Small-section tunnel construction ventilation device and construction system

Abstract

The utility model discloses a small-section tunnel construction ventilation device and a construction system. The small-section tunnel construction ventilation device comprises a ventilation shaft and an exhaust shaft. The upper end of the ventilation shaft is connected with a compressed air duct and an air inlet fan located in the compressed air duct, and the lower end of the ventilation shaft is provided with a flow guide cover located in the tunnel. The upper end of the exhaust shaft is connected with an exhaust duct and an exhaust fan positioned in the exhaust duct, and the lower end of the exhaust shaft is communicated with the tunnel; the ventilation shaft and the exhaust shaft are both constructed to be small-diameter shafts, and the depths of the two shafts are both smaller than the distance between the shafts and the tunnel portal. The small-section tunnel construction system comprises the small-section tunnel construction ventilation device. By arranging the small-diameter vertical shaft, the construction requirement of a small-section tunnel is met, construction is convenient, and the construction difficulty and cost are reduced; the problem that in the prior art, an air pipe extrudes the construction operation space is solved, and the problem that the air pressure loss is too large due to the too long ventilation distance can also be avoided.

Description

Technical Field

[0001] This utility model relates to the field of tunnel construction technology, specifically to a ventilation device and construction system for small-section tunnel construction. Background Technology

[0002] Tunnel construction is a typical confined space operation. During construction, there are long-term exposures to blasting fumes, worker respiration, exhaust fumes from machinery, and toxic gases seeping from underground rock fissures, seriously endangering the lives and health of construction workers. Therefore, ventilation must be implemented throughout the entire tunnel construction process. Common ventilation methods during tunnel construction include tunnel ventilation, pure pressure ventilation, pure pressure-suction ventilation, a combination of pressure and suction ventilation, and exhaust ventilation. Among these, pure pressure ventilation, pure pressure ventilation, and a combination of pressure and suction ventilation all require ventilation ducts to be laid along the tunnel towards the excavation face. Tunnel ventilation requires the additional construction of ventilation tunnels outside the main tunnel construction, increasing project investment.

[0003] In highway, railway, and municipal engineering projects, tunnels are primarily for vehicle and pedestrian traffic, resulting in large cross-sections and ample space. During construction, ventilation, water, and electrical lines can be flexibly arranged along the tunnel sidewalls and arch without affecting the passage of construction equipment and personnel. The ventilation tunnels required for tunnel-type ventilation are smaller in scale compared to the main tunnel they serve, and the cost of excavating these tunnels represents a smaller proportion of the main project investment. However, in water conservancy projects, particularly in the construction of terminal branch canals and distribution channels for water diversion projects, where only water flow is required and the flow rate is relatively small, the tunnel cross-sections are smaller than those in highway, railway, and municipal engineering projects. This leads to limited working space during construction, making it impossible to install commonly available ventilation equipment and ducts inside the tunnels. Installing such equipment would restrict the movement of workers and essential equipment. Furthermore, smaller duct cross-sections result in greater air pressure loss and lower ventilation efficiency. The formula for calculating air pressure loss through duct resistance is as follows: h 沿 =α×L×U×P L ×Q 2 ×g / S 3 It can be seen that the pipe resistance loss due to wind pressure h 沿 With the cross-sectional area of ​​the air duct S The cost is directly proportional to the cube of the duct's cross-sectional area. This means that when the duct cross-sectional area is too small, the friction loss along the duct increases significantly, leading to low ventilation efficiency and even preventing airflow from forming at the duct outlet. Furthermore, tunnel-type ventilation suffers from excessively high costs because the construction cost of the ventilation tunnel is significantly higher than the main construction cost of the small-section tunnel.

[0004] A search revealed that Chinese patent application publication number CN112814721A discloses a smoke extraction method for shallow-buried tunnel construction, comprising a hybrid ventilation system consisting of forced ventilation and vertical shaft smoke extraction ducts. However, this patent has the following limitations when used in small-section tunnels: the ventilation system requires forced ventilation ducts to be arranged along the tunnel arch to the tunnel face, occupying the tunnel cross-section and affecting the passage of machinery and personnel in small-section tunnels. Furthermore, the ventilation effect of forced ventilation gradually decreases as the tunnel excavation distance increases. In addition, the smoke extraction system is a non-powered system utilizing the chimney effect, resulting in excessively low smoke extraction efficiency in situations requiring the rapid removal of large amounts of smoke and dust, such as during blasting. Patent authorization publication number CN217632530U discloses a hybrid tunnel ventilation structure, including a fresh air forced ventilation system and an exhaust system. The forced ventilation duct and the exhaust duct pass through vertical shafts and horizontal passages into the tunnel interior. The tunnel is divided into an upper pilot tunnel and a lower pilot tunnel. The duct and exhaust pipe are arranged along the length of the lower guide pit and the upper guide pit, respectively. Although this structure solves the problems of long forced ventilation distance and low efficiency of non-powered smoke exhaust system, the ventilation duct still occupies construction space and is not suitable for ventilation in small cross-section tunnels. In addition, the forced ventilation intake and exhaust outlet are close to each other. If a filter is installed at the exhaust outlet, it is easy to get clogged in the high dust environment during construction, which will cause the exhaust polluted air to be re-inhaled into the tunnel, affecting the ventilation quality. Patent application publication number CN106948854A discloses a tunnel ventilation and smoke exhaust system and a tunnel ventilation and smoke exhaust method. The system includes at least one vertical shaft formed at the top of the tunnel; two or more jet fans are respectively set at the top of the tunnel on both sides of the vertical shaft. The jet fans guide the airflow into the vertical shaft. This system requires the installation of jet fans in the tunnel, which occupies construction space. In order to ensure the natural ventilation effect of the vertical shaft, the vertical shaft needs to have a large diameter.

[0005] In general, the existing technologies retrieved are mainly applicable to ventilation of large-section tunnels. For ventilation operations in small-section tunnels, the following problems exist: First, fans, ducts, and other facilities need to be installed inside the tunnel, occupying the tunnel construction cross-section and severely affecting the passage of machinery and personnel in small-section tunnels. Second, ventilation shafts utilizing the chimney effect for non-powered ventilation, or using pressure difference ventilation after adding a heat source, both require large-diameter exhaust shafts to ensure ventilation effectiveness; otherwise, it is difficult to meet the ventilation needs for blasting smoke dispersion. However, larger-diameter exhaust shafts often require lining; otherwise, there is a risk of shaft collapse, and the excavation and lining construction costs are high. Third, the ventilation effect of forced-flow fans installed at the tunnel entrance gradually decreases as the duct length increases. Utility Model Content

[0006] The technical problem to be solved by this utility model is that existing ventilation methods for small cross-section tunnels have various defects. The purpose is to provide a ventilation device and construction system for small cross-section tunnel construction to solve the above-mentioned problems.

[0007] This utility model is achieved through the following technical solution:

[0008] In the first aspect, this utility model provides a ventilation device for small-section tunnel construction, including a ventilation shaft and an exhaust shaft;

[0009] The ventilation shaft is installed in the base. The upper end of the ventilation shaft is connected to the compressed air duct and the air intake fan located in the compressed air duct. The lower end of the ventilation shaft is connected to the tunnel and is equipped with a guide hood located in the tunnel.

[0010] The exhaust shaft is installed in the foundation. The upper end of the exhaust shaft is connected to the exhaust duct and the exhaust fan located in the exhaust duct. The lower end of the exhaust shaft is connected to the tunnel.

[0011] Accordingly, both the ventilation shaft and the exhaust shaft are constructed as small-diameter shafts, and the depth of both shafts is less than their distance from the tunnel entrance;

[0012] Correspondingly, the opening directions of the compressed air duct and the exhaust air duct are opposite to each other, and the compressed air duct is lower than the exhaust air duct;

[0013] Correspondingly, the opening of the deflector faces away from the lower end of the exhaust shaft.

[0014] In one possible design, a fan room located on the base is also included, with the fan room having two opposing sides, and the compressed air duct and the exhaust air duct respectively located on one of the sides.

[0015] In one possible design, the roof of the fan room is equipped with a rain shelter; the fan room is equipped with a protective fence surrounding the shaft.

[0016] In one possible design, a dust suppression device is installed on the fan room. The dust suppression device includes a water supply pipe installed on the fan room and several atomizing nozzles located on the water supply pipe, with the atomizing nozzles facing the exhaust duct outlet.

[0017] In one possible design, protective grilles are provided on the air inlet of the compressed air duct and the air outlet of the exhaust air duct; the air inlet fan is a forced-flow axial fan, and the exhaust fan is a centrifugal fan.

[0018] In one possible design, both the intake and exhaust fans are equipped with cables that extend downward into the tunnel, and these cables are used to connect to the power cables inside the tunnel.

[0019] In one possible design, the diameters of both the ventilation shaft and the exhaust shaft are between φ150mm and φ300mm.

[0020] In one possible design, the lower end of the ventilation shaft is equipped with a rotating frame, which is connected to the flow guide and used to adjust the angle of the flow guide.

[0021] In one possible design, the rotating frame includes:

[0022] The base frame covers the lower end of the ventilation shaft. The top surface of the base frame connects to the tunnel, and the bottom surface of the base frame is used to connect to the flow guide.

[0023] A driver, mounted on the base frame, is used to drive the shroud to rotate.

[0024] There are two side baffles, which are located on both sides of the base frame respectively; correspondingly, the fairing is rotatably disposed between the two side baffles.

[0025] Secondly, this utility model provides a small-section tunnel construction system, including the aforementioned small-section tunnel construction ventilation device.

[0026] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0027] The ventilation device for small-section tunnel construction uses small-diameter vertical shafts, which on the one hand adapts to the construction needs of small-section tunnels and is easy to construct, reducing the difficulty and cost of construction and making the construction of vertical shafts more efficient and less costly; on the other hand, it solves the problem of ducts squeezing the construction work space in the prior art, and also avoids the problem of excessive wind pressure loss due to excessive ventilation distance in the prior art.

[0028] It is worth noting that the opening directions of the compressed air duct and the exhaust air duct are opposite to each other, with the compressed air duct lower than the exhaust air duct. This ensures that the incoming fresh air is separated from the outgoing polluted air, preventing polluted air from being re-injected into the tunnel. Furthermore, the toxic and harmful gases in the tunnel are mainly CO and CH4, which are less dense than air and will rise after being exhausted. Because the compressed air duct is lower than the exhaust air duct, the probability of toxic and harmful gases being re-injected into the tunnel is greatly reduced. Attached Figure Description

[0029] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0030] Figure 1 A schematic diagram of a ventilation device for small-section tunnel construction when a fan room is provided.

[0031] Figure 2 This is a cross-sectional structural diagram of a ventilation device for small-section tunnel construction when no fan room is provided.

[0032] Figure 3 This is a schematic diagram showing the connection between the ventilation shaft, the rotating frame, and the flow guide.

[0033] The attached diagram shows the markings and corresponding component names:

[0034] 1. Ventilation shaft; 2. Exhaust shaft; 3. Compressed air duct; 4. Air inlet fan; 5. Air guide hood; 6. Exhaust air duct; 7. Exhaust fan; 8. Fan room; 801. Rainproof canopy; 802. Protective fence; 9. Dust suppression device; 10. Protective grille; 11. Cable; 12. Rotating frame; 121. Base frame; 122. Driver; 123. Side baffle. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this utility model are only used to explain this utility model and are not intended to limit this utility model.

[0036] Example:

[0037] like Figures 1-3 As shown, in the first aspect, this utility model provides a ventilation device for small-section tunnel construction, including a ventilation shaft 1 and an exhaust shaft 2;

[0038] Ventilation shaft 1 is installed in the base. The upper end of ventilation shaft 1 is connected to compressed air duct 3 and air intake fan 4 located in compressed air duct 3. The lower end of ventilation shaft 1 is connected to the tunnel and is equipped with a guide hood 5 located in the tunnel.

[0039] The exhaust shaft 2 is installed in the base. The upper end of the exhaust shaft 2 is connected to the exhaust duct 6 and the exhaust fan 7 located in the exhaust duct 6. The lower end of the exhaust shaft 2 is connected to the tunnel.

[0040] Accordingly, both ventilation shaft 1 and exhaust shaft 2 are constructed as small-diameter shafts, and the depth of both shafts is less than their distance from the tunnel entrance;

[0041] Correspondingly, the opening directions of the compressed air duct 3 and the exhaust air duct 6 are opposite to each other, and the compressed air duct 3 is lower than the exhaust air duct 6;

[0042] Correspondingly, the opening of the deflector 5 faces away from the lower end of the exhaust shaft 2.

[0043] The ventilation device for small-section tunnel construction uses small-diameter vertical shafts, which on the one hand adapts to the construction needs of small-section tunnels and is easy to construct, reducing the difficulty and cost of construction and making the construction of vertical shafts more efficient and less costly; on the other hand, it solves the problem of ducts squeezing the construction work space in the prior art, and also avoids the problem of excessive wind pressure loss due to excessive ventilation distance in the prior art.

[0044] It is worth noting that the opening directions of the compressed air duct 3 and the exhaust air duct 6 are opposite to each other, with the compressed air duct 3 lower than the exhaust air duct 6. This ensures that the fresh air being forced in is separated from the stale air being exhausted, preventing stale air from being re-forced into the tunnel. Furthermore, the toxic and harmful gases in the tunnel are mainly CO and CH4, which are less dense than air and will rise after being exhausted. Because the compressed air duct 3 is lower than the exhaust air duct 6, the probability of toxic and harmful gases being re-forced into the tunnel is greatly reduced.

[0045] It is worth noting that a flow guide hood 5 is installed at the lower end of the ventilation shaft 1. The flow guide hood 5 guides the direction of gas flow, so that the gas flows away from the exhaust shaft 2, ensuring that the fresh air flows a sufficient distance and time in the tunnel, ensuring the air supply effect, and preventing the gas from being discharged by the exhaust shaft 2 as soon as it enters the tunnel.

[0046] Furthermore, an intake fan 4 and an exhaust fan 7 are respectively installed in the two shafts. Compared with the natural exhaust scheme in the prior art, the exhaust efficiency is higher and the stability is better.

[0047] During operation, staff set the relevant parameters according to the air supply requirements, and then start the intake fan 4 and exhaust fan 7. The two shafts work together to achieve continuous and stable air exchange between the inside and outside of the tunnel, diluting and expelling toxic and harmful gases and reducing dust concentration, thus ensuring the safety of staff. For long-term air supply, timely monitoring of the work situation and prompt handling of emergencies are sufficient. Therefore, the operation is simple and convenient for staff, helping to reduce workload.

[0048] In one possible implementation, the ventilation device for small-section tunnel construction also includes a fan room 8 located on the base, the fan room 8 having two opposite sides, with the compressed air duct 3 and the exhaust air duct 6 respectively located on one of the sides.

[0049] Based on the above design scheme, the fan room 8 forms a ground-level building, providing space and related support structures for the installation of the compressed air duct 3 and the exhaust air duct 6. At the same time, the fan room 8 can also be used as a rest area for staff, providing convenient conditions for maintenance and other operations.

[0050] Preferably, a rain shelter 801 is provided on the roof of the fan room 8; a protective fence 802 is provided inside the fan room 8 around the shaft. Based on this, the rain shelter 801 improves the rain and sun protection performance of the fan room 8, providing a better working and resting area for personnel. The protective fence 802 is used to separate the outside world from the shaft, preventing unauthorized personnel from entering and improving the safety of the shaft and fan operation.

[0051] It is easy to understand that the fan room 8, the rain shelter 801, and the protective fence 802 can be constructed as any suitable structure, and this utility model does not impose any restrictions on them.

[0052] In one possible implementation, a dust suppression device 9 is provided on the fan room 8. The dust suppression device 9 includes a water supply pipe installed on the fan room 8 and several atomizing nozzles located on the water supply pipe. The atomizing nozzles face the air outlet of the exhaust duct 6.

[0053] Based on the above design, the exhaust shaft 2 discharges polluted gas through the exhaust duct 6. This polluted gas includes toxic and harmful gases such as CO and CH4, as well as particulate impurities such as soil clods and pebbles. For particulate impurities, dust suppression is achieved through spraying by the dust suppression device 9, preventing pollution of the surrounding environment. Compared to existing technologies that use filter cartridges or other filtration devices, the dust suppression device 9 has a longer service life and lower cost.

[0054] Specifically, when the ventilation device for small-section tunnel construction is activated and in operation, water can be supplied to the water supply pipe, and the water can be sprayed out through the atomizing nozzle to reduce dust.

[0055] It is easy to understand that this utility model does not impose any restrictions on parameters such as the model, quantity, and layout of the atomizing nozzles. Those skilled in the art can select and combine them according to actual operational requirements to improve the adaptability and dust suppression effect of the dust suppression device 9.

[0056] In one possible implementation, protective grilles 10 are provided on both the air inlet of the compressed air duct 3 and the air outlet of the exhaust air duct 6. Based on this, the protective grilles 10 prevent debris or small animals from entering and thus avoid damaging the fan.

[0057] In one possible implementation, the intake fan 4 is a forced-flow axial fan and the exhaust fan 7 is a centrifugal fan. Based on this, and considering the small diameter of the vertical shaft, the problem of ductwork encroaching on construction work space is further solved.

[0058] Accordingly, a bushing adapted for the fan is installed inside the shaft. Based on this, the bushing can be installed below the shaft after its formation to prevent the shaft wall from collapsing and ensure the structural safety of the shaft. At the same time, the bushing also connects the shaft to the fan.

[0059] In one possible implementation, both the intake fan 4 and the exhaust fan 7 are provided with cables 11 extending downward into the tunnel, which are used to connect to power cables inside the tunnel.

[0060] Based on the above design scheme, power can be drawn from the field environment, and the control module used to control the ventilation device for the small cross-section tunnel construction can also be installed in the construction area at the tunnel entrance, which is convenient for workers to operate.

[0061] In one possible implementation, the diameters of both ventilation shaft 1 and exhaust shaft 2 are between φ150mm and φ300mm. It is easy to understand that any suitable value within this diameter range can be selected based on actual operational needs.

[0062] In one possible implementation, the lower end of the ventilation shaft 1 is equipped with a rotating frame 12, which is connected to the guide shroud 5 and used to adjust the angle of the guide shroud 5. Based on the above design, the angle of the guide shroud 5 is adjusted by rotating the frame 12 to change the flow direction and path of the gas, thereby adjusting the air supply effect. In addition to adjusting the fan parameters, control options are added to better adjust the air supply effect.

[0063] Optionally, the rotating frame 12 includes:

[0064] The base frame 121 covers the lower end of the ventilation shaft 1. The top surface of the base frame 121 is connected to the tunnel, and the bottom surface of the base frame 121 is used to connect the flow guide shroud 5.

[0065] A driver 122 is mounted on the base frame 121 and is used to drive the shroud 5 to rotate.

[0066] Two side baffles 123 are provided and are located on both sides of the base frame 121 respectively; correspondingly, the flow guide 5 is rotatably disposed between the two side baffles 123.

[0067] Based on the above design, if the angle of the flow guide 5 needs to be adjusted, the driver 122 can be activated to rotate the flow guide 5 to the appropriate angle. After the flow guide 5 rotates, the gap between the flow guide 5 and the base frame 121 is blocked by the side baffle 123, reducing air leakage and ensuring that the gas changes its flow direction according to the adjustment.

[0068] Secondly, this utility model provides a small-section tunnel construction system, including the aforementioned small-section tunnel construction ventilation device. It is readily understood that, based on the small-section tunnel construction ventilation device, the small-section tunnel construction system can also include any other suitable functional modules, resulting in richer functionality to meet different work requirements and improved practicality. Furthermore, it is readily understood that the functional modules can be any suitable existing equipment, offering a wide range of choices.

[0069] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A ventilation device for small-section tunnel construction, characterized in that, Including ventilation shafts (1) and exhaust shafts (2); The ventilation shaft (1) is installed in the base. The upper end of the ventilation shaft (1) is connected to the compressed air duct (3) and the air intake fan (4) located in the compressed air duct (3). The lower end of the ventilation shaft (1) is connected to the tunnel and is equipped with a guide hood (5) located in the tunnel. The exhaust shaft (2) is installed in the base. The upper end of the exhaust shaft (2) is connected to the exhaust duct (6) and the exhaust fan (7) located in the exhaust duct (6). The lower end of the exhaust shaft (2) is connected to the tunnel. Accordingly, both the ventilation shaft (1) and the exhaust shaft (2) are constructed as small-diameter shafts, and the depth of both shafts is less than their distance from the tunnel entrance; Correspondingly, the opening directions of the compressed air duct (3) and the exhaust air duct (6) are opposite to each other, and the compressed air duct (3) is lower than the exhaust air duct (6). Accordingly, the opening direction of the deflector (5) is opposite to the lower end of the exhaust shaft (2).

2. The small cross-section tunnel construction ventilation device according to claim 1, characterized in that, It also includes a fan room (8) located on the base, the fan room (8) having two opposite sides, with the compressed air duct (3) and the exhaust air duct (6) respectively located on one of the sides.

3. A small cross-section tunneling ventilation device according to claim 2, characterized in that, The top surface of the fan room (8) is provided with a rain shelter (801); the fan room (8) is provided with a protective fence (802) located around the shaft.

4. The apparatus according to claim 3, wherein The fan room (8) is equipped with a dust suppression device (9). The dust suppression device (9) includes a water supply pipe installed on the fan room (8) and several atomizing nozzles located on the water supply pipe. The atomizing nozzles face the exhaust duct (6) outlet.

5. The apparatus according to claim 1, wherein Protective grilles (10) are provided on the air inlet of the compressed air duct (3) and the air outlet of the exhaust air duct (6); the air inlet fan (4) is a forced-flow axial fan, and the exhaust fan (7) is a centrifugal fan.

6. A small- cross-section tunnel construction ventilation device according to claim 5, characterized in that Both the intake fan (4) and the exhaust fan (7) are equipped with cables (11) extending downward into the tunnel, which are used to connect to the power cables in the tunnel.

7. A small- cross-section tunnel construction ventilation device according to claim 6, characterized in that The diameters of the ventilation shaft (1) and the exhaust shaft (2) are both between φ150mm and φ300mm.

8. A small- cross-section tunneling ventilation device according to any of claims 1-7, characterized in that, The lower end of the ventilation shaft (1) is equipped with a rotating frame (12), which is connected to the flow guide (5) and used to adjust the angle of the flow guide (5).

9. A small- cross-section tunneling ventilation device according to claim 8, characterized in that The rotating frame (12) includes: The base frame (121) covers the lower end of the ventilation shaft (1), the top surface of the base frame (121) is connected to the tunnel, and the bottom surface of the base frame (121) is used to connect the flow guide (5). A driver (122) is mounted on the base frame (121) and is used to drive the fairing (5) to rotate; Two side baffles (123) are provided and located on both sides of the base frame (121); correspondingly, the fairing (5) is rotatably disposed between the two side baffles (123).

10. A small cross-section tunnel construction system, characterized in that, The ventilation device for small-section tunnel construction includes any one of claims 1-9.

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