Axial flow fan blade, axial flow fan and air conditioner thereof

Abstract

The application provides an axial flow fan blade, an axial flow fan and an air conditioner thereof, and belongs to energy-saving air conditioning equipment. The axial flow fan blade comprises at least two interval arranged blades, the blade comprises a leading edge and a trailing edge, the trailing edge is provided with a first tooth structure, a second tooth structure and a groove structure, the groove structure is located between the first tooth structure and the second tooth structure, the first tooth structure comprises at least one first groove, the second tooth structure comprises at least one second groove, the groove structure comprises at least one third groove, and in the projection plane of the plane perpendicular to the axis of the axial flow fan blade, the area of the single groove of the first groove is smaller than the area of the single groove of the third groove, and the area of the single groove of the second groove is smaller than the area of the single groove of the third groove. According to the application, the problems that the power loss is large, the operation noise is high and the power and noise cannot be optimized simultaneously due to large scale vortex caused by airflow separation of the trailing edge when the axial flow fan blade operates at high air volume can be solved.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, specifically to an axial flow fan blade, an axial flow fan and its air conditioner, which belongs to energy-saving air conditioning equipment. Background Technology

[0002] Axial fan blades are core components of both indoor and outdoor air conditioning units, and their performance directly determines airflow, noise levels, and energy consumption. Traditional axial fan blade trailing edges are typically designed with a smooth, streamlined shape or a simple single-sided bend. While this design performs adequately at low airflow speeds, under high airflow conditions, the airflow over the trailing edge easily generates a large pressure gradient, leading to boundary layer separation and the formation of large-scale vortex shedding. These vortices not only increase aerodynamic drag (resulting in increased motor power) but also generate strong broadband noise.

[0003] To address these issues, existing technologies attempt to introduce serrated structures at the blade trailing edge, using these serrations to break up large vortices and transform them into smaller-scale turbulence to reduce noise. However, most existing serrated structures employ uniformly distributed single-size serrations, or only a small number of serrations in specific areas. This simplistic design has significant drawbacks: while reducing noise, it often sacrifices airflow, or fails to achieve synergistic optimization of power and noise.

[0004] Because existing axial flow fan blades suffer from high power loss and high operating noise due to large-scale vortices generated by trailing edge airflow separation during high airflow operation, and cannot achieve synergistic optimization of power and noise, this invention researches and designs an axial flow fan blade, an axial flow fan and its air conditioner, which belongs to energy-saving air conditioning equipment. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the prior art in which the axial flow fan blades have large power loss and high operating noise caused by the large-scale vortex generated by the tail edge airflow separation when operating at high air volume, and cannot achieve synergistic optimization of power and noise. Thus, the present invention provides an axial flow fan blade, an axial flow fan and its air conditioner, which belong to the category of energy-saving air conditioning equipment.

[0006] To address the above problems, the present invention provides an axial flow fan blade, comprising:

[0007] The blade has at least two spaced-apart blades, each blade including a leading edge and a trailing edge, the leading edge being located on the windward side of the blade and the trailing edge being located on the leeward side of the blade.

[0008] The trailing edge is provided with a first tooth-like structure, a second tooth-like structure, and a groove structure. The groove structure is located between the first tooth-like structure and the second tooth-like structure. The first tooth-like structure includes at least one first groove, the second tooth-like structure includes at least one second groove, and the groove structure includes at least one third groove. In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, the area of ​​a single groove of the first groove is smaller than the area of ​​a single groove of the third groove, and the area of ​​a single groove of the second groove is smaller than the area of ​​a single groove of the third groove.

[0009] In some implementations...

[0010] The first tooth-like structure includes at least one first tooth connected to the first groove. The second tooth-like structure includes at least one second tooth connected to the second groove. The third groove is at least one, with one end connected to the first tooth and the other end connected to the second tooth. In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, along the radial direction of the axial flow fan blade, the first tooth is connected to the radially outer side of the third groove, and the second tooth is connected to the radially inner side of the third groove.

[0011] In some implementations...

[0012] It also includes a hub, and the blades are disposed on the outer periphery of the hub, with at least two blades spaced apart along the circumferential direction of the hub;

[0013] In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, along the radial direction of the axial flow fan blade, multiple positions of the radial outermost ends of all the blades are located on the same circumference, which is a first circle whose center coincides with the center of the axial flow fan blade, and the radius of the first circle is R; the radial outermost ends of the hub are located on the same circumference, which is a second circle whose center coincides with the center of the axial flow fan blade, and the radius of the second circle is Rhub;

[0014] In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, the distance between the position on the trailing edge and the center of the axial flow fan blade is ri. Along the radial extension direction on the trailing edge, the effective working radius L = R - Rhub is defined, and the normalized coordinate parameter ρ = (ri - Rhub) / L is introduced to divide the trailing edge into three functional zones:

[0015] Outer functional area I: corresponding to the dimensionless normalized coordinate parameter ρ∈[0.677,1], the first tooth-shaped structure is set;

[0016] Inner functional area II: corresponding to the dimensionless normalized coordinate parameter ρ∈[0,0.365], the second tooth-shaped structure is set;

[0017] Intermediate control area III: The groove structure is set for the dimensionless normalized coordinate parameter ρ∈[0.365,0.677].

[0018] The value of ρ is in the range of [0, 1].

[0019] In some implementations...

[0020] The third groove has a groove center. The first toothed structure and the second toothed structure are asymmetrically arranged with respect to the groove center. Along the radial direction from the inside to the outside, the effective working radius at the second circle is 0, the effective working radius at the first circle is L, and the minimum distance from the groove center to the hub is greater than or equal to 40%L and less than or equal to 60%L.

[0021] In some implementations...

[0022] In the first tooth-shaped structure, a plurality of first teeth are equidistantly distributed along the radial direction; in the second tooth-shaped structure, a plurality of second teeth are equidistantly distributed along the radial direction, and the number of second teeth is different from the number of first teeth.

[0023] In some implementations...

[0024] In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, the ratio of the tooth height to the tooth width of the first tooth is greater than or equal to 0.5 and less than or equal to 0.8, and the ratio of the chamfer radius at the bottom of the first tooth to the tooth height of the first tooth is greater than or equal to 0.1 and less than or equal to 0.2; and / or, the ratio of the tooth height to the tooth width of the second tooth 42 is greater than or equal to 0.5 and less than or equal to 0.8, and the ratio of the chamfer radius at the bottom of the second tooth 42 to the tooth height of the second tooth 42 is greater than or equal to 0.1 and less than or equal to 0.2;

[0025] And / or, in the projection plane of the plane perpendicular to the axis of the axial fan blade, the inner wall of the third groove is a smooth curved surface.

[0026] In some implementations...

[0027] The tooth width of the first tooth is Wi, which is greater than or equal to 5 mm and less than or equal to 8 mm; the radius of the bottom chamfer of the first tooth is Ri, which is greater than or equal to 0.2 mm and less than or equal to 0.5 mm; the tooth height of the first tooth is Hi, which is greater than or equal to 2.0 mm and less than or equal to 3.5 mm; and / or,

[0028] The second tooth has a tooth width of Wi, which is greater than or equal to 5 mm and less than or equal to 8 mm; the radius of the bottom chamfer of the second tooth is Ri, which is greater than or equal to 0.2 mm and less than or equal to 0.5 mm; and the tooth height of the second tooth is Hi, which is greater than or equal to 2.0 mm and less than or equal to 3.5 mm.

[0029] In some implementations...

[0030] The first tooth and / or the second tooth are isosceles triangles; and / or,

[0031] The ratio of the tooth width of the first tooth to the tooth width of the second tooth is greater than or equal to 0.8 and less than or equal to 1.2; and / or, the ratio of the tooth height of the first tooth to the tooth height of the second tooth is greater than or equal to 0.8 and less than or equal to 1.2.

[0032] In some implementations...

[0033] In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, the ratio between the groove height of the third groove and the tooth height of the first tooth is greater than or equal to 8.5 and less than or equal to 14.0, the ratio between the groove height of the third groove and the tooth height of the second tooth is greater than or equal to 8.5 and less than or equal to 14.0, the ratio between the groove width of the third groove and the tooth width of the first tooth is greater than or equal to 7.5 and less than or equal to 12.5, and the ratio between the groove width of the third groove and the tooth width of the second tooth is greater than or equal to 7.5 and less than or equal to 12.5.

[0034] In some implementations...

[0035] In the projection plane of a plane perpendicular to the axis of the axial flow fan blade: the innermost radial positions of the second teeth of all blades are located on the same circumference, which is a third circle whose center coincides with the center of the axial flow fan blade, and the radius of the third circle is r1; the outermost radial positions of the second teeth of all blades are located on the same circumference, which is a fourth circle whose center coincides with the center of the axial flow fan blade, and the radius of the fourth circle is r2; and r1 < r2, the distance from the second tooth to the center of the axial flow fan blade is greater than or equal to r1 and less than or equal to r2;

[0036] The innermost radial position of the first tooth of all blades is located on the same circumference, which is the fifth circle, whose center coincides with the center of the axial flow blade, and the radius of the fifth circle is r3; the outermost radial position of the first tooth of all blades is located on the same circumference, which is the sixth circle, whose center coincides with the center of the axial flow blade, and the radius of the sixth circle is r4; and r3 < r4, the distance from the first tooth to the center of the axial flow blade is greater than or equal to r3 and less than or equal to r4.

[0037] In some implementations...

[0038] In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, the groove height of the third groove is H, and the groove width of the third groove is W. The two satisfy the cubic function mathematical relationship: W=aH³+bH²+cH+d, where H∈[15,40]mm and W∈[30,70]mm. The allowable range of each coefficient is: a∈[0.000036,0.000044], b∈[-0.05192,-0.04248], c∈[1.9919,2.4345], d∈[0.4272,0.5222].

[0039] The present invention also provides an axial flow fan, which includes the aforementioned axial flow fan blades.

[0040] The present invention also provides an air conditioner that includes the aforementioned axial flow fan.

[0041] The axial flow fan blade, axial flow fan and air conditioner provided by the present invention have the following beneficial effects:

[0042] 1. This invention provides an axial flow fan blade, belonging to energy-saving air conditioning equipment. By setting a first toothed structure, a second toothed structure, and a groove structure on the trailing edge, the groove structure is located between the first toothed structure and the second toothed structure. The first toothed structure includes at least one first groove, the second toothed structure includes at least one second groove, and the groove structure includes at least one third groove. In the projection plane of a plane perpendicular to the axis of the axial flow fan blade, the area of ​​the first groove is smaller than the area of ​​the third groove, and the area of ​​the second groove is smaller than the area of ​​the third groove. This structure can form small serrations on both the radially outer and radially inner sides, and effectively form a large groove between the two small serrations. During operation, when the fan blade rotates, the airflow passing through the trailing edge is first divided into several fine small vortices by the small serrations on the outer and inner sides, interrupting the continuous large-scale vortex shedding process, thereby reducing high-frequency noise. Subsequently, the large groove on the middle side, utilizing its unique asymmetrical structure and smooth curved surface, further guides and rectifyes the remaining mainstream airflow, optimizing the airflow separation point and reducing pressure resistance. This combined design strategy of "two sets of small sawtooth arrays + large groove on the middle side" allows the fan blade to significantly reduce operating power while maintaining the original airflow, and at the same time, the noise level is significantly improved. Experimental data shows that compared with the traditional smooth trailing edge, the solution in this embodiment can reduce power by about 3W (about 10%) and reduce noise by 3-4 decibels under the same airflow, achieving synergistic optimization of power and noise. This invention provides an axial flow fan blade with a multi-stage sawtooth structure that can be differentiated according to the radial position characteristics of the fan blade, achieving significant noise reduction and energy saving without sacrificing airflow. It effectively solves the problem that axial flow fan blades, when operating at high airflow, suffer from high power loss and high operating noise due to large-scale vortices generated by trailing edge airflow separation, making it impossible to achieve synergistic optimization of power and noise.

[0043] 2. Furthermore, the present invention employs a dimensional structure design for the small serrations on the radially outer and radially inner sides, combined with a bottom chamfer design, to make the airflow smoother when passing through the tooth tips, reducing local dead zones, improving the uniformity and stability of the airflow, and avoiding additional friction losses caused by sharp chamfers; this solves the problem of large local flow losses and achieves the effect of improving flow stability. Furthermore, the present invention uses a smooth transition curved surface (such as an ellipse) on the inner wall of the large groove (third groove) set on the middle side, which enhances the control capability of the trailing edge region over the mainstream, optimizes the position of the airflow separation point, and further improves the overall aerodynamic efficiency; this solves the problem of weak trailing edge control capability and achieves the effect of enhancing aerodynamic efficiency. Attached Figure Description

[0044] Figure 1 This is a front view structural diagram of an axial flow fan blade in existing technology;

[0045] Figure 2 This is a front view structural diagram of the axial flow fan blade of the present invention;

[0046] Figure 3 yes Figure 2 Dimensional structural diagrams of the first tooth-shaped structure, the second tooth-shaped structure, and the groove structure;

[0047] Figure 4 yes Figure 3 A magnified view of part A in the image;

[0048] Figure 5 yes Figure 3 A magnified view of part B in the image;

[0049] Figure 6 yes Figure 5 A magnified view of part C;

[0050] Figure 7 This is a curve showing the relationship between the tooth width and tooth height in the trailing edge III region (large tooth) of the axial flow fan blade of the present invention;

[0051] Figure 8 This is a comparison diagram of the simulated pressure surface pressure of the axial flow fan blade of the present invention (right) and the existing axial flow fan blade (left);

[0052] Figure 9 This is a comparison diagram of the simulated suction surface pressure of the axial flow fan blade of the present invention (right) and the existing axial flow fan blade (left);

[0053] Figure 10 This is a power efficiency curve comparing the axial flow fan blade of the present invention with that of an existing axial flow fan blade;

[0054] Figure 11 This is a noise effect curve comparing the axial flow fan blade of the present invention with that of an existing axial flow fan blade.

[0055] The reference numerals in the attached figures are as follows:

[0056] 1. Blade; 11. Leading edge; 12. Trailing edge; 2. Hub; 3. First tooth-like structure; 31. First groove; 32. First tooth; 4. Second tooth-like structure; 41. Second groove; 42. Second tooth; 5. Groove structure; 51. Third groove. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0059] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0060] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms 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 on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0061] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0062] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0063] like Figure 2-11 The present invention provides an axial flow fan blade, comprising:

[0064] At least two spaced-apart blades 1, each blade 1 including a leading edge 11 and a trailing edge 12, wherein the leading edge 11 is located on the windward side of the blade 1, and the trailing edge 12 is located on the leeward side of the blade 1.

[0065] The trailing edge 12 is provided with a first tooth-like structure 3, a second tooth-like structure 4, and a groove structure 5. The groove structure 5 is located between the first tooth-like structure 3 and the second tooth-like structure 4. The first tooth-like structure 3 includes at least one first groove 31, the second tooth-like structure 4 includes at least one second groove 41, and the groove structure 5 includes at least one third groove 51. In the projection plane of a plane perpendicular to the axis of the axial flow fan blade, the area of ​​a single groove of the first groove 31 is smaller than the area of ​​a single groove of the third groove 51, and the area of ​​a single groove of the second groove 41 is smaller than the area of ​​a single groove of the third groove 51. (In this invention, there can be one or more first grooves. When there are two or more, their structures are either identical or different. Regardless of whether the structures are identical or different, the area of ​​a single groove of the first groove is smaller than the area of ​​a single groove of the third groove. Similarly, there can be one or at least two second grooves. When there are at least two second grooves, their structures are either identical or different. Regardless of whether the structures are identical or different, the area of ​​a single groove of the second groove is smaller than the area of ​​a single groove of the third groove. The third groove of this invention can also be one or at least two.)

[0066] This invention provides an axial flow fan blade as described above, belonging to energy-saving air conditioning equipment. By setting a first toothed structure, a second toothed structure, and a groove structure on the trailing edge, the groove structure is located between the first toothed structure and the second toothed structure. The first toothed structure includes at least one first groove, the second toothed structure includes at least one second groove, and the groove structure includes at least one third groove. In the projection plane of a plane perpendicular to the axis of the axial flow fan blade, the area of ​​a single groove in the first groove is smaller than the area of ​​a single groove in the third groove, and the area of ​​a single groove in the second groove is smaller than the area of ​​a single groove in the third groove. This structure forms small serrations on both the radially outer and radially inner sides, and effectively forms a large groove (or large serration, hereinafter the same) between the two small serrations. During operation, when the fan blade rotates, the airflow passing through the trailing edge is first divided into several fine small vortices by the small serrations on the outer and inner sides, interrupting the continuous flow. The large-scale vortex shedding process reduces high-frequency noise. Subsequently, the large groove on the middle side, with its special asymmetric structure and smooth curved surface, further guides and rectifies the remaining mainstream, optimizes the airflow separation point, and reduces pressure resistance. This combination design strategy of "two sets of small sawtooth arrays + large groove on the middle side" enables the fan blade to significantly reduce operating power while maintaining the original airflow, and at the same time, the noise level is significantly improved. Experimental data shows that compared with the traditional smooth trailing edge, the scheme in this embodiment can reduce power by about 3W (about 10%) and reduce noise by 3-4 decibels under the same airflow, and can achieve synergistic optimization of power and noise. This invention provides an axial flow fan blade with a multi-stage sawtooth structure that can be differentiated according to the radial position characteristics of the fan blade, and can achieve significant noise reduction and energy saving without sacrificing airflow. It effectively solves the problem of high power loss and high operating noise caused by large-scale vortices generated by trailing edge airflow separation when the axial flow fan blade is running at high airflow.

[0067] In some implementations...

[0068] The first tooth-like structure 3 includes at least one first tooth 32, which is connected to the first groove 31 (two or more first teeth + first grooves form a first serration structure). The second tooth-like structure 4 includes at least one second tooth 42 (two or more second teeth + second grooves form a second serration structure), which is connected to the second groove 41. The third groove 51 is at least one, with one end connected to the first tooth 32 and the other end connected to the second tooth 42. In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, along the radial direction of the axial flow fan blade, the first tooth 32 is connected to the radially outer side of the third groove 51 (the radial direction is from the center of the axial flow fan blade to the outer circle of the blade, and the first tooth is located on the radially outer side of the third groove, i.e., the first tooth is far away from the center of the axial flow fan blade relative to the third groove). The second tooth 42 is connected to the radially inner side of the third groove 51 (the radial direction is from the center of the axial flow fan blade to the outer circle of the blade, and the second tooth is located on the radially inner side of the third groove, i.e., the second tooth is close to the center of the axial flow fan blade relative to the third groove).

[0069] This is a further preferred structural form of the multi-stage sawtooth structure axial flow fan blade with differentiated design of the present invention. Specifically, the first tooth-like structure on the radially outer side includes at least one first tooth, and the first groove is connected to the first tooth. The second tooth-like structure on the radially inner side includes at least one second tooth, and the second groove is connected to the second tooth. The third groove of the groove structure is at least one (preferably an independent large groove or large sawtooth). Working principle and effect analysis: During operation, when the fan blade rotates, the airflow passes through the trailing edge. The small sawtooths on the outer and inner sides first divide the mainstream into several fine small vortices, interrupting the continuous large-scale vortex shedding process, thereby reducing high-frequency noise. Subsequently, the large groove on the middle side, utilizing its special asymmetric structure and smooth curved surface, further guides and rectifyes the remaining mainstream, optimizing the airflow separation point and reducing pressure drag. This combined design strategy of "two sets of equidistant small sawtooth arrays + an independent large groove on the middle side" allows the fan blade to maintain its original airflow while significantly reducing operating power and improving noise levels. Experimental data shows that, compared to traditional smooth trailing edges, this embodiment can reduce power consumption by approximately 3W (about 10%) and noise by 3-4 decibels under the same airflow. Figure 10-11 .

[0070] In some implementations...

[0071] It also includes a hub 2, and the blades 1 are disposed on the outer periphery of the hub 2, with at least two blades 1 spaced apart along the circumferential direction of the hub 2;

[0072] In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, along the radial direction of the axial flow fan blade, the outermost radial ends of all the blades 1 are located on the same circumference, which is a first circle whose center coincides with the center of the axial flow fan blade, and the radius of the first circle is R; the outermost radial ends of the hub 2 are located on the same circumference, which is a second circle whose center coincides with the center of the axial flow fan blade, and the radius of the second circle is Rhub;

[0073] In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, the distance between the position on the trailing edge 12 and the center of the axial flow fan blade is ri. Along the radial extension direction from the inside to the outside on the trailing edge 12, the effective working radius L = R - Rhub is defined, and a normalized coordinate parameter ρ = (ri - Rhub) / L is introduced to divide the trailing edge 12 into three functional zones:

[0074] Outer functional area I (high frequency area): corresponding to the dimensionless normalized coordinate parameter ρ∈[0.677,1], the first tooth-shaped structure 3 is set;

[0075] Inner functional area II (low frequency area): corresponding to the dimensionless normalized coordinate parameter ρ∈[0,0.365], the second tooth structure 4 is set;

[0076] Intermediate control zone III (separation control zone): corresponding to the dimensionless normalized coordinate parameter ρ∈[0.365,0.677], the groove structure 5 is set;

[0077] The value of ρ is in the range of [0, 1].

[0078] This invention provides an axial flow fan blade for use in household split air conditioners, unlike existing fan blades such as... Figure 1 Compared with existing fan blades, the axial flow fan blade of this invention includes a hub, at least two blades, and a multi-stage serrated structure located at the trailing edge of the blades. Figure 2 The core innovation of this invention lies in the refined aerodynamic design of the trailing edge region of the blade.

[0079] The regional division and overall layout of this invention are as follows: Figure 3 As shown, to accommodate the differences in airflow characteristics at different radial positions, the trailing edge region is non-uniformly divided into three functional zones along the radial extension line from the hub to the blade tip. Let the total outer diameter of the blade be R, the hub radius be Rhub, and the effective working radius be defined as L = R - Rhub. A normalized coordinate system ρ = (ri - Rhub) / L is introduced, where ri is the radial distance of the current point, and ρ ranges from 0 to 1. In this embodiment, the preferred total blade diameter is 445 mm (i.e., R = 222.5 mm), the hub radius Rhub = 75.5, and the effective working radius L = 147 mm.

[0080] The three functional areas are divided as follows:

[0081] Outer functional zone I (high frequency zone): corresponding to ρ∈[0.677,1], this zone mainly deals with high frequency turbulence generated by high-speed airflow at the blade tip;

[0082] Inner functional zone II (low frequency zone): corresponding to ρ∈[0,0.365], this zone mainly deals with low-frequency vortices generated by low-speed airflow at the blade root;

[0083] Intermediate Control Zone III (Separation Control Zone): Corresponding to ρ∈[0.365,0.677], this area is the main location for airflow separation and is used to arrange large grooves;

[0084] Therefore, the present invention optimizes the distribution of the first tooth structure, the second tooth structure, and the groove structure through the above-mentioned structure. This effectively handles the high-frequency turbulence generated by the high-speed airflow at the blade tip through the outer first tooth structure, effectively handles the low-frequency vortices generated by the low-speed airflow at the blade root through the inner second tooth structure, and effectively handles airflow separation through the middle groove structure. This suppresses the generation of large-scale vortices and disperses energy dissipation, thereby significantly reducing operating power under the same air volume. The large groove in the middle breaks up large vortices, and the small serrations on both sides break up small vortices, which can synergistically reduce noise, reduce energy consumption, and improve energy efficiency.

[0085] In some implementations...

[0086] The third groove 51 has a groove center. The first tooth structure 3 and the second tooth structure 4 are asymmetrically arranged with respect to the groove center. Along the radial direction from the inside to the outside, the effective working radius at the second circle is 0, the effective working radius at the first circle is L, and the minimum distance from the groove center to the hub 2 is greater than or equal to 40%L and less than or equal to 60%L.

[0087] Through the above-described preferred arrangement, the present invention can asymmetrically arrange the center of the large groove between the high-frequency region (first tooth structure) and the low-frequency region (second tooth structure) according to the airflow separation characteristics, preferably at 40% to 60% of the effective radius L. This can further limit the setting range of the large groove in the middle, better correspond to the separation zone, improve the effect of suppressing airflow separation and generating large-scale vortices, further reduce airflow separation, break up large vortices, improve energy efficiency, reduce operating power, reduce energy consumption, and reduce noise.

[0088] In this invention, L is the difference between the outer diameter R of the blade and the radius Rhub of the hub, that is, the radial distance between the outer diameter of the blade and the outer diameter of the hub. This difference is assumed to exist for any axial flow blade. The figure illustrates R and Rhub, so L = R - Rhub can be obtained. L can also be understood as the radial length of the trailing edge projected in the radial direction of the blade.

[0089] Regarding the explanation of L's 40%~60%, 50% of L is the exact middle position of the projected length of the trailing edge in the direction of the blade radius. With an additional 10% margin on both sides, the range of 40%-60% is obtained. The large groove design is located in this range, closer to the middle position of the trailing edge.

[0090] In some implementations...

[0091] In the first tooth structure 3, a plurality of first teeth 32 are equidistantly distributed along the radial direction; in the second tooth structure 4, a plurality of second teeth 42 are equidistantly distributed along the radial direction, and the number of second teeth 42 is different from the number of first teeth 32.

[0092] The present invention, through the preferred configuration of the first tooth structure and the second tooth structure, can uniformly process the high-frequency turbulence generated by the high-speed airflow at the blade tip in the high-frequency region located on the radial outer side through the equidistantly distributed first teeth, breaking up the high-frequency small eddies there. In the low-frequency region located on the radial inner side, the equidistantly distributed second teeth can uniformly process the low-frequency eddies generated by the low-speed airflow at the blade root, breaking up the low-frequency small eddies there. This further reduces airflow separation, reduces noise, increases airflow force, reduces energy consumption, and improves the energy efficiency of the wind turbine blade.

[0093] In some implementations...

[0094] In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, the ratio of the tooth height to the tooth width of the first tooth 32 is greater than or equal to 0.5 and less than or equal to 0.8, and the ratio of the chamfer radius at the bottom of the first tooth 32 to the tooth height of the first tooth 32 is greater than or equal to 0.1 and less than or equal to 0.2; and / or, the ratio of the tooth height to the tooth width of the second tooth 42 is greater than or equal to 0.5 and less than or equal to 0.8, and the ratio of the chamfer radius at the bottom of the second tooth 42 to the tooth height of the second tooth 42 is greater than or equal to 0.1 and less than or equal to 0.2 (in this invention, "~" indicating a numerical range includes the endpoint values ​​at both ends).

[0095] In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, the inner wall of the third groove 51 is a smooth curved surface (the inner wall shape of the third groove 51 is preferably a symmetrical curve such as a circle, ellipse, or parabola, or a composite curve profile of asymmetrical curves such as non-circular, non-elliptical, or non-parabolic).

[0096] Furthermore, the present invention limits the size of the small serrations on the radially outer and radially inner sides to the above-mentioned range, and combines them with a bottom chamfer design, which makes the airflow smoother when passing through the tooth tip, reduces local dead zones, improves the uniformity and stability of the airflow, and avoids additional friction loss caused by sharp chamfers; it solves the problem of large local flow loss and achieves the effect of improving flow stability.

[0097] Furthermore, the present invention preferably adopts an asymmetrical contour and an internal smooth transition surface (such as an ellipse) for the large groove set on the middle side, which enhances the control capability of the trailing edge region over the mainstream, optimizes the position of the airflow separation point, and further improves the overall aerodynamic efficiency; it solves the problem of weak trailing edge control capability and achieves the effect of enhancing aerodynamic efficiency.

[0098] Preferred embodiment of the small serration design in the outer region of the present invention (corresponding to) Figure 4 Within the outer functional area I, a first group of small sawtooth teeth is provided, preferably N1=5 in number. These sawtooth teeth are arranged at equal intervals radially. The geometric parameters are set according to the following proportional relationships: the cross-section of the small sawtooth is an isosceles triangle, the tooth height Ho is set to 2.0mm, the tooth width Wo is set to 4.0mm, satisfying H / W=0.5. The bottom chamfer radius Ro is set to 0.4mm, satisfying Ro / H=0.2. The smaller tooth height and specific chamfer design are intended to reduce shock wave drag under high-speed airflow while breaking up high-frequency turbulence.

[0099] In some implementations...

[0100] The tooth width of the first tooth 32 is Wi, which is greater than or equal to 5 mm and less than or equal to 8 mm; the radius of the bottom chamfer of the first tooth 32 is Ri, which is greater than or equal to 0.2 mm and less than or equal to 0.5 mm; the tooth height of the first tooth 32 is Hi, which is greater than or equal to 2.0 mm and less than or equal to 3.5 mm; and / or,

[0101] The tooth width of the second tooth 42 is Wi, which is greater than or equal to 5 mm and less than or equal to 8 mm. The radius of the bottom chamfer of the second tooth 42 is Ri, which is greater than or equal to 0.2 mm and less than or equal to 0.5 mm. The tooth height of the second tooth 42 is Hi, which is greater than or equal to 2.0 mm and less than or equal to 3.5 mm.

[0102] Preferably, the first tooth 32 and / or the second tooth 42 are isosceles triangles; and / or, the ratio of the tooth width of the first tooth 32 to the tooth width of the second tooth 42 is greater than or equal to 0.8 and less than or equal to 1.2; and / or, the ratio of the tooth height of the first tooth 32 to the tooth height of the second tooth 42 is greater than or equal to 0.8 and less than or equal to 1.2.

[0103] Preferred embodiment of the inner region serration design of the present invention (corresponding to) Figure 5 In the inner functional area II, a second set of small sawtooth teeth, numbered N2, is provided. N2 ≠ N1, and an extension section L2 can be provided between the small sawtooth teeth and the hub. In this embodiment, the number of small sawtooth teeth in this set is set to 7. The 7 small sawtooth teeth are also arranged at equal intervals along the radial direction of the blade trailing edge. The second set of small sawtooth teeth is designed with a radial distance between r1 and r2 (preferably 91mm to 129.5mm). The tooth width of both the first and second small sawtooth teeth is Wi, and can be set to 6.0mm (design range 5-8mm). The wider tooth width increases the turbulence area, which helps to generate a stronger turbulence breaking effect in the low-speed region. The bottom chamfer radius of both the first and second small sawtooth teeth is Ri, and can be set to 0.3mm (range 0.2-0.5mm). The smaller chamfer retains the sharpness of the tooth root, enhances the local shear force, and effectively suppresses the formation of low-speed vortices. Tooth height Hi: set to 3.0mm (design range 2.0-3.5mm). The higher tooth height provides stronger turbulence capability. The inner serration design suppresses vortex buildup in the low-speed zone near the hub, preventing low-frequency noise. The specific values ​​and parameters of the inner serrations are set to be the same as or different from the first set, depending on requirements. The cross-sections of both sets of serrations are preferably isosceles triangles, making the airflow smoother as it passes over the tooth tips, reducing local dead zones, improving airflow uniformity and stability, and avoiding additional friction losses caused by sharp chamfers; this solves the problem of large local flow losses and improves flow stability. The ratio of the tooth width of the first tooth 32 to the tooth width of the second tooth 42 is set to 0.8~1.2:1 (preferably 1:1), and the ratio of the tooth width of the first tooth 32 to the tooth height of the second tooth 42 is set to 0.8~1.2:1 (preferably 1:1) to ensure the formation of a high-frequency, fine turbulent structure, effectively suppressing high-frequency aerodynamic noise.

[0104] In some implementations...

[0105] In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, the ratio between the groove height of the third groove 51 and the tooth height of the first tooth 32 is greater than or equal to 8.5 and less than or equal to 14.0, the ratio between the groove height of the third groove 51 and the tooth height of the second tooth 42 is greater than or equal to 8.5 and less than or equal to 14.0, the ratio between the groove width of the third groove 51 and the tooth width of the first tooth 32 is greater than or equal to 7.5 and less than or equal to 12.5, and the ratio between the groove width of the third groove 51 and the tooth width of the second tooth 42 is greater than or equal to 7.5 and less than or equal to 12.5.

[0106] The large groove of this invention preferably adopts an asymmetrical composite curve profile (preferably a non-isosceles, non-circular structure) with a smooth transition surface inside. The ratio of the height of the large groove tooth to the height of the small sawtooth tooth is strictly limited to the range of 8.5 to 14.0, and the design of the width of the large groove tooth and the width of the small sawtooth tooth is limited to the range of 7.5 to 12.5, which can ensure that the air volume is not sacrificed when the large and small sawtooth teeth work together, while suppressing the generation of large-scale vortices.

[0107] In some implementations...

[0108] In the projection plane of a plane perpendicular to the axis of the axial flow fan blade: the innermost radial positions of the second teeth 42 of all blades 1 are located on the same circumference, which is a third circle whose center coincides with the center of the axial flow fan blade, and the radius of the third circle is r1; the outermost radial positions of the second teeth 42 of all blades 1 are located on the same circumference, which is a fourth circle whose center coincides with the center of the axial flow fan blade, and the radius of the fourth circle is r2; and r1 < r2, the distance from the second tooth 42 to the center of the axial flow fan blade is between r1 and r2; here, the minimum radius of r1 is the radius of the aforementioned ri when ρ=0 (ρ=(ri-Rhub) / L), and the maximum radius of r2 is the radius of the aforementioned ri when ρ=0.365 (ρ=(ri-Rhub) / L), where ρ∈[0,0.365];

[0109] The innermost radial position of the first tooth 32 of all blades 1 is located on the same circumference, which is the fifth circle, whose center coincides with the center of the axial flow blade, and the radius of the fifth circle is r3; the outermost radial position of the first tooth 32 of all blades 1 is located on the same circumference, which is the sixth circle, whose center coincides with the center of the axial flow blade, and the radius of the sixth circle is r4; and r3 < r4, the distance from the first tooth 32 to the center of the axial flow blade is between r3 and r4; here the minimum radius of r3 is the radius of ri when ρ=0.667 (ρ=(ri-Rhub) / L), and the maximum radius of r4 is the radius of ri when ρ=1 (ρ=(ri-Rhub) / L), where ρ∈[0.677,1].

[0110] This is the preferred structural form and distribution position of the first and second toothed structures of the present invention. Specifically, the second toothed structure is distributed in the region between the third and fourth circles, and the first toothed structure is distributed in the region between the fifth and sixth circles. This can further ensure that the high-frequency region located on the radially outer side can effectively handle the high-frequency turbulence generated by the high-speed airflow at the blade tip through the first tooth, breaking up the high-frequency small eddies there. In the low-frequency region located on the radially inner side, the distributed second tooth can effectively handle the low-frequency eddies generated by the low-speed airflow at the blade root, breaking up the low-frequency small eddies there. This further reduces airflow separation, reduces noise, increases airflow force, reduces energy consumption, and improves the energy efficiency of the wind turbine blade.

[0111] In some implementations...

[0112] In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, the groove height of the third groove 51 is H, and the groove width of the third groove 51 is W. The two satisfy the cubic function mathematical relationship: W=aH³+bH²+cH+d, where H∈[15,40]mm and W∈[30,70]mm. The allowable range of each coefficient is: a∈[0.000036,0.000044], b∈[-0.05192,-0.04248], c∈[1.9919,2.4345], d∈[0.4272,0.5222].

[0113] The geometric parameters of the large groove in this invention satisfy a specific mathematical function relationship, which can ensure that when the tooth height is increased to enhance the low-frequency vortex crushing capability, the tooth width increases nonlinearly and slowly, thereby avoiding excessive aerodynamic drag.

[0114] In this embodiment, the preferred curve relationship is: W = 0.00004H 3 -0.0472H 2 +2.2132H+0.4747, preferably W=49mm, H=27.5mm. The depth distribution curves of the serrations corresponding to different widths of the large groove in this embodiment are shown below. Figure 7 As shown, the inside of the teeth has a smooth transition surface (such as an elliptical outline). The shape of the large groove structure is preferably designed with equal depth from the center of the width to the depth of the serrations on both sides to optimize airflow separation. Alternatively, the width depth can be the largest in the middle, and the height of the serrations on both sides can be designed to be unequal.

[0115] See Figure 8 A comparison of simulated pressure maps of the wind turbine blade of this invention (right) and a conventional wind turbine blade (left) shows that the pressure gradient of this invention is smaller, and the red high-pressure area is also smaller. This indicates that, compared to the prior art, the high-pressure area of ​​the wind turbine blade of this invention is smaller, and the pressure distribution is more uniform. See also Figure 9A comparison of the simulated suction surface pressure diagrams of the wind turbine blade (right) of the present invention and the existing wind turbine blade (left) shows that the pressure gradient of the present invention is smaller, and the yellow high-pressure area is also smaller. This indicates that, compared with the prior art, the high-pressure area of ​​the suction surface of the wind turbine blade of the present invention is smaller, and the pressure distribution is more uniform.

[0116] The working principle and effect analysis of this invention are as follows: During operation, when the fan blades rotate, the airflow passes through the trailing edge. The small serrations on the outer and inner sides first divide the mainstream into several fine small vortices, interrupting the continuous large-scale vortex shedding process, thereby reducing high-frequency noise. Subsequently, the large groove on the middle side, with its special asymmetric structure and smooth curved surface, further guides and rectifyes the remaining mainstream, optimizing the airflow separation point and reducing pressure drag. This combined design strategy of "two sets of equidistant small serration arrays + independent large groove on the middle side" allows the fan blades to significantly reduce operating power while maintaining the original airflow, and at the same time, the noise level is significantly improved. Experimental data shows that compared with the traditional smooth trailing edge, this embodiment can reduce power by about 3W (about 10%) and reduce noise by 3-4 decibels under the same airflow. Figure 9-10 .

[0117] In order to verify the aerodynamic performance of the multi-stage sawtooth structure described in this invention, this embodiment uses computational fluid dynamics (CFD) software for numerical simulation. For example... Figure 8 and Figure 9 As shown, traditional structures have a large area of ​​strong low-pressure zone behind the trailing edge, and a large area of ​​high-pressure zone near the blade tip, resulting in significant pressure differential drag across the entire pressure surface. In the structure of this invention, due to the rectifying effect of the large groove in the middle section on the airflow and the control of the boundary layer by the small serrations, the high-pressure zone on the entire blade surface is significantly reduced. The surface pressure distribution from the leading edge to the trailing edge is very uniform, with a very small pressure difference. The pressure gradient at the trailing edge is gentle, without drastic abrupt changes, eliminating the noise source generated by large-scale vortices. This invention incorporates a large groove structure in the high-pressure zone at the trailing edge of the original blade, reducing the pressure in the middle region of the suction surface trailing edge, thus reducing the total pressure loss before and after the blade. While maintaining the same airflow, the simulated drive power decreases by approximately 3W, verifying the energy-saving effect of this invention. Simulation cloud diagrams visually demonstrate that this invention, through a specific multi-stage serration layout and differentiated parameter design, simultaneously achieves the dual objectives of vortex breaking noise reduction and power reduction at the physical mechanism level. Main principle: large vortex breaking in the middle, small vortex breaking on both sides.

[0118] To further verify the actual effect, a prototype of the invented wind turbine blade was made and tested. The experimental test data compared with existing wind turbine blades are shown in Table 1 below. The power curve of the experimental test data is shown in the figure below. Figure 9 See noise curve Figure 10Compared with existing fan blades, the fan blades of this invention reduce power by about 3W (approximately 9%~11%) under the same airflow, and reduce noise by 3~4 decibels under the same airflow. The experiment further verifies the effectiveness of the proposed solution. By designing multiple non-equidistant serrations and trailing edge bending, the power of the fan can be reduced while maintaining the same airflow, and the noise from the rotating vortex of the fan blades can also be reduced.

[0119] Table 1

[0120]

[0121] Alternative embodiment of the invention 1: Small serrated shape variant

[0122] While maintaining the "5+7+1" (5 first grooves + 7 second grooves + 1 third groove) layout, the cross-sectional shape of the small serrations can be replaced from a "beveled isosceles triangle" to a "rectangle with rounded corners" or a "semi-circle". This variant is suitable for scenarios with extremely high manufacturing process requirements or where further reduction of high-frequency howling is needed. Although the noise reduction mechanism is slightly different, it can still achieve the effect of breaking up vortices. Transition sections L1 and L2 can be omitted between the outer small serrations and the blade tip, and between the inner small serrations and the hub. Setting transition sections can reduce some vortex leakage at the junction of the outer end and the inner end, but the absence of transition sections or only one transition section will not significantly affect the actual effect of the invention.

[0123] Alternative Example 2: Large Groove Array

[0124] The single large groove on the middle side is replaced with a "micro-array" composed of 3-5 small serrations, which also feature a rounded transition design. This design can further refine the modulation effect on the main shear layer and is suitable for ultra-high power fans or special environments with extremely high noise requirements.

[0125] The present invention also provides an axial flow fan, which includes the aforementioned axial flow fan blades.

[0126] This invention provides a multi-stage sawtooth structure that can be differentiated according to the radial position characteristics of the fan blades. The radial distribution of the axial fan blade trailing edge adopts a three-stage differentiated design scheme of "outer-middle-inner", which can achieve significant noise reduction and energy saving without sacrificing airflow.

[0127] The technical problem solved by this invention:

[0128] The present invention aims to solve the technical problems of high power loss and high operating noise caused by large-scale vortices generated by trailing edge airflow separation when existing axial flow fan blades operate at high air volume.

[0129] The beneficial effects of this invention are:

[0130] 1. This invention solves the problem of uneven airflow separation, achieving synergistic noise reduction and energy saving. By setting small serrations on the outer and inner sides of the fan blade trailing edge and a large groove in the middle, and using specific geometric parameters, multi-level disturbances are created in the airflow at different radial positions. This non-uniform distribution effectively suppresses the generation of large-scale vortices and disperses energy dissipation, thereby significantly reducing operating power at the same airflow. Experimental tests have verified that this reduces air conditioner power by approximately 3W (about 10%) at the same airflow, while also effectively reducing air conditioner noise by 3-4 decibels.

[0131] 2. It solves the problem of large local flow losses, achieving the effect of improving flow stability. The small sawtooth adopts an isosceles triangular structure with a bottom chamfer design, which makes the airflow smoother when passing through the tooth tip, reduces local dead zones, improves the uniformity and stability of the airflow, and avoids additional friction losses caused by sharp chamfers.

[0132] 3. The problem of weak trailing edge control capability has been solved, achieving the effect of enhanced aerodynamic efficiency. The large groove set on the middle side adopts an asymmetrical compound curve profile (preferably a special profile that is not isosceles triangle or non-circular) and a smooth transition surface inside (such as an ellipse), which enhances the control capability of the trailing edge region over the mainstream, optimizes the position of the airflow separation point, and further improves the overall aerodynamic efficiency.

[0133] The present invention also provides an air conditioner that includes the aforementioned axial flow fan.

[0134] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. An axial flow fan blade, characterized in that: include: At least two spaced-apart blades (1), each blade (1) comprising a leading edge (11) and a trailing edge (12), the leading edge (11) being located on the windward side of the blade (1), and the trailing edge (12) being located on the leeward side of the blade (1). The trailing edge (12) is provided with a first tooth structure (3), a second tooth structure (4) and a groove structure (5). The groove structure (5) is located between the first tooth structure (3) and the second tooth structure (4). The first tooth structure (3) includes at least one first groove (31), the second tooth structure (4) includes at least one second groove (41), and the groove structure (5) includes at least one third groove (51). In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, the area of ​​a single groove of the first groove (31) is smaller than the area of ​​a single groove of the third groove (51), and the area of ​​a single groove of the second groove (41) is smaller than the area of ​​a single groove of the third groove (51).

2. The axial flow fan blade according to claim 1, characterized in that: The first tooth structure (3) includes at least one first tooth (32), which is connected to the first groove (31). The second tooth structure (4) includes at least one second tooth (42), which is connected to the second groove (41). The third groove (51) is at least one, with one end connected to the first tooth (32) and the other end connected to the second tooth (42). In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, along the radial direction of the axial flow fan blade, the first tooth (32) is connected to the radial outer side of the third groove (51), and the second tooth (42) is connected to the radial inner side of the third groove (51).

3. The axial flow fan blade according to claim 1, characterized in that: It also includes a hub (2), the blades (1) are disposed on the outer periphery of the hub (2), and at least two blades (1) are spaced apart along the circumferential direction of the hub (2); In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, along the radial direction of the axial flow fan blade, the outermost radial ends of all the blades (1) are located on the same circumference, which is the first circle, whose center coincides with the center of the axial flow fan blade, and the radius of the first circle is R; the outermost radial ends of the hub (2) are located on the same circumference, which is the second circle, whose center coincides with the center of the axial flow fan blade, and the radius of the second circle is Rhub; In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, the distance between the position on the trailing edge (12) and the center of the axial flow fan blade is ri. Along the radial extension direction from the inside to the outside on the trailing edge (12), the effective working radius L = R - Rhub is defined, and the normalized coordinate parameter ρ = (ri - Rhub) / L is introduced to divide the trailing edge (12) into three functional areas: Outer functional area I: corresponding to dimensionless normalized coordinate parameter ρ∈[0.677,1], set the first tooth-shaped structure (3); Inner functional area II: corresponding to the dimensionless normalized coordinate parameter ρ∈[0,0.365], the second tooth-shaped structure (4) is set; Intermediate control area III: corresponding to the dimensionless normalized coordinate parameter ρ∈[0.365,0.677], the groove structure (5) is set; The value of ρ is in the range of [0, 1].

4. The axial flow fan blade according to claim 3, characterized in that: The third groove (51) has a groove center, the first tooth structure (3) and the second tooth structure (4) are asymmetrically arranged with respect to the groove center, along the radial direction from the inside to the outside, the effective working radius of the first circle is L, and the minimum distance from the groove center to the hub (2) is greater than or equal to 40%L and less than or equal to 60%L.

5. The axial flow fan blade according to claim 2, characterized in that: In the first tooth structure (3), a plurality of first teeth (32) are equidistantly distributed along the radial direction; in the second tooth structure (4), a plurality of second teeth (42) are equidistantly distributed along the radial direction, and the number of second teeth (42) is different from the number of first teeth (32).

6. The axial flow fan blade according to claim 2, characterized in that: In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, the ratio of the tooth height to the tooth width of the first tooth (32) is greater than or equal to 0.5 and less than or equal to 0.8, and the ratio of the chamfer radius at the bottom of the first tooth (32) to the tooth height of the first tooth (32) is greater than or equal to 0.1 and less than or equal to 0.2; and / or, the ratio of the tooth height to the tooth width of the second tooth (42) is greater than or equal to 0.5 and less than or equal to 0.8, and the ratio of the chamfer radius at the bottom of the second tooth (42) to the tooth height of the second tooth (42) is greater than or equal to 0.1 and less than or equal to 0.2; And / or, in the projection plane of the plane perpendicular to the axis of the axial fan blade, the inner wall of the third groove (51) is a smooth curved surface.

7. The axial flow fan blade according to claim 2, characterized in that: The tooth width of the first tooth (32) is Wi, which is greater than or equal to 5 mm and less than or equal to 8 mm; the radius of the bottom chamfer of the first tooth (32) is Ri, which is greater than or equal to 0.2 mm and less than or equal to 0.5 mm; the tooth height of the first tooth (32) is Hi, which is greater than or equal to 2.0 mm and less than or equal to 3.5 mm; and / or, The tooth width of the second tooth (42) is Wi, which is greater than or equal to 5 mm and less than or equal to 8 mm. The radius of the bottom chamfer of the second tooth (42) is Ri, which is greater than or equal to 0.2 mm and less than or equal to 0.5 mm. The tooth height of the second tooth (42) is Hi, which is greater than or equal to 2.0 mm and less than or equal to 3.5 mm.

8. The axial flow fan blade according to claim 2, characterized in that: The first tooth (32) and / or the second tooth (42) are isosceles triangles; and / or, The ratio of the tooth width of the first tooth (32) to the tooth width of the second tooth (42) is greater than or equal to 0.8 and less than or equal to 1.2; and / or the ratio of the tooth height of the first tooth (32) to the tooth height of the second tooth (42) is greater than or equal to 0.8 and less than or equal to 1.

2.

9. The axial flow fan blade according to claim 2, characterized in that: In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, the ratio between the groove height of the third groove (51) and the tooth height of the first tooth (32) is greater than or equal to 8.5 and less than or equal to 14.0, the ratio between the groove height of the third groove (51) and the tooth height of the second tooth (42) is greater than or equal to 8.5 and less than or equal to 14.0, the ratio between the groove width of the third groove (51) and the tooth width of the first tooth (32) is greater than or equal to 7.5 and less than or equal to 12.5, and the ratio between the groove width of the third groove (51) and the tooth width of the second tooth (42) is greater than or equal to 7.5 and less than or equal to 12.

5.

10. The axial flow fan blade according to claim 2, characterized in that: In the projection plane of a plane perpendicular to the axis of the axial flow fan blade: the innermost radial positions of the second teeth (42) of all the blades are located on the same circumference, which is a third circle whose center coincides with the center of the axial flow fan blade, and the radius of the third circle is r1; the outermost radial positions of the second teeth (42) of all the blades are located on the same circumference, which is a fourth circle whose center coincides with the center of the axial flow fan blade, and the radius of the fourth circle is r2; and r1 < r2, the distance from the second tooth (42) to the center of the axial flow fan blade is greater than or equal to r1 and less than or equal to r2; The innermost radial position of the first tooth (32) of all the blades is located on the same circumference, which is the fifth circle, whose center coincides with the center of the axial flow blade, and the radius of the fifth circle is r3; the outermost radial position of the first tooth (32) of all the blades is located on the same circumference, which is the sixth circle, whose center coincides with the center of the axial flow blade, and the radius of the sixth circle is r4; and r3 < r4, the distance from the first tooth (32) to the center of the axial flow blade is greater than or equal to r3 and less than or equal to r4.

11. The axial flow fan blade according to claim 1, characterized in that: In the projection plane of the plane perpendicular to the axis of the axial flow fan blade, the groove height of the third groove (51) is H, and the groove width of the third groove (51) is W. The two satisfy the cubic function mathematical relationship: W=aH³+bH²+cH+d, where H∈[15,40]mm, W∈[30,70]mm; the range of each coefficient is: a∈[0.000036,0.000044], b∈[-0.05192,-0.04248], c∈[1.9919,2.4345], d∈[0.4272,0.5222].

12. An axial flow fan, characterized in that: Includes the axial flow fan blades according to any one of claims 1-11.

13. An air conditioner, characterized in that: Including the axial flow fan as described in claim 12.

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