CN216554588U

CN216554588U - Blade for centrifugal fan impeller, centrifugal fan impeller using blade and centrifugal fan

Info

Publication number: CN216554588U
Application number: CN202122601153.XU
Authority: CN
Inventors: 李晓强
Original assignee: Ningbo Fotile Kitchen Ware Co Ltd
Current assignee: Ningbo Fotile Kitchen Ware Co Ltd
Priority date: 2021-10-27
Filing date: 2021-10-27
Publication date: 2022-05-17
Anticipated expiration: 2031-10-27

Abstract

The utility model relates to a blade for a centrifugal fan impeller, and the centrifugal fan impeller and the centrifugal fan using the same. The arrangement of the first holes on the front edge area of the blade can enable the vortex separation point to move backwards along the flow direction, and the arrangement of the second holes on the rear edge area of the blade can inhibit the flow separation at the position of the area, so that the noise problem can be effectively reduced; on the other hand, because the middle area of the blade is not provided with the through hole, the blade can be ensured to have enough pressure rise, and the pneumatic performance is not lost.

Description

Blade for centrifugal fan impeller, centrifugal fan impeller using blade and centrifugal fan

Technical Field

The utility model relates to the technical field of centrifugal fans, in particular to a blade for a centrifugal fan impeller, and the centrifugal fan impeller and a centrifugal fan applying the blade.

Background

The centrifugal fan is an important air supply device and is commonly used in products such as a range hood, an air conditioner and the like. Centrifugal fans generally include a volute and an impeller disposed within the volute, the impeller including a front disk, a rear disk, and blades circumferentially spaced therebetween. The operating noise of the centrifugal fan directly affects the user experience, wherein the aerodynamic noise of the centrifugal fan can be divided into rotational noise and vortex noise according to the generated reason, the rotational noise is caused by the pressure pulsation generated by the interaction of the blade and the air flow, and is also called discrete noise or blade passing frequency noise. The vortex noise is mainly caused by the resistance of the airflow at the blade boundary layer to generate vortex, the vortex shedding with the main airflow at the blade trailing edge, blade tip leakage flow and the like.

At present, a blade perforation noise reduction scheme is adopted, and the principle that the open-hole jet flow is used for inhibiting the generation of the vortex of the non-working surface of the blade and the separation point is applied. Because the flow of the fluid in the boundary layer has a velocity gradient, the closer to the surface of the blade, the greater the influence of viscosity on the flow velocity, when the kinetic energy of the fluid in the boundary layer cannot overcome the friction force of the surface of the blade, the surface of the blade may form a vortex which is taken away by the main flow of the gas to generate vortex shedding, and the vortex shedding and the generation continuously radiate energy in the form of noise. After the blade is perforated, partial airflow on the pressure surface of the blade flows to the suction surface, and the suction surface has larger kinetic energy to overcome the friction force on the surface of the blade, so that the generation and falling of vortex are inhibited. For example, chinese utility model patent application with application number CN201821865798.6 (publication number CN209856100U) discloses "a wind wheel, a fan and a range hood", which is to balance the pressure distribution in the impeller flow passage and reduce the generation of vortex by providing a plurality of through holes distributed at intervals on the blades of the wind wheel, so as to reduce the noise generated by the rotation of the wind wheel.

The blades of the impeller in the above patent have certain disadvantages, firstly, the through holes of the blades are arranged on the area between the front edge and the center line of the blades, and the structural arrangement can cause leakage flow and insufficient pressure rise in the middle area of the blades on one hand, thereby affecting the overall aerodynamic performance of the impeller, and on the other hand, the flow separation of the rear edge part of the blades can not be improved, and the noise problem can also be caused. Secondly, because the centrifugal fan quickly deflects by 90 degrees after axially feeding air and radially enters the impeller flow channel, airflow at the front edge of the blade is more easily turbulent at the tip of the blade, and further adverse effects such as vortex separation of the airflow in the impeller flow channel are caused.

SUMMERY OF THE UTILITY MODEL

The first technical problem to be solved by the utility model is to provide a blade for a centrifugal fan, which can effectively reduce the noise problem on the basis of ensuring that the blade has enough pressure rise, aiming at the current situation of the prior art.

The second technical problem to be solved by the utility model is to provide a blade for a centrifugal fan, which can be matched with the air inlet condition of an impeller so as to realize targeted noise reduction, aiming at the current situation of the prior art.

The third technical problem to be solved by the present invention is to provide a centrifugal fan impeller using the above-mentioned blade, aiming at the current situation of the prior art.

The fourth technical problem to be solved by the present invention is to provide a centrifugal fan using the above impeller in view of the current situation of the prior art.

The technical scheme adopted by the utility model for solving the first problem technical problem is as follows:

a blade for a centrifugal fan impeller comprises a blade body, wherein at least two through holes penetrating from a pressure surface to a suction surface are arranged on the blade body, and each through hole comprises a first hole arranged adjacent to the front edge of the blade body and a second hole arranged adjacent to the rear edge of the blade body.

In order to improve the noise reduction effect at the front edge and the rear edge of the blade body, at least two first holes are arranged in sequence along the length direction of the blade body; the second holes are at least two and are sequentially arranged along the length direction of the blade body.

In order to further ensure the noise reduction effect, the cross section of the blade body is arc-shaped, the total wrap angle of the blade body is A, the wrap angle between the front edge of the blade body and the straight line where the first holes are located is alpha, the wrap angle between the rear edge of the blade body and the straight line where the second holes are located is beta, wherein the A is more than or equal to 70 degrees and less than or equal to 130 degrees, the alpha is more than or equal to 10 degrees and less than or equal to 30 degrees, and the beta is more than or equal to 10 degrees and less than or equal to 20 degrees.

If the diameter of the through hole is too large, the air flow passing through the through hole will have an adverse effect on the air flow at a large distance from the blade surface, and if the diameter of the through hole is too small, the air flow passing through the through hole will only have an effect on the air flow near the surface, which is not enough to suppress the generation of vortices, and therefore the diameter of the through hole needs to be designed reasonably, where D is 0.8mm or more and 1.5mm or less.

As an improvement, the area of the pressure surface of the blade body is marked as M, the sum of the areas of the through holes on the pressure surface of the blade body is marked as M, and M/M is more than or equal to 0.04 and less than or equal to 0.08.

The value of M/M is a perforation coefficient, the perforation coefficient is increased, the noise reduction value is increased, the resistance is reduced, the lift coefficient is reduced, when the perforation coefficient M/M is 0.04-0.08, the influence on the aerodynamic performance is small, and the noise reduction effect is good.

The technical scheme adopted by the utility model for solving the second problem technical problem is as follows:

the distance between the adjacent first holes and the distance between the adjacent second holes are gradually increased along the length direction of the blade body.

Adjacent interval between the first hole and adjacent interval between the second hole change can carry out reasonable design according to centrifugal fan's operating condition, and as an preferred embodiment, adjacent interval between the first hole and adjacent interval between the second hole all are arranged by arithmetic progression, and the value range of tolerance d is 3mm ~ 5 mm.

The technical scheme adopted by the utility model for solving the third problem technical problem is as follows:

the centrifugal fan impeller comprises a front disc and a rear disc which are oppositely arranged at intervals, the blades are sequentially distributed between the front disc and the rear disc at intervals along the circumferential direction, the first end of each blade body is correspondingly connected with the front disc, and the second end of each blade body is correspondingly connected with the rear disc.

The technical scheme adopted by the utility model for solving the fourth problem technical problem is as follows: a centrifugal fan using the centrifugal fan impeller.

Compared with the prior art, the utility model has the advantages that:

1. the first hole is arranged in the area of the blade body, which is adjacent to the front edge of the blade, and the second hole is arranged in the area of the blade body, which is adjacent to the rear edge of the blade, so that on one hand, partial airflow can directly flow to the suction surface from the pressure surface, and further, the generation of vortex is reduced and inhibited; on the other hand, because the middle area of the blade is not provided with the through hole, the blade can be ensured to have enough pressure rise, and the pneumatic performance is not lost.

2. By adopting the noise reduction scheme of perforating the front edge area and the rear edge area of the blade, the noise reduction cost is not increased, the limitation of the actual structural space is avoided, and the purposes of reducing the aerodynamic noise of the fan and reducing the accumulation of oil stains on the pressure surface of the blade are achieved only by designing reasonable perforation parameters under the condition of not changing the performance of the fan.

Drawings

FIG. 1 is a perspective view of a blade according to an embodiment of the present invention;

FIG. 2 is a front view (pressure side angle facing) of a blade according to an embodiment of the utility model;

FIG. 3 is a cross-sectional view taken at A-A of FIG. 2;

fig. 4 is a schematic perspective view of an impeller according to an embodiment of the present invention.

Detailed Description

The utility model is described in further detail below with reference to the accompanying examples.

Referring to fig. 1-4, a centrifugal fan impeller includes a front disk 21, a rear disk 22 and a plurality of blades, the front disk 21 and the rear disk 22 are arranged at intervals, and the plurality of blades are sequentially arranged between the front disk 21 and the rear disk 22 at intervals along a circumferential direction. The blade comprises blade bodies 10 having a first end 13 and a second end 14, the first end 13 of each blade body 10 being connected to a front disc 21 and the second end 14 of each blade body 10 being connected to a rear disc 22.

Referring to fig. 1, the blade body 10 has a front edge 11, a rear edge 12, a pressure surface 17 and a suction surface 18, wherein the front edge 11 corresponds to an air inlet edge of the blade body 10, the rear edge 12 corresponds to an air outlet edge of the blade body 10, the pressure surface 17 of the blade body 10 refers to a side surface facing an incoming flow to generate pressure, i.e., a working surface, and the suction surface 18 of the blade body 10 refers to a side surface facing away from the incoming flow, i.e., a non-working surface.

With continued reference to fig. 1, the blade body 10 is provided with a through hole extending from the pressure surface 17 to the suction surface 18. The through holes include a first hole 15 arranged adjacent to the leading edge 11 of the blade body 10 and a second hole 16 arranged adjacent to the trailing edge 12 of the blade body 10, and specifically, the first hole 15 and the second hole 16 are each provided in plurality and are arranged at intervals in sequence along the length direction of the blade body 10.

Referring to fig. 2, an important point of the blade body 10 of the present embodiment is that the distance between the adjacent first holes 15 on the blade body 10 and the distance between the adjacent second holes 16 on the blade body 10 are gradually increased along the length direction of the blade body 10. As a preferable scheme, the distance between the adjacent first holes 15 and the distance between the adjacent second holes 16 are arranged in an arithmetic progression, and the range of the tolerance d is 3mm to 5 mm. As shown in FIG. 2, the interval between adjacent first holes 15 is denoted as a_n(n-1, 2, 3 … …) wherein d-a is the tolerance_n-a_n-1Wherein, the same reason for the change of the distance between the adjacent second holes 16 is not repeated.

Referring to fig. 3, the cross section of the blade body 10 of the present embodiment is arc, and the total wrap angle of the blade body 10 is a, wherein the value range of the total wrap angle a is: a is more than or equal to 70 degrees and less than or equal to 130 degrees. The first holes 15 on the blade body 10 of the present embodiment are in a row, the straight line on which each first hole 15 is located is substantially parallel to the leading edge 11 of the blade, wherein the wrap angle α between the leading edge 11 of the blade body 10 and the straight line on which each first hole 15 is located is 10 ° or more and 30 ° or less, and similarly, the second holes 16 on the blade body 10 of the present embodiment are also in a row, the straight line on which each second hole 16 is located is substantially parallel to the trailing edge 12 of the blade, the wrap angle between the trailing edge 12 of the blade body 10 and the straight line on which each second hole 16 is located is β and the wrap angle β is 10 ° or more and 30 ° or less.

If the diameter of the through hole is too large, the air flow passing through the through hole will adversely affect the air flow at a large distance from the blade surface, and if the diameter of the through hole is too small, the air flow passing through the through hole will only affect the air flow near the surface, and will not sufficiently suppress the generation of vortex, therefore, the diameter of the through hole (including the first hole 15 and the second hole 16) on the blade body 10 in this embodiment should be designed reasonably, and the diameter of the through hole is D, wherein D is 0.8mm ≦ D ≦ 1.5 mm.

In addition, the area of the pressure surface 17 of the blade body 10 is marked as M, the sum of the areas of the through holes on the pressure surface 17 of the blade body 10 is marked as M, wherein M/M is more than or equal to 0.04 and less than or equal to 0.08. The value of M/M is a perforation coefficient, the perforation coefficient is increased, the noise reduction value is increased, the resistance is reduced, the lift coefficient is reduced, when the perforation coefficient M/M is 0.04-0.08, the influence on the aerodynamic performance is small, and the noise reduction effect is good.

The embodiment also relates to a centrifugal fan applying the centrifugal fan impeller.

On the basis of the above embodiments, other embodiments can be obtained by replacing and improving the related technical features. For example, the aperture of the first hole 15 and the aperture of the second hole 16 on the blade body 10 may be the same aperture, or may be different apertures, and may be designed reasonably according to specific practical conditions; similarly, the first holes 15 in the same row of the blade body 10 may have the same or different hole diameters, and the second holes 16 in the same row of the blade body 10 may have the same or different hole diameters; for another example, in the drawings of the present embodiment, only one row of through holes is provided on both the front edge 11 and the rear edge 12 of the blade body 10, and it is conceivable that the through holes on the front edge 11 or the rear edge 12 of the blade body 10 may be provided in two or more rows arranged in parallel.

Claims

1. The utility model provides a blade for centrifugal fan impeller, includes blade body (10), has arranged on this blade body (10) at least two from pressure face (17) to suction face (18) through-hole that runs through, its characterized in that: the through holes comprise a first hole (15) arranged adjacent to the leading edge (11) of the blade body (10) and a second hole (16) arranged adjacent to the trailing edge (12) of the blade body (10).

2. The blade for a centrifugal fan impeller according to claim 1, characterized in that:

the number of the first holes (15) is at least two, and the first holes are sequentially arranged along the length direction of the blade body (10);

the number of the second holes (16) is at least two, and the second holes are sequentially arranged along the length direction of the blade body (10).

3. The blade for a centrifugal fan impeller according to claim 1, characterized in that: the cross section of the blade body (10) is arc-shaped, the total wrap angle of the blade body (10) is A, the wrap angle between the front edge (11) of the blade body (10) and the straight line where the first holes (15) are located is alpha, the wrap angle between the rear edge (12) of the blade body (10) and the straight line where the second holes (16) are located is beta, wherein A is larger than or equal to 60 degrees and smaller than or equal to 130 degrees, alpha is larger than or equal to 10 degrees and smaller than or equal to 30 degrees, and beta is larger than or equal to 10 degrees and smaller than or equal to 20 degrees.

4. The blade for a centrifugal fan impeller according to claim 1, characterized in that: the diameter of the through hole is D, wherein D is more than or equal to 0.8mm and less than or equal to 1.5 mm.

5. The blade for a centrifugal fan impeller according to claim 1, characterized in that: the area of the pressure surface (17) of the blade body (10) is marked as M, the sum of the areas of the through holes on the pressure surface (17) of the blade body (10) is marked as M, wherein M/M is more than or equal to 0.04 and less than or equal to 0.08.

6. The blade for a centrifugal fan impeller according to any one of claims 2 to 5, wherein: the distance between the adjacent first holes (15) and the distance between the adjacent second holes (16) are gradually increased along the length direction of the blade body (10).

7. The blade for a centrifugal fan impeller according to claim 6, wherein: the distance between the adjacent first holes (15) and the distance between the adjacent second holes (16) are arranged in an arithmetic progression, and the value range of the tolerance d is 3-5 mm.

8. A centrifugal fan impeller to which the blade for a centrifugal fan impeller according to any one of claims 1 to 7 is applied, characterized in that: the novel blade comprises a front disc (21) and a rear disc (22) which are oppositely arranged at intervals, wherein the blades are sequentially distributed between the front disc (21) and the rear disc (22) at intervals along the circumferential direction, a first end (13) of each blade body (10) is correspondingly connected with the front disc (21), and a second end (14) of each blade body (10) is correspondingly connected with the rear disc (22).

9. A centrifugal fan applying a centrifugal fan impeller according to claim 8.