Axial flow fan blade and axial flow fan
By setting an elliptical annular tail on the tail edge of the axial flow blade, the problem that the axial flow blade in the prior art cannot take into account both noise reduction and air volume, and better noise control and air volume increase are achieved.
Patent Information
- Application Number
- CN202421337521.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-12
- Publication Date
- 2025-02-25
- Estimated Expiration
- 2034-06-12
AI Technical Summary
The axial flow blades in the prior art cannot take into account both reducing noise and increasing air volume.
Axial flow air blade was designed, adopting a bent swept blade structure, and an annular tail wing was set at the tail edge of the blade. The annular tail wing was an elliptical structure, located at the tip of the tail edge, with a through-type channel and ribs, and multiple internal surfaces were opened. through holes.
Through the design of the annular tail wing, the growth of the trailing vortex can be effectively suppressed, the fan noise can be improved, and the air volume can be maintained or increased.
Smart Images
Figure CN222526563U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of fans, and in particular to an axial flow fan blade and an axial flow fan. Background Art
[0002] With the in-depth application of light commercial products, the requirements for product energy efficiency are getting higher and higher, and it is very important to improve the air supply quality of key components such as axial flow fans.
[0003] In the prior art, axial flow blades usually achieve high air volume but also increase noise, which limits the further use of axial flow blades. By adding a concave notch on the trailing edge of the blade, the resonance of adjacent wake vortices is suppressed, thereby improving the fan noise. However, in a closed fan structure, the notch on the trailing edge of the axial flow blade reduces the blade's ability to do work, reduces noise, and significantly attenuates the air volume.
[0004] The prior art also has an axial flow fan blade structure, in which the blade adopts a forward-swept positive curved profile. Although a simple swept fan blade has advantages over other traditional fan blades, the advantages are limited. The swept fan blade has its own shortcomings. The fan blade is designed with a reverse-curved winglet at the top of the blade to suppress the convergence of the airflow at the suction surface and the pressure surface to form a blade tip leakage vortex. However, as the blade tip noise vortex in the high-efficiency zone from the leading edge to the trailing edge gradually increases with the increase in flow velocity to a large-scale wake vortex, which is not conducive to further control of the axial flow fan noise.
[0005] In summary, the axial flow fan blades in the prior art cannot simultaneously reduce noise and increase air volume. Utility Model Content
[0006] The utility model provides an axial flow fan blade and an axial flow fan in the embodiment to solve the problem that the axial flow fan blade in the prior art cannot take into account both reducing noise and increasing air volume.
[0007] To achieve the above-mentioned purpose, the utility model provides an axial flow fan blade, comprising: a blade, the blade having a trailing edge, the trailing edge of the blade having a trailing edge tip; an annular tail wing, the annular tail wing is connected to the blade, the annular tail wing is located at the trailing edge tip, the annular tail wing is an annular structure, and the cross-section of the annular tail wing is elliptical.
[0008] Furthermore, the blade has an outer edge; the intersection transition between the annular tail wing and the trailing edge is located at the connection point of the forward curved section of the trailing edge and the reverse curved section of the outer trailing edge; the intersection transition between the annular tail wing and the outer edge is located at h / 3 of the tip point of the trailing edge on the outer edge; h is the length value of the annular tail wing in the direction of its own axis.
[0009] Furthermore, the annular tail has a through-type channel, a part of the cross-sectional curve of the annular tail is formed by the reversely warped curved section of the outer trailing edge, and the cross-sectional curve of the annular tail satisfies the following formula:
[0010] AX 2 +BY 2 =1, the ratio of A / B is greater than 2, A and B are constants, X is the minor axis of the ellipse, and Y is the major axis of the ellipse; the annular tail wing takes the tip point of the trailing edge blade tip as the axis center.
[0011] Furthermore, the outer surface of the annular tail wing is a front profile, which is formed by the outer trailing edge reverse warping curve continuously stacked along the outer arc; the inner surface of the annular tail wing is a rear profile, which is formed by the outer trailing edge reverse warping curve continuously stacked along the outer arc line.
[0012] Furthermore, ribs for guiding airflow movement are arranged on the inner surface of the annular tail wing.
[0013] Furthermore, a plurality of through holes are provided on the inner surface of the annular tail wing.
[0014] Furthermore, the blade is a swept blade.
[0015] Furthermore, the circumference of the fitting circle formed by the outer edge is L, and the ratio of h / L is between 0.15-0.2.
[0016] According to another aspect of the utility model, an axial flow fan is provided, comprising the above-mentioned axial flow fan blade.
[0017] Furthermore, the axial flow fan also includes a guide ring, the axial flow fan blades are arranged in a guide channel of the guide ring, and the entire structure of the annular tail wing is located outside the guide ring.
[0018] The position of the annular tail wing in the axial flow fan blade is based on the characteristics of the fan blade flow channel. The annular tail wing is set at the trailing edge tip of the trailing edge in view of the position of the wake vortex and the noise vortex during the operation of the fan. The annular tail wing can limit the growth and further development of the wake vortex after it falls off the suction surface of the blade during the rotation of the axial flow fan blade. In addition, the annular tail wing needs to be set to an elliptical shape to adapt to the extended surface of the blade profile of the axial flow fan blade. The axial flow fan blade structure itself is inclined and flat, so an elliptical annular tail wing is suitable. The shape, structure and position setting of the annular tail wing can guide wind and drain. While ensuring the air volume, the axial flow fan blade can also enhance the effect of the blade on the dissipation of the channel vortex, inhibit the further growth of the wake vortex, and improve the fan noise. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is a schematic diagram of the structure of an axial flow fan blade according to an embodiment of the utility model;
[0020] Figure 2 It is a schematic diagram of the high-efficiency working area of the axial flow fan blade of the embodiment of the utility model;
[0021] Figure 3 It is a schematic diagram of the airflow direction of the axial flow fan blade of the embodiment of the utility model;
[0022] Figure 4 It is a schematic diagram of the structural position of the annular tail wing of the axial flow fan blade in an embodiment of the utility model;
[0023] Figure 5 It is a schematic diagram of the profile of the annular tail wing of the axial flow fan blade of the embodiment of the utility model;
[0024] Figure 6 It is a schematic structural diagram of the annular tail wing and blades of the axial flow fan blade of the embodiment of the utility model;
[0025] Figure 7 It is a partial structural schematic diagram of the annular tail wing of the axial flow fan blade according to an embodiment of the utility model;
[0026] Figure 8 It is a schematic diagram of the structural coordination between the trailing edge of the axial flow fan blade and the annular tail wing in an embodiment of the utility model;
[0027] Fig. 9 It is a schematic diagram of the structural coordination of the trailing edge, outer edge and annular tail wing of the axial flow fan blade in an embodiment of the utility model;
[0028] Fig.10 It is a structural schematic diagram of an axial flow fan according to an embodiment of the utility model;
[0029] Fig.11 It is a front view of an axial flow fan of the prior art;
[0030] Fig.12 is a side view of an axial flow fan of the prior art;
[0031] Fig.13 This is a front view of an axial flow fan according to an embodiment of the utility model;
[0032] Fig.14 It is a side view of the axial flow fan of the embodiment of the utility model;
[0033] Fig.15 It is a wind speed simulation diagram of an axial flow fan blade in the prior art;
[0034] Fig.16 This is a wind speed simulation diagram of the axial flow fan blade of the embodiment of the utility model;
[0035] Fig.17 It is a schematic diagram of the airflow direction of an axial flow fan in the prior art;
[0036] Fig.18 It is a schematic diagram of the airflow direction of the axial flow fan according to an embodiment of the utility model.
[0037] Description of reference numerals:
[0038] 10. Fan blade; 11. Trailing edge; 12. Outer edge; A1. Forward curved section of the trailing edge; A2. Reverse curved section of the outer trailing edge; 11a. Trailing edge blade tip; 20. Annular tail wing; 21. Front profile; 22. Rear profile; 23. Ribs; 24. Through hole; 30. Guide ring; 101. Fan blade; 102. Guide ring. DETAILED DESCRIPTION
[0039] The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.
[0040] See also Figures 1 to 10 As shown, according to an embodiment of the utility model, an axial flow fan blade is provided, the axial flow fan blade includes a blade 10 and an annular tail wing 20, the blade 10 has a trailing edge 11, and the trailing edge 11 of the blade 10 has a trailing edge tip 11a; the annular tail wing 20 is connected to the blade 10, the annular tail wing 20 is located at the trailing edge tip 11a, the annular tail wing 20 is an annular structure, and the cross-section of the annular tail wing 20 is elliptical.
[0041] The position of the annular tail wing 20 in the axial flow fan blade is based on the characteristics of the fan blade flow channel. The annular tail wing 20 is set at the trailing edge blade tip 11a of the trailing edge in view of the position of the wake vortex and the noise vortex during the operation of the fan. The annular tail wing 20 can limit the growth and further development of the wake vortex after it falls off the suction surface of the blade during the rotation of the axial flow fan blade. In addition, the annular tail wing 20 needs to be set to an elliptical shape to adapt to the extended surface of the blade shape of the axial flow fan blade. The axial flow fan blade structure itself is inclined and flat, so an elliptical annular tail wing is suitable. The shape structure and position setting of the annular tail wing 20 can guide wind and drain. While ensuring the air volume, the axial flow fan blade can also enhance the effect of the blade on the dissipation of the channel vortex, inhibit the further growth of the wake vortex, and improve the fan noise.
[0042] Combination Figures 4 to 9 Preferably, the specific structural position of the annular tail wing 20 is as follows:
[0043] The blade 10 has an outer edge 12;
[0044] The transition between the annular tail wing 20 and the trailing edge 11 is located at the connection point between the trailing edge positive curved section A1 and the outer trailing edge reverse curved section A2;
[0045] The transition between the annular tail wing 20 and the outer edge 12 is located at a distance h / 3 from the tip point of the trailing edge blade tip 11a on the outer edge 12; h is the length of the annular tail wing 20 in its own axial direction. The tip point of the trailing edge blade tip 11a is the intersection of the trailing edge and the outer edge.
[0046] The transition between the annular tail wing 20 and the trailing edge 11 is the intersection of the two structures. Figure 4 In the figure, the connection point between the trailing edge positive bending section A1 and the outer trailing edge reverse bending section A2 is at point A. The intersection transition between the annular tail wing 20 and the outer edge 12 is the intersection point between the other side of the annular tail wing and the outer edge, and point B is located at h / 3 on the tip point of the trailing edge blade tip 11a on the outer edge 12. The specific position of the annular tail wing 20 can guide the fan airflow to flow downstream, limiting the growth and further development of the wake vortex after it falls off the suction surface of the blade. The annular tail wing is a through-type channel, and the position of the annular tail wing is in the efficient working area of the fan blade, which can promote the axial movement of the airflow and increase the fan air volume.
[0047] Preferably, the annular tail wing 20 has a through-type channel, a part of the cross-sectional curve of the annular tail wing 20 is formed by the outer trailing edge reversely warped curved section A2, and the cross-sectional curve of the annular tail wing 20 satisfies the following formula:
[0048] AX 2 +BY 2 =1, the ratio of A / B is greater than 2, A and B are constants, X is the minor axis of the ellipse, and Y is the major axis of the ellipse; the annular tail wing 20 takes the tip point of the trailing edge blade tip 11a as the axis center.
[0049] Since the fan blade structure itself is inclined and flat, and the annular tail wing 20 is an elliptical structure, the above-mentioned cross-sectional curve formula of this embodiment limits the annular tail wing so that the shape of the annular tail wing can match the axial flow fan blade to the greatest extent, thereby reducing noise to the greatest extent and increasing air volume.
[0050] Combination Figure 4 and Figure 5 As shown, most of the structure of the annular tail wing 20 is arranged on the suction surface side, and the inner surface and outer surface structure of the annular tail wing 20 also need to be defined. Preferably, in this embodiment,
[0051] The outer surface of the annular tail wing 20 is a front profile 21, and the front profile 21 is formed by the outer trailing edge reverse warping curve continuously stacked along the outer arc;
[0052] The inner surface of the annular fin 20 is the rear surface 22, and the rear surface 22 is formed by continuously stacking the reverse bending of the outer trailing edge reverse warping curve along the outer arc. The surface is the curved surface area of the plate surface defined by the mold. The front surface is the curved surface area formed by the outer surface of the annular fin, and the rear surface is the curved surface area formed by the inner surface of the annular fin.
[0053] By defining the front surface 21 and the rear surface 22 as above, the annular fin 20 forms a surface structure that can smoothly guide the airflow movement. In particular, the rear surface 22 forms a through-channel that smoothly guides the airflow into the annular fin.
[0054] The curved surface formulas of the front surface and the rear surface can be:
[0055] AX 2 +BY 2 = 1, A / B > 2, where A and B are constants, X is the minor axis of the ellipse, and Y is the major axis of the ellipse.
[0056] Moreover, the structure and surface of the annular fin also satisfy the following formula: 0 < Z < h / 3, where Z is the length value of the annular fin in its own axial direction, and along the outer arc curve direction, the axis is at one point on the outer edge fitting circle.
[0057] See Figure 3 and Figure 7 As shown, ribs 23 for guiding the airflow movement are provided on the inner surface of the annular fin 20.
[0058] The ribs 23 can be spiral stripes or guiding rib strips extending along the axial direction. The ribs 23 are laid on the entire inner surface of the annular fin 20. The function of the ribs 23 is to guide the airflow to move along the channel,促使 the large-scale noise vortices in the wake to transform into small-scale eddies, so as to achieve the effect of reducing noise.
[0059] Combined with Figure 7 As shown, further preferably, a plurality of through holes 24 are provided on the inner surface of the annular fin 20. A number of through holes 24 (micro holes) are provided on the rear surface. The function of the through holes 24 is to disperse and refine some of the retained wake vortices, reduce the blocking effect caused by the edge vortices, increase the air volume of the fan, and thus reduce the overall fan noise.
[0060] In this embodiment, the blade 10 is a bowed and swept blade. The axial flow fan blade of the present utility model integrates the advantages of the bowed and swept blade and eliminates the influence of the wake vortices through the annular fin, improving the noise control. The surface of the bowed and swept blade of the blade 10 is a forward-swept and positively bowed surface. The forward sweep angle of the blade 10 can be selected between 50° and 60°. The number of the blades 10 is multiple, and an annular fin 20 is provided on each blade 10.
[0061] Preferably, the circumference of the fitting circle formed by the outer edge 12 is L, and the ratio h / L is between 0.15 and 0.2. Taking into account the size of the wind blade itself, the size of the annular tail wing and the length in the axial direction are optimized. Through the numerical ratio optimization of this embodiment, the annular tail wing can limit the growth of the wake vortex after shedding the suction surface of the blade without causing other negative effects.
[0062] Compared with conventional fan structures, the axial flow fan blades of this technical solution extend the chord length of the blades through the annular trailing edge, improve the dissipation capacity of the blade surface, reduce the noise of the fan, and increase the air volume of the fan blades. Figure 2 The difference area between the circular area of diameter D1 and the circular area of diameter D2 is the three-dimensional surface high-efficiency working area, and the annular tail wing is located in the difference area between the circular area of diameter D1 and the circular area of diameter D3 to form the outer ring of the composite high-efficiency axial flow fan. The difference area between the circular area of diameter D1 and the circular area of diameter D0 is the inner ring of the axial flow fan. The three-dimensional curved swept surface blade working range, combined with the above blade design, reasonably allocates the functions of efficient work and deep noise reduction of the fan blade. The position of the annular tail wing is in the efficient work area of the fan blade, which can promote the axial movement of the airflow and increase the air volume of the fan.
[0063] Fig.11 and Fig.12 The axial flow fan structure of the prior art is shown, and the fan blade 101 is arranged in the guide ring 102. Fig.11 and Fig.12 The axial fan structure shown in the figure is simulated. Fig.15 , shows a simulation diagram of wind speed at the circumferential section of the high-efficiency working area of the three-dimensional profile of the axial flow fan blade in the prior art. Fig.16 , shows a simulation diagram of the wind speed at the circumferential section of the efficient working area of the three-dimensional profile of the axial flow fan blade in the embodiment of the utility model. After comparison of the diagrams and calculation analysis, it can be seen that the technical solution has a better flow state in the efficient working area of the fan blade, which can promote the movement of the airflow along the axial direction and increase the fan air volume.
[0064] See also Fig.13 , Fig.14 , Fig.18 As shown, according to an embodiment of the present utility model, an axial flow fan is provided, and the axial flow fan includes the axial flow fan blades of the above embodiment.
[0065] The shape structure and position setting of the annular tail wing in the axial flow fan blade can guide wind and flow. While ensuring the air volume, the axial flow fan blade can also enhance the effect of the blade on channel vortex dissipation, inhibit the further growth of the wake vortex, and improve the fan noise.
[0066] Preferably, the axial flow fan further includes a guide ring 30 , the axial flow fan blades are arranged in a guide channel of the guide ring 30 , and the entire structure of the annular tail wing 20 is located outside the guide ring 30 .
[0067] The annular tail wing completely extends out of the top edge of the guide ring, and the entire structure is located outside the guide ring. Because the guide ring already has a complete flow channel structure inside, the external extension of the annular tail wing is expanded on the basis of the complete flow channel structure inside. This setting will not affect the fan air volume and can also reduce noise.
[0068] Fig.11 and Fig.12 The axial flow fan structure of the prior art is shown, and the fan blade 101 is arranged in the guide ring 102. Fig.11 and Fig.12 The axial fan structure shown in the figure is analyzed. Fig.17 The airflow direction of the axial flow fan of the prior art is shown. It can be seen that the axial flow blade wake vortex grows, and the wake vortex gradually grows along the reverse warping surface of the blade surface. After falling off from the suction surface of the blade, it gradually grows into a large-scale vortex, which is not conducive to noise control and also loses air volume. Fig.18 From the airflow direction of the axial flow fan of the embodiment of the utility model shown, it can be seen that the area C where the annular tail wing 20 is located can change the airflow direction by dispersing the size of the wake vortex. The annular tail wing can improve the noise of the axial flow fan and also increase the air volume of the axial flow fan.
[0069] From the comparison of the measured data in the table below, it can be seen that under the same power situation, the air volume and noise control of this technical solution are significantly improved, and the technical solution of this embodiment has better performance.
[0070] Wind blade <![CDATA[Air volume (m 3 / min)]]> Noise(dB) Power(W) Traditional technical solutions 14945 59.5 698 This technical solution 15889 58.6 688
[0071] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.
[0072] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.
[0073] Of course, the above are preferred embodiments 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 basic principles of the present invention, and these improvements and modifications are also considered to be within the protection scope of the present invention.
Claims
1. An axial flow fan blade, characterized in that: include: A blade (10), wherein the blade (10) has a trailing edge (11), and the trailing edge (11) of the blade (10) has a trailing edge tip (11a); An annular tail wing (20), the annular tail wing (20) is connected to the blade (10), the annular tail wing (20) is located at the trailing edge blade tip (11a), the annular tail wing (20) is an annular structure, and the cross section of the annular tail wing (20) is elliptical.
2. The axial flow fan blade according to claim 1, characterized in that: The blade (10) has an outer edge (12); The transition between the annular tail wing (20) and the trailing edge (11) is located at the connection point between the trailing edge forward curved section (A1) and the outer trailing edge reverse curved section (A2); The intersection transition between the annular tail wing (20) and the outer edge (12) is located at a distance h / 3 from the tip point of the trailing edge blade tip (11a) on the outer edge (12); h is the length value of the annular tail wing (20) in the direction of its own axis.
3. The axial flow fan blade according to claim 2, characterized in that: The annular tail wing (20) has a through-type channel, a part of the cross-sectional curve of the annular tail wing (20) is formed by the outer trailing edge reverse warping curved section (A2), and the cross-sectional curve of the annular tail wing (20) satisfies the following formula: AX 2 +BY 2 =1, the ratio of A / B is greater than 2, A and B are constants, X is the minor axis of the ellipse, and Y is the major axis of the ellipse; The annular tail wing (20) takes the tip point of the trailing edge blade tip (11a) as an axis.
4. The axial flow fan blade according to claim 2, characterized in that: The outer surface of the annular tail wing (20) is a front profile (21), and the front profile (21) is formed by continuously stacking the outer trailing edge reverse warping curve along the outer arc; The inner surface of the annular tail wing (20) is a rear profile (22), and the rear profile (22) is formed by the reverse bending of the outer trailing edge anti-warping curve along the outer arc line and continuously stacking.
5. The axial flow fan blade according to claim 4, characterized in that: The inner surface of the annular tail wing (20) is provided with ribs (23) for guiding the movement of airflow.
6. The axial flow fan blade according to claim 4, characterized in that: A plurality of through holes (24) are provided on the inner surface of the annular tail wing (20).
7. The axial flow fan blade according to claim 1, characterized in that: The blade (10) is a swept blade.
8. The axial flow fan blade according to claim 2, characterized in that: The circumference of the fitting circle formed by the outer edge (12) is L, and the ratio h / L is between 0.15 and 0.
2.
9. An axial flow fan, characterized in that: The invention comprises the axial flow fan blade according to any one of claims 1 to 8.
10. The axial flow fan according to claim 9, characterized in that: The axial flow fan further comprises a guide ring (30), the axial flow fan blades are arranged in a guide channel of the guide ring (30), and the entire structure of the annular tail wing (20) is located outside the guide ring (30).