Fresh air machine

Abstract

The application relates to the air conditioning technical field, and discloses a fresh air machine. The fresh air machine comprises a shell which defines a fresh air duct, an internal circulation duct and a shared duct. One end of the fresh air duct is in communication with the outside, the other end of the fresh air duct is in communication with one end of the shared duct, one end of the internal circulation duct is in communication with the inside, the other end of the internal circulation duct is in communication with one end of the shared duct, and the other end of the shared duct is in communication with the inside. The fresh air duct and the internal circulation duct share the shared duct, and are both in communication with the inside through the other end of the shared duct, so that the fresh air duct and the internal circulation duct intersect at the shared duct instead of intersecting each other in the related art, thereby reducing the volume of the fresh air machine by arranging the shared duct.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, specifically to a fresh air ventilator. Background Technology

[0002] Currently, fresh air systems introduce outdoor air into the room to improve indoor air quality. However, when outdoor air quality is poor, introducing outdoor air can actually pollute the indoor air.

[0003] Therefore, an indoor air purification system is disclosed in the related technology. The indoor air purification system includes an indoor air purification system and a fresh air purification system; the fresh air purification system includes a fresh air heat exchange unit and an indoor heat exchange unit; the fresh air heat exchange unit includes a fresh air inlet, a micro positive pressure fan that introduces fresh air into the system, a fresh air PCB control module, a heat exchange core that exchanges heat with the fresh air, and a fresh air outlet; the indoor heat exchange unit includes an indoor air inlet, an indoor air filter element installed at the indoor air inlet, a heat exchange core shared with the fresh air heat exchange unit, and an outlet fan that discharges the indoor air that has passed through the heat exchange core to the indoor air outlet.

[0004] In the process of implementing the embodiments of this disclosure, at least the following problems were found in the related art:

[0005] The fresh air heat exchange unit and the indoor heat exchange unit are arranged in a cross pattern at the heat exchange core, resulting in a large volume of the entire indoor purification system.

[0006] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Utility Model Content

[0007] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0008] This disclosure provides a fresh air system to address the issue of large volume occupancy in indoor air purification systems in related technologies.

[0009] According to a first aspect of the present invention, a fresh air ventilator is provided, comprising: a housing defining a fresh air duct, an internal circulation duct, and a common duct, wherein one end of the fresh air duct is connected to the outside and the other end is connected to one end of the common duct, one end of the internal circulation duct is connected to the interior and the other end is connected to one end of the common duct, and the other end of the common duct is connected to the interior.

[0010] Optionally, the housing includes: a first housing segment defining a fresh air duct and a common air duct, wherein the fresh air duct and the common air duct are arranged sequentially along the length of the first housing segment.

[0011] Optionally, the housing further includes a second housing section defining an internal circulation duct, the second housing section being located outside the first housing section and on one side of the airflow direction within the common duct.

[0012] Optionally, the fresh air unit further includes: an air damper, movably disposed between the other end of the internal circulation duct and one end of the common duct to control whether the internal circulation duct and the common duct are connected; or, movably disposed between the other end of the fresh air duct and one end of the common duct to control whether the fresh air duct and the common duct are connected.

[0013] Optionally, the fresh air unit further includes: a first fan, located in the internal circulation duct, for driving indoor air to flow through one end of the internal circulation duct to the common duct.

[0014] Optionally, the fresh air unit further includes: a second fan, located in the common air duct, for driving the air in the common air duct to flow from one end of the common air duct to the other end, or from the other end of the common air duct to the first end.

[0015] Optionally, the fresh air unit may also include: a heat exchanger located within a common air duct; and / or a filter located within a common air duct.

[0016] Optionally, the heat exchanger, the second fan, and the filter are arranged sequentially along the direction from one end to the other end of the common air duct.

[0017] Optionally, the fresh air unit also includes a control board, which is connected to both the first and second fans. When the fresh air duct is connected to the common air duct, the control board turns on the second fan and turns off the first fan; when the internal circulation duct is connected to the common air duct, the control board turns on both the first and second fans.

[0018] Optionally, the fresh air unit further includes a baffle, disposed at one end of the fresh air duct and movably connected to the housing, to open or close the one end of the fresh air duct.

[0019] The fresh air system provided in this disclosure can achieve the following technical effects:

[0020] The fresh air duct and the internal circulation duct share a common duct, and the other end of the common duct is connected to the indoor environment. This means that air in the fresh air duct can enter the common duct and then enter the indoor environment to achieve the fresh air function, or air in the internal circulation duct can enter the common duct and then enter the indoor environment to achieve the internal circulation of indoor air.

[0021] The fresh air duct and the internal circulation duct share a common duct, and both are connected to the indoor environment through the other end of the common duct. This allows the fresh air duct and the internal circulation duct to intersect at the common duct, rather than crossing each other as in related technologies. This reduces the size of the fresh air unit by setting up a common duct.

[0022] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0023] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein:

[0024] Figure 1 This is a schematic diagram of the structure of a fresh air unit provided in an embodiment of this disclosure;

[0025] Figure 2 This is a schematic diagram of another fresh air unit provided in an embodiment of this disclosure;

[0026] Figure 3 yes Figure 2 Sectional view along the middle AA direction;

[0027] Figure 4 This is a schematic diagram of another fresh air unit provided in an embodiment of this disclosure.

[0028] Figure label:

[0029] 100: Fresh air unit; 101: First shell section; 102: Second shell section; 103: Connecting shell section;

[0030] 20: Fresh air duct; 201: One end of the fresh air duct; 202: The other end of the fresh air duct;

[0031] 30: Shared air duct; 301: One end of the shared air duct; 302: The other end of the shared air duct;

[0032] 40: Internal circulation air duct; 401: One end of the internal circulation air duct; 402: The other end of the internal circulation air duct;

[0033] 501: Baffle; 502: Air damper;

[0034] 601: Heat exchange component; 602: Filter component; 603: First fan; 604: Second fan;

[0035] 701: Control panel; 702: Cover plate. Detailed Implementation

[0036] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0037] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0038] In this disclosure, the terms "upper," "lower," "inner," "middle," "outer," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for better description of the embodiments of this disclosure and their implementations, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to require them to be constructed and operated in a specific orientation. Furthermore, some of the aforementioned terms may be used to indicate other meanings besides orientation or positional relationship; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in the embodiments of this disclosure according to the specific circumstances.

[0039] Furthermore, the terms "set up," "connect," and "fix" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0040] Unless otherwise stated, the term "multiple" means two or more.

[0041] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0042] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0043] It should be noted that, unless otherwise specified, the embodiments and features described in the present disclosure can be combined with each other.

[0044] Combination Figure 1-4 As shown, this embodiment of the present disclosure provides a fresh air unit 100, including a housing.

[0045] The casing defines a fresh air duct 20, an internal circulation duct 40, and a common duct 30. One end 201 of the fresh air duct is connected to the outside, and the other end is connected to one end 301 of the common duct. One end 401 of the internal circulation duct is connected to the inside, and the other end is connected to one end 301 of the common duct. The other end 302 of the common duct is connected to the inside.

[0046] Outdoor air can also flow into fresh air duct 20 through one end 201 of the fresh air duct, and into one end 301 of the common air duct through the other end 202 of the fresh air duct, and then into the room through the other end 302 of the common air duct to achieve the fresh air function. Alternatively, indoor air can also flow into the common air duct 30 through the other end 302 of the common air duct, and into the other end 202 of the fresh air duct through the other end 301 of the common air duct, and then out to the outside through the other end 201 of the fresh air duct.

[0047] Indoor air can flow into the internal circulation duct 40 through one end 401 of the internal circulation duct, into the common duct 301 through the other end 402 of the internal circulation duct, and then into the room through the other end 302 of the common duct, thus achieving internal air circulation. Alternatively, indoor air can flow into the common duct 30 through the other end 302 of the common duct, into the common duct 301 through the other end 402 of the internal circulation duct, and then into the room through the other end 301 of the internal circulation common duct.

[0048] like Figure 3 As shown, the other end 402 of the internal circulation duct and the other end 202 of the fresh air duct are both connected to the common duct 30, and are connected to the indoor environment through the other end 302 of the common duct. That is, the fresh air duct 20 and the internal circulation duct 40 intersect at the common duct 30, instead of crossing the fresh air duct 20 and the internal circulation duct 40 as in related technologies. Thus, the volume of the fresh air unit 100 is reduced by setting the common duct 30.

[0049] Optionally, the housing includes a first housing segment 101, which defines a fresh air duct 20 and a common air duct, which are arranged sequentially along the length of the first housing segment 101.

[0050] The fresh air duct 20 and the common air duct are arranged sequentially along the length of the first shell section 101. On the one hand, the first shell section 101 can define both the fresh air duct 20 and the common air duct 30, thereby simplifying the structure of the fresh air unit 100. On the other hand, since both the fresh air duct 20 and the common air duct are defined by the first shell section 101, the air resistance of the air flowing in the fresh air duct 20 and the common air duct 30 can be reduced.

[0051] The first shell section 101 is straight, so that the airflow direction in the fresh air duct 20 is the same as the airflow direction in the common air duct 30, allowing air to flow smoothly between the fresh air duct 20 and the common air duct 30.

[0052] It is understandable that the first shell segment 101 can also be curved.

[0053] Optionally, such as Figure 1 As shown, the housing also includes a second housing section 102, which defines an internal circulation duct 40. The second housing section 102 is located outside the first housing section 101 and on one side of the airflow direction within the common duct 30.

[0054] A first through hole is provided on the wall, and the first shell section 101 passes through the first through hole, reducing the indoor space occupied by the fresh air unit 100. Among them, one end 201 of the fresh air duct is located outdoors, so that outdoor air can be connected to one end 201 of the fresh air duct, and the other end 302 of the common air duct is located indoors, so that indoor air can be connected to the other end 302 of the common air duct.

[0055] The second shell section 102 is located outside the first shell section 101 and on one side of the air flow direction within the common air duct 30. This not only enables indoor air circulation by setting the second shell section 102, but also makes the entire fresh air unit 100 have a compact structure.

[0056] A second through hole is also provided in the wall, through which the second shell section 102 passes, meaning that the second shell section 102 is at least partially located within the wall, in order to reduce the indoor space occupied by the second shell section 102. The first through hole and the second through hole can be two independent through holes, i.e., they are not connected, or the first through hole and the second through hole can be connected, and the two can be combined into a single hole.

[0057] The second shell section 102 can also be entirely located indoors, in which case there is no need to install a second through hole on the wall.

[0058] The cross-sections of the first shell segment 101 and the second shell segment 102 can be annular. In this case, the inner and outer diameters of the first shell segment 101 and the second shell segment 102 can be set according to actual needs. For example, the outer diameter can be set to 160mm. Alternatively, the cross-sections of the first shell segment 101 and the second shell segment 102 can be any other shape.

[0059] One end 401 of the internal circulation duct and the other end 302 of the shared duct are both connected to the indoor environment and are located indoors, and are on the same plane, which enhances the aesthetics of the fresh air unit 100.

[0060] The fresh air unit 100 also includes a cover plate 702, which is located on the front side of the other end 302 of the common air duct. That is, along the air outlet direction, the other end 302 of the common air duct and the cover plate 702 are arranged in sequence to improve the aesthetics of the fresh air unit 100.

[0061] Optionally, the fresh air unit 100 also includes an air damper 502, such as Figure 3 As shown, the damper 502 is movably disposed between the other end of the internal circulation duct 40 and one end of the common duct 30 to control whether the internal circulation duct 40 and the common duct 30 are connected, or the damper 502 is movably disposed between the other end of the fresh air duct 20 and one end of the common duct 30 to control whether the fresh air duct 20 and the common duct 30 are connected.

[0062] When the damper 502 is movably positioned between the other end 402 of the internal circulation duct and one end 301 of the common duct, the movement of the damper 502 relative to the housing controls whether the internal circulation duct 40 and the common duct 30 are connected. When the damper 502 opens the connection between the other end 402 of the internal circulation duct and one end 301 of the common duct, the internal circulation duct 40 and the common duct 30 are connected, allowing indoor air to flow into the internal circulation duct 40 through one end 401, then into one end 301 of the common duct, and finally into the room through the other end 302 of the common duct, thus achieving internal air circulation. When the damper 502 closes the connection between the other end 402 of the internal circulation duct and one end 301 of the common duct, the internal circulation duct 40 and the common duct 30 are not connected. Due to the obstruction of the damper 502, air in the fresh air duct 20 cannot enter the internal circulation duct 40, thus preventing chaotic airflow.

[0063] When the damper 502 is movably positioned between the other end 202 of the fresh air duct and one end 301 of the common air duct, the movement of the damper 502 relative to the housing controls whether the fresh air duct 20 and the common air duct 30 are connected. When the damper 502 opens the connection between the other end 202 of the fresh air duct and one end 301 of the common air duct, the fresh air duct 20 and the common air duct 30 are connected, allowing outdoor air to flow into the fresh air duct 20 through one end 201, then into one end 301 of the common air duct, and finally into the room through the other end 302 of the common air duct, thus achieving the fresh air function. When the damper 502 closes the connection between the other end 202 of the fresh air duct and one end 301 of the common air duct, the fresh air duct 20 and the common air duct 30 are not connected. Due to the obstruction of the damper 502, air in the internal circulation duct 40 cannot enter the fresh air duct 20, thus preventing chaotic airflow.

[0064] Optionally, such as Figure 3 As shown, the fresh air unit 100 also includes a first fan 603, which is located in the internal circulation duct 40 and is used to drive indoor air to flow through one end of the internal circulation duct 40 to the common duct 30.

[0065] A first fan 603 is installed to drive the air flow in the internal circulation duct 40 to the common duct 30, thereby realizing the internal circulation of indoor air.

[0066] The axis of the first fan 603 coincides with the axis of the internal circulation duct 40 at its location.

[0067] The housing also includes a connecting shell segment 103, which connects the first shell segment 101 and the second shell segment 102. There is a bend at the connection between the connecting shell segment 103 and the first shell segment 101, and there is a bend at the connection between the connecting shell segment 103 and the second shell segment 102.

[0068] Optionally, the fresh air unit 100 further includes a second fan 604, which is disposed in the common air duct 30 and is used to drive the air in the common air duct 30 to flow from one end of the common air duct 30 to the other end, or from the other end 302 of the common air duct to the first end.

[0069] The axis of the second fan 604 coincides with the axis of the common air duct 30, so as to drive air to flow in the common air duct 30 along the length of the common air duct 30.

[0070] Optionally, the fresh air unit 100 also includes a heat exchanger 601 and / or a filter 602.

[0071] The heat exchanger 601 is located within the common air duct 30. The filter 602 is located within the common air duct 30.

[0072] The heat exchanger 601 can exchange heat with the air flowing through it, realizing the recycling of heat. The heat exchanger 601 can be a ceramic heat exchange core, a polymer membrane heat exchange core, a heat exchanger, etc., and can store heat. For example, when the fresh air duct 20 is connected to the common air duct 30 and the outdoor air temperature is high, the outdoor air flows through the heat exchanger 601, and the heat exchanger 601 exchanges heat with the outdoor air and stores heat. When internal circulation is performed, the indoor air flows through the heat exchanger 601 and can exchange heat with the heat exchanger 601, absorbing the heat from the heat exchanger 601 and increasing the indoor air temperature. For example, when air in the internal circulation duct 40 passes through the heat exchanger 601, the heat exchanger 601 can store heat. So when the outdoor air temperature is low, if the fresh air function is turned on, the colder outdoor air can exchange heat with the heat exchanger 601 when it passes through the heat exchanger 601, raising the outdoor air temperature and preventing the indoor air temperature from being too low. Thus, the fresh air function can be turned on even when the weather is cold.

[0073] The filter element 602 can filter the air flowing through it, thereby improving the air quality.

[0074] Optionally, along the direction from one end to the other end of the common air duct 30, the heat exchanger 601, the second fan 604, and the filter 602 are arranged in sequence.

[0075] In this way, the air entering the common air duct 30 through the internal circulation air duct 40 or the fresh air duct 20 passes through the heat exchanger 601, the second fan 604, and the filter 602 in sequence. Driven by the second fan 604, the air can flow smoothly through the heat exchanger 601 and the filter 602. Moreover, the filter 602 is relatively close to the other end 302 of the common air duct. Thus, the air entering the common air duct 30 from the internal circulation air duct 40 or the fresh air duct 20 passes through the filter 602 only when it is close to the other end 302 of the common air duct, thereby ensuring the quality of the air entering the room and preventing the air from being polluted again after passing through the filter 602.

[0076] Optionally, the fresh air unit 100 also includes a control board 701, which is connected to both the first fan 603 and the second fan 604. When the fresh air duct 20 is connected to the common air duct 30, the control board 701 controls the second fan 604 to turn on and controls the first fan 603 to turn off. When the internal circulation duct 40 is connected to the common air duct 30, the control board 701 controls both the first fan 603 and the second fan 604 to turn on.

[0077] With the fresh air duct 20 connected to the shared air duct 30, the second fan 604 is turned on. Driven by the second fan 604, outdoor air enters the shared air duct 30 through the fresh air duct 20 and then enters the room; or, indoor air enters the fresh air duct 20 through the shared air duct 30 and then enters the outside. At this time, the first fan 603 is turned off, and there is no airflow in the internal circulation duct 40.

[0078] When the internal circulation duct 40 is connected to the common duct 30, the first fan 603 and the second fan 604 are both turned on. The first fan 603 drives indoor air to enter the internal circulation duct 40 through one end 401 of the internal circulation duct and drives the air to flow to the other end 402 of the internal circulation duct, then enters the connecting shell section 103, and enters the common duct 30 through the connecting shell section 103. Driven by the second fan 604, the air is discharged into the room through the other end 302 of the common duct.

[0079] Optionally, such as Figure 3 As shown, the fresh air unit 100 also includes a baffle 501, which is disposed at one end of the fresh air duct 20 and is movably connected to the housing to open or close the one end of the fresh air duct 20.

[0080] The baffle 501 is used to control the opening and closing of one end 201 of the fresh air duct.

[0081] The fresh air unit 100 also includes a first driving device and a second driving device. The first driving device is driven to connect to the damper 502 and is used to drive the damper 502 to move relative to the housing. The second driving device is driven to connect to the baffle 501 and is used to drive the baffle 501 to move relative to one end 201 of the fresh air duct to open or close one end 201 of the fresh air duct.

[0082] The control board 701 is connected to both the first drive device and the second drive device. Taking the damper 502 located at the other end 402 of the internal circulation duct and one end 301 of the common duct as an example, when the fresh air duct 20 is connected to the common duct 30, the control board 701 controls the first drive device to move the damper 502, and the damper 502 closes the connection between the internal circulation duct 40 and the common duct 30. The second drive device drives the baffle 501 to open one end 201 of the fresh air duct, so that outdoor air can enter the fresh air duct 20 through one end 201 of the fresh air duct or indoor air can flow into the outside from one end 201 of the fresh air duct. When the internal circulation duct 40 is connected to the common duct 30, the control board 701 controls the first drive device to move the damper 502. The damper 502 opens the connection between the internal circulation duct 40 and the common duct 30, so that indoor air enters the common duct 30 through the internal circulation duct 40 and is discharged into the room through the other end 302 of the common duct. Meanwhile, the second drive device drives the baffle 501 to close one end 201 of the fresh air duct. The first fan 603 and the second fan 604 are both turned on. The first fan 603 drives indoor air to flow into the internal circulation duct 40 and then into the common duct 30. The second fan 604 drives the air to be discharged into the room through the other end 302 of the common duct. When the air passes through the filter 602, the air is purified.

[0083] The foregoing description and accompanying drawings fully illustrate embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included or substituted for parts and features of other embodiments. Embodiments of the present disclosure are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from its scope. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A fresh air machine characterized by, The new air machine comprises: a shell defining a fresh air duct, an internal circulation air duct and a common air duct, wherein one end of the fresh air duct is in communication with the outdoor, the other end of the fresh air duct is in communication with one end of the common air duct, one end of the internal circulation air duct is in communication with the indoor, the other end of the internal circulation air duct is in communication with one end of the common air duct, and the other end of the common air duct is in communication with the indoor.

2. The fresh air machine of claim 1, wherein, The shell comprises: a first shell section defining the fresh air duct and the common air duct, and the fresh air duct and the common air duct are sequentially arranged along the length direction of the first shell section.

3. The fresh air machine of claim 2, wherein, The shell further comprises: a second shell section defining the internal circulation air duct, and the second shell section is arranged outside the first shell section and located at one side of the common air duct in the air flow direction.

4. The fresh air machine of claim 1, wherein, Further comprising: a damper movably arranged between the other end of the internal circulation air duct and the one end of the common air duct to control whether the internal circulation air duct and the common air duct are in communication, or movably arranged between the other end of the fresh air duct and the one end of the common air duct to control whether the fresh air duct and the common air duct are in communication.

5. The fresh air machine of any one of claims 1 to 4, wherein, Further comprising: a first fan arranged in the internal circulation air duct for driving the indoor air to flow from the one end of the internal circulation air duct to the common air duct.

6. The fresh air machine of claim 5, wherein, Further comprising: a second fan arranged in the common air duct for driving the air in the common air duct to flow from the one end of the common air duct to the other end of the common air duct, or to flow from the other end of the common air duct to the one end of the common air duct.

7. The fresh air machine of claim 6, wherein, Further comprising: a heat exchange member arranged in the common air duct; and / or a filter member arranged in the common air duct.

8. The new air machine according to claim 7, wherein the heat exchange member, the second fan and the filter member are sequentially arranged along the direction from the one end of the common air duct to the other end of the common air duct.

9. The fresh air machine of claim 6, wherein, Further comprising: a control panel connected with the first fan and the second fan, and in the case that the fresh air duct and the common air duct are in communication, the control panel controls the second fan to be turned on and the first fan to be turned off, and in the case that the internal circulation air duct and the common air duct are in communication, the control panel controls the first fan and the second fan to be turned on.

10. The fresh air machine of any one of claims 1 to 4, wherein, Further comprising: a baffle arranged at the one end of the fresh air duct and movably connected with the shell to open or close the one end of the fresh air duct.

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