CN216589274U

CN216589274U - Axial flow fan blade, fan assembly, air conditioner outdoor unit and air conditioner

Info

Publication number: CN216589274U
Application number: CN202122625948.4U
Authority: CN
Inventors: 杨锦文; 肖彪; 李彬; 陈成; 胡佳伟
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2021-10-29
Filing date: 2021-10-29
Publication date: 2022-05-24
Anticipated expiration: 2031-10-29

Abstract

The utility model relates to the technical field of air conditioners, in particular to an axial flow fan blade, a fan assembly and an air conditioner outdoor unit, wherein the axial flow fan blade comprises a hub and a plurality of blades arranged on the outer side surface of the hub, each blade comprises a first end surface and a second end surface which are arranged in a back direction, the first end surface is back to the motor connecting end of the hub, and the second end surface faces to the motor connecting end of the hub; and a plurality of base circles are set, the centers of the base circles are used as the centers of the circles, the radiuses of the base circles are sequentially increased or decreased, and the first end face and the second end face are respectively formed by fitting coordinate points of contour lines on the sections of the base circles. The axial flow fan blade can obviously improve the heat exchange efficiency and reduce the noise.

Description

Axial flow fan blade, fan assembly, air conditioner outdoor unit and air conditioner

Technical Field

The utility model belongs to the field of air conditioners, and particularly relates to an axial flow fan blade, a fan assembly, an air conditioner outdoor unit and an air conditioner.

Background

The fan system is the main component used for heat dissipation and air supply of the outdoor unit of the air conditioner. When the fan system works, the motor drives the motor shaft to rotate and pulls the fan impeller to rotate at a high speed, and mechanical energy of the rotating shaft is converted into pressure energy and kinetic energy of air through the fan system, so that heat dissipation is accelerated. In the above energy conversion process, there are often mechanical loss, volume loss, flow loss, and the like. The efficiency of a fan system is usually measured by the efficiency of the impeller (i.e. the ratio of the actual effective energy per unit time that the fan system delivers air to the power of the impeller). When the axial flow fan rotates at a high speed, the aerodynamic noise composed of the rotational noise and the eddy current noise is the main noise source of the air conditioning system. The noise level of air conditioning systems is directly related to the consumer experience with the product, and low noise is the core competitiveness of air conditioning products. The design of a fan system with high air quantity, high efficiency and low noise is of great significance under the background that the national requirements on the energy efficiency index of an air conditioning system are continuously improved and the requirements of consumers on product noise are increasingly severe.

The fan system of the outdoor unit of the air conditioner comprises a motor, a motor support, axial flow fan blades, a flow guide ring and a grid, wherein the pneumatic performance of the axial flow fan blades, the flow guide ring and the grid directly influences the heat exchange efficiency of the fan system, and the three parts have large lifting space based on the pneumatic noise optimization idea.

The present invention has been made in view of this situation.

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by the utility model is to overcome the defects of the prior art and provide an axial flow fan blade, a fan assembly, an outdoor heat exchanger and an air conditioner which can improve the heat exchange efficiency and reduce the noise.

In order to solve the technical problems, a first object of the utility model provides an axial flow fan blade, which comprises a hub and a plurality of blades arranged on the outer side surface of the hub, wherein each blade comprises a first end surface and a second end surface which are arranged in a back-to-back manner, the first end surface faces back to the motor connecting end of the hub, and the second end surface faces to the motor connecting end of the hub;

and a plurality of base circles are set, the centers of the base circles are used as the centers of the circles, the radiuses of the base circles are sequentially increased or decreased, and the first end face and the second end face are respectively formed by fitting coordinate points of contour lines on the sections of the base circles.

Further optionally, a plurality of coordinate points of the contour line of the base circle cross section satisfy the relation:

X＝A₁Y^n-1+A₂Y^n-2+A₃Y^n-3+…+A_n-1Y+A_n，

X＝B₁Z^n-1+B₂Z^n-2+B₃Z^n-3+…+B_n-1Z+B_n；

the spatial rectangular coordinate system of the points of the contour line of the base circle section satisfies the relation:

X＝a₁Y^n-1+a₂Y^n-2+a₃Y^n-3+…+a_n-1Y+a_n，

X＝b₁Z^n-1+b₂Z^n-2+b₃Z^n-3+…+b_n-1Z+b_n；

A₁、A₂、A₃…A_n、a₁、a₂、a₃…a_n、B₁、B₂、B₃…B_nand b₁、b₂、b₃…b_nAre respectively coefficients; x, Y, Z is the coordinate point of the outline of the base circle cross section.

Further optionally, a first concave rib and a second concave rib are sequentially formed on the second end face in the radial direction of the axial-flow fan blade, and the first concave rib and the second concave rib are respectively bent in the direction away from the hub.

Further optionally, the blade comprises an inner edge and an outer edge which are oppositely arranged, the inner edge is located at the connection position of the blade and the hub, and the outer edge is far away from the hub; the blade also comprises a blade front edge and a blade tail edge which are oppositely arranged, the blade front edge is positioned on the windward side of the blade, and the blade tail edge is positioned on the leeward side of the blade; the distance between the outer edge of the blade and the center of the hub is set to be R, and the following requirements are met:

the radial distance between the boundary of the first concave rib close to the hub and the center of the hub is more than or equal to 0.3R; the radial distance between the boundary of the first concave rib away from the hub and the center of the hub is less than or equal to 0.54R;

the included angle between the connecting line of the boundary of the first concave rib close to the front edge of the blade and the center of the hub and the connecting line of the tip position of the front edge of the blade and the center of the hub is more than or equal to 42 degrees; the included angle between the connecting line of the boundary of the first concave rib far away from the front edge of the blade and the center of the hub and the connecting line of the tip position of the front edge of the blade and the center of the hub is less than or equal to 103 degrees.

Further optionally, a radial distance between a boundary of the second concave rib close to the hub and the center of the hub is greater than or equal to 0.6R; the radial distance between the boundary of the second concave rib away from the hub and the center of the hub is less than or equal to 0.76R;

the included angle between the connecting line of the boundary of the second concave rib close to the front edge of the blade and the center of the hub and the connecting line of the position of the tip of the front edge of the blade and the center of the hub is more than or equal to 32 degrees; the included angle between the connecting line of the boundary of the first concave rib far away from the front edge of the blade and the center of the hub and the included angle between the position of the blade tip of the front edge of the blade and the connecting line of the center of the hub are less than or equal to 88 degrees.

Further optionally, the depth of the first concave rib and the second concave rib is 1.5 mm-2.0 mm.

Further optionally, the blade leading edge is provided with a local thickening, the local thickening and the blade are in smooth transition through a fillet, and the thickness is 1.5 mm-2 mm.

Further optionally, a saw tooth structure is formed on part or all of the blade trailing edges, and the saw tooth structure is a sine-shaped saw tooth; the radial distance from one end of the sawtooth structure far away from the hub to the center of the hub is R_sSatisfy R_s∈[0.75R，0.9R]；

The radial distance from one end of the sawtooth structure close to the hub to the center of the hub is R_eSatisfy R_e∈[0.2R，0.35R]；

The tooth height of the sawtooth structure is H, and H belongs to [12,13.5] mm;

the tooth pitch of the sawtooth structure is S, and S belongs to [8,9] mm.

Further optionally, a bending structure is formed on the outer edge of the blade, the bending structure is formed by bending part of the outer edge of the blade towards the second end surface, a set distance is formed between the first end of the bending structure and the tip of the front edge of the blade, and the second end of the bending structure extends to the tip of the tail edge of the blade.

Further optionally, the bending degree X of the bending structure satisfies: x belongs to [0, 6% ]; wherein, the bending degree X is the axial size change of the blade tip/the axial height of the hub; the axial dimension of the blade tip is changed into the height difference between the first end and the second end of the bending structure;

the bending radial starting position Y of the bending structure meets the following requirements: y belongs to [0.8R,0.9R ]; the radial starting position Y of the bending is equal to the radial position/the radius of the axial flow fan blade, and the radial position is the radial distance between the bending part of the bending structure and the center of the hub; the radius of the axial flow fan blade is the radial distance between the outer edge of the fan blade and the center of the hub;

the bending circumferential starting position Z of the bending structure meets the following requirements: z belongs to [0 degrees, 45 degrees ]; and the bending circumferential starting angle Z is an included angle between a connecting line of the blade front edge and the hub center and a connecting line of the first end of the bending structure and the hub center.

The utility model also provides a fan assembly which comprises any one of the axial flow fan blades.

Further optionally, the fan assembly further includes a flow guide ring, and the axial-flow fan blade is located in an annular space formed by the flow guide ring; the guide ring comprises a flow collecting part, a throat part and a diffusion part which are sequentially connected along the airflow direction;

the line of the flow collecting part on the radial section of the flow guide ring is an arc; the line of the throat part on the radial section of the guide ring is a straight line segment, the first end of the throat part is connected with the flow collecting part, the second end of the throat part is connected with the diffusion part, and the throat part is tangent to the flow collecting part and is vertical to the radius of the guide ring; the line type of the diffusion part on the radial section of the guide ring is an oblique line segment.

Further optionally, the radius of the arc is R_dAnd satisfies the following conditions: r_d∈[30,40]mm。

Further optionally, a gap between the throat and the outer edge of the blade is H_dAnd satisfies the following conditions: h_d∈ [5,10]mm。

Further optionally, the blade trailing edge is offset from the second end of the throat at a distance H from the closest position of the throat_fAnd satisfies the following conditions: h_f∈[-15,20]mm；

When H is present_fWhen the position is 0, the position, closest to the throat part, of the tail edge of the blade is opposite to the second end; when H is present_fWhen the value is negative, the blade trailing edge is deviated from the diffusion part at the position nearest to the throat part, and when the value is H_fPositive values of the angle of the blade trailing edge are offset toward the flow collection portion at a location nearest the throat.

Further optionally, the diffusion part and the plane of the throat part form an angle theta, which satisfies theta e [6 degrees, 10 degrees ].

The utility model also provides an air conditioner outdoor unit, which comprises a shell, wherein any one of the fan blades or any one of the fan assemblies is arranged in the shell.

Further optionally, a vent hole is formed in the housing, the fan assembly is located at the vent hole, a grille structure is mounted on the vent hole, the grille structure comprises an outer frame and an inner frame, the outer frame is annularly arranged on the peripheral wall of the mounting hole, the inner frame is located in the outer frame, and an area between the outer frame and the inner frame forms an air outlet area of the grille structure;

grid structure still includes a plurality of circumference ribs, and is a plurality of the circumference rib be with outer concentric annular setting of frame is in outer frame with between the internal frame, and a plurality of the radius of circumference rib by outer frame to the internal frame direction steadilys decrease in proper order, and the interval of adjacent circumference rib is H_tAnd satisfies the following conditions: h_t∈[8,12]mm。

Further optionally, the grid structure further comprises a plurality of radial ribs, first ends of the plurality of radial ribs are uniformly arranged along the circumferential direction of the inner frame, and second ends of the plurality of radial ribs extend from the inner frame to the outer frame and are connected with the outer frame;

the cross-section of radial rib with the contained angle of the plane that the ventilation hole belongs to is alpha, satisfies: alpha-0.023L²+0.876L+β±0.0185；

Wherein L is the minimum distance of the lattice structure from the blade;

beta is an outlet airflow angle, and the outlet airflow angle beta is formed by fitting each radial position of the radial ribs with the corresponding air outlet direction;

the cross section of the radial ribs is any circumferential cross section between the grating inner frame and the grating outer frame.

Further optionally, the outlet airflow angle β satisfies: beta ═ Px₁ ²+Qx₁-M；

Wherein: x is the number of₁Is the radial position of the cross section of the radial rib, the radial position x₁Radius R of the cross-sectional position of the radial rib_iThe diameter D of the outer frame is P, Q, M is constant, the value of P is in the range of-4938.3 +/-5.773, the value of Q is in the range of 3042 +/-3.185, and the value of M is in the range of-391.86 +/-0.844.

Further optionally, the radial ribs comprise a straight line segment, a first arc line segment and a second arc line segment which are sequentially connected from the inner frame to the outer frame;

the first end of the straight line section is connected with the inner frame, the circle center of the inner frame is positioned on the extension line of the straight line section, and the second end of the straight line section extends to 0.4R towards the outer frame_gOf R_gIs the radius of the outer frame;

the first end of the first arc line segment is connected with the second end of the straight line segment, and the second end of the first arc line segment extends to 0.8R towards the outer frame direction_gAnd the first arc segment is tangent to the straight segment;

the first end of the second arc line segment is connected with the second end of the second arc line segment, and the second end of the second arc line segment extends towards the outer frame to be connected with the outer frame; the second arc segment is tangent to the first arc segment; setting the radius of the first arc segment to be r₁The radius of the second arc segment is r₂Satisfies the following conditions: r is₂＝2～3r₁。

The utility model also provides an air conditioner which comprises the axial flow fan blade, the fan assembly or the outdoor unit of the air conditioner.

After adopting the technical scheme, compared with the prior art, the utility model has the following beneficial effects:

1. the axial flow fan blade provided by the utility model has the advantages that the fan blade has higher air volume and pneumatic efficiency at a design point through the design of parameters such as the blade profile, the installation angle and the like, and the noise of the axial flow fan blade is effectively reduced by synchronously adopting the design of bending the blade top and the sawtooth at the tail edge;

2. the guide ring provided by the utility model is matched with the axial flow fan blade, and the novel flow collecting and pressure expanding structure can reduce the impact of airflow on the fan blade, reduce the leakage of airflow on the pressure surface of the fan blade, weaken the tip vortex of the fan blade, convert partial outlet dynamic pressure into static pressure, reduce the wind speed, improve the heat exchange efficiency of a fan system, and simultaneously optimize the noise formed after the tip vortex of the fan blade falls off due to the reduction of the tip vortex of the fan blade;

3. the air outlet grille with gradually changed inclination angles is matched with the axial flow fan blades, the air outlet direction of the fan blades at different circumferential positions and the inclination angles of radial ribs of the grille can be matched, the radial divergent ribs with unique gradually changed inclination angles are provided, and the structure can effectively optimize the air outlet flow field of a fan system, so that the air volume performance of the fan system is improved and the noise of the fan system is optimized.

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the principles of the utility model and not to limit the utility model to the proper form disclosed herein. It is obvious that the drawings in the following description are only some embodiments, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:

FIG. 1: the utility model provides an axial flow fan blade structure schematic diagram.

FIG. 2: the utility model discloses an axial flow fan blade.

FIG. 3: the projection curved surface of the blade profile contour line of the axial flow fan blade is the embodiment of the utility model

FIG. 4: is a blade profile outline diagram of the embodiment of the utility model.

FIG. 5: is a concave rib characteristic diagram of the embodiment of the utility model.

FIG. 6: is a perspective view of another view angle of the axial flow fan blade of the embodiment of the utility model.

FIG. 7: the blade sawtooth structure characteristic diagram is a blade sawtooth structure characteristic diagram.

FIG. 8: is a characteristic schematic diagram of the blade bending structure of the embodiment of the utility model.

FIG. 9: a tip variation dimension characteristic diagram of a blade according to an embodiment of the utility model;

FIG. 10: the utility model discloses an assembly schematic diagram of a guide ring and an axial flow fan blade.

FIG. 11: is a D-D view of fig. 10.

FIG. 12: an enlarged view of detail C of figure 11.

FIG. 13: the notch structure of the current collecting part is shown schematically;

FIG. 14: the structure of the guide ring of the embodiment of the utility model is shown schematically.

FIG. 15 is a schematic view of: the grid structure and the axial flow fan blade assembly of the embodiment of the utility model are schematically illustrated.

FIG. 16: is a side view of fig. 15.

FIG. 17: the included angle between the cross section of the radial ribs of the grid structure and the plane of the vent holes is shown schematically.

FIG. 18: is a schematic view of the radial ribs of the grid structure of the embodiment of the utility model.

FIG. 19: an external view of an outdoor unit for an air conditioner according to an embodiment of the present invention.

FIG. 20: which is an exploded view of an outdoor unit for an air conditioner according to an embodiment of the present invention.

FIG. 21: the power comparison curve of the original fan system and the fan system of the embodiment is the same as the power comparison curve of the original fan system and the fan system of the embodiment.

FIG. 22: the noise contrast curve of the original fan system and the fan system of the embodiment is the same as the noise contrast curve of the original fan system and the fan system of the embodiment.

Wherein: 1-axial flow fan blade; 2-a flow guide ring; 3-a grid structure; 4-a motor; 5-a motor bracket; 6-a condenser; 7-a housing; 8-blade; 9-a hub; 10-the leading edge of the blade; 11-the trailing edge of the blade; 12-blade outer edge; 13-blade inner edge; 14-a first end face; 15-a second end face; 16-a saw tooth structure; 17-a bending structure; 151-first concave ribs; 152-second concave ribs; 101-local thickening of the blade; 18-a current collector portion; 181-incision; 19-throat; 20-a diffusion section; 21-an outer frame; 22-an inner frame; 23-circumferential ribs; 24-radial ribs.

It should be noted that the drawings and the description are not intended to limit the scope of the inventive concept in any way, but to illustrate it by a person skilled in the art with reference to specific embodiments.

Detailed Description

In the description of the present invention, it should be noted that the terms "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," "contacting," and "communicating" are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1

The embodiment provides an axial flow fan blade, as shown in fig. 1 to 9, including a hub 9 and a plurality of blades 8 disposed on an outer side surface of the hub 9, where the plurality of blades 8 are uniformly distributed on the outer side surface of the hub 9 at a certain installation angle, the plurality of blades 8 rotate within a circumferential range taking a center of the hub 9 as a circle center and a length of the blade 8 as a radius, and a rotation direction is as shown by an arrow in fig. 1. Setting the radius of the circle as R, and optionally, the radius of the circle is 576 mm; as shown in fig. 2, the thickness of the axial-flow fan blade 1 is set to be H, and optionally, the thickness of the blade 8 is set to be H203 mm. The blade 8 comprises a first end face 14 and a second end face 15 which are arranged in a back direction, the first end face 14 is back to the motor 4 connecting end of the hub 9, and the second end face 15 faces the motor 4 connecting end of the hub 9; the first end surface 14 is the pressure surface of the blade 8 and the second end surface 15 is the suction surface of the blade 8. A plurality of base circles with the centers of the hubs 9 as the circle centers and sequentially increasing or decreasing in radius are set, the distance between every two adjacent base circles is equal, and the first end face 14 and the second end face 15 are formed by fitting coordinate points of contour lines on the sections of the base circles respectively.

The coordinate points of the contour lines of the plurality of base circle cross sections satisfy the relation on the first end face 14: x is A₁Y^n-1+A₂Y^n-2+A₃Y^n-3+…+A_n-1Y+A_n，X＝B₁Z^n-1+B₂Z^n-2+B₃Z^n-3+…+B_n-1Z+B_n；

The spatial rectangular coordinates of the points of the contour of the base circle cross section satisfy the relation on the second end face 15:

X＝a₁Y^n-1+a₂Y^n-2+a₃Y^n-3+…+a_n-1Y+a_n，X＝b₁Z^n-1+b₂Z^n-2+b₃Z^n-3+…+b_n-1Z+b_n；

The number of the base circles can be adjusted according to actual needs, and the blade 8 of the present embodiment is explained in detail by using 6 base circles in the present embodiment. As shown in fig. 3 and 4, the first end surface 14 has a cross section S formed by pairing 6 base circles₁～S₆The coordinate points of the upper contour line are fitted, f in FIG. 4_z(x) Cylindrical coordinates at the first end face, g, of the contour of the base circle section_z(x) At the second end of the contour line being the base circle cross-sectionCylindrical coordinates of the face. The space rectangular coordinate system of the points on the contour line of the base circle section satisfies the relation: x is A₁Y⁵+A₂Y⁴+A₃Y³+A₄Y²+A₅Y+A₆，X＝ B₁Z⁵+B₂Z⁴+B₃Z³+B₄Z²+B₅Z+B₆The values of the coefficients in the equation are shown in table 1:

table 1:

base circle cross section

A₁

A₂

A₃

A₄

A₅

A₆

Section 1

0.3633

-0.433

0.001303

-8.15×10^-8

-1.82×10^-8

74.876

Section 2

0.15187

0.0139

-8.83×10^-4

1.21×10^-8

-5.30×10^-8

118.07

Section 3

0.1256

-0.0052

-6.97×10^-5

1.32×10^-5

-5.84×10^-9

160.08

Section 4

-0.0044

-0.0035

4.08×10^-6

9.80×10^-8

-6.96×10^-10

198.98

Section 5

-0.0175

-0.0023

3.17×10^-6

-4.20×10^-9

-1.18×10^-10

236.7

Section 6

-0.0141

-0.0018

1.57×10^-6

-9.58×10^-9

-3.35×10^-11

274.79

Table 2:

base circle cross section

B₁

B₂

B₃

B₄

B₅

B₆

Section 1

0.617

-1.52×10^-2

-2.36×10^-4

-1.65×10^-6

-4.89×10^-9

70.06

Section 2

0.9885

-9.50×10^-3

-1.43×10^-4

-9.82×10^-7

-3.01×10^-9

104.62

Section 3

1.0088

-4.40×10^-3

-9.14×10^-5

-1.01×10^-6

-4.44×10^-9

132.054

Section 4

0.9853

-3.18×10^-3

-5.89×10^-5

-7.42×10^-7

-3.46×10^-9

169.08

Section 5

0.778

-4.80×10^-3

-5.01×10^-5

-4.36×10^-7

-1.69×10^-9

217.64

Section 6

0.7583

-6.41×10^-3

-5.93×10^-5

-3.46×10^-7

-9.1×10^-10

259.45

The second end surface 15 of the blade 8 likewise passes through 6 base circle sections S₁～S₆Fitting coordinate points of the upper contour line, wherein a space rectangular coordinate system of points on the contour line of the base circle cross section satisfies the relation: x ═ a₁Y⁵+a₂Y⁴+a₃Y³+a₄Y²+a₅Y+a₆，X＝b₁Z⁵+b₂Z⁴+b₃Z³+b₄Z²+b₅Z+b₆The values of the coefficients in the equation are shown in table 3 and table 4.

Table 3:

base circle cross section

a₁

a₂

a₃

a₄

a₅

a₆

Section 1

0.699

-0.067

0.00171

-1.66×10^-5

2.08×10^-6

73.55

Section 2

0.08375

1.91×10^-2

-1.00×10^-3

1.20×10^-5

-5.65×10^-8

117.88

Section 3

0.12987

-0.005

-7.60×10^-5

1.37×10^-6

-6.00×10^-9

159.95

Section 4

-0.0035

3.88×10^-6

1.00×10^-7

-7.03×10^-10

198.97

Section 5

-0.01748

-0.00223

3.16×10^-6

-4.05×10^-9

-1.18×10^-10

236.7

Section 6

-0.01406

-0.00175

1.57×10^-6

-9.56×10^-9

-3.36×10^-11

274.8

Table 4:

base circle cross section

b₁

b₂

b₃

b₄

b₅

b₆

Section 1

0.8581

-9.40×10^-3

-1.80×10^-4

-1.45×10^-6

-5.19×10^-9

62.81

Section 2

1.1243

-6.40×10^-3

-1.12×10^-4

-8.50×10^-7

-3.06×10^-9

95.72

Section 3

1.13402

-3.04×10^-3

-6.80×10^-5

-8.68×10^-7

-4.38×10^-9

125.29

Section 4

1.011

-2.60×10^-3

-4.77×10^-5

-6.38×10^-7

-3.21×10^-9

164.88

Section 5

0.81

-4.80×10^-3

-4.58×10^-4

-3.13×10^-7

-1.05×10^-9

215.38

Section 6

0.79058

-5.97×10^-3

-5.54×10^-5

-3.23×10^-7

-8.4×10^-10

257.389

Further alternatively, as shown in fig. 2 and 5, the second end face 15 is sequentially formed with a first concave rib 151 and a second concave rib 152 along the radial direction of the axial-flow fan blade 1, and the first concave rib 151 and the second concave rib 152 are respectively bent towards the direction away from the hub 9. The first concave rib 151 and the second concave rib 152 are respectively configured to add a full fillet at two ends of a sector-shaped circular ring. In the embodiment, the first concave ribs 151 and the second concave ribs 152 are arranged on the second end surface 15, i.e., the suction surface, and mainly function to improve the surface load distribution, improve the working capacity of the blade, remove part of materials, reduce the cost, improve the flow separation near the wall surface, reduce the resistance and the efficiency, and reduce the noise.

Further alternatively, as shown in fig. 1, 5 and 6, the blade 8 includes an inner blade edge 13 and an outer blade edge 12 which are oppositely arranged, the inner blade edge 13 is located at the connection position of the blade 8 and the hub 9, and the outer blade edge 12 is far away from the hub 9; the blade 8 further comprises a blade front edge 10 and a blade tail edge 11 which are oppositely arranged, the blade front edge 10 is positioned on the windward side of the blade 8, and the blade tail edge 11 is positioned on the leeward side of the blade 8; the distance between the outer edge 12 of the blade and the center of the hub 9 is set to be R, and the following requirements are met:

as shown in fig. 5, the radial distance between the boundary of the first concave rib 151 close to the hub 9 and the center of the hub 9 is greater than or equal to 0.3R; the radial distance between the boundary of the first concave rib 151 away from the hub 9 and the center of the hub 9 is less than or equal to 0.54R;

an included angle between a connecting line of the boundary of the first concave rib 151 close to the blade front edge 10 and the center of the hub 9 and a connecting line of the tip position of the blade front edge 10 and the center of the hub 9 is more than or equal to 42 degrees; an included angle between a connecting line of the boundary of the first concave rib 151 far away from the blade front edge 10 and the center of the hub 9 and a connecting line of the tip position of the blade front edge 10 and the center of the hub 9 is less than or equal to 103 degrees.

Further alternatively, as shown in fig. 5, the radial distance from the boundary of the second concave rib 152 close to the hub 9 to the center of the hub 9 is greater than or equal to 0.6R; the radial distance between the boundary of the second concave rib 152 away from the hub 9 and the center of the hub 9 is less than or equal to 0.76R;

the included angle between the connecting line of the boundary of the second concave rib 152 close to the blade front edge 10 and the center of the hub 9 and the connecting line of the tip position of the blade front edge 10 and the center of the hub 9 is more than or equal to 32 degrees; the included angle between the boundary of the first concave rib 151 far away from the blade front edge 10 and the connecting line of the center of the hub 9 and the tip position of the blade front edge 10 and the connecting line of the center of the hub 9 is less than or equal to 88 degrees.

Further optionally, the depth of the first concave rib 151 and the second concave rib 152 is 1.5mm to 2 mm.

Further optionally, as shown in fig. 1, 5-8, the vane leading edge 10 is a separated air inlet end of the vane 8, and forms a structural feature of a "blunt pointed tail" with the vane trailing edge 11, that is, the vane leading edge 10 is designed with a vane local thickening 101, the thickness of the vane 8 of the vane leading edge 10 is greater than that of the vane 8 of the vane trailing edge 11, the local thickening 101 and the vane 8 are in smooth transition through a fillet, and the thickness of the local thickening 101 is 1.5mm to 2 mm. The structure accords with low-speed aerodynamic characteristics, can increase the strength of the blade 8, inhibit front edge separation vortex and reduce blade tip flutter of the blade.

Further alternatively, as shown in fig. 1-3, 5-9, the sawtooth structures 16 are formed on some or all of the blade trailing edges 11, and the sawtooth structures 16 are sinusoidal sawteeth. In the embodiment, the sawtooth structure 16 is arranged on the trailing edge 11 of the blade, so that the trailing edge shedding vortex with low frequency and large scale can be reduced into a vortex structure with high frequency and small scale, and the scattering of noise is enhanced, so that the noise reduction effect is achieved. Compare in the sawtooth structure 16 of other types, the promotion of sinusoidal sawtooth to blade 8 heat exchange efficiency is higher to the fitness of sinusoidal sawtooth and fan blade is higher, and under the less condition of air loss, the noise improvement is obvious.

Further alternatively, as shown in fig. 7, one end of the sawtooth structure 16 away from the hub 9 is at a radial distance R from the center of the hub 9_sSatisfy R_s∈[0.75R，0.9R]Preferred is R_s0.8R; the radial distance from one end of the sawtooth structure 16 close to the hub 9 to the center of the hub 9 is Re, and R is satisfied_e∈[0.2R，0.35R]Preferred radicals R_e0.25R; the tooth height of the sawtooth structure 16 is H, and H is the [12,13.5] which satisfies the condition that H belongs to]mm, preferably H-13.5 mm; the pitch of the sawtooth structure 16 is S, S ∈ [8,9]]mm, preferably 9 mm. Each characteristic parameter in the interval can realize better noise reduction effect.

Further alternatively, as shown in fig. 7 to 9, a bending structure 17 is formed on the blade outer edge 12, the bending structure 17 is formed by bending a portion of the blade outer edge 12 towards the second end surface 15, a first end of the bending structure 17 is spaced from the blade tip position of the blade front edge 10 by a set distance, and a second end of the bending structure 17 extends to the blade tip position of the blade tail edge 11. The characteristics of bending structure 17 are determined by bending degree X, radial initial position Y of bending, circumferential initial position Z of bending, and bending degree X of bending structure 17 satisfies: x ∈ [0, 6% ], preferably X ═ 6%; wherein, the bending degree X is the axial size change of the blade tip/the axial height of the hub; the axial dimension of the blade tip changes into the height difference between the first end and the second end of the bending structure 17; the bending radial starting position Y of the bending structure 17 satisfies: y ∈ [0.8R,0.9R ], preferably Y ═ 0.8R; the radial starting position Y of the bending is equal to the radial position/the radius of the axial flow fan blade 1, and the radial position is the radial distance between the bending part of the bending structure 17 and the center of the hub 9; the radius of the axial flow fan blade 1 is the radial distance between the outer edge of the fan blade and the center of the hub 9; the bending circumferential starting position Z of the bending structure 17 satisfies: z e [0 °, 45 ° ], preferably Z10 °; the bending circumferential starting angle Z is an included angle between a connecting line of the blade tip position of the blade front edge 10 and the center of the hub 9 and a connecting line of the first end of the bending structure 17 and the center of the hub 9.

The bending structure 17 arranged on the outer edge 12 of the blade has the advantages that tip leakage vortex and tip vortex are weakened; the size parameters of the bending structure 17 are subjected to multiple rounds of iterative optimization design to obtain an optimal range of bending parameters capable of achieving fan blade performance optimization, and meanwhile, errors caused by production and assembly differences are considered, and the important point is that the performance optimization effect of the axial flow fan blade 1 can be achieved only if the bending degree, the radial initial position of bending and the circumferential initial position of bending need to meet the range at the same time.

Since the impeller is a core component of the axial flow fan system outside the air conditioner chamber, the impeller is generally composed of a hub 9 and blades 8, wherein the design and optimization of the blades 8 are the main content of the fan system design. The three-dimensionally cambered vane 8 of this embodiment is typically lofted from a plurality of airfoil sections having different chord lengths, camber, relative thicknesses (the three being airfoil section geometry parameters), and stagger angles. In the design process, after parameters such as the number of the blades 8 and the hub 9 ratio are determined, blade profile geometric parameters, installation angles and the like at different positions of the fan blade are elaborately designed by using a method combining computational fluid mechanics and experimental measurement. Well designed vanes 8 generally have less flow separation near the design point and higher aerodynamic efficiency at the conditions of flow and pressure. Meanwhile, in order to further reduce the aerodynamic noise of the blade 8 and improve the efficiency, the blade 8 is usually optimized by aerodynamic modification locally, for example, the leading edge is locally thickened to increase the strength and suppress the leading edge separation vortex and reduce the blade tip flutter; bending the blade top part to weaken the blade top leakage vortex and the blade tip vortex; and applying sawteeth to the trailing edge to reduce the low-frequency large-scale trailing edge shedding vortex into a high-frequency small-scale vortex structure and enhance the scattering of noise. The application and parameter optimization of the noise reduction design means usually need to be matched with the design working conditions of the blades 8, and the optimal scheme can be obtained through repeated iteration.

Example 2

The embodiment further provides a fan assembly, and the fan assembly comprises the axial flow fan blade 1 of the embodiment 1. As shown in fig. 14, the fan assembly of the present embodiment includes a flow guide ring 2, and an axial-flow fan blade 1 is located in an annular space formed by the flow guide ring 2; as shown in fig. 12, the deflector 2 includes a collecting portion 18, a throat portion 19, and a diffuser portion 20 connected in this order in the airflow direction; the guide ring 2 is a semi-closed guide ring 2, namely the guide ring 2 only covers one part of the axial flow fan blade 1, and the airflow direction flows from the collecting part 18 to the diffusion part 20; the structure of the guide ring 2 is designed according to the air outlet speed streamline result obtained by simulation, the flow collecting part 18 is an air inlet, the speed direction of the airflow at the position is changed, the air backflow can be attenuated through the transition of the arc section, and the flow field is improved.

As shown in fig. 12, the line shape of the flow collecting part 18 in the radial section of the flow guide ring 2 is a circular arc; the line of the throat part 19 on the radial section of the guide ring 2 is a straight line segment, the first end of the throat part 19 is connected with the flow collecting part 18, the second end of the throat part 19 is connected with the diffusion part 20, and the throat part 19 is tangent to the flow collecting part 18 and is vertical to the radius of the guide ring 2; the diffuser 20 has a diagonal line in the radial cross section of the guide ring 2. The contact position of the collecting part 18 and the throat part 19 is designed to be tangent, so that the air inlet resistance can be effectively reduced, and the air inlet pneumatic performance of the collecting part is optimized.

Further alternatively, as shown in fig. 12, the rear end of the diffuser portion 20 is a folded edge, which is designed with a snap and screw hole structure, by which it is fixedly connected with the housing 7.

Further optionally, in order to meet the requirement of matching the installation size with the condenser 6 and the middle partition plate, so that the flow guide ring 2 is tightly attached to the middle partition plate and the condenser 6, smooth air inlet of the fan system is ensured, backflow and vortex cannot occur, the area of the inlet of the fan is increased to the maximum extent, and symmetrical notches 181 are arranged at the air inlet end of the flow collecting portion 18, as shown in fig. 13 and 14.

Further alternatively, as shown in FIG. 12, the radius of the arc is R_dAnd satisfies the following conditions: r_d∈[30,40]mm, preferably R_d40 mm. The arc radius has better flow collecting effect in the range, the flow field can be optimized, and the pneumatic performance of the flow guide ring 2 is optimized.

Further alternatively, as shown in FIG. 10, the gap between the throat 19 and the outer edge 12 of the blade is H_dAnd satisfies the following conditions: h_d∈[5,10]mm, preferably H_d8 mm. Theoretical tip clearance H_dThe smaller the blade tip clearance, the more favorable the leakage of the pressure surface airflow is, but the manufacturing of the blade and the assembly of the system have tolerance, and if the blade tip clearance is smaller, the difficulty of production and assembly may be increased, so that the blade tip clearance is limited by the actual production precision limit value and the blade 8 deforms when rotating at high speed, the blade tip clearance is moderate, the specific situation is determined according to the actually used blade material and size, the blade tip clearance selected in the embodiment is the blade tip clearance which is widened as much as possible on the premise that the optimal size meeting the strength requirement can ensure the performance of the blade, and the operation space of production and assembly is improved.

Further alternatively, as shown in FIG. 11, the blade trailing edge 11 is offset from the second end of the throat 19 at a distance H from the closest position of the throat 19_fAnd satisfies the following conditions: h_f∈[-15,20]mm, preferably H _f10 mm; when H is present_fAt 0, the blade trailing edge 11 is opposite the second end at the position nearest to the throat 19; when H is present_fWhen the value is negative, the trailing edge 11 of the blade is deviated toward the diffuser 20 at the position nearest to the throat 19, when H_fPositive values of the angle are the position where the blade trailing edge 11 is closest to the throat 19 and is offset towards the flow collection portion 18.

The axial position relationship between the throat part 19 and the axial flow fan blade 1 is shown in fig. 11, and the distance between the highest position of the tail edge of the fan blade and the rear end of the throat part is H_f，H_f∈[-15,20]mm, preferably H_f＝10mm，The position is also limited by the distance H between the front edge of the fan blade and the rear end of the motor 4_sIn order to prevent the fan blade from interfering with the bracket after being deformed by high-speed rotation, H is required_sNot less than 10mm, i.e. satisfying H_sOn the premise of (A), H_fCan be arbitrarily optimized in the value range, H_fThe simulation results of the size change are shown in Table 5, which can be regarded as H_fWhen the value is negative, the blade trailing edge 11 is deviated from the position nearest to the throat 19 toward the diffuser 20, and when H is_fPositive values of the angle are the position where the blade trailing edge 11 is closest to the throat 19 and is offset towards the flow collection portion 18. When H is present_fWhen the air quantity is negative, the air quantity attenuation of the fan system is large, the efficiency is low, and H is selected_fAnd if the content is more than 0, carrying out experimental verification. The verification results are shown in table 6, the air volume difference of the fan system is not large, but the noise level is good or bad, i.e. H in this embodiment_fWhen the thickness is 10mm, the effect is best.

Table 5: simulation result of different distances Hf between positions of tail edges of fan blades and rear ends of throats

H_f	Rotational speed	Air quantity	Torque moment	Full pressure of fan	Shaft power	Full pressure efficiency
							+20	840	4522.15	1.342	49.36	118.06	52.52％
+15	840	4480.12	1.328	48.92	116.80	52.12％
							+10	840	4446.10	1.313	48.48	115.49	51.84％
+5	840	4413.21	1.292	47.90	113.65	51.67％
							0	840	4320.76	1.300	48.68	114.33	51.10％
-5	840	4309.15	1.276	35.78	112.22	38.16％
							-10	840	4251.55	1.260	45.70	110.83	48.70％
-15	840	4195.49	1.246	44.85	109.59	47.70％

TABLE 6 test results of different distances Hf between the position of the trailing edge of the fan blade and the rear end of the throat

H_f	Rotational speed	Standard air quantity	Power of	Noise(s)
					20	840	5323.3	227.3	61.72
10	840	5346.2	232	61.19
					0	840	5345.6	237.367	61.74

Further alternatively, the diffuser portion 20 may be angled with respect to the plane of the throat 19 by θ, satisfying θ e [6 °, 10 ° ].

The guide ring 2 is one of the core components of the outdoor unit fan system of the air conditioner, and generally consists of a flow collecting part 18, a throat part 19 and a diffuser, and has the functions of moderating the air inlet speed of the fan blade, blocking the air outlet leakage of the blade surface, limiting the development of the tip vortex of the blade and reducing the outlet air speed, and the structural form of the guide ring can directly influence the air volume and the noise of the fan system through the matching relationship with the fan blade, thereby determining the heat exchange efficiency of the unit and the experience of the sound quality after sale.

Example 3

The third objective of this embodiment is also to provide an outdoor unit of an air conditioner, as shown in fig. 18 to 20, the air conditioner includes a casing 7, and the fan assembly of embodiment 2 is disposed in the casing 7.

The air conditioner outdoor unit comprises an axial flow fan blade 1, a flow guide ring 2, a grating, a motor 4, a motor support 5, a condenser 6 and a shell 7, wherein the axial flow fan blade 1 is installed on the motor 4, the motor 4 is installed on the motor support 5, the motor support 5 is fixedly connected with the condenser 6 and the shell 7, the flow guide ring 2 is installed inside the shell 7 and is coaxial with the axial flow fan blade 1, and the grating is installed outside the shell 7 and is coaxial with the axial flow fan blade 1;

further alternatively, the housing 7 is provided with a vent hole, the fan assembly is located at the vent hole, and the grille structure 3 is mounted on the vent hole, as shown in fig. 15 and fig. 18, the grille structure 3 includes an outer frame 21 and an inner frame 22, the outer frame 21 is annularly disposed on the peripheral wall of the mounting hole, the inner frame 22 is located in the outer frame 21, and the area between the outer frame 21 and the inner frame 22 forms the wind outlet area of the grille structure 3;

as shown in fig. 15, the grid structure 3 further includes a plurality of circumferential ribs 23, the circumferential ribs 23 are disposed between the outer frame 21 and the inner frame 22 in a ring shape concentric with the outer frame 21, the radii of the circumferential ribs 23 decrease from the outer frame 21 to the inner frame 22 in turn, and the distance between adjacent circumferential ribs 23 is H_tAnd satisfies the following conditions: h_t∈[8,12]mm, preferably H_t＝9.8mm。H_tIn order to reduce the wind resistance, the thickness of the circumferential ribs 23 needs to be as small as possible and the distance needs to be as large as possible on the premise of meeting safety regulations.

Further alternatively, as shown in fig. 15, the lattice structure 3 further includes a plurality of radial ribs 24, first ends of the plurality of radial ribs 24 are uniformly arranged along the circumferential direction of the inner frame 22, and second ends of the plurality of radial ribs 24 extend from the inner frame 22 to the outer frame 21 and are connected with the outer frame 21; the included angle between the cross section of the radial rib 24 and the plane of the vent hole is α, as shown in fig. 17, the radial rib 24 is formed by scanning a cross-sectional sketch according to a guide line sketch, wherein the inclination angle α of the cross-sectional sketch is the included angle α between the cross section of the radial rib 24 and the plane of the vent hole; satisfies the following conditions: alpha-0.023L²+0.876L + β ± 0.0185; where L is the minimum distance of the grid structure 3 from the blades 8, as shown in fig. 16; beta is an outlet airflow angle, and the outlet airflow angle beta is formed by fitting each radial position of the radial ribs 24 with the corresponding air outlet direction; the section of the radial ribs 24 is any circumferential section between the inner grid frame and the outer grid frame. The outlet airflow angle β satisfies: beta ═ Px₁ ²+Qx₁-M; wherein: x is the number of₁Radial position x being the radial position of the radial ribs 24₁The radius Ri/diameter D, P, Q, M of the outer frame 21 at the cross-sectional position of the radial rib 24 is constant, and the value of P is in the range of-4938.3 ± 5.773, the value of Q is in the range of 3042 ± 3.185, and the value of M is in the range of-391.86 ± 0.844.

The inclination angles of several groups of the fan system are obtained through calculation, the comparison air volume and the full-pressure efficiency data are calculated through simulation, the simulation result of the inclination angle alpha of the radial rib 24 is shown in table 7, the test data of the inclination angle alpha of the radial rib 24 is shown in table 8, and it can be known from table 8 that the air volume and the efficiency are improved after the angle is changed into the inclination angle at the design rotating speed point, and the optimal unit scheme is adopted for verification, aiming at the fan system in the embodiment, the noise and air volume optimization effect is most obvious when the grid inclination angle alpha is G56-66 (the grid inner frame is 56 degrees, the middle part is 66 degrees and the outer frame is 56 degrees), and the air volume is improved by 20m when the G59 (the original angle is 59 degrees) is compared with the rotating speed³H, noise reduction 0.94dB (A).

Table 7: simulation result of 24 inclination angle alpha of radial rib

Angle of inclination alpha	Rotational speed	Air quantity	Torque moment	Full pressure	Full pressure efficiency
						G59	840	5807.71	1.603	21.77	24.91％
G50-60	840	5825.71	1.597513	22.63	26.07％
						G53-63	840	5859.53	1.594458	22.56	26.19％
G56-66	840	6005.28	1.560201	22.92	27.86％
						G56-70	840	5924.59	1.551970	22.12	26.66％
G59-66	840	5814.26	1.599403	22.57	25.92％
						G60-67	840	5994.76	1.579903	23.06	26.63％
G66-70	840	5978.9	1.549539	22.36	27.25％

Table 8: radial rib 24 inclination angle alpha test data

Angle of inclination alpha	Rotational speed	Power of	Air quantity	Standard air quantity	Average value of noise
						G59	840	273.1	6285	6102.2	60.56
G60-67	840	275.7	6273.1	6080.6	60.37
						G67-70	840	274.6	6241.4	6044.9	60.41
G56-66	840	273.03	6306.4	6119.8	59.62

Further alternatively, as shown in fig. 18, the radial ribs 24 comprise a straight line segment, a first arc segment and a second arc segment connected in sequence from the inner frame 22 towards the outer frame 21; the first end of the straight line section is connected with the inner frame 22, the circle center of the inner frame 22 is positioned on the extension line of the straight line section, and the second end of the straight line section extends to 0.4R towards the outer frame 21_gA is represented by R_gIs the radius of the outer frame 21; the first end of the first arc segment is connected with the second end of the straight segment, and the second end of the first arc segment extends to 0.8R towards the outer frame 21_gAnd the first arc line segment is tangent to the straight line segment; the first end of the second arc segment is connected with the second end of the second arc segment, and the second end of the second arc segment extends towards the outer frame 21 to be connected with the outer frame 21; the second arc segment is tangent to the first arc segment; setting the radius of the first arc segment as r₁The radius of the second arc segment is r₂And satisfies the following conditions: r is₂＝2～3r₁。

The structure of the divergent rib of the embodiment obtains the rotation direction and the approximate outline of the air outlet through the simulated speed streamline, and can obtain the optimal divergent rib structure based on the outline and experimental verification.

Further alternatively, the front end of the outer frame 21 is a folded edge, which is designed with a snap and screw hole structure, by which it is fixedly connected with the housing 7.

The grid structure 3 plays a role in separating and guiding the fan from the outside, but the air outlet resistance of the system can be seriously influenced by the existence of the grid structure 3, so that the problem of reducing the noise by the air volume is solved, tests show that the air volume of the fan system is reduced by 7% -8% by using the grid structure 3, the noise is increased by about 3dB (A), and the rib structure of the grid structure 3 is an important influence factor of the noise and the air volume of the fan system. Research shows that the air outlet direction of air passing through the rotating fan blades is in a spiral divergence shape, and in order to be in accordance with the smoothness of air outlet, most of the design of the grid structure 3 abandons the original square horizontal and vertical air outlet grids, and the air outlet grids adopting circular annular matching divergence-shaped ribs are adopted. The rib structure can optimize the air-out flow field of the fan system to a certain extent, but the inclination angle of the divergent ribs also has decisive influence on the air-out flow field. Based on simulation research on the air outlet speed of a fan system, the fact that the air outlet direction of air after passing through a rotating axial flow fan blade 1 is in a spiral divergence shape is obtained, and the air outlet speed direction can also change along with the change of the circumferential position from the circle center of the fan to the blade top.

The fan system with obvious pneumatic performance advantages can be obtained by adopting the matching scheme of the fan blades, the guide ring 2 and the grid structure 3 in the outdoor unit of the air conditioner, the test data of the original fan system is shown in table 9, the test data of the fan system of the embodiment is shown in table 10, the power comparison curve of the original fan system and the fan system of the embodiment under the same air volume is shown in fig. 21, and the noise comparison curve of the original fan system and the fan system of the embodiment under the same air volume is shown in fig. 22.

TABLE 9 original wind turbine system test data

TABLE 10 test data for fan systems

As can be seen from the experimental data in tables 9 and 10 and the comparison curves in fig. 21 and 22, the performance of the blower system of the embodiment is reduced by 50-75W compared with the input power value of the motor 4 of the original blower system under the same air volume; under the same air volume working condition, the noise value of the fan system is reduced by 1-1.5 dB (A) compared with the noise value of the original fan system. The realization data shows that the fan system of the embodiment has the advantages of obviously improving the heat exchange efficiency of the air conditioner and reducing the noise of the whole machine, and can effectively solve the problems of larger air quantity attenuation and larger noise of the original fan system.

Example 4

The present embodiment further provides an air conditioner, which includes the axial flow fan blade 1 of embodiment 1, or includes the fan assembly of embodiment 2, or the outdoor unit of air conditioner of embodiment 3.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the utility model as defined by the appended claims.

Claims

1. The axial flow fan blade is characterized by comprising a hub and a plurality of blades arranged on the outer side surface of the hub, wherein each blade comprises a first end surface and a second end surface which are arranged in a back-to-back mode, the first end surface faces away from a motor connecting end of the hub, and the second end surface faces towards the motor connecting end of the hub;

setting a plurality of base circles with the centers of the hubs as the circle centers and sequentially increasing or decreasing the radiuses, wherein the first end surface and the second end surface are respectively formed by fitting coordinate points of contour lines on the sections of the base circles;

the coordinate points of the contour lines of the base circle cross sections satisfy the relation:

X＝A₁Y^n-1+A₂Y^n-2+A₃Y^n-3+…+A_n-1Y+A_n，

X＝B₁Z^n-1+B₂Z^n-2+B₃Z^n-3+…+B_n-1Z+B_n；

X＝a₁Y^n-1+a₂Y^n-2+a₃Y^n-3+…+a_n-1Y+a_n，

X＝b₁Z^n-1+b₂Z^n-2+b₃Z^n-3+…+b_n-1Z+b_n；

2. The axial flow fan blade according to claim 1, wherein the second end face is formed with a first concave rib and a second concave rib in sequence along a radial direction of the axial flow fan blade, and the first concave rib and the second concave rib are respectively bent in a direction away from the hub.

3. The axial flow fan blade of claim 2, wherein the blade comprises an inner blade edge and an outer blade edge which are arranged opposite to each other, the inner blade edge is located at the connection position of the blade and the hub, and the outer blade edge is far away from the hub; the blade also comprises a blade front edge and a blade tail edge which are oppositely arranged, the blade front edge is positioned on the windward side of the blade, and the blade tail edge is positioned on the leeward side of the blade; the distance between the outer edge of the blade and the center of the hub is set to be R, and the following requirements are met:

4. The axial flow fan blade of claim 3,

the radial distance between the boundary of the second concave rib close to the hub and the center of the hub is more than or equal to 0.6R; the radial distance between the boundary of the second concave rib away from the hub and the center of the hub is less than or equal to 0.76R;

the included angle between the connecting line of the boundary of the second concave rib close to the front edge of the blade and the center of the hub and the included angle between the tip position of the front edge of the blade and the connecting line of the center of the hub are more than or equal to 32 degrees; the included angle between the connecting line of the boundary of the first concave rib far away from the front edge of the blade and the center of the hub and the included angle between the position of the blade tip of the front edge of the blade and the connecting line of the center of the hub are less than or equal to 88 degrees.

5. The axial flow fan blade of claim 3,

the depth of the first concave rib and the second concave rib is 1.5 mm-2.0 mm.

6. The axial flow fan blade of claim 3, wherein the front edge of the blade is provided with a local thickening, the local thickening and the blade are in smooth transition through a fillet, and the thickness is 1.5 mm-2 mm.

7. The axial flow fan blade according to claim 6, wherein a saw-tooth structure is formed on a part or all of the trailing edge of the fan blade, and the saw-tooth structure is a sine-shaped saw tooth; the radial distance from one end of the sawtooth structure far away from the hub to the center of the hub is R_sSatisfy R_s∈[0.75R，0.9R]；

The tooth height of the sawtooth structure is H, and H belongs to [12,13.5] mm;

the tooth pitch of the sawtooth structure is S, and S belongs to [8,9] mm.

8. The axial flow fan blade according to claim 3, wherein a bent structure is formed on the outer edge of the blade, the bent structure is formed by bending part of the outer edge of the blade towards the second end face, a set distance is formed between the first end of the bent structure and the tip of the front edge of the blade, and the second end of the bent structure extends to the tip of the tail edge of the blade.

9. The axial flow fan blade of claim 8,

the bending degree X of the bending structure meets the following requirements: x belongs to [0, 6% ]; wherein, the bending degree X is the axial size change of the blade tip/the axial height of the hub; the axial dimension of the blade tip is changed into the height difference between the first end and the second end of the bending structure;

10. A fan assembly, characterized in that it comprises an axial fan blade according to any one of claims 1 to 9.

11. The fan assembly of claim 10 further comprising a flow guide ring, wherein the axial fan blades are positioned in an annular space formed by the flow guide ring; the guide ring comprises a flow collecting part, a throat part and a diffusion part which are sequentially connected along the airflow direction;

12. The fan assembly of claim 11 wherein the arc has a radius R_dSatisfies the following conditions: r_d∈[30,40]mm。

13. The fan assembly of claim 12,

the gap between the throat part and the outer edge of the blade is H_dAnd satisfies the following conditions: h_d∈[5,10]mm。

14. The fan assembly of claim 13,

the blade tail edge is deviated from the second end of the throat part at the position closest to the throat part by a distance H_fSatisfies the following conditions: h_f∈[-15,20]mm；

15. The fan assembly of claim 14,

the included angle between the diffusion part and the plane where the throat part is located is theta, and theta epsilon [6 degrees and 10 degrees ] is satisfied.

16. An outdoor unit for an air conditioner, comprising a housing, wherein the axial flow fan blade of any one of claims 1 to 9 or the fan assembly of any one of claims 10 to 15 is disposed in the housing.

17. The outdoor unit of claim 16, wherein the housing has a ventilation hole, the fan assembly is located at the ventilation hole, and a grille structure is installed on the ventilation hole and includes an outer frame and an inner frame, the outer frame is annularly disposed on a peripheral wall of the ventilation hole, the inner frame is located in the outer frame, and a region between the outer frame and the inner frame forms a wind outlet region of the grille structure;

the grid structure still includes a plurality of circumference ribs, and is a plurality of circumference rib be with outer concentric annular setting of frame is in outer frame with between the inner frame, and a plurality of the radius of circumference rib by outer frame to the inner frame direction decreases progressively in proper order, and the interval of adjacent circumference rib is H_tAnd satisfies the following conditions: h_t∈[8,12]mm。

18. The outdoor unit of claim 17, wherein the grille structure further comprises a plurality of radial ribs, first ends of the plurality of radial ribs are uniformly arranged along a circumferential direction of the inner frame, and second ends of the plurality of radial ribs extend from the inner frame to the outer frame and are connected to the outer frame;

Wherein L is the minimum distance of the lattice structure from the blade;

19. The outdoor unit of claim 18, wherein the outlet airflow angle β satisfies: beta ═ Px₁ ²+Qx₁-M；

20. The outdoor unit of claim 19, wherein the radial ribs comprise a straight line segment, a first arc segment and a second arc segment sequentially connected from the inner frame to the outer frame;

the first end of the straight line section is connected with the inner frame, the circle center of the inner frame is positioned on the extension line of the straight line section, and the second end of the straight line section extends to 0.4R towards the outer frame_gA is represented by R_gIs the radius of the outer frame;

the first end of the second arc line segment is connected with the second end of the second arc line segment, and the second end of the second arc line segment extends towards the outer frame to be connected with the outer frame; the second arc segment is tangent to the first arc segment; setting the radius of the first arc segment to be r₁The radius of the second arc segment is r₂And satisfies the following conditions: r is₂＝2～3r₁。

21. An air conditioner, characterized in that, it includes the axial-flow fan blade of any one of claims 1-9, or includes the fan assembly of any one of claims 10-15, or includes the outdoor unit of air conditioner of any one of claims 16-20.