Indoor unit of air conditioner

Abstract

The utility model discloses an air conditioner indoor unit, and belongs to the technical field of air treatment. The air conditioner indoor unit comprises a fan assembly. The fan assembly comprises a centrifugal fan with an impeller and a volute; the volute comprises a volute body provided with a fan air inlet, and the fan air inlet is opposite to the impeller in the axial direction of the impeller. The fan air outlet channel is connected with the volute body and used for allowing air to flow out of the volute; the fan air outlet channel comprises a connecting section connected with the volute body; the involute section is connected to the end, away from the volute body, of the connecting section; side plates on the two sides of the involute section are first flow guide plates, and the two first flow guide plates are sequentially arranged in the direction parallel to the axis of the impeller; the first flow guide plates are arc-shaped, and the distance between the two first flow guide plates is gradually increased in the direction away from the volute body. The air outlet amount can be increased, backflow airflow is inhibited from forming vortexes on the inner side of the fan air outlet channel, and noise is reduced.

Description

Technical Field

[0001] This utility model relates to the field of air conditioning technology, and in particular to an indoor unit for air conditioning. Background Technology

[0002] As a core component of an air conditioning system, the indoor unit plays a crucial role in regulating indoor temperature and air quality. It primarily achieves heat transfer through refrigerant circulation and fan operation, thus providing cooling or heating. Within the indoor unit, the indoor fan is the key component for air circulation; it draws in indoor air, facilitates heat exchange through the evaporator or condenser, and then blows it out to regulate indoor temperature. However, with increasing demands for comfort and energy efficiency, higher requirements are being placed on the performance of indoor air conditioning units, particularly regarding fan airflow and noise control.

[0003] In existing technology, the fan assembly of an air conditioner indoor unit typically uses a centrifugal fan, which mainly consists of an impeller and a volute. Driven by a motor, the impeller rotates, drawing in and accelerating air, which is then directed to the outlet through the volute. However, this traditional centrifugal fan design has several problems. First, the outlet of the volute is usually a flat-mouth structure. When airflow exits from the impeller, vortices and separation are easily generated at the edge of the outlet, leading to localized pressure loss and reducing the overall efficiency of the fan. Second, this design generates significant noise when airflow passes through, affecting the user experience. Furthermore, the instability of the airflow at the outlet can also lead to airflow diffusion and energy loss, further impacting the cooling and heating performance of the air conditioner indoor unit. Utility Model Content

[0004] This utility model aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, according to embodiments of this disclosure, an air conditioning indoor unit is proposed, including a housing; a fan assembly disposed within the housing for driving airflow; the fan assembly includes a centrifugal fan.

[0006] A centrifugal fan includes an impeller and a volute casing covering the impeller. The volute casing includes: a volute casing body with a fan inlet for air to enter the volute casing, the fan inlet being axially opposite to the impeller; and a fan outlet passage connected to the volute casing body for air to exit the volute casing.

[0007] The fan outlet duct includes: a connecting section, which is connected to the volute body; and an involute section, which is connected to the end of the connecting section away from the volute body. The side plates on both sides of the involute section are first guide plates. The two first guide plates are arranged sequentially in a direction parallel to the impeller axis. The first guide plates are arc-shaped, and the distance between the two first guide plates gradually increases in the direction away from the volute body.

[0008] In this technical solution, a gradually expanding first guide vane is installed on the fan's outlet duct, creating a gradually widening outlet that increases the airflow distribution width in the outlet direction, thereby increasing the airflow volume without increasing the motor speed. Furthermore, the gradually widening flow channel conforms to the airflow's trajectory after leaving the impeller, ensuring that the airflow continues to flow away from the fan components after exiting the outlet duct, reducing the amount of spiral backflow towards the fan components, thus suppressing eddies and reducing noise.

[0009] In some embodiments, the fan inlet includes a first fan inlet and a second fan inlet disposed opposite to each other; the two first guide vanes are a first side guide vane and a second side guide vane, respectively; the first side guide vane and the first fan inlet are located on one side of the volute axial direction, and the second side guide vane and the second fan inlet are located on the other side of the volute axial direction.

[0010] The end of the fan outlet passage away from the volute body forms the fan outlet; on the cross section of the fan outlet passage that is perpendicular to the fan outlet and parallel to the axis of the impeller, the midpoint of the outline of the second fan inlet is located on the circle containing the inner side of the first side guide plate, and the midpoint of the outline of the first fan inlet is located on the circle containing the inner side of the second side guide plate.

[0011] In the technical solution, the structural design enables the arc-shaped opening structure to guide the airflow of the surrounding area, allowing the airflow to gather on the arc-shaped trajectory formed by the arc-shaped opening structure, reducing the influence of airflow blown out by other fans, reducing airflow loss and vortex generation, thereby reducing noise.

[0012] In some embodiments, the diameter of the circle containing the inner side of the first guide plate is D, and the length of the volute body in the impeller axial direction is W0, where 1.4W0≤D≤1.5W0.

[0013] In the technical solution, the structural design avoids the airflow from spreading outwards due to excessive expansion of the flow channel after leaving the impeller. It maintains the tendency of the airflow to flow away from the fan components, making the airflow blown out of the indoor unit of the air conditioner more concentrated and regulating the temperature in the indoor area more quickly.

[0014] In some embodiments, the two first deflectors are arranged symmetrically.

[0015] In the technical solution, the symmetrically arranged first guide vane can make the airflow evenly distributed on both sides of the fan outlet channel, avoiding airflow deflection or local vortex phenomenon caused by the asymmetry of the guide vane, thereby further improving the stability of the airflow and the air outlet efficiency, while reducing the noise caused by uneven airflow.

[0016] In some embodiments, the maximum distance between the two first guide vanes is W1, and the length of the volute body in the impeller axial direction is W0, where 1.02W0≤W1≤1.06W0.

[0017] In the technical solution, the structural design provides a longer involute space for the airflow, ensuring that the airflow leaving the impeller and blowing the fan outlet channel at various positions along the impeller axis can maintain a flow away from the fan components, thereby further reducing airflow backflow and eddy currents and improving airflow efficiency.

[0018] In some embodiments, the maximum distance between the two first guide vanes is W1, and the length of the volute body in the impeller axial direction is W0, where W1 = 1.04W0.

[0019] In the technical solution, the structural design ensures that the airflow has a longer involute space, ensuring that the airflow leaving the impeller and blowing the fan outlet at various positions along the impeller axis can maintain a flow away from the fan components, thereby further reducing airflow backflow and eddy currents and improving airflow efficiency.

[0020] In some embodiments, the connecting section includes a volute tongue, the inner wall surface of which has an arc surface; the involute section is located on the air outlet side of the arc surface.

[0021] In this technical solution, the involute section and the volute tongue are separated to avoid the influence of the involute section on the airflow of the volute tongue section.

[0022] In some embodiments, the end of the fan outlet channel away from the volute body forms the fan outlet; in the direction perpendicular to the fan outlet, the distance from the fan outlet to the arc surface is L1, the length of the involute is L, and L≥0.6L1.

[0023] In this technical solution, the length of the involute section can be ensured to be long enough to achieve its functions of guiding airflow, increasing air volume, and suppressing eddies.

[0024] In some embodiments, the fan outlet duct includes a second guide plate connected to the two first guide plates.

[0025] In some embodiments, a backflow preventer is provided on the outer surface of the fan outlet duct.

[0026] In this technical solution, the structural design can more comprehensively suppress the occurrence of airflow backflow, further enhance the ability to guide and control airflow, reduce the airflow velocity of the backflow along the wall towards the fan inlet, avoid the local negative pressure generated by the high-speed backflow airflow attracting more backflow of the airflow flowing out of the fan outlet channel, improve the operating efficiency and stability of the air conditioner, and at the same time reduce the noise generated by airflow backflow and eddies, thus improving the user experience.

[0027] In some embodiments, the fan assembly includes a plurality of centrifugal fans arranged along the axis of the impeller.

[0028] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a perspective view of the concealed portion of the housing of the indoor unit of an air conditioner according to an embodiment of this application;

[0031] Figure 2 This is a cross-sectional view of an indoor air conditioning unit according to an embodiment of this application;

[0032] Figure 3 This is a perspective view of the centrifugal fan of an indoor air conditioning unit according to an embodiment of this application;

[0033] Figure 4 This is a side view of the centrifugal fan of an indoor air conditioning unit according to an embodiment of this application;

[0034] Figure 5 This is a cross-sectional view of the centrifugal fan of an air conditioner indoor unit according to an embodiment of this application. Figure 1 ;

[0035] Figure 6 This is a cross-sectional view of the centrifugal fan of an air conditioner indoor unit according to an embodiment of this application. Figure 2 ;

[0036] Figure 7 This is an airflow distribution diagram of a centrifugal fan in the prior art;

[0037] Figure 8 This is an airflow distribution diagram of the centrifugal fan of an air conditioner indoor unit according to an embodiment of this application.

[0038] In the above figures:

[0039] 100. Indoor unit of air conditioner; 1. Casing; 11. Indoor air inlet; 12. Indoor air outlet; 13. Middle partition; 2. Heat exchanger; 3. Fan assembly; 31. Volute; 311. Volute body; 312. Fan air inlet; 3121. First fan air inlet; 3122. Second fan air inlet; 313. Fan air outlet duct; 3130. Fan air outlet; 3131. Connecting section; 3132. Involute section; 3133. First guide vane; 3134. First side guide vane; 3135. Second side guide vane; 3136. Second guide vane; 3137. Volute tongue; 3138. Curved surface; 314. Anti-reverse baffle; 32. Impeller; 321. Hub; 322. Blade; 33. Motor. Detailed Implementation

[0040] The present invention will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0041] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0042] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0043] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0044] Air conditioners execute a refrigeration cycle using a compressor, condenser, expansion valve, and evaporator. The refrigeration cycle involves a series of processes including compression, condensation, expansion, and evaporation, supplying refrigerant to the conditioned and heat-exchanged air.

[0045] The compressor compresses refrigerant gas at a low temperature and low pressure and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process.

[0046] The expansion valve expands the high-temperature, high-pressure liquid refrigerant condensed in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the expanded refrigerant in the expansion valve, returning the low-temperature, low-pressure refrigerant gas to the compressor. The evaporator achieves its cooling effect by utilizing the latent heat of refrigerant evaporation to exchange heat with the material being cooled. Throughout the cycle, the air conditioner regulates the temperature of the indoor space.

[0047] The outdoor unit of an air conditioner refers to the part of the refrigeration cycle that includes the compressor and the outdoor heat exchanger. The indoor unit of an air conditioner includes the indoor heat exchanger, and an expansion valve can be provided in either the indoor or outdoor unit.

[0048] The indoor and outdoor heat exchangers function as either condensers or evaporators. When the indoor heat exchanger is used as a condenser, the air conditioner functions as a heater in heating mode; when the indoor heat exchanger is used as an evaporator, the air conditioner functions as a cooler in cooling mode.

[0049] When the indoor and outdoor units of an air conditioner are separate units, the indoor unit is also called the indoor air conditioner unit, and the outdoor unit is also called the outdoor air conditioner unit.

[0050] The embodiments of this application are described below with reference to the accompanying drawings:

[0051] refer to Figure 1 and Figure 2 According to the embodiments of this application, the indoor unit of the air conditioner includes a housing 1, in which a plurality of components constituting a refrigeration cycle are installed.

[0052] The housing 1 can generally be in the shape of a cuboid, including a bottom surface defining a bottom structure, a top surface defining a top structure, and a side surface disposed between the top surface and the bottom surface.

[0053] The housing 1 includes an indoor air inlet 11 through which indoor air is introduced. The indoor air inlet 11 can be formed by opening a portion of the bottom of the housing 1; or by opening one side of the housing 1.

[0054] The casing 1 includes an indoor air outlet 12, through which air introduced through the indoor air inlet 11 undergoes heat exchange, and then is discharged into the indoor space through the indoor air outlet 12.

[0055] An indoor air outlet 12 can be formed by opening at least a portion of the side of the housing 1. A duct can be connected to the indoor air outlet 12, with one end of the duct extending into the indoor space away from the indoor air outlet 12. An air outlet flange for connecting to the duct can be provided at the indoor air outlet 12.

[0056] The indoor unit of the air conditioner may include a heat exchanger 2. The heat exchanger 2 is installed inside the casing 1 and exchanges heat with the air drawn in through the indoor air inlet 11.

[0057] The heat exchanger 2 may include refrigerant pipes through which refrigerant flows and heat exchange fins connected to the refrigerant pipes to increase the heat exchange area. The heat exchanger 2 may be located on the air outlet side of the fan assembly 3, that is, the heat exchanger 2 may be located near the indoor air outlet 12.

[0058] The indoor unit of the air conditioner may include a fan assembly 3, which is located inside the casing 1 and is used to provide power for the flow of air.

[0059] A partition 13 may be provided inside the casing 1. The partition 13 divides the internal space of the casing 1 into an air inlet chamber and an air outlet chamber, with the indoor air inlet 11 located on the air inlet chamber side and the indoor air outlet 12 located on the air outlet chamber side. The fan assembly 3 is located in the air inlet chamber, and the heat exchanger 2 is located in the air outlet chamber.

[0060] The fan outlet 3130 of the fan assembly 3 faces the air outlet cavity, which can blow air towards the heat exchanger 2. Under the action of the fan assembly 3, the air enters the air inlet cavity from the indoor air inlet 11, and then flows through the fan assembly 3 to the heat exchanger 2 in the air outlet cavity. After exchanging heat with the heat exchanger 2, the air is blown out from the indoor air outlet 12.

[0061] refer to Figures 3 to 6 The fan assembly 3 includes a centrifugal fan.

[0062] The centrifugal fan includes a volute 31. The volute 31 is the outer casing structure of the centrifugal fan. The inner wall of the volute 31 is typically a smooth, streamlined surface to reduce airflow resistance and energy loss.

[0063] The volute 31 is connected to the housing 1. The volute 31 can be connected to the top wall of the housing 1 by fasteners such as screws.

[0064] The volute 31 includes a volute body 311, on which a fan inlet 312 is provided. The fan inlet 312 connects the internal space of the volute 31 with the space outside the volute 31, allowing air to enter the volute 31. The fan inlet 312 is located at one end of the volute body 311, or fan inlets 312 are provided at both ends of the volute body 311.

[0065] The volute body 311 is generally cylindrical, and the fan inlet 312 can be located at the end of the volute body 311 that is perpendicular to its axis.

[0066] The volute 31 may include a fan outlet duct 313. The fan outlet duct 313 is a channel structure connected to the volute body 311, used to connect the internal space of the volute body 311 with the space outside the volute body 311, allowing air to flow out of the volute 31. The fan outlet duct 313 may extend into the air outlet cavity through a partition plate 13, so that the fan outlet duct 313 is connected to the air outlet cavity.

[0067] The fan assembly 3 includes an impeller 32. The impeller 32 is located inside the volute 31, and the volute 31 covers the impeller 32. Specifically, the impeller 32 is located inside the volute body.

[0068] For details, please refer to the following: Figure 6 The impeller 32 includes a hub 321. The hub 321 is annular and passes through the drive shaft of the motor 33.

[0069] The impeller 32 includes blades 322, which are connected to the outer periphery of the hub 321. Multiple blades 322 are arranged at intervals along the circumference of the hub 321, and the length direction of the blades 322 is parallel to the axis of the impeller 32.

[0070] The fan inlet 312 is positioned axially opposite to the impeller 32, thus located on the outer side of one end of the impeller 32.

[0071] The fan assembly 3 may include a motor 33, which may be connected to the housing 1 or to the partition plate 13. The drive shaft of the motor 33 is connected to the impeller 32. Driven by the motor 33, the impeller 32 rotates in the volute 31, causing the air in the air inlet chamber to enter the volute 31 through the fan inlet 312 and then be blown out through the fan outlet 313 after passing through the impeller 32.

[0072] In some embodiments, the fan assembly 3 includes a plurality of centrifugal fans arranged at axial intervals along the impeller 32. The plurality of centrifugal fans cause multiple airflows to be blown simultaneously toward the outlet side.

[0073] In some embodiments, reference Figure 3 , Figure 5 and Figure 6 The fan outlet duct 313 includes a connecting section 3131. One end of the connecting section 3131 is fixedly connected to the volute body 311.

[0074] The fan outlet duct 313 may include an involute section 3132. One end of the involute section 3132 is connected to the end of the connecting section 3131 away from the volute body 311, thereby connecting and fixing the involute section 3132 and the connecting section 3131.

[0075] refer to Figure 3 and Figure 4The side plates on both sides of the involute section 3132 are the first guide plates 3133. The two first guide plates 3133 are arranged sequentially along a direction parallel to the axis of the impeller 32.

[0076] Along the direction of airflow, the distance between the two first guide plates 3133 gradually increases, which makes the space between the two first guide plates 3133 gradually increase in the direction of airflow. The section of the fan outlet channel 313 away from the volute body 311 is gradually widened, which increases the distribution width of the airflow in the outlet direction, thereby increasing the airflow volume without increasing the speed of the motor 33.

[0077] In the prior art, see Figure 7 The centrifugal fan's volute uses a flat-mouth outlet duct (flat-mouth means the distance between the two first guide vanes is constant). This results in a narrow airflow distribution width and a smaller air volume. Therefore, it's necessary to increase the motor speed in the fan assembly to raise the impeller speed and increase the airflow, which leads to increased noise from the motor and impeller rotation. Furthermore, at the edge of the fan outlet, the sudden change in airflow geometry causes localized pressure loss, making airflow separation more likely. This creates low-pressure areas and vortices within the airflow, further exacerbating noise problems. The pressure loss also reduces the overall fan efficiency, affecting the performance of the entire ventilation system.

[0078] Reference Figure 8 In this application, the gradually opening flow channel formed between the two first guide plates 3133 conforms to the changing trend of the airflow after leaving the impeller 32. This causes the space in which the airflow is located to gradually expand as it leaves the fan outlet channel 313, reducing the pressure loss of the airflow. This ensures that the airflow continues to flow away from the fan assembly 3 after leaving the fan outlet channel 313, reducing airflow separation and thus reducing the eddies generated by the airflow. This results in less spiral backflow of airflow towards the fan assembly 3, further ensuring that the airflow continues to flow away from the fan assembly 3. In addition, the first guide plates 3133 guide the airflow that flows back towards the fan assembly 3 from the outside of the fan outlet channel 313, causing more of this airflow to flow from the outside of the fan outlet channel 313 towards the fan inlet 312. This suppresses the formation of eddies by the backflowing airflow inside the fan outlet channel 313, reducing noise.

[0079] In some embodiments, the first guide plate 3133 is an arc shape that bulges outward, so that the internal space of the involute section 3132 gradually increases in the direction away from the volute body 311.

[0080] The two arc-shaped first guide plates 3133 gradually increase the internal space of the fan outlet channel 313 away from the volute body 311.

[0081] In some embodiments, reference Figure 6 The fan inlet 312 includes a first fan inlet 3121 and a second fan inlet 3122 arranged opposite to each other, such that the first fan inlet 3121 and the second fan inlet 3122 are located at opposite ends of the volute body 311. Two first guide plates 3133 are a first side guide plate 3134 and a second side guide plate 3135. The first side guide plate 3134 and the first fan inlet 3121 are located on the same side of the volute axial direction, and the second side guide plate 3135 and the second fan inlet 3122 are located on the same side of the volute axial direction, such that each side of the centrifugal fan has a first guide plate and a fan inlet.

[0082] The end of the fan outlet duct 313 furthest from the volute body 311 forms the fan outlet 3130. On a cross-section of the fan outlet duct 313 perpendicular to the fan outlet 3130 and parallel to the impeller axis, the circle containing the inner surface of the first side guide plate 3134 passes through the midpoint of the outline of the second fan inlet 3122, and the circle containing the inner surface of the second side guide plate 3133-1 passes through the midpoint of the outline of the first fan inlet 3121. That is, the midpoint of the outline of the second fan inlet 3122 lies on the circle containing the inner surface of the first side guide plate 3134, and the midpoint of the outline of the first fan inlet 3121 lies on the circle containing the inner surface of the second side guide plate 3133-1.

[0083] The inner arc surface of the first guide plate 3133 passes through the midpoint of the chord length of the fan inlet. The arc surface structure of the first guide plate 3133 plays a certain guiding role for the air blown into the fan outlet duct 313, causing it to gather at the arc surface. Compared with the flat-mouth outlet duct in the prior art, it can reduce the influence of airflow blown out by other centrifugal fans, reduce air volume loss and vortex generation, thereby reducing noise.

[0084] In this application, references Figure 6 The diameter of the circle containing the inner side of the first guide vane 3133 is D, and the length of the volute body 311 along the impeller axis is W0, where 1.4W0 ≤ D. If 1.4W0 > D, the curvature of the arc surface at the first guide vane 3133 is larger, and the gradual increase in distance between the two first guide vanes 3133 is smaller. Therefore, the effect of suppressing airflow loss and vortex generation through the involute section will be reduced.

[0085] In some embodiments, D ≤ 1.5W0. If D > 1.5W0, the distance between the two first guide vanes 3133 gradually increases by a large margin, that is, the outward expansion of the two first guide vanes 3133 is large, which will cause the airflow to disperse to the surroundings after leaving the impeller due to the excessively expanded flow channel, which is not conducive to the flow of airflow to the outlet side.

[0086] In some embodiments, 1.4W0≤D≤1.5W0 ensures that the width variation of the involute space between the two first guide vanes 3133 is moderate, so that the airflow will not expand excessively in the flow channel after leaving the impeller 32, thereby reducing pressure loss and maintaining the tendency of the airflow to flow away from the fan assembly 3. This makes the airflow blown out from the indoor unit 100 of the air conditioner more concentrated and regulates the temperature in the indoor area more quickly.

[0087] In some embodiments, the two first guide vanes 3133 are symmetrically arranged, that is, the two first guide vanes 3133 are respectively located on both sides of the fan outlet channel 313 and are symmetrical with respect to the central axis of the fan outlet channel 313. This structural design, through its symmetrical structure, ensures that the airflow is evenly distributed on both sides of the fan outlet channel 313, avoiding the airflow being biased to one side of the fan outlet channel 313 due to an angular difference between one side of the first guide vane 3133 and the other side, and even further causing the formation of local vortices on the fan outlet channel 313. This not only improves the uniformity of the airflow but also enhances the stability and efficiency of the airflow, reduces the noise caused by local vortices formed due to uneven airflow, and improves the quietness performance of the air conditioner indoor unit 100.

[0088] In some embodiments, reference Figure 6 The maximum distance between the two first guide vanes is W1, and the length of the volute body 311 in the impeller axial direction is W0, where 1.02W0 ≤ W1. If 1.02W0 > W1, the degree of outward expansion of the first guide vane 3133 is relatively small, and the effect of suppressing airflow loss and vortex generation through the involute section will be reduced.

[0089] In some embodiments, W1 ≤ 1.06W0. If W1 > 1.06W0, then the first guide vane 3133 expands too much, which will cause the airflow to disperse to the surroundings after leaving the impeller due to the excessively expanded flow channel, which is not conducive to the flow of airflow to the outlet side.

[0090] In some embodiments, 1.02W0≤W1≤1.06W0, the outward expansion space of the involute is moderate, and the flow channel at the involute conforms to the changing trend of the airflow after leaving the impeller, which can reduce the generation of vortices, reduce noise and improve the efficiency of the fan.

[0091] In some embodiments, W1 = 1.04W0. Ensuring that the fan outlet duct provides adequate opening space for the airflow ensures that the airflow leaving the impeller at all axial positions and blowing through the fan outlet duct maintains a direction away from the fan components, thereby further reducing backflow and eddy currents and improving airflow efficiency.

[0092] In some embodiments, refer to Figure 5The connecting segment 3131 includes a volute tongue 3137. The inner surface of the volute tongue 3137 has an arc surface 3138.

[0093] The involute section 3132 is connected to the air outlet side of the arc surface 3138, that is, the involute section 3132 is connected to the side of the arc surface 3138 away from the impeller 32.

[0094] In some embodiments, in the direction perpendicular to the fan outlet 3130, the distance from the fan outlet 3130 to the arc surface 3138 is L1, and the length of the involute 3132 is L, where L≥0.6L1. This ensures that the length of the involute 3132 in the air outlet direction is not too short, thus guaranteeing the guiding effect of the involute 3132 on the airflow.

[0095] In this application, references Figure 2 , Figure 3 and Figure 5 The involute section 3132 includes a second guide plate 3136 connected to two first guide plates 3133. The two second guide plates 3136 are arranged sequentially along a direction perpendicular to the axis of the impeller 32, that is, among the four side plates of the involute section 3132, there are two opposing first guide plates 3133 and two opposing second guide plates 3136.

[0096] The distance between the two second guide vanes 3136 gradually increases along the direction of airflow, causing the internal space of the fan outlet duct 313 to gradually increase away from the volute 31. This structural design results in the fan outlet duct 313 exhibiting a gradually increasing spatial variation from the inside to the outside in two mutually perpendicular directions, guiding the airflow to gradually diffuse in the direction perpendicular to the impeller 32 axis. This wider diffusion range improves the airflow range and uniformity of the air conditioning system. Furthermore, this involute structure allows the airflow to flow smoothly from the impeller 32 and gradually diffuse, thereby reducing local pressure loss at the fan outlet duct 313 and further improving airflow efficiency.

[0097] The upper second guide plate 3136 is located on the extension line of the upper wall of the connecting section 3131, and the lower second guide plate 3136 is inclined downward.

[0098] In some embodiments, reference Figure 3A backflow preventer 314 is provided on the outer surface of the fan outlet duct 313. This structural design allows the backflow preventer 314 to block and suppress the backflow of the blown airflow towards the fan inlet 312. This forces the airflow flowing against the wall outside the fan inlet 312 to pass over the backflow preventer 314 before flowing back into the fan inlet 312. The airflow velocity of the airflow flowing against the wall outside the fan inlet 312 is reduced, preventing the formation of a local air pressure difference due to the presence of high-velocity backflow air outside the fan inlet 312. This avoids airflow turbulence caused by local air pressure differences, reduces noise caused by turbulence, improves the operating efficiency and stability of the air conditioner, and enhances the user experience.

[0099] contrast Figure 7 and Figure 8 It can be observed that, Figure 8 The area of ​​the vortex at the center air outlet is relatively small. Figure 7 The reduction is evident, indicating that the first guide vane guides the airflow from the fan and significantly suppresses the vortex at the fan outlet.

[0100] By comparing an indoor air conditioner unit using a centrifugal fan from the prior art with an indoor air conditioner unit using the centrifugal fan of this application, the following data was obtained:

[0101] project Fan speed (rpm) Total air volume (m³ / min) Existing technology wind turbine components 1060 1473 This application is for wind turbine components. 1060 1516

[0102] As can be seen from the table above, at the same rotational speed, the air volume of the fan assembly of this application is increased by about 3% compared with the prior art after using an involute volute.

[0103] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. An indoor unit for an air conditioner, characterized in that, include: chassis; A fan assembly, disposed within the housing, is used to drive airflow; The fan assembly includes a centrifugal fan, the centrifugal fan comprising: impeller; A volute, which covers the impeller, comprises: The volute body has a fan inlet for supplying air into the volute, and the fan inlet is opposite to the impeller in the axial direction of the impeller. A fan outlet duct, connected to the volute body, is used to allow air to flow out of the volute. The fan outlet duct includes: The connecting section is connected to the volute body; An involute section is connected to the end of the connecting section away from the volute body. The side plates on both sides of the involute section are first guide plates. Two first guide plates are arranged sequentially in a direction parallel to the impeller axis. The first guide plates are arc-shaped, and the distance between the two first guide plates gradually increases in the direction away from the volute body.

2. The indoor unit of the air conditioner according to claim 1, characterized in that, The fan inlet includes a first fan inlet and a second fan inlet arranged opposite to each other; the two first guide plates are a first side guide plate and a second side guide plate; the first side guide plate and the first fan inlet are located on one side of the volute axis, and the second side guide plate and the second fan inlet are located on the other side of the volute axis. The end of the fan outlet channel away from the volute body forms the fan outlet; on the cross section of the fan outlet channel that is perpendicular to the fan outlet and parallel to the axis of the impeller, the midpoint of the outline of the second fan inlet is located on the circle containing the inner side surface of the first side guide plate, and the midpoint of the outline of the first fan inlet is located on the circle containing the inner side surface of the second side guide plate.

3. The indoor unit of the air conditioner according to claim 1, characterized in that, The diameter of the circle containing the inner side of the first guide plate is D, and the length of the volute body along the impeller axis is W0, where 1.4W0≤D≤1.5W0.

4. The indoor unit of the air conditioner according to claim 1, characterized in that, The maximum distance between the two first guide vanes is W1, and the length of the volute body in the axial direction of the impeller is W0, where 1.02W0≤W1≤1.06W0.

5. The indoor unit of the air conditioner according to claim 1, characterized in that, The maximum distance between the two first guide vanes is W1, and the length of the volute body in the axial direction of the impeller is W0, where W1 = 1.04W0.

6. The indoor unit of the air conditioner according to claim 1, characterized in that, The connecting section includes a volute tongue, the inner wall surface of which has an arc surface; the involute section is located on the air outlet side of the arc surface.

7. The indoor unit of the air conditioner according to claim 6, characterized in that, The end of the fan outlet channel away from the volute body forms the fan outlet; in the direction perpendicular to the fan outlet, the distance from the fan outlet to the arc surface is L1, and the length of the involute is L, where L≥0.6L1.

8. The indoor unit of the air conditioner according to claim 1, characterized in that, The fan assembly includes a plurality of centrifugal fans arranged along the axis of the impeller.

9. The indoor unit of the air conditioner according to claim 1, characterized in that, The fan outlet channel includes a second guide plate connected to the two first guide plates.

10. An indoor unit for an air conditioner, characterized in that, include: chassis; A fan assembly, disposed within the housing, is used to drive airflow; The fan assembly includes a centrifugal fan, the centrifugal fan comprising: impeller; A volute, which covers the impeller, comprises: The volute body has a fan inlet for supplying air into the volute, and the fan inlet is opposite to the impeller in the axial direction of the impeller. A fan outlet duct, connected to the volute body, is used to allow air to flow out of the volute. The fan outlet duct includes: The connecting section is connected to the volute body; The involute section is connected to the end of the connecting section away from the volute body. The side plates on both sides of the involute section are first guide plates. The two first guide plates are arranged sequentially in a direction parallel to the impeller axis. The distance between the two first guide plates gradually increases in the direction away from the volute body.

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