in the same direction. The fans (4) are located at the two ends of the air duct.

3. A ventilation system for dual-mode retrofitting of tunnel boring machines according to claim 2, characterized in that, The air inlet of the air outlet (1) is equipped with a protective component, and the air outlet of the air outlet (1) is equipped with a waste gas filter component.

4. A ventilation system for dual-mode retrofitting of tunnel boring machines according to claim 1, characterized in that, The air inlet and outlet of the air inlet duct (2) are both equipped with air filter components.

5. A ventilation system for dual-mode retrofitting of tunnel boring machines according to claim 1, characterized in that, The duct (6) and the fan (4) are fixedly connected by a second flange (5) and a clamp (7).

6. A ventilation system for dual-mode retrofitting of tunnel boring machines according to claim 3, characterized in that, The protective assembly includes a first flange (3) and a filter screen (16). The filter screen (16) is fixedly mounted on the first flange (3), and the first flange (3) is fixedly mounted at the air inlet of the inner end fan (4) of the air outlet duct (1).

7. A ventilation system for dual-mode retrofitting of tunnel boring machines according to claim 3, characterized in that, The exhaust gas filtration assembly includes a first filter frame (8), a second filter frame (9), and a first filter element (15). The second filter frame (9) is fixedly installed at the air outlet of the fan (4) at the outer end of the air outlet duct (1). The first filter frame (8) and the second filter frame (9) are detachably connected. The first filter element (15) is installed between the first filter frame (8) and the second filter frame (9).

8. A ventilation system for dual-mode retrofitting of tunnel boring machines according to claim 4, characterized in that, The air filtration assembly includes a third filter frame (13), a fourth filter frame (14), and a second filter element (17). The fourth filter frame (14) is fixedly mounted on the end fan (4) of the air inlet duct (2). The third filter frame (13) and the fourth filter frame (14) are detachably connected. The second filter element (17) is located between the third filter frame (13) and the fourth filter frame (14).

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