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 and at least two cross-flow fan wheels. An air inlet and an air outlet are spaced apart in the bottom surface, and an air duct communicated with the air inlet and the air outlet is formed in the housing. The at least two cross-flow fan wheels are arranged in the air duct and are spaced apart in the length extension direction of the air outlet. Each cross-flow fan wheel comprises a plurality of groups of blades, each group of blades comprise a plurality of blades, and the plurality of blades in one group are arranged at intervals in the circumferential direction of the rotation center axis of the cross-flow fan wheel. When viewed in a direction perpendicular to the axial direction of the cross-flow fan wheel, each blade in a group of blades is obliquely arranged relative to the axial direction.

Description

Indoor unit and HVAC system

[0001] Related applications

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on March 25, 2024, with application number 2024103451815 and invention name “Indoor unit and HVAC system”, and the Chinese patent application filed with the China Patent Office on March 25, 2024, with application number 2024205865558 and invention name “Indoor unit and HVAC system”. The full text of the above documents are hereby incorporated by reference. Technical Field

[0003] The present application relates to the technical field of air conditioning, and in particular to an indoor unit and a heating and ventilation system having the same. Background Art

[0004] Indoor airflow organization is an important factor in evaluating the quality of HVAC systems. For the indoor unit of a comfort HVAC system, a reasonable air supply method (air supply distance and air supply width) is of great significance in terms of indoor air environment, human comfort and indoor unit energy saving.

[0005] In the related art, the indoor unit of the HVAC system, such as the ceiling unit, is equipped with a cross-flow fan to achieve indoor air supply. However, the ceiling unit in the existing technology uses a relatively simple air supply method using a cross-flow fan, and is unable to set an adaptive air supply distance and air supply width according to different actual indoor scenes, which limits the use scenarios of the indoor unit and cannot meet different air supply requirements in the actual environment. Summary of the Invention

[0006] The embodiments of the present application provide an indoor unit and a HVAC system, which can solve the problem in the prior art that the indoor unit has a single air supply and cannot meet different air supply requirements in actual environments.

[0007] In a first aspect, an embodiment of the present application provides an indoor unit, comprising:

[0008] A housing having an air inlet and an air outlet spaced apart on the bottom surface, and an air duct communicating with the air inlet and the air outlet formed inside the housing; and

[0009] At least two cross-flow impellers, the at least two cross-flow impellers being disposed in the air duct and spaced apart in a longitudinal extension direction of the air outlet;

[0010] The crossflow wind wheel includes multiple groups of blades, each group of blades has multiple blades, and the multiple blades in a group are arranged at intervals along the circumference of the rotation center axis of the crossflow wind wheel. When observed along the axial direction perpendicular to the crossflow wind wheel, each blade in a group of blades is inclined relative to the axial direction.

[0011] In some embodiments, the blades of two adjacent crossflow impellers have the same inclination direction.

[0012] In some embodiments, the blades of two adjacent crossflow impellers have different inclination directions.

[0013] In some embodiments, each of the cross-flow wind wheel has a plurality of fixed walls spaced apart along the axial direction, a group of blades is provided between each two adjacent fixed walls, each blade has an air outlet tail end away from the central axis of rotation of the cross-flow wind wheel, the air outlet tail end includes a plurality of air outlet portions spaced apart, and an air supply incision is defined between two adjacent air outlet portions.

[0014] In some embodiments, when viewed along an axial direction perpendicular to the crossflow impeller, the projected distances from the plurality of air outlet portions of each blade in each group to the rotation center axis increase sequentially.

[0015] In some embodiments, when viewed along an axial direction perpendicular to the crossflow impeller, the projected distances from the plurality of air outlet portions of each blade in each group to the rotation center axis decrease sequentially.

[0016] In some embodiments, the air-supply slits of different blades of the same crossflow impeller are arranged in a circle along the circumference of the crossflow impeller, and multiple circles of the air-supply slits are arranged along the axial direction of the crossflow impeller;

[0017] And / or, the cross-section of each of the air-replenishing incisions parallel to the length direction of the blade is rectangular, triangular or trapezoidal.

[0018] In some embodiments, on two adjacent groups of blades, there is a misalignment angle A between the two adjacent blades and the axis of the crossflow impeller in their extension directions, and A is less than or equal to 8 degrees and greater than or equal to 5 degrees.

[0019] In some embodiments, on two adjacent groups of blades, there is a misalignment angle A between the two adjacent blades and the axis of the crossflow impeller in their extension directions, and A is less than or equal to 8 degrees and greater than or equal to 5 degrees.

[0020] In some embodiments, two adjacent crossflow impellers have different numbers of blades.

[0021] In some embodiments, the indoor unit further includes a heat exchanger, which is disposed in the air duct and located between the crossflow impeller and the air inlet.

[0022] In some embodiments, the housing includes a casing, a panel, and a water receiving tray. The bottom of the casing is open, the panel cover is provided at the opening, the air inlet and the air outlet are arranged on the panel at intervals, the heat exchanger, the crossflow impeller, and the water receiving tray are all provided in the casing, and the casing, the panel, and the water receiving tray cooperate to form the air duct.

[0023] The water receiving tray is located below the wind wheel and the heat exchanger to collect condensed water generated by the heat exchanger.

[0024] In a second aspect, an embodiment of the present application provides a HVAC system, which includes an outdoor unit and an indoor unit as described above, wherein the outdoor unit is connected to the indoor unit.

[0025] In a third aspect, an embodiment of the present application provides an indoor unit, comprising:

[0026] A housing having an air inlet and an air outlet spaced apart on the bottom surface, and an air duct communicating with the air inlet and the air outlet formed inside the housing; and

[0027] At least two cross-flow impellers, the at least two cross-flow impellers being disposed in the air duct and spaced apart in a longitudinal extension direction of the air outlet;

[0028] The crossflow wind wheel includes multiple groups of blades, each group of blades has multiple blades, and the multiple blades in a group are arranged at intervals along the circumference of the rotation center axis of the crossflow wind wheel.

[0029] Each of the blades has an air outlet tail end away from the rotation center axis of the crossflow impeller, and the air outlet tail end includes a plurality of air outlet portions arranged in sequence and spaced apart, and an air supply cutout is defined between two adjacent air outlet portions.

[0030] When observed along the axial direction perpendicular to the crossflow impeller, the projected distances from the multiple air outlet portions of each blade in each group to the rotation center axis increase or decrease in sequence.

[0031] The air-supply slits of different blades of the same crossflow impeller are arranged in a circle along the circumference of the crossflow impeller, and multiple circles of the air-supply slits are arranged along the axial direction of the crossflow impeller;

[0032] And / or, the cross-section of each of the air-replenishing incisions parallel to the length direction of the blade is rectangular, triangular or trapezoidal.

[0033] In some embodiments, on two adjacent groups of blades, there is an offset angle A between the two adjacent blades in their extension directions and the axis of the crossflow impeller, and A is less than or equal to 8 degrees and greater than or equal to 5 degrees;

[0034] And / or, the number of blades of two adjacent crossflow wind wheels is different.

[0035] In some embodiments, the indoor unit further includes a heat exchanger, which is disposed in the air duct and located between the crossflow impeller and the air inlet.

[0036] In some embodiments, the housing includes a casing, a panel, and a water receiving tray. The bottom of the casing is open, the panel cover is provided at the opening, the air inlet and the air outlet are arranged on the panel at intervals, the heat exchanger, the crossflow impeller, and the water receiving tray are all provided in the casing, and the casing, the panel, and the water receiving tray cooperate to form the air duct.

[0037] The water receiving tray is located below the wind wheel and the heat exchanger to collect condensed water generated by the heat exchanger.

[0038] In a fourth aspect, an embodiment of the present application provides an indoor unit, comprising:

[0039] A housing having an air inlet and an air outlet spaced apart on the bottom surface, and an air duct communicating with the air inlet and the air outlet formed inside the housing; and

[0040] At least two cross-flow impellers, the at least two cross-flow impellers being disposed in the air duct and spaced apart in a longitudinal extension direction of the air outlet;

[0041] The crossflow wind wheel includes multiple groups of blades, each group of blades has multiple blades, and the multiple blades in a group are arranged at intervals along the circumference of the rotation center axis of the crossflow wind wheel.

[0042] Each of the blades has an air outlet tail end away from the rotation center axis of the crossflow impeller, the air outlet tail end includes a plurality of air outlet portions arranged in sequence and spaced apart, and an air supply notch is defined between two adjacent air outlet portions;

[0043] When observed along the axial direction perpendicular to the cross-flow wind wheel, of two adjacent cross-flow wind wheels, the projected distances from the multiple air outlets in each blade in each group of one cross-flow wind wheel to the rotation center axis increase sequentially, while the projected distances from the multiple air outlets in each blade in each group of the other cross-flow wind wheel to the rotation center axis decrease sequentially.

[0044] The air-supply slits of different blades of the same crossflow impeller are arranged in a circle along the circumference of the crossflow impeller, and multiple circles of the air-supply slits are arranged along the axial direction of the crossflow impeller;

[0045] And / or, the cross-section of each of the air-replenishing incisions parallel to the length direction of the blade is rectangular, triangular or trapezoidal.

[0046] In some embodiments, on two adjacent groups of blades, there is an offset angle A between the two adjacent blades in their extension directions and the axis of the crossflow impeller, and A is less than or equal to 8 degrees and greater than or equal to 5 degrees;

[0047] And / or, the number of blades of two adjacent crossflow wind wheels is different.

[0048] In some embodiments, the indoor unit further includes a heat exchanger, which is disposed in the air duct and located between the crossflow impeller and the air inlet.

[0049] In some embodiments, the housing includes a casing, a panel, and a water receiving tray. The bottom of the casing is open, the panel cover is provided at the opening, the air inlet and the air outlet are arranged on the panel at intervals, the heat exchanger, the crossflow impeller, and the water receiving tray are all provided in the casing, and the casing, the panel, and the water receiving tray cooperate to form the air duct.

[0050] The water receiving tray is located below the wind wheel and the heat exchanger to collect condensed water generated by the heat exchanger.

[0051] The indoor unit and HVAC system according to the embodiments of the present application have an air inlet and an air outlet spaced apart on the bottom surface of a housing, and an air duct connecting the air inlet and the air outlet is formed within the housing. Furthermore, two crossflow impellers are disposed within the air duct, and the blades of the crossflow impellers are twisted along their axial directions, with the twist directions of the blades of adjacent crossflow impellers being different. Thus, the indoor unit according to the embodiments has at least the following technical effects:

[0052] First, the air inlet and outlet are both set on the bottom surface of the shell, so that the air intake and air discharge are carried out on the same side of the indoor unit. Compared with the design of multi-side air inlet and outlet, the air flow path is shorter, and it is more convenient to connect the air inlet and outlet with the indoor environment during installation, reducing the complexity of installation. Secondly, on the basis of setting the air inlet and outlet on the same side of the indoor unit, the inclined blades can change the direction and speed of the air flow. Then, according to the actual indoor scene, by adjusting the blade inclination angle and the coordinated operation of multiple cross-flow impellers, the air supply distance and air supply width can be flexibly adjusted. This broadens the use scenarios of the indoor unit and meets the diverse air supply needs in the actual environment. It has positive significance in optimizing the indoor air environment, improving human comfort, and helping the indoor unit save energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] 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.

[0054] FIG1 is a schematic structural diagram of an indoor unit according to an embodiment of the present application;

[0055] FIG2 is a schematic diagram of an exploded structure of an indoor unit according to an embodiment of the present application;

[0056] FIG3 is a schematic diagram of the cross-sectional structure along the AA plane in FIG1 ;

[0057] FIG4 is a schematic structural diagram of an embodiment of two crossflow impellers of an indoor unit of the present application;

[0058] FIG5 is a partial enlarged view of point A in FIG4 ;

[0059] FIG6 is a schematic structural diagram of another embodiment of two crossflow impellers of the indoor unit of the present application;

[0060] FIG7 is a partial enlarged view of point B in FIG6;

[0061] FIG8 is a schematic structural diagram of the crossflow impeller shown in FIG2 ;

[0062] FIG9 is a schematic diagram of the assembly of two crossflow impellers of the indoor unit of the present application from an axial perspective;

[0063] FIG10 is an exploded schematic diagram of two crossflow impellers of the indoor unit of the present application from an axial perspective;

[0064] FIG11 is a schematic assembly diagram of a partial structure of a crossflow impeller of an indoor unit of the present application from an axial perspective;

[0065] FIG12 is a schematic assembly diagram of a partial structure of a crossflow impeller of an indoor unit of the present application from another axial perspective;

[0066] FIG13 is an exploded schematic diagram of a partial structure of a crossflow impeller of an indoor unit of the present application from an axial perspective;

[0067] FIG14 is a schematic diagram of the cooperation between the crossflow impeller and the volute tongue shown in FIG2 ;

[0068] FIG15 is a schematic diagram of an embodiment of a crossflow impeller of an indoor unit of the present invention, viewed along a direction perpendicular to the axial direction of the crossflow impeller;

[0069] FIG16 is a schematic diagram of another embodiment of the crossflow impeller of the indoor unit of the present application, viewed along a direction perpendicular to the axial direction of the crossflow impeller.

[0070] Explanation of the accompanying reference numerals: 100, indoor unit; 10, casing; 11, volute; 111, volute body; 112, guide rib; 113, guide groove; 10a, air inlet; 10b, air outlet; 12, casing; 13, panel; 14, water collection tray; 20, cross-flow impeller; L1, central axis of rotation; L2, axial direction; 21, end cover; 221, fixed wall; 222, blade; 2221, air outlet tail end; 222a, air outlet part; 222b, air supply cutout; 30, coupling; 40, heat exchanger; 50, drive motor; 60, support seat; 70, buffer member.

[0071] 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

[0072] 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.

[0073] 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.

[0074] In the description of this application, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to 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.

[0075] 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.

[0076] Referring to Figure 1 , an embodiment of the present application provides a HVAC system. In this embodiment, the HVAC equipment includes, but is not limited to, air conditioners, VRFs, and heat pumps, and can be used in large-scale locations such as shopping malls and office buildings. The HVAC system may include an indoor unit 100, an outdoor unit (not shown), and a connecting pipe (not shown). The indoor unit 100 is connected to the outdoor unit via the connecting pipe, forming a circulation flow path between the indoor unit 100 and the outdoor unit.

[0077] In some actual usage scenarios, the indoor unit 100 of the present application can be installed indoors, and the outdoor unit is responsible for cooling or heating, and transports refrigerant or chilled water and other media through connecting pipes. After the refrigerant or chilled water and other media exchange heat with the indoor air and outdoor air respectively, the indoor unit 100 is responsible for transporting cold air or hot air into the room to achieve the effect of cooling or heating.

[0078] Specifically, the indoor unit 100 can include one of a ceiling unit, a duct unit and a wall-mounted air-conditioning indoor unit 100, wherein the ceiling unit is usually embedded in the ceiling in the form of a suspended ceiling, so as to hide the ceiling unit through the ceiling. In this way, the ceiling unit has a better hiding effect and is more beautiful than other forms of the indoor unit 100. This embodiment does not specifically limit the specific form of the indoor unit 100.

[0079] 1 to 3 , in some embodiments, the indoor unit 100 includes a housing 10 , a heat exchanger 40 , and a crossflow impeller 20 . The heat exchanger 40 and the crossflow impeller 20 are both disposed in an air duct of the housing 10 .

[0080] The outer contour of the housing 10 can be set in a rectangular block shape, and the material of the housing 10 can be metal, which has advantages such as good strength, lightness, and corrosion resistance. Of course, the material of the housing 10 can also be plastic, which has advantages such as light weight, low cost, and easy processing and molding. This embodiment does not limit the shape and material of the housing 10. When the indoor unit 100 is installed indoors, the bottom surface can be located on the ceiling and facing the indoor environment. The bottom surface of the housing 10 is provided with an air inlet 10a and an air outlet 10b at intervals, and an air duct connecting the air inlet 10a and the air outlet 10b is formed inside the housing 10. This allows the indoor unit 100 to intake and exhaust air from the same side, which shortens the air flow path compared to a design with air inlet and outlet on multiple sides. It is also more convenient to connect the air inlet 10a and the air outlet 10b to the indoor environment during installation, reducing the complexity of installation. In addition, the housing 10 further includes a volute tongue 11, which is located between the crossflow impeller 20 and the air outlet 10b. The volute tongue 11 is used to divide the airflow sent to the air outlet 10b by the crossflow impeller 20 so that part of the airflow can flow smoothly to the air outlet 10b.

[0081] The heat exchanger 40 can have a variety of shapes, such as straight, V-shaped, curved, or wavy. The heat exchanger 40 is used to exchange heat with the gas passing through the heat exchanger 40, thereby cooling or heating the gas. For example, a plurality of refrigerant pipes are provided in the heat exchanger 40. When the gas passes through the heat exchanger 40, it exchanges heat with the refrigerant in the pipes, thereby changing the temperature of the gas. Specifically, during cooling, the gas exchanges heat with the refrigerant in the heat exchanger 40 to form low-temperature air, while during heating, the gas exchanges heat with the refrigerant in the heat exchanger 40 to form heated air. In some embodiments, the heat exchanger 40 is disposed in the air duct and is located between the crossflow impeller 20 and the air inlet 10a. In this way, the airflow entering the air inlet 10a will first exchange heat with the heat exchanger 40, and then pass through the crossflow impeller 20 and be blown into the indoor scene from the air outlet 10b. In this way, the heat exchanger 40 is disposed away from the air outlet 10b to reduce the interference of the heat exchanger 40 with the air outlet direction.

[0082] Referring to Figures 2 and 3 , in some structural configurations, the housing 10 includes a casing 12, a panel 13, and a water tray 14. The casing 12 can be made of alloys or metals such as aluminum and steel. These materials meet the structural strength requirements and ensure a long service life for the indoor unit 100. Of course, the casing 12 can also be made of plastic to achieve the advantage of being lighter in weight. This application does not impose any specific restrictions on the material of the casing 12. The casing 12 not only protects the internal components but also allows for compatible connection with the indoor environment. The bottom of the casing 12 is open, with the panel 13 covering the open area. The air inlet 10a and air outlet 10b are spaced apart on the panel 13. The panel 13 is detachably connected to the bottom of the casing 12. This design allows for easy removal of the panel 13 to access and repair the components within the casing 12 in the event of a malfunction in the electrical components of the indoor unit 100 during subsequent use. The panel 13 and the housing 12 can be connected in various ways, such as by threaded fasteners or by snap-on connections. This application does not impose any specific restrictions on the connection method.

[0083] The heat exchanger 40, the cross-flow impeller 20 and the water receiving pan 14 are all arranged inside the casing 12. The casing 12, the panel 13 and the water receiving pan 14 cooperate with each other to form an air duct. The water receiving pan 14 is located below the impeller and the heat exchanger 40, and its function is to receive the condensed water generated by the heat exchanger 40. During the operation of the indoor unit 100, a large amount of condensed water usually condenses on the surface of the heat exchanger 40. Generally, in order to prevent excessive condensed water from adhering to the surface of the heat exchanger 40 and affecting its performance, a water receiving pan 14 is provided below the bottom of the heat exchanger 40 to receive the condensed water, so as to prevent the condensed water from damaging the heat exchanger 40 and other components of the indoor unit 100 and ensure the normal operation of the indoor unit 100.

[0084] 2 and 3 , the crossflow impeller 20 has the advantages of energy saving, large air volume, low operating noise, and simple installation. Therefore, the crossflow impeller 20 is used to drive the airflow to improve the performance of the indoor unit 100. The crossflow impeller 20 can be arranged in a long cylindrical shape, and the crossflow impeller 20 includes blades 222. The cross-sectional shape of the blades 222 can be an airfoil shape, which can optimize the distribution of the airflow on the surface of the blades 222, making the airflow flowing through the surface of the blades 222 more uniform and reducing the turbulence of the airflow on the surface of the blades 222, thereby improving the overall aerodynamic performance of the crossflow impeller 20. For example, the airfoil shape can be a symmetrical airfoil, a flat-convex airfoil, or a concave-convex airfoil, etc., which is not limited in this embodiment. The material of the blade 222 can be plastic material, which has the advantages of light weight and corrosion resistance. For example, it can be specifically ASG (glass fiber reinforced AS resin) material. Of course, this embodiment is not limited to this. The material of the blade 222 can also be metal material, which has the advantages of high strength, so as to maintain long-term stable operation without deformation.

[0085] However, the existing ceiling unit adopts a relatively simple air supply method using a cross-flow fan 20, and cannot set an adaptive air supply distance and air supply width according to different actual indoor scenes, which limits the use scenario of the indoor unit 100 and cannot meet different air supply requirements in the actual environment.

[0086] 4 to 7 , based on this, in order to solve the above problem, the present application proposes that at least two cross-flow impellers 20 are provided in the air duct and spaced apart in the longitudinal extension direction of the air outlet 10b.

[0087] Among them, under high-speed rotation or heating conditions, the middle part of a single long wind wheel will produce a large deformation. Therefore, under the same length of the air outlet 10b, the single long wind wheel is designed to be two cross-flow wind wheels 20 spaced apart in the length extension direction of the air outlet 10b, so as to effectively reduce the possibility of deformation during the operation of the wind wheel. The cross-flow wind wheel 20 includes multiple groups of blades 222, each group of blades 222 has multiple blades, and the multiple blades 222 of a group are arranged at intervals along the circumferential direction of the rotation center axis L1 of the cross-flow wind wheel 20. When observed along the axial direction L2 perpendicular to the cross-flow wind wheel 20, each blade 222 in a group of blades 222 is tilted relative to the axial direction L2. Specifically, in the actual processing process, at least two of the following processing forms can be included to achieve the tilting of each blade 222 itself relative to the axial direction:

[0088] In the first form, the blade 222 is made of plastic and is formed by injection molding. During the demoulding process, a rotary demoulding method can be adopted. Specifically, during the demoulding process, the mold is rotated along the rotation axis, thereby forming an inclined shape relative to the axial direction during the demoulding process.

[0089] In the second form, after the blade 222 is processed, an external force is applied only to either end of the blade 222 along its length direction, so that the blade 222 is tilted relative to the axial direction; or an external force is applied in a clockwise direction to one end of the blade 222 along its length direction, and an external force is applied in a counterclockwise direction to the other end, so that the blade 222 is tilted relative to the axial direction.

[0090] In summary, the air inlet 10a and the air outlet 10b are both set on the bottom surface of the shell 10, so that the air intake and air discharge are performed on the same side of the indoor unit 100. Compared with the design of multi-side air inlet and outlet, the air flow path is shorter, and it is more convenient to connect the air inlet 10a and the air outlet 10b to the indoor environment during installation, reducing the complexity of installation. Secondly, on the basis of setting the air inlet and outlet on the same side of the indoor unit 100, the inclined blades 222 can change the direction and speed of the air flow, and then can achieve flexible adjustment of the air supply distance and air supply width according to the actual indoor scene by adjusting the inclination angle of the blades 222 and the coordinated operation of multiple cross-flow impellers 20, thereby broadening the use scenarios of the indoor unit 100 and meeting the diverse air supply needs in the actual environment. It has positive significance in optimizing the indoor air environment, improving human comfort, and helping the indoor unit 100 save energy.

[0091] 6 and 7 , in one structural form, the blades 222 of two adjacent crossflow impellers 20 have the same inclination direction. This enables the adjacent crossflow impellers 20 to guide the airflow in the same direction. Within the air duct, the airflow is influenced by the same-direction guidance of the adjacent crossflow impellers 20, forming a more concentrated and stable airflow beam. This concentrated and stable airflow beam can enhance the directionality of the air supply when passing through the air outlet 10b, thereby effectively increasing the air supply distance. At the same time, due to the concentration of the airflow, the energy loss of the airflow during the diffusion process can be reduced, which helps the indoor unit 100 save energy. In addition, the concentrated airflow can also increase the air circulation speed in specific areas of the room to a certain extent, optimize the indoor air environment, and enhance human comfort. Moreover, compared with designs with complex and variable inclination directions of the blades 222, this structure is simpler during the manufacturing and assembly process, reducing production difficulty and cost.

[0092] Referring to Figures 4 and 5 , in another structural form, the blades 222 of two adjacent crossflow impellers 20 have different inclinations. This allows the airflow passing through the two crossflow impellers 20 to be guided in different directions. As the airflow passes through adjacent crossflow impellers 20 with different inclinations, it undergoes differential changes in direction and speed, resulting in a complex and diverse airflow combination at the air outlet 10b. This diverse airflow combination greatly expands the air supply range, providing more comprehensive coverage of the indoor space and ensuring effective air conditioning in every corner. Furthermore, due to the mixing and interweaving of airflow in different directions, indoor air circulation is more complete, effectively avoiding air conditioning dead spots, further optimizing the indoor air environment, and enhancing overall human comfort. Furthermore, the interaction of airflows in different directions can disrupt the airflow boundary layer to a certain extent, reducing airflow separation and improving airflow delivery efficiency, thereby contributing to energy-saving operation of the indoor unit 100 in different air supply modes.

[0093] Referring to Figures 8 to 11 , in some structural forms, each crossflow impeller 20 has a plurality of fixed walls 221 spaced apart along the axial direction L2, with a set of blades 222 positioned between each two adjacent fixed walls 221. The blades 222 can be securely secured to the fixed walls 221 via ultrasonic welding. This welding method ensures the stability of the connection between the blades 222 and the fixed walls 221, ensuring that the blades 222 will not loosen or fall off during high-speed rotation of the crossflow impeller 20, thereby ensuring stable and efficient operation of the crossflow impeller 20. The blades 222 of the crossflow impeller 20 have an outlet tail end 2221 that is spaced away from the central axis of rotation of the crossflow impeller 20. It is understood that when air flows through the blades 222, it will eventually flow out of the outlet tail end 2221 and toward the volute tongue 11.

[0094] Referring to Figure 5, in some structural forms, the indoor unit 100 also includes a coupling 30, which is connected between two adjacent crossflow impellers 20. The coupling 30 is used to connect the two adjacent crossflow impellers 20 so that they can operate synchronously. In this way, the system can drive the two crossflow impellers 20 through the same drive motor 50, rather than requiring two independent drive motors 50. This design not only reduces the energy consumption of the system, but also reduces the maintenance cost of the system. Secondly, the design of the coupling 30 connecting the two crossflow impellers 20 simplifies the structure of the system, reducing the number and complexity of components. This helps to improve the reliability and stability of the system and reduce the possibility of failure. Referring to Figures 10 and 11, in addition, end caps 21 are provided at opposite ends of the crossflow impeller 20, and connection holes are provided on the end caps 21 to facilitate connection with the coupling 30 or the drive motor 50.

[0095] With reference to Figures 5, 12, and 13, the indoor unit 100 further includes a support base 60 and a buffer member 70. The support base 60 supports the coupling 30. The buffer member 70 is connected to the side of the support base 60 facing the heat exchanger 40 to elastically abut against the heat exchanger 40. The support base 60 primarily supports the coupling 30, ensuring its stability during operation. The buffer member 70 is connected to the side of the support base 60 facing the heat exchanger 40 to elastically abut against the heat exchanger 40. The buffer member 70 is typically made of silicone or rubber. Silicone offers excellent flexibility, weather resistance, and insulating properties. Its flexibility allows it to elastically deform when subjected to vibration and impact, effectively absorbing and dissipating vibration energy, preventing vibration transmission to the heat exchanger 40 and protecting the internal structure of the heat exchanger 40 from damage. Its weather resistance ensures that it maintains stable buffering performance under varying environmental conditions, such as indoor environments with large temperature and humidity fluctuations, and prevents rapid aging and deterioration due to environmental factors. Rubber also has excellent elasticity, allowing for quick rebound and effective vibration dampening. Rubber also possesses a certain degree of wear resistance, making it less susceptible to wear during frequent, long-term vibration dampening, thus ensuring the service life of the buffer member 70. When the indoor unit 100 is operating, vibrations may occur. The buffer member 70, made of silicone or rubber, effectively dampens these vibrations, reducing the mutual influence caused by vibration between the coupling 30 and the heat exchanger 40, further improving the stability of system operation, protecting the heat exchanger 40 and other related components, and extending the overall service life of the indoor unit 100.

[0096] 8 and 14 , in some structural forms, the air outlet tail end 2221 includes a plurality of spaced-apart air outlet portions 222a, with an air supply cutout 222b defined between two adjacent air outlet portions 222a. The air supply cutout 222b is configured to transition the airflow at the air supply cutout 222b from a laminar flow state to a turbulent flow state. As a result, as the airflow flows toward the volute tongue 11, the large vortex in the wake of the airflow can be transformed into multiple small vortices in advance. This not only reduces the intensity of the noise generated by the airflow as it flows toward the volute tongue 11, but also reduces the intensity of the noise generated when multiple small vortices impact the volute tongue 11 compared to when a large vortex impacts the volute tongue 11.

[0097] With reference to FIG. 15 , in some embodiments, when viewed along the axial direction L2 perpendicular to the crossflow impeller 20, the projected distances from the multiple air outlets 222a of each blade 222 in each group to the rotational center axis L1 increase sequentially. It should be noted that the projected distance here refers to the average distance from the multiple air outlets 222a to the rotational center axis L1. That is, the average value calculated by comprehensively calculating the distances from each point on each air outlet 222a to the rotational center axis L1 increases sequentially. When the crossflow impeller 20 is in operation, due to the sequentially increasing average projected distances from the multiple air outlets 222a to the rotational center axis L1, the airflow passing through the blades 222 is subjected to varying degrees of centrifugal force. Air outlets 222a closer to the rotational center axis L1 experience relatively less centrifugal force. However, as the average projected distance increases, the centrifugal force on the airflow corresponding to the air outlet 222a gradually increases. This causes differential changes in the flow speed and direction of the airflow on the surface of the blade 222 , thereby changing the angle and speed distribution of the airflow when it flows out of the blade 222 .

[0098] In terms of airflow efficiency, this differentiated airflow output creates a more complex and diverse airflow combination at the air outlet 10b. On the one hand, it expands the airflow coverage, allowing a wider area of ​​the indoor space to be covered by the airflow, avoiding dead spots and optimizing indoor air uniformity. On the other hand, the interweaving of airflows at different speeds and angles helps enhance the airflow's diffusion capacity within the room, improving air circulation efficiency and thus enhancing the indoor unit's air conditioning capabilities, creating a more comfortable indoor air environment for the user.

[0099] Referring to Figures 7 and 16 , in another embodiment, when viewed along the axial direction L2 perpendicular to the crossflow impeller 20, the projected distances from the multiple outlets 222a of each blade 222 in each group to the rotational axis L1 decrease sequentially. Thus, when the crossflow impeller 20 is in operation, because the average projected distances from the multiple outlets 222a to the rotational axis L1 decrease sequentially, the centrifugal force experienced by the airflow through the blades 222 changes in a trend opposite to that observed when the average projected distance increases. Airflow initially experiences greater centrifugal force at outlets 222a farther from the rotational axis L1, but this force decreases as the average projected distance decreases. This change in centrifugal force alters the flow pattern of the airflow on the surface of the blades 222, resulting in differential adjustments in its velocity and direction, resulting in a unique pattern in the angular and velocity distribution of the airflow exiting the blades 222.

[0100] From the perspective of air delivery effectiveness, this differentiated airflow output pattern creates a unique airflow pattern at the air outlet 10b. Unlike a scenario where the average projected distance increases sequentially, this design tends to concentrate airflow toward a specific area, significantly increasing the air delivery distance. This allows the indoor unit 100 to deliver airflow to locations farther away, effectively achieving long-range air delivery and conditioning in larger spaces such as shopping malls and large conference rooms. Furthermore, due to the relatively concentrated airflow, the airflow intensity in a specific direction is enhanced, which is crucial for targeted improvements in localized air quality. For example, in areas with high requirements for local environmental parameters such as temperature and humidity, these requirements can be more precisely met. Furthermore, by cleverly utilizing the airflow variations brought about by the sequential decrease in average projected distance, the indoor unit 100 delivers airflow more efficiently. While meeting the specific air delivery distance and localized air conditioning requirements, it also reduces unnecessary energy loss and optimizes energy utilization. Compared with the traditional air supply structure, energy consumption can be reduced while achieving the same air supply effect. This not only conforms to the current society's advocacy of energy conservation and environmental protection, but also saves users operating costs during long-term use.

[0101] Furthermore, when observed along the axial direction L2 perpendicular to the cross-flow impeller 20, the projection distance changes of the multiple air outlets 222a in each blade 222 in each group to the rotation center axis L1 can be the same, for example, increasing or decreasing in sequence. Whether increasing or decreasing in sequence, it brings unique optimization to the air supply effect of the indoor unit 100. When the projection distance increases in sequence, it focuses on expanding the air supply width and improving air uniformity; when the projection distance decreases in sequence, it focuses on increasing the air supply distance and directionally improving the local environment. These two design methods provide a variety of options to adapt to different indoor space environments and user needs, help to improve the overall performance and applicability of the indoor unit 100, and better meet people's pursuit of a comfortable indoor air environment.

[0102] 5 , 15 and 16 , in some other embodiments, when observed along the axial direction L2 perpendicular to the cross-flow blower 20, for two adjacent cross-flow blowers 20, the projected distances from the multiple air outlets 222a in each blade 222 in each group of one cross-flow blower 20 to the rotation center axis L1 increase sequentially, while the projected distances from the multiple air outlets 222a in each blade 222 in each group of the other cross-flow blower 20 to the rotation center axis L1 decrease sequentially.

[0103] The projected distances referred to herein are all average distances, calculated from the distances from each point on each air outlet 222a to the center axis of rotation L1. When the indoor unit 100 is operating, the airflow passing through two adjacent crossflow impellers 20 exhibits distinct flow characteristics due to the different trends in the projected distances of the air outlet 222a. For crossflow impellers 20 with successively larger projected distances from the air outlet 222a, the airflow is affected by centrifugal force, and as it moves from closer to the center axis of rotation L1 to farther away from it, the velocity and direction of the airflow gradually change, resulting in a more dispersed angle and velocity distribution of the outflowing airflow. This helps expand the breadth of air supply, allowing a wider area of ​​the room to be covered by the airflow, effectively avoiding dead spots in air supply and promoting uniform mixing of indoor air. For the crossflow impeller 20, whose projected distance of the air outlet 222a decreases sequentially, the centrifugal force experienced by the airflow gradually decreases as it moves from farther away from the rotation axis L1 to closer to it, resulting in a more concentrated airflow upon exit. This significantly increases the air delivery distance and is particularly suitable for delivering air to distant locations within large spaces. When these two crossflow impellers 20 with different characteristics work together, a highly complex and complementary airflow combination is formed at the air outlet 10b. This not only balances air delivery width and distance, meeting the air conditioning needs of different spatial areas, such as a spacious living room, allowing for comfortable airflow in corners while achieving effective ventilation within a long, narrow space. Furthermore, the interaction of airflows further enhances indoor air circulation efficiency. The collision and interweaving of airflows of varying speeds and directions accelerates air mixing and exchange, ensuring more uniform and stable indoor environmental parameters such as temperature and humidity, significantly improving human comfort. From an energy-saving perspective, this design optimizes airflow delivery and precisely allocates energy according to the needs of different spaces. While meeting the requirements of complex space air conditioning, it avoids unnecessary energy waste and improves energy efficiency. Compared with traditional single-mode air supply systems, while achieving the same comfortable environment, it can reduce energy consumption, saving users long-term operating costs. At the same time, it also responds to the social development trend of energy conservation and environmental protection, with significant economic and environmental benefits.

[0104] Referring to Figure 14, in some embodiments, the volute 11 includes a volute body 111 and a guide rib 112. The guide rib 112 is protruded from the volute body 111. The guide rib 112 and the volute body 111 can be integrally formed components. This not only enhances the strength of the connection between the guide rib 112 and the volute body 111, but also reduces the number of assembly steps for the guide rib 112 and the volute body 111. Of course, the guide rib 112 and the volute body 111 can also be separate components, which is not limited in this embodiment. There are multiple guide ribs 112, and the multiple guide ribs 112 are protruded from the volute body 111 at intervals. A guide groove 113 is defined between two adjacent guide ribs 112. It can be understood that the airflow delivered by the crossflow impeller 20 can flow smoothly to the air outlet under the guidance of the guide ribs 112 and the guide groove 113.

[0105] Among them, when the cross-flow impeller 20 rotates to any angle, along the air outlet direction of the cross-flow impeller 20, the air outlet portion 222a of the blade 222 whose air outlet tail end 2221 is opposite to the guide rib 112 is opposite to the guide groove 113, and the air supply cutout 222b of the blade 222 is opposite to the guide rib 112.

[0106] It is understood that the large vortex in the wake of the airflow discharged from the area of ​​the air outlet tail end 2221 having the air supply cutout 222b is prematurely transformed into multiple small vortices. However, the airflow discharged from the area of ​​the air outlet tail end 2221 not having the air supply cutout 222b, i.e., the airflow discharged from the air outlet portion 222a, requires a longer time to transition from a laminar flow state to a turbulent flow state. Therefore, while the relative distance between the volute tongue 11 and the crossflow impeller 20 cannot be increased due to the fixed size of the indoor unit 100, the guide groove 113 is aligned with the air outlet portion 222a, which appropriately extends the distance that the airflow discharged from the air outlet portion 222a travels to the volute tongue 11. This allows the large vortex in the wake of the airflow discharged from the air outlet portion 222a to be prematurely transformed into multiple small vortices before the airflow strikes the bottom wall of the guide groove 113, thereby further reducing noise intensity. Thus, in this embodiment, the combination of the form in which the endpoint line L1L1 is inclined relative to the axial direction L2 of the cross-flow impeller 20 and the form in which the air supply cutout 222b is provided on the air outlet tail end 2221 can achieve a combined noise reduction effect, and more effectively reduce the intensity of the noise generated by the indoor unit 100 during operation.

[0107] Furthermore, the air-supply slits 222b of different blades 222 of the same cross-flow wind wheel 20 are arranged in a circle along the circumference of the cross-flow wind wheel 20, that is, the air-supply slits 222b of different blades 222 are relatively arranged along the circumference of the cross-flow wind wheel 20, and multiple circles of air-supply slits 222b are arranged along the axial direction L2 of the cross-flow wind wheel 20.

[0108] On the one hand, from the perspective of noise reduction, if the air-supply slits 222b of different blades 222 are arranged non-oppositely along the circumference of the crossflow rotor 20, for example, if the air-supply slit 222b of one of two adjacent blades 222 is opposite the air outlet 222a of the other blade 222 along the circumference of the crossflow rotor 20, the phase difference in the impact of the crossflow rotor 20 on the volute tongue 11 will be small during rapid rotation, and there is still a low possibility of resonance. Based on this, by arranging the air-supply slits 222b of different blades 222 in a circle along the circumference of the crossflow rotor 20, the phase difference in the impact of the crossflow rotor 20 on the volute tongue 11 during rapid rotation can be large, further reducing the possibility of resonance and more effectively reducing the intensity of noise.

[0109] On the other hand, from the perspective of production and manufacturing, when the blade 222 is made of plastic and is injection molded, a plurality of spaced convex ribs can be provided in the mold cavity of the mold used to produce the blade 222, and each convex rib can be configured to be annular. In this way, the molding of each circle of air-supply cutouts 222b of the multiple blades 222 is achieved through the multiple convex ribs. When the multiple air-supply cutouts 222b belonging to the same circle are relative to each other in the circumferential direction, the corresponding convex ribs are continuous and uninterrupted ribs as a whole, thereby making the structural design of the mold simpler, reducing the production cost of the mold, and making it easier to demold and facilitate injection molding production.

[0110] Optionally, the cross-section of each air-supplying slit 222b parallel to the length direction of the blade 222 is rectangular, triangular or trapezoidal, so that the shape is more regular and the air-supplying slit 222b is easier to process.

[0111] Referring to FIG. 8 , in some embodiments, an offset angle A is formed between the adjacent blades 222 of two adjacent groups of blades 222 and the axis of the crossflow impeller 20 in their extension direction, and A is less than or equal to 8 degrees and greater than or equal to 5 degrees. Thus, by forming the offset angle A, the airflow from the two adjacent impeller sections 22 is staggered, so that the airflows delivered by the blades 222 of the two adjacent impeller sections 22 impact the volute tongue 11 at different times. When passing through the volute tongue 11, the impact phases on the volute tongue 11 differ, resulting in a discrete frequency spectrum, making resonance less likely and effectively reducing noise intensity. Moreover, in this embodiment, the combination of the form in which the end point line L1L1 is inclined relative to the axial direction L2 of the cross-flow impeller 20, the form in which an air supply cutout 222b is provided on the air outlet tail end 222111, and the form in which the air outlet portion 222a is opposite to the guide groove 113 and the air supply cutout 222b is opposite to the guide rib 112, can achieve a combined noise reduction effect, and more effectively reduce the intensity of the noise generated by the indoor unit 100 during operation.

[0112] Optionally, in the radial direction of the crossflow impeller 20, each blade 222 does not extend beyond the outer edge of the fixed wall 221. This prevents the outlet ends 2221 of the blades 222 from extending beyond the outer edge of the fixed wall 221, thereby reducing the possibility of injuries to workers caused by touching the outlet ends 2221.

[0113] Optionally, the number of blades 222 on two adjacent crossflow impellers 20 differs. This ensures that the airflow driven by the two adjacent crossflow impellers 20 reaches the volute 11 at different times, thereby staggering the resonant frequencies and effectively reducing noise intensity. The number of blades 222 on the crossflow impeller 20 is 35 to 37. This further facilitates the air intake and sweeping of the blades 222, allowing the crossflow impeller 20 to generate a greater air volume. This reduces the load on the drive motor 50 while maintaining a constant air volume, thereby reducing noise from the indoor unit 100.

[0114] The above is an explanation of the specific structural example of the indoor unit of the embodiment of the present application. It can be understood that since the HVAC system of the present application adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here one by one.

[0115] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of this application, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate an orientation or position relationship, 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 operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0116] 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: include: A housing having an air inlet and an air outlet spaced apart on a bottom surface thereof, and an air duct communicating with the air inlet and the air outlet formed inside the housing; and At least two cross-flow impellers, the at least two cross-flow impellers being disposed in the air duct and spaced apart in a longitudinal extension direction of the air outlet; The crossflow wind wheel includes multiple groups of blades, each group of blades has multiple blades, and the multiple blades in a group are arranged at intervals along the circumference of the rotation center axis of the crossflow wind wheel. When observed along the axial direction perpendicular to the crossflow wind wheel, each blade in a group of blades is inclined relative to the axial direction.

2. The indoor unit according to claim 1, wherein: The blades of two adjacent crossflow impellers have the same inclination direction.

3. The indoor unit according to claim 1, wherein: The blades of two adjacent crossflow impellers have different inclination directions.

4. The indoor unit according to claim 1, wherein: Each of the cross-flow wind wheels has a plurality of fixed walls spaced apart along the axial direction, a group of blades is provided between each two adjacent fixed walls, each blade has an air outlet tail end away from the central axis of rotation of the cross-flow wind wheel, the air outlet tail end includes a plurality of air outlet portions spaced apart, and an air supply incision is defined between two adjacent air outlet portions.

5. The indoor unit according to claim 4, wherein: When viewed along an axial direction perpendicular to the crossflow impeller, the projected distances from the plurality of air outlet portions of each blade in each group to the rotation center axis increase sequentially.

6. The indoor unit according to claim 4, wherein: When viewed along an axial direction perpendicular to the crossflow impeller, the projected distances from the plurality of air outlet portions of each blade in each group to the rotation center axis decrease in sequence.

7. The indoor unit according to claim 4, wherein: The air-supply slits of different blades of the same crossflow impeller are arranged in a circle along the circumference of the crossflow impeller, and multiple circles of the air-supply slits are arranged along the axial direction of the crossflow impeller; And / or, the cross-section of each of the air-replenishing incisions parallel to the length direction of the blade is rectangular, triangular or trapezoidal.

8. The indoor unit according to claim 1, wherein: On two adjacent groups of blades, there is a misalignment angle A between the two adjacent blades and the axis of the crossflow impeller in their extension directions, and A is less than or equal to 8 degrees and greater than or equal to 5 degrees.

9. The indoor unit according to any one of claims 1 to 8, wherein: The numbers of blades of two adjacent crossflow impellers are different.

10. The indoor unit according to any one of claims 1 to 8, wherein: The indoor unit further includes a heat exchanger, which is arranged in the air duct and located between the crossflow impeller and the air inlet.

11. The indoor unit according to claim 10, wherein: The housing includes a casing, a panel, and a water receiving tray. The bottom of the casing is open, and the panel cover is provided at the open position. The air inlet and the air outlet are arranged on the panel at intervals. The heat exchanger, the crossflow impeller, and the water receiving tray are all provided in the casing. The casing, the panel, and the water receiving tray cooperate to form the air duct. The water receiving tray is located below the wind wheel and the heat exchanger to collect condensed water generated by the heat exchanger.

12. A heating and ventilation system, wherein: The invention comprises an outdoor unit and an indoor unit according to any one of claims 1 to 13, wherein the outdoor unit is connected to the indoor unit.

13. An indoor unit, wherein: include: A housing having an air inlet and an air outlet spaced apart on a bottom surface thereof, and an air duct communicating with the air inlet and the air outlet formed inside the housing; and At least two cross-flow impellers, the at least two cross-flow impellers being disposed in the air duct and spaced apart in a longitudinal extension direction of the air outlet; The crossflow rotor includes a plurality of blades, each of which has a plurality of blades, and the plurality of blades in a group are arranged at intervals along the circumference of the rotation center axis of the crossflow rotor; Each of the blades has an air outlet tail end away from the rotation center axis of the crossflow impeller, the air outlet tail end includes a plurality of air outlet portions arranged in sequence and spaced apart, and an air supply notch is defined between two adjacent air outlet portions; When observed along the axial direction perpendicular to the crossflow impeller, the projected distances from the multiple air outlet portions of each blade in each group to the rotation center axis increase or decrease in sequence.

14. The indoor unit according to claim 13, wherein: The air-supply slits of different blades of the same crossflow impeller are arranged in a circle along the circumference of the crossflow impeller, and multiple circles of the air-supply slits are arranged along the axial direction of the crossflow impeller; And / or, the cross-section of each of the air-replenishing incisions parallel to the length direction of the blade is rectangular, triangular or trapezoidal.

15. The indoor unit according to claim 13, wherein On two adjacent groups of blades, there is an offset angle A between the two adjacent blades in their extension directions and the axis of the crossflow impeller, and A is less than or equal to 8 degrees and greater than or equal to 5 degrees; And / or, the number of blades of two adjacent crossflow wind wheels is different.

16. The indoor unit according to claim 13, wherein: The indoor unit further includes a heat exchanger, which is arranged in the air duct and located between the crossflow impeller and the air inlet.

17. The indoor unit according to claim 16, wherein: The housing includes a casing, a panel, and a water receiving tray. The bottom of the casing is open, and the panel cover is provided at the open position. The air inlet and the air outlet are arranged on the panel at intervals. The heat exchanger, the crossflow impeller, and the water receiving tray are all provided in the casing. The casing, the panel, and the water receiving tray cooperate to form the air duct. The water receiving tray is located below the wind wheel and the heat exchanger to collect condensed water generated by the heat exchanger.

18. An indoor unit, wherein: include: A housing having an air inlet and an air outlet spaced apart on a bottom surface thereof, and an air duct communicating with the air inlet and the air outlet formed inside the housing; and At least two cross-flow impellers, the at least two cross-flow impellers being disposed in the air duct and spaced apart in a longitudinal extension direction of the air outlet; The crossflow rotor includes a plurality of blades, each of which has a plurality of blades, and the plurality of blades in a group are arranged at intervals along the circumference of the rotation center axis of the crossflow rotor; Each of the blades has an air outlet tail end away from the rotation center axis of the crossflow impeller, the air outlet tail end includes a plurality of air outlet portions arranged in sequence and spaced apart, and an air supply notch is defined between two adjacent air outlet portions; When observed along the axial direction perpendicular to the cross-flow wind wheel, of two adjacent cross-flow wind wheels, the projected distances from the multiple air outlets in each blade in each group of one cross-flow wind wheel to the rotation center axis increase sequentially, while the projected distances from the multiple air outlets in each blade in each group of the other cross-flow wind wheel to the rotation center axis decrease sequentially.

19. The indoor unit according to claim 18, wherein The air-supply slits of different blades of the same crossflow impeller are arranged in a circle along the circumference of the crossflow impeller, and multiple circles of the air-supply slits are arranged along the axial direction of the crossflow impeller; And / or, the cross-section of each of the air-replenishing incisions parallel to the length direction of the blade is rectangular, triangular or trapezoidal.

20. The indoor unit according to claim 18, wherein On two adjacent groups of blades, there is an offset angle A between the two adjacent blades in their extension directions and the axis of the crossflow impeller, and A is less than or equal to 8 degrees and greater than or equal to 5 degrees; And / or, the number of blades of two adjacent crossflow wind wheels is different.

21. The indoor unit according to claim 18, wherein The indoor unit further includes a heat exchanger, which is arranged in the air duct and located between the crossflow impeller and the air inlet.

22. The indoor unit according to claim 21, wherein The housing includes a casing, a panel, and a water receiving tray. The bottom of the casing is open, and the panel cover is provided at the open position. The air inlet and the air outlet are arranged on the panel at intervals. The heat exchanger, the crossflow impeller, and the water receiving tray are all provided in the casing. The casing, the panel, and the water receiving tray cooperate to form the air duct. The water receiving tray is located below the wind wheel and the heat exchanger to collect condensed water generated by the heat exchanger.

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