Air duct assembly, indoor unit and heating and ventilation system

Abstract

The utility model discloses an air duct assembly, an indoor unit and a heating and ventilation system, the indoor unit comprises a draught fan, the air duct assembly comprises a first shell and a second shell, and the first shell and the second shell are matched to define a diffusion cavity and a draught fan cavity which communicate with each other and an air suction opening communicating with the draught fan cavity; the second shell comprises a shell main body and a drainage plate, the shell main body is provided with a backflow channel, the backflow channel comprises a backflow inlet and a backflow outlet, the backflow inlet is communicated with the diffusion cavity, and the backflow outlet is communicated with the fan cavity; the drainage plate is connected to the shell body and located on one side of the air suction opening, and an uneven part is arranged at the end, away from the backflow outlet, of the drainage plate. The air conditioner indoor unit can reduce flow vortex noise and improve the operation tone quality when the indoor unit is used, so that the user experience is improved.

Description

Technical Field

[0001] The present application relates to the technical field of air conditioning, and in particular to an air duct assembly, an indoor unit and a heating and ventilation system. Background Art

[0002] In the related art, the indoor unit of the HVAC system usually has a return channel in the air duct to reintroduce the airflow at the outlet side of the fan into the inlet side of the fan for pressurization. However, in this process, due to the gradient of upstream and downstream pressures in the return channel, a strong flow vortex appears at the tail of the return channel, resulting in a large noise generated by the duct machine, affecting the user experience. Utility Model Content

[0003] The embodiments of the present application provide an air duct assembly, an indoor unit, and a HVAC system, which can help reduce flow vortex noise, improve the operating sound quality of the indoor unit when in use, and thus enhance user experience.

[0004] In a first aspect, an embodiment of the present application provides an air duct assembly, which is applied to an indoor unit, wherein the indoor unit includes a first shell and a second shell, wherein the first shell cooperates with the second shell to define a pressure diffuser cavity and a fan cavity that are connected, and an air suction port connected to the fan cavity, wherein the second shell includes a shell body and a guide plate, wherein the shell body is provided with a return channel, wherein the return channel includes a return inlet and a return outlet, wherein the return inlet is connected to the pressure diffuser cavity, and the return outlet is connected to the fan cavity;

[0005] The guide plate is connected to the shell body and is located at one side of the air inlet. An uneven portion is provided at the end of the guide plate away from the return outlet.

[0006] In some of the embodiments, the uneven portion includes a tooth-like structure and / or a wave-like structure.

[0007] In some embodiments, when the uneven portion includes a toothed structure, the toothed structure includes a plurality of saw teeth sequentially arranged along the axial direction of the fan chamber, and the tooth roots of the plurality of saw teeth are connected to each other.

[0008] In some embodiments, when the uneven portion includes a toothed structure, the toothed structure includes a plurality of saw teeth sequentially arranged along the axial direction of the fan chamber, and the tooth roots of the plurality of saw teeth are spaced apart.

[0009] In some of the embodiments, in the axial direction of the fan cavity, the spacing distance between adjacent saw teeth located in the middle is smaller than the spacing distance between adjacent saw teeth located on both sides.

[0010] In some embodiments, the end surface of the saw teeth away from the reflux outlet is arranged in a plane;

[0011] And / or, the plurality of saw teeth have the same shape, and the width of the saw teeth gradually decreases in the direction in which the guide plate moves away from the reflux outlet.

[0012] In some embodiments, the guide plate is arranged at an angle, and the distance between the guide plate and the air suction port gradually increases in a direction away from the return outlet;

[0013] And / or, the second shell further includes a grille, which is detachably connected to the guide plate and covers the air inlet.

[0014] In some embodiments, the shell body includes a volute tongue and a lower shell of the pressure diffuser chamber connected to each other, and the volute tongue and the lower shell of the pressure diffuser chamber define the bottom surface of the pressure diffuser chamber, the side of the volute tongue facing away from the fan chamber cooperates with the lower shell of the pressure diffuser chamber to form the return channel and the return outlet, and the guide plate is connected to the lower shell of the pressure diffuser chamber;

[0015] The reflux inlet of the reflux channel is opened on the bottom surface of the diffuser chamber and is located between the volute tongue and the lower shell of the diffuser chamber or located on the lower shell of the diffuser chamber.

[0016] In some embodiments, the lower shell of the pressure diffuser cavity includes a shell body and a guide plate, and the shell body is connected to the volute tongue and cooperates to define the cavity bottom surface of the pressure diffuser cavity;

[0017] The guide plate is detachably connected to the shell body and is located on the side of the shell body away from the diffusion chamber. The side of the volute tongue facing away from the fan chamber cooperates with the guide plate to form the return channel and the return outlet. The guide plate is connected to one end of the guide plate away from the shell body.

[0018] In some of the embodiments, the guide plate and the flow guide plate are an integral structure.

[0019] In some embodiments, the outer wall surface of the volute tongue includes a guide surface and a pressure diffuser surface, the guide surface is configured to guide the airflow in the fan cavity to flow into the pressure diffuser cavity, the guide surface extends from the side of the volute tongue toward the fan cavity to the pressure diffuser cavity, the pressure diffuser surface is connected between the guide surface and the top surface of the lower shell of the pressure diffuser cavity, and the pressure diffuser surface and the top surface of the lower shell of the pressure diffuser cavity constitute the cavity bottom surface of the pressure diffuser cavity;

[0020] The top surface of the lower shell of the pressure diffuser chamber is provided with the reflux inlet.

[0021] In some embodiments, the width of the reflux channel remains constant or gradually expands from the reflux inlet toward the reflux outlet.

[0022] In a second aspect, an embodiment of the present application provides an indoor unit, which includes a fan and an air duct assembly as described above, and the fan is accommodated in the fan cavity.

[0023] In a third aspect, an embodiment of the present application provides a HVAC system, including an outdoor unit and an indoor unit as described above, wherein the indoor unit and the outdoor unit form a refrigerant cycle.

[0024] Based on the air duct assembly, indoor unit and HVAC system of the embodiment of the present application, a guide plate is provided to connect with the shell body having a return channel, and the guide plate is located on one side of the air inlet. In this way, the guide plate can guide the airflow flowing through the return channel, so that the airflow is more uniform and smooth and is directed to the fan in the fan cavity, reducing the influence of the airflow in the return channel on the fan in the fan cavity, so as to improve the working efficiency of the fan. In addition, an uneven portion is provided at the end of the guide plate away from the return outlet, so that the uneven portion breaks up the flow vortex at the return outlet of the return channel, reducing the number of flow vortices contained in the airflow, thereby weakening the strength of the flow vortex, which is more conducive to the operation of the fan in the fan cavity, and sending a more uniform and smooth airflow into the fan cavity, thereby improving the working efficiency of the indoor unit and reducing the aerodynamic noise during the operation of the indoor unit, so as to enhance the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0026] Figure 1 This is a structural schematic diagram of an indoor unit according to an embodiment of the present application;

[0027] Figure 2 for Figure 1 Schematic diagram of the exploded structure of the indoor unit shown;

[0028] Figure 3 This is a structural diagram of the indoor unit of this application from another perspective;

[0029] Figure 4 for Figure 3 A cross-sectional view at AA is shown;

[0030] Figure 5 for Figure 3 A cross-sectional view at BB is shown;

[0031] Figure 6 for Figure 5 A partial enlarged view of the middle A;

[0032] Figure 7 This is a schematic diagram of the structure of the indoor unit of the present application after the first housing and the fan are disassembled;

[0033] Figure 8 for Figure 7 A partial enlarged view of point B in the middle;

[0034] Fig. 9 This is a schematic diagram of the structure of the volute, shell body and water tray of the indoor unit of this application;

[0035] Fig.10 This is a schematic diagram of the structure of the guide plate and drainage plate of the indoor unit of this application.

[0036] Description of Figure Numbers:

[0037] 1. Indoor unit; 10. Air duct assembly; 11. Fan cavity; 12. Pressure diffuser cavity; 13. Heat exchange cavity; 14. Air inlet; 15. Air outlet; 20. First shell; 21. Upper shell of fan cavity; 22. Upper shell of pressure diffuser cavity; 23. Upper shell of heat exchange cavity; 30. Second shell; 31. Return channel; 311. Reinforcement rib; 3111. Hook; 32. Return inlet; 33. Return outlet; 30A. Shell body; 40. volute tongue; 41. guide surface; 42. diffusion surface; 50. lower shell of the diffusion chamber; 51. shell body; 52. guide plate; 521. connection part; 522. guide part; 52a. buckle hole; 60. water receiving tray; 30B. guide plate; 30b. uneven part; 70. side panel; 80. insulation layer; 91. fan; 91a. air inlet side; 92. heat exchanger; 93. electric control box assembly; 98. grille.

[0038] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0039] In order to make the objectives, technical solutions and advantages of the present application clearer, the following part will further describe the embodiments of the present application in detail in conjunction with the accompanying drawings.

[0040] When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are only examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0041] In the description of the present application, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances. In addition, in the description of the present application, unless otherwise specified, "multiple" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0043] One aspect of the present application proposes a HVAC system. In the embodiment of the present application, the HVAC system includes but is not limited to equipment such as air conditioners, multi-split units, and heat pumps, and can be used in large-scale places such as shopping malls and office buildings. Among them, the HVAC system may include an indoor unit 1, an outdoor unit, and a connecting pipe. The indoor unit 1 is connected to the outdoor unit through a connecting pipe so that the indoor unit 1 and the outdoor unit form a refrigerant cycle. In some actual use scenarios, the indoor unit 1 of the present application can be installed indoors, the outdoor unit is responsible for cooling or heating, and transports the refrigerant through the connecting pipe. The refrigerant exchanges heat with the indoor air and the outdoor air respectively, and the indoor unit 1 is responsible for transporting cold air or hot air to the room to achieve the effect of cooling or heating.

[0044] Reference Figures 1 to 3 The indoor unit 1 may include but is not limited to a duct unit, a wall-mounted air conditioner indoor unit, a vertical air conditioner indoor unit, and other structural forms. The duct unit is usually installed on the ceiling using a suspended ceiling and can be hidden in the ceiling, so that the duct unit has a better hiding effect and is more beautiful than other structural forms of the indoor unit 1. In addition, the duct unit adopts a decentralized air outlet, and the air outlet effect is more comfortable. The indoor unit includes an air duct assembly 10, a fan 91, a heat exchanger 92, and an electric control box assembly 93.

[0045] The air duct assembly 10 is used to construct an air duct of the indoor unit 1 for air flow. Figure 2 and Figure 4Specifically, the air duct assembly 10 includes a first shell 20 and a second shell 30, wherein the first shell 20 and the second shell 30 cooperate to define a connected pressure diffuser chamber 12, a fan chamber 11 and a heat exchange chamber 13, and the first shell 20 and the second shell 30 also form an air inlet 14 connected to the fan chamber 11 and an air outlet 15 connected to the heat exchange chamber 13. Among them, the fan chamber 11 is configured to accommodate a fan 91. The pressure diffuser chamber 12 is used to receive the airflow blown from the fan chamber 11 and diffuse it to increase the pressure and flow of the airflow to improve the cooling or heating effect. The heat exchange chamber 13 is configured to accommodate a heat exchanger 92. In this way, the external airflow can flow in from the air inlet 14 under the action of the fan 91, and flow through the fan chamber 11, the pressure diffuser chamber 12 and the heat exchange chamber 13 in turn, so that after heat exchange through the heat exchanger 92 in the heat exchange chamber 13, the external airflow is heated or cooled and then flows out from the air outlet 15.

[0046] The first shell 20 and the second shell 30 can be alloys such as aluminum or steel or metal materials or hard plastic materials to meet the requirements of structural strength and long service life. Of course, the first shell 20 and the second shell 30 can also be made of plastic materials to meet the requirements of light weight, etc., and this application is not limited to this. Of course, it is also possible that one of the first shell 20 and the second shell 30 is made of alloy or metal material, and the other is made of plastic material. Further, the air duct assembly 10 also includes two side panels 70, which can be connected to the first shell 20 and the second shell 30 by snap-fit ​​or screw connection to achieve the fixation of the first shell 20 and the second shell 30, and the two side panels 70 are arranged oppositely. In this way, the first shell 20, the second shell 30 and the two side panels 70 are used to cooperate to construct the outline of the entire air duct assembly 10. And the air inlet 14 can be formed by the first shell 20, the second shell 30 and the side panels 70, and the air outlet 15 can be opened on the first shell 20.

[0047] It should be noted that the first shell 20, the second shell 30 and the side panel 70 can act as a shell, so there is no need to set up other structures such as additional shells, so as to reduce the number of structures of the air duct assembly 10 and reduce the volume of the air duct assembly 10, so as to achieve miniaturization of the indoor unit 1, so as to adapt to more use environments with compact installation space. Of course, in other embodiments, the indoor unit may also include a shell, and the shell may be configured to cover the outer surfaces of the first shell 20, the second shell 30 and the side panel 70, leaving only the exhaust port 15 and the air intake port 14 exposed to communicate with the outside world, so as to protect the first shell 20, the second shell 30 and the side panel 70.

[0048] The fan 91 can be arranged in a cylindrical strip shape. The fan 91 can be a crossflow fan, a centrifugal fan 91 or an axial flow fan 91, etc. When the fan 91 is configured as a crossflow fan, the crossflow fan has the advantages of small radial size, low rotation speed, low noise, uniform air output, etc., and its axial length can be arbitrarily lengthened without affecting the gas flow state, etc., and compared with the centrifugal fan 91 or the axial flow fan 91, the crossflow fan has a lower cost. And the fan 91 can be arranged opposite to the air suction port 14, so that the external airflow can flow to the fan 91 through the air suction port 14 in a shorter path, reducing the loss during the flow process.

[0049] The heat exchanger 92 is housed in the heat exchange chamber 13 and is connected to the air conditioner outdoor unit through a connecting pipe so that the refrigerant can circulate between the air conditioner outdoor unit and the air conditioner indoor unit. When hot air flows to the heat exchange chamber 13 and passes through the heat exchanger 92, the hot air will exchange heat with the refrigerant of the heat exchanger 92, so that the refrigerant can absorb heat, so that the heat can be transferred to the refrigerant to achieve a cooling effect. The heat exchanger 92 can be roughly V-shaped, so that the heat exchange area can be increased and the heat exchange efficiency can be improved. The heat exchanger 92 and the exhaust port 15 can be arranged opposite each other, so that the airflow can flow to the exhaust port 15 in a shorter path after flowing through the heat exchanger 92, so as to reduce the loss of the airflow during the flow process.

[0050] The electric control box assembly 93 can be installed on the surface of the air duct assembly 10 to achieve fixed installation. The electric control box assembly 93 can be electrically connected to the fan 91 and the heat exchanger 92 respectively to control or adjust the fan 91 and the heat exchanger 92. For example, when the temperature in the environment where the indoor unit 1 acts reaches a set value, the electric control box assembly 93 can send a command to turn off the fan 91 and the heat exchanger 92 to reduce energy consumption and prevent the indoor temperature from being too low or too high.

[0051] Furthermore, combining Figure 4 The electric control box assembly 93 can be installed on the surface of the lower shell 50 of the pressure diffuser chamber away from the pressure diffuser chamber 12, and is arranged adjacent to the air inlet 14 and facing the air inlet 14. In this way, maintenance personnel can directly disassemble and assemble the electric control box assembly 93 at a position adjacent to the air inlet 14. Since there is no other structure blocking the area adjacent to the air inlet 14, it is more convenient for maintenance personnel to disassemble and assemble the electric control box assembly 93. In some structural forms, the inner surface of the first shell 20 facing the pressure diffuser chamber 12 and the inner surface of the second shell 30 facing the pressure diffuser chamber 12 are provided with an insulation layer 80, and the insulation layer 80 can be an insulation sponge or insulation glue. In this way, by providing the insulation layer 80, the temperature in the air duct assembly 10 can be maintained to a certain extent, and the probability of the energy in the indoor unit 1 being dissipated outward through the first shell 20 and the second shell 30 can be reduced.

[0052] Reference Figures 4 to 6 In the embodiment of the present application, the second shell 30 includes a shell body 30A and a guide plate 30B connected to each other. The shell body 30A is provided with a reflux channel 31. The reflux channel 31 includes a reflux inlet 32 ​​and a reflux outlet 33. The reflux inlet 32 ​​is connected to the diffuser chamber 12, and the reflux outlet 33 is connected to the fan chamber 11.

[0053] It can be understood that in the direction from the pressure diffuser chamber 12 to the heat exchange chamber 13, the pressure diffuser chamber 12 is gradually expanded, and the lateral flow area of ​​the gas in the pressure diffuser chamber 12 gradually increases. As the lateral flow area of ​​the gas gradually increases, the flow rate of the gas gradually decreases, the dynamic pressure decreases, and the static pressure increases. A larger static pressure can help the airflow flowing out of the exhaust port 15 to overcome air resistance more effectively, so that it can reach a farther distance relative to the exhaust port 15. The reflow channel 31 is configured to connect the pressure diffuser chamber 12 and the fan chamber 11, the reflow inlet 32 ​​connects the pressure diffuser chamber 12, and the reflow outlet 33 connects the fan chamber 11. The airflow pressure (static pressure) in the pressure diffuser chamber 12 gradually increases, so that the airflow pressure at the reflow inlet 32 ​​is greater than the airflow pressure at the reflow outlet 33, so that part of the airflow entering the pressure diffuser chamber 12 is actively guided back to the air inlet side 91a of the fan 91 through the reflow channel 31. In this way, the vortex effect can be weakened, the operating efficiency of the fan 91 can be effectively improved, and the overall aerodynamic performance of the air duct assembly 10 can be enhanced. At the same time, after the vortex is weakened, the aerodynamic noise in the air duct assembly 10 can be reduced synchronously to enhance the user experience.

[0054] In some structural forms, the return channel 31 is arranged in a curve. Among them, the return channel 31 can be arranged in a curve such as an arc or a wave line, so that the impact speed of the airflow in the return channel 31 can be slowed down to further reduce the airflow noise and stabilize the airflow flow. It should be noted that the return channel 31 can also be arranged in a straight line in other embodiments, so that the air volume is increased at the same speed of the fan 91. Or the return channel 31 can also be a combination of a straight line and a curve, which can be selected by those skilled in the art according to needs.

[0055] Optionally, the width of the return channel 31 remains unchanged from the return inlet 32 ​​to the return outlet 33, so as to keep the airflow flowing stably when passing through the return channel, and then stably maintain the flow rate of the airflow through the return channel 31, so as to improve the effect of air replenishment and pressurization on the side of the fan close to the volute tongue. Or in another embodiment, the width of the return channel 31 is gradually expanded from the return inlet 32 ​​to the return outlet 33. That is, the change in the width of the return channel 31 gradually increases from the return inlet 32 ​​to the return outlet 33. In this way, the change in the width of the return channel 31 is initially small at the return inlet 32, so that the airflow is mixed evenly during the process of entering the return channel 31, and then the change in the width of the return channel 31 continues to increase, and under the condition of ensuring that there is no flow separation in the return channel 31, the change in width of the same channel length is as large as possible, so that the airflow flow rate can be guaranteed while reducing the airflow speed, thereby achieving the purpose of reducing noise.

[0056] By setting a guide plate 30B connected to the shell body 30A and located on one side of the air intake port 14, the airflow flowing through the return channel 31 is guided so that the airflow is more uniform and smooth and is directed to the fan 91 in the fan chamber 11, thereby reducing the influence of the airflow in the return channel 31 on the fan 91 in the fan chamber 11, thereby improving the working efficiency of the fan 91.

[0057] In some structural forms, the guide plate 30B is arranged at an angle, and the distance between the guide plate 30B and the air inlet 14 gradually increases in the direction away from the return outlet 33. The guide plate 30B can be directly bent and connected to the shell body 30A, or the guide plate 30B itself is bent, so that the distance between the guide plate 30B and the air inlet 14 gradually increases in the direction away from the return outlet 33, that is, the guide plate 30B is actually arranged away from the fan 91, so that the resonance between the fan 91 and the guide plate 30B is reduced when the fan 91 is transported, thereby further reducing the noise during the operation of the indoor unit 1 to improve the user experience.

[0058] In the related art, a reflow channel is usually set in the indoor unit in the air duct to reintroduce the airflow at the outlet side of the fan into the inlet side of the fan for pressurization. However, in this process, due to the gradient of upstream and downstream pressures of the reflow channel, a strong flow vortex appears at the tail of the reflow channel, resulting in a large noise generated by the duct machine, affecting the user experience.

[0059] In order to reduce the tail vortex noise of the return channel 31 during the use of the indoor unit 1 and improve the operating sound quality of the indoor unit 1, Figure 6The guide plate 30B of the present application is provided with an uneven portion 30b at the end away from the return outlet 33, so that the uneven portion 30b can break up the flow vortex at the return outlet 33 of the return channel 31, reducing the number of flow vortices contained in the airflow, thereby weakening the strength of the flow vortex, which is more conducive to the operation of the fan 91 in the fan chamber 11, and sending a more uniform and smooth airflow into the fan chamber 11, thereby improving the working efficiency of the indoor unit 1 and reducing the aerodynamic noise during the operation of the indoor unit 1, so as to enhance the user experience.

[0060] In some structural forms, the uneven portion 30b includes a tooth-like structure, and the tooth-like structure can effectively increase the contact area with the flow vortex, thereby improving the effect of breaking up the flow vortex. In another embodiment, the uneven portion 30b includes a wave-like structure, and the wave-like structure can effectively increase the contact area with the flow vortex, thereby improving the effect of breaking up the flow vortex. It should be noted that the uneven portion 30b can be arranged in a tooth-like structure, the uneven portion 30b can also be arranged in a wave-like structure, or the uneven portion 30b can be partially arranged in a tooth-like structure, or partially arranged in a wave-like structure.

[0061] Furthermore, when the uneven portion 30b includes a tooth-like structure, the tooth-like structure includes a plurality of sawteeth arranged in sequence along the axial direction of the fan chamber 11, and the tooth roots of the plurality of sawteeth are connected to each other. In this way, the number of the plurality of sawteeth is increased, thereby further increasing the area of ​​the tooth-like structure, further reducing the number of vortices contained in the airflow, thereby reducing the aerodynamic noise during the operation of the indoor unit 1, and improving the user experience.

[0062] In another embodiment, the tooth structure includes a plurality of saw teeth sequentially arranged along the axial direction of the fan chamber 11, and the tooth roots of the plurality of saw teeth are arranged at intervals. In this way, the tooth root intervals of the plurality of saw teeth can reduce the number of vortices contained in the airflow and reduce the overall weight of the tooth structure, thereby reducing the overall weight of the indoor unit 1.

[0063] Furthermore, in the axial direction of the fan chamber 11, the spacing distance between adjacent saw teeth in the middle is smaller than the spacing distance between adjacent saw teeth in the two sides. It is understandable that the air volume in the middle of the fan 91 located in the fan chamber 11 is usually greater than the air volume on the two sides, so that the air volume in the middle of the airflow entering the return air channel is also greater than the air volume on the two sides, so that the spacing distance between adjacent saw teeth in the middle is smaller than the spacing distance between adjacent saw teeth in the two sides, that is, the multiple saw teeth in the middle are denser than the multiple saw teeth in the two sides, thereby improving the effect of breaking up the flow vortex in the airflow.

[0064] In some structural forms, the end surface of the sawtooth away from the reflux outlet 33 is arranged in a plane. That is, the surface away from the tooth top of the sawtooth and away from the tooth root is arranged in a plane, so as to avoid the sharp end of the sawtooth causing easy scratches on the installer during installation, thereby improving the safety of installation, facilitating the sawtooth processing and improving the processing efficiency.

[0065] Optionally, the shapes of the multiple saw teeth are the same, and the width of the saw teeth gradually decreases in the direction of the guide plate 30B away from the return outlet 33. Thus, the saw teeth are formed into a triangular shape, and the outer contour of the saw teeth can be formed into a triangle. The triangular saw teeth can be easily processed, and at the same time, the width of the end of the saw teeth away from the return air outlet is smaller so that the flow vortex of the airflow will be broken up smaller, so as to achieve better noise reduction effect. Of course, the present embodiment is not limited to this, and the outer contour of the saw teeth can also be formed into a trapezoid, a semicircle or an ellipse, etc. The specific shape can be set by those skilled in the art according to the needs.

[0066] Reference Figure 7 and Figure 8 In some structural forms, the second housing 30 further includes a grille 98, which is detachably connected to the guide plate 30B and covers the air inlet 14. A plurality of through holes are formed on the grille 98, and the gas passing through the air inlet 14 can enter the fan chamber 11 through the plurality of through holes. The provision of the grille 98 can effectively prevent larger foreign matter from entering the fan chamber 11 and affecting the operation of the fan 91. The grille 98 is arranged in a grid shape to increase the through holes as much as possible and reduce the impact on the airflow. The grille 98 can be fixed to the guide plate 30B by snaps or screws, so as to facilitate early installation and later maintenance and disassembly, and can improve the stability of the installation of the grille 98, and there is no need to set up other structures separately to connect the grille 98, so as to reduce the number of structures of the air duct assembly 10, reduce the volume of the air duct assembly 10, and realize the miniaturization of the indoor unit 1. Of course, in order to further improve the stability of the connection of the grille 98, the grille 98 can also be additionally connected to the first housing 20, so as to further improve the stability of the connection of the grille 98.

[0067] Optionally, the grille 98 can be arranged in an arc shape as a whole. Alternatively, the grille 98 can also include a first grille and a second grille arranged at an angle, the first grille is connected to the first housing 20, and the second grille is connected to the guide plate 30B. The first grille and the second grille can be an integral structure with good integrity and easy processing, or the first grille and the second grille can also be a split structure and connected by bolt connection or welding. The first grille and the second grille arranged at an angle are far away from the fan 91, and there is sufficient space between the air inlet side 91a of the fan 91 and the grille 98, which is more convenient for the fan 91 to draw air.

[0068] Combined with reference Figure 4 , Figure 7as well as Fig. 9 In some structural forms, the shell body 30A includes a volute tongue 40, a diffuser lower shell 50, and a water receiving tray 60. The volute tongue 40 and the diffuser lower shell 50 define the bottom surface of the diffuser 12, and the side of the volute tongue 40 facing away from the fan chamber 11 cooperates with the diffuser lower shell 50 to form a return channel 31 and a return outlet 33, and the guide plate 30B is connected to the diffuser lower shell 50. The return inlet 32 ​​of the return channel 31 is opened on the bottom surface of the diffuser 12, and is located between the volute tongue 40 and the diffuser lower shell 50 or located at the diffuser lower shell 50.

[0069] It should be noted that the first shell 20 may include a fan chamber upper shell 21, a pressure diffuser chamber upper shell 22, and a heat exchange chamber upper shell 23 connected in sequence. In this way, the fan chamber upper shell 21 cooperates with the volute tongue 40 to define the fan chamber 11, the pressure diffuser chamber upper shell 22 cooperates with the volute tongue 40 and the pressure diffuser chamber lower shell 50 to define the pressure diffuser chamber 12, and the volute tongue 40 and the pressure diffuser chamber lower shell 50 define the cavity bottom surface of the pressure diffuser chamber 12, and the cavity bottom surface of the pressure diffuser chamber 12 is used to guide the airflow to the heat exchange chamber 13. Further, the fan chamber upper shell 21, the pressure diffuser chamber upper shell 22, and the heat exchange chamber upper shell 23 can be an integrated structure to improve the connection firmness of the three and reduce the assembly steps.

[0070] By arranging the reflux inlet 32 ​​between the volute tongue 40 and the lower shell 50 of the pressure diffuser chamber or on the lower shell 50 of the pressure diffuser chamber, when the airflow outflowing from the fan 91 is diverted by the volute tongue 40 to flow to the pressure diffuser chamber 12 and the side of the volute tongue 40 close to the air inlet side 91a, the pressure of the airflow flowing into the pressure diffuser chamber 12 after diversion becomes larger, so that the airflow pressure of the reflux inlet 32 ​​is greater than the airflow pressure of the reflux outlet 33, and then through the pressure difference between the reflux inlet 32 ​​and the reflux outlet 33, part of the airflow entering the pressure diffuser chamber 12 is actively guided back to the air inlet side 91a of the volute tongue 40 close to the fan 91 through the reflux channel 31 to work again, so that the airflow is easier to enter the reflux inlet 32. The water receiving tray 60 is located below the heat exchanger 92, used to receive the condensed water flowing out of the heat exchanger 92, and cooperates with the heat exchange chamber upper shell 23 of the first shell 20 to define the heat exchange chamber 13. Furthermore, the diffuser cavity lower shell 50 and the water receiving tray 60 can be an integrally formed component, so that the connection between the two is more secure, and the assembly steps are reduced to improve assembly efficiency. Of course, in other structural forms, the diffuser cavity lower shell 50 and the water receiving tray 60 can be a split structure, and the two can be fixed by a snap connection or a threaded connection, and the present application does not limit this.

[0071] Furthermore, in conjunction with reference Figure 6 , Fig. 9 as well as Fig.10The lower shell 50 of the pressure diffuser cavity includes a shell body 51 and a guide plate 52. The shell body 51 is connected to the volute tongue 40 and cooperates to define the cavity bottom surface of the pressure diffuser cavity 12. The guide plate 52 is detachably connected to the shell body 51 and is located on the side of the shell body 51 away from the pressure diffuser cavity 12. The side of the volute tongue 40 facing away from the fan cavity 11 cooperates with the guide plate 52 to form a return flow channel 31 and a return flow outlet 33. The guide plate 30B is connected to the end of the guide plate 52 away from the shell body 51.

[0072] Among them, the shell body 51 is the main structure of the lower shell 50 of the diffuser chamber, and the opposite sides of the shell body 51 are connected to the volute tongue 40 and the water receiving tray 60. It should be noted that the volute tongue 40 and the shell body 51 can be an integral structure to improve the overall structural strength. Of course, the two can also be connected in a detachable manner such as screws or snaps. In this way, according to the different air outlet conditions of the specific fan 91, an adapted volute tongue 40 can be selected for matching, or when the volute tongue 40 needs to be maintained, the maintenance personnel can also disassemble and assemble it. The reflux channel 31 is formed by the volute tongue 40 and the guide plate 52 of the lower shell 50 of the diffuser chamber, that is, the reflux channel 31 is formed by a split structural design, so that the shape of the reflux channel 31 can be changed by disassembly and assembly, so that the structural size of the reflux channel 31 can be accurately controlled, and the channel structure can be simplified and easy to open the mold. In order to improve the stability of the reflux channel 31, in the present application, when the volute tongue 40 is provided with a reinforcing rib 311 on the surface of the guide plate 52, a hook 3111 can be provided at the end of the reinforcing rib 311, and a buckle hole 52a is provided on the surface of the guide plate 52 facing the volute tongue 40, and the hook 3111 is engaged with the buckle hole 52a, so that the positions of the volute tongue 40 and the guide plate 52 are fixed. Of course, the volute tongue 40 and the guide plate 52 can also be fixed by other means such as screws, which can be selected by those skilled in the art. It is worth noting that the structural shape of the guide plate 52 is not limited, for example, it can be a curved guide plate 52 or a plane guide plate 52, etc. When the guide plate 52 is a curved guide plate 52, the guide effect can be improved, and when the guide plate 52 is a plane guide plate 52, the processing difficulty can be reduced.

[0073] Furthermore, the guide plate 30B and the guide plate 52 are an integral structure, for example, by integral injection molding, which can improve the firmness of the connection between the two and reduce the number of assembly steps.

[0074] In addition, it should be noted that the guide plate 52 can be fixed or movable.

[0075] For example, when the guide plate 52 is fixed, the installation angle can be pre-designed (for example, it can be tilted at a certain angle) so that it can more effectively control the direction of the airflow flowing out of the return outlet 33 and ensure the air volume. Thus, the guide plate 52 and the shell body 51 are an integral structure. For example, by integral injection molding, the firmness of the connection between the two can be improved and the assembly steps can be reduced.

[0076] When the guide plate 52 is movable, the guide plate 52 can be elastically swingable, that is, the guide plate 52 can be elastically swingable through the elastic part, so that the side of the volute 40 close to the air inlet side 91a of the fan 91 can be pressurized at different speeds by elastic adaptation, which reduces costs and has a good adjustable effect.

[0077] Furthermore, the guide plate 52 includes a connecting portion 521 and a guide portion 522 connected to each other, the connecting portion 521 is detachably connected to the shell body 51, and the guide portion 522 cooperates with the side of the volute tongue 40 facing away from the fan 91 to form the return channel 31 and the return outlet 33. The connecting portion 521 and the shell body 51 can be connected by screws or buckles, etc. The connecting portion 521 can be set in a flat plate and fit on the bottom surface of the shell body 51, so as to increase the contact area between the two, thereby improving the stability of the connection. The guide portion 522 is used to cooperate with the volute tongue 40 to form the return channel 31 and the return outlet 33, and the guide portion 522 can be set in an arc plate shape, so as to guide the flow direction of the airflow.

[0078] Reference Figure 6 In some structural forms, the outer wall surface of the volute tongue 40 includes a guide surface 41 and a diffuser surface 42. The guide surface 41 is configured to guide the airflow in the fan cavity 11 to flow into the diffuser cavity 12. The guide surface 41 extends from the side of the volute tongue 40 facing the fan cavity 11 to the diffuser cavity 12. The diffuser surface 42 is connected between the guide surface 41 and the top surface of the diffuser cavity lower shell 50, and the diffuser surface 42 and the top surface of the diffuser cavity lower shell 50 constitute the cavity bottom surface of the diffuser cavity 12. The top surface of the diffuser cavity lower shell 50 is provided with a reflux inlet 32.

[0079] Among them, the guide surface 41 can be set in an arc surface to change the direction of the airflow to reduce the airflow loss. The diffuser surface 42 can be set coplanar with the top surface of the diffuser chamber lower shell 50 so that the airflow can flow smoothly and reduce losses. By limiting the return inlet 32 ​​to be directly opened on the top surface of the diffuser chamber lower shell 50, the processing and manufacturing of the return inlet 32 ​​is more convenient, and the shape is easy to control, thereby ensuring the air intake of the return inlet 32, and facilitating the maintenance and replacement of the return inlet 32 ​​at a later time. In addition, the diffuser chamber lower shell 50 forms a guide slope at the return inlet 32, so as to further improve the airflow from the return inlet 32 ​​into the return channel 31.

[0080] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of this application, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate an orientation or position relationship based on the orientation or position relationship shown in the drawings, it is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0081] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An air duct assembly, applied to an indoor unit, characterized in that: The air duct assembly includes a first shell and a second shell, the first shell and the second shell cooperate to define a pressure diffuser cavity and a fan cavity that are connected, and an air suction port connected to the fan cavity, the second shell includes a shell body and a guide plate, the shell body is provided with a return channel, the return channel includes a return inlet and a return outlet, the return inlet is connected to the pressure diffuser cavity, and the return outlet is connected to the fan cavity; The guide plate is connected to the shell body and is located at one side of the air inlet. An uneven portion is provided at the end of the guide plate away from the return outlet.

2. The air duct assembly according to claim 1, characterized in that: The uneven portion includes a tooth-like structure and / or a wave-like structure.

3. The air duct assembly according to claim 2, characterized in that: When the uneven portion includes a tooth-like structure, the tooth-like structure includes a plurality of saw teeth arranged in sequence along the axial direction of the fan chamber, and the tooth roots of the plurality of saw teeth are connected to each other.

4. The air duct assembly according to claim 2, characterized in that: When the uneven portion includes a tooth-like structure, the tooth-like structure includes a plurality of saw teeth arranged in sequence along the axial direction of the fan chamber, and the tooth roots of the plurality of saw teeth are arranged at intervals.

5. The air duct assembly according to claim 4, characterized in that: In the axial direction of the fan cavity, the spacing distance between adjacent saw teeth located in the middle is smaller than the spacing distance between adjacent saw teeth located on both sides.

6. The air duct assembly according to claim 3 or 4, characterized in that: The end surface of the saw teeth away from the reflux outlet is arranged in a plane; And / or, the plurality of saw teeth have the same shape, and the width of the saw teeth gradually decreases in the direction in which the guide plate moves away from the reflux outlet.

7. The air duct assembly according to any one of claims 1 to 5, characterized in that: The guide plate is arranged obliquely, and the distance between the guide plate and the air suction port gradually increases in the direction away from the return outlet; And / or, the second shell further includes a grille, which is detachably connected to the guide plate and covers the air inlet.

8. The air duct assembly according to any one of claims 1 to 5, characterized in that: The shell body includes a volute tongue and a lower shell of the pressure diffuser chamber connected to each other, and the volute tongue and the lower shell of the pressure diffuser chamber define the bottom surface of the pressure diffuser chamber, the side of the volute tongue facing away from the fan chamber cooperates with the lower shell of the pressure diffuser chamber to form the return channel and the return outlet, and the guide plate is connected to the lower shell of the pressure diffuser chamber; The reflux inlet of the reflux channel is opened on the bottom surface of the diffuser chamber and is located between the volute tongue and the lower shell of the diffuser chamber or located on the lower shell of the diffuser chamber.

9. The air duct assembly according to claim 8, characterized in that: The lower shell of the pressure diffuser cavity comprises a shell body and a guide plate, wherein the shell body is connected to the volute tongue and cooperates to define the bottom surface of the pressure diffuser cavity; The guide plate is detachably connected to the shell body and is located on the side of the shell body away from the diffusion chamber. The side of the volute tongue facing away from the fan chamber cooperates with the guide plate to form the return channel and the return outlet. The guide plate is connected to one end of the guide plate away from the shell body.

10. The air duct assembly according to claim 9, characterized in that: The guide plate and the flow guide plate are an integrated structure.

11. The air duct assembly according to claim 8, characterized in that: The outer wall surface of the volute tongue includes a guide surface and a pressure diffuser surface, the guide surface is configured to guide the airflow in the fan cavity to flow into the pressure diffuser cavity, the guide surface extends from the side of the volute tongue toward the fan cavity to the pressure diffuser cavity, the pressure diffuser surface is connected between the guide surface and the top surface of the lower shell of the pressure diffuser cavity, and the pressure diffuser surface and the top surface of the lower shell of the pressure diffuser cavity constitute the cavity bottom surface of the pressure diffuser cavity; The top surface of the lower shell of the pressure diffuser chamber is provided with the reflux inlet.

12. The air duct assembly according to any one of claims 1 to 5, characterized in that: The width of the reflux channel is constant or gradually expanded from the reflux inlet toward the reflux outlet.

13. An indoor unit, characterized in that: It comprises a fan and an air duct assembly as described in any one of claims 1 to 11, and the fan is accommodated in the fan cavity.

14. A HVAC system, characterized in that: It comprises an outdoor unit and the indoor unit as claimed in claim 13, wherein the indoor unit and the outdoor unit form a refrigerant cycle.

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