CN112648234A

CN112648234A - Axial flow fan blade and fan with same

Info

Publication number: CN112648234A
Application number: CN202011642326.6A
Authority: CN
Inventors: 张驰; 柳洲; 梁浩; 麦焕; 刘阳清; 张晓泉
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2021-04-13

Abstract

The invention provides an axial flow fan blade and a fan with the same, wherein the axial flow fan blade comprises a hub and blades, the blades are provided with a front edge and a rear edge which are oppositely arranged along a rotating direction, a reference variable cylinder S is arranged, and the cylinder S and the hub are concentrically arranged; the midpoint of a cross section of the cylinder S intersected with the blade is a, a connecting line of the midpoint of the blade root of the blade and the center of the hub is L2, a connecting line of the point a and the center of the hub is L3, and an included angle between L2 and L3 is a net bending angle A1 of the blade; the maximum radius of the blade is R, the radius of the cylinder S is R, the ratio of R to R is between 0.4 and 0.95, when the ratio of R to R is gradually increased, the angle value of A1 is gradually increased, and the angle value of A1 is between 5 and 43 degrees. Through the technical scheme provided by the application, the problem that the air supply efficiency of the blades in the prior art is low can be solved.

Description

Axial flow fan blade and fan with same

Technical Field

The invention relates to the technical field of axial flow fan blades, in particular to an axial flow fan blade and a fan with the same.

Background

At present, in the working process of the existing axial flow fan blade, the main flow speed in a boundary layer is low, and the centrifugal force of the fan blade is larger than the radial pressure gradient, so that low-energy fluid in the boundary layer is radially outwards migrated and accumulated near the blade top, the blade top loss and the blade top stall are increased, and the air supply efficiency is influenced.

Disclosure of Invention

The invention provides an axial flow fan blade and a fan with the same, and aims to solve the problem that the air supply efficiency of the fan blade in the prior art is low.

According to one aspect of the invention, the axial flow fan blade comprises a hub and a blade, wherein the blade is provided with a front edge and a rear edge which are oppositely arranged along a rotating direction, a reference variable cylinder S is arranged, and the cylinder S and the hub are concentrically arranged; the midpoint of a cross section of the cylinder S intersected with the blade is a, a connecting line of the midpoint of the blade root of the blade and the center of the hub is L2, a connecting line of the point a and the center of the hub is L3, and an included angle between L2 and L3 is a net bending angle A1 of the blade; the maximum radius of the blade is R, the radius of the cylinder S is R, the ratio of R to R is between 0.4 and 0.95, when the ratio of R to R is gradually increased, the angle value of A1 is gradually increased, and the angle value of A1 is between 5 and 43 degrees.

Further, the intersection point of the cylinder S and the front edge of the blade is C, the connecting line of the C and the center of the hub is L4, the tangent line of the front edge of the blade at the point C is L5, the included angle between L5 and L4 is a leading edge guide edge bending angle A2, wherein when the ratio of R/R is gradually increased, the angle value of A2 is gradually increased, and the angle value of A2 is between 29 degrees and 59 degrees.

Further, the intersection point of the cylinder S and the rear edge of the blade is D, the connecting line of the D and the center of the hub is L6, the tangent line of the rear edge of the blade at the point D is L7, the included angle between L7 and L6 is a rear edge guide edge bending angle A3, wherein when the ratio of R/R is gradually increased, the angle value of A3 is gradually increased, and the angle value of A3 is between 31 degrees and 42 degrees.

Further, the included angle between the chord length of the section obtained by intersecting the cylinder S and the blade and the rotating plane of the blade is the blade installation angle Q, wherein when the ratio of R/R is gradually increased, the angle value of Q is gradually reduced, and the angle value of Q is between 32.5 degrees and 28 degrees.

Further, the chord length of the section obtained by the intersection of the cylinder S and the blade is b, wherein when the ratio of R/R is gradually increased, the ratio of b/R is also gradually increased, and the ratio of b/R is between 0.5 and 1.5.

Further, an included angle alpha is arranged between the front edge of the blade and the blade top of the blade, and the angle value of the alpha is 40-50 degrees.

Further, the maximum diameter of the blade is d1, the diameter of the hub is d2, wherein the ratio of d2/d1 is between 0.25 and 0.35.

Furthermore, the axial-flow fan blade comprises a plurality of blades, and the number of the blades is odd.

According to another aspect of the invention, a fan is provided, which comprises the fan provided above.

When the technical scheme of the invention is applied, when the blade is designed, a reference variable cylinder S is arranged, and the cylinder S and the hub are concentrically arranged, wherein the midpoint of the cross section of the intersection of the cylinder S and the blade is a, the connecting line of the midpoint of the blade root of the blade and the center of the hub is L2, the connecting line of the point a and the center of the hub is L3, the included angle between L2 and L3 is the net bending angle A1 of the blade, and when the ratio of R/R is between 0.4 and 0.95, the angle value of A1 is correspondingly taken between 5 degrees and 43 degrees.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic structural diagram of an axial-flow fan blade according to an embodiment of the present invention;

FIG. 2 illustrates a cross-section of an axial flow fan blade intersecting a cylinder S provided in accordance with an embodiment of the present invention;

FIG. 3 shows a schematic view of the blade of FIG. 1;

fig. 4 is a schematic structural diagram of an axial-flow fan blade provided in accordance with an embodiment of the present invention;

fig. 5 shows a left side view of an axial-flow fan blade provided according to an embodiment of the present invention.

Wherein the figures include the following reference numerals:

10. a hub; 20. a blade; 21. a leading edge; 22. a trailing edge; 23. leaf tops; 24. a blade root; 25. a suction surface; 26. a pressure surface.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1 to 5, the present application provides an axial flow fan blade, which includes a hub 10 and a blade 20, where the blade 20 has a leading edge 21 and a trailing edge 22 opposite to each other along a rotation direction, and when performing a size design on the axial flow fan blade, a reference variable cylinder S needs to be introduced, where the cylinder S is concentrically arranged with the hub 10, a center of the hub 10 is O, and the cylinder S intersects with the blade 20 to obtain a corresponding parameter value. Specifically, the midpoint of a cross section of the cylinder S intersecting the blade 20 is a, a connecting line between the midpoint of the blade tip 23 of the blade and a is L1, a connecting line between the midpoint of the blade root 24 of the blade and the center of the hub 10 is L2, and a connecting line between the a point and the center of the hub 10 is a connecting line between the intersection point of L1 and the cylinder S and the center of the hub 10, the connecting line is L3, and an included angle between L2 and L3 is a net bending angle a1 of the blade, wherein the maximum radius of the blade 20 is R, the radius of the cylinder S is R, and when the ratio of R/R is between 0.4 and 0.95, the angle value of a1 is correspondingly set between 5 ° and 43 °.

When the blade 20 is designed, the axial flow fan blade provided by the application is provided with the reference variable cylinder S, the cylinder S and the hub 10 are arranged concentrically, wherein, the midpoint of the cross section of the cylinder S intersected with the blade 20 is a, the connecting line of the midpoint of the blade root 24 of the blade and the center of the hub 10 is L2, the connecting line of the point a and the center of the hub 10 is L3, the included angle between L2 and L3 is the net bending angle A1 of the blade, when the ratio of R/R is between 0.4 and 0.95, correspondingly, the angle value of A1 is set to be between 5 degrees and 43 degrees, so that the degree of sweep of the blade top 23 of the blade can be limited, the centrifugal force of fluid in the blade boundary layer can be reduced through the limitation, so that the blade top stall of the blade can be effectively inhibited, the energy loss at the blade top of the blade is reduced, and the air supply efficiency of the blade is improved.

Specifically, in the present embodiment, when the value of R/R is 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, and 0.95, the net blade bend angle a1 corresponds to values of 5 °, 9 °, 13 °, 15 °, 18 °, 22 °, 25 °, 28 °, 32 °, 35 °, 39 °, and 43 °.

Further, the intersection point of the cylinder S and the leading edge 21 of the blade is set to be C, the line connecting C and the center O of the hub 10 is L4, the tangent line of the leading edge 21 of the blade at the point C is L5, and the included angle between L5 and L4 is a leading edge bending angle a2, wherein the angle value of a2 is set to be 29 ° to 59 °. The sweep degree of the leading edge of the blade can be limited by limiting the angle A2, and the sweep degree of the leading edge can be increased by the design, so that the sweep degree of the leading edge is gradually increased from the blade root 24 to the blade top 23. The backflow problem of the impeller front edge 21 can be eliminated through the arrangement, the low-energy fluid in the end wall area is absorbed into the high-energy main flow in the blade, and the gathering of the low-energy fluid at the end part is weakened, so that the flow loss and the flow blockage are weakened. Moreover, the design can weaken the influence of the casing and the end wall of the hub on the gas flow in the flow passage, inhibit the accumulation of low-energy fluid, accelerate the attenuation speed of the wake of the blade 20, obviously improve the internal flow state of the blade 20 by the secondary flow characteristic that the low-energy fluid of the end wall near the suction surface 25 of the blade is carried by the main flow to the downstream, thereby inhibiting the falling of the surface vortex of the blade 20, reducing the broadband noise of the blade 20 and improving the tone quality. Moreover, experimental simulation shows that increasing the degree of sweep of the leading edge 21 of the blade can significantly increase the static pressure values of the suction surface 25 and the pressure surface 26 at the leading edge 21 of the blade, and improve the distribution of the pressure gradient on the surface of the blade, thereby increasing the effective working area on the surface of the blade and improving the performance of the blade.

In the present embodiment, when R/R has values of 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, and 0.95, the leading edge guide bend angle a2 has corresponding values of 29 °, 30 °, 32 °, 35 °, 38 °, 42 °, 46 °, 50 °, 53 °, 56 °, and 59 °.

Specifically, the intersection point of the cylinder S and the trailing edge 22 of the blade is set to be D, the connecting line of D and the center of the hub 10 is set to be L6, the tangent line of the trailing edge 22 of the blade at the point D is set to be L7, the included angle between L7 and L6 is the trailing edge guide edge bending angle A3, and the angle value of A3 is set to be 31 ° to 42 °. The sweep of the trailing edge 22 of the blade can be limited by the above design, so that the sweep angle of the trailing edge 22 of the blade increases gradually from the blade root 24 to the blade tip 23. When the turbulent boundary of the blade surface passes through the trailing edge of the blade, local pulsating force can be generated, and the karman vortex street at the trailing edge of the blade also generates local pulsating force with narrower frequency characteristics. By improving and limiting the trailing edge leading edge bending angle A3, vortex shedding at the blade trailing edge 22 can be effectively inhibited, and blade noise is reduced.

In the present embodiment, when the value of R/R is 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, and 0.95, the corresponding values of the trailing edge guide bend angle a3 are 31 °, 32 °, 33 °, 35 °, 36 °, 37 °, 39 °, 40 °, 41 °, and 42 °.

As shown in fig. 2, the chord length of the section where the cylinder S intersects the blade 20 is included with the rotation plane of the blade 20 by the blade installation angle Q, wherein the value of Q is set between 32.5 ° and 28 °. Through the design, the blade installation angle Q of the blade 20 at different cross-sectional positions can be defined, so that the installation angle gradually decreases from the blade root 24 to the blade tip 23.

If the blade installation angle is too large, the space for air fluid to flow through the impeller is reduced, the inlet resistance is increased, and the fluid flow is blocked, and the large installation angle increases the load on the blade, thereby affecting the pressure distribution on the surface of the blade, increasing the pressure pulsation, and causing the load noise of the blade to be increased. If the blade installation angle is too small, the lift force of the blade is reduced, the axial working capacity of the blade on air fluid is weakened, the energy loss of airflow is increased, and the efficiency of the fan is reduced. Through the design of this application, can make blade installation angle set up rationally, make the air fluid of impeller import department get into the impeller region smoothly, promote complete machine efficiency.

In the present embodiment, when the value of R/R is 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9 and 0.95, the respective values of the blade setting angles Q thereof are 32.45 °, 32.42 °, 32.33 °, 32.25 °, 32.08 °, 31.94 °, 31.68 °, 31.25 °, 30.59 °, 29.92 °, 29.84 ° and 28.17 °. In the embodiment, the blade installation angle at the blade root 24 is set to be larger, so that the strength of the blade can be effectively ensured, and the overlarge load of the blade is avoided; the blade mounting angle at the blade top 23 is gradually reduced, so that the overall load of the blade can be effectively reduced, and the pressure of the motor is reduced.

Wherein, the chord length of the cross section obtained by intersecting the cylinder S and the blade 20 is set as b, which is the connecting line of the two end points of the cross section. When the ratio of R/R becomes larger, the ratio of b/R also becomes larger, and the ratio of b/R is set between 0.5 and 1.5. The main source of the noise generated by the fan is the airflow pulsating force acting on the blades, and the airflow pulsating force can cause the separation of blade surface vortex and vortex, thereby generating the noise. Through the design, the chord length of the blade on different sections can be limited, so that the chord length size of the blade is gradually increased from the blade root 24 to the blade top 23, and the design can effectively inhibit and reduce the formation and separation of blade surface vortex, thereby achieving the aim of reducing noise. In addition, in the technical scheme, the pressure gradient between the blade root 24 and the blade top 23 can be reduced, and the purpose of reducing the low power consumption area of the blade is achieved.

In this example, when the R/R values are 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9 and 0.95, the b/R values are 0.548, 0.685, 0.755, 0.867, 0.899, 0.972, 1.054, 1.142, 1.204, 1.288, 1.386 and 1.472, respectively.

Specifically, an included angle α is set between the leading edge 21 of the blade and the blade tip 23 of the blade, and the angle value of α is set to 40 ° to 50 °. The design can effectively reduce the generation of tip vortex and front edge separation vortex, thereby achieving the purpose of reducing aerodynamic noise. Specifically, with the tangent line of the leading edge 21 of the blade at the intersection of the leading edge and the blade tip being L8, the tangent line of the blade tip 23 of the blade at the intersection of the leading edge and the blade tip being L9, the included angle between L8 and L9 is set to α.

As shown in FIG. 4, the maximum diameter of the blade 20 is set to d1, the diameter of the hub 10 is set to d2, and the ratio of d2/d1 is set between 0.25 and 0.35. The size of the hub 10 can be limited through the technical scheme, and the ratio is too large, so that the efficiency of the fan is reduced, and the pneumatic performance of the whole machine is reduced; conversely, if the ratio is too low, the separation of the air flow at the root 24 of the blade may occur, and even the fan may stall. Through the limitation, the fan can be controlled within a reasonable range, the efficiency of the fan is ensured, and the phenomenon of air flow separation is avoided.

Specifically, the axial flow fan blade includes a plurality of blades 20, and the number of the blades 20 is set to be an odd number. In the present embodiment, the number of the blades 20 is 3, but the number of the blades with odd numbers such as 5, 7, 9, etc. may be adjusted and selected. The small number of the blades can reduce the overall acting area of the fan blades, thereby influencing the air quantity of the fan blades; the large number of the blades can increase the area ratio of the blades at the flow cutoff surface, so that the area of a fluid flow passage is reduced, and the overall load of the fan blade is increased, thereby increasing the cost of the motor. Therefore, a reasonable number of vanes is selected according to the actual working condition. The axial flow fan blades are arranged to be odd number blades, so that the fan blades can be prevented from being in a symmetrical structure, and the possibility of fatigue fracture and vibration generated when the fan blades run is reduced.

The comparison of the operating parameters of the axial flow fan blade provided by the application and the fan blades in the prior art is detailed as shown in the following table:

scheme(s)	Outlet wind speed (m/s)	Distance of air supply (m)	Air volume (m)³/min)	Energy efficiency	Noise (dB)
						Fan blade in prior art	5.3	8.8	15.18	1.03	46.3
Fan blade	5.8	11	17.21	1.26	44.3

Known by the table, under with the rotational speed, fan blade performance, the efficiency that this application designed all promote with prior art, and gather wind effect and have obvious improvement, the noise peak value of fan blade in the operation in-process obviously reduces in addition.

Through the technical scheme that this application provided, can improve the problem that traditional fan blade air supply was dispersed, the effect of gathering wind of reinforcing axial fan blade air supply improves the blade air supply amount of wind, has improved axial air supply and circumference air supply export wind speed and air supply distance, and in addition, this application fan blade can also improve the efficiency, reduces motor cost.

The application further provides a fan, and the fan comprises the axial flow fan blade provided by the embodiment.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and in the case of not making a reverse description, these orientation words do not indicate and imply that the device or element being referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be considered as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The axial flow fan blade is characterized by comprising a hub (10) and a blade (20), wherein the blade (20) is provided with a front edge (21) and a rear edge (22) which are oppositely arranged along the rotation direction, a reference variable cylinder S is arranged, and the cylinder S and the hub (10) are concentrically arranged;

the midpoint of a cross section of the cylinder S intersected with the blade (20) is a, a connecting line of the midpoint of a blade root (24) of the blade and the center of the hub (10) is L2, a connecting line of the point a and the center of the hub (10) is L3, and an included angle between L2 and L3 is a net bending angle A1 of the blade;

wherein the maximum radius of the blade (20) is R, the radius of the cylinder S is R, the ratio of R/R is between 0.4 and 0.95, when the ratio of R/R becomes larger gradually, the angle value of A1 also increases gradually, and the angle value of A1 is between 5 degrees and 43 degrees.

2. The axial-flow fan blade according to claim 1, wherein the intersection point of the cylinder S and the leading edge (21) of the blade is C, the line connecting C and the center of the hub (10) is L4, the tangent line of the leading edge (21) of the blade at the point C is L5, the included angle between L5 and L4 is a leading edge bending angle A2, wherein when the ratio of R/R becomes larger gradually, the angle value of A2 also increases gradually, and the angle value of A2 is between 29 ° and 59 °.

3. The axial-flow fan blade according to claim 1, characterized in that the intersection point of the cylinder S and the trailing edge (22) of the blade is D, the line connecting D and the center of the hub (10) is L6, the tangent line of the trailing edge (22) of the blade at the point D is L7, the included angle between L7 and L6 is a trailing edge guide edge bending angle A3, wherein when the ratio of R/R becomes larger gradually, the angle value of A3 also becomes larger gradually, and the angle value of A3 is between 31 ° and 42 °.

4. The axial-flow fan blade according to claim 1, wherein an included angle between a chord length of a cross section obtained by intersecting the cylinder S and the blade (20) and a rotation plane of the blade (20) is a blade installation angle Q, wherein when a ratio of R/R becomes larger gradually, an angle value of Q is reduced gradually, and the angle value of Q is between 32.5 ° and 28 °.

5. The axial-flow fan blade according to claim 1, wherein the chord length of the section obtained by intersecting the cylinder S and the blade (20) is b, wherein when the ratio of R/R is gradually increased, the ratio of b/R is also gradually increased, and the ratio of b/R is between 0.5 and 1.5.

6. The axial-flow fan blade according to claim 1, wherein an included angle α is provided between the leading edge (21) of the blade and the tip (23) of the blade, and the value of the angle α is 40 ° to 50 °.

7. The axial fan blade according to claim 1, characterized in that the maximum diameter of the blade (20) is d1 and the diameter of the hub (10) is d2, wherein the ratio d2/d1 is between 0.25 and 0.35.

8. The axial fan blade according to any one of claims 1 to 7, characterized in that it comprises a plurality of blades (20), the number of said plurality of blades (20) being an odd number.

9. A fan, characterized in that it comprises a fan according to any one of claims 1 to 8.