Indoor unit and heating, ventilation and air conditioning device

Abstract

An indoor unit (1) and a heating, ventilation and air conditioning device. The indoor unit (1) comprises an air duct assembly (10) and a fan wheel (911), the air duct assembly (10) defines a fan chamber (11), the fan wheel (911) is accommodated in the fan chamber (11), the air duct assembly (10) comprises a volute tongue (40), and the volute tongue (40) comprises a first volute tongue portion (41) and a second volute tongue portion (42) which are connected, wherein in an air supply direction of the fan wheel (911), the second volute tongue portion (42) is arranged closer to the fan wheel (911) than the first volute tongue portion (41).

Description

Indoor units and HVAC equipment

[0001] This application claims priority to the Chinese patent application with application number 2024100462786, filed with the China Patent Office on January 11, 2024, and with the invention name “Indoor Unit”, the Chinese patent application with application number 2024100479151, with the invention name “Indoor Unit and HVAC System”, and the Chinese patent application with application number 2024102743464, filed with the China Patent Office on March 11, 2024, and with the invention name “Indoor Unit and HVAC Equipment”, all of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of HVAC technology, and in particular to an indoor unit and HVAC equipment using the indoor unit. Background Art

[0003] In the prior art, a volute tongue is installed within the air duct of the indoor unit to guide part of the airflow delivered by the impeller into the diffuser chamber. However, the airflow delivered by the impeller of most indoor units does not maintain a consistent axial volume, resulting in uneven airflow to different areas of the volute tongue. This, in turn, causes uneven axial flow at the indoor unit's air outlet, affecting the airflow quality. Summary of the Invention

[0004] The embodiment of the present application provides an indoor unit and HVAC equipment, which can reduce the flow difference between the airflow flowing to the first volute tongue portion and the airflow flowing to the second volute tongue portion, thereby making the air outlet effect of the indoor unit uniform and reducing noise generation.

[0005] In a first aspect, an embodiment of the present application provides an indoor unit, the indoor unit comprising an air duct assembly and a wind wheel, the air duct assembly defining a fan cavity, the wind wheel being accommodated in the fan cavity;

[0006] The air duct assembly includes a volute tongue, which includes a first volute tongue portion and a second volute tongue portion connected to each other, wherein in the air supply direction of the wind wheel, the second volute tongue portion is arranged closer to the wind wheel than the first volute tongue portion.

[0007] In some embodiments, the number of the second volute tongue portions is two, and the two second volute tongue portions are connected to opposite ends of the first volute tongue portion.

[0008] Based on the above embodiment, the flow difference between the airflow flowing to the first volute tongue portion and the airflow flowing to the two second volute tongue portions can be reduced, thereby making the air outlet effect of the indoor unit uniform and reducing the generation of noise.

[0009] In some embodiments, in the air supply direction of the wind wheel, the distances between each of the second volute tongue portions and the wind wheel are equal or unequal.

[0010] Based on the above embodiment, the flow rate difference between the airflows flowing to the two second volute tongue portions is reduced, thereby making the air outlet effect of the indoor unit uniform and reducing the generation of noise.

[0011] In some embodiments, the number of the first volute tongue portions is two, and the two first volute tongue portions are connected to opposite ends of the second volute tongue portion.

[0012] Based on the above embodiment, the flow difference between the airflow flowing to the first volute tongue portion and the airflow flowing to the two second volute tongue portions is reduced, thereby making the air outlet effect of the indoor unit uniform and reducing the generation of noise.

[0013] In some embodiments, in the air supply direction of the wind wheel, the distances between each of the first volute tongue portions and the wind wheel are equal or unequal.

[0014] Based on the above embodiment, the flow rate difference between the airflows flowing to the two first volute tongue portions is reduced, thereby making the air outlet effect of the indoor unit uniform and reducing the generation of noise.

[0015] In some embodiments, a plurality of first guide ribs arranged at intervals are protruded from the first volute tongue portion, and two adjacent first guide ribs cooperate with the first volute tongue portion to define a first guide groove;

[0016] A plurality of second guide ribs arranged at intervals are protruded from each of the second volute tongue portions, and a second guide groove is defined between two adjacent second guide ribs and the second volute tongue portion;

[0017] Wherein, in the air supply direction of the wind wheel, the second guide groove is arranged closer to the wind wheel than the first guide groove.

[0018] Based on the above embodiment, when noisy air flows through the snail tongue, it is separated by the first and second guide ribs, thereby weakening the energy of the noise, reducing the impact of the noise on the user, and reducing the noise generation, thereby improving the user experience. Furthermore, under the guiding effect of the multiple first and second guide ribs, the flow of air in the axial direction can be reduced, thereby reducing the energy loss of the airflow during the flow to the air outlet.

[0019] In some embodiments, the connection between the first volute tongue portion and the second volute tongue portion is arranged in a smooth transition; or,

[0020] The connection between the first volute tongue portion and the second volute tongue portion is arranged in a stepped transition.

[0021] Based on the above embodiment, the connection between the first volute tongue portion and the second volute tongue portion is a smooth transition or a stepped transition, so as to reduce the generation of noise.

[0022] In some embodiments, the first volute tongue portion and the second volute tongue portion are an integral structure.

[0023] Based on the above embodiment, the connection between the first volute tongue portion and the second volute tongue portion is made more stable, and the number of assembly steps therebetween is reduced.

[0024] In some embodiments, the indoor unit further includes a heat exchanger, the air duct assembly includes a first shell and a second shell, the second shell includes a diffuser chamber bottom shell, a water receiving tray, and the volute tongue, and opposite sides of the diffuser chamber bottom shell are respectively connected to the volute tongue and the water receiving tray;

[0025] The first housing defines the fan cavity, and cooperates with the first volute tongue portion, the second volute tongue portion, and the diffuser cavity bottom shell to define a diffuser cavity. The water receiving tray cooperates with the first housing to define a heat exchange cavity. The heat exchanger is accommodated in the heat exchange cavity. The fan cavity, the diffuser cavity, and the heat exchange cavity are sequentially connected.

[0026] Wherein, at least a portion of the diffuser chamber bottom shell and the water receiving tray are an integrated structure.

[0027] Based on the above embodiment, the connection between the diffuser chamber bottom shell and the water receiving tray is made more secure, and the assembly steps are reduced to improve assembly efficiency.

[0028] In some embodiments, the volute tongue has a windward surface, a wind-guiding surface, and a transition surface, the windward surface faces the wind wheel, the wind-guiding surface is arranged at an angle to the windward surface, and is configured to guide the airflow out of the wind wheel, and the transition surface connects the windward surface and the wind-guiding surface;

[0029] Wherein, the transition surface has a sinking area, and the sinking area is concave toward the direction close to the wind guide surface.

[0030] In some embodiments, compared with the boundary line between the sinking area and the windward surface, the boundary line between the sinking area and the wind guide surface is further away from the wind wheel.

[0031] In some embodiments, the sunken area is an arc surface that arches toward the wind guide surface.

[0032] In some embodiments, the transition surface is further provided with an arched area, which is arched in a direction away from the wind guide surface and smoothly transitions to be connected with the sunken area.

[0033] In some embodiments, the volute tongue is extended along the axial direction of the wind wheel, the sinking area is arranged in the middle of the volute tongue and extends toward both ends of the volute tongue, and the arched area is arranged at both ends of the sinking area along the extension direction of the volute tongue.

[0034] In some embodiments, the volute tongue has a width direction perpendicular to its own extension direction, and the width of the sinking area along the width direction gradually decreases from the middle of the volute tongue to both ends of the volute tongue.

[0035] In some embodiments, the distance between the sinking area and the wind wheel gradually decreases from the middle of the volute tongue to the two ends of the volute tongue.

[0036] In some embodiments, the sinking area is symmetrically arranged about a midline of the volute tongue perpendicular to its own extension direction.

[0037] In some embodiments, the volute tongue further comprises a plurality of guide ribs, wherein the plurality of guide ribs are connected to at least the transition surface and are arranged at intervals along the axial direction of the wind wheel;

[0038] Projected along the axial direction of the wind wheel, the guide rib has a guide rib profile line, and the guide rib profile line is parallel to the surface of the sinking area.

[0039] In some embodiments, a fan is further included, wherein the fan is a cross-flow fan and has the wind wheel, and the air duct assembly includes a first shell and a second shell, the first shell and the second shell cooperate to define the fan cavity and a diffuser cavity connected to the fan cavity, and the fan is accommodated in the fan cavity;

[0040] The second housing includes an air inlet surface, a volute tongue surface, and a pressure diffuser surface connected in sequence, the air inlet surface is configured as a portion of the cavity wall of the fan cavity, and the pressure diffuser surface is configured as at least a portion of the cavity bottom wall of the pressure diffuser cavity;

[0041] A shoulder is provided at an end portion of the air inlet surface along the axial direction of the fan, and the shoulder is connected to the volute tongue surface, wherein the shoulder is protruded toward the fan compared to the air inlet surface.

[0042] In some embodiments, the side of the shoulder facing the fan includes a first surface and a second surface arranged at an angle, the first surface is connected between the volute tongue surface and the second surface, and the second surface extends along the extension direction of the air inlet surface;

[0043] Wherein, the extension length of the first surface is smaller than the extension length of the second surface.

[0044] In some embodiments, in a longitudinal section of the indoor unit along the airflow direction, the center of the fan is defined as O, the connection point between the volute tongue surface and the diffuser surface is defined as A, the connection point between the volute tongue surface and the air inlet surface is defined as B, and the connection point between the first surface and the second surface is defined as C;

[0045] The angle between the line passing through points O and A and the line passing through points O and B is α, and the angle between the line passing through points O and A and the line passing through points O and C is β, where the following conditions are met: α minus β must be greater than or equal to 5 degrees and less than or equal to 30 degrees.

[0046] In some embodiments, the first surface extends vertically downward in the height direction of the indoor unit, and an angle β between the first surface and the second surface is greater than 0 degrees and less than 60 degrees.

[0047] In some embodiments, the connection between the first surface and the volute tongue surface is a smooth transition;

[0048] And / or, the connection between the first surface and the second surface is a smooth transition.

[0049] In some embodiments, the connection between the first surface and the air inlet surface is a smooth transition, and the connection between the second surface and the air inlet surface is a smooth transition.

[0050] In some embodiments, the connection between the first surface and the air inlet surface is in a stepped transition, and the connection between the second surface and the air inlet surface is in a stepped transition.

[0051] In some embodiments, in the radial direction of the fan, the distance between the first surface and the outer peripheral surface of the fan is greater than or equal to 3.5 mm and less than or equal to 7.5 mm.

[0052] In some embodiments, in the radial direction of the fan, the distance between the second surface and the outer peripheral surface of the fan is greater than or equal to 7.5 mm.

[0053] In some embodiments, the shoulder includes two portions, which are respectively arranged at two opposite end positions of the air inlet surface along the axial direction of the fan.

[0054] In some embodiments, in the axial direction of the fan, the width of each shoulder is greater than 10 mm and less than 60 mm.

[0055] In some embodiments, in the axial direction of the fan, the ratio of the width of each shoulder to the width of the air inlet surface is less than or equal to one third.

[0056] In a second aspect, an embodiment of the present application provides a HVAC device, which includes an outdoor unit and an indoor unit as described above, wherein the indoor unit and the outdoor unit form a refrigerant cycle.

[0057] Based on the indoor unit and HVAC equipment of the embodiment of the present application, by arranging the second volute tongue portion closer to the wind wheel than the first volute tongue portion in the air supply direction of the wind wheel, the embodiment of the present application has the following technical effects:

[0058] By shortening the distance between the second volute tongue portion and the wind wheel, the amount of leakage generated by the airflow delivered by the wind wheel during the process of flowing to the second volute tongue portion can be reduced compared to the amount of leakage generated during the process of the airflow flowing to the first volute tongue portion, thereby making the flow rate of the airflow delivered by the wind wheel to the volute tongue as equal as possible in the axial direction of the wind wheel. In this way, the final air output of the indoor unit can be as balanced as possible in the width direction of the indoor unit, making the overall air output effect of the indoor unit more uniform and improving the user experience. In addition, on the basis of ensuring that the flow rate of the airflow flowing to the first volute tongue portion and the flow rate of the airflow flowing to the second volute tongue portion are as consistent as possible, a pressure difference between the airflow flowing through the first volute tongue portion and the airflow flowing through the second volute tongue portion is avoided, thereby reducing the occurrence of a large flow of airflow flowing into a small flow of airflow. In this way, the generation of vortices can be reduced, thereby effectively reducing the noise in the indoor unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0060] FIG1 is a schematic structural diagram of an indoor unit according to an embodiment of the present application;

[0061] FIG2 is a schematic diagram of the exploded structure of the indoor unit shown in FIG1 ;

[0062] FIG3 is a schematic cross-sectional view of the AA plane in FIG1 ;

[0063] FIG4 is a schematic cross-sectional view of the BB plane in FIG1 ;

[0064] FIG5 is a schematic cross-sectional view of the BB surface portion shown in FIG4 ;

[0065] FIG6 is a partial enlarged view of point C in FIG5 ;

[0066] FIG7 is a partial enlarged view of point D in FIG5 ;

[0067] FIG8 is a schematic structural diagram of the volute tongue shown in FIG5 ;

[0068] FIG9 is a partial enlarged view of point E in FIG8 ;

[0069] FIG10 is a partial enlarged view of point F in FIG8 ;

[0070] FIG11 is a schematic structural diagram of an indoor unit according to an embodiment of the present application;

[0071] FIG12 is a schematic diagram of the exploded structure of the indoor unit in FIG11;

[0072] FIG13 is a schematic diagram of the top view of the indoor unit in FIG11;

[0073] FIG14 is a schematic cross-sectional view of the indoor unit at section GG in FIG13 ;

[0074] FIG15 is a schematic top view of a partial structure of another embodiment of the indoor unit of the present application;

[0075] FIG16 is an enlarged structural diagram of point H in FIG14;

[0076] FIG17 is a schematic cross-sectional view of section GG of an embodiment of a second housing of the present application;

[0077] FIG18 is an enlarged structural diagram of point J in FIG17 ;

[0078] FIG19 is a schematic diagram of an exploded structure of yet another embodiment of the second housing of the present application;

[0079] FIG20 is a schematic structural diagram of an indoor unit according to an embodiment of the present application from one perspective;

[0080] FIG21 is a schematic structural diagram of the indoor unit shown in FIG20 with the outer shell removed;

[0081] FIG22 is a schematic structural diagram of the indoor unit shown in FIG20 from another perspective;

[0082] FIG23 is a cross-sectional view of the KK section in FIG22;

[0083] FIG24 is a partial enlarged view of point M in FIG23;

[0084] FIG25 is a cross-sectional view of the NN section in FIG22;

[0085] FIG26 is a partial enlarged view of point P in FIG25 ;

[0086] FIG27 is a schematic structural diagram of the indoor unit shown in FIG22 with the cross-flow fan removed;

[0087] FIG28 is a partial enlarged view of point Q in FIG27;

[0088] FIG29 is a schematic structural diagram of an embodiment of the second housing shown in FIG22 with the heat exchange chamber bottom shell removed;

[0089] FIG30 is a schematic structural diagram of another embodiment of the second shell shown in FIG22 with the bottom shell of the heat exchange chamber removed.

[0090] Explanation of the accompanying symbols: 1. Indoor unit; 10. Air duct assembly; 11. Fan cavity; 12. Diffuser cavity; 13. Heat exchange cavity; 14. Return air outlet; 15. Air outlet; 16. Hollow cavity; 20. First shell; 21. Upper cover; 211. Fan cavity shell; 212. Diffuser cavity top shell; 213. Heat exchange cavity top shell; 22. Side panel; 30. Second shell; 31. Air inlet surface; 32. Volute tongue surface; 33. Diffuser surface; 34. Shoulder; 341. First surface; 343. Second surface; 40. Volute tongue; 41. First volute tongue portion; 411. First guide rib; 412. First guide groove; 42. Second volute tongue portion; 421. Second guide rib; 422. Second guide groove Groove; 43, volute tongue body; 43a, windward surface; 43b, wind-guiding surface; 43c, transition surface; 43c1, sinking area; 43c2, arched area; 44, guide rib; 45, supporting structure; 50, diffuser chamber bottom shell; 52, guide plate; 60, water collection tray; 80, first insulation layer; 81, second insulation layer; 90, outer shell; 91, fan; 91a, air inlet side; 91b, air outlet side; 911, wind wheel; 92, heat exchanger; 93, electric control box; 98, grille.

[0091] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0092] In order to make the purpose, technical solutions and advantages of this application clearer, the following part will further describe the embodiments of this application in detail with reference to the accompanying drawings.

[0093] 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 embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application, as detailed in the appended claims.

[0094] In the description of this application, it should be understood that the terms "first", "second", etc. are only provided for descriptive purposes and are not to be understood 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 the specific circumstances. In addition, in the description of this application, unless otherwise specified, "multiple" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship.

[0095] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the relevant listed items.

[0096] First embodiment

[0097] In the prior art, a volute tongue is installed within the air duct of the indoor unit to guide part of the airflow delivered by the impeller into the diffuser chamber. However, the airflow delivered by the impeller of most indoor units does not maintain a consistent axial volume, resulting in uneven airflow to different areas of the volute tongue. This, in turn, causes uneven axial flow at the indoor unit's air outlet, affecting the airflow quality.

[0098] To solve the above problems, please refer to Figure 1. One aspect of the present application proposes a HVAC device. In the embodiment of the present application, the HVAC device includes but is not limited to air conditioners, multi-split units, and heat pumps, and can be used in large-scale places such as shopping malls and office buildings. The HVAC device may include an indoor unit 1, an outdoor unit, and a connecting pipe. The indoor unit 1 is connected to the outdoor unit through a connecting pipe so that a refrigerant cycle is formed between the indoor unit 1 and the outdoor unit. In some actual usage scenarios, the indoor unit 1 of the present application can be installed indoors, the outdoor unit is responsible for cooling or heating, and transports the refrigerant through the connecting pipe. The refrigerant exchanges heat with the indoor air and the outdoor air respectively, and the indoor unit 1 is responsible for transporting cold air or hot air into the room to achieve the effect of cooling or heating.

[0099] The indoor unit 1 may include, but is not limited to, a duct unit, a wall-mounted indoor unit, a floor-standing indoor unit, and other structural forms. Duct units are typically installed on the ceiling using a suspended ceiling and can be hidden within the ceiling. This makes them more concealed and aesthetically pleasing compared to other structural forms of indoor units 1. Furthermore, duct units utilize a decentralized air outlet, resulting in a more comfortable airflow. Specifically, referring to Figures 1 to 3 , the indoor unit 1 may include an air duct assembly 10 and a wind wheel 911.

[0100] The air duct assembly 10 is configured to construct an air duct of the indoor unit 1 for air flow. The outer contour of the air duct assembly 10 may be longitudinally long. A fan chamber 11 and a pressure diffuser chamber 12 are formed in the air duct assembly 10, and the air duct assembly 10 is further formed with a return air port 14 connected to the fan chamber 11 and an air outlet 15 connected to the heat exchange chamber 13. It is understandable that the fan chamber 11 is configured to accommodate a fan. The pressure diffuser chamber 12 is configured to receive the airflow blown from the fan chamber 11 and diffuse it to increase the pressure and flow of the airflow, thereby improving the cooling or heating effect.

[0101] The air duct assembly 10 includes a volute tongue 40, which defines a portion of the wall of the fan chamber 11 and a portion of the bottom wall of the diffuser chamber 12. The outer contour of the volute tongue 40 is curved, and may be formed, for example, by combining multiple curved segments or by combining a curved segment and a straight line, although this is not a limitation in the present embodiment.

[0102] Among them, the volute tongue 40 may include a first volute tongue portion 41 and a second volute tongue portion 42, the first volute tongue portion 41 is connected to the second volute tongue portion 42, and the structure of the two can be an integrated structure. For example, when the volute tongue 40 is made of plastic, the first volute tongue portion 41 and the second volute tongue portion 42 can be molded by injection molding, so that the connection between the two is more stable and the assembly steps between the two are reduced; of course, the structure of the two can also be a split structure, for example, connected by bonding, hot melting or snap connection.

[0103] The wind wheel 911 can be arranged in a cylindrical strip shape, and the wind wheel 911 is accommodated in the fan chamber 11. The wind wheel 911 can be a cross-flow wind wheel, a centrifugal wind wheel 911 or an axial flow wind wheel 911, etc. When the wind wheel 911 is configured as a cross-flow wind wheel, the cross-flow wind wheel has the advantages of small radial size, low rotation speed, low noise, uniform air output, etc. Its axial length can be arbitrarily lengthened without affecting the gas flow state, etc., and compared with the centrifugal wind wheel 911 or the axial flow wind wheel 911, the cross-flow wind wheel has lower cost. The wind wheel 911 can be arranged opposite to the return air port 14, so that the external airflow can flow to the wind wheel 911 through the return air port 14 in a shorter path, reducing the loss during the flow process.

[0104] During actual operation, there is a flow difference between the airflows delivered by the wind wheel 911 in different areas along its axial direction, which in turn causes a flow difference between the airflow flowing to the first volute tongue portion 41 and the airflow flowing to the second volute tongue portion 42. This will eventually cause the airflow delivered by the air outlet 15 of the indoor unit 1 to be uneven. Specifically, the airflow delivered by the area of ​​the air outlet 15 corresponding to the first volute tongue portion 41 is greater than the airflow delivered by the area of ​​the air outlet 15 corresponding to the second volute tongue portion 42, affecting the air outlet effect of the indoor unit 1. Based on this, please refer to Figures 4 to 7. In the embodiment of the present application, the second volute tongue portion 42 is arranged closer to the wind wheel 911 than the first volute tongue portion 41 in the air supply direction of the wind wheel 911, so as to reduce the flow difference between the airflow flowing to the first volute tongue portion 41 and the airflow flowing to the second volute tongue portion 42, so that the flow difference is as small as possible, or the flow difference is reduced to no flow difference. With such a setting, the embodiment of the present application has the following technical effects:

[0105] By reducing the distance between the second volute tongue portion 42 and the wind wheel 911, the amount of leakage generated by the airflow delivered by the wind wheel 911 during its flow to the second volute tongue portion 42 is reduced compared to the amount of leakage generated during its flow to the first volute tongue portion 41. This allows the flow rate of the airflow delivered by the wind wheel 911 to the volute tongue 40 to be as uniform as possible along the axial direction of the wind wheel 911. This ensures that the airflow output of the indoor unit 1 is as balanced as possible across the width of the indoor unit 1, resulting in a more uniform overall airflow effect for the indoor unit 1 and an improved user experience. Furthermore, while ensuring that the flow rates of the airflow flowing to the first volute tongue portion 41 and the airflow flowing to the second volute tongue portion 42 are as consistent as possible, a pressure difference between the airflow flowing through the first volute tongue portion 41 and the airflow flowing through the second volute tongue portion 42 is avoided, thereby reducing the occurrence of a high-flow airflow flowing into a low-flow airflow. This also reduces the generation of vortices, thereby effectively reducing noise within the indoor unit 1.

[0106] 1 to 3 , in some embodiments, the indoor unit 1 further includes a heat exchanger 92 and an electrical control box 93. A heat exchange chamber 13 is formed in the air duct assembly 10, and the fan chamber 11, the diffuser chamber 12, and the heat exchange chamber 13 are sequentially connected.

[0107] The heat exchanger 92 can have a variety of shapes, including straight, V-shaped, curved, or wavy. The heat exchanger 92 is housed within the heat exchange chamber 13 and configured to exchange heat with the gas flowing through the heat exchange chamber 13 and passing through the heat exchanger 92, thereby cooling or heating the gas. For example, multiple refrigerant pipes are provided within the heat exchanger 92. As the gas passes through the heat exchanger 92, it exchanges heat with the refrigerant within the pipes, thereby changing the gas temperature. Specifically, during cooling, the gas exchanges heat with the refrigerant in the heat exchanger 92 to form low-temperature air; while during heating, the gas exchanges heat with the refrigerant in the heat exchanger 92 to form heated air.

[0108] The electrical control box 93 can be mounted on the surface of the air duct assembly 10 to achieve fixed installation. The electrical control box 93 can be electrically connected to the fan motor and heat exchanger 92 respectively to control or regulate the fan and heat exchanger 92. For example, when the temperature in the environment where the ducted air conditioner is operating reaches a set value, the electrical control box 93 can send a command to shut down the motor and heat exchanger 92, thereby reducing energy consumption and preventing the indoor temperature from being too low or too high.

[0109] The air duct assembly 10 includes a first shell 20 and a second shell 30. The first shell 20 and the second shell 30 cooperate to define a connected diffuser chamber 12, a fan chamber 11, and a heat exchange chamber 13. The first shell 20 and the second shell 30 can be made of alloys or metals such as aluminum or steel to meet requirements such as structural strength and long service life. Of course, the first shell 20 and the second shell 30 can also be made of plastic to meet requirements such as light weight, and this application does not impose any restrictions on this. Of course, it is also possible to use a combination of one of the first shell 20 and the second shell 30 using an alloy or metal material and the other using a plastic material.

[0110] It should be noted that the first shell 20 and the second shell 30 can serve as a shell, so there is no need to set up additional structures such as other shells, thereby reducing the number of structures of the air duct assembly 10 and reducing the volume of the air duct assembly 10, thereby miniaturizing the duct unit to adapt to more use environments with relatively compact installation space. Of course, in other embodiments, the indoor unit 1 may also include a shell, which can be configured to cover the outer surfaces of the first shell 20, the second shell 30, and the side panel 22, leaving only the air outlet 15 and the return air outlet 14 exposed for communication with the outside world, thereby protecting the first shell 20, the second shell 30, and the side panel 22.

[0111] The first shell 20 may include an upper cover 21 and two side panels 22, the two side panels 22 are connected to opposite sides of the upper cover 21 along its width direction, the upper cover 21 includes a fan chamber shell 211, a diffuser chamber top shell 212 and a heat exchange chamber 13 top shell connected in sequence, and the second shell 30 includes a connected volute tongue 40, a diffuser chamber bottom shell 50 and a water receiving tray 60, and the opposite sides of the diffuser chamber bottom shell 50 are respectively connected to the volute tongue 40 and the water receiving tray 60.

[0112] The fan chamber shell 211 of the first housing 20 defines the fan chamber 11, and the diffuser chamber top shell 212 of the first housing 20 cooperates with the first volute tongue portion 41, the second volute tongue portion 42, and the diffuser chamber bottom shell 50 to define the diffuser chamber 12. Furthermore, the fan chamber shell 211, the diffuser chamber top shell 212, and the heat exchange chamber upper shell 213 can be an integrated structure to improve the connection strength of the three and reduce the number of assembly steps.

[0113] The water tray 60 is located below the heat exchanger 92 and is configured to receive condensed water flowing out of the heat exchanger 92. It cooperates with the heat exchange chamber upper shell 213 of the first housing 20 to define the heat exchange chamber 13. Furthermore, the diffuser chamber bottom shell 50 and the water tray 60 can be an integrated structure, making the connection between the two more secure and reducing assembly steps to improve assembly efficiency. Of course, in other structural forms, the diffuser chamber bottom shell 50 and the water tray 60 can be separate structures, and the two can be secured via a snap-fit ​​connection or a threaded connection, which is not limited in this application.

[0114] Furthermore, the electrical control box 93 can be installed on the surface of the diffusion chamber top shell 212 of the second shell 30 facing away from the diffusion chamber 12, and be arranged adjacent to the return air outlet 14 and facing the return air outlet 14. In this way, maintenance personnel can directly disassemble and assemble the electrical control box 93 at a position adjacent to the return air outlet 14. Since there is no other structure blocking the area adjacent to the return air outlet 14, it is more convenient for maintenance personnel to operate when disassembling and assembling the electrical control box 93.

[0115] Referring to Figure 3, in some embodiments, the housing further includes an insulation layer, specifically a first insulation layer 80 and a second insulation layer 81. The first insulation layer 80 is disposed on the surface of the top shell of the heat exchange chamber 13 facing the interior of the heat exchange chamber 13, while the second insulation layer 81 is disposed on the outer surface of the water receiving pan 60. To protect the second insulation layer 81, the housing further includes a sheet metal member attached to the exterior of the water receiving pan 60 by bolting or other means, with the second insulation layer 81 sandwiched between the sheet metal member and the water receiving pan 60. The insulation layer may be an insulating sponge, foam, or insulating glue. The provision of the insulation layer can help maintain the temperature within the air duct assembly 10 to a certain extent, reducing the probability of energy within the indoor unit 1 being dissipated outward through the first housing 20 and the second housing 30. It can also effectively isolate external noise and abnormal sounds and dampen the propagation of internal noise, thereby protecting internal components from external noise interference and improving the stability and reliability of the entire system.

[0116] Referring to Figure 4 , in some embodiments, there are two second volute tongue portions 42, connected to opposite ends of the first volute tongue portion 41. Taking the impeller 911 as an example, when the indoor unit 1 is operating under high back pressure, the eccentric vortex strength along the axial direction of the impeller is inconsistent. Specifically, the eccentric vortex located in the middle of the impeller along its axial direction is stronger and more stable, while the eccentric vortices located on both sides of the impeller along its axial direction are weaker and less stable. This results in a flow difference between the airflow delivered by the impeller and the first volute tongue portion 41 and the two second volute tongue portions 42. Accordingly, the two second volute tongue portions 42 are positioned closer to the impeller 911 than the first volute tongue portion 41. This reduces the flow difference between the airflow flowing toward the first volute tongue portion 41 and the airflow flowing toward the two second volute tongue portions 42, thereby achieving a uniform airflow output from the indoor unit 1 and reducing noise.

[0117] In some embodiments, the strength and stability of the eccentric vortices on either side of the crossflow rotor along its axial direction may also vary. Based on this, the distances between each second volute tongue portion 42 and the rotor 911 can be set to be unequal. That is, when the eccentric vortex on one side of the crossflow rotor along its axial direction is relatively strong, the corresponding distance between the second volute tongue portion 42 and the rotor 911 will be larger, while when the eccentric vortex on one side of the crossflow rotor along its axial direction is relatively weak, the corresponding distance between the second volute tongue portion 42 and the rotor 911 will be smaller. In this way, the flow rate difference between the airflows flowing to the two second volute tongue portions 42 can be reduced, thereby achieving a uniform airflow effect from the indoor unit 1 and reducing noise generation.

[0118] Please refer to Figures 15 to 7. Optionally, when the strength and stability of the eccentric vortices on both sides of the cross-flow wind wheel along its axial direction are consistent or nearly consistent, the embodiment of the present application can also be set to have the same spacing between each second volute tongue portion 42 and the wind wheel 911 in the air supply direction of the wind wheel 911.

[0119] During actual operation, the eccentric vortex located in the middle of the crossflow impeller along its axial direction may be weaker and less stable, while the eccentric vortices located on both sides of the crossflow impeller along its axial direction may be stronger and more stable. Based on this, in some embodiments, there are two first volute tongue portions 41, and the two first volute tongue portions 41 are connected to opposite ends of the second volute tongue portion 42. In this way, the distance between the second volute tongue portion 42 disposed between the two first volute tongue portions 41 and the impeller 911 can be shortened, reducing the flow difference between the airflow flowing to the first volute tongue portion 41 and the airflow flowing to the two second volute tongue portions 42, thereby making the airflow of the indoor unit 1 uniform and reducing noise generation.

[0120] Furthermore, the strength and stability of the eccentric vortices on either side of the crossflow rotor along its axial direction may also vary. Based on this, the spacing between each first volute tongue portion 41 and the rotor 911 can be set to be unequal. That is, when the eccentric vortex on one side of the crossflow rotor along its axial direction is relatively strong, the corresponding spacing between the first volute tongue portion 41 and the rotor 911 will be larger, while when the eccentric vortex on one side of the crossflow rotor along its axial direction is relatively weak, the corresponding spacing between the first volute tongue portion 41 and the rotor 911 will be smaller. In this way, the flow rate difference between the airflows flowing into the two first volute tongue portions 41 can be reduced, thereby achieving a uniform airflow effect from the indoor unit 1 and reducing noise generation.

[0121] Optionally, when the strength and stability of the eccentric vortices on both sides of the crossflow wind wheel along its axial direction are consistent or nearly consistent, the embodiment of the present application can also be set to have the same spacing from each first volute tongue portion 41 to the wind wheel 911 in the air supply direction of the wind wheel 911.

[0122] Referring to Figures 8 to 10 , in some configurations, the first tongue portion 41 is provided with a plurality of spaced-apart first guide ribs 411. Adjacent first guide ribs 411 cooperate with the first tongue portion 41 to define a first guide groove 412. Thus, the airflow delivered by the impeller 911 is guided by the first guide groove 412 and flows toward the diffuser chamber 12. This allows the noisy airflow to be separated by the first guide ribs 411 as it flows through the tongue 40, thereby attenuating the noise's energy, reducing its impact on the user, and minimizing noise generation, thereby improving the user experience. In addition, the arrangement direction of the multiple first guide ribs 411 is parallel to the axial direction of the wind wheel 911, and the extension direction of the first guide ribs 411 is perpendicular to the axial direction of the wind wheel 911 and parallel to the front and rear direction of the indoor unit 1. In this way, under the guiding effect of the multiple first guide ribs 411, the flow of airflow in the axial direction can be reduced, thereby reducing the energy loss of the airflow during the flow process toward the air outlet 15.

[0123] The second volute tongue portion 42 is provided with a plurality of second guide ribs 441 arranged at intervals, and a second guide groove 422 is defined between two adjacent second guide ribs 441 and the second volute tongue portion 42; thus, the airflow delivered by the wind wheel 911 will flow toward the diffuser chamber 12 after being guided by the second guide groove 422.

[0124] In this way, when the noisy airflow flows through the volute 40, it will be separated by the second guide ribs 441, 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 user experience. In addition, the arrangement direction of the multiple second guide ribs 441 is parallel to the axial direction of the wind wheel 911, and the extension direction of the second guide ribs 441 is perpendicular to the axial direction of the wind wheel 911 and parallel to the front-to-back direction of the indoor unit 1. In this way, under the guiding effect of the multiple second guide ribs 441, the flow of air in the axial direction can be reduced, thereby reducing the energy loss of the airflow during the flow toward the air outlet 15.

[0125] Among them, in the air supply direction of the wind wheel 911, the second guide groove 422 is arranged closer to the wind wheel 911 than the second guide groove 422, so as to reduce the air volume difference between the wind flowing toward the second guide groove 422 and the wind flowing toward the second guide groove 422.

[0126] In some structural forms, the connection between the first volute tongue portion 41 and the second volute tongue portion 42 can be configured with a smooth transition. In this way, when air flows through the connection between the first volute tongue portion 41 and the second volute tongue portion 42, the smooth transition connection has less resistance to the airflow, allowing the airflow to flow more smoothly and reducing noise caused by friction between the first volute tongue portion 41 and the second volute tongue portion 42.

[0127] In other optional structural forms, as shown in Figures 9 and 10, the connection between the first and second volute tongue portions 41, 42 can be arranged in a stepped transition. This step-like arrangement can optimize the pressure distribution of the airflow over the entire volute tongue 40, with one portion distributed on the first volute tongue portion 41 and the other on the second volute tongue portion 42. This can reduce the impact of the airflow on the entire volute tongue 40, thereby reducing noise generation.

[0128] Second embodiment

[0129] The present embodiment provides an indoor unit 1. Optionally, the indoor unit 1 may be a ducted unit. The indoor unit 1 is connected to an outdoor unit via cables, pipes, etc., so that the indoor unit 1 and the outdoor unit can work together to regulate the indoor environment. It is understood that the indoor unit 1 can be installed indoors in a form such as a suspended ceiling and configured to supply air to the room.

[0130] In the present application, a vertical direction ZZ, a front-rear direction YY, and a left-right direction XX are defined, and the vertical direction ZZ, the front-rear direction YY, and the left-right direction XX are arranged to form an angle between each other.

[0131] 11 and 12 , in the embodiment of the present application, the indoor unit 1 includes an air duct assembly 10 , a fan 91 , a heat exchanger 92 and an electric control box 93 .

[0132] The air duct assembly 10 is configured to be configured as an air duct of the indoor unit 1 for gas flow. Specifically, the air duct assembly 10 is a structure mainly composed of a shell, and the outer contour of the air duct assembly 10 can be roughly rectangular. Referring to Figures 12 to 14, the air duct assembly 10 includes a first shell 20 and a second shell 30 connected to each other. The first shell 20 and the second shell 30 define a fan chamber 11, a pressure diffuser chamber 12 and a heat exchange chamber 13 that are connected in sequence, and are formed with a return air port 14 connected to the fan chamber 11 and an air outlet 15 connected to the heat exchange chamber 13, so that the gas can enter the air duct assembly 10 from the return air port 14, and pass through the fan chamber 11, the pressure diffuser chamber 12 and the heat exchange chamber 13 in sequence, and finally flow out from the air outlet 15.

[0133] The first shell 20 and the second shell 30 can each be made of a metal material such as aluminum alloy or stainless steel to meet requirements such as high strength and corrosion resistance; alternatively, the first shell 20 and the second shell 30 can also be made of a plastic material to achieve lightweighting of the air duct assembly 10, and this application does not impose any restrictions on this. For example, the air duct assembly 10 can be a combination of a first shell 20 made of metal and a second shell 30 made of plastic. In addition, the embodiments of this application do not limit the connection method of the first shell 20 and the second shell 30. They can be connected individually or in combination through methods such as clamping, riveting, welding, and bolting.

[0134] Referring to Figures 12 and 14 , the first housing 20 includes an upper cover 21 and two side panels 22. The two side panels 22 are spaced apart in the left-right direction. The upper cover 21 is generally positioned above the two side panels 22 and connected to the two side panels 22 on either side of the upper cover 21. From back to front, the upper cover 21 includes a fan chamber housing 211, a diffuser chamber top housing 213, and a heat exchange chamber top housing 213, which are connected in sequence. The second housing 30 is spaced apart from the upper cover 21 in the vertical direction and includes a connected guide plate 52, a volute 40, a diffuser chamber bottom housing 50, and a water collection tray 60. The volute 40 is located at the transition between the fan chamber 11 and the diffuser 12. The guide plate 52 is located below the volute 40 to guide the airflow below the volute 40. The diffuser chamber bottom housing 50 is located in front of the volute 40, and the end of the diffuser chamber bottom housing 50 away from the volute 40 is connected to the water collection tray 60. The fan chamber shell 211 at least defines the fan chamber 11 together with the guide plate 52 and the side panel 22, the diffuser chamber top shell 213 at least defines the diffuser chamber 12 together with the diffuser chamber bottom shell 50 and the side panel 22, and the heat exchange chamber top shell 213 defines the heat exchange chamber 13 together with the water receiving tray 60 and the side panel 22.

[0135] Continuing to refer to Figures 12 and 14, the air duct assembly 10 also includes a grille 98 provided at the return air outlet 14, and the grille 98 connects the guide plate 52 and the fan chamber shell 211. A plurality of through holes are formed on the grille 98, and gas can enter the fan chamber 11 through the plurality of through holes. The provision of the grille 98 can effectively prevent larger foreign matter from entering the fan chamber 11 and affecting the operation of the fan 91. The grille 98 is arranged in a grid shape to increase the through holes as much as possible and reduce the impact on the airflow. Optionally, the grille 98 as a whole can be arranged in an arc shape, or the grille 98 can be formed by connecting two grille 98 plate sections arranged at an angle.

[0136] The fan 91 is arranged in the fan chamber 11 and is capable of extracting gas from the return air inlet 14 and performing work on it so that it flows to the diffuser chamber 12 at a faster flow rate, thereby providing power for the gas circulation in the above-mentioned air duct. The fan 91 can be a cross-flow fan, a centrifugal fan, an axial flow fan, etc. As shown in Figure 15, taking a cross-flow fan as an example, the fan 91 includes a wind wheel 911 and a motor 913. The wind wheel 911 is arranged in a long cylindrical shape. The motor 913 is arranged at one end of the wind wheel 911 and connected to the side panel 22, and the output shaft of the motor 913 is connected to the wind wheel 911. One side of the wind wheel 911 is arranged generally toward the return air inlet 14, and this side of the wind wheel 911 is defined as the air inlet side 91a; the other side of the wind wheel 911 is arranged generally toward the diffuser chamber 12, and this side of the wind wheel 911 is defined as the air outlet side 91b. A plurality of blades are distributed along the circumference of the wind wheel 911. When the motor 913 drives the wind wheel 911 to rotate, the rotating blades can cause the air to flow from the air inlet side 91a to the air outlet side 91b. The cross-flow fan has the advantages of energy saving, large air volume, low noise and simple installation.

[0137] 14 , the heat exchanger 92 is housed within the heat exchange chamber 13 and is configured to exchange heat with the gas flowing through the heat exchange chamber 13 and passing through the heat exchanger 92, thereby cooling or heating the gas. For example, multiple refrigerant pipes are provided within the heat exchanger 92. As the gas passes through the heat exchanger 92, it exchanges heat with the refrigerant within the pipes, thereby lowering its temperature and forming low-temperature air. Optionally, the heat exchanger 92 can be configured in a convex, curved, or wavy shape and can be composed of a single heat exchange fin or a combination of multiple heat exchange fins.

[0138] The electrical control box 93 is provided with an electrical control board assembly, which integrates a variety of electronic components. The electrical control board assembly is configured to be electrically connected to devices such as the fan 91 and is configured to provide overall control over the overall operating status of the indoor unit 1. Inevitably, electronic components generate a considerable amount of heat during operation. In the embodiment of the present application, the electrical control box 93 can be disposed within the air duct formed by the air duct assembly 10, or disposed close to the air duct, so that the airflow within the air duct can dissipate a certain degree of heat from the electrical control box 93, thereby avoiding component operational failures or damage caused by overheating of the electrical control board assembly, improving the operational stability of the indoor unit 1, and extending its service life.

[0139] In some embodiments of the present application, when the indoor unit 1 is in operation, the motor 913 rotates the impeller 911, and air flows out from the outlet side 91b of the impeller 911. The volute tongue 40 is arranged near the outlet side 91b of the impeller 911 and is configured to guide the airflow on the outlet side 91b. Specifically, referring to FIG16 , the volute tongue 40 has a windward surface 43a, a wind guide surface 43b, and a transition surface 43c. The windward surface 43a is arranged toward the outlet side 91b of the impeller 911 and is spaced apart from the impeller 911. The wind guide surface 43b extends approximately in a direction away from the impeller 911 relative to the windward surface 43a and is arranged at an angle to the windward surface 43a. It should be noted that the wind guide surface 43b and the windward surface 43a can be curved or flat. For example, the windward surface 43a extends generally in the vertical direction, and the wind-guiding surface 43b extends generally in the front-to-back direction. If both wind-guiding surface 43b and windward surface 43a are planes, the plane of wind-guiding surface 43b intersects and forms an angle with the plane of windward surface 43a. Alternatively, if at least one of wind-guiding surface 43b and windward surface 43a is curved, the extension direction of wind-guiding surface 43b intersects and forms an angle with the extension direction of windward surface 43a. The transition surface 43c connects the windward surface 43a and the wind-guiding surface 43b and is configured to direct a portion of the airflow directed toward the transition surface 43c toward the windward surface 43a and a portion toward the wind-guiding surface 43b. In this way, the volute tongue 40 effectively guides the airflow, reducing or preventing gas circulation within the air duct and improving efficiency. Optionally, the transition surface 43c is arranged in an arc shape and is smoothly connected to the windward surface 43a and the wind guiding surface 43b, so that the airflow flowing toward the windward surface 43a and the wind guiding surface 43b is smoother.

[0140] In one embodiment, the windward surface 43a is an arc surface that arches away from the wind wheel 911, so that the windward surface 43a fits more closely to the shape of the outer contour of the wind wheel 911, so that the airflow flow area between the windward surface 43a and the wind wheel 911 is more abundant, which facilitates airflow circulation and improves airflow stability.

[0141] Combining Figures 14 and 16 , it can be understood that a greater amount of airflow is directed toward the wind guide surface 43b, while the transition surface 43c is strongly impacted by the airflow. This results in a higher level of airflow noise near the tongue 40, significantly impacting the user experience. To address this issue, in the embodiment of the present application, the transition surface 43c includes a sunken area 43c1. This sunken area 43c1 is located in the section of the transition surface 43c near the wind guide surface 43b and is recessed toward the wind guide surface 43b. Taking the wind guide surface 43b as a plane, the wind guide surface 43b is extended toward the transition surface 43c. The sunken area is lowered in the vertical direction relative to the extended portion of the wind guide surface 43b. This reduces the height of the sunken area 43c1 relative to the rotor 911. In the embodiment of the present application, the sunken area 43c1 is recessed, which reduces the thickness of the tongue 40 near the rotor 911 to a certain extent, allowing the airflow on the outlet side 91b of the rotor 911 to be more easily diverted, thereby improving efficiency. Providing the sinking area 43c1 can also reduce the angle between the surface of the sinking area 43c1 and the direction of the airflow. The airflow flowing to the wind guide surface 43b is closer to the surface of the sinking area 43c1, the airflow is smoother and the impact on the volute tongue 40 is reduced, and the noise generated is smaller, thereby reducing the overall noise of the indoor unit 1 and improving the user experience.

[0142] The sunken area 43c1 has a boundary with both the windward surface 43a and the wind-guiding surface 43b. To ensure smoother airflow, the boundary between the sunken area 43c1, the windward surface 43a, and the wind-guiding surface 43b is smoothly transitioned. In one embodiment, the boundary between the sunken area 43c1 and the wind-guiding surface 43b is located further away from the wind wheel 911 than the boundary between the sunken area 43c1 and the windward surface 43a. Thus, when observing the volute tongue 40 from a direction perpendicular to the wind-guiding surface 43b, at least a portion of the sunken area 43c1 can be observed. The sunken area 43c1 extends further toward the wind-guiding surface 43b, facilitating continuous guidance of the airflow toward the wind-guiding surface 43b. This effectively reduces the impact of the airflow on the volute tongue 40, allowing the airflow to transition more smoothly to the wind-guiding surface 43b, and further reducing aerodynamic noise.

[0143] Optionally, the sinking area 43c1 can be a sloped surface with one or more sections, that is, the sinking area 43c1 is projected along the axial direction of the wind wheel 911, and the projected outline is an inclined straight line, or multiple straight lines that are connected and bent to each other. In this way, the volute tongue 40 can guide the airflow while having a simpler structure and is easier to form.

[0144] As shown in Figure 16 , in one embodiment, the sunken area 43c1 is an arcuate surface that rises toward the wind guide surface 43b. That is, when the sunken area 43c1 is projected along the axial direction of the impeller 911, the projected outline is roughly an arc. The arcuate design of the sunken area 43c1 better aligns with the flow of air above the sunken area 43c1, helping to guide the airflow in its direction, allowing it to flow more smoothly to the wind guide surface 43b, further improving the air flow and reducing noise.

[0145] It is understood that in some indoor units 1, such as duct units, the impeller 911 has a rotating shaft extending along the left-right direction XX. The impeller 911 is relatively long along an axial direction parallel to the left-right direction XX, and the volute tongue 40 is arranged along the axial direction of the impeller 911. The sunken area 43c1 may also extend along the axial direction of the impeller 911. To comprehensively reduce the impact of airflow on the volute tongue 40, the sunken area 43c1 may occupy as much area of ​​the volute tongue 40 as possible along the axial direction of the impeller 911. For example, the entire section of the transition surface 43c along the axial direction of the impeller 911 may be configured as the sunken area 43c1.

[0146] Referring again to FIG. 15 , in other embodiments, the transition surface 43c is further provided with a raised area 43c2 along the extension direction of the volute tongue 40 (left-right direction XX). The raised area 43c2 is raised in a direction away from the wind-guiding surface 43b and smoothly transitions to the sunken area 43c1. With the raised area 43c2 as a reference, the height of the sunken area 43c1 along the vertical direction ZZ is lower than that of the raised area 43c2. When the airflow above the transition surface 43c flows through the raised area 43c2 and the sunken area 43c1, the airflow velocity is different, and thus the time required for the airflow to flow is different. The airflow will not strike the transition surface 43c at the same time, resulting in a certain phase difference in the noise, avoiding the resonant noise caused by the superposition of noises of the same frequency, effectively reducing the overall noise peak, and improving the overall noise effect of the fan 91, thereby improving the user experience.

[0147] Referring to Figure 15 , in a specific embodiment, a sinking area 43c1 is provided in the middle of the volute tongue 40 and extends toward both ends of the volute tongue 40. Along the left-right direction XX, when the fan 91 is operating, the middle portion of the airflow flowing through the volute tongue 40 has a larger airflow rate, while the airflow rate at the two ends is smaller. The uneven distribution of airflow along the extension direction of the volute tongue 40 may cause vortices to form, thereby affecting aerodynamic performance, reducing the flow efficiency of the airflow, and causing noise. In the embodiment of the present application, by providing the sinking area 43c1 in the middle of the volute tongue 40, the airflow with a larger flow rate in the middle of the volute tongue 40 can be effectively guided and transitioned. The arched areas 43c2 provided at both ends of the volute tongue 40 can increase the flow rate and flow rate of the airflow to a certain extent, making the axial distribution of the airflow more uniform, improving aerodynamic performance, and reducing noise.

[0148] Continuing with FIG. 15 , in one embodiment, the volute tongue 40 has a width perpendicular to its extension direction. The volute tongue 40 extends in the left-right direction XX, and its width is generally aligned with the front-back direction YY. The width of the sunken area 43c1 along the width direction YY gradually decreases from the center of the volute tongue 40 toward its ends. It is understood that the longer the width of the sunken area 43c1, the more consistently it reduces the impact of airflow on the volute tongue 40. Along the extension direction of the volute tongue 40, the airflow is generally distributed with a higher flow rate in the center and a lower flow rate at the sides. The larger width of the sunken area 43c1 in the center facilitates effective guidance of the higher flow rate, while the width of the sunken area 43c1 gradually decreases toward the ends of the volute tongue 40. This ensures effective airflow guidance and reduces noise while also achieving more uniform airflow distribution and ensuring aerodynamic performance.

[0149] In some embodiments, because the arched area 43c2 is higher than the sunken area 43c1, and the sunken area 43c1 smoothly transitions to the arched areas 43c2 at both ends, the height of the sunken area 43c1 gradually increases from the middle to the ends of the volute tongue 40 until it is at least flush with the arched area 43c2. The gradual reduction in width not only makes the transition between the sunken area 43c1 and the arched area 43c2 smoother, reducing airflow disturbances, but also further increases the flow rate and volume of the airflow on both sides, making the airflow more uniform and stable.

[0150] Furthermore, in one embodiment, the distance between the sunken area 43c1 and the wind wheel 911 gradually decreases from the middle of the volute tongue 40 to the ends of the volute tongue 40. Increasing the distance between the volute tongue 40 and the wind wheel 911 can effectively reduce the impact of airflow on the volute tongue 40, thereby reducing noise. It can be understood that the gradually decreasing distance between the sunken area 43c1 and the wind wheel 911 from the middle to the ends can gradually increase the airflow on both sides to a certain extent, thereby further optimizing the distribution of airflow along the extension direction of the volute tongue 40, making it more uniform and stable, improving air output reliability, and further reducing overall noise, thereby enhancing the user experience.

[0151] The volute tongue 40 is defined as having a centerline perpendicular to its extension direction (left-right direction), extending generally along the front-to-back direction YY. During operation of the indoor unit 1, the airflow distribution above the volute tongue 40 is roughly symmetrical about this centerline. In one embodiment, the sunken area 43c1 is symmetrically arranged about this centerline to achieve a symmetrical airflow distribution near the volute tongue 40, thereby achieving a symmetrical airflow guidance effect, conforming to the airflow, improving guidance efficiency, and further reducing noise.

[0152] Please refer to Figures 17 and 18. In order to further improve the airflow noise, in some embodiments, the volute tongue 40 further includes a plurality of guide ribs 44. The guide ribs 44 are in the shape of long strips and are protruded from the outer surface of the volute tongue 40 at intervals along the axial direction of the wind wheel 911. The guide ribs 44 are formed by integral injection molding, or fixed to the outer surface of the volute tongue 40 by bonding or snap connection. Two adjacent guide ribs 44 and the surface of the volute tongue 40 define a guide groove, which can play a role in combing and guiding the airflow. On the one hand, it can reduce the flow of wind in the axial direction, thereby reducing the pressure loss of wind in the process of flowing to the air outlet 15. On the other hand, it can also separate the wind with noise, so that the energy of the noise can be weakened. Through these two effects, the noise can be effectively reduced and the user experience can be improved.

[0153] Among them, at least a portion of the guide rib 44 is connected to the transition surface 43c, so as to be configured to guide the airflow above the transition surface 43c. Projected along the axial direction of the wind wheel 911, the guide rib 44 has a guide rib 44 profile, and the guide rib 44 profile is parallel to the surface of the sinking area 43c1. In other words, in the sinking area 43c1, the shape of the upper surface of the plurality of guide ribs 44 is also sunken, thereby also being able to reduce the impact of the airflow and further reduce the noise. It is understandable that the guide rib 44 can also extend to the wind-guiding surface 43b and the windward surface 43a, and the two ends of the guide rib 44 are smoothly connected to the wind-guiding surface 43b and the windward surface 43a to improve the wind-guiding effect and ensure a smooth transition of the airflow.

[0154] With reference to Figures 16 and 19 , in some embodiments, the volute 40 includes a volute body 43 and a support structure 45. The support structure 45 is connected to the end of the diffuser chamber bottom shell 50 away from the water receiving tray 60 and is configured to provide support for the volute body 41. The volute body 43 is disposed on the side of the support structure 45 away from the diffuser chamber bottom shell 50 and has a windward surface 43a, a transition surface 43c, and at least a portion of a wind-guiding surface 43b, configured to guide airflow. The volute body 43 is smoothly connected to the upper surface of the support structure 45, so that the wind-guiding surface 43b extends to the support structure 45, ensuring smoother airflow.

[0155] Furthermore, referring to FIG. 16 again, the volute tongue body 43 and the supporting structure 45 further enclose and form a hollow cavity 16 , which saves materials to a great extent and reduces costs while ensuring structural strength.

[0156] In the embodiment of the present application, the volute tongue body 43 and the support structure 45 can be processed and formed separately. Not only is it relatively simple to design the molds for the volute tongue body 43 and the support structure 45 separately, thereby reducing costs, but the volute tongue body 43 and the support structure 45 can also be demolded separately, making the demolding operation simple and more efficient. Among them, the volute tongue body 43 and the support structure 45 can be detachably connected by means of snaps or the like. In this way, different volute tongue bodies 43 can be selected and matched according to the specific actual use situation. When replacement is required, it is only necessary to disassemble and assemble the volute tongue body 43 from the support structure 45, making the structure more flexible and improving the structural applicability; or when the volute tongue 40 needs to be maintained, maintenance personnel can also disassemble and assemble the volute tongue body 43 from the support structure 45, improving the convenience of disassembly and maintenance.

[0157] In one embodiment, the diffuser chamber bottom shell 50 and the support structure 45 can be an integral structure. In this way, the connection strength between the diffuser chamber bottom shell 50 and the support structure 45 can be improved, and the assembly steps of the diffuser chamber bottom shell 50 and the support structure 45 can be reduced, thereby improving production efficiency. Of course, the two can also be separate structures and fixed by gluing, snap connection, etc., and this application does not limit this. Furthermore, the volute tongue body 43 and the support structure 45 are an integral structure, which is conducive to improving the structural integrity of the volute tongue 40, reducing assembly gaps, and avoiding noise caused by air leakage. Furthermore, the volute tongue 40 and the diffuser chamber bottom shell 50 are an integral structure, which can be formed by integral injection molding, and the structural integrity of the second shell 30 is stronger and the processing efficiency is higher.

[0158] The above is a specific embodiment of the volute tongue 40. On this basis, the volute tongue 40 can be configured as the air duct assembly 10 and indoor unit 1 proposed in this application. Since the air duct assembly 10 and indoor unit 1 proposed in this application adopt all the technical solutions of all the above embodiments, they at least have all the effects brought by the technical solutions of the above embodiments, which will not be described in detail here.

[0159] Third embodiment

[0160] In the related art, the indoor unit of the HVAC equipment includes an air duct assembly, and the air duct assembly is formed with a fan chamber, a pressure diffusion chamber and a heat exchange chamber that are connected in sequence. A cross-flow fan is provided in the fan chamber, and a heat exchanger is provided in the heat exchange chamber. The pressure diffusion chamber is configured to receive the airflow blown from the fan chamber and diffuse it to increase the pressure and flow of the airflow, thereby improving the cooling or heating effect.

[0161] However, the eccentric vortices at the two end positions of the cross-flow fan of the above-mentioned indoor unit are less stable than the eccentric vortex at the middle position, and the eccentric vortices at the end positions are partially located at the inlet end of the diffusion chamber, resulting in blockage of the cavity of the diffusion chamber, thereby generating excessive noise during the operation of the indoor unit, affecting the user experience.

[0162] To solve the above problems, please refer to Figure 20. The present application proposes a HVAC device. In the embodiment of the present application, the HVAC device includes but is not limited to air conditioners, multi-split units, and heat pumps, and can be used in large-scale places such as shopping malls and office buildings. Among them, the HVAC device may include an indoor unit 1, an outdoor unit (not shown in the figure) and a connecting pipe (not shown in the figure). The indoor unit 1 is connected to the outdoor unit through the connecting pipe so that the indoor unit 1 and the outdoor unit form a refrigerant cycle. In some actual use scenarios, the indoor unit 1 of the present application can be installed indoors, the outdoor unit is responsible for cooling or heating, and transports the refrigerant through the connecting pipe. The refrigerant exchanges heat with the indoor air and the outdoor air respectively, and the indoor unit 1 is responsible for transporting cold air or hot air to the room to achieve the effect of cooling or heating.

[0163] Specifically, the indoor unit 1 may include, but is not limited to, a duct unit, a wall-mounted air conditioner indoor unit 1, and a floor-standing air conditioner indoor unit 1. Duct units are typically installed on the ceiling using a suspended ceiling and can be hidden within the ceiling, making them more concealed and aesthetically pleasing compared to other indoor unit 1 structures. Furthermore, duct units utilize a decentralized air outlet, resulting in a more comfortable airflow. Referring to Figures 21 to 23 , the indoor unit 1 may include an air duct assembly 10, a fan 91, a heat exchanger 92, and an electrical control box.

[0164] The air duct assembly 10 is configured to be configured as an air duct for the indoor unit 1 to facilitate air flow. The outer contour of the air duct assembly 10 can be elongated. The air duct assembly 10 defines a fan chamber 11, a diffuser chamber 12, and a heat exchange chamber 13, which are sequentially connected. The air duct assembly 10 also defines an air return port 14 connected to the fan chamber 11 and an air outlet 15 connected to the heat exchange chamber 13.

[0165] It is understandable that the fan chamber 11 is configured to accommodate the fan 91, and the fan 91 is a cross-flow fan. The diffuser chamber 12 is configured to receive the airflow blown from the fan chamber 11 and diffuse it to increase the pressure and flow of the airflow, so as to improve the cooling or heating effect. The heat exchange chamber 13 is configured to accommodate the heat exchanger 92. In this way, the external airflow can flow in from the return air port 14 under the action of the fan, and flow through the fan chamber 11, the diffuser chamber 12 and the heat exchange chamber 13 in turn, so as to heat the heat exchanger 92 in the heat exchange chamber 13, and then flow out from the air outlet 15 to achieve heating or cooling of the external airflow.

[0166] The air duct assembly 10 includes a first shell 20 and a second shell 30. The first shell 20 and the second shell 30 cooperate to define a connected diffuser chamber 12, a fan chamber 11, and a heat exchange chamber 13. The first shell 20 and the second shell 30 can be made of alloys or metals such as aluminum or steel to meet requirements such as structural strength and long service life. Of course, the first shell 20 and the second shell 30 can also be made of plastic to meet requirements such as light weight, and this application does not impose any restrictions on this. Of course, it is also possible for one of the first shell 20 and the second shell 30 to be made of an alloy or metal material, while the other is made of plastic.

[0167] It should be noted that the first shell 20 and the second shell 30 can serve as the outer shell 90. In this way, there is no need to set up additional structures such as the outer shell 90, thereby reducing the number of structures of the air duct assembly 10 and reducing the overall volume of the indoor unit 1, thereby miniaturizing the duct unit to adapt to more use environments with relatively compact installation space. Of course, in other embodiments, the indoor unit 1 may also include an outer shell 90. The outer shell 90 can be configured to cover the outer surfaces of the first shell 20 and the second shell 30, leaving only the air outlet 15 and the return air outlet 14 exposed for communication with the outside world, thereby protecting the first shell 20 and the second shell 30.

[0168] The first shell 20 may include an upper cover 21 and two side panels 22, the two side panels 22 are connected to opposite sides of the upper cover 21 along its width direction, the upper cover 21 includes a fan chamber shell 211, a diffuser chamber top shell 212 and a heat exchange chamber top shell 213 connected in sequence, and the second shell 30 includes a connected volute tongue 40, a diffuser chamber bottom shell 50 and a water receiving tray 60, and the opposite sides of the diffuser chamber bottom shell 50 are respectively connected to the volute tongue 40 and the water receiving tray 60.

[0169] The second housing 30 includes an air inlet surface 31, a volute tongue surface 32, and a pressure diffuser surface 33, which are connected in sequence. The air inlet surface 31 is formed on the pressure diffuser chamber bottom shell 50 and is configured as a portion of the cavity wall of the fan cavity 11. The pressure diffuser surface 33 is formed on the pressure diffuser chamber bottom shell 50 and is configured as at least a portion of the cavity bottom wall of the pressure diffuser chamber 12. The volute tongue surface 32 is formed on the volute tongue 40. It can be understood that the airflow from the return air port 14 will flow into the fan 91 along the guidance of the air inlet surface 31, and the volute tongue surface 32 will guide part of the airflow delivered by the fan 91 into the pressure diffuser chamber 12, and guide part of the airflow into the gap between the volute tongue surface 32 and the fan 91 to flow back into the fan 91.

[0170] The fan chamber housing 211 of the first housing 20 and the air inlet surface 31 of the diffuser chamber bottom housing 50 define the fan chamber 11. The diffuser chamber top housing 212 of the first housing 20, the volute 40, and the diffuser surface 33 of the diffuser chamber bottom housing 50 cooperate to define the diffuser chamber 12. The water receiving tray 60 cooperates with the heat exchange chamber top housing 213 to define the heat exchange chamber 13. Furthermore, the fan chamber housing 211, the diffuser chamber top housing 212, and the upper housing of the heat exchange chamber 13 can be an integrated structure to improve the connection strength of the three and reduce the number of assembly steps.

[0171] The water tray 60 is located below the heat exchanger 92 and is configured to receive condensed water flowing out of the heat exchanger 92. It cooperates with the diffuser chamber top shell 212 of the first housing 20 to define the heat exchange chamber 13. Furthermore, the diffuser chamber bottom shell 50 and the water tray 60 can be an integral structure, making the connection more secure and reducing assembly steps to improve assembly efficiency. Of course, in other structural forms, the diffuser chamber bottom shell 50 and the water tray 60 can be separate structures, and the two can be secured via a snap-fit ​​connection or a threaded connection, which is not limited in this application.

[0172] The fan 91 is arranged in the fan cavity 11 and includes a wind wheel 911 and a motor 913. The wind wheel 911 is housed in the fan cavity 11, and the motor 913 is installed in the air duct assembly 10. The output shaft of the motor 913 is connected to the wind wheel 911 to drive the wind wheel 911 to rotate. The wind wheel 911 can be arranged in a cylindrical strip shape. The fan 91 has the advantages of small radial size, low speed, low noise, uniform air output, etc. Its axial length can be arbitrarily extended without affecting the gas flow state, etc., and compared with centrifugal fans or axial flow fans, the cost of the fan 91 is lower. The fan 91 can be arranged opposite the return air port 14 so that the external air flow can flow to the wind wheel of the fan 91 through the return air port 14 in a shorter path, reducing losses during the flow process.

[0173] The heat exchanger 92 can have a variety of shapes, including straight, V-shaped, curved, or wavy. The heat exchanger 92 is configured to exchange heat with the gas flowing through the heat exchange chamber 13 and passing through the heat exchanger 92, thereby cooling or heating the gas. For example, a plurality of refrigerant pipes are provided within the heat exchanger 92. As the gas passes through the heat exchanger 92, it exchanges heat with the refrigerant within the pipes, thereby changing the gas temperature. Specifically, during cooling, the gas exchanges heat with the refrigerant in the heat exchanger 92 to form low-temperature air; while during heating, the gas exchanges heat with the refrigerant in the heat exchanger 92 to form heated air.

[0174] The electrical control box 93 can be mounted on the surface of the air duct assembly 10 to achieve fixed installation. The electrical control box 93 can be electrically connected to the motor of the fan 91 and the heat exchanger 92, respectively, to control or regulate the fan 91 and the heat exchanger 92. For example, when the temperature in the environment where the duct unit is operating reaches a set value, the electrical control box 93 can send a command to shut down the motor and heat exchanger 92, thereby reducing energy consumption and preventing the indoor temperature from being too low or too high.

[0175] Furthermore, the electrical control box 93 can be installed on the surface of the air duct assembly 10 away from the diffuser chamber 12, and be adjacent to the return air outlet 14 and arranged toward the return air outlet 14. In this way, maintenance personnel can directly disassemble and assemble the electrical control box 93 at a position adjacent to the return air outlet 14. Since there is no other structure blocking the area adjacent to the return air outlet 14, it is more convenient for maintenance personnel to operate when disassembling and assembling the electrical control box 93.

[0176] The indoor unit 1 may further include a grille 70, which may be installed at the return air inlet 14. The grille 70 prevents users or maintenance personnel from touching the impeller of the fan 91, thereby reducing the risk of injury from accidentally touching the impeller blades. Furthermore, the grille 70 blocks external debris, preventing it from entering the fan chamber 10a and heat exchange chamber 13 of the fan 91 and potentially affecting the impeller of the fan 91 and the heat exchanger 92. This can extend the service life of the indoor unit 1.

[0177] Please refer to Figures 23 to 26. In some embodiments, a shoulder 34 is provided at the end of the air inlet surface 31 along the axial direction of the fan 91. The shoulder 34 engages the volute tongue surface 32. The shoulder 34 is provided to protrude toward the fan 91 relative to the air inlet surface 31. It is understood that in the radial direction of the fan 91, the distance between the shoulder 34 and the outer circumference of the fan 91 is smaller than the distance between the air inlet surface 31 and the outer circumference of the fan 91. As a result, the indoor unit 1 of the embodiment of the present application has at least the following technical effects:

[0178] By providing a shoulder 34 at the end position of the air inlet surface 31, and the shoulder 34 being able to cooperate with the volute tongue surface 32 connected thereto, the positions of the eccentric vortices located on both sides of the fan 91 can be controlled as much as possible between the volute tongue surface 32 and the fan 91, and between the shoulder 34 and the fan 91, thereby reducing the possibility that the eccentric vortices on both sides of the fan 91 are located at the inlet end of the diffuser chamber 12. In this way, the effective flow area at the inlet end of the diffuser chamber 12 can be effectively increased, and the cavity blockage of the diffuser chamber 12 can be reduced, thereby reducing the phenomenon of air flow backflow when the air flow flows through the diffuser chamber 12, thereby effectively alleviating the surge phenomenon of the indoor unit 1, and reducing the overall noise and vibration of the indoor unit 1.

[0179] In addition, the setting of the shoulder 34 can also improve the stability of the eccentric vortices on both sides of the fan 91. Specifically, with the setting of the shoulder 34, the airflow flowing in from the gap between the volute tongue surface 32 and the fan 91 will increase the drainage effect of the shoulder 34 on the basis of the drainage of the volute tongue surface 32, and appropriately reduce the flow rate of the airflow, so that the airflow does not directly impact the eccentric vortices on both sides of the through-flow wind wheel on the basis of a large flow rate, so as to improve the stability of the eccentric vortex. Furthermore, on the basis of the improved stability of the eccentric vortex, the stability of the airflow delivered by the two sides of the fan 91 is improved, and the outflow is stable, so that the pressure fluctuation of the airflow on the volute tongue surface 32 is reduced, so as to effectively achieve noise reduction.

[0180] Please refer to Figures 27 and 28. In some embodiments, the side of the shoulder 34 facing the fan 91 includes a first surface 341 and a second surface 343 arranged at an angle. The first surface 341 is connected between the volute tongue surface 32 and the second surface 343, and the second surface 343 extends along the extension direction of the air inlet surface 31. The extension length of the first surface 341 is less than the extension length of the second surface 343 (as shown in Figure 23). It can be understood that the airflow from the return air outlet 14 will also be guided along the second surface 343 to flow into the fan 91. The volute tongue surface 32 located at the axial upper end of the volute tongue 40 of the fan 91 will cooperate with the first surface 341 to guide part of the airflow sent out by the fan 91 to the gap between the volute tongue surface 32 and the fan 91 so that it can flow back into the fan 91.

[0181] On the basis that the extension length of the first surface 341 is less than the extension length of the second surface 343, the distance between the eccentric vortex controlled between the first surface 341 and the fan 91 and the return air outlet 14 is relatively far, so that the eccentric vortex does not occupy too much of the return air outlet 14, thereby increasing the effective flow area of ​​the return air outlet 14. If the extension length of the first surface 341 is greater than or less than the extension length of the second surface 343, the connection between the first surface 341 and the second surface 343 will be too close to the position of the return air outlet 14, causing the eccentric vortex controlled between the first surface 341 and the fan 91 to be too close to the position of the return air outlet 14, thereby causing the eccentric vortex to occupy too much of the return air outlet 14, causing blockage, reducing the effective flow area of ​​the return air outlet 14, and affecting the flow rate of the airflow flowing in from the return air outlet 14. Of course, in other embodiments, the extension length of the first surface 341 can also be less than or equal to the extension length of the second surface 343, and this application does not limit this.

[0182] Please refer to Figures 23 to 26. Further, in the longitudinal section of the indoor unit 1 along the airflow direction, the center of the fan 91 is defined as O, the connection point between the volute tongue surface 32 and the diffuser surface 33 is A, the connection point between the volute tongue surface 32 and the air inlet surface 31 is B, and the connection point between the first surface 341 and the second surface 343 is C.

[0183] The angle between the line L0 passing through points O and A and the line L1 passing through points O and B is α, and the angle between the line L0 passing through points O and A and the line L2 passing through points O and C is β. Among them, the following conditions are met: α minus β must be greater than or equal to 5 degrees, and must be less than or equal to 30 degrees. In this way, the position of some eccentric vortices on both sides of the fan 91 can be controlled between the shoulder 34 and the fan 91, and the stability of some eccentric vortices on both sides of the fan 91 can be increased while avoiding the situation where too many eccentric vortices occupy the return air port 14 and cause blockage, thereby effectively increasing the effective flow area of ​​the return air port 14. If α minus β is less than 5 degrees, the position of some eccentric vortices on both sides of the fan 91 cannot be well controlled, and the phenomenon of eccentric vortices being located at the inlet end of the diffuser chamber 12 will still exist. If α minus β is greater than 30 degrees, the first surface 341 will be too close to the return air port 14, which will cause the eccentric vortex to occupy the return air port 14. For example, α minus β can be 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, or 30 degrees, etc. Of course, in other embodiments, α minus β can also be less than 5 degrees, or α minus β can be greater than 30 degrees, and this application does not limit this.

[0184] Referring to Figures 23 and 24 , the first surface 341 extends vertically downward in the height direction of the indoor unit 1, and the angle β formed with the second surface 343 is greater than 0 degrees and less than 60 degrees. This reduces the noise generated by the fan 91 during operation while also reducing the noise generated by the second surface 343 of the shoulder 34 and the fan 91. If β is less than 0 degrees, the second surface 343 will be too close to the fan 91, resulting in excessive interference between the fan 91 and the second surface 343, increasing noise. If β is greater than 60 degrees, the second surface 343 surrounding the return air outlet 14 will be too far away from the fan housing 211, resulting in an excessively large opening area of ​​the return air outlet 14, which in turn causes excessive noise generated by the fan 91 during operation. For example, β can be 0 degrees, 10 degrees, 20 degrees, 30 degrees, 40 degrees, 50 degrees, or 60 degrees, etc. Of course, in other embodiments, β may be less than 0 degrees, or β may be greater than 60 degrees, which is not limited in this application.

[0185] To reduce the noise generated by airflow passing through the connection between the first surface 341 and the tongue 40, as shown in Figure 24 , in some configurations, the connection between the first surface 341 and the tongue surface 32 is formed into a smooth transition. This smooth transition creates less resistance to airflow, allowing airflow to flow more smoothly and reducing noise caused by friction between the first surface 341 and the tongue surface 32. Of course, in other configurations, the connection between the first surface 341 and the tongue surface 32 can be formed into a stepped transition, which is not a limitation of this application.

[0186] To reduce the noise generated by airflow passing through the junction between the first surface 341 and the second surface 343, as shown in Figure 24 , in some structural forms, the junction between the first surface 341 and the second surface 343 forms a smooth transition. This smooth transition creates less resistance to airflow, allowing the airflow to flow more smoothly and reducing noise caused by friction between the first surface 341 and the second surface 343. Of course, in other structural forms, the junction between the first surface 341 and the second surface 343 may form a stepped transition, which is not a limitation of this application.

[0187] Continuing with FIG. 24 , in some structural forms, the connection between the first surface 341 and the volute tongue surface 32 may also be rounded, and the connection between the first surface 341 and the second surface 343 may also be rounded. This can reduce the resistance to airflow at the two connections, allowing the airflow to flow more smoothly and reducing noise caused by friction between the airflow and the two connections.

[0188] Referring to Figures 23 and 24 , in some structural configurations, the distance between the first surface 341 and the outer circumference of the fan 91 in the radial direction of the fan 91 is greater than or equal to 3.5 mm and less than or equal to 7.5 mm. This reduces the noise generated by the shoulder 34 and the fan 91 while also reducing the noise generated by the fan 91 itself during operation. If the distance between the first surface 341 and the outer circumference of the fan 91 is less than 3.5 mm, the first surface 341 will be too close to the fan 91, resulting in excessive interference between the fan 91 and the first surface 341, which in turn increases noise. Furthermore, when the first surface 341 is too close to the fan 91, the possibility of collision between the first surface 341 and the fan 91 increases, both during transportation and during operation. If the distance between the first surface 341 and the outer peripheral surface of the fan 91 is greater than 7.5 mm, the distance between the first surface 341 and the fan 91 will be too large, resulting in excessive leakage of the airflow sent by the fan 91 to the second shell 30. Based on this, it is usually necessary to increase the rotation speed of the fan 91 to maintain the preset air supply volume. Therefore, when the rotation speed of the fan 91 increases, the noise generated by the fan 91 during operation will also increase. For example, the distance between the first surface 341 and the outer peripheral surface of the fan 91 can be 3.5 mm, 4.5 mm, 5.5 mm, 6.5 mm or 7.5 mm, etc. In other structural forms, the distance between the first surface 341 and the outer peripheral surface of the fan 91 can also be less than 3.5 mm, or can be greater than 7.5 mm, and this application does not impose any restrictions on this.

[0189] Referring to Figures 23 and 24 , in the radial direction of the fan 91, the distance between the second surface 343 and the outer circumference of the fan 91 must be greater than or equal to 7.5 mm. This prevents the second surface 343 from being positioned too close to the fan 91, thereby preventing excessive static and dynamic interference between the fan 91 and the second surface 343, and effectively reducing noise. If the distance between the second surface 343 and the outer circumference of the fan 91 is less than 7.5 mm, the second surface 343 will be positioned too close to the fan 91, resulting in excessive static and dynamic interference between the fan 91 and the second surface 343, which can lead to increased noise.

[0190] Referring to FIG. 27 , in some embodiments, two shoulders 34 are provided, one at each of opposite ends of the air inlet surface 31 along the axial direction of the fan 91. This configuration improves the stability of the eccentric vortex and controls its position, given that the eccentric vortices on both sides of the fan 91 along its axial direction are unstable and their positions are unstable.

[0191] Please refer to Figures 27 and 28. Furthermore, in the axial direction of the fan 91, the width H1 of each shoulder 34 should be greater than 10 mm and less than 60 mm. In this way, the shoulder 34 can improve the stability and position control of the eccentric vortices located on both sides of the fan 91 along its axial direction while avoiding interference with the eccentric vortices located in the middle of the fan 91 along its axial direction. If the width H1 of each shoulder 34 is less than or equal to 10 mm, the stabilization and position control effect on the eccentric vortices located on both sides of the fan 91 along its axial direction is weak. If the width H1 of each shoulder 34 is greater than or equal to 60 mm, the shoulder 34 will interfere with the eccentric vortex located in the middle of the fan 91 along its axial direction. For example, the width H1 of each shoulder 34 can be 15 mm, 20 mm, 25 mm, 30 mm, 40 mm, 45 mm, 50 mm or 55 mm, etc. Of course, in other embodiments, the width H1 of each shoulder 34 may be less than or equal to 10 mm, or may be greater than or equal to 60 mm, and this application does not impose any limitation on this.

[0192] Please refer to Figure 27. Furthermore, in the axial direction of the fan 91, the ratio between the width H1 of each shoulder 34 and the width H2 of the air inlet surface 31 is less than or equal to one-third. In this way, the shoulder 34 can improve the stability and position control of the eccentric vortices located on both sides of the fan 91 along its axial direction, while avoiding interference with the eccentric vortex located in the middle of the fan 91 along its axial direction. If the ratio between the width H1 of each shoulder 34 and the width H2 of the air inlet surface 31 is greater than one-third, the shoulder 34 will interfere with the eccentric vortex located in the middle of the fan 91 along its axial direction. For example, the ratio between the width H1 of each shoulder 34 and the width H2 of the air inlet surface 31 can be one-third, one-quarter, one-fifth, etc. Of course, in other embodiments, the ratio between the width H1 of each shoulder 34 and the width H2 of the air inlet surface 31 can also be greater than one-third, and this application is not limited to this.

[0193] Referring to Figure 29 , in some structural forms, the connection between the first surface 341 and the air inlet surface 31 is a smooth transition, and the connection between the second surface 343 and the air inlet surface 31 is a smooth transition. This allows the airflow to flow through the connection between the first surface 341 and the air inlet surface 31 and then through the connection between the second surface 343 and the air inlet surface 31. The smooth transition creates less resistance to the airflow at the connection, allowing the airflow to flow more smoothly and reducing noise caused by friction between the airflow and the connection.

[0194] Please refer to Figure 30. Optionally, the connection between the first surface 341 and the air inlet surface 31 can also be a stepped transition, and the connection between the second surface 343 and the air inlet surface 31 can be a stepped transition. Compared with the connection with multiple bumps and depressions, this can also allow the airflow to flow more smoothly and reduce the noise generated by the airflow. This application does not impose any restrictions on this.

[0195] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of this application, it should be understood that if the terms "up", "down", "left", "right", etc. indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the drawings. This is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only set as illustrative illustrations and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0196] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. An indoor unit, wherein, It includes an air duct assembly and a wind wheel. The air duct assembly defines a fan chamber, and the wind wheel is accommodated in the fan chamber; The air duct assembly includes a volute tongue. The volute tongue includes a first volute tongue part and a second volute tongue part connected to each other. Wherein, in the air supply direction of the wind wheel, the second volute tongue part is arranged closer to the wind wheel than the first volute tongue part.

2. The indoor unit according to claim 1, wherein, The number of the second volute tongue parts is two, and the two second volute tongue parts are connected to opposite ends of the first volute tongue part.

3. The indoor unit according to claim 2, wherein, In the air supply direction of the wind wheel, the distances from each of the second volute tongue parts to the wind wheel are equal or unequal.

4. The indoor unit according to claim 1, wherein, The number of the first volute tongue parts is two, and the two first volute tongue parts are connected to opposite ends of the second volute tongue part.

5. The indoor unit according to claim 1, wherein, In the air supply direction of the wind wheel, the distances from each of the first volute tongue parts to the wind wheel are equal or unequal.

6. The indoor unit according to any one of claims 1 to 5, wherein, A plurality of first guide ribs arranged at intervals protrude from the first volute tongue part, and a first guide groove is defined in cooperation between two adjacent first guide ribs and the first volute tongue part; A plurality of second guide ribs arranged at intervals protrude from each of the second volute tongue parts, and a second guide groove is defined between two adjacent second guide ribs and the second volute tongue part; Wherein, in the air supply direction of the wind wheel, the second guide groove is arranged closer to the wind wheel than the first guide groove.

7. The indoor unit according to any one of claims 1 to 5, wherein, The connection part between the first volute tongue part and the second volute tongue part is arranged with a smooth transition; or, The connection part between the first volute tongue part and the second volute tongue part is arranged with a stepped transition.

8. The indoor unit according to any one of claims 1 to 5, wherein, The first volute tongue part and the second volute tongue part are of an integral structure.

9. The indoor unit according to any one of claims 1 to 8, wherein, It further includes a heat exchanger. The air duct assembly includes a first housing and a second housing. The second housing includes a diffuser chamber bottom shell, a water receiving tray and the volute tongue. Opposite sides of the diffuser chamber bottom shell are respectively connected to the volute tongue and the water receiving tray; The first housing defines the fan chamber and cooperates with the first volute tongue part, the second volute tongue part and the diffuser chamber bottom shell to define a diffuser chamber. The water receiving tray and the first housing cooperate to define a heat exchange chamber. The heat exchanger is accommodated in the heat exchange chamber, and the fan chamber, the diffuser chamber and the heat exchange chamber are communicated in sequence; Wherein, at least part of the diffuser chamber bottom shell and the water receiving tray are of an integral structure.

10. The indoor unit according to claim 1, wherein, The volute tongue has a windward surface, a wind guiding surface and a transition surface. The windward surface faces the wind wheel. The wind guiding surface is arranged at an angle with the windward surface and is configured to guide the airflow flowing out of the wind wheel. The transition surface connects the windward surface and the wind guiding surface; Wherein, the transition surface has a sinking area, and the sinking area is recessed towards the direction close to the wind guiding surface.

11. The indoor unit according to claim 10, wherein, Compared with the boundary line between the sinking area and the windward surface, the boundary line between the sinking area and the wind guiding surface is arranged farther from the wind wheel.

12. The indoor unit according to claim 10, wherein, The sinking area is an arc surface arched towards the direction close to the wind guiding surface.

13. The indoor unit according to claim 10, wherein, The transition surface is further provided with a bulging area, and the bulging area is arched towards the direction away from the wind guiding surface and is smoothly and transitionally connected with the sinking area.

14. The indoor unit according to claim 13, wherein, The volute tongue extends along the axial direction of the impeller. The sinking area is arranged in the middle of the volute tongue and extends towards both ends of the volute tongue. The arching area is arranged at both ends of the sinking area along the extending direction of the volute tongue.

15. The indoor unit according to claim 14, wherein, The volute tongue has a width direction perpendicular to its own extending direction. The width of the sinking area along the width direction gradually decreases from the middle of the volute tongue towards both ends of the volute tongue.

16. The indoor unit according to claim 14, wherein, In the direction from the middle of the volute tongue to both ends of the volute tongue, the distance between the sinking area and the impeller gradually decreases.

17. The indoor unit according to claim 14, wherein, The sinking area is symmetrically arranged with respect to the midline of the volute tongue perpendicular to its own extending direction.

18. The indoor unit according to any one of claims 10 to 17, wherein, The volute tongue further includes a plurality of flow guiding ribs. The plurality of flow guiding ribs are at least connected to the transition surface and are arranged at intervals along the axial direction of the impeller. When projected along the axial direction of the impeller, the flow guiding rib has a flow guiding rib profile line, and the flow guiding rib profile line is parallel to the surface of the sinking area.

19. The indoor unit according to claim 1, wherein, It further includes a blower. The blower is a cross-flow blower and has the impeller. The air duct assembly includes a first housing and a second housing. The first housing and the second housing cooperate to define the blower chamber and a diffuser chamber communicated with the blower chamber. The blower is received in the blower chamber. The second housing includes an air inlet surface, a volute tongue surface, and a diffuser surface connected in sequence. The air inlet surface is configured as a part of the wall of the blower chamber, and the diffuser surface is configured as at least a part of the bottom wall of the diffuser chamber. A shoulder is arranged at the end position of the air inlet surface along the axial direction of the blower. The shoulder connects the volute tongue surface. Among them, the shoulder protrudes towards the blower direction compared with the air inlet surface.

20. The indoor unit according to claim 19, wherein, The side surface of the shoulder facing the blower includes a first surface and a second surface arranged at an angle. The first surface is connected between the volute tongue surface and the second surface, and the second surface extends along the extending direction of the air inlet surface. Among them, the extending length of the first surface is less than the extending length of the second surface.

21. The indoor unit according to claim 20, wherein, In the longitudinal section of the indoor unit along the air flow direction, define the center of the blower as O, the connection point of the volute tongue surface and the diffuser surface as A, the connection point of the volute tongue surface and the air inlet surface as B, and the connection point of the first surface and the second surface as C. The included angle between the line passing through O and A and the line passing through O and B is α, and the included angle between the line passing through O and A and the line passing through O and C is β. Among them, the condition is satisfied that α minus β is greater than or equal to 5 degrees and less than or equal to 30 degrees.

22. The indoor unit according to claim 20, wherein, The first surface extends vertically downward in the height direction of the indoor unit, and the included angle β with the second surface is greater than 0 degree and less than 60 degrees.

23. The indoor unit according to claim 20, wherein, The connection part between the first surface and the volute tongue surface is in a smooth transition. And / or, the connection part between the first surface and the second surface is in a smooth transition.

24. The indoor unit according to claim 20, wherein, The connection part between the first surface and the air inlet surface is in a smooth transition, and the connection part between the second surface and the air inlet surface is in a smooth transition.

25. The indoor unit according to claim 20, wherein, The connection part between the first surface and the air inlet surface is in a stepped transition, and the connection part between the second surface and the air inlet surface is in a stepped transition.

26. The indoor unit according to claim 20, wherein, In the radial direction of the blower, the distance between the first surface and the outer peripheral surface of the blower is greater than or equal to 3.5 mm and less than or equal to 7.5 mm.

27. The indoor unit according to claim 20, wherein, In the radial direction of the blower, the distance between the second surface and the outer peripheral surface of the blower is greater than or equal to 7.5 mm.

28. The indoor unit according to any one of claims 19 to 27, wherein, The shoulder portion includes two parts which are respectively arranged at opposite ends of the air inlet surface along the axial direction of the blower.

29. The indoor unit according to claim 28, wherein, In the axial direction of the blower, the width of each shoulder portion is greater than 10 mm and less than 60 mm.

30. The indoor unit according to claim 28, wherein, In the axial direction of the blower, the ratio between the width of each shoulder portion and the width of the air inlet surface is less than or equal to one third.

31. A heating, ventilation, and air conditioning (HVAC) device, wherein, Comprising an outdoor unit and an indoor unit according to any one of claims 1 to 30, wherein the indoor unit and the outdoor unit form a refrigerant cycle.

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