WO2018209943A1

WO2018209943A1 - Fresh air ventilator having automatic control function

Info

Publication number: WO2018209943A1
Application number: PCT/CN2017/116360
Authority: WO
Inventors: 戴文; 朱蓓蕾; 薛健
Original assignee: 昆山斯莱姆节能科技有限公司
Priority date: 2017-05-13
Filing date: 2017-12-15
Publication date: 2018-11-22
Also published as: CN106989457B; DE212017000173U1; CN106989457A

Abstract

A fresh air ventilator having an automatic control function, comprising a housing, an outdoor air inlet (1), an outdoor air outlet (2), an indoor air return opening (3), and an indoor air supply opening (4). A fresh air channel and an air return channel are provided in the housing in an intersecting manner; the two ends of the fresh air channel are respectively in communication with a fresh air filter element (5) and an air inlet draught fan (6); the fresh air filter element (5) is in communication with the outdoor air inlet (1); the air inlet draught fan (6) is in communication with the indoor air supply opening (4); the two ends of the air return channel are respectively in communication with the indoor air return opening (3) and the air return draught fan (8); the air return draught fan (8) is in communication with the indoor air return opening (3); a heat exchange core (9) is provided on the intersection of the fresh air channel and the air return channel; a PLC (13), an environment monitoring module (11), and an external connection control panel (12) are also provided. By monitoring the temperature, the humidity, CO2, PM2.5, VOC, etc. in the air, and then according to the detected data, automatically adjusting a corresponding operating mode, the degree of automation is high, and the purification effect of a fresh air purifier is improved.

Description

A new fan with automatic control function

Technical field

The invention relates to the technical field of air purification, in particular to a new fan with automatic control function.

Background technique

With the continuous advancement of industrial automation and the continuous improvement of people's quality of life, people's requirements for their living environment are constantly improving, and air quality is an important indicator of the quality of the environment, which directly affects people's healthy life. The fog and dust in the air, together with the environmental pollution caused by interior decoration, have become a social problem. These pollution gases have been scientifically proven to have a great impact on the human body, easily leading to respiratory diseases and cancer. Leukemia and neurological diseases are especially harmful to pregnant women, children and the elderly. Therefore, it is very important for the purification of indoor air.

The new fan equipped with the heat exchange core is a kind of fresh air that is filtered, purified, and heat-exchanged and sent into the room. At the same time, the indoor polluted harmful gas is heat-exchanged and discharged to the outside, and the indoor temperature is discharged. An energy-efficient, environmentally-friendly, high-tech product that is largely unaffected by fresh air.

Some of the new types of wind turbines currently on the market are complex in structure, unreasonable in layout, inconvenient to use, and are made of aluminum heat exchange core. The aluminum heat exchange core body produces condensed water on the surface after working for a period of time, affecting heat exchange. The working effect of the core body even damages the heat exchange core body and shortens the service life of the new fan. In order to solve this problem, a draft water tank is arranged on the heat exchange core to discharge the condensed water, but this method not only increases the cost but also the structure. In addition, some of the above-mentioned new fans sold on the market have no filter elements in the indoor air return, and the polluted particles contained in the indoor return air enter the heat exchange core, which easily damages the heat exchange core and shortens the ceiling type new fan. Service life.

In addition, most of the existing new fans of this type only continue to operate under the selected operating mode when people open, and do not have the function of automatically adjusting the operating mode of the new fan according to the data changes of pollutants in the air, and cannot adapt to various kinds of people. The need to purify the air is not conducive to people's health.

Summary of the invention

The technical problem mainly solved by the invention is to provide a new fan with automatic control function, which can monitor the temperature and humidity, CO ₂ , PM2.5 and VOC in the air, and then automatically adjust the corresponding data according to the monitored data. Operating mode, and has a high heat exchange rate and air purification rate, convenient for people to use, compact structure design, reasonable layout, long service life, and low cost.

In order to solve the above technical problem, a technical solution adopted by the present invention is to provide a new fan with an automatic control function, including a casing, an outdoor air inlet, an outdoor air outlet, an indoor air return port, and an indoor air supply port, the outdoor The air outlet and the outdoor air inlet are respectively located at a left end of the housing, and the indoor air return port and the indoor air supply port are respectively located at a right end of the housing;

A fresh air passage and a return air passage are disposed in the housing, and a fresh air filter member and an air inlet fan are respectively disposed at two ends of the fresh air passage, and the fresh air filter member is connected to the outdoor air inlet, the air inlet fan Communicating with the indoor air supply port, one end of the return air passage is provided with a return air fan, the return air fan is connected with the outdoor air exhaust port, and the other end of the return air passage is connected with the indoor air return port The filter surface of the fresh air filter has a predetermined angle with the gas flow cross section;

A heat exchange core is further disposed at an intersection of the fresh air passage and the return air passage, and the heat exchange core includes a fresh air passage and a return air passage, and the air inlet of the new air passage passes The fresh air filter is connected to the outdoor air inlet, and the air outlet of the new air passage is connected to the indoor air supply through the air inlet fan, and the air inlet of the return air passage is connected with the indoor air return port, and the air outlet of the return air passage passes back The air blower is connected to the outdoor air outlet, and the fresh air tunnel and the return air passage are alternately stacked from bottom to top by a plurality of ventilation members and a plurality of sealing members, and the fresh air tunnel and the return air passage are alternately stacked. Not connected to each other;

a PLC controller, an environment monitoring module and an external control panel are further disposed, the environment monitoring module is electrically connected to the PLC controller, and the external control panel is electrically connected to the PLC controller;

The fresh air blower and the return air blower are both electrically connected to the PLC controller;

The external control panel is a touch screen.

Further, the environmental monitoring module includes a temperature and humidity sensor, a CO ₂ sensor, a PM2.5 detector, and a VOC gas detector, and the temperature and humidity sensor, the CO ₂ sensor, the PM2.5 detector, and the VOC gas detector are respectively It is electrically connected to the PLC controller.

Further, the heat exchange core body is formed by laminating a plurality of layers of corrugated paper from bottom to top, and the orientation of each adjacent two layers of corrugated paper is placed at 90°.

Further, the surface of the heat exchange core (9) is fixed with a twill strip.

Further, a return air filter member is disposed, the return air filter member is located downstream of the indoor air return port and upstream of the return air passage, and the filter surface of the return air filter member and the gas flow The section has a predetermined angle.

Further, the predetermined angle is 40-50°.

Further, the fresh air filter and the return air filter both comprise a primary effect filter layer and a high efficiency filter layer, the primary effect filter layer is located before the high efficiency filter layer, and the primary effect filter layer is non-woven. A layer of cloth or fiberglass, the high-efficiency filter layer being a 3M electrostatic electret filter layer.

Further, the surfaces of the fresh air filter and the return air filter are fixed with a lifting cloth strip.

Further, the housing includes a first door panel, and the first door panel is located on a side where the fresh air filter member and the return air filter member are disposed, and one side of the first door panel is hinged to the housing through an inner hinge. The other side of the first door panel is provided with a buckle pull ring, and the housing is provided with a buckle hook matched with the buckle pull ring of the first door panel.

Further, the new fan that can be automatically controlled is a ceiling-type new fan, and a pair of corresponding hanging legs are respectively arranged at the left and right ends of the casing, and two sets of the hanging legs are arranged in each group.

Further, the first fan and the second fan are both centrifugal fans.

Further, the return air filter and the air inlet filter are both equipped with a screen clogging sensor, and the screen clogging sensor is electrically connected to the PLC controller.

Further, a clock device is disposed in the external control panel, and the clock device is electrically connected to the PLC controller.

Further, the external control panel is provided with a WIFI signal transceiver, the WIFI signal transceiver is electrically connected to the PLC controller, and the WIFI signal transceiver is wirelessly connected with an external user terminal.

Further, the external user terminal is a mobile phone or a tablet.

Further, a child lock device is further disposed in the external control panel, and the child lock device is electrically connected to the PLC controller.

Further, the casing is a three-layer structure composed of an outer layer, an intermediate layer and an inner layer, the intermediate layer being located between the outer layer and the inner layer, the outer layer and the inner layer All are spray-coated galvanized steel layers, and the intermediate layer is a PVC layer or an MBR layer.

Further, it further includes a power module that provides a power source, the power module being electrically connected to the PLC controller.

Further, the environmental monitoring module is one of the following three structures:

Structure 1. The temperature and humidity sensor, the CO ₂ sensor, the PM2.5 detector and the VOC gas detector are all integrated in the induction integrated box, and the induction integrated box is installed on the shell or the wall outside the fresh air purifier;

The structure 2, the temperature and humidity sensor, the CO ₂ sensor, the PM2.5 detector and the VOC gas detector are all integrated and installed in the induction integrated box, and the induction integrated box is installed on the wall of the outer periphery of the control panel;

Structure 3, temperature and humidity sensor, CO ₂ sensor, PM2.5 detector and VOC gas detector are installed in the casing of the fresh air purifier and close to the air inlet of the fresh air purifier.

The beneficial effects of the present invention are as follows:

1. The invention has a heat exchange core body, and the outdoor fresh air and the indoor return air pass through the heat exchange core after being filtered and purified, so that the outdoor fresh air recovers the energy of the indoor return air in the heat exchange core body, thereby achieving the ventilation change. The gas keeps the indoor temperature and humidity stable; when the fresh air purifier equipped with the heat exchange core is operated during the summer cooling period, the outdoor fresh air obtains the cooling amount from the indoor return air, so that the temperature is lowered and the indoor air is dried. To reduce the outdoor fresh air humidity; in the winter operation, the outdoor fresh air obtains heat from the indoor return air, so that the temperature rises and is humidified by the indoor return air; at the same time, a replaceable fresh air filter element is installed at the outdoor air inlet, which can effectively remove The various air pollutants in the outdoor air, the ceiling-type new fan can provide clean and oxygen-enriched air in the presence of outdoor air pollution, improve the applicability of the ceiling-type new fan; and set a replaceable return air in the indoor air return port. The filter element prevents the indoor polluted air from entering the heat exchange core body, keeps the interior of the ceiling type new fan clean, and prolongs the service life of the machine, and Protection simple;

2. In the present invention, the filtering surface of the fresh air filter element and the return air filter element has a predetermined angle with the gas flow cross section, and the predetermined angle is 40-50°, which not only ensures the maximum effective filtration area, but also does not affect the heat exchange core. The removal and maintenance of the body, the air purification rate is high, and the use is convenient;

3. The heat exchange core body used in the present invention is formed by stacking several layers of corrugated paper from bottom to top, and the orientation of each adjacent two layers of corrugated paper is placed at 90° to ensure that the fresh air tunnel and the return air passage are not in communication with each other. It will affect the quality of fresh air entering the room, and the purification effect is good; the heat exchange core adopts corrugated paper, and condensed water will not be generated during the work process, which will affect the operation of the machine, prolong the service life of the machine and save costs;

4. The casing of the present invention is a three-layer structure comprising an outer layer, an intermediate layer and an inner layer, which is lighter than the casing of other ceiling-type fresh air fans, and the intermediate interlayer is a PVC layer or an MBR layer, and has heat insulation. Sound insulation effect.

5. In the present invention, an environmental monitoring module such as a temperature and humidity sensor, a CO ₂ sensor, a PM2.5 detector, and a VOC gas detector is installed to monitor the air, and the operation data is automatically adjusted by monitoring the data to meet various polluted air. The need for purification, the use of new fans is good;

Sixth, the invention is provided with a filter clogging sensor, and an alarm is issued when the filter clogging affects the air purification, reminding to replace the filter screen, improving the air purification efficiency, and benefiting the health and safety of the human body;

7. The invention is provided with a child lock device to prevent the child from touching the external control panel at will, causing the new fan to be mishandled or even destroyed, and the safety is good, and the service life of the new fan is prolonged;

8. The invention also has a WIFI signal transceiver, and is wirelessly connected with an external user terminal, and the user can view the operation status and various parameters of the new fan at any time through the terminal device, and can also adjust the operation mode directly on the user terminal device.

DRAWINGS

Figure 1 is a plan view of the internal structure of the present invention;

2 is a schematic structural view of a heat exchange core of the present invention;

Figure 3 is a schematic view of the casing of the present invention;

Figure 4 is a schematic view showing the opening of the first door panel of the casing of the present invention;

Figure 5 is a schematic view of the control principle of the present invention;

The parts in the drawing are marked as follows:

Outdoor air inlet 1, outdoor air outlet 2, indoor air return 3, indoor air supply port 4, fresh air filter 5, air inlet fan 6, return air filter 7, return air fan 8, heat exchange core 9, return air The tunnel 92, the fresh air tunnel 91, the hanging foot 10, the environmental monitoring module 11, the temperature and humidity sensor 111, the CO ₂ sensor 112, the PM2.5 detector 113, the VOC gas detector 114, the external control panel 12, the WIFI signal transceiver 121, The child lock device 122, the PLC controller 13, the first door panel 14, the inner hinge 141, the buckle tab 142, the buckle hook 143, the power module 15, the screen jam sensor 16, and the predetermined angle α.

detailed description

The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings, in which the advantages and features of the invention can be more readily understood by those skilled in the art.

Embodiment: A new fan with automatic control function, as shown in FIG. 1-5, includes a casing, an outdoor air inlet 1, an outdoor air outlet 2, an indoor air return port 3, and an indoor air supply port 4, the outdoor The air outlet 2 and the outdoor air inlet 1 are respectively located at the left end of the casing, and the indoor air return port 3 and the indoor air supply port 4 are respectively located at the right end of the casing;

A new air passage and a return air passage are disposed in the housing, and a fresh air filter member 5 and an air inlet fan 6 are respectively disposed at two ends of the fresh air passage, and the fresh air filter member 5 is connected to the outdoor air inlet 1 The inlet air blower 6 is in communication with the indoor air supply port 4, and one end of the return air passage is provided with a return air blower 8, and the return air blower 8 is in communication with the outdoor air exhaust port 2, and the return air passage is The other end is in communication with the indoor air return port 3, the filter surface of the fresh air filter 5 has a predetermined angle α with the gas flow cross section;

A heat exchange core 9 is further disposed at an intersection of the fresh air passage and the return air passage, and the heat exchange core 9 includes a fresh air passage 91 and a return air passage 92. The air inlet of the fresh air tunnel is connected to the outdoor air inlet through a fresh air filter, and the air outlet of the new air passage is connected to the indoor air supply port through an air inlet fan, and the air inlet of the return air passage is connected with the indoor air return port, and the return air is The air outlet of the tunnel is connected to the outdoor air outlet through a return air fan, and the fresh air tunnel 91 and the return air passage 92 are alternately stacked from bottom to top by a plurality of ventilation members and a plurality of sealing members. The fresh air tunnel 91 and the return air passage 92 are not in communication with each other;

Further, a PLC controller 13 , an environment monitoring module 11 and an external control panel 12 are provided. The environment monitoring module 11 is electrically connected to the PLC controller 13 , and the external control panel 12 is electrically connected to the PLC controller 13 ;

The external control panel 12 is a touch screen.

The environmental monitoring module 11 includes a temperature and humidity sensor 111, a CO ₂ sensor 112, a PM2.5 detector 113, and a VOC gas detector 114, and the temperature and humidity sensor, the CO ₂ sensor, the PM2.5 detector, and the VOC gas detector They are electrically connected to the PLC controller, respectively.

Preferably, in the embodiment, the heat exchange core body is formed by laminating a plurality of layers of corrugated paper from bottom to top, and the orientation of each adjacent two layers of corrugated paper is placed at 90°.

A twill strip is fixed to the surface of the heat exchange core 9.

a return air filter member 7 is disposed, the return air filter member is located downstream of the indoor air return port and upstream of the return air passage, and the filter surface of the return air filter member and the gas flow cross section have predetermined Angle α.

The predetermined angle α is 40-50°.

The fresh air filter and the return air filter both comprise a primary filter layer and a high efficiency filter layer, and the primary filter layer is located before the high efficiency filter layer, and the primary filter layer is a non-woven layer or glass. The fiber layer, the high efficiency filter layer is a 3M electrostatic electret filter layer.

The surface of the fresh air filter and the return air filter is fixed with a lifting cloth strip.

The housing includes a first door panel 14 on a side where a fresh air filter member and a return air filter member are disposed, one side of the first door panel being hinged to the housing by an inner hinge 141, The other side of the first door panel is provided with a buckle pull ring 142, and the housing is provided with a buckle hook 143 matching the buckle pull ring of the first door panel.

Preferably, the housing is further provided with a second door panel (not shown), the second door panel is located on a side provided with an air inlet fan and a return air fan, and one side of the second door panel is The housing is hinged by an inner hinge, and the other side of the second door panel is provided with a buckle pull ring, and the housing is provided with a snap hook matching the buckle pull ring of the second door panel.

Preferably, in the embodiment, the lower side of the first door panel and the second door panel and the housing are hinged by an inner hinge, and the upper side of the first door panel and the second door panel are provided with a buckle tab The upper surface of the housing is provided with a snap hook that matches the snap tab of the first door panel and the second door panel.

In a specific implementation, the new fan with automatic control function is a rectangular parallelepiped casing, and the rectangular parallelepiped casing includes a top surface, a bottom surface opposite to the top surface, and a side surface connecting the top surface and the bottom surface, the side surface including the left side surface at the left end, located at a right side of the right end, a front side of the front side, and a rear side of the rear side, the outdoor air inlet and the outdoor air outlet are located on the left side, and the indoor air return and the indoor air supply opening are located on the right side. The first door panel constitutes a front side, and the second door panel constitutes a rear side.

The new fan with automatic control function is a ceiling type new fan, and a pair of corresponding hanging feet 10 are respectively arranged at the left and right ends of the casing, and each set of the hanging feet has two.

In a specific implementation, the two sets of the hanging feet are respectively located at the upper ends of the left side surface and the right side surface of the housing.

Both the return air filter 7 and the fresh air filter 5 are equipped with a screen clogging sensor 16, which is electrically connected to the PLC controller 13.

A clock device is disposed in the external control panel, and the clock device is electrically connected to the PLC controller 8.

The external control panel is provided with a WIFI signal transceiver 121. The WIFI signal transceiver is electrically connected to the PLC controller 13, and the WIFI signal transceiver is wirelessly connected with an external user terminal.

The external user terminal is a mobile phone or a tablet.

A child lock device 122 is further disposed in the external control panel, and the child lock device is electrically connected to the PLC controller 13.

The casing is a three-layer structure composed of an outer layer, an intermediate layer and an inner layer, the intermediate layer being located between the outer layer and the inner layer, and the outer layer and the inner layer are both sprayed A galvanized steel layer, the intermediate layer being a PVC (polyvinyl chloride) layer or an MBR (hollow fiber membrane) layer.

Also included is a power module that provides a power source that is electrically coupled to the PLC controller.

The environmental monitoring module is one of the following three structures:

Preferred in this embodiment is structure 3. The temperature and humidity sensor, the CO ₂ sensor, the PM2.5 detector and the VOC gas detector are all installed in the casing of the fresh air purifier and close to the air inlet of the fresh air purifier.

The working principle of the invention is as follows:

The invention sends the outdoor fresh air into the room after filtering, purifying and heat treatment, and at the same time, the indoor return air is filtered and purified and heat exchanged and discharged to the outside; the outdoor fresh air and the indoor return air are filtered and purified and passed through the heat exchange core. Body, outdoor fresh air recovers the energy of indoor return air in the heat exchange core body, thereby achieving the effect of ventilating and maintaining indoor temperature and humidity stability; when the fresh air purifier equipped with the heat exchange core body is running during the summer cooling period, The outdoor fresh air obtains the cold amount from the indoor return air, so that the temperature is lowered, and the indoor return air is dried, so that the outdoor fresh air humidity is lowered; in the winter operation, the outdoor fresh air obtains heat from the indoor return air, so that the temperature rises and is simultaneously Indoor return air humidification; at the same time, a replaceable fresh air filter is installed at the outdoor air inlet to effectively remove various pollutants in the outdoor air, so that the ceiling type new fan can provide clean and oxygen-rich in the case of outdoor air pollution. Air, improve the applicability of the ceiling-type new fan; set the replaceable return air filter at the indoor air return to avoid the room Air pollution into the heat exchange core, the inside of the ceiling type holding new fan clean and prolong the life of the machine, and simple maintenance.

In the invention, an environmental monitoring module such as a temperature and humidity sensor, a CO ₂ sensor, a PM2.5 detector and a VOC gas detector is installed to monitor the air, and the operation data is automatically adjusted by monitoring the data to satisfy people's purification of various polluted air. Demand, the use of new fans is good;

There is a filter plugging sensor, which will give an alarm when the filter is blocked and affect the air purification, reminding to replace the filter screen, improve the air purification efficiency, and is beneficial to people's health and safety;

It also has a WIFI signal transceiver, and is wirelessly connected with an external user terminal. The user can view the operation status and various parameters of the new fan at any time through the terminal device, and can also adjust the operation mode directly on the user terminal device.

The above is only the embodiment of the present invention, and thus does not limit the scope of the patent of the present invention. Any equivalent structural transformation made by using the specification and the drawings of the present invention, or directly or indirectly applied to other related technical fields, is the same. The scope of the invention is included in the scope of the patent protection of the present invention.

Claims

A new type of fan with automatic control function, characterized in that:

The utility model comprises a casing, an outdoor air inlet (1), an outdoor air outlet (2), an indoor air return port (3) and an indoor air supply port (4), the outdoor air outlet (2) and the outdoor air inlet (1) ) respectively located at the left end of the housing, the indoor air return opening (3) and the indoor air supply opening (4) are respectively located at the right end of the housing;

A fresh air passage and a return air passage are disposed in the housing, and a fresh air filter (5) and an air inlet fan (6) are respectively disposed at two ends of the fresh air passage, and the fresh air filter (5) and the outdoor air are respectively disposed The air inlet (1) is connected to communicate with the indoor air supply port (4), and one end of the return air passage is provided with a return air fan (8), and the return air fan (8) The other end of the return air passage is in communication with the indoor air return port (3), and the filtering surface of the fresh air filter member (5) and the gas flow cross section have predetermined clips. Angle (α);

A heat exchange core (9) is also included, the heat exchange core (9) is located at the intersection of the fresh air passage and the return air passage, and the heat exchange core (9) includes a fresh air tunnel (91) And a return air passage (92), the air inlet of the fresh air tunnel is connected to the outdoor air inlet through a fresh air filter, and the air outlet of the new air passage is connected to the indoor air supply port through an air inlet fan, and the air inlet of the return air passage The air outlet of the return air passage is connected to the outdoor air outlet through a return air blower, and the new air passage (91) and the return air passage (92) are provided by a plurality of ventilation members and a plurality of sealing members. The bottom view is alternately stacked at intervals, and the new air tunnel (91) and the return air passage (92) are not in communication with each other;

There is also a PLC controller (13), an environmental monitoring module (11) and an external control panel (12), the environmental monitoring module (11) is electrically connected to the PLC controller (13), and the external control panel ( 12) being electrically connected to the PLC controller (13);

The fresh air blower and the return air blower are both electrically connected to the PLC controller;

The external control panel (12) is a touch screen.
A new fan with automatic control function according to claim 1, characterized in that the environmental monitoring module (11) comprises a temperature and humidity sensor (111), a CO 2 sensor (112), and a PM2.5 detector ( 113) and a VOC gas detector (114), wherein the temperature and humidity sensor, the CO 2 sensor, the PM2.5 detector, and the VOC gas detector are electrically connected to the PLC controller, respectively.
A new air blower with automatic control function according to claim 1, characterized in that: a return air filter (7) is provided, and the return air filter is located downstream of the indoor air return port and located at the back Upstream of the wind tunnel, the filtering surface of the return air filter has a predetermined angle (α) with the gas flow cross section.
A new air blower having an automatic control function according to claim 1, wherein said predetermined angle (α) is 40-50°.
A new fan with automatic control function according to claim 1, characterized in that the return air filter (7) and the fresh air filter (5) are equipped with a filter clogging sensor (16), The screen clogging sensor is electrically coupled to the PLC controller (13).
A new fan with automatic control function according to claim 1, characterized in that: the external control panel is provided with a clock device, and the clock device is electrically connected to the PLC controller (13).
A new fan with automatic control function according to claim 1, wherein: the external control panel is provided with a WIFI signal transceiver (121), the WIFI signal transceiver and the PLC controller ( 13) Electrical connection, the WIFI signal transceiver is wirelessly connected to an external user terminal.
A new air blower with automatic control function according to claim 4, wherein the external user terminal is a mobile phone or a tablet computer.
A new air blower with automatic control function according to claim 1, wherein the external control panel is further provided with a child lock device (122), the child lock device and the PLC controller (13) ) Electrical connection.
A new air blower having an automatic control function according to claim 1, wherein said casing is a three-layer structure composed of an outer layer, an intermediate layer and an inner layer, said intermediate layer being located at said outer layer Between the inner layer and the inner layer, the outer layer and the inner layer are both spray-coated galvanized steel layers, and the intermediate layer is a PVC layer or an MBR layer.