Centrifugal fan and air conditioner

Abstract

Embodiments of the present application provide a centrifugal fan and an air conditioner, the centrifugal fan is provided with an air inlet cavity, a volute air duct, an air outlet cavity and an air return cavity, the air inlet cavity, the volute air duct and the air outlet cavity are sequentially communicated; an air inlet end of the air return cavity is arranged on a side wall of the air outlet cavity, an air outlet end of the air return cavity is arranged on a side wall of the air inlet cavity and faces the volute air duct, so as to communicate the air inlet cavity and the air outlet cavity.

Description

Technical Field

[0001] This application relates to the field of air conditioner technology, specifically to a centrifugal fan and an air conditioner. Background Technology

[0002] Centrifugal fans are widely used in air purification, fresh air systems, industrial ventilation, and air conditioning equipment. Their main function is to generate centrifugal force through the high-speed rotation of the impeller, throwing air radially into the volute, where it is then guided to the target area. However, centrifugal fans suffer from low ventilation efficiency and high aerodynamic noise, failing to adequately meet usage requirements. Utility Model Content

[0003] This application provides a centrifugal fan and an air conditioner that can significantly improve ventilation efficiency and reduce aerodynamic noise, thus better meeting usage needs.

[0004] On one hand, this application provides a centrifugal fan with an air inlet duct, a volute duct, an air outlet duct, and a return air duct, wherein the air inlet duct, the volute duct, and the air outlet duct are connected in sequence; the air inlet end of the return air duct is opened on the side wall of the air outlet duct, and the air outlet end of the return air duct is opened on the side wall of the air inlet duct and is arranged towards the volute duct, so as to connect the air inlet duct and the air outlet duct.

[0005] In some embodiments, the angle between the direction of the air outlet of the return air duct and the main airflow direction of the air inlet duct is 5° to 15°.

[0006] In some embodiments, the ratio of the air inlet area of ​​the return air duct to the air outlet area of ​​the return air duct is 5% to 15%.

[0007] In some embodiments, the air outlet duct gradually expands along the air outlet direction, and the expansion angle of the air outlet duct is 7° to 12°.

[0008] In some embodiments, the centrifugal fan includes an air inlet box, a volute, and a centrifugal impeller. The air inlet duct and the air outlet duct are formed in isolation within the air inlet box, the volute duct is formed within the volute, and the centrifugal impeller is disposed within the volute duct.

[0009] In some embodiments, the volute has a first end wall, a second end wall, and a circumferential wall. The first end wall and the second end wall are disposed opposite to each other, and the circumferential wall connects the first end wall and the second end wall to enclose and form the volute air duct. The first end wall is disposed toward the air inlet box. The volute air duct has an air inlet and an air outlet. The air inlet is connected to the air inlet cavity, and the air outlet is connected to the air outlet cavity. The air inlet and the air outlet are respectively disposed on the first end wall.

[0010] In some embodiments, the centrifugal fan further includes a filter structure, the volute duct has an air inlet, the filter structure is disposed in the air inlet duct and blocks the air inlet, and the air outlet of the return air duct is located on the side of the filter structure away from the air inlet of the volute duct.

[0011] In some embodiments, the centrifugal fan is provided with a plurality of return air ducts, which are arranged sequentially at intervals along the circumference of the outlet air duct.

[0012] In some embodiments, the centrifugal fan includes a damper disposed in the return air duct for controlling the return air flow rate of the return air duct.

[0013] On the other hand, this application provides an air conditioner that includes the centrifugal fan provided in any of the above embodiments.

[0014] This embodiment of the application, by setting a return air duct connecting the inlet and outlet air ducts, allows the separated gas formed near the side wall of the outlet air duct to be drawn back into the inlet air duct through the return air duct. This eliminates or at least significantly reduces the risk of turbulence and gas recirculation near the side wall of the outlet air duct, thereby eliminating or at least significantly reducing the obstruction of the outlet airflow caused by turbulence in the gas recirculation zone. Furthermore, the outlet end of the return air duct is positioned towards the volute air duct, allowing the separated gas drawn back into the inlet air duct through the return air duct to enter the volute air duct smoothly along with the inlet airflow from the inlet air duct. This avoids obstruction of the inlet airflow from the separated gas in the inlet air duct and increases the inlet air volume and inlet air pressure of the volute air duct. Thus, through these two effects, the ventilation efficiency of the centrifugal fan is significantly improved and the aerodynamic noise of the centrifugal fan is reduced, better meeting the usage requirements. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 These are isometric structural diagrams of centrifugal fans provided in some embodiments of this application;

[0017] Figure 2 This is a cross-sectional view of a centrifugal fan provided in some embodiments of this application from a first-view perspective;

[0018] Figure 3 This is a cross-sectional view of a centrifugal fan provided in some embodiments of this application from a second perspective;

[0019] Figure 4 This is an exploded structural diagram of a centrifugal fan provided in some embodiments of this application.

[0020] Explanation of key component symbols:

[0021] 1-Centrifugal fan, 10-Air inlet box, 11-Air inlet duct, 12-Air outlet duct, 20-Volume, 21-Volume duct, 211-Air inlet, 212-Air outlet, 22-First end wall, 23-Second end wall, 24-Circumferential wall, 201-First volute component, 202-Second volute component, 30-Return air duct, 40-Centrifugal impeller, 50-Filter structure. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application. Furthermore, 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 indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0025] The use of "applies to" or "configured to" in this application implies open and inclusive language, which does not exclude the applicability to or configuration to devices performing additional tasks or steps. Additionally, the use of "based on" implies openness and inclusivity, because processes, steps, calculations, or other actions "based on" one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated.

[0026] In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be made without using these specific details. In other instances, well-known structures and processes are not described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0027] like Figures 1 to 3 As shown, in one aspect, the present application provides a centrifugal fan 1, which is provided with an air inlet duct 11, a volute duct 21, an air outlet duct 12 and a return air duct 30, which can significantly improve ventilation efficiency and reduce aerodynamic noise, and better meet the needs of use.

[0028] The air inlet duct 11, the volute duct 21, and the air outlet duct 12 are connected in sequence. The air inlet of the return air duct 30 is located on the side wall of the air outlet duct 12, and the air outlet of the return air duct 30 is located on the side wall of the air inlet duct 11 and is oriented towards the volute duct 21, so as to connect the air inlet duct 11 and the air outlet duct 12.

[0029] When the centrifugal fan 1 is working, under the negative pressure generated by the centrifugal fan 1, the air flows through the air inlet duct 11, the volute duct 21 and the air outlet duct 12 in sequence. Most of the airflow in the air outlet duct 12 is delivered outward after passing through the air outlet duct 12, while some airflow is prone to separation near the side wall of the air outlet duct 12. The gas flow separation phenomenon causes the formation of a gas backflow zone near the side wall of the air outlet duct 12. The turbulence in the gas backflow zone will obstruct the airflow of the air outlet duct 12, resulting in a significant reduction in the ventilation efficiency of the centrifugal fan 1 and a significant increase in aerodynamic noise.

[0030] Thanks to the arrangement of the return air duct 30 and its connection with the inlet air duct 11 and the outlet air duct 12, the separated gas formed near the side wall of the outlet air duct 12 can be drawn back into the inlet air duct 11 through the return air duct 30. This eliminates or at least significantly reduces the risk of turbulence and gas recirculation near the side wall of the outlet air duct 12, thereby eliminating or at least significantly reducing the obstruction of the gas recirculation zone to the outlet airflow of the outlet air duct 12. Furthermore, the outlet end of the return air duct 30 is positioned towards the volute air duct 21, allowing the separated gas drawn back into the inlet air duct 11 through the return air duct 30 to enter the volute air duct 21 smoothly along with the inlet airflow of the inlet air duct 11. This avoids obstruction of the inlet airflow of the inlet air duct 11 by the separated gas, increasing the inlet air volume and inlet air pressure of the volute air duct 21. Thus, through the aforementioned two effects, the ventilation efficiency of the centrifugal fan 1 is significantly improved and the aerodynamic noise of the centrifugal fan 1 is reduced, better meeting the usage requirements. Compared with related technologies, the centrifugal fan 1 provided in this application embodiment has the advantages of higher ventilation efficiency and lower aerodynamic noise.

[0031] In some embodiments, the angle between the direction of the air outlet of the return air duct 30 and the main airflow direction of the inlet air duct 11 can be 5° to 15°, for example, 5°, 7°, 9°, 10°, 11°, 13°, or 15°. Here, the main airflow direction of the inlet air duct 11 refers to the direction of the incoming airflow in the inlet air duct 11. Within this angle range, when the return air duct 30 draws the separated gas back to the inlet air duct 11 to form a return airflow, the wind direction of the return airflow entering the inlet air duct 11 is approximately the same as the main airflow direction of the inlet air duct 11. The return airflow and the incoming airflow of the inlet air duct 11 can mix more smoothly, further reducing the risk of the separated gas obstructing the incoming airflow of the inlet air duct 11, and increasing the airflow volume and airflow pressure of the volute duct 21.

[0032] In some embodiments, the ratio of the inlet area of ​​the return air duct 30 to the flow cross-sectional area of ​​the outlet air duct 12 can be 5% to 15%, for example, values ​​such as 5%, 7%, 9%, 10%, 11%, 13%, or 15%. Within the above-mentioned ratio range, the recirculation ratio of the return air duct 30 to the airflow in the outlet air duct 12 is suitable, which will not affect the flow of the main outlet airflow in the outlet air duct 12, and can effectively eliminate or at least greatly reduce the risk of turbulence and gas recirculation zone forming near the sidewall of the outlet air duct 12.

[0033] In some embodiments, the air outlet duct 12 can gradually expand along the air outlet direction, which can slow down the airflow velocity of the air outlet duct 12 and increase the static pressure of the centrifugal fan 1. The degree of expansion of the air outlet duct 12 can be determined according to actual needs, and this application embodiment does not limit it. In some examples, the expansion angle of the air outlet duct 12 can be 7° to 12°, for example, 7°, 8°, 9°, 10°, 11° or 12°.

[0034] In some embodiments, the centrifugal fan 1 may include an air inlet box 10, a volute 20, and a centrifugal impeller 40. The air inlet duct 11 and the air outlet duct 12 are formed in the air inlet box 10 in a mutually isolated manner, the volute duct 21 is formed in the volute 20, and the centrifugal impeller 40 is disposed in the volute duct 21.

[0035] In some examples, the volute 20 may have a first end wall 22, a second end wall 23, and a circumferential wall 24. The first end wall 22 and the second end wall 23 are arranged opposite each other, and the circumferential wall 24 connects the first end wall 22 and the second end wall 23 to enclose and form a volute air duct 21. The first end wall 22 is positioned towards the air inlet box 10, and the second end wall 23 is spaced apart on the side of the first end wall 22 away from the air inlet box 10. The volute air duct 21 may have an air inlet 211 and an air outlet 212. The air inlet 211 is connected to the air inlet cavity 11, and the air outlet 212 is connected to the air outlet cavity 12. The air inlet 211 and the air outlet 212 are respectively disposed on the first end wall 22. By arranging the air inlet 211 and the air outlet 212 of the volute air duct 21 on the same side, the space utilization rate can be improved, the volume of the centrifugal fan 1 can be reduced, and the centrifugal fan 1 can be made more compact and small.

[0036] like Figures 1 to 4 As shown, in some examples, the volute 20 may include a first volute component 201 and a second volute component 202, which together form a volute air duct 21. By setting the volute 20 as a split structure, the manufacturing difficulty and cost of the volute 20 can be reduced.

[0037] In some embodiments, the centrifugal fan 1 may further include a filter structure 50. The volute duct 21 has an air inlet 211, and the filter structure 50 is disposed in the air inlet duct 11 and blocks the air inlet 211 to filter and purify the air entering the air inlet 211 from the air inlet duct 11. The type of filter structure 50 can be determined according to actual needs, and various types of filter screens and their combinations can be used. This application embodiment does not limit this. Here, the air outlet of the return air duct 30 can be located on the side of the filter structure 50 away from the air inlet 211 of the volute duct 21, so that the return airflow formed by the return air duct 30 can be smoothly and evenly mixed with the airflow entering the air inlet duct 11, and after mixing, it flows through the filter structure 50 and enters the air inlet 211 of the volute duct 21.

[0038] The number of return air ducts 30 can be determined according to actual needs, and can be one or more; this application embodiment does not limit this. In some embodiments, the centrifugal fan 1 can be provided with multiple return air ducts 30, and the multiple return air ducts 30 can be arranged sequentially at intervals along the circumference of the outlet air duct 12. Here, the sidewall of the outlet air duct 12 extends along the circumference of the outlet air duct 12 to enclose and form the outlet air duct 12. In this way, the multiple return air ducts 30 can draw back the separated gas at different positions on the sidewall of the outlet air duct 12 along the circumference of the outlet air duct 12 to the inlet air duct 11, effectively eliminating or at least greatly reducing the risk of turbulence and gas backflow zone forming near the sidewall of the outlet air duct 12.

[0039] In some embodiments, the centrifugal fan 1 may include a damper (not shown) disposed in the return air duct 30 to control the return air flow rate of the return air duct 30. This allows the opening degree of the damper to be adjusted according to actual operating conditions, matching the return air flow rate of the return air duct 30 with actual needs, thereby maintaining optimal ventilation efficiency and aerodynamic noise of the centrifugal fan 1. For example, the opening degree of the damper can be controlled according to the fan speed setting of the centrifugal fan 1 to match the return air flow rate of the return air duct 30 with the air volume requirement of the centrifugal impeller 40.

[0040] On the other hand, this application provides an air conditioner that includes the centrifugal fan 1 provided in any of the above embodiments. The type of air conditioner can be determined according to actual needs, and can be, for example, a wall-mounted air conditioner, a cabinet air conditioner, a window air conditioner, a ceiling-mounted air conditioner, etc., and this application does not limit this type. The air conditioner provided in this application, with the aforementioned centrifugal fan 1, can significantly improve ventilation efficiency and reduce aerodynamic noise, thus better meeting usage needs.

[0041] The centrifugal fan and air conditioner provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A centrifugal fan, characterized in that, The device includes an air inlet duct, a volute duct, an air outlet duct, and a return air duct, which are connected in sequence. The air inlet of the return air duct is located on the side wall of the air outlet duct, and the air outlet of the return air duct is located on the side wall of the air inlet duct and faces the volute duct, so as to connect the air inlet duct and the air outlet duct.

2. The centrifugal fan according to claim 1, characterized in that, The angle between the direction of the air outlet of the return air duct and the direction of the main airflow of the air inlet duct is 5° to 15°.

3. The centrifugal fan according to claim 1, characterized in that, The ratio of the cross-sectional area of ​​the air inlet of the return air duct to that of the air outlet duct is 5% to 15%.

4. The centrifugal fan according to claim 1, characterized in that, The air outlet duct gradually expands along the air outlet direction, and the expansion angle of the air outlet duct is 7° to 12°.

5. The centrifugal fan according to claim 1, characterized in that, The centrifugal fan includes an air inlet box, a volute, and a centrifugal impeller. The air inlet cavity and the air outlet cavity are formed in isolation within the air inlet box. The volute duct is formed within the volute, and the centrifugal impeller is disposed within the volute duct.

6. The centrifugal fan according to claim 5, characterized in that, The volute has a first end wall, a second end wall, and a circumferential wall. The first end wall and the second end wall are arranged opposite to each other. The circumferential wall connects the first end wall and the second end wall to enclose and form the volute air duct. The first end wall is arranged towards the air inlet box. The volute air duct has an air inlet and an air outlet. The air inlet is connected to the air inlet cavity, and the air outlet is connected to the air outlet cavity. The air inlet and the air outlet are respectively arranged on the first end wall.

7. The centrifugal fan according to claim 1, characterized in that, The centrifugal fan also includes a filter structure. The volute air duct has an air inlet. The filter structure is disposed in the air inlet cavity and blocks the air inlet. The air outlet of the return air cavity is located on the side of the filter structure away from the air inlet of the volute air duct.

8. The centrifugal fan according to claim 1, characterized in that, The centrifugal fan is provided with multiple return air ducts, which are arranged sequentially at intervals along the circumference of the outlet air duct.

9. The centrifugal fan according to claim 1, characterized in that, The centrifugal fan includes a valve, which is disposed in the return air duct and is used to control the return air flow rate of the return air duct.

10. An air conditioner, characterized in that, The centrifugal fan included in any one of claims 1-9.

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