Blade for fan, axial flow fan and air handling equipment

Abstract

The present invention discloses a blade for a fan, an axial flow fan and an air treatment device, which relates to the technical field of fans and solves the problem of generating a lot of noise when the fan blade rotates in the prior art. The present invention is used for the blade of the fan, and the suction surface of the blade body is provided with a streamlined flow guide and noise reduction component, and the streamlined flow guide and noise reduction component includes a streamlined flow guide structure and a flow guide and noise reduction structure, and the flow guide profile of the streamlined flow guide structure is consistent with the blade profile of the streamlined flow guide and noise reduction component at the position of the blade body; the flow guide and noise reduction structure is arranged at the trailing edge of the blade body, and the profile of the flow guide and noise reduction structure is consistent with the blade profile of the streamlined flow guide and noise reduction component at the position of the blade body. The present invention is used for the blade of the fan, and the development of the shedding vortex of the fan blade can be suppressed by the streamlined flow guide and noise reduction component, thereby reducing the flow kinetic energy loss and reducing the fan noise; it can also improve the uniformity of the fan flow field and improve the fan efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of fans, and in particular to a blade for a fan, an axial flow fan comprising the blade, and air handling equipment comprising the axial flow fan. Background Art

[0002] Axial fans are widely used in various air handling equipment. Their working efficiency and various performances have an important impact on the energy efficiency and user comfort of air handling equipment. Low efficiency of axial fans will increase the energy consumption of air handling equipment, while high noise of axial fans will affect the user comfort of air handling equipment. Therefore, improving the energy efficiency of axial fans and reducing the noise of axial fans are of practical significance to the product.

[0003] According to boundary layer theory, vortex detachment will occur on the surface of the wind blade, which is particularly obvious at the outer edge and trailing edge of the blade; and vortex detachment will cause random lift pulsation and interfere with the radial airflow, which can easily generate broadband vortex noise and affect the performance of the wind blade. Figure 1 The schematic diagram of the existing axial flow fan is shown. In the existing axial flow fans, the trailing edge of the blades mostly adopts a flush type, an overall convex type, or an overall concave type structure. When the blades of this structure rotate, the outer edge and the trailing edge of the blades generate strong periodic shedding vortices, which increases the flow kinetic energy loss and generates a lot of noise. Summary of the invention

[0004] One of the purposes of the present invention is to provide a blade for a fan, an axial flow fan and an air handling device, which solves the technical problem in the prior art that when the fan blade rotates, the outer edge and the trailing edge of the blade generate strong periodic shedding vortices, increase the flow kinetic energy loss, and generate a lot of noise. The many technical effects that can be produced by the preferred technical solution of the present invention are described in detail below.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention is used for a blade of a fan, comprising a blade body, a suction surface of the blade body being provided with a streamlined flow guide and noise reduction component, the streamlined flow guide and noise reduction component comprising a streamlined flow guide structure and a flow guide and noise reduction structure, wherein the flow guide profile of the streamlined flow guide structure is consistent with the blade profile of the streamlined flow guide and noise reduction component at the position of the blade body; the flow guide and noise reduction structure is arranged at the trailing edge of the blade body, and the profile of the flow guide and noise reduction structure is consistent with the blade profile of the streamlined flow guide and noise reduction component at the position of the blade body.

[0007] According to a preferred embodiment, the number of the streamlined flow guide and noise reduction components is multiple groups, and the multiple groups of the streamlined flow guide and noise reduction components are arranged at intervals.

[0008] According to a preferred embodiment, the spacing distances between two adjacent groups of the streamlined flow guide and noise reduction components are the same and / or different, and at least 50% of the streamlined flow guide and noise reduction components are distributed in an annular area of ​​0.7D to 1D, where D is the fan diameter.

[0009] According to a preferred embodiment, the streamlined flow-guiding structure is a flow-guiding rib or a flow-guiding groove, and the flow-guiding rib is a structure protruding from the surface of the blade body, and the flow-guiding groove is a structure recessed in the surface of the blade body.

[0010] According to a preferred embodiment, the guide line length of the streamlined guide structure is 0.3D1~1D1, and the tail of the streamlined guide structure intersects with the trailing edge of the blade body, wherein D1 is the blade arc length of the streamlined guide noise reduction component at the blade body position.

[0011] According to a preferred embodiment, the profile length of the flow guide and noise reduction structure is 0.05D1~0.2D1, and the tail of the flow guide and noise reduction structure intersects with the trailing edge of the blade body, wherein D1 is the blade arc length of the streamlined flow guide and noise reduction component at the blade body position.

[0012] According to a preferred embodiment, the flow guide and noise reduction structure is a fin-type flow guide, and the height of the fin-type flow guide protruding from the surface of the blade body gradually increases from the line head to the line tail.

[0013] According to a preferred embodiment, the angle between the end surface of the flow-guiding and noise-reducing structure located at the end of the wire and the bottom surface of the flow-guiding and noise-reducing structure is 100° to 150°.

[0014] The axial flow fan of the present invention comprises blades and a hub, wherein the blades are blades for a fan as described in any one of the technical solutions of the present invention, the number of the blades is multiple, and the blades are fixedly connected to the hub.

[0015] The air handling equipment of the present invention comprises the axial flow fan described in any one of the technical solutions of the present invention.

[0016] The blade for the fan, the axial flow fan and the air handling equipment provided by the present invention have at least the following beneficial technical effects:

[0017] The present invention is used for the blade of the fan, and a streamlined flow-guiding noise reduction component is arranged on the suction surface of the blade body, and the streamlined flow-guiding noise reduction component includes a streamlined flow-guiding structure and a flow-guiding noise reduction structure. The flow-guiding profile of the streamlined flow-guiding structure is consistent with the blade profile of the streamlined flow-guiding noise reduction component at the position of the blade body. Through the action of the streamlined flow-guiding structure, the boundary layer vortex can be suppressed from developing into a shedding vortex; the flow-guiding noise reduction structure is arranged at the trailing edge of the blade body, and the profile of the flow-guiding noise reduction structure is consistent with the blade profile of the streamlined flow-guiding noise reduction component at the position of the blade body. Through the action of the flow-guiding noise reduction structure, the development of the shedding vortex at the trailing edge of the blade body can be further suppressed. That is, the present invention is used for the blade of the fan, and through the action of the streamlined flow-guiding noise reduction component, the development of the shedding vortex of the fan blade can be suppressed, thereby reducing the flow kinetic energy loss and reducing the fan noise; it can also improve the uniformity of the fan flow field and improve the fan efficiency.

[0018] The axial flow fan of the present invention includes any one of the technical solutions of the present invention for the fan blades. By using any one of the technical solutions of the present invention for the fan blades, the development of the fan blade shedding vortex can be suppressed, thereby reducing the flow kinetic energy loss and the fan noise; the uniformity of the fan flow field can also be improved, and the fan efficiency can be improved. That is, the axial flow fan of the present invention has the advantages of low noise and high fan efficiency.

[0019] The air handling equipment of the present invention includes an axial flow fan of any technical solution in the present invention. Since the axial flow fan has the advantages of low noise and high fan efficiency, the performance of the air handling equipment can be improved by using the axial flow fan of any technical solution in the present invention.

[0020] That is, the present invention is used for fan blades, axial flow fans and air handling equipment, solving the technical problem in the prior art that when the fan blades rotate, the outer edge and the trailing edge of the blades generate strong periodic shedding vortices, which increases the flow kinetic energy loss and generates a lot of noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 is a schematic diagram of an existing axial flow fan;

[0023] Figure 2 is a first schematic diagram of a preferred embodiment of an axial flow fan of the present invention;

[0024] Figure 3is a second schematic diagram of a preferred embodiment of the axial flow fan of the present invention;

[0025] Figure 4 It is a schematic diagram of a preferred embodiment of the blade of the present invention;

[0026] Figure 5 It is a schematic diagram of the distribution of the streamlined flow-guiding structure of the present invention on the blade body;

[0027] Figure 6 It is a schematic diagram of the profile of a preferred embodiment of the streamlined flow-guiding structure of the present invention;

[0028] Figure 7 is a first cross-sectional view of a preferred embodiment of an axial flow fan of the present invention;

[0029] Figure 8 yes Figure 7 A magnified view of part I1;

[0030] Fig. 9 yes Figure 8 AA section diagram in;

[0031] Fig.10 It is a schematic diagram of the profile of a preferred embodiment of the flow guide and noise reduction structure of the present invention;

[0032] Fig.11 is a second cross-sectional view of a preferred embodiment of the axial flow fan of the present invention;

[0033] Fig.12 yes Fig.11 A magnified view of part I2;

[0034] Fig.13 yes Fig.12 AA section diagram in;

[0035] Fig.14 yes Fig.12 BB cross-section diagram in;

[0036] Fig.15 yes Fig.12 Schematic diagram of CC cross section;

[0037] Fig.16 It is the pressure cloud diagram at the trailing edge of the existing blade;

[0038] Fig.17 It is a pressure cloud diagram at the trailing edge of the blade of the present invention.

[0039] In the figure: 1. blade; 11. blade body; 12. streamlined guide structure; 121. first profile line; 122. first streamlined arc; 123. second streamlined arc; 13. guide noise reduction structure; 131. second profile line; α: angle; 2. hub. DETAILED DESCRIPTION

[0040] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0041] The following is attached to the instruction manual Figures 2 to 17 And embodiments 1 to 3 describe in detail the blades for the fan, the axial flow fan and the air handling equipment of the present invention.

[0042] Example 1

[0043] This embodiment describes in detail the blades used for a fan of the present invention.

[0044] The blade of the fan in this embodiment includes a blade body 11, and the suction surface of the blade body 11 is provided with a streamlined flow guide and noise reduction component, such as Figures 2 to 4 Preferably, the streamlined flow guide and noise reduction component includes a streamlined flow guide structure 12 and a flow guide and noise reduction structure 13, wherein the flow guide profile of the streamlined flow guide structure 12 is consistent with the blade profile of the streamlined flow guide and noise reduction component at the position of the blade body 11; the flow guide and noise reduction structure 13 is arranged at the trailing edge of the blade body 11, and the profile of the flow guide and noise reduction structure 13 is consistent with the blade profile of the streamlined flow guide and noise reduction component at the position of the blade body 11, as shown in FIG. Figure 3 or Figure 4 As shown. Figure 3 or Figure 4 As shown, the streamlined flow guide and noise reduction assembly is arranged along the radial direction of the blade body 11.

[0045] This embodiment is used for the blade of the fan, and a streamlined flow guide and noise reduction component is arranged on the suction surface of the blade body 11, and the streamlined flow guide and noise reduction component includes a streamlined flow guide structure 12 and a flow guide and noise reduction structure 13, and the flow guide profile of the streamlined flow guide structure 12 is consistent with the blade profile of the streamlined flow guide and noise reduction component at the position of the blade body 11, and the boundary layer vortex can be suppressed from developing into a shedding vortex through the action of the streamlined flow guide structure 12; the flow guide and noise reduction structure 13 is arranged at the trailing edge of the blade body 11, and the profile of the flow guide and noise reduction structure 13 is consistent with the blade profile of the streamlined flow guide and noise reduction component at the position of the blade body 11, and the development of the shedding vortex at the trailing edge of the blade body 11 can be further suppressed through the action of the flow guide and noise reduction structure 13. That is, this embodiment is used for the blade of the fan, and through the action of the streamlined flow guide and noise reduction component, the development of the shedding vortex of the fan blade can be suppressed, thereby reducing the flow kinetic energy loss and reducing the fan noise; and the uniformity of the fan flow field can be improved, and the fan efficiency can be improved. That is, this embodiment is used for the blades of the fan, which solves the technical problem in the prior art that when the fan blades rotate, the outer edge and the trailing edge of the blades generate strong periodic shedding vortices, which increases the flow kinetic energy loss and generates a lot of noise.

[0046] The trailing edge and outer edge of the blade body 11 are the key locations for vortex shedding. In this embodiment, the flow guide and noise reduction structure 13 is provided at the trailing edge of the blade body 11 to further suppress the development of vortex shedding at the trailing edge of the blade body 11. From the comparison of simulation results, it is found that the low pressure level at the trailing edge of the blade of this embodiment is improved compared with the blade in the prior art. Specifically, Fig.16 and Fig.17 As shown, before the improvement, the low-pressure area at the trailing edge of the blade was wide and the low pressure was obvious, with the low pressure values ​​mainly distributed in [-112.0Pa, -69.5Pa]; while after the improvement, the low-pressure range of the wind blade was significantly narrowed, with the low pressure values ​​mainly distributed in [-69.5Pa, -37.6Pa], indicating that the development of the shed vortex at the trailing edge of the blade was significantly suppressed.

[0047] According to a preferred embodiment, the number of streamlined flow guide and noise reduction components is multiple groups, and the multiple groups of streamlined flow guide and noise reduction components are arranged at intervals, such as Figure 3 or Figure 4 As shown. Figure 3 or Figure 4 As shown, seven groups of streamlined flow guide and noise reduction components are arranged on the blade body 11. The number of streamlined flow guide and noise reduction components can be determined according to the size of the fan. Specifically, when the diameter of the fan is less than 300mm, the number of streamlined flow guide and noise reduction components is generally set to 3 to 5 groups; when the diameter of the fan is more than 300mm, the number of streamlined flow guide and noise reduction components is generally set to 5 to 9 groups. The preferred technical solution of this embodiment determines the number of streamlined flow guide and noise reduction components based on the size of the fan, so that the number of streamlined flow guide and noise reduction components matches the size of the fan, thereby improving the noise reduction effect of the streamlined flow guide and noise reduction components.

[0048] According to a preferred embodiment, the intervals between two adjacent groups of streamlined flow guide and noise reduction components are the same and / or different, and at least 50% of the streamlined flow guide and noise reduction components are distributed in an annular area of ​​0.7D to 1D, where D is the fan diameter. Figure 5 As shown. Figure 5 or Figure 6 As shown, seven groups of streamlined flow guide and noise reduction components are arranged on the blade body 11. Among the seven groups of streamlined flow guide and noise reduction components, two adjacent groups of streamlined flow guide and noise reduction components can have a variety of spacing distances, so that the streamlined flow guide and noise reduction components are distributed at non-equidistant intervals. Two adjacent groups of streamlined flow guide and noise reduction components can also have only one spacing distance, so that the streamlined flow guide and noise reduction components are distributed at an equal spacing. Since the strength of the wake shedding vortex from the trailing edge root to the trailing edge blade tip of the blade body 11 is different, in the range of 0.7D to 1D (such as Figure 5 The trailing edge vortex shedding intensity is the strongest within the annular area of ​​0.7D to 1D. The preferred technical solution of this embodiment can effectively suppress the vortex shedding at the trailing edge of the blade body 11 by distributing most of the streamlined flow guide and noise reduction components in the annular area of ​​0.7D to 1D.

[0049] According to a preferred embodiment, the streamlined flow guiding structure 12 is a flow guiding rib or a flow guiding groove. Preferably, the flow guiding rib is a structure protruding from the surface of the blade body 11, and the flow guiding groove is a structure recessed in the surface of the blade body 11. Figures 7 to 9 1 shows a schematic diagram of the structure of the streamlined guide structure 12 as a guide rib. More preferably, the AA section of the streamlined guide structure 12 has a first streamlined arc 122 and a second streamlined arc 123, and the first streamlined arc 122 and the second streamlined arc 123 are streamlined, such as Figures 7 to 9 As shown. The height H1 of the first streamlined arc 122 and the length L1 of the second streamlined arc 123 are determined based on the size of the fan. Specifically, the larger the fan size, the larger H1 and L1; the smaller the fan size, the smaller H1 and L1. More preferably, the streamlined guide structure 12 is formed by linear scanning along the streamlined guide structure 12, and then undergoing streamline processing such as chamfering. The first streamlined arc 122 and the second streamlined arc 123 of the streamlined guide structure 12 of the preferred technical solution of this embodiment are streamlined structures, which can effectively suppress the development of boundary layer shedding vortices of the blade body 11.

[0050] According to a preferred embodiment, the length of the guide line of the streamlined guide structure 12 is 0.3D1 to 1D1, and the tail of the streamlined guide structure 12 intersects with the trailing edge of the blade body 11, wherein D1 is the blade arc length of the streamlined guide noise reduction component at the position of the blade body 11. The tail of the line refers to the end close to the trailing edge of the blade body 11. Specifically, the guide line of the streamlined guide structure 12 is Figure 6The first profile line 121 shown. Preferably, the length of the guide profile line of the streamlined guide structure 12 is also determined based on the size of the fan. Specifically, the larger the size of the fan, the longer the guide profile line of the streamlined guide structure 12; the smaller the size of the fan, the shorter the guide profile line of the streamlined guide structure 12. The preferred technical solution of this embodiment has a guide profile line length of 0.3D1 to 1D1, and the tail of the streamlined guide structure 12 intersects with the trailing edge of the blade body 11, which can effectively inhibit the development of the shedding vortex of the boundary layer of the blade body 11, especially the development of the shedding vortex at the trailing edge of the blade body.

[0051] According to a preferred embodiment, the profile length of the flow guide and noise reduction structure 13 is 0.05D1 to 0.2D1, and the tail of the flow guide and noise reduction structure 13 intersects with the trailing edge of the blade body 11, wherein D1 is the blade arc length of the streamlined flow guide and noise reduction component at the position of the blade body 11. The tail of the line refers to the end close to the trailing edge of the blade body 11. Specifically, the profile of the flow guide and noise reduction structure 13 is Fig.10 The second profile line 131 shown. Preferably, the profile line length of the flow guide and noise reduction structure 13 is also determined based on the size of the fan. Specifically, the larger the size of the fan, the longer the profile line length of the flow guide and noise reduction structure 13; the smaller the size of the fan, the shorter the profile line length of the flow guide and noise reduction structure 13. The preferred technical solution of this embodiment has a profile line length of 0.05D1 to 0.2D1, and the tail of the flow guide and noise reduction structure 13 is made to intersect with the trailing edge of the blade body 11, which can effectively inhibit the development of the shedding vortex of the boundary layer of the blade body 11, especially the development of the shedding vortex at the trailing edge of the blade body.

[0052] According to a preferred embodiment, the flow guide and noise reduction structure 13 is a fish fin type flow guide. Fig.11 or Fig.12 Preferably, the height of the fish fin type deflector protruding from the surface of the blade body 11 gradually increases from the line head to the line tail, as shown in FIG. Fig.11 or Fig.12 The line head refers to the end close to the leading edge of the blade body 11, and the line tail refers to the end close to the trailing edge of the blade body 11. More preferably, the angle α between the end surface of the flow guide and noise reduction structure 13 at the line tail and the bottom surface of the flow guide and noise reduction structure 13 is 100° to 150°, as shown in FIG. Fig.14 As shown. The fin-shaped deflector of the preferred technical solution of this embodiment is a deflection structure similar to a fin. Figures 13-15As shown, the width W2 and height H2 of the AA section of the fish-fin-type deflector, the length L2 and height H2 of the BB section, and the width W2 of the CC section are determined based on the size of the fan. Specifically, the larger the fan size, the larger W2, H2 and L2; the smaller the fan size, the smaller W2, H2 and L2. More preferably, the flow-guiding and noise-reducing structure 13 is initially formed by scanning the profile of the flow-guiding and noise-reducing structure 13 along the AA section, and then the flow-guiding and noise-reducing structure 13 is formed into a fish-fin-type deflector through chamfering and streamline processing, and the flow-guiding and noise-reducing structure 13 is closely integrated with the streamlined flow-guiding structure 12. The flow-guiding and noise-reducing structure 13 of the preferred technical solution of this embodiment is a fish-fin-type deflector, and the angle α between the end face of the flow-guiding and noise-reducing structure 13 located at the end of the line and the bottom face of the flow-guiding and noise-reducing structure 13 is 100° to 150°, which can effectively suppress the development of the shedding vortex at the trailing edge of the blade body 11.

[0053] Example 2

[0054] This embodiment describes the axial flow fan of the present invention in detail.

[0055] The axial flow fan of this embodiment includes blades 1 and a hub 2. Figure 2 or Figure 3 Preferably, the blade 1 is a blade used for a fan according to any one of the technical solutions in Example 1, the number of blades 1 is multiple, and the blade 1 is fixedly connected to the hub 2, as shown in FIG. Figure 2 or Figure 3 Preferably, the structure of the hub 2 may be the same as that of the prior art, and will not be described in detail herein.

[0056] The axial flow fan of this embodiment includes any one of the technical solutions in Example 1 for the fan blades. By using any one of the technical solutions in Example 1 for the fan blades, the development of the fan blade shedding vortex can be suppressed, thereby reducing the flow kinetic energy loss and the fan noise; the uniformity of the fan flow field can also be improved, and the fan efficiency can be improved. That is, the axial flow fan of this embodiment has the advantages of low noise and high fan efficiency, and solves the technical problem in the prior art that when the fan blade rotates, the outer edge and the trailing edge of the blade generate strong periodic shedding vortices, increase the flow kinetic energy loss, and generate a lot of noise.

[0057] Example 3

[0058] This embodiment describes the air treatment equipment of the present invention in detail.

[0059] The air handling device of this embodiment includes the axial flow fan of any one of the technical solutions in Embodiment 2. The remaining structure of the air handling device of this embodiment may be the same as the prior art, and will not be described in detail here. Preferably, the air handling device of this embodiment is, for example, a fan.

[0060] The air handling device of this embodiment includes an axial flow fan of any technical solution in Embodiment 2. Since the axial flow fan of any technical solution in Embodiment 2 can suppress the development of the shedding vortex of the fan blade, it can reduce the flow kinetic energy loss and reduce the fan noise; it can also improve the uniformity of the fan flow field and improve the fan efficiency, so the performance of the air handling device can be improved by the axial flow fan of any technical solution in this embodiment. That is, the air handling device of this embodiment solves the technical problem in the prior art that when the fan blade rotates, the outer edge and the trailing edge of the blade generate strong periodic shedding vortexes, increase the flow kinetic energy loss, and generate a lot of noise.

[0061] In the description of the present invention, it should be noted that, unless otherwise specified, "multiple" means two or more than two; the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0062] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0063] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A blade for a fan, characterized in that: The invention comprises a blade body (11), wherein a streamlined flow-guiding and noise-reducing component is provided on a suction surface of the blade body (11), wherein the streamlined flow-guiding and noise-reducing component comprises a streamlined flow-guiding structure (12) and a flow-guiding and noise-reducing structure (13) provided at an upper end of the streamlined flow-guiding structure (12), wherein: The flow-guiding profile of the streamlined flow-guiding structure (12) is consistent with the blade profile of the streamlined flow-guiding noise reduction component at the position of the blade body (11); the flow-guiding noise reduction structure (13) is arranged at the trailing edge of the blade body (11), and the profile of the flow-guiding noise reduction structure (13) is consistent with the blade profile of the streamlined flow-guiding noise reduction component at the position of the blade body (11); The number of the streamlined flow guide and noise reduction components is multiple groups, and the multiple groups of streamlined flow guide and noise reduction components are arranged at intervals; The spacing distances between two adjacent groups of the streamlined flow guide and noise reduction components are the same or different, and at least 50% of the streamlined flow guide and noise reduction components are distributed in an annular area of ​​0.7D~1D, where D is the fan diameter.

2. The blade for a fan according to claim 1, characterized in that: The streamlined flow-guiding structure (12) is a flow-guiding rib or a flow-guiding groove, and the flow-guiding rib is a structure protruding from the surface of the blade body (11), and the flow-guiding groove is a structure recessed in the surface of the blade body (11).

3. The blade for a fan according to claim 1, characterized in that: The flow-guiding line length of the streamlined flow-guiding structure (12) is 0.3D1-1D1, and the tail of the streamlined flow-guiding structure (12) intersects with the trailing edge of the blade body (11), wherein D1 is the blade arc length of the streamlined flow-guiding noise reduction component at the position of the blade body (11).

4. The blade for a fan according to claim 1, characterized in that: The profile length of the flow guide and noise reduction structure (13) is 0.05D1-0.2D1, and the tail of the line of the flow guide and noise reduction structure (13) intersects with the trailing edge of the blade body (11), wherein D1 is the blade arc length of the streamlined flow guide and noise reduction component at the position of the blade body (11).

5. The blade for a fan according to claim 1, characterized in that: The flow guide and noise reduction structure (13) is a fin-type flow guide, and the height of the fin-type flow guide protruding from the surface of the blade body (11) gradually increases from the line head to the line tail.

6. The blade for a fan according to claim 5, characterized in that: The angle (α) between the end surface of the flow guiding and noise reduction structure (13) located at the end of the wire and the bottom surface of the flow guiding and noise reduction structure (13) is 100° to 150°.

7. An axial flow fan, characterized in that: The invention comprises a blade (1) and a hub (2), wherein the blade (1) is a blade for a wind turbine as claimed in any one of claims 1 to 6, there are a plurality of blades (1), and the blade (1) is fixedly connected to the hub (2).

8. An air treatment device, characterized in that: Including the axial flow fan as described in claim 7.

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