Air duct assembly, indoor unit and heating and ventilation system

Abstract

The invention discloses an air duct assembly, an indoor unit and a heating and ventilation system. The air duct assembly is applied to the indoor unit, the indoor unit comprises a fan and a heat exchanger, the air duct assembly comprises a first shell and a second shell, the first shell and the second shell are matched to define a diffusion cavity and a heat exchange cavity which communicate with each other, the diffusion cavity is configured to communicate with the air outlet side of the fan and guide air to flow to the heat exchange cavity, and the heat exchange cavity is configured to contain the heat exchanger. The diffusion cavity is located on one side of the heat exchange cavity. According to the technical scheme, the air supply distance can be increased, noise is reduced, and the air supply effect is improved.

Description

Technical Field

[0001] This application relates to the field of heating, ventilation, and air conditioning (HVAC) technology, and particularly to an air duct assembly, an indoor unit, and an HVAC system. Background Art

[0002] The HVAC system includes an indoor unit, and the indoor unit has an air duct assembly for forming an air duct. The air duct assembly is formed with a diffuser cavity and a heat exchange cavity. The diffuser cavity is used to receive the air flow blown by the fan of the indoor unit and perform diffusion, and the heat exchange cavity is used to arrange a heat exchanger.

[0003] In the related art, the gas flow performance of the air flow blown by the fan in the above air duct is poor, resulting in a large noise during air supply, a poor air supply effect, and relatively affecting the user experience. Summary of the Invention

[0004] Embodiments of the present application provide an air duct assembly, an indoor unit, and an air duct machine, which can improve the air supply effect.

[0005] In a first aspect, an embodiment of the present application provides an air duct assembly applied to an indoor unit. The indoor unit includes a fan and a heat exchanger. The air duct assembly includes a first housing and a second housing. The first housing and the second housing cooperate to define a connected diffuser cavity and a heat exchange cavity. The diffuser cavity is configured to communicate with the downstream of the fan and guide the gas to flow to the heat exchange cavity. The heat exchange cavity is configured to accommodate the heat exchanger.

[0006] Wherein, the diffuser cavity is located on one side of the heat exchange cavity.

[0007] In an embodiment, between the diffuser cavity and the heat exchanger, the air duct assembly does not form an obstruction in the flow direction of the gas flowing to the heat exchanger.

[0008] In an embodiment, the diffuser cavity does not extend into the heat exchange cavity.

[0009] In an embodiment, along the direction from the diffuser cavity to the heat exchange cavity, the transverse flow area of the gas in the diffuser cavity is increased, and from the diffuser cavity to the heat exchange cavity, the transverse flow area of the gas remains unchanged or increases.

[0010] In an embodiment, along the direction from the diffuser cavity to the heat exchange cavity, the diffuser cavity is gradually expanded.

[0011] In an embodiment, the first housing includes an upper shell of the diffuser cavity and an upper shell of the heat exchange cavity. The upper shell of the diffuser cavity defines the top wall of the diffuser cavity. The upper shell of the heat exchange cavity defines the top wall of the heat exchange cavity. The second housing includes a lower shell of the diffuser cavity and a water receiving tray. The lower shell of the diffuser cavity defines the bottom wall of the diffuser cavity. The water receiving tray defines the bottom wall of the heat exchange cavity.

[0012] The diffuser chamber upper shell is connected to the heat exchange chamber upper shell, and the diffuser chamber lower shell is connected to the water receiving tray. On the upstream side of the heat exchange chamber, the heat exchange chamber upper shell extends upward relative to the diffuser chamber upper shell, and / or, on the upstream side of the heat exchange chamber, the water receiving tray extends downward relative to the diffuser chamber lower shell, so as to increase the flow area of the gas.

[0013] In one embodiment, the diffuser chamber upper shell is inclined upward in a direction away from the heat exchange chamber upper shell. The heat exchange chamber upper shell includes a connected shell top wall and a shell side wall. The shell side wall is connected between the diffuser chamber upper shell and the shell top wall, and the shell side wall extends upward.

[0014] In one embodiment, the diffuser chamber lower shell is inclined upward in a direction away from the water receiving tray, and the diffuser chamber lower shell and the water receiving tray are in smooth transition.

[0015] In one embodiment, the water receiving tray includes a tray bottom wall and a tray side wall. The tray side wall is connected between the diffuser chamber lower shell and the tray bottom wall, and an angle greater than or equal to 90 degrees is formed between the diffuser chamber lower shell and the tray side wall.

[0016] In one embodiment, the first housing includes a diffuser chamber upper shell and a heat exchange chamber upper shell. The diffuser chamber upper shell defines the chamber top wall of the diffuser chamber, and the heat exchange chamber upper shell defines the chamber top wall of the heat exchange chamber. The second housing includes a shell main body and a water receiving tray. The shell main body defines at least part of the chamber bottom wall of the diffuser chamber, and the water receiving tray defines the chamber bottom wall of the heat exchange chamber;

[0017] Wherein, the diffuser chamber upper shell and the heat exchange chamber upper shell are integrally formed components, and / or, the shell main body and the water receiving tray are integrally formed components.

[0018] In one embodiment, the first housing and the second housing further cooperate to define an air inlet chamber configured to house the fan, and the downstream side of the air inlet chamber communicates with the diffuser chamber;

[0019] The first housing includes a diffuser chamber upper shell, a heat exchange chamber upper shell, an air inlet chamber upper shell, and an air inlet chamber rear shell. The diffuser chamber upper shell, the heat exchange chamber upper shell, the air inlet chamber upper shell, and the air inlet chamber rear shell are integrally formed components.

[0020] In one embodiment, the first housing and the second housing further cooperate to define an air inlet chamber configured to house the fan, and the downstream of the air inlet chamber communicates with the diffuser chamber;

[0021] The air duct assembly further includes a volute tongue disposed at the transition between the air inlet cavity and the diffuser cavity. The volute tongue is configured to guide the air flow from the air inlet cavity to the diffuser cavity, and a plurality of diversion grooves are spaced on one side of the volute tongue facing the air inlet cavity. The diversion grooves extend from the air inlet cavity to the diffuser cavity.

[0022] In one embodiment, the volute tongue includes:

[0023] A plurality of diversion ribs protruding from the main body surface at intervals along the length direction of the air duct assembly. A diversion groove is jointly defined between two adjacent diversion ribs and the main body surface.

[0024] In one embodiment, when projected along the length direction of the air duct assembly, the main body surface part of the bottom of the diversion groove forms a bottom profile line, and the end point of the contour line of the diversion rib extending towards the lower housing of the diffuser cavity intersects with the bottom profile line.

[0025] In one embodiment, the connection between the two ends of the diversion rib and the main body surface is in a smooth transition;

[0026] And / or, the contour line shape of the diversion rib is configured as a wavy shape, a broken line shape, or a single arc shape that bulges away from the main body of the volute tongue.

[0027] In one embodiment, the second housing includes a first split structure and a second split structure. The first split structure is detachably connected to the second split structure, and the first split structure and the second split structure cooperate to define the bottom wall of the diffuser cavity and a part of the inner wall of the air inlet cavity;

[0028] Wherein, a part of the second split structure defines the volute tongue.

[0029] In one embodiment, the first split structure includes:

[0030] A housing main body; and

[0031] A support part connected to one side of the housing main body and detachably connected to the second split structure. The support part, the housing main body, and the second split structure cooperate to define the bottom wall of the diffuser cavity;

[0032] Wherein, the support structure and the housing main body are an integral structure, and / or a hollow cavity is formed by enclosing the second split structure and the support part.

[0033] In one embodiment, the first housing and the second housing further cooperate to define an air inlet cavity communicating with the diffuser cavity. The air inlet cavity is configured to receive the fan;

[0034] The second housing includes a return air channel, a first surface forming the bottom wall of the diffuser chamber, and a second surface forming a part of the chamber wall surface of the air inlet chamber. The first surface is provided with a first opening, the second surface is provided with a second opening, and the return air channel extends from the first opening to the second opening.

[0035] In one embodiment, the return air channel is curved.

[0036] And / or, the width dimension of the return air channel remains unchanged or is gradually expanded from the first opening to the second opening.

[0037] In one embodiment, the extension line of the orientation of the second opening of the return air channel passes through the fan, and the included angle with the outer peripheral tangent of the fan is θ, and the θ is less than or equal to 15 degrees and greater than or equal to 0 degrees.

[0038] Or, the extension line of the orientation of the second opening of the return air channel passes through the outside of the fan, and the included angle with the outer peripheral tangent of the fan is β, and the β is less than or equal to 45 degrees and greater than or equal to 0 degrees.

[0039] In one embodiment, the θ is equal to 0 degrees or the β is equal to 0 degrees, so that the extension line of the orientation of the second opening of the return air channel coincides with the outer peripheral tangent of the fan.

[0040] In one embodiment, the second housing includes:

[0041] A housing main body, and the housing main body is provided with the first surface.

[0042] A support portion, the support portion is connected to a side of the housing main body facing away from the first surface, and one side of the support portion is configured as a first air return surface; and

[0043] A deflector, the deflector is connected to a side of the housing main body facing away from the first surface and is spaced from the support portion. One side of the deflector facing the support portion is configured as a second air return surface. The second air return surface and the first air return surface cooperate to form the return air channel, and the end of the deflector away from the housing main body is provided with the second surface.

[0044] In one embodiment, the deflector includes a connecting portion, a deflecting portion, and a cavity wall portion. The connecting portion is stacked on a side of the housing body facing away from the first surface and is detachably mounted on the housing body. The deflecting portion is connected to the connecting portion and is disposed at an angle to the connecting portion. The cavity wall portion is connected to an end of the deflecting portion facing away from the connecting portion and extends in a direction away from the housing body. The cavity wall portion is disposed at an angle to the deflecting portion. The cavity wall portion has the second surface, and the first housing at least defines the air inlet cavity together with the cavity wall portion.

[0045] In one embodiment, a grille is further included. The grille is detachably connected to the cavity wall portion and covers an air inlet side of the air inlet cavity.

[0046] In a second aspect, an indoor unit according to an embodiment of the present application further includes a fan, a heat exchanger, and an air duct assembly as described in any one of the above. The first housing and the second housing further cooperate to define an air inlet cavity communicating with the diffuser cavity. The fan is received in the air inlet cavity, and the heat exchanger is received in the heat exchange cavity.

[0047] In one embodiment, the indoor unit is a duct unit, and the fan is a cross-flow fan.

[0048] In one embodiment, the first housing and the second housing further cooperate to form an air outlet communicating with the heat exchange cavity. The heat exchanger is arranged in an arc shape arched toward the air outlet. Among them, the central axis of the diffuser cavity passes through the top of the arc of the heat exchanger.

[0049] In one embodiment, a plurality of refrigerant pipes perpendicular to the air outlet direction are provided in the heat exchanger. Along the up-and-down direction of the installation environment, the number of refrigerant pipes in the middle of the heat exchanger is more than the number of refrigerant pipes at the upper and lower ends of the heat exchanger.

[0050] And / or, the air outlet faces the horizontal direction.

[0051] In one embodiment, the first housing and the second housing further cooperate to define an air suction port communicating with the air inlet cavity, and at least a part of the air suction port faces downward.

[0052] In one embodiment, the indoor unit further includes:

[0053] An electric control box, which is installed outside the second housing, and part of the air suction port is located between the fan and the electric control box.

[0054] In a third aspect, an embodiment of the present application provides a heating, ventilation, and air conditioning (HVAC) system, including an outdoor unit and an indoor unit as described in any one of the above. The outdoor unit and the heat exchanger form a refrigerant cycle.

[0055] In the embodiment of the present application, through the diffuser cavity provided on one side of the heat exchange cavity, along the direction from the diffuser cavity to the heat exchange cavity, when the air flow flows in the diffuser cavity, the flow rate of the gas gradually decreases, the dynamic pressure becomes smaller, while the dynamic pressure of the gas becomes smaller, the static pressure of the gas becomes larger, so that the static pressure of the gas when flowing out of the air outlet is relatively large, thereby effectively improving the static pressure level at the air outlet of the air duct assembly and increasing the air supply distance. In addition, the slowing down of the gas flow rate not only enables the gas to fully exchange heat with the heat exchanger when passing through the heat exchange cavity, improving the heat exchange efficiency, but also due to the decrease in the flow rate, the noise during air supply will be effectively reduced, and the air supply quality is improved. In the technical solution of the present application, the air supply distance of the indoor unit is increased, the noise is reduced, the air supply quality is better, thereby improving the air supply effect and the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0057] Figure 1 Structural schematic diagram of an embodiment of the indoor unit of the present application;

[0058] Figure 2 For Figure 1 Exploded structure diagram of the indoor unit in

[0059] Figure 3 For Figure 1 Front view of the indoor unit in

[0060] Figure 4 For Figure 3 Cross-sectional structure schematic diagram of the indoor unit at A-A in

[0061] Figure 5 Internal structure top view of an embodiment of the indoor unit of the present application;

[0062] Figure 6 For Figure 1 Exploded structure diagram of another embodiment of the indoor unit in

[0063] Figure 7 For Figure 3 Cross-sectional structure schematic diagram of the indoor unit at B-B in

[0064] Figure 8 Partial structure schematic diagram of an embodiment of the first housing of the present application;

[0065] Figure 9 Structural schematic diagram of an embodiment of the second housing of the present application;

[0066] Figure 10 is Figure 9 a schematic structural view of the second housing in [[ID=]], at another angle;

[0067] Figure 11 is Figure 9 a front view of the second housing in [[ID=]];

[0068] Figure 12 is Figure 11 a sectional view taken along C-C in [[ID=]];

[0069] Figure 13 an exploded structural view of another embodiment of the indoor unit of the present application;

[0070] Figure 14 a schematic structural view of another embodiment of the indoor unit of the present application;

[0071] Figure 15 is Figure 14 a sectional view taken along D-D shown in [[ID=]];

[0072] Figure 16 is Figure 15 a partial schematic view of the sectional view shown in [[ID=]];

[0073] Figure 17 a partial structural schematic view of another embodiment of the second housing of the present application;

[0074] Figure 18 is Figure 17 a partial enlarged view at F in [[ID=]];

[0075] Figure 19 is Figure 17 a partial exploded structural view of the second housing shown in [[ID=]];

[0076] Figure 20 is Figure 17 a partial structural schematic view of the second housing from a top-down perspective shown in [[ID=]].

[0077] Figure 21 is Figure 3 another sectional structural view of the indoor unit along A-A in [[ID=]];

[0078] Figure 22 a partial enlarged sectional view of the air duct assembly of the indoor unit of the present application;

[0079] Figure 23 a sectional view of the air duct assembly of the present application;

[0080] Figure 24 a schematic structural view of the indoor unit of the present application after the first housing is disassembled;

[0081] Figure 25 isFigure 24 Partial enlarged view at position I;

[0082] Figure 26 Schematic diagram of a partial structure of the second housing of the air duct assembly of the present application;

[0083] Figure 27 is Figure 26 Partial enlarged view at position N;

[0084] Figure 28 Schematic diagram of the structure of the flow guiding part of the air duct assembly of the present application;

[0085] Figure 29 Schematic diagram of the three - dimensional structure of the indoor unit provided by an embodiment of the present application from another perspective;

[0086] Figure 30 Exploded view of the indoor unit provided by an embodiment of the present application;

[0087] Figure 31 Schematic diagram of the partial structure of the indoor unit provided by an embodiment of the present application;

[0088] Figure 32 Cross - sectional view of the partial structure of the indoor unit provided by an embodiment of the present application;

[0089] Figure 33 Schematic diagram of the structure of the electronic control box in the indoor unit provided by an embodiment of the present application;

[0090] Figure 34 is Figure 32 Schematic diagram of the enlarged partial structure at position Q;

[0091] Figure 35 is Figure 32 Schematic diagram of the enlarged partial structure at position R;

[0092] Figure 36 Schematic diagram of the connection structure between the second housing and the electronic control box in the indoor unit provided by an embodiment of the present application;

[0093] Figure 37 Schematic diagram of the positioning structure between the electronic control box and the lower housing of the diffuser chamber in the indoor unit provided by an embodiment of the present application.

[0094] Explanation of the reference numerals in the drawings:

[0095] 1. Indoor unit; 101. Air duct air inlet interface; 102. Air duct air outlet interface; 10. Air duct assembly; 11. Air inlet chamber; 12. Diffuser chamber; 121. Diffuser section; 1211. First straight contour line; 13. Heat exchange chamber; 131. Pre-heat exchange chamber; 132. Post-heat exchange chamber; 14. Air suction port; 141. First return air inlet; 143. Second return air inlet; 15. Air outlet; 16. Hollow cavity; 17. Communication port; 18. Installation chamber; 181. First side wall; 182. Second side wall; 183. Exposure opening; 20. First housing; 20a. Cover; 21. Upper shell of air inlet chamber; 22. Upper shell of diffuser chamber; 23. Upper shell of heat exchange chamber; 231. Top wall of shell; 233. Side wall of shell; 24. First reinforcing rib; 25. Air deflector; 251. Connection part; 253. Guide part; 26. Rear shell of air inlet chamber; 30. Second housing; 31. First split structure; 311. Main body of shell; 312. Support part; 312a. First return air surface; 3121. First connection part; 3122. Second connection part; 32. Second split structure; 321. First plate section; 322. Second plate section; 323. Third plate section; 33. Front shell of air inlet chamber; 40. Volute tongue; 41. Main body of volute tongue; 411. Main body surface; 412. First windward section; 413. First air guiding section; 414. First arc contour line; 42. Flow guiding rib; 423. Second windward section; 424. Second air guiding section; 425. Second arc contour line; 426. Second straight contour line; 43. Flow guiding groove; 431. Bottom line of groove; 45. Concave cavity; 46. Intersection line; 34. First surface; 35. Second surface; 36. Return channel; 37. First opening; 38. Second opening; 39. Pipe routing part; 391. First connecting plate; 392. Second connecting plate; 393. Through hole; 50. Flow guiding part; 51. Connection part; 52. Flow guiding part; 521. Second return air surface; 522. Positioning opening; 53. Chamber wall part; 531. Fixed card slot; 55. Flow guiding rib; 551. Third surface; 552. Fourth surface; 553. Block; 60. Water receiving tray; 60a. Bottom wall of tray; 60b. Side wall of tray; 61. Water receiving part; 611. Water receiving groove; 612. Overlapping boss; 62. Drainage part; 621. Water storage groove; 622. Drain pipe; 623. Water pump installation block; 70. Side enclosure panel; 80. Thermal insulation layer; 81. Upper thermal insulation layer; 83. Lower thermal insulation layer; 83. Sheet metal part; 91. Fan; 91a. Air inlet side; 91b. Air outlet side; 911. Impeller; 913. Motor; 92. Heat exchanger; 921. Refrigerant pipe; 93. Electric control box; 93a. Accommodation chamber; 93b. Positioning column; 93c. Positioning groove; 931. Box body; 9317. Wire passing hole; 9318. Second heat dissipation hole; 932. Box cover; 9321. First heat dissipation hole; 9323. Electric control box flow guiding part; 9325. Electric control box flow guiding surface; 933. Electric control board assembly; 98. Protection grille; 981. First grille part; 983. Second grille part.

[0096] The realization of the purpose of this application, its functional features and advantages will be further described in conjunction with the embodiments and with reference to the accompanying drawings. Detailed implementation manners

[0097] To make the purpose, technical solutions and advantages of this application clearer, the following will further describe the embodiments of this application in detail with reference to the accompanying drawings.

[0098] When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with this application. On the contrary, they are merely examples of devices and methods that are consistent with some aspects of this application as detailed in the appended claims.

[0099] In the description of this application, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances. In addition, in the description of this application, unless otherwise stated, "a plurality of" means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0100] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of 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.

[0101] Please refer to Figure 1 and Figure 2 , an embodiment of this application provides a heating, ventilation and air conditioning (HVAC) system. The HVAC system includes an indoor unit 1 and an outdoor unit. The indoor unit 1 is connected to the outdoor unit through cables, pipelines, etc. to jointly operate to regulate the indoor environment.

[0102] In this application, the up-down direction ZZ, the front-back direction YY and the left-right direction XX are defined, and the up-down direction ZZ, the front-back direction YY and the left-right direction XX are arranged at an angle to each other in pairs.

[0103] It can be understood that the indoor unit 1 is arranged indoors and is usually installed in the form of a ceiling for supplying air indoors. The indoor unit 1 includes a duct assembly 10, a fan 91, a heat exchanger 92 and an electric control box 93.

[0104] Among them, the air duct assembly 10 is used to construct an air duct suitable for the indoor unit 1 for gas flow. Specifically, the air duct assembly 10 is a structure mainly composed of a housing, and the outer contour of the air duct assembly 10 can be longitudinally elongated.

[0105] Please refer to Figure 3 and Figure 4 , the air duct assembly 10 is formed with an air inlet chamber 11, a diffuser chamber 12 and a heat exchange chamber 13 that are connected in sequence, and an air suction port 14 communicating with the air inlet chamber 11 and an air outlet 15 communicating with the heat exchange chamber 13 are formed, so that gas can enter the air duct assembly 10 from the air suction port 14, and sequentially pass through the air inlet chamber 11, the diffuser chamber 12 and the heat exchange chamber 13, and finally flow out from the air outlet 15.

[0106] The blower 91 is arranged in the air inlet chamber 11, and can extract the gas at the air suction port 14 and do work on it to make it flow to the diffuser chamber 12, providing power for the gas circulation of the above air duct. The blower 91 can be a cross-flow blower 91, a centrifugal blower 91 or an axial-flow blower 91, etc. As Figure 5 shown, taking the cross-flow blower 91 as an example, the blower 91 includes an impeller 911 and a motor 913. The impeller 911 is arranged in a long cylindrical shape. The motor 913 is arranged at one end of the impeller 911 and connected to the housing, and the output shaft of the motor 913 is connected to the impeller 911. One side in the circumferential direction of the impeller 911 is generally oriented towards the air suction port 14, and this side of the impeller 911 is defined as the air inlet side 91a; the other side in the circumferential direction of the impeller 911 that is spaced from the air inlet side 91a is generally oriented towards the diffuser chamber 12, and this side of the impeller 911 is defined as the air outlet side 91b. A plurality of blades are distributed along the circumferential direction of the impeller 911. When the motor 913 drives the impeller 911 to rotate, the rotating blades can cause the gas to flow from the air inlet side 91a to the air outlet side 91b. The cross-flow blower has the advantages of energy saving, large air volume, low noise and simple installation. Combining Figure 4 with Figure 5 , the heat exchanger 92 is housed in the heat exchange chamber 13 and is used for heat exchange with the gas flowing through the heat exchange chamber 13 and passing through the heat exchanger 92, playing a role in cooling or heating the gas. For example, a plurality of refrigerant pipes 921 are arranged inside the heat exchanger 92, and the gas exchanges heat with the refrigerant in the pipes when passing through the heat exchanger 92, thereby changing the gas temperature. When refrigerating, the gas exchanges heat with the refrigerant of the heat exchanger 92 to form cold air; when heating, the gas exchanges heat with the refrigerant of the heat exchanger 92 to form heated air. The shape of the heat exchanger 92 in this application can be in various shapes such as linear, V-shaped, arc-shaped or wavy, as long as it can exchange heat with the gas.

[0107] An electronic control box 93 is provided with an electronic control board assembly 933. A variety of electronic components are integrated on the electronic control board assembly 933, which are used for electrically connecting devices such as a blower 91 and for overall control of the overall operating conditions of the indoor unit 1. Inevitably, a relatively large amount of heat is generated during the operation of the electronic components. In the embodiments of the present application, the electronic control box 93 can be disposed in the air duct formed by the air duct assembly 10 or disposed close to the air duct, so as to dissipate heat from the electronic control box 93 to a certain extent by means of the air duct, avoiding device operation failures or damages caused by overheating of the electronic control board assembly 933, improving the operating stability of the indoor unit 1, and extending the service life.

[0108] The following will explain the relevant structures of the air duct assembly 10 with reference to the drawings. Please refer to Figure 6 , in some embodiments of the present application, for the convenience of assembling the indoor unit 1, the housing includes a first housing 20 and a second housing 30. The first housing 20 and the second housing 30 are connected to splice to form the above-mentioned housing. Among them, the first housing 20 and the second housing 30 can be made of metal materials such as aluminum alloy or stainless steel respectively to meet requirements such as high strength and corrosion resistance. Alternatively, the first housing 20 and the second housing 30 can also adopt plastic materials to achieve the lightweight of the housing. The present application does not limit this. For example, the housing can adopt a combination of the first housing 20 being made of metal material and the second housing 30 being made of plastic material. In addition, the embodiments of the present application do not limit the connection manner between the first housing 20 and the second housing 30. They can be connected separately or in combination by means of snap connection, riveting, welding, and bolt connection, etc.

[0109] Specifically, please combine Figure 2 and Figure 6 , the first housing 20 includes a cover 20a and two side panels 70. The two side panels 70 are spaced apart in the left-right direction XX, defining the width of the first housing 20; the cover 20a is generally disposed above the two side panels 70 and extends along the front-back direction YY. The two sides of the cover 20a along the left-right direction XX are respectively connected to the two side panels 70; thus, the cover 20a and the two side panels 70 are spliced to form the first housing 20 in a shape of a cover shell. Of course, the cover 20a and the side panel 70 can be integrally provided or separately provided, and the two can be made of the same or different materials and connected by means of snap connection, riveting, welding, and bolt connection, etc. The present application will not elaborate here. Correspondingly, the second housing 30 is spaced apart from the cover 20a in the up-down direction ZZ and also extends along the front-back direction YY. The second housing 30 is disposed between the two side panels 70, and the two sides of the second housing 30 along the left-right direction XX are respectively connected to the two side panels 70. In this way, the first housing 20, the second housing 30, and the two side panels 70 are spliced to form the above-mentioned housing.

[0110] Please refer to Figure 6and Figure 7 , at least one of the first housing 20 and the second housing 30 forms the above-mentioned air suction port 14. That is to say, the air suction port 14 can be provided on the first housing 20 or the second housing 30, or can be configured by the first housing 20 and the second housing 30. As Figure 7 shown, along the front-rear direction YY from the rear to the front, the cover body 20a includes a rear housing 26 of the air inlet cavity, an upper housing 21 of the air inlet cavity, an upper housing 22 of the diffuser cavity, and an upper housing 23 of the heat exchange cavity connected in sequence. The second housing 30 includes a front housing 33 of the air inlet cavity, a housing main body 311, and a water receiving tray 60 connected in sequence. The rear housing 26 of the air inlet cavity and the front housing 33 of the air inlet cavity are spaced apart in the front-rear direction YY. The rear housing 26 of the air inlet cavity, the upper housing 21 of the air inlet cavity, the front housing 33 of the air inlet cavity, and the side wall 70 define the air inlet cavity 11. The fan 91 is arranged in the air inlet cavity 11 and extends along the left-right direction XX. The air inlet cavity 11 communicates with the air suction port 14, and the air inlet side 91a of the fan 91 faces the air suction port 14, so that the fan 91 can extract the air near the air suction port 14 through the air suction port 14.

[0111] Please continue to refer to Figure 7 , in an embodiment, the upper housing 21 of the air inlet cavity defines the top wall of the air inlet cavity 11, and the rear housing 26 of the air inlet cavity defines the rear side wall of the air inlet cavity 11.

[0112] From Figure 7 the perspective, the rear housing 26 of the air inlet cavity is located below the upper housing 21 of the air inlet cavity and is more outwardly extended relative to the upper housing 21 of the air inlet cavity. In other words, along the front-rear direction YY, the rear housing 26 of the air inlet cavity is farther from the volute tongue 40 than the upper housing 21 of the air inlet cavity, which is beneficial to increasing the air intake volume and can indirectly increase the air output volume.

[0113] In an embodiment, the fan 91 is a cross-flow fan 91. The air outlet side 91b of the impeller 911 (fan 91) communicates with the diffuser cavity 12. During the flow of the gas through the impeller 911, the gas forms an air flow vortex (eccentric vortex) with the center near the volute tongue 40, and the air flow streamline at the outer edge of the air flow vortex is set in an arc shape. Therefore, the inner contour line of the upper housing 21 of the air inlet cavity is also set in an arc shape and can be adaptively designed according to the air flow streamline of the fan 91, so that the gas can flow smoothly along the inner wall of the upper housing 21 of the air inlet cavity to the diffuser cavity 12, effectively reducing the pressure loss of the air flow in the air inlet cavity 11 and increasing the air volume entering the diffuser cavity 12. Compared with the related technology that uses a centrifugal fan 91, this embodiment of the present application uses a cross-flow fan 91, without considering the design and installation of the centrifugal housing structure outside the centrifugal fan 91, reducing the assembly difficulty and improving the production efficiency.

[0114] Please still refer to Figure 7, the diffuser chamber upper shell 22 is connected to the above-mentioned air inlet chamber upper shell 21 and the heat exchange chamber upper shell 23. The diffuser chamber upper shell 22 at least jointly encloses the diffuser chamber 12 with the shell main body 311 and the side wall plate 70. The heat exchange chamber upper shell 23 and the water receiving tray 60 and the side wall plate 70 enclose to form the heat exchange chamber 13.

[0115] Among them, in order to improve the structural strength, a first reinforcing rib 24 can be provided on the top surface of the diffuser chamber upper shell 22 (shown in Figure 4 ), and the first reinforcing rib 24 can extend from the diffuser chamber upper shell 22 to the air inlet chamber upper shell 21. Here, the extension length of the first reinforcing rib 24 is not specifically introduced. The shell can be provided with a plurality of first reinforcing ribs 24, and the plurality of first reinforcing ribs 24 are spaced apart along the width direction of the indoor unit 1 to further improve the structural strength.

[0116] Further, in an embodiment, please refer to Figure 2 and Figure 5 , the shell is also provided with two air guide plates 25. The two air guide plates 25 are respectively arranged on the inner side of the side wall plate 70 and cover the sides of the air inlet chamber 11 and at least part of the diffuser chamber 12. The air guide plate 25 includes a connected portion 251 and a guiding portion 253. The connecting portion 251 is located on both sides of the air inlet chamber 11 along the left-right direction XX and is used to install the fan 91 and cover the part of the motor 913 other than the impeller 911 to stabilize the air flow and make as much gas as possible flow to the diffuser chamber 12; the guiding portion 253 is located on both sides of the diffuser chamber 12. Among them, the guiding portion 253 is provided with a guiding surface on the side surface facing the inside of the diffuser chamber 12, and the guiding surface extends inward in the direction from the diffuser chamber 12 to the heat exchange chamber 13. This guiding surface mainly guides the air flow in the diffuser chamber 12, improves the air flow stability, and can make the air flow mostly pass through the middle part of the heat exchanger 92, improving the heat exchange efficiency.

[0117] One end of the second shell 30 close to the air inlet chamber 11 is provided with a volute tongue 40. The volute tongue 40 is specifically arranged at the transition between the air inlet chamber 11 and the diffuser chamber 12. The volute tongue 40 is used to divide the air flow on the air outlet side 91b of the fan 91. When the fan 91 is a cross-flow fan 91, the volute tongue 40 also plays a role in stabilizing the eccentric vortex, can increase the cross-flow area, and thus can increase the flow rate and head of the fan 91. The volute tongue 40 has a surface facing the diffuser chamber upper shell 22, and this surface and the diffuser chamber upper shell 22 define a part of the inlet section of the diffuser chamber 12. The air flow in this inlet section entering the diffuser chamber 12 from the air outlet side 91b of the fan 91 has a relatively high kinetic energy (dynamic pressure), and the potential energy (static pressure) of the air flow in the inlet section is small.

[0118] Please return to refer to Figure 7, along the front-rear direction YY, that is, along the direction from the diffuser chamber 12 to the heat exchange chamber 13, the transverse flow area of the gas in the diffuser chamber 12 is set to increase. For example, the wall surface of the upper shell 22 of the diffuser chamber or the wall surface of the shell main body 311 is arranged in a stepped manner, so that the transverse flow area of the gas in the diffuser chamber 12 increases step by step. When the air flow in the inlet section flows in the diffuser chamber 12, as the transverse flow area of the gas gradually becomes larger, the flow velocity of the gas gradually decreases, and the dynamic pressure becomes smaller. The smaller gas flow velocity enables the gas to fully exchange heat with the heat exchanger 92 when passing through the heat exchange chamber 13, improving the heat exchange efficiency. Moreover, since the gas flow velocity slows down, the noise during air supply also decreases. In addition, according to Bernoulli's law, when the dynamic pressure of the gas becomes smaller, the static pressure of the gas becomes larger. Therefore, the static pressure of the gas when flowing out from the air outlet 15 is relatively large. The relatively large static pressure can help the air flow flowing out from the air outlet 15 more effectively overcome the air resistance, so that it can reach a farther distance relative to the air outlet 15, enabling the indoor unit 1 to have a considerable air supply distance.

[0119] Furthermore, the diffuser chamber 12 can be arranged in a gradually expanding manner. In some embodiments, in the direction away from the water receiving tray 60, the shell main body 311 is inclined upward. The upper shell 22 of the diffuser chamber can be horizontally arranged, or the upper shell 22 of the diffuser chamber can also be arranged in an arc that fits the air flow streamline like the upper shell 21 of the air inlet chamber. In short, along the direction approaching the heat exchange chamber 13, the distance between the upper shell 22 of the diffuser chamber and the shell main body 311 gradually increases, so that the transverse flow area of the gas in the diffuser chamber 12 gradually becomes larger, making the air flow change more smoothly, reducing or avoiding the noise caused by air flow disorder, further reducing the noise of the indoor unit 1, and improving the air supply quality and air supply effect.

[0120] However, it can be understood that during the process of the air flow flowing from the inlet section of the diffuser chamber 12 into the heat exchange chamber 13, the dynamic pressure is not completely converted into static pressure, and there is still a small part of pressure loss. This part of pressure loss is divided into the frictional pressure loss and the local pressure loss of the gas. Among them, the frictional pressure loss refers to the pressure reduction caused by factors such as friction, resistance, and flow change during the flow of the fluid in the pipeline (duct assembly 10), which is inevitable; when the fluid flows through elbows, joints, etc. of the duct assembly 10, the magnitude and direction of the flow velocity change, generating vortices and turbulent phenomena, and the resulting pressure loss is called the local pressure loss.

[0121] In the related art, a partition is mostly used in the housing to separate the blower from the heat exchanger. When the gas flows from the air outlet side of the blower to the heat exchanger, part of it is blocked by the partition and vortices are generated. Moreover, the blower mostly has a volute, and most of the outlet section of the volute extends into the heat exchange cavity. There is a gap between the outlet section and the inner wall of the heat exchange cavity, and the air flow flowing out of the air outlet of the volute is also relatively likely to generate vortices at the above-mentioned gap. In the above situation, on the one hand, more local pressure losses are caused during the flow of the gas. When the dynamic pressure at the inlet section of the diffuser chamber is constant, the static pressure of the gas at the air outlet is small, which affects the air supply distance. On the other hand, the existence of vortices not only affects the operation state of the air flow, but also generates noise, which has a relatively large impact on the use experience. Obviously, the air supply distance and air supply quality of the air duct machine in the related art are affected, and the air supply effect is not very ideal.

[0122] Therefore, please refer to Figure 4 and Figure 7 In the embodiment of the present application, the diffuser chamber upper shell 22 is connected to the heat exchange chamber upper shell 23. The diffuser chamber upper shell 22 defines the top wall of the diffuser chamber 12, and the heat exchange chamber upper shell 23 defines the top wall of the heat exchange chamber 13. The housing main body 311 is connected to the water receiving tray 60. The housing main body 311 defines at least part of the bottom wall of the diffuser chamber 12, and the water receiving tray 60 defines the bottom wall of the heat exchange chamber 13. The diffuser chamber 12 is located on one side of the heat exchange chamber 13, and the diffuser chamber 12 does not extend into the heat exchange chamber 13. The end of the diffuser chamber upper shell 22 away from the air inlet chamber upper shell 21 is connected to the starting end of the heat exchange chamber upper shell 23 and does not extend into the heat exchange chamber 13. Similarly, the end of the housing main body 311 away from the volute tongue 40 is connected to the starting end of the water receiving tray 60 and does not extend into the heat exchange chamber 13. Thus, the top wall of the diffuser chamber 12 and the top wall of the heat exchange chamber 13 are directly connected, and the bottom wall of the diffuser chamber 12 and the bottom wall of the heat exchange chamber 13 are directly connected, and there is no overlapping area when projected along the vertical direction ZZ. There is no gap between the outlet section of the diffuser chamber 12 and the chamber wall of the heat exchange chamber 13, so that when the air flow flows out of the diffuser chamber 12, a turbulent air flow will not be formed in the gap between the chamber walls of the diffuser chamber 12 and the heat exchange chamber 13.

[0123] In this way, when the gas flows from the diffuser chamber 12 to the heat exchange chamber 13, since the diffuser chamber 12 and the heat exchange chamber 13 are directly connected and there is no part of the diffuser chamber 12 extending into the heat exchange chamber 13, this setting method can reduce or avoid disturbances such as vortex or turbulence generated near the communication port 17 when the gas flows out of the diffuser chamber 12, and can also reduce or avoid the formation of a disordered air flow in the gap between the walls of the diffuser chamber 12 and the heat exchange chamber 13, thereby reducing the pressure loss and reducing the noise. Through the above setting, the air duct assembly 10 of the embodiment of the present application can effectively reduce or avoid the pressure loss caused by vortex or variable cross-section in the air flow process from the diffuser chamber 12 to the heat exchange chamber 13, maximize the conversion of the dynamic pressure of the air flow on the air outlet side 91b of the fan 91 into static pressure, thereby effectively improving the static pressure level at the air outlet 15 of the indoor unit 1 and increasing the air supply distance. And due to the reduction of disturbances such as air flow vortices, the noise during the air supply of the indoor unit 1 will also be effectively reduced, and the air supply quality is improved.

[0124] Further, from the diffuser chamber 12 to the heat exchange chamber 13, the lateral flow area of the gas remains unchanged or increases. It should be noted that, please refer to Figure 7 , the diffuser chamber 12 and the heat exchange chamber 13 are connected through the communication port 17. Along the front-rear direction YY, at least in a part of the area from before the communication port 17 to after the communication port 17, for example, in the area after the middle section of the diffuser chamber 12 and before the heat exchanger 92, the lateral flow area of the gas remains unchanged or increases.

[0125] In some embodiments, the extending direction of the upper shell 23 of the heat exchange chamber is the same as that of the upper shell 22 of the diffuser chamber, and the extending direction of the water receiving tray 60 is the same as that of the shell main body 311. Or, the upper shell 23 of the heat exchange chamber extends more upward relative to the upper shell 22 of the diffuser chamber, and the water receiving tray 60 extends more downward relative to the shell main body 311, so that the lateral flow area of the gas remains unchanged or increases. And since the flow area of the gas remains unchanged or increases when the gas flows from the diffuser chamber 12 to the heat exchange chamber 13, it is possible to avoid the pressure loss of the gas caused by the reduction of the gas flow area, further improving the static pressure level at the air outlet 15 of the indoor unit 1 and increasing the air supply distance.

[0126] Such as Figure 7As shown, in some embodiments, between the diffuser chamber 12 and the heat exchanger 92, the air duct assembly 10 does not form an obstruction in the flow direction of the air flow towards the heat exchanger 92. For example, the air duct assembly 10 does not have a windward surface arranged at an angle to the flow direction of the gas. The windward surface refers to a surface in the air duct arranged at an angle to the flow direction of the gas. It can be understood that this angle is greater than 0 degrees, such as 60 degrees, 90 degrees, etc. Imagine that if there is a windward surface in the flow direction of the gas, the impact of the gas on the windward surface will cause energy loss, which is not conducive to the conversion of the dynamic pressure of the gas into static pressure. Therefore, in some embodiments of the present application, the inner wall of the diffuser chamber 12 is generally arranged in a flared shape; and in the part of the heat exchange chamber 13 close to the diffuser chamber 12, the inner walls of the heat exchange chamber 13, such as the top wall of the chamber defined by the upper shell 23 of the heat exchange chamber and the bottom wall of the chamber defined by the water receiving tray 60, are arranged in an outward-expanded shape relative to the communication port 17. In this way, during the process of the gas flowing from the diffuser chamber 12 to the heat exchange chamber 13 and before passing through the heat exchanger 92, there is no pressure loss caused by the obstruction of the windward surface, further improving the conversion rate of the dynamic pressure of the gas into static pressure.

[0127] Please refer to Figure 4 or Figure 7 , in a specific embodiment of the present application, on the upstream side of the heat exchange chamber 13, the upper shell 22 of the diffuser chamber slopes upward in the direction away from the upper shell 23 of the heat exchange chamber. The upper shell 23 of the heat exchange chamber includes a connected shell side wall 233 and a shell top wall 231. The shell side wall 233 is connected between the upper shell 22 of the diffuser chamber and the shell top wall 231, and the shell side wall 233 extends upward. In this embodiment, the shell side wall 233 extends vertically upward. In other embodiments, the shell side wall 233 may be: extending obliquely upward along the front-rear direction from the upper shell 22 of the diffuser chamber to the shell top wall, so that at the connection between the diffuser chamber 12 and the heat exchange chamber 13, it is arranged in an outward-expanded shape relative to the communication port 17, ensuring that there is no windward surface blocking the air flow above.

[0128] As Figure 8 shown, to make the connection between the upper shell 22 of the diffuser chamber and the upper shell 23 of the heat exchange chamber relatively smooth, a part of the section at the end of the upper shell 22 of the diffuser chamber close to the upper shell 23 of the heat exchange chamber is arranged horizontally, and the shell side wall 233 of the upper shell 23 of the heat exchange chamber forms a 90-degree angle with this section of the upper shell 22 of the diffuser chamber.

[0129] Further, the water receiving tray 60 defines the bottom wall of the heat exchange chamber 13 and is used to collect the water generated by heat exchange at the heat exchanger 92. On the upstream side of the heat exchange chamber 13, the housing main body 311 slopes upward in a direction away from the water receiving tray 60 to cooperate with the diffuser chamber upper housing 22 to form a gradually expanding diffuser chamber 12 structure. At the connection between the diffuser chamber 12 and the heat exchange chamber 13, the housing main body 311 and the water receiving tray 60 are smoothly transitioned to ensure a uniform flow field in the air duct, reduce or avoid the generation of turbulence when the air flow passes through the connection between the diffuser chamber 12 and the heat exchange chamber 13, thereby reducing the pressure loss and reducing the noise.

[0130] Specifically, in one embodiment, please refer to Figure 7 , the water receiving tray 60 includes a tray bottom wall 60a and a tray side wall 60b. The tray side wall 60b is connected between the housing main body 311 and the tray bottom wall 60a. An angle greater than or equal to 90 degrees is formed between the housing main body 311 and the tray side wall 60b to further smoothly introduce the lower air flow into the heat exchange chamber 13.

[0131] Thus, in one embodiment, the housing side wall 233 of the heat exchange chamber upper housing 23 extends upward, and the tray side wall 60b of the water receiving tray 60 extends downward. The section of the heat exchange chamber 13 close to the diffuser chamber 12 has a larger gas lateral flow area than the diffuser chamber 12, further reducing the pressure loss when the gas flows from the diffuser chamber 12 into the heat exchange chamber 13 and making the gas more uniform, improving the heat exchange efficiency with the heat exchanger 92.

[0132] Please refer to Figure 7 , in some embodiments, the air outlet 15 is provided on the side of the heat exchange chamber 13 away from the diffuser chamber 12. Taking the arc-shaped heat exchanger as an example, the heat exchanger 92 is arranged in an arc shape arched toward the air outlet 15. It can be understood that a plurality of refrigerant pipes 921 are provided in the heat exchanger 92. The plurality of refrigerant pipes 921 extend along the left-right direction XX and are arranged in the heat exchanger 92 along the up-down direction ZZ. In this embodiment, the central axis S of the diffuser chamber 12 (i.e., the dotted line in the figure) passes through the middle (the apex) of the heat exchanger 92. Along the up-down direction ZZ, the vicinity of the apex of the heat exchanger 92 is thicker than its upper and lower ends, and the number of refrigerant pipes 921 in the middle of the heat exchanger 92 is more than the number of refrigerant pipes 921 at the upper and lower ends of the heat exchanger 92. It can be understood that the gas in the central axis part of the diffuser chamber 12 is the mainstream area, and the gas flow rate and velocity in this area are large. In the embodiment of the present application, this part of the gas passes through the thickest area of the heat exchanger 92, which can effectively improve the heat exchange efficiency of the heat exchanger 92.

[0133] Such as Figures 9 to 12As shown, in some embodiments, the water receiving tray 60 includes a water receiving portion 61 and a drainage portion 62 connected to each other. The water receiving portion 61 is configured to carry the heat exchanger 92 and connect to the housing main body 311. The water receiving portion 61 is formed with a water receiving groove 611 that is open upward. A lapping boss 612 protrudes from the bottom wall of the water receiving groove 611. The lapping boss 612 is configured to carry the heat exchanger 92 and cooperate with the heat exchanger 92 to divide the heat exchange chamber 13 into a post-heat exchange chamber 131 and a pre-heat exchange chamber 132. The post-heat exchange chamber 131 communicates with the diffuser chamber 12, and the pre-heat exchange chamber 132 communicates with the air outlet 15.

[0134] When the heat exchanger 92 operates, some condensed water will be generated on its surface. The water generated on the surface of the heat exchanger 92 flows and converges into the water receiving groove 611 under the action of gravity. Installing and fixing the heat exchanger 92 on the lapping boss 612 can avoid the phenomenon that the heat exchanger 92 is soaked in water and causes the side plates of the heat exchanger 92 to rust, thereby extending the service life of the heat exchanger 92. The water receiving groove 611 communicates with the drainage portion 62, and the bottom wall of the water receiving groove 611 slopes downward in the direction towards the drainage portion 62, so as to further increase the flow rate of the condensed water in the water receiving groove 611 and prevent the condensed water from staying in the water receiving groove 611 for too long. The condensed water is discharged through the drainage portion 62. The water receiving tray 60 of the embodiment of the present application can achieve a good water collection and diversion effect, avoiding the accumulation of condensed water in the water receiving tray 60 that will breed bacteria and even cause corrosion to the water receiving tray 60.

[0135] Please refer to Figure 9 and Figure 10 , in some embodiments, a water storage groove 621 structure, a drain pipe 622, and a water pump mounting block 623 are provided in the drainage portion 62. Among them, the drain pipe 622 is located in the water storage groove 621. After the water in the water receiving groove 611 flows to the drainage portion 62, the water in the drainage portion 62 all flows into the water storage groove 621, thereby improving the drainage efficiency of the drain pipe 622. The water pump mounting block 623 can facilitate the installation and fixation of the water pump on the drainage portion 62.

[0136] Such as Figure 9 and Figure 10As shown, the second housing 30 further includes a pipe routing portion 39. The pipe routing portion 39 connects the drainage portion 62 and one end of the housing main body 311 in the length direction, and includes a first connecting plate 391 that connects the drainage portion 62 and the side portion of the housing main body 311 and is horizontally arranged, and a second connecting plate 392 that is provided on the first connecting plate 391 and is vertically arranged. The first connecting plate 391 is provided with a through hole 393. The second connecting plate 392 is located on one side of the through hole 393 and at the end far from the water receiving tray 60, and the second connecting plate 392 is connected to the side portion of the housing main body 311. The through hole 393 is used for the refrigerant pipe 921 of the heat exchanger 92 to pass through, facilitating the connection of the refrigerant pipe 921 of the heat exchanger 92 to the outdoor unit. The through hole 393 can be a long hole, so that the position of the refrigerant pipe 921 can be easily adjusted, and the installation operation of refrigerant pipes 921 of different sizes is also facilitated. During installation, the end of the first connecting plate 391 close to the air inlet cavity 11 forms a horizontal bearing portion, and the end of the second connecting plate 392 close to the air inlet cavity 11 forms an abutting portion. The side enclosure plate 70 is relatively fixed on the horizontal bearing portion and the abutting portion, which not only facilitates the installation and fixation of the second housing 30 and the side enclosure plate 70, but also facilitates fixation during installation. Among them, the pipe routing portion 39, the housing main body 311, and the drainage portion 62 are integrally formed structures, effectively improving the production efficiency and assembly efficiency, greatly reducing the number of parts, and reducing the logistics cost.

[0137] Please refer to again Figure 7 , the transverse flow area size of the pre-heat exchange cavity 132 gradually decreases in the direction from the overlapping boss 612 to the air outlet 15 (from back to front). Specifically, along the direction close to the air outlet 15, it can be that the horizontal height of the bottom wall 60a of the water receiving tray 60 gradually increases, or the horizontal height of the top wall of the heat exchange cavity 13 gradually decreases, or both, so that the gas flow area gradually decreases. For example, in one embodiment, the bottom wall of the pre-heat exchange cavity 132 is arranged in an arc shape, and the bottom wall of the pre-heat exchange cavity 132 extends upward in the direction from the overlapping boss 612 to the air outlet 15. The arc structure has less resistance to the air flow, better flow guiding effect, and can also reduce noise. Of course, in other embodiments, the bottom wall of the pre-heat exchange cavity 132 can also be arranged in an inclined plane. In this way, first, the conversion of partial static pressure to dynamic pressure can be realized, improving the wind speed and air outlet efficiency at the air outlet 15; second, the increase in the horizontal height of the bottom wall of the pre-heat exchange cavity 132 can prevent the air flow from blowing the water out of the heat exchange cavity 13 and avoid water droplets falling indoors, affecting the user experience.

[0138] The air outlet 15 can be arranged opposite to the heat exchanger 92, so that the airflow can flow to the air outlet 15 in a shorter path after passing through the heat exchanger 92, so as to reduce the loss of the airflow during the flow process. In some embodiments, the air outlet 15 can be formed by the first shell 20 (the upper shell 23 of the heat exchange chamber and the side panel 70) and the second shell 30 (the water receiving tray 60), and the direction of the air outlet 15 is horizontal. In general, the gas flows from the diffusion chamber 12 to the heat exchange chamber 13 and passes through the heat exchanger 92 in a roughly horizontal direction. The horizontal air outlet can make the airflow be discharged more directly after the heat exchange with the heat exchanger 92, making the gas flow more stable, reducing unnecessary airflow disturbances and noise, and improving the working efficiency and comfort of the system. In other embodiments, in some installation environments, the demand for side air outlet cannot be met, so the direction of the air outlet 15 can also be set upward or downward. For example, by using a variety of different installation accessories and interfaces, the direction of the air outlet 15 can be flexibly adjusted to meet the actual needs of different users or different scenarios, fully meet the personalized needs of users, and expand the application scope of the embodiments of the present application, thereby improving the applicability, stability and reliability of the entire system.

[0139] The first shell 20 and the second shell 30 can be formed by splicing multiple panels. However, if the panels are improperly installed, the sealing ring is aged or damaged, gaps may exist. When gas flows through the gaps, gas leakage will occur, which will cause a certain loss of energy of the airflow and may also generate noise or abnormal sound, increasing subsequent maintenance costs. In addition, the installation process is complicated and the production efficiency is low.

[0140] In some embodiments, the pressure diffuser upper shell 22 and the heat exchange chamber upper shell 23 are an integral structure, or the shell body 311 and the water receiving tray 60 are an integrally formed component, or the pressure diffuser upper shell 22 and the heat exchange chamber upper shell 23 are an integral structure and the shell body 311 and the water receiving tray 60 are an integrally formed component. For example, the second shell 30 can be integrally formed by plastic injection molding. The plastic material is light in weight, which can reduce the weight of the product and facilitate transportation and installation. In the embodiment of the present application, the number of parts of the first shell 20 and / or the second shell 30 is reduced, the manufacturing process is simple, suitable for commercial production, and can effectively improve production efficiency and installation efficiency, and reduce costs.

[0141] In addition, the embodiments of the present application greatly reduce the situation of splicing multiple shell panels, thereby reducing the situation of gaps at the joints. The inner walls of the pressure diffuser chamber 12 and the heat exchange chamber 13 have higher integrity, the leakage amount during the airflow process is greatly reduced, the static pressure loss is also reduced, and the airflow is transmitted more smoothly, thereby increasing the air supply and heat exchange efficiency, and reducing the generation of noise.

[0142] In summary, the design of integrally molding the diffuser chamber upper shell 22 and the heat exchange chamber upper shell 23, and integrally molding the shell main body 311 and the water receiving tray 60 not only reduces the number of components but also simplifies the complexity in the assembly process. This integrally molded structure can improve the overall stability and durability. Secondly, the integrally molded inner walls of the diffuser chamber 12 and the heat exchange chamber 13 can also provide a more uniform air flow distribution. Compared with a housing structure composed of multiple spliced plates, the integrally molded design can eliminate the unevenness at the splicing points, ensure smoother air flow in the air duct, reduce energy loss and pressure loss. In addition, since the chamber walls are manufactured by one-time molding without splicing points, the possibility of air leakage can be effectively reduced. This optimized sealing performance can not only improve the working efficiency of the system but also help prevent irrelevant gases or foreign objects from entering the air duct, protecting the safe and stable operation of the heat exchange chamber 13. Generally speaking, based on the design concept of integral molding, the embodiment of the present application optimizes the connection structure between the diffuser chamber 12 and the heat exchange chamber 13, which not only simplifies the manufacturing and assembly processes but also improves the stability, durability and overall working efficiency of the system.

[0143] Further, please refer to Figure 4 and Figure 6 again. In one embodiment, the diffuser chamber upper shell 22, the heat exchange chamber upper shell 23 and the air inlet chamber upper shell 21 are integrally molded components. This embodiment of the present application not only further reduces the number of housing components, simplifies the manufacturing and assembly processes, but also further reduces the splicing points of the housing, making the air flow smoother and reducing energy loss and pressure loss. More importantly, the air inlet chamber 11, the diffuser chamber 12 and the heat exchange chamber 13 enclosed by such an integrated cover 20a (including the diffuser chamber upper shell 22, the heat exchange chamber upper shell 23, the air inlet chamber upper shell 21 and the air inlet chamber rear shell 26) and the second housing 30 form a coherent air duct, which can improve the pressure resistance of the air duct system. Specifically, when the fan 91 is a cross-flow fan 91, the fan 91 does not need to be provided with an additional volute. The first housing 20 and the second housing 30 can not only act as the outer shell but also, through adaptive design on the inner wall, act as the volute of the cross-flow fan 91. In this way, the indoor unit 1 integrates the volute and the outer shell into one structure, reducing the number of structures of the air duct assembly 10 and shrinking the volume of the air duct assembly 10, which is beneficial to the miniaturization of the indoor unit 1 to adapt to more usage environments with relatively compact installation spaces.

[0144] Of course, in other embodiments, the indoor unit 1 may further include an outer shell, which can be configured to cover the outer surfaces of the first housing 20 and the second housing 30, only exposing the air outlet 15 and the air suction port 14 to communicate with the outside, so as to play a role in protecting the housing.

[0145] Please refer to Figure 13, in some embodiments, the housing further includes a thermal insulation layer 80, specifically including an upper thermal insulation layer 81 and a lower thermal insulation layer 82. The upper thermal insulation layer 81 is disposed on the surface of the upper housing 23 of the heat exchange chamber facing the interior of the heat exchange chamber 13, and the lower thermal insulation layer 82 is disposed on the outer surface of the water receiving tray 60. To protect the lower thermal insulation layer 82, the housing further includes a sheet metal part 83 disposed outside the water receiving tray 60 by means of bolt connection or the like, and the lower thermal insulation layer 82 is clamped between the sheet metal part 83 and the water receiving tray 60. The thermal insulation layer 80 can be thermal insulation sponge, foam part or thermal insulation glue. Thus, by providing the thermal insulation layer 80, it can maintain the temperature inside the air duct assembly 10 to a certain extent, reduce the probability of the energy inside the indoor unit 1 being dissipated outward through the first housing 20 and the second housing 30, effectively isolate external noise and abnormal sounds, and play a damping role in the propagation of internal noise. Furthermore, it can protect the internal components from external noise interference and improve the stability and reliability of the entire system.

[0146] Further, as Figure 7 shown, the indoor unit 1 can be an air duct machine, and has an air duct air inlet interface 101 and an air duct air outlet interface 102. The air duct air inlet interface 101 is defined between the rear side of the heat exchange chamber 13 and the rear side of the air inlet chamber 11, and the air duct air outlet interface 102 is defined by the air outlet 15. Thus, there are positions on the indoor unit 1 for connecting the air inlet duct and the air outlet duct, which facilitates the installation of the indoor unit 1 provided in this application.

[0147] Optionally, both the air duct air inlet interface 101 and the air duct air outlet interface 102 are formed by the connection edges connected to the air duct assembly 10. In this way, the air duct air inlet interface 101 can be connected opposite to the pipe orifice of the air inlet duct, and the air duct air outlet structure can be connected opposite to the pipe orifice of the air outlet duct, which facilitates connecting the air inlet duct and the air outlet duct to the indoor unit 1.

[0148] To further improve the noise of the air flow, in some embodiments of this aspect, the present application embodiment also specifically makes relevant improvements to the volute tongue 40. The following combines the attached Figures 14 to 20 , and makes relevant explanatory descriptions on the detailed structure at the volute tongue 40.

[0149] Please refer to Figures 14 to 16 , in some embodiments, the second housing 30 includes a first split structure 31 and a second split structure 32. Among them, the first split structure 31 includes a water receiving tray, a housing main body 311, and a support part 312 disposed at one end of the housing main body 311 away from the water receiving tray. The second split structure 32 is connected to the support part 312 to jointly cooperate with the support part 312 and the housing main body 311 to define the bottom wall of the diffuser chamber 12, and a part of the second split structure 32 constitutes the volute tongue 40.

[0150] In some embodiments, the volute tongue 40 can guide the air flow coming out of the fan into the diffuser chamber 12, that is, it is used to guide the air flow in the air inlet chamber 11 into the diffuser chamber 12. The volute tongue 40 includes a volute tongue main body 41 and a guide rib 42.

[0151] The volute tongue main body 41 is the main structure of the volute tongue 40 and can be made of plastic material to be manufactured by injection molding. Of course, the volute tongue main body 41 can also be made of metal material, and the present application does not limit this. The volute tongue main body 41 has a main body surface 411. The main body surface 411 of the volute tongue main body 41 is configured as a first windward section 412 and a first air guiding section 413 that are adjacent in sequence. When projected along the length direction of the air duct assembly 10, the contour line of the first windward section 412 is connected to the profile line of the air inlet chamber 11. The first air guiding section 413 has a first arc contour line 414. The bottom wall of the diffuser chamber 12 is configured as a diffuser section 121. The profile line of the diffuser section 121 is set in a straight line and has a first straight contour line 1211. The first arc contour line 414 overlaps with the starting point of the first straight contour line 1211.

[0152] A plurality of guide ribs 42 are convexly provided on the main body surface 411 of the volute tongue main body 41 at intervals along the length direction of the air duct assembly 10. Each guide rib 42 is configured as a second windward section 423 and a second air guiding section 424. The second windward section 423 is arranged on the first windward section 412, and the second air guiding section 424 is arranged on the first air guiding section 413. When projected along the length direction of the air duct assembly 10, the end point of the contour line of the second air guiding section 424 does not exceed the starting point of the first straight contour line 1211.

[0153] In summary, the volute tongue 40 of this embodiment has at least two aspects of effects:

[0154] First, since the air flow blown out by the fan has a relatively high flow rate during operation, it is easy to generate noise. Based on this, in the present application, a plurality of guide ribs 42 are convexly provided on the main body surface 411 at intervals, so that when the air flow blown out by the fan flows through the volute tongue main body 41 and is guided by the main body surface 411, part of the air flow flows between two adjacent guide ribs 42. In this way, the noisy air flow will be separated, so that the energy of the noise can be weakened, reducing the impact of the noise on the user and reducing the generation of noise, thereby improving the use experience. In addition, the plurality of guide ribs 42 are arranged at intervals along the length direction of the air duct assembly 10. In this way, under the guiding action of the plurality of guide ribs 42, the flow of the air flow in the length direction of the air duct assembly 10 can be reduced, that is, the flow of the air flow in the axial direction of the fan can be reduced, so as to reduce the energy loss of the air flow during the flow to the air outlet 15;

[0155] Second, on the basis that the contour line end point of the second air guiding section 424 of the air guiding rib 42 in this embodiment does not exceed the starting point of the first straight contour line 1211, compared with the form in which the contour line end point of the second air guiding section 424 of the air guiding rib 42 overlaps with the contour line starting point of the diffuser section 121, on the one hand, when the ends of the plurality of air guiding ribs 42 in this embodiment do not extend to the diffuser section 121, the plurality of air guiding ribs 42 will not occupy the space of the diffuser cavity 12, thereby avoiding the reduction of the air flow space for the air flow in the diffuser cavity 12, and further avoiding the reduction of the air volume of the air flow flowing through the diffuser cavity 12 to ensure the air output; on the other hand, compared with the form in which the contour line end point of the second air guiding section 424 of the air guiding rib 42 overlaps with the contour line starting point of the diffuser section 121, it can also reduce the extension length of each air guiding rib 42, thereby reducing the material consumption of the air guiding rib 42 and reducing the production cost of the volute tongue 40.

[0156] Please refer to Figure 16 , in some embodiments, the first straight contour line 1211 is tangent to the first arc contour line 414. It can be understood that when the air flow flows through the main body surface 411, part of it will flow towards the diffuser section 121 under the guidance of the first air guiding section 413. If the first straight contour line 1211 is not tangent to the arc contour line of the first air guiding section 413, there will be a groove at the connection between the first straight contour line 1211 and the first arc contour line 414. Therefore, on the basis that the first straight contour line 1211 is tangent to the first arc contour line 414, it can ensure that the air flow guided by the first air guiding section 413 smoothly flows towards the diffuser section 121, thereby further reducing the noise generated when the air flow flows.

[0157] Please continue to refer to Figure 16 , further, the second air guiding section 424 has a second arc contour line 425 and a second straight contour line 426. The first arc contour line 414 and the second arc contour line 425 are correspondingly arranged. The second straight contour line 426 extends from the end point of the second arc contour line 425 and terminates at the end point of the first arc contour line 414.

[0158] In this way, the air flow will pass through the area of the second arc contour line 425 of the second air guiding section 424, and then pass through the area of the second straight contour line 426 of the second air guiding section 424. Based on the setting that the second straight contour line 426 terminates at the end point of the first arc contour line 414, when the air flow flows out of the second air guiding section 424, it will continue to flow through the area of the first arc contour line 414 of the first air guiding section 413 and finally flow towards the diffuser section 121, thereby ensuring that the air guiding rib 42 does not occupy the space of the diffuser cavity 12, avoiding the reduction of the air volume of the air flow flowing through the diffuser cavity 12 to ensure the air output, and reducing the extension length of each air guiding rib 42, thereby reducing the material consumption of the air guiding rib 42 and reducing the production cost of the volute tongue 40.

[0159] Please refer to Figure 16 , in some embodiments, both the first windward section 412 and the first air guiding section 413 are arranged with an arc-shaped contour line. The normal vector direction of the arc apex of the first windward section 412 is away from the air inlet cavity 11, and the normal vector direction of the arc apex of the first air guiding section 413 is towards the air inlet cavity 11.

[0160] In this way, when the fan is working, part of the air flow sent by it will flow towards the diffuser cavity 12 under the guidance of the first air guiding section 413, while part will return to the air inlet cavity 11 under the guidance of the first windward section 412. Thus, this part of the air flow can flow towards the fan to play a role in stabilizing the eccentric vortex of the fan, and further improve the air supply performance of the fan. On the basis of the improved air supply performance of the fan, the power of the fan can be appropriately reduced when the required air supply volume is reached, thereby reducing the noise generated during the operation of the fan.

[0161] Please continue to refer to Figure 16 , further, the second windward section 423 is arranged with an arc-shaped contour line. The second air guiding section 424 has a second arc-shaped contour line 425 and a second straight contour line 426. The first arc-shaped contour line 414 and the second arc-shaped contour line 425 are correspondingly arranged. The first arc-shaped contour line 414 corresponds to the second arc-shaped contour line 425. The second straight contour line 426 starts from the end point of the second arc-shaped contour line 425 and ends at the end point of the first arc-shaped contour line 414.

[0162] In this way, the air flow will pass through the area of the second arc-shaped contour line 425 of the second air guiding section 424, and then through the second straight contour line 426 of the second air guiding section 424. On the basis that the second straight contour line 426 of the second air guiding section 424 ends at the end point of the second arc-shaped contour line 425, when the air flow flows out of the second air guiding section 424, it will continue to flow through the area of the first arc-shaped contour line 414 of the first air guiding section 413, and finally flow towards the diffuser section 121. Thus, it can be ensured that the flow guiding rib 42 does not occupy the space of the diffuser cavity 12, avoiding the reduction of the air volume of the air flow passing through the diffuser cavity 12, ensuring the air output volume, and reducing the extension length of each flow guiding rib 42, thereby reducing the material consumption of the flow guiding rib 42 and lowering the production cost of the volute tongue 40.

[0163] Please refer to Figure 16 , in some embodiments, an inner wall of the air inlet cavity 11 is provided with a concave cavity 45. The concave cavity 45 is adjacent to the first windward section 412 and is located upstream of the first windward section 412. Thus, the concave cavity 45 can separate the inner wall of the air inlet cavity 11 from the first windward section 412, thereby achieving the effect of reducing noise.

[0164] Please refer to in combination Figures 16 to 18, in some embodiments, a flow guiding groove 43 is jointly defined between two adjacent flow guiding ribs 42 and the main body surface 411. Among them, the cross-sectional shape of the flow guiding groove 43 can be trapezoidal, rectangular, triangular or other shapes, and this embodiment does not limit this.

[0165] Projecting along the length direction of the air duct assembly 10, a part of the first windward section 412 and the first air guiding section 413 at the bottom of the flow guiding groove 43 constitutes a bottom profile line 431 of the flow guiding groove 43. The end point of the contour line of the second air guiding section 424 intersects with the bottom profile line 431, that is, the end of the bottom profile line 431 does not exceed the starting point of the first straight contour line 1211. In this way, the air flow blown by the fan, under the guidance of the flow guiding groove 43, will flow to the first air guiding section 413 and then to the diffuser section 121, so as to ensure that the flow guiding ribs 42 do not occupy the space of the diffuser cavity 12, avoid reducing the air volume of the air flow flowing through the diffuser cavity 12, ensure the air output, and reduce the extension length of each flow guiding rib 42, thereby reducing the material consumption of the flow guiding rib 42 and reducing the production cost of the volute tongue 40.

[0166] Please continue to refer to Figures 16 to 18 , further, the diffuser section 121 is connected to the first air guiding section 413 and forms an intersection line 46 at the connection. Among them, the end point of the bottom profile line 431 does not exceed the intersection line 46. In this way, the air flow blown by the fan, under the guidance of the flow guiding groove 43, will not immediately flow to the diffuser section 121, but first flow to the first air guiding section 413 and then to the diffuser section 121, so as to ensure that the flow guiding ribs 42 do not occupy the space of the diffuser cavity 12, avoid reducing the air volume of the air flow flowing through the diffuser cavity 12, ensure the air output, and reduce the extension length of each flow guiding rib 42, thereby reducing the material consumption of the flow guiding rib 42 and reducing the production cost of the volute tongue 40.

[0167] Please refer to Figures 18 to 19 , in some embodiments, the shape of the contour line of the flow guiding rib 42 is configured to be wavy. When the profile line of the flow guiding rib 42 is configured to be wavy, it can be a three-section shape connected in sequence. The first section is an arc-shaped concave toward the volute tongue main body 41, the second section is an arc-shaped convex away from the volute tongue main body 41, and the third section is an arc-shaped concave toward the volute tongue main body 41. It can be understood that the first section is closer to the diffuser section 121 than the third section, and the curvature of the second section is greater than that of the first section. In this way, the first section will be smoother, so that when the air flow passes through the flow guiding rib 42, the wind resistance can be reduced, the loss of the air flow can be reduced, and the air supply capacity can be enhanced.

[0168] In some embodiments, the contour line of the flow guiding rib 42 is configured to be a broken line shape. When the profile line of the flow guiding rib 42 is configured to be a broken line shape, it may be a two-segment shape connected together. The first segment is connected to the lower part of the volute tongue body 41 and extends away from the volute tongue body 41 and is connected to the second segment. The second segment extends towards the volute tongue body 41 and intersects with the bottom profile line 431.

[0169] In some embodiments, the contour line of the flow guiding rib 42 is configured to be a single arc shape bulging away from the volute tongue body 41. When the profile line of the flow guiding rib 42 is configured to be a single arc shape bulging away from the volute tongue body 41, when the air flow passes through the flow guiding rib 42, the resistance encountered during the flow process is less, which can reduce the wind resistance and the loss of the air flow, so as to enhance the air supply capacity.

[0170] In some embodiments, a plurality of flow guiding ribs 42 are all located on one side of the diffuser section 121. It can be understood that a plurality of flow guiding ribs 42 can be located on the lower side of the diffuser section 121 in the vertical direction. In this way, under the guidance of the flow guiding ribs 42, the air flow will flow upward and towards the diffuser section 121 at this time.

[0171] Of course, in other structural forms, a plurality of flow guiding ribs 42 can also be located on the upper side of the diffuser section 121 in the vertical direction, and the present application does not limit this.

[0172] Please refer to Figures 19 to 20 , in some embodiments, the connection between the end of the second air guiding section 424 extending towards the diffuser section 121 and the first air guiding section 413 is in a smooth transition. In this way, when the air flow passes through the connection between the end of the second air guiding section 424 and the first air guiding section 413, the wind resistance is small, the flow is relatively smooth, and noise generation is avoided.

[0173] Alternatively, the connection between the end of the second windward section 423 extending towards the air inlet cavity 11 and the first windward section 412 is in a smooth transition. In this way, when the air flow passes through the connection between the end of the second windward section 423 extending towards the air inlet cavity 11 and the second air guiding section 424, the wind resistance is small, the flow is relatively smooth, and noise generation is avoided.

[0174] Alternatively, the connection between the end of the second air guiding section 424 extending towards the diffuser section 121 and the first air guiding section 413 is in a smooth transition, and the connection between the end of the second windward section 423 extending towards the air inlet cavity 11 and the first windward section 412 is in a smooth transition. In this way, when the air flow passes through the connection between the end of the second air guiding section 424 and the first air guiding section 413, the wind resistance is small, the flow is relatively smooth, and noise generation is avoided. Moreover, when the air flow passes through the connection between the end of the second windward section 423 extending towards the air inlet cavity 11 and the second air guiding section 424, the wind resistance is small, the flow is relatively smooth, and noise generation is avoided.

[0175] Furthermore, the housing main body 311 and the support portion 312 can be an integral structure. In this way, the connection firmness between the housing main body 311 and the support portion 312 can be improved, and the assembly steps of the housing main body 311 and the support portion 312 can be reduced, thereby improving production efficiency. Of course, they can also be a split structure and fixed by means such as gluing and snap connection. The present application does not limit this.

[0176] Please refer to Figure 19 , in some embodiments, the second split structure 32 includes a first plate segment 321, a second plate segment 322, and a third plate segment 323. The first plate segment 321 configures the volute tongue 40, and the second plate segment 322 and the third plate segment 323 are connected to opposite ends of the first plate segment 321. Among them, the second plate segment 322 and the housing main body 311 of the first split structure 31 cooperate to configure the bottom wall of the diffuser chamber 12, and the third plate segment 323 and the housing main body 311 of the first split structure 31 cooperate to configure a part of the inner wall of the air inlet chamber 11.

[0177] The support portion 312 is provided with a first connection portion 3121 and a second connection portion 3122. The first connection portion 3121 is disposed above the support portion 312, and the second connection portion 3122 is disposed below the support portion 312. Among them, the second plate segment 322 is snap-connected to the first connection portion 3121, and the third plate segment 323 is snap-connected to the second connection portion 3122.

[0178] The first plate segment 321, the second plate segment 322, and the third plate segment 323 are connected in a head-to-tail and sequentially connected form, and the three can be an integral structure, making their connection more firm and reducing the assembly steps. Of course, they can also be a split structure and fixed by means such as threaded connection, snap connection, or bonding. The present application does not limit this.

[0179] Specifically, the first connection portion 3121 can be a first snap, and a snap hole for the first snap to be snap-connected is formed on the second plate segment 322, realizing the snap connection between the second plate segment 322 and the first connection portion 3121; further, the first snap can be trapezoidal, that is, the side surface of the first snap will form a guiding surface to guide and cooperate with the hole side wall of the snap hole when the first snap penetrates the snap hole, facilitating assembly.

[0180] The second connection portion 3122 can be a second snap, and a third snap is disposed on the third plate segment 323. A snap space is formed by enclosing the second snap, so that when the third snap overlaps on the second snap, it can be snap-connected in the snap space. In this way, in the up-and-down direction, there are at least two snap connection points between the support portion 312 and the second split structure 32, so that the connection between the support portion 312 and the second split structure 32 is more stable, and the disassembly and assembly operations are more convenient and fast.

[0181] Please refer to Figure 16 , further, a lapping step is formed by the supporting part 312 being recessed in a direction away from the second split structure 32. The first connecting part 3121 is arranged on the lapping step. The second plate segment 322 can be lapped on the lapping step and is snap-connected with the first connecting part 3121. In this way, compared with the lapping step, the second plate segment 322 will be closer to the diffuser upper shell 22, so that the air flow blown by the fan will not flow to the lapping step, avoiding that in long-term use, the supporting part 312 warps in the direction towards the diffuser upper shell 22 under the long-term blowing of the air flow. This will cause the air flow to be blocked by the warped supporting part 312 and consume the energy of the air flow. And the setting of the lapping step in this embodiment makes the lapping part of the second plate segment 322 and the lapping step deviate from the flowing direction of the air flow. In this way, even in long-term use, the air flow will not blow the second plate segment 322 to warp, and the possibility of consuming the energy of the air flow can be reduced.

[0182] Please continue to refer to Figure 16 , in some embodiments, a hollow cavity 16 is formed by enclosing the second split structure 32 and the supporting part 312. It can be understood that the hollow cavity 16 can include a first half cavity and a second half cavity. The first half cavity is enclosed by the inner wall surface of the second split structure 32 being recessed, and the second half cavity is enclosed by the outer wall surface of the supporting part 312 being recessed, so as to enclose the hollow cavity 16 in this way; of course, it can also be that the hollow cavity 16 is enclosed only by the inner wall surface of the second split structure 32 being recessed, or the hollow cavity 16 is enclosed by the outer wall surface of the supporting part 312 being recessed. The present application does not limit this. In this way, compared with the form that the second split structure 32 and the supporting part 312 are non-hollow, this embodiment can reduce the materials of the volute tongue main body 41 and the supporting part 312, reduce the cost of the second housing 30, and can reduce the weight of the second housing 30, so that the overall weight of the indoor unit 1 is reduced.

[0183] The above part is the explanatory description of the structural improvement at the volute tongue 40 of the embodiment of the present application. Through the above settings, the air flow noise can be effectively improved and the air flow stability can be enhanced. The function of the volute tongue 40 is to divide the air flow and stabilize the eccentric vortex near the volute tongue 40. The existence of the eccentric vortex will affect the cross-flow area to a certain extent and affect the operating efficiency of the fan 91. Therefore, the following improvements are also made in the embodiment of the present application.

[0184] Refer to Figure 21 and Figure 22, in order to improve the gas flow performance during the use of the indoor unit 1, a first opening 37 is formed by opening on the first surface 34 of the cavity bottom surface of the diffuser cavity 12 formed by the second housing 30, and a second opening 38 is formed by opening on the second surface 35 of a partial cavity wall surface forming the air inlet cavity 11. At the same time, a return channel 36 is provided at the second housing 30, and the return channel 36 extends from the first opening 37 to the second opening 38.

[0185] In this way, the air flow driven by the fan 91 is split by the volute tongue 40 to flow to the diffuser cavity 12 and the side of the volute tongue 40 close to the air inlet side of the fan 91 respectively. After splitting, the air pressure in the diffuser cavity 12 becomes larger, so that the air pressure at the first opening 37 is greater than the air pressure at the second opening 38. Then, due to the pressure difference between the first opening 37 and the second opening 38, part of the air flow entering the diffuser cavity 12 is actively guided back to the air inlet side of the volute tongue 40 close to the fan 91 through the return channel 36 to do work again. It can not only make up for the pressure on the side of the fan 91 close to the volute tongue 40, thereby weakening the eddy current caused by the pressure difference, effectively improving the operating efficiency of the fan 91, improving the air intake efficiency and anti-pressure performance of the air inlet side of the fan 91, thus enhancing the overall aerodynamic performance of the air duct assembly 10. At the same time, after weakening the eddy current, the aerodynamic noise in the air duct assembly 10 can also be reduced synchronously to improve the user experience. And because the air pressure at the diffuser cavity 12 is greater than the air pressure of the volute tongue 40, so compared with the scheme of setting the first opening 37 at the volute tongue 40, the pressure difference between the first opening 37 and the second opening 38 in this application will also be greater than the scheme of setting the first opening 37 at the volute tongue 40. Furthermore, the efficiency of the air flow passing through the return channel 36 can be further improved to improve the effect of air supplement and pressure boost.

[0186] In some structural forms, the return channel 36 is arranged in a curve. Among them, the return channel 36 can be arranged in a curve such as an arc or a wavy line. In this way, the impact speed of the air flow in the return channel 36 can be slowed down to further reduce the air flow noise and stabilize the air flow. It should be noted that the return channel 36 can also be arranged in a straight line in other embodiments. In this way, at the same fan 91 rotation speed, the air volume is increased. Or the return channel 36 can also be a combination of a straight line and a curve extension, which can be specifically selected by those skilled in the art according to needs.

[0187] Optionally, the width dimension of the return channel 36 remains unchanged from the first opening 37 to the second opening 38, so as to maintain a stable flow of the air current when passing through the return channel 36, and further stably maintain the flow rate of the air current passing through the return channel 36, so as to improve the effect of supplementing air and increasing pressure on one side of the fan 91 close to the volute tongue 40. Or in another embodiment, the return channel 36 is arranged to gradually expand from the first opening 37 to the second opening 38. That is, the vertical distance between two relatively arranged surfaces of the return channel 36 is the width of the return channel 36, and the variation of the width of the return channel 36 gradually increases from the first opening 37 to the second opening 38. With such a setting, the variation of the width of the return channel 36 is relatively small at the first opening 37 at the beginning, so that the air current is evenly mixed during the process of entering the return channel 36. After that, the variation of the width of the return channel 36 continuously increases, and on the premise of ensuring that there is no flow separation in the return channel 36, the variation of the width with the same channel length is as large as possible, which can ensure the air current flow rate while reducing the air current speed, so as to achieve the purpose of reducing noise.

[0188] Referring to Figure 23 , in some embodiments, the extension line L0 of the orientation of the return channel 36 at the return outlet passes through the impeller of the fan 91, and the included angle between the extension line L0 and the outer peripheral tangent line L1 of the impeller of the fan 91 is θ, where θ is less than or equal to 15 degrees and greater than or equal to 0 degrees. In this way, while ensuring the stabilizing effect of the air current on the eccentric vortex of the impeller of the fan 91, it can avoid the air current having too strong an impact on the impeller of the fan 91 and causing noise. When θ is greater than 15 degrees, it will cause the air current to have too strong an impact on the impeller of the fan 91, and further cause the fan 91 to vibrate and generate noise. When θ is less than 0 degrees, it will cause the supplementary effect of the air current on the impeller of the fan 91, that is, the effect of stabilizing the eccentric vortex of the impeller of the fan 91 by the air current is poor. Exemplarily, θ can be 0 degrees, 2 degrees, 5 degrees, 7 degrees, 10 degrees, 12 degrees or 15 degrees, etc., and the embodiments of the present application do not limit this.

[0189] Furthermore, θ is equal to 0 degrees. In this way, the extension line L0 of the orientation of the return channel 36 at the second opening 38 coincides with the outer peripheral tangent line L1 of the fan 91, so that the air current flowing out through the second opening 38 can both play a stabilizing effect on the eccentric vortex of the fan 91 and avoid the air current from impacting the fan 91 and preventing noise generation.

[0190] In some embodiments, with reference to Figure 23, the return air channel 36 passes through the outside of the impeller of the blower 91 along the extension line L0 of the orientation of the second opening 38, and the included angle with the outer peripheral tangent line L1 of the impeller of the blower 91 is β, and β is less than or equal to 45 degrees and greater than or equal to 0 degrees. In this way, while ensuring the stabilizing effect of the air flow on the eccentric vortex of the impeller of the blower 91, it can avoid the too strong impact of the air flow on the impeller of the blower 91 and cause noise. When β is less than 0 degrees, it will cause the too strong impact of the air flow on the impeller of the blower 91, and then cause the impeller of the blower 91 to vibrate and generate noise. When θ is greater than 45 degrees, it will cause the supplementary effect of the air flow on the impeller of the blower 91, that is, the effect of stabilizing the eccentric vortex of the impeller of the blower 91 by the air flow is poor. Exemplarily, β can be 0 degrees, 10 degrees, 20 degrees, 30 degrees, 40 degrees, 45 degrees, etc., and the embodiments of the present application do not limit this.

[0191] Further, β is equal to 0 degrees. In this way, the return air channel 36 coincides with the outer peripheral tangent line L1 of the impeller of the blower 91 along the extension line L0 of the orientation of the second opening 38, so that the air flow flowing out through the second opening 38 can both have a stabilizing effect on the eccentric vortex of the impeller of the blower 91 and avoid the impact of the air flow on the blower 91 and prevent noise generation.

[0192] In some structural forms, the second housing 30 further includes a connecting surface (not shown) connected between the first surface 34 and the second surface 35. The connecting surface is recessed to form an air flow groove. One end of the air flow groove penetrates through the first surface 34 to communicate with the first opening 37, and the other end of the air flow groove penetrates through the second surface 35 to communicate with the second opening 38. The volute tongue 40 covers the connecting surface so that the air flow groove forms the return air channel 36. In this way, by setting the air flow groove on the connecting surface to form the return air channel 36, the process difficulty is low and it is convenient for processing. At the same time, when maintenance personnel need to clean and maintain the inside of the return air channel 36 later, after removing the volute tongue 40, the connecting surface is exposed, so that the air flow groove forming the return air channel 36 can be directly cleaned and maintained, and then it is convenient to regularly clean the return air channel 36 to ensure the smoothness of the return air channel 36.

[0193] Refer to Figure 22 and Figure 23, in some structural forms, the second housing 30 further includes a housing body 311, a support portion 312, and a flow guide member 50. The housing body 311 is provided with a first surface 34, and the first surface 34 constituting the bottom surface of the diffuser chamber 12 is used to guide the air flow to the heat exchange chamber 13. The housing body 311 is connected to the volute tongue 40, and the support portion 312 is connected to the side of the housing body 311 facing away from the first surface 34 and is connected to the volute tongue 40. In this way, the volute tongue 40 is connected by both the housing body 311 and the support portion 312 to improve the position stability of the volute tongue 40 after connection. The flow guide member 50 is connected to the side of the housing body 311 facing away from the first surface 34, and the flow guide member 50 and the support portion 312 cooperate to form a second opening 38.

[0194] The side of the support portion 312 facing away from the volute tongue 40 is configured as a first air return surface. And it is spaced from the support portion 312. The side of the flow guide member 50 facing the support portion 312 is configured as a second air return surface 521. A return air passage 36 is formed by the cooperation between the second air return surface 521 and the first air return surface. In this way, the return air passage 36 is formed by the cooperation between the support portion 312 and the flow guide member 50, that is, a split structure design is adopted to form the return air passage 36 and the second opening 38. In this way, it is convenient to disassemble and control to change the shape of the return air passage 36, and it is easier to control the orientation of the second opening 38.

[0195] With reference to Figures 24 to 26 , further, in order to reduce the deformation of the flow guide member 50 and the support portion 312 when the air flow passes through the return air passage 36, at least one flow guide rib 55 is provided on one of the first air return surface and the second air return surface 521, and the other of the first air return surface and the second air return surface 521 abuts against at least one flow guide rib 55. In this way, the flow guide rib 55 can provide support for the flow guide member 50 and the support portion 312, and further improve the deformation at the flow guide member 50 and the support portion 312.

[0196] Furthermore, the flow guide rib 55 protrudes from the first air return surface and is integrally formed with the first air return surface, and the second air return surface 521 abuts against the flow guide rib 55. Or, in another embodiment, the flow guide rib 55 protrudes from the second air return surface 521 and is integrally formed with the second air return surface 521, and the first air return surface abuts against the flow guide rib 55. In this way, the flow guide rib 55 is integrally provided with one of the first air return surface and the second air return surface 521 and abuts against the other. The attachment area of the flow guide rib 55 is larger, the structural stability is stronger, the interaction force among the flow guide rib 55, the flow guide member 50, and the support portion 312 is stronger, and it is less likely to deform.

[0197] Optionally, one of the first air return surface and the second air return surface 521 is provided with a plurality of flow guiding ribs 55. The plurality of flow guiding ribs 55 are arranged side by side and at intervals along the transverse direction of the return channel 36. The plurality of flow guiding ribs 55 divide the first opening 37 into a plurality of sub-inlets. The transverse direction of the return channel 36 is perpendicular to the direction of the airflow in the return channel 36 and perpendicular to the direction of the first air return surface facing the second air return surface 521. Referring to the figure, the direction indicated by the arrow T is the transverse direction of the return channel 36. In this way, by providing a plurality of flow guiding ribs 55, the structural stability of the flow guiding member 50 and the supporting portion 312 is further improved. At the same time, the first opening 37 is divided into a plurality of sub-inlets by the plurality of flow guiding ribs 55, and the return channel 36 is divided into a plurality of sub-air ducts. The airflow separated from the diffuser cavity 12 is separated into multiple airflows and led out of the diffuser cavity 12, and the pressure of the airflow entering the return channel 36 is divided. The airflow pressure entering a single sub-air duct is small, and the acting force of the airflow in each sub-air duct on the flow guiding member 50 and the supporting portion 312 is also small, reducing the impact on the flow guiding member 50 and the supporting portion 312, thereby further reducing the situation that the flow guiding member 50 and the supporting portion 312 are deformed due to the airflow entering the return air duct.

[0198] With reference to Figure 22 , Figure 27 and Figure 28 , further, the air duct assembly 10 further includes a plurality of clamping blocks. Each clamping block protrudes from the flow guiding rib 55 located on the first air return surface and is integrally formed with the flow guiding rib 55. The second air return surface 521 is provided with a plurality of clamping openings 522. Each clamping block is inserted into one of the clamping openings 522. In this way, during assembly, by inserting the clamping block into the corresponding clamping opening 522, the alignment of the flow guiding member 50 and the supporting portion 312 can be quickly completed, the assembly is convenient, the alignment stability of the flow guiding member 50 and the supporting portion 312 is effectively improved, and it can also effectively prevent the flow guiding member 50 and the supporting portion 312 from deforming when the wind pressure is too high.

[0199] Optionally, the flow guiding rib 55 extends along the longitudinal direction of the return channel 36 and from the first opening 37 to the side where the second opening 38 is located. The longitudinal direction of the return channel 36 is the direction of the airflow in the return channel 36. One of the first air return surface and the second air return surface 521 is provided with a plurality of flow guiding ribs 55. The plurality of flow guiding ribs 55 are arranged side by side and at intervals along the transverse direction of the return channel 36. The transverse direction of the return channel 36 is perpendicular to the direction of the airflow in the return channel 36 and perpendicular to the direction of the first air return surface facing the second air return surface 521. In this way, the flow guiding rib 55 penetrates through the return channel 36 along the longitudinal direction of the return channel 36, so that the state of the airflow flowing out of the return channel 36 is stable, and the wind resistance of the airflow flowing to the air inlet side of the fan 91 is reduced.

[0200] Furthermore, in the transverse direction of the return channel 36, the spacing between two adjacent flow guiding ribs 55 is equal, which is convenient for processing and ensures the overall force balance when the support portion 312 and the flow guiding member 50 are installed.

[0201] Of course, the spacing between two adjacent flow guiding ribs 55 may not be equal. It can be understood that in the transverse direction of the return channel 36, the air flow pressures in different regions of the return channel 36 may be different. In the region with a stronger air flow pressure, the acting force of the air flow on the support portion 312 and the flow guiding member 50 is stronger, and the support portion 312 and the flow guiding member 50 at this position are more likely to deform. Based on this, in the transverse direction of the return channel 36, the return channel 36 includes a plurality of return air regions arranged side by side, and the air flow pressures in two adjacent return air regions are different. The spacing between two adjacent flow guiding ribs 55 in the return air region with a larger air flow pressure is a, and the spacing between two adjacent flow guiding ribs 55 in the return air region with a smaller air flow pressure is a, where a > a. In this way, in the transverse direction of the return channel 36, when the air flow pressure in the middle region is larger and the air flow pressure in the edge region is smaller, in the direction from the edge region to the middle region, the spacing between two adjacent flow guiding ribs 55 gradually decreases, that is, the plurality of flow guiding ribs 55 are distributed in a state that is denser in the middle and looser at the edge.

[0202] Refer to Figure 27 , optionally, at least one flow guiding rib 55 provided on one of the first return air surface and the second return air surface 521 has two third surfaces 551 arranged oppositely, and the portions of the two third surfaces 551 facing the same side of one of the first return air surface and the second return air surface 521 protrude perpendicularly or at an obtuse angle. In this way, the flow guiding rib 55 has a larger connection area with the corresponding flow guiding member 50 and the support portion 312, improving the installation stability of the flow guiding rib 55.

[0203] Furthermore, the flow guiding rib 55 has a fourth surface 552 connected between the two third surfaces 551, and the fourth surface 552 abuts against the other of the first return air surface and the second return air surface 521. To improve the support stability of the flow guiding rib 55 for the support portion 312 and the flow guiding member 50. For example, when both of the two third surfaces 551 of the flow guiding rib 55 are connected to the first return air surface, the fourth surface 552 is attached to the second return air surface 521; when both of the two third surfaces 551 of the flow guiding rib 55 are connected to the second return air surface 521, the fourth surface 552 is attached to the first return air surface.

[0204] Optionally, in the direction where the first opening 37 of the return air channel 36 faces the second opening 38, the vertical distance between the two third surfaces 551 gradually decreases or remains unchanged. Considering that the air pressure at the first opening 37 is relatively high and the air pressure at the second opening 38 is relatively low, preferably, in the direction where the first opening 37 of the return air channel 36 faces the return air outlet, the vertical distance between the two third surfaces 551 in the transverse direction of the return air channel 36 gradually decreases, so that the flow area of the sub-air duct gradually increases.

[0205] Referring to Figure 22 and Figure 28 , in some structural forms, the deflector 50 includes a connecting portion 51, a deflecting portion 52, and a cavity wall portion 53. The connecting portion 51 is laminated on the side of the housing main body 311 facing away from the first surface 34 and is detachably mounted on the housing main body 311. Among them, the connecting portion 51 can be arranged as a flat plate and is laminated and attached to the housing main body 311, so as to increase the contact area between the two, thereby improving the connection stability. The deflecting portion 52 is angularly connected to the connecting portion 51 and has a second return air surface 521. The deflecting portion 52 is used to cooperate with the supporting portion 312 to form the return air channel 36 and the second opening 38. The deflecting portion 52 can be arranged as an arc-shaped plate, so as to facilitate guiding the flow direction of the air flow. The cavity wall portion 53 is angularly connected to one end of the deflecting portion 52 facing away from the connecting portion 51 and extends in the direction away from the housing main body 311. Thus, the cavity wall portion 53 is used to cooperate to form a part of the cavity wall of the air inlet cavity 11 (the front housing 33 of the air inlet cavity), so that the cavity wall portion 53 can also play a role in guiding the air flow to the fan 91. The connecting portion 51, the deflecting portion 52, and the cavity wall portion 53 can be an integral structure, so as to improve the overall structural stability of the deflector 50. Of course, the above three can also be separately arranged to facilitate the later maintenance and replacement of single components.

[0206] Furthermore, the connecting portion 51 has a first connection hole, the housing main body 311 has a second connection hole corresponding to the first connection hole, and the air duct assembly 10 further includes a fastener that sequentially passes through the second connection hole and the first connection hole to fix the connecting portion 51 to the housing main body 311. Among them, the first connection hole and the second connection hole can be threaded holes, and the fastener can be a screw. The connecting portion 51 is fixed to the housing main body 311 by using the screw. This fixing method is relatively simple in installation operation and easy to disassemble, which is convenient for subsequent maintenance.

[0207] The cross-flow fan 91 has advantages such as uniform air supply, simple structure, and convenient installation, but it also has disadvantages such as poor compressive resistance and high noise. In some duct systems with poor compressive resistance, the above-mentioned disadvantages of the cross-flow fan 91 are even more prominent. For this reason, in the design of the indoor unit 1 in the related art, a centrifugal fan 91 is often used to ensure the air supply distance. However, the centrifugal fan 91 has a relatively complex structure, is difficult to assemble, has a high maintenance cost, and also has a problem of high noise when the fan 91 operates at high speed. Combining Figure 7 , in some embodiments of the present application, thanks to the optimized design of the air duct at the connection between the diffuser chamber 12 and the heat exchange chamber 13, the noise reduction and flow guiding design of the volute tongue 40, and the related design of the return channel 36, the compressive resistance and gas flow performance of the air duct system are greatly enhanced, and at the same time, the noise can also be reduced. This undoubtedly can make up for the related defects of the indoor unit 1 and provide a structural condition for the indoor unit 1 to adopt the cross-flow fan 91. When the cross-flow fan 91 is applied to the indoor unit 1, it can not only ensure sufficient air supply distance and less noise impact, but also has the advantages of uniform air supply, simple structure, and convenient disassembly and maintenance. Further, when the cross-flow fan 91 is adopted, the upper shell 21 of the air inlet chamber can be directly integrally connected to the upper shell 22 of the diffuser chamber, the upper shell 23 of the heat exchange chamber, and the rear shell 26 of the air inlet chamber, and serve as a part of the housing of the indoor unit 1. In this way, the air inlet chamber 11, the diffuser chamber 12, and the heat exchange chamber 13 form a continuous air duct, and the cross-flow area in the air duct assembly 10 is more sufficient, which can further improve the compressive resistance of the air duct system and make the operation of the cross-flow fan 91 more ideal. In addition, the highly integrated housing structure is also beneficial to reducing the volume of the indoor unit 1 and improving the space utilization rate. It can be seen that in these embodiments, the structural designs of the cross-flow fan 91 and the air duct assembly 10 complement each other, and their synergistic effects can produce more prominent beneficial effects.

[0208] To solve the problems of high maintenance complexity and poor heat dissipation effect of the electric control box 93 in the related art, please refer to Figures 29 to 31 , in some embodiments, the electric control box 93 is arranged outside the air duct assembly 10, and part of the air suction port 14 is located between the electric control box 93 and the fan 91. In this way, when the electric control box 93 is exposed outside the air duct assembly, after removing the grille at the maintenance port, the electric control box 93 will be exposed, which is convenient for overhauling or disassembling and repairing the electric control box 93; moreover, when the fan 91 is running, the external air flow will be sucked to the electric control box 93, and the air flow will flow into the air inlet chamber 11 through the air suction port 14 after flowing through the electric control box 93. When the external air flow flows through the electric control box 93, it can carry the heat generated by the electric control box 93 and flow into the air inlet chamber 11 through the air suction port 14, so as to realize the heat dissipation of the electric control box 93 and make the use performance of the electric control box 93 better.

[0209] It should be noted that in some embodiments, since an external air suction port is usually provided on the ceiling below the second housing 30, in order to shorten the flow path of the external air flow to the electronic control box 93 and achieve efficient heat dissipation of the electronic control box 93, the electronic control box 93 can be arranged below the second housing 30. In this way, the air flow entering through the external air suction port can directly flow to the electronic control box 93.

[0210] Among them, the external air suction port is formed as a maintenance port of the indoor unit 1. It can be understood that a grille can be provided at the maintenance port. When performing maintenance or disassembly and repair on the electronic control box 93, the grille at the maintenance port needs to be removed, and then the electronic control box 93 can be maintained or disassembled and repaired.

[0211] Furthermore, during the operation of the indoor unit 1, external air flow needs to flow into the air inlet chamber 11. Therefore, the air suction port 14 includes a connected first air return port 141 and a second air return port 143. The first air return port 141 is arranged facing the external air suction port, and the second air return port 143 is located between the blower 91 and the electronic control box 93. In this way, during the operation of the motor, not only can the external air flow be sucked into the air inlet chamber 11 through the first air return port 141, but also the air flow after dissipating heat from the electronic control box 93 can be sucked into the air inlet chamber 11 through the second air return port 143, effectively dissipating heat from the electronic control box 93 while enabling the normal operation of the indoor unit 1.

[0212] In this embodiment, in order to shorten the flow path of the air flow and reduce the setting of pipelines, the first air return port 141 faces the lower part of the indoor unit 1; when the first air return port 141 faces the lower part of the indoor unit 1, the second air return port 143 can be located at the front side of the air suction port 14 or at the rear side of the first air return port 141. Here, no specific restrictions are imposed on the positional relationship between the first air return port 141 and the second air return port 143.

[0213] When the indoor unit 1 provided in this embodiment is installed in an indoor space, its height direction, length direction, and width direction are naturally formed. Among them, the height direction of the indoor unit 1 is consistent with the up-down direction ZZ in the figure, the length direction of the indoor unit 1 is consistent with the left-right direction XX in the figure, and the width direction of the indoor unit 1 is consistent with the front-back direction YY in the figure.

[0214] In this embodiment, the first air return port 141 extends at least along the length direction and the width direction, and the second air return port 143 extends at least along the length direction and the height direction; it can be understood that the first air return port 141 extends along the horizontal plane direction, and the second air return port 143 extends along the vertical plane direction.

[0215] When the external air suction opening is located below the indoor unit 1, at least a part of the first air return opening 141 overlaps with the external air suction opening in the height direction. With such an arrangement, during the operation of the indoor unit 1, external air flow can quickly flow into the air inlet cavity 11 through the external air suction opening and the first air return opening 141, improving the air flow efficiency and thus enhancing the performance of the indoor unit 1 provided in this embodiment.

[0216] Hereinafter, taking the example that the electric control box 93 is installed below the second housing 30 will be further introduced.

[0217] Please continue to refer to Figure 32 and Figure 33 , generally, the electric control box 93 includes a box body 931, a box cover 932, and an electric control board assembly 933. Among them, the box body 931 is connected to the second housing 30, the box cover 932 is covered on one side of the box body 931 facing the external air suction opening, and the box cover 932 and the box body 931 define a receiving cavity 93a, and the electric control board assembly 933 is arranged in the receiving cavity 93a. Therefore, the main heat-generating component in the electric control box 93 should be the electric control board assembly 933. In order to dissipate the heat generated by the electric control board assembly 933, it is necessary to enable external air flow to flow into the receiving cavity 93a and then flow out of the receiving cavity 93a into the air inlet cavity 11. Thus, a heat dissipation channel can be formed in the electric control box 93, and the air inlet end of the heat dissipation channel is communicated with the outside, and the air outlet end of the heat dissipation channel is communicated with the air inlet cavity 11 through the air suction opening 14, that is, the air outlet end of the heat dissipation channel is closer to the air suction opening 14 than the air inlet end of the heat dissipation channel. In this way, the fan 91 can suck the external air flow into the receiving cavity 93a and carry the heat released by the electric control board assembly 933 into the air inlet cavity 11 together.

[0218] Since the electric control board assembly 933 needs to be electrically connected to other modules inside the indoor unit 1, a wire passing hole 9317 can be opened on the side wall of the box body 931 to supply the wire harness of the electric control board assembly 933 to pass through and be electrically connected to other modules.

[0219] Please continue to refer to Figure 34 and Figure 35 , in order to form the above heat dissipation channel, at least one first heat dissipation hole 9321 penetrating the box cover 932 can be opened on the box cover 932, and the first heat dissipation hole 9321 forms the air inlet end of the heat dissipation channel to communicate the receiving cavity 93a with the outside; and at least one second heat dissipation hole 9318 is opened on the box body 931, and the second heat dissipation hole 9318 forms the air outlet end of the heat dissipation channel. In this way, when the fan 91 operates, external air flow can flow into the receiving cavity 93a through the first heat dissipation hole 9321, and then carry the heat dissipated by the electric control board assembly 933 and flow out of the receiving cavity 93a through the second heat dissipation hole 9318. After that, it flows into the air inlet cavity 11 through the second air return opening 143 to dissipate heat from the electric control box 93.

[0220] Moreover, at least a part of at least one second heat dissipation hole 9318 is arranged towards the air suction port 14, that is to say, at least a part of at least one second heat dissipation hole 9318 is arranged towards the second air return port 143. With such an arrangement, the heat dissipation air flow flowing out from the second heat dissipation hole 9318 can quickly flow to the second air return port 143 and flow into the air inlet cavity 11 through the second air return port 143.

[0221] At the air inlet end of the heat dissipation channel, that is, at the position where the first heat dissipation hole 9321 is located, in order to enable the air flow to quickly flow into the accommodation cavity 93a through the first heat dissipation hole 9321, an electronic control box flow guiding part 9323 can be formed on the box cover 932, and the electronic control box flow guiding part 9323 is arranged close to the second air return port 143, and the first heat dissipation hole 9321 is opened on the electronic control box flow guiding part 9323; and on the side of the electronic control box flow guiding part 9323 facing away from the bottom of the accommodation cavity 93a, an electronic control box flow guiding surface 9325 is formed, and the electronic control box flow guiding surface 9325 extends obliquely towards the air suction port 14. Specifically, the electronic control box flow guiding surface 9325 extends obliquely towards the second air return port 143. In this way, when the air flow flows into the first heat dissipation hole 9321, under the guiding action of the electronic control box flow guiding surface 9325, the air flow can be made to flow along a preset direction, so as to reduce the resistance suffered by the air flow during the flowing process to a certain extent, and enable the air flow to flow into the accommodation cavity 93a through the first heat dissipation hole 9321 more quickly, so as to improve the heat dissipation efficiency of the electronic control box 93.

[0222] In order to accelerate the air flow, in some alternative embodiments, both the first heat dissipation hole 9321 and the second heat dissipation hole 9318 can be multiple. The multiple first heat dissipation holes 9321 form a first heat dissipation area, and the multiple second heat dissipation holes 9318 form a second heat dissipation area; and the multiple first heat dissipation holes 9321 and the multiple second heat dissipation holes 9318 are arranged in rows and columns. Herein, the arrangement in rows and columns can be understood as that the multiple first heat dissipation holes 9321 are multiple rows in the thickness direction of the electronic control box 93, and the multiple first heat dissipation holes 9321 are multiple columns in the length direction of the electronic control box 93, and the arrangement mode of the multiple second heat dissipation holes 9318 can be the same as that of the multiple first heat dissipation holes 9321, that is, the multiple second heat dissipation holes 9318 are multiple rows in the thickness direction of the electronic control box 93, and the multiple second heat dissipation holes 9318 are multiple columns in the length direction of the electronic control box 93.

[0223] Through the above settings, not only can the air flow quickly flow into the accommodation cavity 93a through the first heat dissipation hole 9321 and can quickly flow out of the accommodation cavity 93a through the second heat dissipation hole 9318, but also, since more air flow flows into the accommodation cavity 93a through the first heat dissipation hole 9321, more heat generated by the electronic control board assembly 933 can be carried out of the accommodation cavity 93a, so as to achieve a better heat dissipation effect for the electronic control box 93.

[0224] It should be noted that the length direction of the above-mentioned electronic control box 93 is consistent with the length direction of the indoor unit 1, that is Figure 1 the XX-axis direction in

[0225] It can be understood that during the operation of the blower 91, along the height direction of the indoor unit 1, that is Figure 1 the up-and-down direction ZZ in

[0226] the air volume in the middle of the air suction port 14 is the largest, that is, the air volume in the middle of the second air return port 143 is relatively large. Further, in order to increase the gas flow rate flowing into the accommodation cavity 93a through the first heat dissipation holes 9321, in the height direction of the indoor unit 1, the first heat dissipation area is located in the middle position of the air suction port 14, that is, the first heat dissipation area is located in the middle area of the second air return port 143. In this way, the gas flow rate flowing into the accommodation cavity 93a through the first heat dissipation holes 9321 can be further increased, so that more heat generated by the electronic control board assembly 933 can be sucked away.

[0227] Please refer to Figure 33 , since both the first heat dissipation area and the second heat dissipation area have a certain coverage range in the length direction of the electronic control box 93, therefore, in order to facilitate the setting of the first heat dissipation holes 9321 and the second heat dissipation holes 9318, in the length direction of the electronic control box 93, the coverage lengths of the first heat dissipation area and the second heat dissipation area fall within the same length segment. In this way, not only can the gas flow rates through the multiple first heat dissipation holes 9321 and the multiple second heat dissipation holes 9318 be made equivalent, so that the heat dissipation air flow can flow out quickly, improving the heat dissipation efficiency of the electronic control box 93; in addition, it is convenient to open the first heat dissipation holes 9321 and the second heat dissipation holes 9318, so that the processing procedures of the electronic control box 93 are fewer, and the appearance of the electronic control box 93 is better.

[0228] It should be noted that the above first heat dissipation holes 9321 and second heat dissipation holes 9318 can be either round holes or square holes, etc. Here, no specific restrictions are imposed on the shapes of the first heat dissipation holes 9321 and the second heat dissipation holes 9318.

[0229] When the electric control box 93 is arranged below the second housing 30, in order to avoid increasing the size of the indoor unit 1 in the height direction of the indoor unit 1, an upwardly concave installation cavity 18 can be arranged at the bottom of the second housing 30. The installation cavity 18 is communicated with the air inlet cavity 11 through the air suction port 14. The installation cavity 18 has a first side wall 181, a second side wall 182 and an exposed opening 183 connected together. The exposed opening 183 is arranged downward and the first side wall 181 faces the exposed opening 183. The first side wall 181 extends between the second air return port 143 and the second side wall 182, and the second side wall 182 faces the second air return port 143; the electric control box 93 is installed on the first side wall 181. In this way, the electric control box 93 can be accommodated in the installation cavity 18 without changing the height of the indoor unit 1, making the structure of the indoor unit 1 provided in this embodiment more compact.

[0230] Optionally, referring to Figure 36 The first side wall 181 is formed by the wall surface of the housing main body 311 facing away from the diffuser cavity 12, and the second side wall 182 is formed by the wall surface of the water receiving tray 60 facing away from the heat exchange cavity 13

[0231] In some alternative embodiments, the installation cavity 18 opens downward. In this way, when the grille on the ceiling is removed, the electric control box 93 can be exposed, facilitating the disassembly and repair of the electric control box 93.

[0232] As can be seen from the above, the installation cavity 18 is located on the side of the first air return port 141, and the first air return port 141 and the external air suction port are overlapped in the height direction. In some alternative embodiments, at least part of the installation cavity 18 is also overlapped with the external air suction port in the height direction. That is to say, the external air flow can directly enter the installation cavity 18 through the external air suction port to dissipate heat from the electric control box 93, thereby improving the heat dissipation efficiency of the electric control box 93.

[0233] Since the electronic control box 93 is installed on the first side wall 181, in order to improve the heat dissipation efficiency of the electronic control box 93, the flow resistance of the air flow in the electronic control box 93 can be reduced. For example, the extending direction of the bottom wall of the accommodating cavity 93a is made to be approximately the same as the flow direction of the air flow. And since the electronic control box 93 is installed on the first side wall 181, therefore, it is only necessary to make the extending direction of the first side wall 181 close to the flow direction of the air flow. Thus, in some alternative embodiments, the first side wall 181 extends in the height direction, and the first side wall 181 and the second air return opening 143 extend close to each other from bottom to top. In this way, the extending direction of the first side wall 181 is relatively close to the flow direction of the air flow, which can reduce the flow resistance of the air flow in the accommodating cavity 93a, increase the flow velocity of the air flow, and further improve the heat dissipation efficiency of the electronic control box 93.

[0234] Furthermore, in order to facilitate the installation of the electronic control box 93 on the first side wall 181, the wall surface of the first side wall 181 can be set as an inclined wall surface. In this way, not only can the flow resistance of the air flow in the accommodating cavity 93a be small, but also the smoothness of the surface of the first side wall 181 can be improved, which is beneficial to the installation of the electronic control box 93.

[0235] It should be noted that in some embodiments, a detachable connection manner can be adopted between the electronic control box 93 and the lower housing of the diffuser chamber 12. Specifically, a detachable connection is made between the box body 931 and the lower housing of the diffuser chamber 12. For example, it is detachably connected through a screwing structure and / or a clamping structure. It can be understood that the electronic control box 93 and the lower housing of the diffuser chamber 12 can be detachably connected through a screwing structure, or can be detachably connected through a clamping structure, or can also be detachably connected through a combination of a screwing structure and a clamping structure. Here, no specific limitation is made on the connection manner between the box body 931 of the electronic control box 93 and the lower housing of the diffuser chamber 12.

[0236] Generally, when the electronic control box 93 is overhauled, the internal electronic control board assembly 933 is overhauled. Therefore, in order to facilitate the overhaul of the electronic control board assembly 933, in this embodiment, a detachable connection manner can also be adopted between the box cover 932 and the box body 931. In this way, when the problem of the electronic control board assembly 933 is not serious, the box cover 932 can be only removed from the box body 931, and the electronic control board assembly 933 can be overhauled.

[0237] Please continue to refer to Figure 37 , Figure 37It is a schematic structural diagram of the positioning structure between the electronic control box 93 and the lower housing of the diffuser chamber 12 in the indoor unit 1 provided by the embodiment of the present application. In order to improve the installation efficiency between the electronic control box 93 and the second housing 30, a positioning structure can be provided between the electronic control box 93 and the first side wall 181, and the positioning structure is used to limit the relative position between the electronic control box 93 and the lower housing of the diffuser chamber 12. In this way, when installing the electronic control box 93 and the lower housing of the diffuser chamber 12, the positions between the electronic control box 93 and the lower housing of the diffuser chamber 12 can be determined first, and then the electronic control box 93 and the lower housing of the diffuser chamber 12 can be connected together through the above-mentioned screwing structure and clamping structure.

[0238] In some alternative embodiments, the positioning structure includes a positioning post 93b and a positioning groove 93c, and the positioning post 93b is inserted into the positioning groove 93c; one of the positioning post 93b and the positioning groove 93c is provided on the side of the box body 931 of the electronic control box 93 facing the second housing 30, and the other of the positioning post 93b and the positioning groove 93c is provided on the side of the lower housing of the diffuser chamber 12 facing the box body 931. In the specific embodiment of this embodiment, the axial direction of the positioning post 93b is consistent with the thickness direction of the electronic control box 93, and the depth direction of the positioning groove 93c is also consistent with the depth direction of the electronic control box 93. The positioning post 93b is provided on the box body 931, and the positioning groove 93c is provided on the lower housing of the diffuser chamber 12. In this way, when installing the electronic control box 93 on the lower housing of the diffuser chamber 12, the positioning post 93b and the positioning groove 93c can be aligned first, and then the electronic control box 93 and the lower housing of the diffuser chamber 12 can be connected together through the above-mentioned screwing structure and / or clamping structure.

[0239] In order to further improve the installation efficiency of the electronic control box 93, a plurality of positioning posts 93b and a plurality of positioning grooves 93c corresponding to the plurality of positioning posts 93b can be provided. Here, the number of the positioning posts 93b and the number of the positioning grooves 93c are not limited.

[0240] In some embodiments, in order to allow more air flow to enter the air inlet side of the installation cavity 18, the angle between the first side wall 181 and the second side wall 182 can be limited so that the opening of the air inlet side of the installation cavity 18 is larger. Thus, the angle between the second side wall 182 and the first side wall 181 can be greater than 90 degrees. In this way, the opening of the air inlet side of the installation cavity 18 is larger, ensuring that more air flow enters the electronic control box 93, and enabling more heat generated by the electronic control board assembly 933 to be carried out of the accommodation cavity 93a.

[0241] In some other embodiments, the air flow rate flowing into the electronic control box 93 can also be ensured by restricting the opening size of the installation cavity 18. Specifically, the opening of the installation cavity 18 gradually decreases from bottom to top. That is to say, the opening at the lower part of the installation cavity 18 is larger, and the opening at the lower part of the installation cavity 18 is just the air inlet side of the installation cavity 18. Therefore, by restricting the opening size of the installation cavity 18, the air flow rate at the air inlet side of the installation cavity 18 can also be made larger, so as to achieve a better heat dissipation effect on the electronic control box 93.

[0242] Please refer to Figure 29 and Figure 31 As shown, in some embodiments, in order to avoid damage to people caused by the fan 91 and to protect the fan 91 at the same time, a protective grille 98 can be provided at the air suction port 14. One side of the protective grille 98 is connected to the upper housing 21 of the air inlet cavity, and the other side of the protective grille 98 is connected to the lower housing of the diffuser cavity 12. In this way, by providing a grille at the air suction port 14, when installing or disassembling the electronic control box 93, it can be avoided to a certain extent that the fan 91 causes harm to people, and at the same time, the fan 91 can be protected, so that the fan 91 maintains good performance. Moreover, it can be avoided to a certain extent that larger insects or foreign objects enter the air inlet cavity 11 through the air suction port 14.

[0243] When the protective grille 98 is provided, the air inlet of the installation cavity 18 may be affected due to the presence of the protective grille 98. Therefore, in order to avoid this phenomenon, the protective grille 98 and the electronic control box 93 are spaced apart in the width direction of the indoor unit 1. In this way, even if the protective grille 98 is provided, the air flow rate entering the installation cavity 18 will not be affected greatly, ensuring the heat dissipation effect of the electronic control box 93; at the same time, it can also be avoided to a certain extent that the protective grille 98 interferes with the installation or disassembly of the electronic control box 93.

[0244] Specifically, in order to protect both the first air return port 141 and the second air return port 143, the above-mentioned protective grille 98 can include a first grille portion 981 and a second grille portion 983 connected together. The first grille portion 981 is provided at the first air return port 141, and the second grille portion 983 is provided at the second air return port 143. In this way, the entire air suction port 14 can be protected and blocked by the protective grille 98, improving the protective effect of the protective grille 98 on the fan 91.

[0245] Similarly, to ensure the air intake volume on the air inlet side of the installation cavity 18, the distance between the second grille portion 983 and the electric control box 93 can be restricted. For example, in the width direction of the indoor unit 1, the distance between the second grille portion 983 and the electric control box 93 gradually decreases from bottom to top. That is to say, on the air inlet side of the installation cavity 18, the distance between the electric control box 93 and the second grille portion 983 is the largest. In this way, the air flow rate on the air inlet side of the installation cavity 18 is relatively large, which can further avoid, to a certain extent, the influence of the setting of the protective grille 98 on the heat dissipation of the electric control box 93.

[0246] In the attached drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components; in the description of the present application, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the attached drawings. This is only for the convenience of describing the present 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 positional relationship in the attached drawings are only for illustrative purposes and should not be construed as a limitation to the present application. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0247] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. An air duct assembly is applied to an indoor unit, and the indoor unit includes a fan and a heat exchanger. It is characterized in that, The air duct assembly includes a first housing and a second housing. The first housing and the second housing cooperate to define a diffuser chamber and a heat exchange chamber that are in communication. The diffuser chamber is configured to communicate with the downstream of the fan and guide the gas flow to the heat exchange chamber. The heat exchange chamber is configured to house the heat exchanger; Wherein, the diffuser chamber is located on one side of the heat exchange chamber.

2. The air duct assembly according to claim 1, characterized in that, Between the diffuser chamber and the heat exchanger, the air duct assembly does not form an obstruction in the flow direction of the gas flowing to the heat exchanger.

3. The air duct assembly according to claim 1, characterized in that, The diffuser chamber does not extend into the heat exchange chamber.

4. The air duct assembly according to claim 3, characterized in that, Along the direction from the diffuser chamber to the heat exchange chamber, the transverse flow area of the gas in the diffuser chamber is set to increase, and from the diffuser chamber to the heat exchange chamber, the transverse flow area of the gas remains unchanged or increases.

5. The air duct assembly according to claim 4, characterized in that, Along the direction from the diffuser chamber to the heat exchange chamber, the diffuser chamber is configured to gradually expand.

6. The air duct assembly according to claim 1, wherein, The first housing includes an upper diffuser chamber housing and an upper heat exchange chamber housing. The upper diffuser chamber housing defines the top wall of the diffuser chamber. The upper heat exchange chamber housing defines the top wall of the heat exchange chamber. The second housing includes a lower diffuser chamber housing and a water receiving tray. The lower diffuser chamber housing defines the bottom wall of the diffuser chamber. The water receiving tray defines the bottom wall of the heat exchange chamber; The upper diffuser chamber housing is connected to the upper heat exchange chamber housing. The lower diffuser chamber housing is connected to the water receiving tray. On the upstream side of the heat exchange chamber, the upper heat exchange chamber housing extends upward relative to the upper diffuser chamber housing, and / or, on the upstream side of the heat exchange chamber, the water receiving tray extends downward relative to the lower diffuser chamber housing to increase the flow area of the gas.

7. The air duct assembly according to claim 6, wherein The upper diffuser chamber housing slopes upward in a direction away from the upper heat exchange chamber housing. The upper heat exchange chamber housing includes a connected top wall and side wall. The side wall is connected between the upper diffuser chamber housing and the top wall, and the side wall extends upward.

8. The air duct assembly according to claim 6, wherein, The lower diffuser chamber housing slopes upward in a direction away from the water receiving tray, and the lower diffuser chamber housing and the water receiving tray are in smooth transition.

9. The air duct assembly according to claim 8, wherein The water receiving tray includes a bottom wall and a side wall. The side wall is connected between the lower diffuser chamber housing and the bottom wall. An angle greater than or equal to 90 degrees is formed between the lower diffuser chamber housing and the side wall.

10. The air duct assembly according to claim 1, characterized in that, The first housing includes an upper diffuser chamber housing and an upper heat exchange chamber housing. The upper diffuser chamber housing defines the top wall of the diffuser chamber. The upper heat exchange chamber housing defines the top wall of the heat exchange chamber. The second housing includes a housing main body and a water receiving tray. The housing main body defines at least part of the bottom wall of the diffuser chamber. The water receiving tray defines the bottom wall of the heat exchange chamber; Wherein, the upper diffuser chamber housing and the upper heat exchange chamber housing are integrally formed components, and / or, the housing main body and the water receiving tray are integrally formed components.

11. The air duct assembly according to claim 1, wherein, The first housing and the second housing also cooperate to define an air inlet chamber, which is configured to house the fan, and the downstream side of the air inlet chamber communicates with the diffuser chamber; The first housing includes an upper diffuser chamber housing, an upper heat exchange chamber housing, an upper air inlet chamber housing, and a rear air inlet chamber housing. The upper diffuser chamber housing, the upper heat exchange chamber housing, the upper air inlet chamber housing, and the rear air inlet chamber housing are integrally formed components.

12. The air duct assembly according to any one of claims 1 to 11, characterized in that, The first housing and the second housing also cooperate to define an air inlet cavity, which is configured to house the fan, and the downstream of the air inlet cavity communicates with the diffuser cavity; The air duct assembly further includes a volute tongue disposed at the junction of the air inlet cavity and the diffuser cavity. The volute tongue is configured to guide the air flow from the air inlet cavity to the diffuser cavity, and a plurality of flow guiding grooves are spaced on one side of the volute tongue facing the air inlet cavity. The flow guiding grooves extend from the air inlet cavity to the diffuser cavity.

13. The air duct assembly according to claim 12, wherein, The volute tongue includes: A volute tongue main body having a main body surface; and A plurality of flow guiding ribs protruding from the main body surface at intervals along the length direction of the air duct assembly. The space between two adjacent flow guiding ribs and the main body surface jointly defines the flow guiding groove.

14. The air duct assembly according to claim 13, characterized in that, Projecting along the length direction of the air duct assembly, the part of the main body surface at the bottom of the flow guiding groove constitutes a bottom profile line, and the end point of the contour line of the flow guiding rib extending towards the lower housing of the diffuser cavity intersects with the bottom profile line.

15. The air duct assembly according to claim 13, characterized in that, The connection between the two ends of the flow guiding rib and the main body surface is smoothly transitioned; And / or, the contour line shape of the flow guiding rib is configured as a wavy shape, a broken line shape or a single arc shape bulging away from the volute tongue main body.

16. The air duct assembly according to claim 12, wherein, The second housing includes a first split structure and a second split structure. The first split structure and the second split structure are detachably connected, and the first split structure and the second split structure cooperate to configure the bottom wall of the diffuser cavity and part of the inner wall of the air inlet cavity; Wherein, part of the second split structure configures the volute tongue.

17. The air duct assembly according to claim 16, wherein, The first split structure includes: A housing main body; and A support portion connected to one side of the housing main body and detachably connected to the second split structure. The support portion, the housing main body and the second split structure cooperate to configure the bottom wall of the diffuser cavity; Wherein, the support structure and the housing main body are an integral structure, and / or a hollow cavity is formed by enclosing the second split structure and the support portion.

18. The air duct assembly according to claim 1, wherein, The first housing and the second housing also cooperate to define an air inlet cavity communicating with the diffuser cavity, and the air inlet cavity is configured to house the fan; The second housing includes a return channel, a first surface constituting the bottom wall of the diffuser cavity, and a second surface constituting part of the cavity wall surface of the air inlet cavity. A first opening is formed in the first surface, and a second opening is formed in the second surface. The return channel extends from the first opening to the second opening.

19. The air duct assembly according to claim 18, wherein, The return channel is curved; And / or, the width dimension of the return channel remains unchanged or gradually expands from the first opening to the second opening.

20. The air duct assembly according to claim 18, characterized in that, The extension line of the orientation of the second opening of the return channel passes through the fan, and the included angle with the outer peripheral tangent of the fan is θ, and the θ is less than or equal to 15 degrees and greater than or equal to 0 degrees; Or, the extension line of the orientation of the second opening of the return channel passes through the outside of the fan, and the included angle with the outer peripheral tangent of the fan is β, and the β is less than or equal to 45 degrees and greater than or equal to 0 degrees.

21. The air duct assembly according to claim 20, characterized in that, The θ is equal to 0 degree or the β is equal to 0 degree, so that the extension line of the orientation of the second opening of the return air channel coincides with the outer peripheral tangent of the fan.

22. The air duct component according to claim 18, characterized in that, The second housing includes: a housing main body provided with the first surface; a supporting portion connected to a side of the housing main body facing away from the first surface, and one side of the supporting portion is configured as a first return air surface; and a guiding member connected to a side of the housing main body facing away from the first surface and spaced apart from the supporting portion. A side of the guiding member facing the supporting portion is configured as a second return air surface. The second return air surface and the first return air surface cooperate to form the return air channel. A second surface is provided at an end of the guiding member away from the housing main body.

23. The air duct assembly according to claim 22, wherein, The guiding member includes a connecting portion, a guiding portion, and a cavity wall portion. The connecting portion is stacked on a side of the housing main body facing away from the first surface and is detachably mounted on the housing main body. The guiding portion is connected to the connecting portion and is disposed at an angle with the connecting portion. The cavity wall portion is connected to an end of the guiding portion facing away from the connecting portion and extends in a direction away from the housing main body. The cavity wall portion is disposed at an angle with the guiding portion. The cavity wall portion has the second surface. The first housing and at least the cavity wall portion define the air inlet cavity.

24. The air duct assembly according to claim 23, wherein Further included is a grille detachably connected to the cavity wall portion and covering the air inlet side of the air inlet cavity.

25. An indoor unit, characterized in that, It includes a fan, a heat exchanger, and an air duct assembly according to any one of claims 1 to 24. The first housing and the second housing further cooperate to define an air inlet cavity communicating with the diffuser cavity. The fan is received in the air inlet cavity, and the heat exchanger is received in the heat exchange cavity.

26. The indoor unit according to claim 25, wherein, The indoor unit is a duct machine, and the fan is a cross-flow fan.

27. The indoor unit according to claim 25, characterized in that, The first housing and the second housing further configure and form an air outlet communicating with the heat exchange cavity. The heat exchanger is arranged in an arc shape arched toward the air outlet. Among them, the central axis of the diffuser cavity passes through the arc top of the heat exchanger.

28. The indoor unit according to claim 27, characterized in that, A plurality of refrigerant pipes perpendicular to the air outlet direction are arranged in the heat exchanger. Along the up-and-down direction of the installation environment, the number of refrigerant pipes in the middle of the heat exchanger is more than that at the upper and lower ends of the heat exchanger; and / or, the orientation of the air outlet is the horizontal direction.

29. The indoor unit according to claim 25, characterized in that, The first housing and the second housing further cooperate to define an air suction port communicating with the air inlet cavity, and at least part of the air suction port faces downward.

30. The indoor unit according to claim 29, characterized in that, Further included is: an electric control box installed outside the second housing, and at least part of the air suction port is located between the fan and the electric control box.

31. A heating, ventilation and air conditioning (HVAC) system, characterized in that, It includes an outdoor unit and an indoor unit according to any one of claims 24 to 30. The outdoor unit and the heat exchanger form a refrigerant cycle.

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