Anti-backflow exhaust device

Abstract

The utility model provides an anti-backflow exhaust device which comprises a breather pipe, a protective cover, a flow guide cover, a wind shield and a supporting body, the flow guide cover is arranged between the breather pipe and the protective cover, the flow guide cover is a shell with a streamline-shaped curved surface or an inverted circular truncated cone surface, and the size of the outer edge of an upper port of the breather pipe is smaller than that of the outer edge of a lower port of the flow guide cover. An upper port of the flow guide cover is connected with the lower portion of the protective cover, an upper port of the breather pipe is inserted into a lower port of the flow guide cover, and the breather pipe is connected with the flow guide cover through a supporting body. The flow guide cover and the ventilation pipe have the flow guide and rectification effects on incoming flow and have the suction effect on gas in a structure. And a wind shield is arranged on the outer wall of the breather pipe at the lower part of the lower port of the flow guide cover. The device can utilize wind power, indoor hot air buoyancy or photovoltaic electric power to exhaust, airflow does not flow backwards, and the device is simple in structure, long in service life, low in noise and high in exhaust efficiency. The device is used for places where structures need to be exhausted, ventilated, cooled or dehumidified.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ventilation and exhaust, in particular to an exhaust device using wind power, heat power or photovoltaic power to exhaust and prevent natural wind backflow. BACKGROUND

[0002] With the exhaustion of fossil energy and its pollution to the environment, people pay more and more attention to the utilization of renewable energy, and wind energy, temperature difference energy and photovoltaic power are used in many aspects as renewable energy, which are also applied to ventilation and exhaust.

[0003] Now, several common exhaust devices using natural wind and temperature difference include: (1) spherical exhaust cap, so-called "unpowered fan", which uses natural wind to push the wind wheel to rotate, generates centrifugal force, and adds thermal buoyancy effect of temperature difference between inside and outside of building space to discharge indoor dirty gas. Its advantages: one is beautiful appearance; two is automatic adaptation to horizontal wind. Its disadvantages: one is continuous rotating bearing is easy to damage and produce noise, which needs frequent lubrication and maintenance; two is low exhaust capacity; three is complex manufacturing process and more material consumption; four is easy to produce air flow backflow; five is easy to leak rain; six is need to start wind speed. (2) Venturi tube type exhaust device, which uses low pressure area generated by natural wind through nozzle or Laval nozzle to suck indoor dirty air. Its advantages: one is simple structure and simple manufacturing process; two is low cost. Its disadvantages are need to set wind direction tracking device and need lubrication and maintenance. (3) Wing type exhaust device, for example, the patent number 201010594258.0 of an exhaust device invented by the inventor, which has advantages of: one is simple structure; two is no need for high speed rotation and basically no maintenance. Its disadvantage is to set wind direction tracking device. (4) Wind gathering suction type exhaust device, for example, the patent number 201010241209.9 of a device for generating ordered flow invented by the inventor, which has ventilation function, and its advantages are: one is simple structure without wind device; two is no rotating part and no maintenance. Its disadvantage is complex process, more material consumption, and easy to produce backflow phenomenon when encountering upward vertical flow or upward tangential flow or upward vortex flow. (5) Straight pipe + protective cover type: this is the most traditional exhaust device, which has the advantage of simple structure. Its disadvantages are: one is easy to produce backflow phenomenon when encountering upward vertical flow or upward tangential flow or upward vortex flow; two is low exhaust efficiency. (6) Cylinder shaped air cap: it has realized national standardization product, but its structure is complex and needs to add water droplet water device. It is easy to produce backflow phenomenon when encountering upward vertical flow or upward tangential flow or upward vortex flow. (7) Umbrella shaped air cap: it has realized national standardization product, and its structure is simple, but because the bottom outer edge of umbrella shaped protective cover and air outlet of air cylinder need to leave large flow space, it causes poor effect of rain and snow prevention, insect prevention, bird prevention and miscellaneous prevention. It is easy to produce backflow phenomenon when encountering upward vertical flow or upward tangential flow or upward vortex flow. (8) Cone shaped air cap: it has realized national standardization product, but has poor effect of insect prevention, bird prevention and miscellaneous prevention, and needs to set water device. It is easy to produce backflow phenomenon when encountering upward vertical flow or upward tangential flow or upward vortex flow. (9) Louver type: its advantages are no rotating part and long service life, but it is easy to produce backflow phenomenon when encountering upward vertical flow or upward tangential flow or upward vortex flow, and has poor air exhaust effect.(10) Louver + windbreak type: The advantage is that there are no rotating parts and the performance of preventing backflow of upward wind is good. However, this product is prone to accumulating debris, has a large volume, uses a lot of materials, and is expensive. The external air suction effect is poor. (11) With rectifier type: For example, the exhaust device invented by the inventor: Patent No. 202120414621.X. The advantages are: simple structure, no rotating parts, no maintenance required, long service life, no noise, and no backflow phenomenon will occur within the range of -5° to +90° of the angle between the direction of the incoming wind and the vertical axis of the exhaust device. However, backflow phenomenon is easy to occur when encountering upward vertical flow or upward tangential flow at an angle of less than -5° or upward vortex flow.

[0004] In summary, due to the different structures on the top of buildings and the varying reflected airflow environments of surrounding objects, the direction or organization of airflow through exhaust devices is highly complex when encountering winds from different directions. Sometimes the incoming wind is perpendicular to the vertical axis of the exhaust device, sometimes it flows vertically downwards, sometimes it flows tangentially downwards, sometimes it flows vertically upwards, sometimes it flows tangentially upwards, and sometimes it flows in an upward vortex. If the structural design of the exhaust device is unreasonable, backflow of airflow may occur in certain wind directions. Backflow of airflow will cause the accumulation of polluted gases or smoke inside the building, resulting in serious pollution of the living environment. Summary of the Invention

[0005] The technical problem solved by this invention is to find an exhaust device that can utilize natural wind power, indoor and outdoor thermal pressure difference or photovoltaic power to exhaust air and prevent natural wind backflow.

[0006] To achieve the above objectives and solve the above technical problems, especially to prevent backflow when encountering upward vertical airflow, upward tangential airflow, or upward vortex airflow, and to further improve exhaust efficiency, the technical solution proposed by this invention is as follows:

[0007] An anti-backflow exhaust device includes a vent pipe, a protective cover, a flow guide, and a support. The vent pipe is a vent pipe body with an upper port and a lower port. The protective cover is a cover body. The flow guide is a shell with an upper port and a lower port, and the protective cover is located on the upper port of the flow guide. The outer edge dimension of the upper port of the vent pipe is smaller than the inner edge dimension of the lower port of the flow guide, and the upper port of the vent pipe is placed inside the lower port of the flow guide. The vent pipe and the flow guide are connected by the support. The space inside the vent pipe and between the vent pipe and the flow guide and the protective cover forms an exhaust channel. The lower port of the vent pipe is an air inlet, and the space between the outer wall of the vent pipe and the lower port of the flow guide is an air outlet. The flow guide is a shell with a streamlined curved surface or a truncated cone surface whose upper port cross-sectional area is larger than the lower port cross-sectional area. A wind baffle is provided on the outer wall of the vent pipe below the lower port of the flow guide.

[0008] The protective cover is a cover body, the shape of which includes, but is not limited to, a flat surface, an arc surface, a spherical surface, a hemispherical surface, etc. Its material can be opaque, transparent, or other functional materials. In particular, when the protective cover is made of transparent material, the inner walls of the air guide and the vent pipe are mirrored, and a diffuser is installed at a certain ventilation distance at the lower end of the vent pipe, the device also has a light-focusing and light-guiding function.

[0009] The fairing is a streamlined curved surface or inverted frustum shell with an upper port cross-sectional area larger than the lower port cross-sectional area. This includes, but is not limited to, inverted hemispherical frustum shells, parabolic curved surface shells, or inclined surface shells with upper and lower ports. According to fluid mechanics and aerodynamics principles, different object shapes significantly affect the degree of boundary layer separation, Reynolds coefficient, and drag coefficient of fluid flowing over their surfaces. When fluid flows over a streamlined or inverted frustum surface, boundary layer separation is less likely to occur. In particular, incoming airflow that first flows through the upper part of the fairing is further "impacted" by the following airflow when it reaches the lower part, making separation even more difficult. When the boundary layer does not separate, the pressure drag decreases; the higher the Reynolds coefficient, the lower the drag coefficient. Unseparated airflow and reduced drag improve the utilization efficiency of incoming air.

[0010] The function of the flow deflector is to transform the horizontal one-dimensional or two-dimensional laminar flow into a two-dimensional or three-dimensional flow, i.e., to generate axial flow components and horizontal flow around the flow. The downward axial flow component, through the jet effect generated at the exhaust outlet of the exhaust device, entrains gas from the exhaust channel; simultaneously, as the incoming airflow flows around the outer wall of the vent pipe, a negative pressure zone is generated within a certain range on both sides of the lower part of the vent pipe below the outlet, accelerating the expulsion of gas from the structure under the sweeping action of the incoming airflow. When a temperature difference exists between the inside and outside of the structure, a chimney effect is generated under the action of thermal buoyancy, which can also expel gas from the structure. Fresh air required within the structure enters through other channels within the structure.

[0011] The upper port of the vent pipe is inserted into the lower port of the air guide. Both of them shield and guide the incoming downward and horizontal airflow, and work together to prevent horizontal or downward airflow from entering the exhaust channel, thereby preventing backflow of airflow.

[0012] The wind deflector, when encountering upward vertical, upward tangential, or upward vortex airflow, prevents the airflow from rising and causing backflow. Simultaneously, some airflow, especially vortex airflow, will flow around the perimeter of the wind deflector, creating a negative pressure zone at the air outlet, drawing gas from the ventilation pipe. The wind deflector can be flat or disc-shaped, etc.

[0013] The protective cover can prevent rain, snow, birds, debris, etc. from entering the ventilator or has other functions.

[0014] The ventilator is a tube with an upper and lower port that can be ventilated. It can be that the upper and lower ports are open, or the upper and lower ports of the ventilator are closed, and several vents are opened on the side walls at the upper and lower ports.

[0015] The backflow prevention and exhaust device can be assembled from various components, multiple components can be integrally molded and then assembled, or the entire device can be integrally molded. For example, when the protective cover is spherical and the deflector is inverted frustum-shaped, the two can form an integrally molded spherical shell.

[0016] The device operates as follows: When a horizontal or downward-facing wind blows towards the device, the wind is guided by the deflector. As the wind flows past the lower port of the deflector and the outer wall of the vent pipe, negative pressure and suction are generated. Gas inside the structure enters the vent pipe through the inlet, then passes through the upper port of the vent pipe, the exhaust channel between the deflector and the protective cover, and the vent pipe itself. Within the exhaust channel, the gas expands and depressurizes, finally being swept away by the wind at the lower port of the deflector and expelled into the external space. Simultaneously, the deflector shields the wind, preventing it from entering the vent pipe. When an upward-facing or upward-vortexing wind blows from the outside, the wind is blocked by the baffle plate, and some of the wind flows around the baffle plate. On one hand, the baffle plate prevents the airflow from directly entering the outlet and causing backflow; on the other hand, the surrounding airflow, especially the vortex airflow, creates a negative pressure zone at the outlet, drawing in and sweeping away the gas in the exhaust channel. When there is no wind outside and there is warm air inside, the warm air will generate buoyancy. The warm air rises through the ventilation pipe and is discharged into the outside space through the exhaust channel. The magnitude of the buoyancy follows the element relationship of the gas equation.

[0017] The preferred technical solution of the above-mentioned anti-backflow exhaust device is as follows: the outer edge dimension of the baffle plate is 60% or more of the outer edge dimension of the lower port of the guide shroud; the vertical distance from the upper surface of the baffle plate to the cross section of the lower port of the guide shroud is 10% to 130% of the outer edge dimension of the lower port of the guide shroud; and the axial distance between the upper port of the vent pipe and the lower port of the guide shroud is greater than 5 mm.

[0018] One possible technical solution for the aforementioned backflow prevention exhaust device is to install a gas switching valve within the exhaust channel. The gas switching valve, depending on different operating conditions and structural requirements, can be a manual valve, or an electric, pneumatic, or hydraulic valve; it can be a butterfly valve, a rotary vane valve, or a swing valve. It can be a standard gas switching valve, or a heat-insulating and fire-resistant gas switching valve, etc.

[0019] For any of the aforementioned backflow prevention and exhaust devices, a possible technical solution is to install an electric exhaust fan within the exhaust channel. The electric exhaust fan can be an external rotor fan or an internal rotor fan; the exhaust fan can be installed inside the vent pipe or between the guide shield and the vent pipe. The drive motor can be installed inside the vent pipe or on the upper surface of the protective cover.

[0020] An improved technical solution for any of the aforementioned backflow prevention and exhaust devices is that the vent pipe is an expansion pipe with an upper port cross-sectional area smaller than the lower port cross-sectional area. This structure facilitates the generation of a jet chimney effect in the hot airflow within the structure.

[0021] An improved technical solution for any of the aforementioned backflow prevention exhaust devices is to install a protective net inside the exhaust channel. The protective net prevents the entry of small objects such as insects.

[0022] An improved technical solution for any of the aforementioned anti-backflow exhaust devices is as follows: the vent pipe is a tube with both ends expanded, where the cross-sectional areas of the upper and lower ends are larger than the cross-sectional area of ​​the middle section. This structure facilitates the accumulation and flow of indoor gas and also facilitates the depressurization of the airflow entering the deflector, thereby improving exhaust efficiency.

[0023] For any of the above-mentioned anti-backflow exhaust devices, the available technical solution is: the cover of the protective cover is a photovoltaic power generation panel, and the power output by the photovoltaic power generation panel is connected to the motor of the electric exhaust fan and the LED light via a solar controller (MPPT or PWM), a storage battery.

[0024] For any of the above-mentioned anti-backflow exhaust devices, the available technical solution is: the cover of the protective cover is a photovoltaic power generation panel, and a concentrating protective cover is provided on the photovoltaic power generation panel. The concentrating protective cover has the functions of concentrating light and preventing bird droppings and debris from directly covering the photovoltaic power generation panel and causing a local short circuit in the photovoltaic power generation panel.

[0025] One possible technical solution for the aforementioned anti-backflow exhaust device is: a flexible photovoltaic film is attached to the outer surface of the guide shroud, and the power output from the photovoltaic film is connected to the motor of the electric exhaust fan and LED lights via a solar controller (MPPT or PWM), a storage battery.

[0026] For any of the aforementioned anti-backflow exhaust devices, a suitable technical solution is as follows: A ring-shaped air amplifier or ion fan induced draft head is installed within the exhaust channel. The air jet direction of the ring-shaped air amplifier or ion fan induced draft head faces the exhaust direction. The air inlet of the air amplifier is connected to a compressed air source via a pipeline, or the ion fan induced draft head is connected to a high-voltage power supply. The air amplifier is also known as an air multiplier, bladeless fan, or air inducer. According to the Coanda effect principle, the high-speed gas ejected by the air amplifier can drive the surrounding airflow for exhaust. The air amplifier is a single-wing or double-wing air inducer or a ring-shaped air inducer composed of multiple nozzles. The ion fan generates a high-voltage electric field between two plates using a high-voltage power supply. The movement of ions within the high-voltage electric field generates ion wind, which has a similar function to the air amplifier.

[0027] An improved technical solution for any of the aforementioned anti-backflow exhaust devices is as follows: a guide body is provided on the central axis between the bottom of the protective cover and the upper port of the vent. The guide body is an inverted cone or an inverted arc shape, and the upper part of the inverted cone or inverted arc shape is fixedly connected to the bottom of the protective cover. The guide body has a rectifying and guiding effect on the internal airflow, which can reduce airflow resistance.

[0028] An improved technical solution for any of the above-mentioned anti-backflow exhaust devices is as follows: an electric motor is installed on the top of the protective cover, the shaft of the electric motor passes through the protective cover and is connected to a fan in the exhaust channel, a rain cover is provided on the upper end cover of the electric motor, and a heat insulation pad is provided between the lower end cover of the electric motor and the protective cover.

[0029] An improved technical solution for any of the aforementioned anti-backflow exhaust devices is that the upper end of the vent pipe is an outwardly curled and expanded opening. This structure helps reduce airflow resistance and improve exhaust efficiency.

[0030] For any of the aforementioned anti-backflow venting devices, the available technical solution is as follows: the protective cover of the anti-backflow venting device is provided with a second venting device, the second venting device including a second vent pipe, a second protective cover, a second guide shroud, and a second support body; the second vent pipe is a vent pipe body with an upper port and a lower port; the second protective cover is a cover body; the second guide shroud is a shell with an upper port and a lower port; the second protective cover is located on the upper port of the second guide shroud; the outer edge dimension of the upper port of the second vent pipe is smaller than the inner edge dimension of the lower port of the second guide shroud; the second vent pipe... The upper end of the vent pipe is placed inside the lower end of the second shroud. The lower end of the second vent pipe passes through the protective cover and is fixed to it. The second vent pipe and the second shroud are connected by a second support. The space inside the second vent pipe and between the second vent pipe, the second shroud, and the second protective cover forms a second exhaust channel. The lower end of the second vent pipe is a second air inlet and communicates with the exhaust channel. The space between the outer wall of the second vent pipe and the lower end of the second shroud is a second air outlet. The second shroud is a streamlined curved surface or a truncated cone shell with an upper end cross-sectional area larger than the lower end cross-sectional area. The second exhaust device can increase the exhaust pressure difference and improve the exhaust volume.

[0031] One possible technical solution for the aforementioned anti-backflow exhaust device is to install a second electric exhaust fan within the second exhaust channel. The second electric exhaust fan can be an external rotor fan or an internal rotor fan; the exhaust fan can be installed inside the vent pipe or between the second guide shroud and the second vent pipe.

[0032] An improved technical solution for the aforementioned anti-backflow exhaust device is as follows: a second motor is installed on the top of the second protective cover, the shaft of the second motor passes through the second protective cover and is connected to a fan in the second exhaust channel, a rain cover is provided on the upper end cover of the second motor, and a heat insulation pad is provided between the lower end cover of the motor and the second protective cover.

[0033] One of the above-mentioned anti-backflow exhaust devices is to attach a flexible photovoltaic film to the outer surface of the second guide shroud. The power output from the photovoltaic film is connected to the controller, motor, and LED lights of the second electric exhaust fan via a solar controller (MPPT or PWM) and a battery.

[0034] One of the above-mentioned anti-backflow exhaust devices can be configured as follows: the cover of the second protective cover is a photovoltaic panel, and the power output from the photovoltaic panel is connected to the controller, motor, and LED lights of the second electric exhaust fan via a solar controller (MPPT or PWM), a battery, and the solar panel.

[0035] One of the above-mentioned anti-backflow exhaust devices is a technical solution in which the cover of the second protective cover is a photovoltaic panel, the photovoltaic panel is equipped with a second concentrator, and the power output by the photovoltaic panel is connected to the controller and motor of the electric exhaust fan and LED lights via a solar controller (MPPT or PWM), a battery.

[0036] One alternative technical solution for the aforementioned anti-backflow exhaust device is to install a third exhaust device with the same structure as the second exhaust device on the upper part of the second exhaust device.

[0037] One possible technical solution for the aforementioned anti-backflow exhaust device is to install a lightning rod or mascot design on the top of the second protective cover.

[0038] An improved technical solution for any of the above-mentioned anti-backflow exhaust devices is that the surface ripples of the streamlined curved shell can be a smooth surface, a lotus seedpod shape, a plum blossom shape, a concave arc shape, a polygonal surface, etc., or various painted patterns.

[0039] Beneficial effects: (1) In terms of structural performance, the device has a simple structure and can realize exhaust using natural wind power, heat, and photovoltaic power, saving mains electricity. In pure wind and heat mode, there are no rotating parts and no need for wind direction tracking device, which can adapt to high wind speed loads; it can achieve the goals of low noise, no leakage of rain and snow, no nesting by birds, no maintenance, and long service life. (2) In terms of exhaust performance, the device starts with a very low wind speed. According to actual testing, for example, the effective diameter of the ventilation pipe is 160mm. Compared with the commonly used spherical rotating "non-powered fan" with an effective diameter of 160mm, the "non-powered fan" can only start exhaust when the external wind speed is 1.2m / s, while the device can detect exhaust with an anemometer when the external wind speed is 0.25m / s, and the exhaust speed reaches 0.1m / s. The exhaust volume of the device in the wind speed range of 0.25m / s to 35m / s is 1.3 times that of the "non-powered fan". (3) In terms of preventing backflow, the device has the ability to prevent backflow of external airflow within the range of -90° to +90° in the vertical direction. Attached Figure Description

[0040] Appendix Figure 1 This is a schematic diagram illustrating the structural principle of an anti-backflow exhaust device according to the present invention.

[0041] Figure 1 In the middle: 1. Ventilation pipe, 2. Protective cover, 3. Support body, 4. Flow deflector, 5. Wind deflector, 6. Structure.

[0042] Solid lines with arrows represent external flow streamlines; single-dotted lines with arrows represent gas streamlines within the structure; double-dotted lines with arrows represent external tangential or vortex flow.

[0043] Appendix Figure 2 This is a schematic diagram illustrating another structural principle of an anti-backflow exhaust device according to the present invention.

[0044] Figure 2 In the middle: 1. Vent pipe, 2. Protective cover, 3. Support body, 4. Radiator, 5. Wind deflector, 6. Structure, 1b. Second vent pipe, 2b. Photovoltaic panel, 3b. Second support body, 4b. Second radiator, 7b. Concentrating protective cover, 8b. DC motor, 9b. Fan.

[0045] Solid lines with arrows represent external flow streamlines; single-dotted lines with arrows represent gas streamlines within a structure; double-dotted lines with arrows represent external tangential or vortex flow; and dashed lines with arrows represent light rays. Detailed Implementation

[0046] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The following embodiments are intended to illustrate the present invention, but not to further limit the present invention.

[0047] Example 1:

[0048] like Figure 1 The illustrated anti-backflow exhaust device includes a vent pipe 1, a protective cover 2, a support body 3, a flow guide 4, and a baffle plate 5. The lower part of the vent pipe 1 is fixedly sealed to a structure 6. The vent pipe 1 is a body with an outwardly expanding upper and lower port. The protective cover 2 is an arc-shaped cover, and its outer diameter is twice the diameter of the vent pipe 1. The flow guide 4 is a streamlined curved shell with an upper and lower port. The diameter of the upper port of the flow guide 4 is twice the diameter of the vent pipe 1, and the diameter of the lower port is 1.5 times the diameter of the vent pipe 1. The protective cover 2 is located on the upper port of the flow guide 4. The outer diameter of the upper port of the vent pipe 1 is smaller than the inner diameter of the lower port of the flow guide 4. The upper port of the vent pipe 1 is inserted into the lower port of the flow guide 4, with an insertion height of one-third of the diameter of the vent pipe 1. The vent pipe 1 and the guide shroud 4 are connected by a support body 3; the space inside the vent pipe 1 and between the vent pipe 1 and the guide shroud 4 and the protective cover 2 forms an exhaust channel. The lower end of the vent pipe 1 is the air inlet, and the space between the outer wall of the vent pipe 1 and the lower end of the guide shroud 4 is the air outlet; a baffle plate 5 is provided on the outer wall of the vent pipe 1 at the lower end of the guide shroud 4. The outer diameter of the baffle plate 5 is equal to the diameter of the lower end of the guide shroud 4, and the vertical distance from the upper surface of the baffle plate 5 to the cross section of the lower end of the guide shroud 4 is equal to 60% of the outer diameter of the lower end of the guide shroud 4.

[0049] The upper port of the vent pipe 1 is inserted into the lower port of the flow guide shroud 4. Both of them have the function of shielding and guiding the incoming downward airflow and horizontal airflow, and work together to prevent horizontal or downward airflow from entering the exhaust channel, thereby preventing backflow of airflow.

[0050] The baffle 5 serves to prevent airflow from rising when it encounters upward vertical flow, upward tangential flow, or upward vortex flow, thus preventing backflow. At the same time, some airflow will flow around the baffle 5, creating a negative pressure zone at the air outlet, which will draw in and sweep away the gas in the vent pipe.

[0051] The function of the flow deflector 4 is to transform the one-dimensional or two-dimensional horizontal inflow into a two-dimensional or three-dimensional flow, i.e., to generate an axial flow component and a horizontal flow component. The downward axial flow component, through the jet effect generated at the exhaust outlet of the exhaust device, will entrain the gas in the exhaust channel. Simultaneously, the external airflow surrounds the outer wall of the ventilation pipe 1, creating a negative pressure zone within a certain range on both sides of the lower part of the ventilation pipe 1 at the outlet, accelerating the expulsion of gas from the structure 6. When there is a temperature difference between the inside and outside of the structure 6, a chimney effect is generated under the action of thermal buoyancy, which can also expel gas from the structure 6. The fresh air required in the structure 6 enters from other channels of the structure 6.

[0052] The protective cover 2 can prevent rain, snow, birds, debris and other objects from entering the ventilator.

[0053] The device operates as follows: When a horizontal or downward-facing wind blows towards the device, the wind is guided by the guide hood 4. As the wind flows past the lower port of the guide hood 4 and the outer wall of the vent pipe 1, negative pressure and suction are generated. The gas inside the structure 6 enters the vent pipe 1 through the inlet, then passes through the upper port of the vent pipe 1, the exhaust channel between the guide hood 4 and the protective cover 2, and finally is swept away by the external wind from the lower port of the guide hood 1 into the external space. At the same time, the guide hood 4 shields the wind, preventing it from entering the vent pipe 1. When there is an upward-facing or upward-vortexing wind, the wind is blocked by the baffle 5, and some of the wind flows around to the periphery of the baffle 5. On the one hand, the baffle 1 prevents the airflow from directly entering the outlet and causing backflow; on the other hand, the airflow around to the periphery of the baffle 5 creates a negative pressure zone at the outlet, drawing in the gas from the exhaust channel. When there is no wind outside and there is warm air inside, the warm air will generate buoyancy. The warm air rises through the ventilation pipe 1 and is discharged into the outside space through the exhaust channel. The magnitude of the buoyancy follows the element relationship of the gas equation.

[0054] Example 2:

[0055] like Figure 2The illustrated anti-backflow exhaust device includes a vent pipe 1, a protective cover 2, a support body 3, a flow guide 4, a wind deflector 5, a second vent pipe 1b, a photovoltaic panel 2b, a second support body 3b, a second flow guide 4b, a concentrating protective cover 7b, a DC motor 8b, and a fan 9b. The lower part of the vent pipe 1 is fixedly sealed to a structure 6. The vent pipe 1 is a pipe with an upper port and a lower port. The protective cover 2 is a photovoltaic panel. The flow guide 4 is an inverted frustum shell with an upper port and a lower port, with the protective cover 2 located on the upper port of the flow guide 4. The outer diameter of the upper port of the vent pipe 1 is smaller than the inner diameter of the lower port of the flow guide 4, and the upper port of the vent pipe 1 is placed inside the lower port of the flow guide 4. The vent pipe 1 and the flow guide 4 are connected by the support body 3. The space between the vent pipe 1 and the guide shroud 4 and the protective cover 2 forms an exhaust channel. The lower end of the vent pipe 1 is the air inlet, and the space between the outer wall of the vent pipe 1 and the lower end of the guide shroud 4 is the air outlet. A baffle plate 5 is provided on the outer wall of the vent pipe 1 at the lower end of the guide shroud 4. The outer diameter of the baffle plate 5 is larger than the diameter of the lower end of the guide shroud 4. The vertical distance from the upper surface of the baffle plate 5 to the cross section of the lower end of the guide shroud 4 is equal to 90% of the outer diameter of the lower end of the guide shroud 4. The second vent pipe 1b is a vent pipe body with an upper port and a lower port. The second protective cover 2b is a photovoltaic power generation panel. The second guide shroud 4b is an inverted frustum shell with an upper port and a lower port. The second protective cover 2b is located on the upper port of the second guide shroud 4b. The outer edge dimension of the upper port of the second vent pipe 1b is smaller than the inner edge dimension of the lower port of the second guide shroud 4b. The upper port of the second vent pipe 1b is placed inside the lower port of the second guide shroud 4b. The lower port of the second vent pipe 1b passes through the protective cover 2 and is fixed to the protective cover 2. The second vent pipe 1b and the second guide shroud 4b are connected by the second support body 3b. The space inside the second vent pipe 1b and between the second vent pipe 1b, the second guide shroud 4b, and the second protective cover 2b forms a second exhaust channel. The lower port of the second vent pipe 1b is the second air inlet and communicates with the exhaust channel. The space between the outer wall of the second vent pipe 1b and the lower port of the second guide shroud 4b is the second air outlet. The DC motor 8b is fixed to the upper port of the second vent pipe 1b by a motor bracket. The fan 9b is located inside the upper port of the second vent pipe 1b, and the shaft of the DC motor 8b is connected to the fan 9b.

[0056] External sunlight shines through the concentrator shield 7b onto the photovoltaic panel 2b to generate electricity, which then drives the DC motor 8b and fan 9b to rotate and increase exhaust. The electricity generated by the photovoltaic panel 2b can also be transmitted through a solar controller (MPPT or PWM) and a battery (not shown in the figure) to drive the DC motor 8b and fan 9b to rotate and increase exhaust.

[0057] In the operation of Example 2, in addition to the gas being discharged from the lower port of the deflector 4 of the structure 6, as in Example 1, a portion of the gas entering the deflector 4 from the structure 6 will also enter the upper deflector 4b, and be discharged to the external space under the action of external wind force, the buoyancy of hot gas inside the structure 6, or the DC motor 8b and fan 9b. The upper deflector 4b can increase the exhaust pressure difference and improve the exhaust volume. The functions and working processes of the other components in Example 2 are basically the same as in Example 1, and will not be described again here.

[0058] Although the invention has been described in conjunction with preferred embodiments, it is not limited to the specific structural forms set forth herein and in the accompanying drawings. Rather, it is intended to cover various alternatives, equivalents, and devices derived from recombinations of various feature elements within the scope of the invention as defined by the claims.

Claims

1. A backflow prevention and exhaust device, comprising a vent pipe, a protective cover, a flow guide, and a support body, wherein the vent pipe is a vent pipe body having an upper port and a lower port, the protective cover is a cover body, and the flow guide is a shell having an upper port and a lower port, the protective cover being located on the upper port of the flow guide; the outer edge dimension of the upper port of the vent pipe is smaller than the inner edge dimension of the lower port of the flow guide, the upper port of the vent pipe is placed inside the lower port of the flow guide, and the vent pipe and the flow guide are connected by the support body; the space inside the vent pipe and between the vent pipe and the flow guide and the protective cover forms an exhaust channel, the lower port of the vent pipe is an air inlet, and the space between the outer wall of the vent pipe and the lower port of the flow guide is an air outlet; the flow guide is a shell with a streamlined curved surface or a truncated cone surface whose upper port cross-sectional area is larger than the lower port cross-sectional area; characterized in that: A baffle plate is provided on the outer wall of the vent pipe at the lower part of the lower port of the shroud.

2. The anti-backflow exhaust device according to claim 1, characterized in that: The outer edge dimension of the wind deflector is 60% or more of the outer edge dimension of the lower port of the shroud; the vertical distance from the upper surface of the wind deflector to the cross-section of the lower port of the shroud is 10% to 130% of the outer edge dimension of the lower port of the shroud; and the axial distance between the upper port of the vent pipe and the lower port of the shroud is greater than 5 mm.

3. The anti-backflow exhaust device according to claim 1, characterized in that: A gas switching valve is installed in the exhaust passage.

4. A backflow prevention and exhaust device according to claim 1, 2, or 3, characterized in that: An electric exhaust fan is installed in the exhaust channel.

5. A backflow prevention and exhaust device according to claim 1, 2, or 3, characterized in that: A protective net is installed inside the exhaust channel.

6. The anti-backflow exhaust device according to claim 4, characterized in that: The cover of the protective cover is a photovoltaic power generation panel. The power output from the photovoltaic power generation panel is connected to a solar controller, a storage battery, an electric exhaust fan, and an electric motor.

7. A backflow prevention and exhaust device according to claim 1, 2, or 3, characterized in that: An annular air amplifier or ion fan induced draft head is provided in the exhaust channel. The air jet direction of the annular air amplifier or ion fan induced draft head is facing the exhaust direction. The air inlet of the air amplifier is connected to a compressed air source or the ion fan induced draft head is connected to a high-voltage power supply through a pipeline.

8. The anti-backflow exhaust device according to claim 4, characterized in that: A guide fluid is provided on the central axis between the bottom of the protective cover and the upper port of the vent. The guide fluid is an inverted cone or an inverted arc shape, and the upper part of the inverted cone or inverted arc shape is fixedly connected to the bottom of the protective cover.

9. A backflow prevention and exhaust device according to claim 1, 2, or 3, characterized in that: An electric motor is installed on the top of the protective cover. The shaft of the electric motor passes through the protective cover and is connected to a fan in the exhaust channel. A rain cover is provided on the upper end cover of the electric motor, and a heat insulation pad is provided between the lower end cover of the electric motor and the protective cover.

10. A backflow prevention and exhaust device according to claim 1, 2, or 3, characterized in that: The protective cover of the anti-backflow exhaust device is equipped with a second exhaust device, which includes a second vent pipe, a second protective cover, a second guide shroud, and a second support. The second vent pipe is a vent pipe body with an upper port and a lower port. The second protective cover is a cover body. The second guide shroud is a shell with an upper port and a lower port. The second protective cover is located on the upper port of the second guide shroud. The outer edge dimension of the upper port of the second vent pipe is smaller than the inner edge dimension of the lower port of the second guide shroud. The upper port of the second vent pipe is positioned on the second guide shroud. Inside the lower port of the flow shield, the lower port of the second vent pipe passes through the protective cover and is fixed to the protective cover. The second vent pipe and the second flow shield are connected by a second support. The space inside the second vent pipe and between the second vent pipe, the second flow shield, and the second protective cover forms a second exhaust channel. The lower port of the second vent pipe is a second air inlet and communicates with the exhaust channel. The space between the outer wall of the second vent pipe and the lower port of the second flow shield is a second air outlet. The second flow shield is a shell with a streamlined curved surface or a truncated cone surface whose upper port cross-sectional area is larger than the lower port cross-sectional area.

Images