Indoor unit and heating and ventilation system

Abstract

The present application discloses an indoor unit and a heating and ventilation system. The indoor unit comprises a housing, a blower wheel, and a volute tongue structure; an air outlet and an air inlet are spaced apart from each other in the housing, and an air duct communicated with the air inlet and the air outlet is formed; the blower wheel is arranged in the air duct; and the volute tongue structure is arranged between the blower wheel and the air outlet. The volute tongue structure is provided with an air guide surface and a windward side, and the windward side comprises a first volute tongue section, a second volute tongue section, and a transition section. The second volute tongue section and the first volute tongue section are spaced apart from each other and are arranged in an arc shape. The transition section connects the first volute tongue section to the second volute tongue section. When projection is performed in the extending direction of the volute tongue structure, the contour line of the transition section is lower than the tangent line of the first volute tongue section and the second volute tongue section, or the contour line of the transition section is flush with the tangent line of the first volute tongue section and the second volute tongue section.

Description

Indoor unit and heating and ventilation system

[0001] The present application claims priority to the Chinese patent application No. 2024105282328, filed on April 29, 2024, and entitled "Indoor unit and heating and ventilation system", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of heating and ventilation technology, in particular to an indoor unit and a heating and ventilation system. BACKGROUND

[0003] The heating and ventilation system comprises an air conditioner indoor unit for adjusting an indoor environment, and the air conditioner indoor unit can adopt the form of an indoor unit, i.e., being hung on a ceiling.

[0004] A volute tongue is usually arranged in an air duct of the air conditioner indoor unit to prevent part of the gas from circulating in the volute. However, the volute tongue in the related art has a relatively poor aerodynamic efficiency and generates a large noise, resulting in a poor user experience. SUMMARY

[0005] The embodiments of the present application provide an indoor unit and a heating and ventilation system, which can improve the aerodynamic efficiency and reduce the noise.

[0006] In a first aspect, the embodiments of the present application provide an indoor unit, comprising a shell, a fan wheel, and a volute tongue structure. The shell is provided with an air outlet and an air inlet at the bottom thereof and is formed with an air duct communicating the air inlet and the air outlet. The fan wheel is arranged in the air duct. The volute tongue structure is arranged between the fan wheel and the air outlet and extends along the axial direction of the fan wheel. The volute tongue structure has a guide surface facing away from the fan wheel and an air-impingement surface facing the fan wheel. The air-impingement surface comprises:

[0007] a first volute tongue segment arranged in an arc-shaped profile line facing the fan wheel;

[0008] a second volute tongue segment arranged in an arc-shaped profile line facing the fan wheel and spaced apart from the first volute tongue segment; and

[0009] a transition segment connecting the first volute tongue segment and the second volute tongue segment. The airflow flowing through the air-impingement surface can pass through the first volute tongue segment, the transition segment, and the second volute tongue segment in sequence.

[0010] In the projection along the extension direction of the volute tongue structure, the profile line of the transition segment is lower than the tangent line of the first volute tongue segment and the second volute tongue segment, or the profile line of the transition segment is flush with the tangent line of the first volute tongue segment and the second volute tongue segment.

[0011] In an embodiment, the profile of the transition section is lower than the tangent of the first volute tongue section and the second volute tongue section in the projection along the extension direction of the volute tongue structure, and the transition section is an arc section that is arched away from the impeller.

[0012] Based on the above embodiments, it is beneficial to make the return air more smooth

[0013] In an embodiment, the distance between the windward surface and the outer edge of the impeller is constant, or gradually decreases, or first increases and then decreases, in the direction from the first volute tongue section to the second volute tongue section.

[0014] Based on the above embodiments, the stability of the air flow is maintained, and the air volume and air flow efficiency are ensured.

[0015] In an embodiment, the first volute tongue section and the outer edge of the impeller have a first gap h1, and the first gap satisfies the relationship: 6mm≤h1≤12mm; and / or,

[0016] The second volute tongue section and the outer edge of the impeller have a second gap h2, and the second gap satisfies the relationship: 4mm≤h2≤10mm.

[0017] In an embodiment, the first gap h1 is greater than the second gap h2.

[0018] Based on the above embodiments, the return air efficiency is ensured to reduce noise

[0019] In an embodiment, the first volute tongue section, the transition section and the second volute tongue section are smoothly connected.

[0020] Based on the above embodiments, the resistance to air flow is reduced, the friction loss is reduced, the smoothness of the return air flow is improved, and the return air efficiency is improved.

[0021] In an embodiment, in the height direction of the indoor unit in the installed state, the first volute tongue section is higher than the second volute tongue section.

[0022] Based on the above embodiments, the return air flow between the windward surface and the impeller can be ensured.

[0023] In an embodiment, the curvature of the first volute tongue section is greater than the curvature of the second volute tongue section.

[0024] Based on the above embodiments, the air flow can be better separated when facing the air flow, and the return air volume is ensured.

[0025] In an embodiment, in the cross section of the indoor unit perpendicular to the axial direction of the impeller, the center of the impeller is defined as O, the starting point of the first volute tongue section is N, and the end point of the second volute tongue section is L.

[0026] wherein ∠NOL is an included angle of the volute tongue structure, and satisfies the relationship: 15°≤∠NOL≤30°.

[0027] Based on the above embodiments, the pneumatic efficiency and the effectiveness of airflow guiding are ensured, and the noise level is controlled.

[0028] In an embodiment, on a cross section of the indoor unit perpendicular to an axial direction of the impeller, a starting point of the second volute tongue section is defined as M, and ∠MOL is an included angle of the second volute tongue section, and satisfies the relationship: 2°≤∠MOL≤10°.

[0029] Based on the above embodiments, the smoothness and efficiency of return air are ensured.

[0030] In an embodiment, the volute tongue structure further comprises a leading edge air guide section, and the leading edge air guide section connects the first volute tongue section and the air guide surface.

[0031] Based on the above embodiments, the airflow is buffered and guided, and the smoothness of airflow flow is improved.

[0032] In an embodiment, in a projection along an extension direction of the volute tongue structure, a profile line of the air guide surface is arranged in a straight line, a profile line of the leading edge air guide section is arranged in an arc shape, and an end point of the profile line of the leading edge air guide section overlaps with a starting point of the profile line of the air guide surface.

[0033] Based on the above embodiments, the airflow can be directly guided to the air guide surface by the leading edge air guide section, and the continuity of the airflow is good.

[0034] In an embodiment, the profile line of the air guide surface is tangent to the arc-shaped profile line of the leading edge air guide section.

[0035] Based on the above embodiments, the along-the-way loss of the airflow is reduced, and the air outlet efficiency is improved

[0036] In an embodiment, the leading edge air guide section has an arc radius R1, and satisfies the relationship: 5mm≤R1≤9mm.

[0037] Based on the above embodiments, the return air efficiency and the smoothness of the airflow are ensured.

[0038] In an embodiment, the volute tongue structure further comprises a plurality of flow guide ribs, and along the extension direction of the volute tongue structure, the plurality of flow guide ribs are protruded on at least the windward surface at intervals, and the flow guide ribs are connected to at least the first volute tongue section and the transition section.

[0039] Based on the above embodiments, the interference area of the airflow and the surface of the flow guide rib is small, thereby reducing the noise.

[0040] In an embodiment, a front edge air guide section is further included, which connects the first volute tongue section and the air guide surface, each of the guide vanes is configured to include a windward vane section and an air guide vane section, the air guide vane section is arranged at the front edge air guide section, and the windward vane section is arranged at least at the first volute tongue section and the transition section.

[0041] Based on the above embodiment, the interference area of the air flow blowing to the front edge air guide section is reduced, thereby reducing the noise.

[0042] In an embodiment, the windward vane section has an arc-shaped profile line, the profile line of the windward vane section is arranged correspondingly to the profile line of the first volute tongue section and the transition section, and the profile line of the windward vane section ends at the end point of the profile line of the transition section.

[0043] Based on the above embodiment, the continuity of the air flow guidance is ensured, and the production cost of the volute tongue structure is reduced.

[0044] In an embodiment, the air guide vane section has an arc-shaped profile line, the profile line of the air guide vane section is arranged correspondingly to the profile line of the front edge air guide section, and the arc-shaped profile line of the air guide vane section ends at the end point of the profile line of the front edge air guide section.

[0045] Based on the above embodiment, the continuity of the air flow guidance is ensured, and the production cost of the volute tongue structure is reduced.

[0046] In an embodiment, the distance between the top surface of the windward vane section and the windward surface gradually decreases from the first volute tongue section to the end point of the transition section; and / or,

[0047] the distance between the top surface of the air guide vane section and the surface of the front edge air guide section gradually decreases from the first volute tongue section to the air guide surface.

[0048] Based on the above embodiment, a better air flow guidance effect is achieved and the return air volume is ensured.

[0049] In an embodiment, along the extension direction of the volute tongue structure, the distance between two adjacent guide vanes satisfies the relationship: 2mm≤d1≤4mm; and / or,

[0050] the width of the guide vane along the extension direction of the volute tongue structure satisfies the relationship: 1mm≤d2≤3mm; and / or,

[0051] the distance between the top surface of the guide vane and the surface of the volute tongue structure satisfies the relationship: 2mm≤d3≤4mm.

[0052] Based on the above embodiment, the air flow stability is improved, and the noise can be effectively reduced.

[0053] In an embodiment, a rear edge air guide section is further included, which is connected to the second volute tongue section and extends in a direction away from the second volute tongue section;

[0054] In the embodiment, a contour line of the rear edge air guide section is linear in a projection along an extension direction of the volute tongue structure.

[0055] Based on the above embodiment, air supplement is facilitated and return air efficiency is improved.

[0056] In an embodiment, the rear edge air guide section is tangent to the second volute tongue section, so that air flow is relatively smooth from the second volute tongue section to the rear edge air guide section.

[0057] In an embodiment, the indoor unit further includes a heat exchanger, and the shell includes:

[0058] The shell has an open bottom;

[0059] The bottom plate and the water pan are arranged in the shell, and the bottom plate is above the water pan. The bottom plate, the water pan, and the shell cooperatively define the air duct. The heat exchanger is arranged in the air duct and is upstream of the fan wheel. The volute tongue structure is connected to the water pan.

[0060] The panel covers the opening and is provided with the air inlet and the air outlet.

[0061] Based on the above embodiment, the shell is relatively flat and occupies less space.

[0062] In an embodiment, the volute tongue structure includes a first sub-member and a second sub-member connected to each other. The first sub-member is connected to the water pan. The second sub-member is detachably connected to the water pan and / or the first sub-member.

[0063] The air guide surface is arranged on a side of the first sub-member away from the fan wheel. The windward surface is arranged on a side of the second sub-member facing the fan wheel, facilitating disassembly and maintenance.

[0064] In an embodiment, the first sub-member and the second sub-member enclose a closed hollow cavity, so as to reduce weight and facilitate manufacturing of the volute tongue structure.

[0065] In a second aspect, an embodiment of the present application provides a heating and ventilation system, including:

[0066] An outdoor unit; and

[0067] The indoor unit according to any one of the above embodiments, the indoor unit and the outdoor unit having circulating refrigerant.

[0068] Based on the above embodiment, by setting the first volute tongue section, the transition section and the second volute tongue section, the first volute tongue section and the second volute tongue section are both arranged in an arc-shaped contour line, the transition section connects the first volute tongue section and the second volute tongue section, and the tangent line of the transition section is not higher than that of the first volute tongue section and the second volute tongue section, so that the airflow of the return air flowing along the windward surface is buffered, the return air is smoother and more stable, and the effect of stabilizing the eccentric vortex is achieved, thereby improving the aerodynamic efficiency. Since the stability of the return air flow is improved, the effect of reducing noise can also be achieved, and the user experience is improved. BRIEF DESCRIPTION OF DRAWINGS

[0069] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained according to the structures shown in the drawings without creative labor for those skilled in the art.

[0070] Fig. 1 is a structural schematic diagram of an embodiment of the indoor unit of the present application;

[0071] Fig. 2 is a sectional schematic diagram of the indoor unit A-A in Fig. 1;

[0072] Fig. 3 is a sectional structural schematic diagram of another embodiment of the indoor unit of the present application;

[0073] Fig. 4 is a structural schematic diagram of the fan wheel and the volute tongue structure in Fig. 3;

[0074] Fig. 5 is a structural schematic diagram of the fan wheel and the volute tongue structure in another embodiment of the present application;

[0075] Fig. 6 is a sectional structural schematic diagram of still another embodiment of the indoor unit of the present application;

[0076] Fig. 7 is an enlarged structural schematic diagram of C in Fig. 6;

[0077] Fig. 8 is an enlarged structural schematic diagram of B in Fig. 2;

[0078] Fig. 9 is a top view structural schematic diagram of an embodiment of the volute tongue structure of the present application;

[0079] Fig. 10 is an assembly schematic diagram of the volute tongue structure of the present application.

[0080] Brief Description of Drawings: 100, indoor unit; 10, shell; 11, casing; 12, panel; 121, air outlet; 122, air inlet; 13, bottom plate; 14, water pan; 15, air duct; 151, air inlet part; 152, air outlet part; 30, volute tongue structure; 301, first sub-member; 303, second sub-member; 305, closed hollow cavity; 31, air guide surface; 32, windward surface; 321, first volute tongue section; 323, transition section; 325, second volute tongue section; 33, leading edge air guide section; 34, trailing edge air guide section; 35, flow guide rib; 351, air guide rib section; 353, windward rib section; 50, fan wheel; 70, heat exchanger.

[0081] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0082] In order to make the purpose, technical solutions and advantages of the present application more clear, the following will further describe the embodiments of the present application in connection with the accompanying drawings.

[0083] The following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all the embodiments consistent with the present application. Instead, they are merely examples of apparatuses and methods consistent with some aspects of the present application as detailed in the appended claims.

[0084] In the description of the present application, it is to be understood that the terms "first", "second" and the like are used only for descriptive purposes and are not to be construed as indicating or implying relative importance. For those skilled in the art, the specific meaning of the above terms in the present application can be understood in specific cases. In addition, in the description of the present application, unless otherwise specified, "multiple" means two or more. "And / or", the association between the associated objects, means that there can be three relationships, for example, A and / or B, which can represent the existence of A alone, the existence of A and B, and the existence of B alone. The character " / " generally represents a "or" relationship between the associated objects before and after.

[0085] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0086] The embodiment of the present application proposes a heating and ventilation system. The heating and ventilation system is one of commonly used air conditioning devices, which is used to adjust the indoor ambient temperature (some of the heating and ventilation systems also have the functions of adjusting humidity, purification, etc.). In the embodiment of the present application, the heating and ventilation system includes but is not limited to air conditioners, multi-split air conditioners, heat pumps and other devices, and can be applied in large-scale places such as shopping malls and office buildings. Exemplarily, the heating and ventilation system can include an indoor unit 100, an outdoor unit and a connecting pipe. The indoor unit 100 is connected with the outdoor unit through the connecting pipe, so that the indoor unit 100 and the outdoor unit form a circulating flow path. In some actual use scenarios, the indoor unit 100 of the present application can be installed indoors, and the outdoor unit is responsible for refrigeration or heating and transports refrigerant through the connecting pipe. The refrigerant exchanges heat with indoor air and outdoor air respectively, and the indoor unit 100 is responsible for delivering cold air or hot air to the indoor to achieve the effect of cooling or heating.

[0087] Another aspect of the embodiment of the present application proposes an indoor unit 100. The indoor unit 100 can include but is not limited to a ceiling type air conditioner, a ducted air conditioner, a wall-mounted air conditioner indoor unit 100 and a floor-standing air conditioner indoor unit 100, etc. The installation mode of the ceiling type air conditioner can hide it inside the ceiling of the building, which does not occupy the available space indoors. This is particularly important for those environments with limited space (such as offices, shops and residences), and can effectively utilize the space.

[0088] Please refer to FIG. 1 and FIG. 2. In some embodiments of the present application, the indoor unit 100 includes a shell 10, a heat exchanger 70, a fan wheel 50 and a volute tongue structure 30.

[0089] In the installed state, the indoor unit has an up-down direction ZZ, a front-rear direction YY and a left-right direction XX. The up-down direction ZZ, the front-rear direction YY and the left-right direction XX are arranged at an included angle with each other. Further, the included angle can be 90°.

[0090] The outer contour of the shell 10 can be a generally rectangular parallelepiped extending in the left-right direction. The shell 10 forms an air duct 15 and an air inlet 122 and an air outlet 121.

[0091] The air duct 15 includes an air inlet portion 151 between the heat exchanger 70 and the fan wheel 50, and an air outlet portion 152 between the fan wheel 50 and the air outlet 121. In this way, when the heating and ventilation system is working, the fan wheel 50 rotates, the airflow enters the air duct 15 through the air inlet 122, exchanges heat with the heat exchanger 70, and then flows to the air inlet portion 151. After that, the heat-exchanged airflow flows to the air outlet portion 152 through the fan wheel 30, and is blown out to the indoor through the air outlet 121, so that the indoor ambient temperature can be adjusted.

[0092] The wind wheel can extract the gas in the air inlet part 151 and work on the gas to make the gas flow to the air outlet part 152 at a faster flow rate, thereby providing power for the gas circulation of the air duct 15. The wind wheel 50 can be a cross-flow wind wheel 50, a centrifugal wind wheel 50, or an axial flow wind wheel 50, etc. When the wind wheel 50 is configured as a cross-flow wind wheel 50, the cross-flow wind wheel 50 has the advantages of small radial size, low rotation speed, low noise, uniform air outlet, etc. The axial length of the cross-flow wind wheel 50 can be arbitrarily lengthened without affecting the gas flow state, etc. Compared with the centrifugal wind wheel 50 or the axial flow wind wheel 50, the cross-flow wind wheel 50 has a lower cost.

[0093] The heat exchanger 70 and the wind wheel 50 are arranged in the air duct 15 in the air flow direction and are located upstream of the wind wheel 50. Optionally, the heat exchanger 70 can have various shapes such as a straight line, a V shape, an arc shape, or a wave shape. The heat exchanger 70 is used to exchange heat with the gas passing through the heat exchanger 70, thereby playing a role of refrigerating or heating the gas. For example, a plurality of refrigerant pipes are arranged in the heat exchanger 70 (for example, the circular shape in the heat exchanger 70 in FIGS. 1 and 2 represents a refrigerant pipe), and the gas exchanges heat with the refrigerant in the pipe when passing through the heat exchanger 70, thereby changing the temperature of the gas. Specifically, when refrigerating, the gas exchanges heat with the refrigerant of the heat exchanger 70 to form low-temperature air; and when heating, the gas exchanges heat with the refrigerant of the heat exchanger 70 to form heated air.

[0094] The volute tongue structure 30 is arranged between the wind wheel 50 and the air outlet 121, and is used to guide part of the air flow blown by the wind wheel 50 to the air outlet 121, and part of the air flow flows back to the air inlet part 151 through the gap between the volute tongue structure 30 and the wind wheel 50. The air flow is blown out of the air outlet 121 to the indoor environment, thereby achieving the adjustment of the indoor environment temperature.

[0095] In the ceiling machine shown in FIGS. 1 and 2, the air outlet 121 and the air inlet 122 are arranged on the bottom surface of the shell 10, and when the indoor unit 100 is installed indoors, the bottom surface is exposed to the ceiling and arranged towards the indoor environment. Since the air outlet 121 and the air inlet 122 are both located on the bottom surface, the indoor unit 100 only has one side to inhale and discharge the air flow, which is more conducive to the flat design of the indoor unit 100 to adapt to the environment with smaller installation space. However, due to the large corner of the air flow path, the air flow loss along the path is large, and it is of great significance to ensure good aerodynamic efficiency for the air volume and other parameters of the air outlet of the ceiling machine. The design of the volute tongue structure 30 in the related art greatly affects the aerodynamic efficiency and has a large noise, which greatly affects the user experience.

[0096] Please refer to FIG. 2 and FIG. 3, in the volute tongue structure 30 of the embodiment of the present application, the volute tongue structure 30 extends along the axial direction of the wind wheel 50, in the illustrated embodiment, the axial direction of the volute tongue structure 30 and the axial direction of the wind wheel 50 both extend along the left-right direction XX, and the length of the volute tongue structure 30 in the left-right direction XX is greater than or equal to the length of the wind wheel 50 in the left-right direction XX, so as to ensure that the volute tongue structure 30 can guide the airflow blown by the wind wheel 50 comprehensively.

[0097] The volute tongue structure 30 has a wind guide surface 31 and a windward surface 32. The wind guide surface 31 is arranged substantially away from the wind wheel 50, and the windward surface 32 is arranged substantially toward the wind wheel 50. In the airflow blown by the wind wheel 50 toward the volute tongue structure 30, part of the airflow flows to the air outlet 121 under the guidance of the wind guide surface 31, and another part of the airflow flows through the gap between the windward surface 32 and the wind wheel 50, and then flows back to the wind wheel 50 again. During the gas flow, the gas forms an airflow vortex (eccentric vortex) with a center near the volute tongue structure 30. Unreasonable design of the profile of the volute tongue structure 30 can easily cause improper size and position of the eccentric vortex in the cross-flow wind wheel 50, resulting in poor backflow of another part of the airflow, affecting the aerodynamic efficiency and causing relatively large noise.

[0098] Please continue to refer to FIG. 3 to FIG. 5, in some embodiments, the windward surface 32 includes a first volute tongue section 321, a second volute tongue section 325, and a transition section 323. The second volute tongue section 325 is arranged in the front-rear direction YY spaced apart from the first volute tongue section 321, and the transition section 323 connects the first volute tongue section 321 and the second volute tongue section 325, so that the airflow flowing through the windward surface 32 can pass through the first volute tongue section 321, the transition section 323 and the second volute tongue section 325 in turn.

[0099] One end of the first volute tongue section 321 is connected to the wind guide surface 31, and the first volute tongue section 321 is arranged in an arc shape toward the wind wheel 50, so as to facilitate the division of the airflow blown nearby into two parts, one part flows to the wind guide surface 31, and the other part flows along the first volute tongue section 321 to the transition section 323 and the second volute tongue section 325.

[0100] The second volute tongue section 325 is arranged in an arc shape toward the wind wheel 50, which can maintain a relatively stable gap size between the windward surface 32 and the wind wheel 50, improve the stability of the airflow, and further guide the airflow, facilitate the backflow, and further improve the backflow efficiency.

[0101] The profile line of the transition section 323 is lower than or flush with the tangent line of the first volute tongue section 321 and the second volute tongue section 325 in the projection along the extension direction of the volute tongue structure 30. In this way, the gap between the transition section 323 and the wind wheel 50 can be smoothly transitioned, and the gap in this part is not suddenly reduced, so that the airflow returning along the windward surface 32 is buffered, the flow rate is slowed down, the airflow resistance is effectively reduced, and the airflow is smoother.

[0102] Unlike the volute tongue structure 30 with an arc line in the related art, in the embodiment of the present application, the first volute tongue section 321, the transition section 323, and the second volute tongue section 325 are provided, the first volute tongue section 321 and the second volute tongue section 325 are both arc-shaped, the transition section 323 connects the first volute tongue section 321 and the second volute tongue section 325, and the tangent line of the transition section 323 is not higher than the tangent line of the first volute tongue section 321 and the second volute tongue section 325. The airflow returning along the windward surface 32 is buffered, the returning airflow is smoother and more stable, and the effect of stabilizing the eccentric vortex is achieved, thereby improving the aerodynamic efficiency. Due to the improved stability of the returning airflow, the effect of reducing noise is also achieved, and the user experience is improved.

[0103] Please refer to FIGS. 4, 6, and 7. In an embodiment, the transition section 323 is an arc section arched away from the wind wheel 50 in the projection along the extension direction of the volute tongue structure 30. In this embodiment, the volute tongue structure 30 extends along the left-right direction XX, and the profile line of the transition section 323 is obtained in the projection along the left-right direction XX. The profile line of the transition section 323 is an arc end arched away from the wind wheel 50. Since the edge of the wind wheel 50 is also arc-shaped, the gap between the transition section 323 and the wind wheel 50 is also generally arc-shaped. In combination with the first volute tongue section 321 and the second volute tongue section 325, the entire windward surface 32 is generally convex-concave-convex. The arc-shaped transition section 323 has small resistance to airflow and good guiding effect, which is conducive to making the airflow return more smoothly and conducive to air supplement on the inlet side of the wind wheel 50.

[0104] Optionally, the distance between the windward face 32 and the outer edge of the wind wheel 50 is constant in the direction from the first volute tongue section 321 to the second volute tongue section 325, so as to keep the stability of the airflow flow, and thus to stabilize the airflow flow rate and the gas flow rate, so as to stabilize the air supplement effect on the side of the wind wheel 50 close to the heat exchanger 70. Alternatively, in another embodiment, the distance between the windward face 32 and the outer edge of the wind wheel 50 gradually decreases in the direction from the first volute tongue section 321 to the second volute tongue section 325. Obviously, the airflow flow rate is large near the first volute tongue section 321, and the airflow is gradually buffered and the wind force is gradually attenuated during the flow along the transition section 323. The distance between the windward face 32 and the outer edge of the wind wheel 50 is gradually reduced, so that the gap transition is uniform, the airflow is buffered, the airflow flow rate is maintained, and the air volume is ensured. Of course, in other embodiments, the distance between the windward face 32 and the outer edge of the wind wheel 50 can first increase and then decrease, for example, the transition section 323 arranged in an arc shape has a portion with a large curvature, so that the airflow is buffered, the airflow impact is reduced, and the noise is reduced, and then the air volume and the airflow flow efficiency are ensured through the reduced gap.

[0105] Please refer to FIG. 4 and FIG. 7, in some embodiments, in the height direction of the indoor unit 100, that is, in the up-down direction ZZ in the embodiment, the first volute tongue section 321 is higher than the second volute tongue section 325. It can be understood that if the first volute tongue section 321 is not higher than the second volute tongue section 325, that is, the first volute tongue section 321 is lower than the second volute tongue section 325 or substantially flush with the second volute tongue section 325, the first volute tongue section 321 cannot better separate the airflow, and due to the lower first volute tongue section 321, the gap between the first volute tongue section 321 and the wind wheel 50 cannot be maintained, so that the airflow flow rate of the airflow blown by the wind wheel 50 into the gap between the windward face 32 and the wind wheel 50 cannot be ensured, resulting in a decrease in the return air volume and a decrease in the aerodynamic efficiency. Therefore, the embodiment of the present application limits that in the height direction of the indoor unit 100, the first volute tongue section 321 is higher than the second volute tongue section 325, so as to ensure the return air flow rate into the gap between the windward face 32 and the wind wheel 50, and thus to ensure the aerodynamic efficiency and further to stabilize the eccentric vortex.

[0106] As shown in FIG. 7, the first volute tongue segment 321 has a first gap with the outer edge of the wind wheel 50, and the vertical distance between the surface of the first volute tongue segment 321 and the outer edge of the wind wheel 50 is the width h1 of the first gap (i.e., the vertical distance from the inflection point of the arc profile line of the first volute tongue segment 321 to the wind wheel 50). In an embodiment, the first gap h1 satisfies the relationship: 6mm≤h1≤12mm. It can be understood that if the first gap h1>12mm, the gap width between the outer edge of the wind wheel 50 and the first volute tongue segment 321 is too large, which can cause serious air leakage, resulting in air return quantity attenuation and reducing the air return efficiency. When the first gap h1<6mm, the gap between the outer edge of the wind wheel 50 and the first volute tongue segment 321 is too small, the flow rate of the airflow through the gap is too fast, and the airflow impact effect is strong, thereby causing the noise value to be too high, and in severe cases, a howling sound can be generated. Therefore, by comprehensively considering the flow efficiency, air volume and noise of the airflow between the first volute tongue segment 321 and the outer edge of the wind wheel 50, the embodiment of the present application limits 6mm≤h1≤12mm to ensure the air return efficiency and reduce the noise. The first gap h1 can be selected as 7mm, 8mm, 10mm, etc., which is not limited in the embodiment.

[0107] Further, the second volute tongue segment 325 has a second gap with the outer edge of the wind wheel 50, and the vertical distance between the surface of the second volute tongue segment 325 and the outer edge of the wind wheel 50 is the width h2 of the second gap (i.e., the vertical distance from the inflection point of the arc profile line of the second volute tongue segment 325 to the wind wheel 50). In an embodiment, the second gap h2 satisfies the relationship: 4mm≤h2≤10mm. It can be understood that if the second gap h2>10mm, the gap width between the outer edge of the wind wheel 50 and the second volute tongue segment 325 is too large, which can cause poor air supplement effect of the airflow to the wind wheel 50, reducing the air return efficiency. When the second gap h2<4mm, the gap between the outer edge of the wind wheel 50 and the second volute tongue segment 325 is too small, the flow rate of the airflow through the gap is too fast, and the airflow impact effect is strong, thereby causing the noise value to be too high. Therefore, by comprehensively considering, to ensure the air return efficiency and reduce the aerodynamic noise, the embodiment of the present application limits 4mm≤h2≤10mm. The second gap h2 can be selected as 4mm, 6mm, 7mm or 8mm, etc., which is not limited in the embodiment.

[0108] In some optional embodiments, the first gap h1 is greater than the second gap h2, so as to further ensure the air return air volume, reduce the airflow impact, and improve the air supplement effect of the wind wheel 50 on the air inlet side, thereby improving the air return efficiency.

[0109] As shown in FIG. 4, in an embodiment, the curvature of the first volute tongue section 321 is greater than the curvature of the second volute tongue section 325. The greater curvature makes the first volute tongue section 321 have a more obvious bending degree, so as to better separate the airflow when facing the airflow, thereby ensuring the return air flow rate and improving the return air efficiency. The curvature of the second volute tongue section 325 is smaller, the profile is more gentle, the blocking effect on the airflow is smaller, the airflow can be better guided, the airflow can be more stably supplemented, and the noise can be reduced. By making the curvature of the first volute tongue section 321 greater than the curvature of the second volute tongue section 325, the embodiment can ensure the return air flow rate, make the return air more smooth, and appropriately reduce the noise.

[0110] Please continue to refer to FIGS. 3 to 5. In the cross section of the indoor unit 100 perpendicular to the axial direction of the impeller 50, the impeller 50 has a center. It can be understood that the central axis of the rotating shaft of the impeller 50 passes through the center of the impeller 50. From the cross section, the impeller 50 rotates around the center. The first volute tongue section 321 and the second volute tongue section 325 each have a starting point and an ending point. It can be understood that the starting point of the first volute tongue section 321 is located at one end of the first volute tongue section 321 close to the guide surface 31, and the ending point is located at the junction of the first volute tongue section 321 and the transition section 323. The starting point of the second volute tongue section 325 is located at the junction of the second volute tongue section 325 and the transition section 323, and the ending point of the second volute tongue section 325 is located at one end of the second volute tongue section 325 close to the heat exchanger 70.

[0111] The center of the impeller 50 is defined as O, the starting point of the first volute tongue section 321 is N, and the ending point of the second volute tongue section 325 is L, wherein ∠NOL is the envelope angle of the volute tongue structure 30. In an embodiment, the cross section is perpendicular to the left-right direction XX, and the envelope angle of the volute tongue structure 30 satisfies the relationship: 15°≤∠NOL≤30°. The envelope angle of the volute tongue structure 30 reflects the relative relationship between the volute tongue structure 30 and the impeller 50. In combination with FIG. 3, the greater the ∠NOL, the greater the range of the volute tongue structure 30 covering the impeller 50, and the greater the range of action, and vice versa. It can be understood that if ∠NOL>30°, the range of action of the volute tongue structure 30 is too large, the eccentric vortex mainly occurs around the volute tongue structure 30, and the too large volute tongue structure 30 will make the eccentric vortex larger, reduce the flow area, and affect the air output. If ∠NOL<15°, the range of action of the volute tongue structure 30 is too small, which cannot effectively guide the airflow, and noise is easily generated. Therefore, the embodiment limits 15°≤∠NOL≤30° to ensure the aerodynamic efficiency and the effectiveness of airflow guidance, and control the noise level. Alternatively, the size of ∠NOL can be selected as 15°, 20°, 23°, etc., which is not limited in the embodiment.

[0112] Please continue to refer to FIG. 3, in an embodiment, still in the cross section of the indoor unit 100 perpendicular to the axial direction of the impeller 50, the starting point of the second volute tongue section 325 is defined as M, and the included angle MOL is the envelope angle of the second volute tongue section 325, which satisfies the relationship: 2°≤∠MOL≤10°. The envelope angle of the second volute tongue section 325 reflects the relative action relationship between the second volute tongue section 325 and the impeller 50. Understandably, the larger the ∠MOL is, the larger the action range of the second volute tongue section 325 is, and vice versa. Understandably, if ∠MOL>10°, the action range of the second volute tongue section 325 is too large, the airflow flow is unstable, and the return air effect is affected; and if ∠MOL<2°, the action range of the volute tongue structure 30 is too small, and the airflow cannot be effectively guided, affecting the aerodynamic efficiency. Therefore, in order to ensure the smoothness of the return air and the efficiency of the return air, the embodiments of the present application limit 2°≤∠MOL≤10°. Optionally, the size of ∠MOL can be selected as 3°, 5°, 8°, etc., and the embodiments do not limit this.

[0113] In some embodiments of the present application, the first volute tongue section 321, the transition section 323 and the second volute tongue section 325 are smoothly connected to reduce the resistance to airflow, reduce the along-the-way loss, improve the smoothness of the return air flow, and improve the return air efficiency. Among them, the first volute tongue section 321, the transition section 323 and the second volute tongue section 325 can all be arranged as an arc to further buffer the airflow, improve the smoothness of the return air, and further improve the aerodynamic efficiency.

[0114] Please refer to FIG. 4 and FIG. 5, in an embodiment, the volute tongue structure 30 further includes a leading edge air guide section 33, and the leading edge air guide section 33 connects the first volute tongue section 321 and the air guide surface 31. Understandably, the leading edge air guide section 33 is used to transitionally connect the first volute tongue section 321 and the air guide surface 31, and the airflow blown by the impeller 50 is separated by the first volute tongue section 321 and partially flows to the air guide surface 31 through the leading edge air guide section 33. Among them, the leading edge air guide section 33 can be arranged in an arch shape, which can play a role in buffering and guiding the airflow, and improving the smoothness of the airflow flow.

[0115] In an embodiment, the profile line of the leading edge air guide section 33 is arranged in an arc shape along the projection direction of the volute tongue structure 30 (i.e. along the left-right direction XX), which is convenient for guiding the airflow; and the profile line of the air guide surface 31 is arranged in a straight line, so as to maintain the smooth flow of the airflow, promote the static pressure conversion, and improve the air supply distance. In the present embodiment, the end point of the profile line of the leading edge air guide section 33 overlaps with the starting point of the profile line of the air guide surface 31, the airflow can be directly guided to the air guide surface 31 by the leading edge air guide section 33, the airflow has good continuity, and the airflow is relatively smooth.

[0116] Further, the profile line of the air guide surface 31 is tangent to the arc profile line of the leading edge air guide section 33, the airflow transition is smoother, the airflow turbulence is reduced, the along-the-way loss of the airflow is reduced, and the air outlet efficiency is improved.

[0117] Optionally, in combination with FIG. 7, in an embodiment, the arc-shaped front edge air guide section 33 has an arc radius R1 that satisfies the relationship: 5mm≤R1≤9mm. Understandably, if the arc radius R1 of the front edge air guide section 33 is greater than 9mm, the curvature of the front edge air guide section 33 is smaller, the transition of the front edge air guide section 33 to the first volute tongue section 321 and the air guide surface 31 is more uneven, the air flow impact effect is stronger, and the air flow is not smooth, which increases the noise. If the arc radius R1 is less than 5mm, the bending degree of the front edge air guide section 33 is too large, which cannot well assist the first volute tongue section 321 to separate the air flow, and reduces the return air efficiency. Therefore, the embodiment limits the arc radius R1 to satisfy the relationship: 5mm≤R1≤9mm, to ensure the return air efficiency, improve the air flow smoothness, reduce the noise, and improve the user experience. Optionally, the arc radius R1 can be 5mm, 6mm, 8mm, etc., which is not limited in the embodiment.

[0118] Please refer to FIGS. 7-9, in an embodiment, the volute tongue structure 30 further comprises a plurality of flow guide ribs 35, which are spaced apart and protrude on the windward surface 32 along the extension direction of the volute tongue structure 30, and the flow guide ribs 35 are connected to at least the first volute tongue section 321 and the transition section 323.

[0119] The air flow blown by the fan wheel 50 in the working process is fast in flow rate, which is easy to produce noise. The embodiment spaces a plurality of flow guide ribs 35 on at least the windward surface 32, so that the air flow with noise is separated at least when flowing through the windward surface 32, and compared with the air flow directly impacting the entire windward surface 32, the interference area of the air flow with the surface of the flow guide rib 35 is smaller, thereby reducing the noise to improve the user experience. In addition, the arrangement direction (left-right direction XX) of the plurality of flow guide ribs 35 is parallel to the axial direction of the fan wheel 50, and the extension direction of the flow guide rib 35 is perpendicular to the axial direction of the fan wheel 50, so that under the flow guiding effect of the plurality of flow guide ribs 35, the flow of the air flow in the axial direction can be reduced, thereby reducing the pressure loss of the air flow in the flow process to the air outlet 121.

[0120] In the embodiment, the flow guide ribs 35 are arranged on at least the windward surface 32 and connected to at least the first volute tongue section 321 and the transition section 323, to guide the air flow flowing through the windward surface 32 and reduce the noise. The shape of the profile line of the flow guide rib 35 is configured as a wave shape, a polyline, or a single arc line shape that rises away from the volute tongue body, which is not limited in the embodiment. Optionally, the flow guide rib 35 can be an integral structure with the rest of the volute tongue structure 30, for example, by one-piece injection molding, so that the firmness of the structure as a whole can be improved, and the assembly steps can be reduced. Of course, the flow guide rib 35 can also be a separate structure with other structures of the volute tongue structure 30, and is fixed by bonding or buckling connection, etc.

[0121] Of course, the guide vanes 35 can also not only cover part of the windward surface 32, but also can be partially arranged in the leading edge guide section 33 when the vortex finder structure 30 comprises the leading edge guide section 33. Specifically, each guide vane 35 is configured to comprise a windward vane section 353 and a leading vane section 351, the leading vane section 351 is arranged in the leading edge guide section 33, and the windward vane section 353 is arranged at least in the first vortex finder section 321 and the transition section 323. In this way, by arranging the leading vane section 351, the interference area of the airflow blowing to the leading edge guide section 33 can also be reduced, thereby reducing the noise and reducing the along-the-way airflow loss.

[0122] Please refer to FIG. 7, in an embodiment, the windward vane section 353 has an arc-shaped profile line, the profile line of the windward vane section 353 is arranged corresponding to the profile lines of the first vortex finder section 321 and the transition section 323, and the profile line of the windward vane section 353 extends backward no more than the second vortex finder section 325, further, the profile line of the windward vane section 353 can be terminated backward at the end point of the profile line of the transition section 323 (also the starting point of the front end of the arc-shaped profile line of the second vortex finder section 325); or the profile line of the windward vane section 353 can be terminated backward at the inflection point of the arc-shaped profile line of the second vortex finder section 325; or the profile line of the windward vane section 353 can be terminated backward at the end point of the arc-shaped profile line of the second vortex finder section 325; or the profile line of the windward vane section 353 can be terminated backward at the inflection point of the arc-shaped profile line of the second vortex finder section 325. The profile line of the windward vane section 353 is arranged corresponding to the profile lines of the first vortex finder section 321 and the transition section 323, that is, the concave-convex form of the windward vane section 353 is the same as the profile lines of the first vortex finder section 321 and the transition section 323, for example, the first vortex finder section 321 is arranged in an arc shape, and the windward vane section 353 is also arranged in an arc shape, and it is not limited that the curvature of the windward vane section 353 is the same as the profile lines of the first vortex finder section 321 and the transition section 323. In this way, the airflow has a relatively consistent guiding effect when flowing through the windward vane section 353 as the first vortex finder section 321 and the transition section 323, and the airflow continues to flow to the second vortex finder section 325 when flowing out of the windward vane section 353, thereby ensuring the continuity of airflow guiding, reducing the extension length of each guide vane 35, thereby reducing the material usage of the guide vanes 35, and reducing the production cost of the vortex finder structure 30.

[0123] In an embodiment, the air guide fin section 351 has an arc-shaped profile line, and the profile line of the air guide fin section 351 is arranged correspondingly to the profile line of the leading edge air guide section 33, so that when the air flow flows through the air guide fin section 351, the air guide effect is consistent with that of the leading edge air guide section 33, and the air flow is divided, and the noise is reduced. The arc-shaped profile line of the air guide fin section 351 ends at the end point of the profile line of the leading edge air guide section 33, and when the air flow flows out of the air guide fin section 351, the air flow continues to flow to the air guide surface 31, thereby ensuring the continuity of the air flow guide, and the air guide fin 35 does not occupy the space of the air duct 15, the extension length of each air guide fin 35 is reduced, thereby reducing the material usage of the air guide fin 35, and reducing the production cost of the volute tongue structure 30

[0124] As shown in FIG. 7, the distance between the top surface of the windward fin section 353 and the windward surface 32 gradually decreases from the first volute tongue section 321 to the end point of the transition section 323. Since the air flow speed near the first volute tongue section 321 is fast, the air flow impact is strong, and thus the noise is large. The height of the windward fin section 353 at the first volute tongue section 321 is high, which can better divide the air flow and reduce the noise. Along the end point close to the transition section 323, the air flow tends to be smooth, and the windward fin section 353 can gradually decrease. In this way, a better air flow guide effect can be achieved, the noise is reduced, and the air between the windward surface 32 and the wind wheel 50 is occupied as little as possible, thereby ensuring the return air volume.

[0125] Similarly, the distance between the top surface of the air guide fin section 351 and the surface of the leading edge air guide section 33 gradually decreases from the first volute tongue section 321 to the air guide surface 31. The air flow speed near the first volute tongue section 321 is fast, the air flow impact is strong, and thus the noise is large. The higher height of the air guide fin section 351 at this position can better guide and divide the air flow, and reduce the noise. Away from the first volute tongue section 321, the air guide fin section 351 gradually decreases. In this way, the air flow can be better guided to flow to the air guide surface 31, the noise is reduced, and the space of the air duct 15 is occupied as little as possible.

[0126] Please refer to FIG. 7 and FIG. 9, in a specific embodiment of the present application, along the extension direction of the volute tongue structure 30, the distance between the adjacent two air guide fins 35 is d1, and the relationship 2mm≤d1≤4mm is satisfied. It can be understood that the larger the distance d1 between the air guide fins 35, the sparser the air guide fins 35, and vice versa. If the distance d1 is greater than 4mm, the distance between the adjacent two air guide fins 35 is too large, the air flow is not strong, the axial flow of the air flow is easily caused, the noise is caused, and the air flow smoothness is reduced. If the distance d1 is less than 2mm, the interference area between the air guide fins 35 and the air flow is increased, and the noise reduction effect is not good. Therefore, in order to ensure the smooth flow of the air flow and reduce the noise, the present embodiment limits 2mm≤d1≤4mm, and d1 can be selected as 2mm, 2.8mm, 3mm, etc.

[0127] Further, the width of the guide vane 35 along the extension direction of the volute tongue structure 30 is d2, which satisfies the relationship: 1mm≤d2≤3mm. If the width d2 is greater than 3mm, the interference area between the guide vane 35 and the airflow will increase, so that the good noise reduction effect cannot be achieved. If the width d2 is less than 1mm, the guide vane 35 is difficult to be processed and shaped, and the strength of the guide vane 35 itself is low. Therefore, in order to facilitate processing and effectively reduce noise, the embodiment limits 1mm≤d2≤3mm, wherein d1 can be selected as 1mm, 1.5mm, 2mm or 2.5mm, etc.

[0128] Further, the distance between the top surface of the guide vane 35 and the surface of the volute tongue structure 30 can be limited to d3, which satisfies the relationship: 2mm≤d3≤4mm. It can be understood that if the distance d3 is greater than 4mm, the tooth depth of the guide vane 35 is too large. When the gap between the surface of the volute tongue structure 30 and the wind wheel 50 is constant, the too large tooth depth indicates that the gap between the guide vane 35 and the wind wheel 50 is too small, the airflow speed is too fast, the noise is large, and the airflow is unstable, which easily affects the air return efficiency. If the distance d3 is less than 2mm, the flow guiding effect of the guide vane 35 is not obvious. Therefore, in order to improve the stability of the airflow and effectively reduce the noise, the embodiment limits 2mm≤d3≤4mm, wherein d3 can be selected as 2mm, 3mm or 3.5mm, etc.

[0129] Please refer to FIG. 7, in an embodiment, the rear edge air guide section 34 is connected to the second volute tongue section 325 and extends away from the second volute tongue section 325. In the embodiment, the rear edge air guide section 34 extends downward away from the second volute tongue section 325, which has a continuous guiding effect on the airflow passing through the second volute tongue section 325. The profile line of the rear edge air guide section 34 is a straight line in the projection along the extension direction of the volute tongue structure 30. The distance between the rear edge air guide section 34 and the wind wheel 50 gradually increases, so that the airflow is buffered, air supply is facilitated, and the air return efficiency is improved.

[0130] Further, the rear edge air guide section 34 is tangent to the second volute tongue section 325, so that the airflow flows from the second volute tongue section 325 to the rear edge air guide section 34 more smoothly, reduces airflow turbulence, and improves aerodynamic efficiency.

[0131] Please refer to FIG. 2 and FIG. 3 again, in an embodiment, the shell 10 includes a cabinet 11, a panel 12, a bottom plate 13 and a water collecting tray 14.

[0132] The cabinet 11 can be an alloy or metal material such as aluminum or steel to meet the requirements of structural strength and long service life, etc. Of course, the cabinet 11 can also be a plastic material to meet the requirement of light weight, etc., which is not limited in the present application. The cabinet 11 can play a protection role and be connected and adapted to the connecting structure of the indoor environment.

[0133] The bottom of the shell 11 is open, and the panel 12 is arranged on the opening. The air inlet 122 and the air outlet 121 are arranged on the panel 12 in a spaced manner. The panel 12 is usually detachably connected to the bottom of the shell 11, so that the panel 12 can be easily disassembled. In the later use process of the indoor unit 100, when the electrical elements in the shell 11 fail, the panel 12 can be disassembled, and the electrical elements in the shell 11 can be repaired. The connection between the panel 12 and the shell 11 can be through threaded fasteners or buckles. Here, the connection between the panel 12 and the shell 11 is not limited.

[0134] The bottom plate 13 and the water pan 14 are arranged in the shell 11, and the bottom plate 13 is located above the water pan 14. The shell 11, the bottom plate 13 and the water pan 14 cooperate to form an air duct 15. The volute tongue structure 30 is connected to the water pan 14.

[0135] In the embodiment, the volute tongue structure 30 can be an integral component, which can be made of metal or plastic to improve the structural integrity.

[0136] Referring to FIGS. 8-10, in another embodiment, the volute tongue structure 30 includes a first sub-component 301 connected to a second sub-component 303. The first sub-component 301 is connected to the water pan 14, and the second sub-component 303 is detachably connected to at least one of the water pan 14 and the first sub-component 301. The air guide surface 31 is arranged on the side of the first sub-component 301 away from the fan wheel 50, and the windward surface 32 is arranged on the side of the second sub-component 303 facing the fan wheel 50. In this way, the volute tongue structure 30 is formed by the cooperation of the first sub-component 301 and the second sub-component 303 arranged in a split manner. The two components can be connected by screws or buckles to facilitate later maintenance and replacement.

[0137] For example, the second sub-component 303 is detachably connected to the water pan 14, and the two components can be connected by at least one of buckles or bolts to improve the connection stability. Further, the water pan 14 and the first sub-component 301 are an integral structure. In this way, not only the installation steps are saved, but also the structural strength of the water pan 14 and the first sub-component 301 is improved, which is convenient for production.

[0138] As shown in FIG. 8, in an embodiment, the first sub-member 301 and the second sub-member 303 enclose a closed hollow cavity 305. It can be understood that the closed hollow cavity 305 can include a first half cavity and a second half cavity, the first half cavity is enclosed by the first sub-member 301, and the second half cavity is enclosed by the second sub-member 303, so as to form the closed hollow cavity 305. Of course, the closed hollow cavity 305 can also be formed by the first sub-member 301 alone, or by the second sub-member 303 alone, which is not limited in the present application. In this way, compared with the non-hollow form between the first sub-member 301 and the second sub-member 303, the embodiment can reduce the material of the first sub-member 301 and the second sub-member 303, reduce the cost, and reduce the weight, so that the overall weight of the indoor unit 100 is reduced, and the demolding is facilitated, and the processing efficiency is improved.

[0139] The above is the explanation and description of the specific structure of the indoor unit 100 in the embodiments of the present application. It can be understood that, since the heating and ventilation system of the present application adopts all the technical solutions of the above-mentioned embodiments, it at least has all the effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here.

[0140] The same or similar reference numerals in the drawings of the embodiments of the present application correspond to the same or similar parts; in the description of the present application, it should be understood that, if the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right" and the like are based on the orientations or positional relationships shown in the drawings, they are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationships in the drawings are only used for exemplary illustration, and cannot be understood as a limitation on the present application, and for those skilled in the art, the specific meanings of the above-mentioned terms can be understood according to the specific circumstances.

[0141] The above is only the preferred embodiment of the present application, and does not limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An indoor unit, wherein, The indoor unit comprises a shell, a wind wheel and a volute tongue structure. The shell is provided with an air outlet and an air inlet at the bottom, and a wind channel is formed to communicate the air inlet and the air outlet. The wind wheel is arranged in the wind channel. The volute tongue structure is arranged between the wind wheel and the air outlet, and extends along the axial direction of the wind wheel. The volute tongue structure has a guide surface away from the wind wheel and a windward surface towards the wind wheel. The windward surface comprises: a first volute tongue segment arranged in an arc profile line towards the wind wheel; a second volute tongue segment arranged in an arc profile line towards the wind wheel and spaced from the first volute tongue segment; and a transition segment connecting the first volute tongue segment and the second volute tongue segment. The airflow passing through the windward surface can pass through the first volute tongue segment, the transition segment and the second volute tongue segment in sequence. In the projection along the extension direction of the volute tongue structure, the profile line of the transition segment is lower than the tangent line of the first volute tongue segment and the second volute tongue segment, or the profile line of the transition segment is flush with the tangent line of the first volute tongue segment and the second volute tongue segment.

2. The indoor unit of claim 1, wherein, In the projection along the extension direction of the volute tongue structure, the profile line of the transition segment is lower than the tangent line of the first volute tongue segment and the second volute tongue segment, and the transition segment is an arc segment arching away from the wind wheel.

3. The indoor unit of claim 1, wherein, In the direction from the first volute tongue segment to the second volute tongue segment, the distance between the windward surface and the outer edge of the wind wheel is constant, or gradually decreases, or first increases and then decreases.

4. The indoor unit of claim 1, wherein, The first volute tongue segment and the outer edge of the wind wheel have a first gap h1, and the first gap satisfies the relationship: 6mm≤h1≤12mm; and / or The second volute tongue segment and the outer edge of the wind wheel have a second gap h2, and the second gap satisfies the relationship: 4mm≤h2≤10mm.

5. The indoor unit of claim 4, wherein, The first gap h1 is greater than the second gap h2.

6. The indoor unit of claim 1, wherein, The first volute tongue segment, the transition segment and the second volute tongue segment are smoothly connected.

7. The indoor unit of claim 1, wherein, In the height direction of the indoor unit in the installed state, the first volute tongue segment is higher than the second volute tongue segment.

8. The indoor unit of claim 1, wherein, The curvature of the first volute tongue segment is greater than the curvature of the second volute tongue segment.

9. The indoor unit of any one of claims 1 to 8, wherein, In the cross section of the indoor unit perpendicular to the axial direction of the wind wheel, the center of the wind wheel is defined as O, the starting point of the first volute tongue segment is defined as N, and the ending point of the second volute tongue segment is defined as L. In the cross section of the indoor unit perpendicular to the axial direction of the wind wheel, the starting point of the second volute tongue segment is defined as M, and the envelope angle of the second volute tongue segment is defined as ∠MOL, which satisfies the relationship: 2°≤∠MOL≤10°.

10. The indoor unit of claim 9, wherein, The volute tongue structure further comprises a leading edge guide segment connecting the first volute tongue segment and the guide surface.

11. The indoor unit of any one of claims 1 to 8, wherein, In the projection along the extension direction of the volute tongue structure, the profile line of the guide surface is arranged in a straight line, the profile line of the leading edge guide segment is arranged in an arc, and the ending point of the profile line of the leading edge guide segment overlaps with the starting point of the profile line of the guide surface.

12. The indoor unit of claim 11, wherein, The profile line of the guide surface is tangent to the arc profile line of the leading edge guide segment.

13. The indoor unit of claim 12, wherein, ​ 14. The indoor unit of claim 12, wherein, The front edge air guide section has an arc radius R1, satisfying the relationship: 5mm≤R1≤9mm.

15. The indoor unit of any one of claims 1 to 14, wherein, The volute tongue structure further comprises a plurality of flow guide ribs, which are arranged on at least the windward surface in the extension direction of the volute tongue structure, and the flow guide ribs are connected to at least the first volute tongue section and the transition section.

16. The indoor unit of claim 15, wherein, Further comprising a front edge air guide section connecting the first volute tongue section and the air guide surface, each of the flow guide ribs is configured to comprise a windward rib section and a wind guide rib section, the wind guide rib section is arranged in the front edge air guide section, and the windward rib section is arranged in at least the first volute tongue section and the transition section.

17. The indoor unit of claim 16, wherein, The windward rib section has an arc-shaped profile line, the profile line of the windward rib section is arranged corresponding to the profile line of the first volute tongue section and the transition section, and the profile line of the windward rib section ends at the end point of the profile line of the transition section.

18. The indoor unit of claim 16, wherein, The wind guide rib section has an arc-shaped profile line, the profile line of the wind guide rib section is arranged corresponding to the profile line of the front edge air guide section, and the arc-shaped profile line of the wind guide rib section ends at the end point of the profile line of the front edge air guide section.

19. The indoor unit of claim 16, wherein, The distance between the top surface of the windward rib section and the windward surface gradually decreases from the first volute tongue section to the end point of the transition section; and / or, The distance between the top surface of the wind guide rib section and the surface of the front edge air guide section gradually decreases from the first volute tongue section to the air guide surface.

20. The indoor unit of claim 15, wherein, The distance between the top surface of the windward rib section and the windward surface gradually decreases from the first volute tongue section to the end point of the transition section; and / or, The distance between the top surface of the wind guide rib section and the surface of the front edge air guide section gradually decreases from the first volute tongue section to the air guide surface. The distance between the top surface of the windward rib section and the windward surface gradually decreases from the first volute tongue section to the end point of the transition section; and / or, 21. The indoor unit as claimed in claim 1, wherein, The distance between the top surface of the wind guide rib section and the surface of the front edge air guide section gradually decreases from the first volute tongue section to the air guide surface. Further comprising a rear edge air guide section connecting the second volute tongue section and extending away from the second volute tongue section in the direction; 22. The indoor unit of claim 21, wherein, Wherein, the profile line of the rear edge air guide section is arranged in a straight line in the extension direction of the volute tongue structure.

23. The indoor unit of any one of claims 1 to 22, wherein, The rear edge air guide section is tangent to the second volute tongue section. The indoor unit further comprises a heat exchanger, and the shell comprises: A shell with an open bottom; A bottom plate and a water collecting tray arranged in the shell, wherein the bottom plate is above the water collecting tray, and the bottom plate, the water collecting tray and the shell cooperatively define the air duct, the heat exchanger is arranged in the air duct and is upstream of the fan wheel, and the volute tongue structure is connected to the water collecting tray; and 24. The indoor unit of claim 23, wherein, A panel covering the opening and provided with the air inlet and the air outlet. The volute tongue structure comprises a first sub-component and a second sub-component connected to each other, the first sub-component is connected to the water collecting tray, and the second sub-component is detachably connected to the water collecting tray and / or the first sub-component; 25. The indoor unit of claim 24, wherein, The air guide surface is arranged on the side of the first sub-component away from the fan wheel, and the windward surface is arranged on the side of the second sub-component facing the fan wheel.

26. A heating and ventilation system wherein, The first sub-component and the second sub-component enclose a closed hollow cavity. Comprise: An outdoor unit; And The indoor unit according to any one of claims 1 to 25, having a circulating refrigerant with the outdoor unit.

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