Tunnel exhaust system

Abstract

The invention relates to the technical field of tunnel ventilation and discloses a tunnel exhaust system, a vertical shaft is arranged on the top wall of a tunnel in a penetrating mode, a smoke exhaust device comprises an exhaust fan, an air cap, an unpowered fan, a driving mechanism and a controller, the air cap is arranged at the upper end of the vertical shaft, an air inlet and an air outlet are formed in the side wall of the air cap, and an exhaust port is formed in the top of the air cap; the unpowered fan is arranged in an inner cavity of the hood, the inner cavity of the hood is communicated with an inner cavity of the vertical shaft, and the driving mechanism drives the hood to rotate to enable an air inlet of the hood to be opposite to the wind direction; the exhaust fan is arranged at the bottom of the vertical shaft; the fan driver drives fan blades to rotate; when the air speed detection sensor detects that the actual air speed is larger than the preset natural exhaust air speed, the exhaust fan stops pausing, and the air inlet of the hood is opposite to the air direction. The exhaust fan can be started and stopped according to the actual wind speed, wind energy is fully used as power to drive the unpowered fan, air circulation in the tunnel is guaranteed, electric energy consumption is reduced, and energy conservation and environmental protection are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel ventilation, and in particular to a tunnel exhaust system. Background Art

[0002] Due to the limited space in the tunnel, fresh air circulation is difficult, and various harmful gases accumulate over a long period of time, causing harm to people's bodies. Usually, fans are placed underground to promote the discharge of harmful gases from the tunnel, but the long-term use of motors to power the fans causes a great loss of electricity. In addition, there is no sunlight in the tunnel, and solar energy cannot be used to store electricity. In the long run, the loss of electricity will cause great economic consumption and does not meet the requirements of energy conservation and environmental protection. Summary of the invention

[0003] The purpose of the present invention is to provide a tunnel exhaust system that can start and stop the exhaust fan according to the actual wind speed, fully utilize wind energy as power to drive the unpowered fan, ensure air circulation inside the tunnel, reduce power consumption, and save energy and protect the environment.

[0004] In order to achieve the above-mentioned object, the present invention provides a tunnel exhaust system, comprising a shaft and a smoke exhaust device, wherein the shaft is arranged through the top wall of the tunnel, and the upper part of the shaft extends to the external ventilation area, and the smoke exhaust device comprises an exhaust fan, a hood, a non-powered fan, a driving mechanism and a controller, wherein the hood is arranged at the upper end of the shaft, an air inlet and an air outlet are arranged on the side wall of the hood, an exhaust port is arranged on 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 shaft, a wind direction detection sensor and a wind speed detection sensor are arranged on the top of the hood, and the driving mechanism is arranged on the shaft, and the driving mechanism is connected to 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 shaft, and comprises fan blades, a fan driver and a breathable housing. The breathable housing is arranged at the bottom of the shaft, and the fan driver is installed on the breathable housing. The output end of the fan driver is connected to the fan blades and drives the fan blades to rotate.

[0006] The exhaust fan, driver, 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 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 solution of the present invention, the preset natural exhaust wind speed v is determined according to the ventilation resistance formula 自然 :

[0008]

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

[0010] As a preferred solution of the present invention, the driving mechanism includes a driving gear, a transmission gear and a driving motor. The transmission gear is rotatably connected to the upper end of the shaft. The transmission gear is provided with a vent connected to the inner cavity of the shaft. The hood 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. The driving gear is meshed with the transmission gear.

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

[0012] As a preferred solution of the present invention, the exhaust fan is detachably installed at the bottom of the shaft.

[0013] As a preferred solution of the present invention, the upper end of the breathable shell is inserted into the bottom of the shaft, the lower end of the breathable shell is located in the tunnel, a plurality of buckle grooves are provided on the outer side wall of the lower end of the breathable shell, a plurality of mounting brackets are provided 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 hinged 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 solution of the present invention, the diameter of the exhaust port is larger than the diameter of the unpowered fan.

[0015] As a preferred solution of the present invention, 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] As a preferred solution of the present invention, a trumpet-shaped air guide tube is provided on the air inlet.

[0017] Compared with the prior art, the tunnel exhaust system according to the embodiment of the present invention has the following beneficial effects:

[0018] The present invention can sense the wind direction at any time through the wind direction detection sensor on the hood, and drives the hood to rotate through the driving mechanism so that the air inlet of the hood faces the incoming 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 discharge the gas inside the tunnel to the exhaust port, so as to realize tunnel ventilation; 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 by the air to rotate to discharge the exhaust gas and smoke inside the tunnel to the exhaust port, so as to realize air circulation inside the tunnel, make full use of wind energy as power, improve the efficiency of tunnel ventilation, do not need to use the exhaust fan for tunnel ventilation for a long time, reduce power consumption, and save energy and protect the environment. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0020] Figure 2 is a schematic diagram of the structure of a tunnel exhaust system provided by an embodiment of the present invention in a tunnel;

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

[0022] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like used in the present invention to indicate the orientation or position relationship is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0024] like Figure 1 and Figure 2 As shown, a preferred embodiment of a tunnel exhaust system provided by the present invention comprises a shaft 1 and a smoke exhaust device, wherein the shaft 1 is arranged through the top wall of the tunnel 2, and the upper part of the shaft 1 extends to the external ventilation area, and the smoke exhaust device comprises an exhaust fan 3, a hood 4, a non-powered fan 5, a driving mechanism 6 and a controller, wherein the hood 4 is arranged at the upper end of the shaft 1, and an air inlet 41 and an air outlet 42 are arranged on the side wall of the hood 4, and an exhaust port 43 is arranged on the top of the hood 4, and the non-powered fan 5 is arranged in the inner cavity of the hood 4, and the inner cavity of the hood 4 is communicated with the inner cavity of the shaft 1, and a wind direction detection sensor 44 and a wind speed detection sensor are arranged on the top of the hood 4, and the driving mechanism 6 is arranged on the shaft 1, and the driving mechanism 6 is connected to 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, and the exhaust fan 3 includes a fan blade 31, a fan driver 32 and a breathable housing 33. The breathable housing 33 is arranged at the bottom of the shaft 1, and the fan driver 32 is installed on the breathable housing 33. The output end of the fan driver 32 is connected to 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, driver, wind direction detection sensor 44, and wind speed detection sensor are respectively connected to the controller. The controller can operate the driving mechanism 6 according to the wind direction feedback from 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 feedback from the wind speed detection sensor. When the wind speed detection sensor detects that the actual wind speed 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 wind speed detection sensor detects that the actual wind speed is less than the preset natural exhaust wind speed, the exhaust fan 3 is started.

[0027] The present invention can sense the wind direction at any time through the wind direction detection sensor 44 on the hood 4, and drives the hood 4 to rotate through the driving mechanism 6 so that the air inlet 41 of the hood 4 faces the incoming 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 discharge the gas inside the tunnel 2 to the exhaust port 43, so as to realize ventilation of the tunnel 2; when the actual wind speed is greater than or equal to the preset natural exhaust wind speed, the exhaust fan 3 is paused, and the unpowered fan 5 is driven by the air to rotate and work, so as to discharge the exhaust gas and smoke inside the tunnel 2 to the exhaust port 43, so as to realize the air circulation inside the tunnel 2, make full use of wind energy as power, improve the ventilation efficiency of the tunnel 2, do not need to use the exhaust fan 3 for ventilation of the tunnel 2 for a long time, reduce power consumption, save energy and protect the environment.

[0028] As a preferred solution of the present invention, the preset natural exhaust wind speed v is determined according to the ventilation resistance formula 自然 :

[0029]

[0030] Among them, v 自然 is the preset natural exhaust wind speed; P 进 is the pressure at the air inlet 41; P 出 is the pressure at the air outlet 42; ρ is the air density circulating in the external ventilation area; ρ 内 is the air density circulating in tunnel 2; ρ 进 is the air density at the air inlet 41; ρ 出 is the air density at the air outlet 42; g is the acceleration due to gravity; H is the height difference between the entrance of tunnel 2 and the exit of tunnel 2. If tunnel 2 is a horizontal tunnel 2, H = 0; v a is the actual wind speed in tunnel 2; 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 cross-sectional diameter of tunnel 2; ξ e is the inlet local resistance coefficient; and r and e The parameters of tunnel 2 are fixed. Specifically, pressure sensors are respectively set at the air inlet 41 and the air outlet 42 to detect their pressures; air density sensors are respectively set at the air inlet 41 and the air outlet 42 to detect their air densities, and air density sensors are set outside the hood 4 to detect the air density circulating in the external ventilation area; air density sensors are set inside the tunnel 2 to detect the air density circulating in the tunnel 2.

[0031] Specifically, the complete wind speed calculation is as follows: Let the height difference between the entrance and exit of Tunnel 2 be H. When H is small, the atmospheric density can be regarded as a constant. Under ideal conditions, assuming that the atmosphere is stationary, the atmospheric pressures at the entrance of Tunnel 2 (the entrance of Tunnel 2 and the exit of Tunnel 2) are P1 (low end) and P2 (high end), respectively. The pressure difference between the two is called the static pressure difference.

[0032] P1-P2=ρgH

[0033] The airflow pressure difference between the inlet and outlet of Tunnel 2 is called the excess static pressure difference, expressed as Δ P express:

[0034] Δ P =P1-P2-ρgH

[0035] Taking the atmospheric pressure P2 at the high end hole as the reference point, Δ P It represents the excess static pressure difference between the atmospheric pressure P1 at the lower end hole and the atmospheric pressure P2 at the higher end hole. When the wind flows from the lower end hole to the higher end hole, Δ P >0; otherwise, Δ P <0.

[0036] For a general tunnel 2, when the comprehensive pressure difference between the two openings Δ P The ventilation resistance formula can be used to calculate the preset natural exhaust wind speed v 自然 ,have:

[0037]

[0038] Among them, v n is the wind speed in tunnel 2 under ideal conditions.

[0039] Exemplarily, the driving mechanism 6 includes 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 a vent connected to the inner cavity of the shaft 1. The hood 4 is connected to the transmission gear 62. The output end of the driving motor 63 is connected to the driving gear 61 and drives the driving gear 61 to rotate. The driving gear 61 is meshed with the transmission gear 62, so that the driving motor 63 drives the driving gear 61 to rotate, thereby driving the transmission gear 62 to rotate, and the transmission gear 62 synchronously drives the hood 4 to rotate.

[0040] Exemplarily, the driving mechanism 6 also includes a shell 64, which is sleeved on the upper part of the shaft 1. The driving gear 61, the transmission gear 62 and the driving motor 63 are all arranged in the shell 64, which effectively protects the driving gear 61, the transmission gear 62 and the driving motor 63 from being damaged by external impurities, thereby improving their service life and accuracy.

[0041] Exemplarily, the exhaust fan 3 is detachably mounted at the bottom of the shaft 1. Specifically, the upper end of the air-permeable housing 33 is inserted into the bottom of the shaft 1, and the lower end of the air-permeable housing 33 is located in the tunnel 2. A plurality of buckle grooves 331 are provided on the outer side wall of the lower end of the air-permeable housing 33. A plurality of mounting brackets 34 are provided on the shaft 1. The upper ends of the mounting brackets 34 are connected to the outer wall of the shaft 1 through springs 35. The middle part of the mounting bracket 34 is hinged to the fixed bracket 36 on the shaft 1. The lower end of the mounting bracket 34 is buckled in the buckle groove 331. To facilitate the disassembly, assembly and maintenance of the exhaust fan 3, the upper ends of all the mounting brackets 34 are pressed down simultaneously so that the lower ends of the mounting brackets 34 are tilted and separated 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 disassembled; during installation, the upper ends of all the mounting brackets 34 are pressed down simultaneously so that the lower ends of the mounting brackets 34 are tilted, and the air-permeable shell 33 is inserted at the bottom of the shaft 1, and then the mounting brackets 34 are released. The mounting brackets 34 are reset under the elastic force of the springs 35, and the lower ends of the mounting brackets 34 are buckled in the buckle groove 331 to ensure the stable installation of the exhaust fan 3.

[0042] Exemplarily, the diameter of the exhaust port 43 is larger than the diameter of the unpowered fan 5 , which can ensure that the exhaust gas and smoke in the tunnel 2 can be quickly discharged to the outside.

[0043] 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 aligned so that the incoming air can act on the unpowered fan 5 to the greatest extent, thereby improving the utilization rate of wind energy.

[0044] Exemplarily, the air inlet 41 is provided with a trumpet-shaped air guide tube, which increases the surface area in contact with the wind flow, thereby increasing the amount of wind flowing into the wind hood 4, and can better guide the wind, so that the exhaust gas and smoke in the tunnel 2 can be discharged to the outside faster.

[0045] In the description of the present invention, it should be understood that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" used in the present invention should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A tunnel exhaust system, characterized in that: It comprises a shaft and a smoke exhaust device, wherein the shaft is arranged through the top wall of the tunnel, the upper part of the shaft extends to the external ventilation area, the smoke exhaust device comprises an exhaust fan, a hood, an unpowered fan, a driving mechanism and a controller, the hood is arranged at the upper end of the shaft, an air inlet and an air outlet are arranged on the side wall of the hood, an exhaust port is arranged on the top of the hood, the unpowered fan is arranged in the inner cavity of the hood, the inner cavity of the hood is communicated with the inner cavity of the shaft, a wind direction detection sensor and a wind speed detection sensor are arranged on the top of the hood, the driving mechanism is arranged on the shaft, the driving mechanism is connected to the hood and 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 shaft, and comprises fan blades, a fan driver and a breathable housing. The breathable housing is arranged at the bottom of the shaft, and the fan driver is installed on the breathable housing. The output end of the fan driver is connected to the fan blades and drives the fan blades to rotate. The exhaust fan, driver, 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 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.

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

3. The tunnel exhaust system according to claim 1, characterized in that: The driving mechanism includes a driving gear, a transmission gear and a driving motor. The transmission gear is rotatably connected to the upper end of the shaft. The transmission gear is provided with a vent connected to the inner cavity of the shaft. The hood 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. The driving gear is meshed with the transmission gear.

4. The tunnel exhaust system according to claim 3, characterized in that: The driving mechanism also includes a shell, which is sleeved on the upper part of the shaft, and the driving gear, transmission gear and driving motor are all arranged in the shell.

5. The tunnel exhaust system according to claim 1, characterized in that: The exhaust fan is detachably mounted at the bottom of the shaft.

6. The tunnel exhaust system according to claim 5, characterized in that: The upper end of the breathable shell is inserted into the bottom of the shaft, the lower end of the breathable shell is located in the tunnel, a plurality of buckle grooves are provided on the outer side wall of the lower end of the breathable shell, a plurality of mounting brackets are provided 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 hinged to the fixed bracket on the shaft, and the lower end of the mounting bracket is buckled in the buckle groove.

7. The tunnel exhaust system according to claim 1, characterized in that: The diameter of the exhaust port is greater than the diameter of the unpowered fan.

8. The tunnel exhaust system according to claim 1, characterized in that: The center height of the unpowered fan, the center height of the air inlet and the center height of the air outlet are flush.

9. The tunnel exhaust system according to claim 1, characterized in that: A trumpet-shaped air guide tube is arranged on the air inlet.

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