A tunnel exhaust system

Abstract

The application relates to the technical field of tunnel ventilation, and discloses a tunnel exhaust system, a vertical shaft is arranged through a top wall of a tunnel, a smoke exhaust device comprises an exhaust fan, a hood, a non-powered fan, a driving mechanism and a controller, the hood is arranged at the upper end of the vertical shaft, an air inlet and an air outlet are arranged on the side wall of the hood, an exhaust port is arranged at the top of the hood, the non-powered fan is arranged in the inner cavity of the hood, the inner cavity of the hood is communicated with the inner cavity of the vertical shaft, the driving mechanism drives the hood to rotate so that the air inlet of the hood is opposite to the wind direction; the exhaust fan is arranged at the bottom of the vertical shaft, a fan driver drives the rotation of the fan blade; when an actual wind speed detected by a wind speed detection sensor is greater than a preset natural exhaust wind speed, the exhaust fan is paused, and the air inlet of the hood is opposite to the wind direction. The exhaust fan can be started and stopped according to the actual wind speed, the wind energy is fully utilized as power to drive the non-powered fan, the air circulation in the tunnel is ensured, the power consumption is reduced, and energy saving and environmental protection are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel ventilation, in particular to a tunnel exhaust system. BACKGROUND

[0002] Due to the limited space of the tunnel, it is difficult for fresh air to circulate, and various harmful gases accumulate for a long time, which is harmful to the human body. Usually, a fan is placed underground to promote the exhaust of harmful gases from the tunnel. However, due to the long-term use of the motor to drive the fan, the electric energy is greatly wasted, and since there is no sunlight in the tunnel, solar energy cannot be used for power storage. In the long run, the economic cost caused by the loss of electric energy is large, and it does not meet the requirements of energy saving and environmental protection. SUMMARY

[0003] The purpose of the present application is to provide a tunnel exhaust system which can start and stop the exhaust fan according to the actual wind speed, make full use of wind energy as power to drive the non-powered fan, ensure the air circulation inside the tunnel, reduce the consumption of electric energy, and save energy and protect the environment.

[0004] In order to achieve the above purpose, the present application provides a tunnel exhaust system, which comprises a vertical shaft and a smoke exhaust device, the vertical shaft is arranged through the top wall of the tunnel, the upper part of the vertical shaft extends to the outside ventilation area, the smoke exhaust device comprises an exhaust fan, a hood, a non-powered fan, a driving mechanism and a controller, the hood is arranged at the upper end of the vertical shaft, the side wall of the hood is provided with an air inlet and an air outlet, the top of the hood is provided with an exhaust port, the non-powered fan is arranged in the inner cavity of the hood, the inner cavity of the hood is communicated with the inner cavity of the vertical shaft, the top of the hood is provided with a wind direction detection sensor and a wind speed detection sensor, the driving mechanism is arranged on the vertical shaft, the driving mechanism is connected with the hood and drives the hood to rotate so that the air inlet of the hood is opposite to the wind direction.

[0005] The exhaust fan is arranged at the bottom of the vertical shaft, the exhaust fan comprises a fan blade, a fan driver and a breathable shell, the breathable shell is arranged at the bottom of the vertical shaft, the fan driver is mounted on the breathable shell, and the output end of the fan driver is connected with the fan blade and drives the fan blade to rotate.

[0006] The exhaust fan, the driving mechanism, the wind direction detection sensor and the wind speed detection sensor are connected with the controller respectively, when the wind speed detection sensor detects that the actual wind speed is greater than the preset natural exhaust wind speed, the exhaust fan is paused, and the air inlet of the hood is opposite to the wind direction; when the wind speed detection sensor detects that the actual wind speed is less than the preset natural exhaust wind speed, the exhaust fan is started.

[0007] As a preferred scheme of the present application, the preset natural exhaust wind speed v 自然 :

[0008]

[0009] wherein, v 自然 is a preset natural ventilation wind speed; P 进 is the pressure of the air inlet; P 出 is the pressure of the air outlet; p is the air density flowing in the external ventilation area; p 内 is the air density flowing in the tunnel; p 进 is the air density of the air inlet; p 出 is the air density of the air outlet; g is the acceleration of gravity; H is the height difference between the tunnel inlet and the tunnel outlet; v a is the actual wind speed in the tunnel; l r is the tunnel wall friction loss coefficient; L is the length of the tunnel air duct; D r is the diameter of the tunnel section; x e is the inlet local resistance coefficient.

[0010] As a preferred scheme of the present application, the driving mechanism comprises a driving gear, a transmission gear and a driving motor, the transmission gear is rotationally connected to the upper end of the shaft, the transmission gear is provided with an air vent communicating with the inner cavity of the shaft, the air cap is connected to the transmission gear, the output end of the driving motor is connected to the driving gear and drives the driving gear to rotate, and the driving gear is engaged with the transmission gear.

[0011] As a preferred scheme of the present application, the driving mechanism further comprises a shell, the shell is sleeved on the upper part of the shaft, and the driving gear, the transmission gear and the driving motor are arranged in the shell.

[0012] As a preferred scheme of the present application, the exhaust fan is detachably mounted at the bottom of the shaft.

[0013] As a preferred scheme of the present application, the upper end of the air-permeable shell is inserted into the bottom of the shaft, the lower end of the air-permeable shell is located in the tunnel, a plurality of buckle grooves are formed in the outer side wall of the lower end of the air-permeable shell, a plurality of mounting brackets are arranged on the shaft, the upper end of the mounting bracket is connected to the outer wall of the shaft through a spring, the middle part of the mounting bracket is hingedly connected to the fixed bracket on the shaft, and the lower end of the mounting bracket is buckled in the buckle groove.

[0014] As a preferred scheme of the present application, the diameter of the exhaust port is greater than the diameter of the unpowered fan.

[0015] As a preferred scheme of the present application, the center height of the unpowered fan, the center height of the air inlet and the center height of the air outlet are flush.

[0016] Preferably, the air inlet is provided with a funnel-shaped air duct.

[0017] Compared with the prior art, the tunnel exhaust system has the beneficial effects that:

[0018] The wind direction detection sensor on the air cap can sense the wind direction at any time, and the air cap is driven to rotate by the driving mechanism so that the air inlet of the air cap faces the wind direction. When there is no wind or the actual wind speed is less than the preset natural exhaust wind speed, the exhaust fan is started to exhaust the gas in the tunnel to the exhaust port, realizing ventilation of the tunnel. When the actual wind speed is greater than or equal to the preset natural exhaust wind speed, the exhaust fan is paused, and the unpowered fan is driven to rotate by air to exhaust the exhaust gas in the tunnel to the exhaust port, realizing air circulation in the tunnel. The wind energy is used as power to improve the efficiency of ventilation of the tunnel, and the exhaust fan is not needed for long-term ventilation of the tunnel, reducing power consumption and saving energy and protecting the environment. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural schematic diagram of a tunnel exhaust system provided by the embodiment of the present application;

[0020] Figure 2 is a structural schematic diagram of a tunnel exhaust system provided by the embodiment of the present application;

[0021] In the figure, the vertical shaft 1; the tunnel 2; the exhaust fan 3; the fan blade 31; the fan driver 32; the air-permeable shell 33; the buckle groove 331; the mounting bracket 34; the spring 35; the fixed bracket 36; the air cap 4; the air inlet 41; the air outlet 42; the exhaust port 43; the wind direction detection sensor 44; the unpowered fan 5; the driving mechanism 6; the driving gear 61; the transmission gear 62; the driving motor 63; the shell 64. DETAILED DESCRIPTION

[0022] The specific embodiments of the present application will be further described in detail below in conjunction with the drawings and examples. The following examples are used to illustrate the present application, but are not used to limit the scope of the present application.

[0023] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicated by the orientation or positional relationship in the present application are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance.

[0024] As Figure 1 and Figure 2 shown, the application provides a preferred embodiment of a tunnel exhaust system, which comprises a shaft 1 and a smoke exhaust device, the shaft 1 is arranged through the top wall of the tunnel 2, the upper part of the shaft 1 extends to the external ventilation area, the smoke exhaust device comprises an exhaust fan 3, a hood 4, a non-powered fan 5, a driving mechanism 6 and a controller, the hood 4 is arranged at the upper end of the shaft 1, the side wall of the hood 4 is provided with an air inlet 41 and an air outlet 42, the top of the hood 4 is provided with an exhaust port 43, the non-powered fan 5 is arranged in the inner cavity of the hood 4, the inner cavity of the hood 4 is communicated with the inner cavity of the shaft 1, the top of the hood 4 is provided with a wind direction detection sensor 44 and a wind speed detection sensor, the driving mechanism 6 is arranged on the shaft 1, the driving mechanism 6 is connected with the hood 4 and drives the hood 4 to rotate so that the air inlet 41 of the hood 4 is opposite to the wind direction;

[0025] The exhaust fan 3 is arranged at the bottom of the shaft 1, the exhaust fan 3 comprises a fan blade 31, a fan driver 32 and a breathable shell 33, the breathable shell 33 is arranged at the bottom of the shaft 1, the fan driver 32 is installed on the breathable shell 33, the output end of the fan driver 32 is connected with the fan blade 31 and drives the fan blade 31 to rotate; the fan driver 32 is specifically a driving motor 63;

[0026] The exhaust fan 3, the driving mechanism, the wind direction detection sensor 44 and the wind speed detection sensor are connected with the controller respectively, the controller can make the driving mechanism 6 work according to the wind direction fed back by the wind direction detection sensor 44, and drive the hood 4 to rotate through the driving mechanism 6 so that the air inlet 41 of the hood 4 is opposite to the wind direction, the controller can start and stop the exhaust fan 3 according to the wind speed fed back by the wind speed detection sensor, when the actual wind speed detected by the wind speed detection sensor is greater than the preset natural exhaust wind speed, the exhaust fan 3 is paused, and the air inlet 41 of the hood 4 is opposite to the wind direction; when the actual wind speed detected by the wind speed detection sensor is less than the preset natural exhaust wind speed, the exhaust fan 3 is started.

[0027] The application can sense the wind direction at any time through the wind direction detection sensor 44 on the wind cap 4, drives the wind cap 4 to rotate through the driving mechanism 6 to make the air inlet 41 of the wind cap 4 face the wind direction, when there is no wind or the actual wind speed is less than the preset natural exhaust wind speed, the exhaust fan 3 is started to exhaust the gas in the tunnel 2 to the exhaust port 43, and the ventilation of the tunnel 2 is realized; when the actual wind speed is greater than or equal to the preset natural exhaust wind speed, the exhaust fan 3 is suspended, and the air drives the unpowered fan 5 to rotate to work to exhaust the exhaust gas in the tunnel 2 to the exhaust port 43, the air circulation in the tunnel 2 is realized, the wind energy is fully utilized as the power, the ventilation efficiency of the tunnel 2 is improved, the exhaust fan 3 is not needed to be used for a long time to ventilate the tunnel 2, the power consumption is reduced, and energy saving and environmental protection are realized.

[0028] As a preferred scheme of the application, the preset natural exhaust wind speed v 自然 :

[0029]

[0030] Wherein, v 自然 is the preset natural exhaust wind speed; P 进 is the pressure of the air inlet 41; P 出 is the pressure of the air outlet 42; ρ is the air density circulating in the external ventilation area; ρ 内 is the air density circulating in the tunnel 2; ρ 进 is the air density of the air inlet 41; ρ 出 is the air density of the air outlet 42; g is the gravitational acceleration; H is the height difference between the tunnel 2 inlet and the tunnel 2 outlet, if the tunnel 2 is a horizontal tunnel 2, then H=0; v a is the actual wind speed in the tunnel 2; λ r is the friction loss coefficient of the tunnel 2 wall; L is the length of the tunnel 2 air duct; D r is the diameter of the tunnel 2 section; ξ e is the local resistance coefficient of the inlet; and λ r and ξ e are the fixed parameters of the tunnel 2. Specifically, the pressure sensors are arranged at the air inlet 41 and the air outlet 42 respectively to detect the pressure thereof; the air density sensors are arranged at the air inlet 41 and the air outlet 42 respectively to detect the air density thereof, the air density sensor is arranged outside the wind cap 4 to detect the air density circulating in the external ventilation area; the air density sensor is arranged in the inner cavity of the tunnel 2 to detect the air density circulating in the tunnel 2.

[0031] Specifically, the complete wind speed is calculated as follows: let the height difference of the tunnel 2 inlet and outlet be H, when H is small, the atmospheric density can be regarded as a constant. In an ideal case, it is assumed that the atmosphere is static, the atmospheric pressure of the tunnel 2 hole (tunnel 2 inlet and tunnel 2 outlet) is P1 (low end) and P2 (high end) respectively, and the pressure difference between the two is called static pressure difference.

[0032]

[0033] The air flow pressure difference of the tunnel 2 inlet and outlet is called super static pressure difference, and is denoted by Δ P .

[0034]

[0035] Taking the atmospheric pressure P2 of the high end hole as the reference point, Δ P represents the super static pressure difference of the atmospheric pressure P1 of the low end hole and the atmospheric pressure P2 of the high end hole. When the wind flow flows from the low end hole to the high end hole, Δ P > 0; otherwise, Δ P < 0.

[0036] For a general tunnel 2, when the comprehensive pressure difference Δ P between the two holes is known, the preset natural exhaust wind speed v 自然 can be calculated using the ventilation resistance formula, which is:

[0037]

[0038]

[0039] where v n is the wind speed in the tunnel 2 under ideal conditions.

[0040] Exemplarily, the driving mechanism 6 comprises a driving gear 61, a transmission gear 62 and a driving motor 63, the transmission gear 62 is rotatably connected to the upper end of the shaft 1, the transmission gear 62 is provided with an air vent communicating with the inner cavity of the shaft 1, the air cap 4 is connected to the transmission gear 62, the output end of the driving motor 63 is connected with the driving gear 61 and drives the driving gear 61 to rotate, the driving gear 61 is engaged with the transmission gear 62, so as to drive the driving gear 61 to rotate through the driving motor 63, drive the transmission gear 62 to rotate, and the transmission gear 62 synchronously drives the air cap 4 to rotate.

[0041] Exemplarily, the driving mechanism 6 further comprises a shell 64 sleeved on the upper portion of the shaft 1, the driving gear 61, the transmission gear 62 and the driving motor 63 are arranged in the shell 64, so as to effectively protect the driving gear 61, the transmission gear 62 and the driving motor 63 from being damaged by external impurities, and improve the service life and precision thereof.

[0042] Exemplarily, the exhaust fan 3 is detachably mounted on the bottom of the shaft 1. Specifically, the upper end of the air-permeable shell 33 is inserted into the bottom of the shaft 1, and the lower end of the air-permeable shell 33 is located in the tunnel 2. A plurality of buckle grooves 331 are formed on the outer side wall of the lower end of the air-permeable shell 33. A plurality of mounting brackets 34 are arranged on the shaft 1. The upper end of the mounting bracket 34 is connected to the outer wall of the shaft 1 through a spring 35. The middle portion of the mounting bracket 34 is hingedly connected to a fixed bracket 36 on the shaft 1. The lower end of the mounting bracket 34 is buckled in the buckle groove 331. The mounting bracket 34 is convenient for dismounting and repairing the exhaust fan 3. By synchronously pressing the upper end of all the mounting brackets 34, the lower end of the mounting bracket 34 is lifted to separate from the buckle groove 331, and then the air-permeable shell 33 is taken out from the bottom of the shaft 1, so that the exhaust fan 3 can be quickly dismounted. When mounting, the upper end of all the mounting brackets 34 is synchronously pressed, the lower end of the mounting bracket 34 is lifted, the air-permeable shell 33 is inserted into the bottom of the shaft 1, and then the mounting bracket 34 is loosened. The mounting bracket 34 is reset under the elastic force of the spring 35, and the lower end of the mounting bracket 34 is buckled in the buckle groove 331, so as to ensure the stable mounting of the exhaust fan 3.

[0043] Exemplarily, the diameter of the exhaust port 43 is greater than the diameter of the unpowered fan 5, so as to ensure that the exhaust gas in the tunnel 2 can be quickly discharged to the outside.

[0044] Exemplarily, the center height of the unpowered fan 5, the center height of the air inlet 41 and the center height of the air outlet 42 are flush, so that the air inflow can act on the unpowered fan 5 to the maximum extent, and the utilization rate of wind energy is improved.

[0045] Exemplarily, a horn-shaped air guide cylinder is arranged on the air inlet 41, which increases the surface area of the contact airflow, thereby increasing the air volume flowing into the air cap 4, and better guiding the air, so that the exhaust gas in the tunnel 2 can be discharged to the outside more quickly.

[0046] In the description of the application, it should be understood that, unless otherwise clearly specified and limited, the terms "mounting", "connection", "connecting" used in the application should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0047] The above is only the preferred embodiment of the present application, and it should be pointed out that for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and replacements can be made, which should also be considered as the protection scope of the present application.

Claims

1. A tunnel ventilation system, characterized in that, The system includes a vertical shaft and a smoke extraction device. The vertical shaft is installed through the top wall of the tunnel, and its upper part extends to the external ventilation area. The smoke extraction device includes an exhaust fan, a wind cap, a non-powered fan, a drive mechanism, and a controller. The wind cap is located at the upper end of the vertical shaft, and its side wall has an air inlet and an air outlet. The top of the wind cap has an exhaust port. The non-powered fan is located in the inner cavity of the wind cap, which communicates with the inner cavity of the vertical shaft. The top of the wind cap has a wind direction sensor and a wind speed sensor. The drive mechanism is located on the vertical shaft, and it is connected to the wind cap and drives the wind cap to rotate so that the air inlet of the wind cap is opposite to the wind direction. The exhaust fan is located at the bottom of the vertical shaft. The exhaust fan includes fan blades, a fan driver, and a vent housing. The vent housing is located at the bottom of the vertical shaft. The fan driver is mounted on the vent housing. The output end of the fan driver is connected to the fan blades and drives the fan blades to rotate. The exhaust fan, drive mechanism, wind direction detection sensor, and wind speed detection sensor are respectively connected to the controller. When the wind speed detection sensor detects that the actual wind speed is greater than the preset natural exhaust wind speed, the exhaust fan stops and the air inlet of the wind cap is opposite to the wind direction. When the wind speed detection sensor detects that the actual wind speed is less than the preset natural exhaust wind speed, the exhaust fan starts.

2. The tunnel ventilation system as described in claim 1, characterized in that, The preset natural exhaust velocity v is determined based on the ventilation resistance formula. 自然 : Among them, v 自然 Preset natural exhaust wind speed; P 进 The pressure at the air inlet; P 出 ρ is the pressure at the air outlet; ρ is the air density circulating in the external ventilation area; ρ 内 ρ is the density of the air circulating inside the tunnel. 进 ρ is the air density at the air inlet. 出 The air density at the air outlet is ρ; g is the acceleration due to gravity; H is the height difference between the tunnel entrance and the tunnel exit; v a λ represents the actual wind speed inside the tunnel. r D is the coefficient of friction loss of the tunnel wall; L is the length of the tunnel ventilation duct; D r ξ is the diameter of the tunnel cross-section; e This represents the inlet local resistance coefficient.

3. The tunnel ventilation system as described in claim 1, characterized in that, The drive mechanism includes a drive gear, a transmission gear, and a drive motor. The transmission gear is rotatably connected to the upper end of the vertical shaft. The transmission gear has a vent that communicates with the inner cavity of the vertical shaft. The wind cap is connected to the transmission gear. The output end of the drive motor is connected to the drive gear and drives the drive gear to rotate. The drive gear meshes with the transmission gear.

4. The tunnel ventilation system as described in claim 3, characterized in that, The drive mechanism also includes a housing, which is fitted over the upper part of the shaft, and the drive gear, transmission gear and drive motor are all housed inside the housing.

5. The tunnel ventilation system as described in claim 1, characterized in that, The exhaust fan is detachably mounted at the bottom of the shaft.

6. The tunnel ventilation system as described in claim 5, characterized in that, The upper end of the ventilated shell is inserted into the bottom of the shaft, and the lower end of the ventilated shell is located inside the tunnel. The outer side wall of the lower end of the ventilated shell has multiple fastening grooves. Multiple mounting brackets are provided on the shaft. The upper end of the mounting bracket is connected to the outer wall of the shaft by a spring. The middle part of the mounting bracket is hinged to the fixed bracket on the shaft. The lower end of the mounting bracket is fastened in the fastening groove.

7. The tunnel ventilation system as described in claim 1, characterized in that, The diameter of the exhaust port is larger than the diameter of the unpowered fan.

8. The tunnel ventilation system as described in claim 1, characterized in that, The center height of the non-powered fan, the center height of the air inlet, and the center height of the air outlet are all aligned.

9. The tunnel ventilation system as described in claim 1, characterized in that, The air inlet is equipped with a funnel-shaped air guide.

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