CN215830794U - Centrifugal fan impeller and centrifugal fan applying same - Google Patents

Abstract

The utility model relates to a centrifugal fan impeller and a centrifugal fan applying the same, comprising: the front disc is provided with an air inlet; a rear disc disposed opposite to the front disc; the blades are arranged between the front disc and the rear disc and are distributed along the circumferential direction of the front disc, and each blade is provided with an air inlet edge close to the air inlet in the radial direction of the impeller and an air outlet edge far away from the air inlet; the air inlet edge of blade has at length direction relative first end and second end, the first end on air inlet edge with the head disk is connected, the second end on air inlet edge with the back disk is connected, the contour line on air inlet edge is for holding the protruding spline curve of concave back earlier from first end to second. The air inlet edge of the blade adopts the structural design of concave first and convex second, so that the air inlet resistance can be effectively reduced, the separation vortex generated on the front edge of the blade can be avoided, the aerodynamic noise is reduced, the airflow deflection capability of the root part of the front edge of the blade can be effectively guaranteed, and the airflow flowing loss is reduced.

Description

Centrifugal fan impeller and centrifugal fan applying same

Technical Field

The utility model relates to the technical field of centrifugal fan impellers, in particular to a centrifugal fan impeller and a centrifugal fan applying the same.

Background

The centrifugal fan is a common air supply device and is widely applied to products such as dust collectors, range hoods, air conditioners and the like. The centrifugal fan is configured to rotate a plurality of blades around an axial direction by a motor and to blow air radially outward. The working efficiency of the existing centrifugal fan blade is generally low, mainly because the resistance generated by the blades of the centrifugal fan blade is large when the blades rotate, a large part of energy is used for overcoming the pressure difference resistance. And because of the existence of pressure difference resistance, the airflow is easy to generate secondary flow and separation phenomena at the inlet of the centrifugal fan blade (namely the front edge of the centrifugal fan blade), so that vortex noise is generated, the noise and power consumption level of the centrifugal fan are higher, and the efficiency of the centrifugal fan is limited.

Therefore, the chinese patent application with the application number CN201610503560.8 (with the publication number CN106015090A) discloses a centrifugal fan blade, which comprises a front disc, a rear disc and a plurality of fan blades, wherein the front disc is provided with an air inlet; an air outlet is arranged between the rear disc and the front disc; the blades are uniformly distributed between the front disc and the rear disc; wherein the front edge of the blade is designed into the shape of the outer edge of the bird wing; the airflow enters the centrifugal fan from the air inlet, enters the flow channel through the front edge of the blade, and then flows out of the air outlet through the rear edge of the blade. The leading edge of the blade has a first end and a second end; the first end is a leading edge blade root close to the rear disc, and the second end is a leading edge blade top close to the front disc; the shape of the outer edge of the bird-like wing is in a shape of a concave curve and a convex curve from the root of the leading edge blade to the top of the leading edge blade in sequence.

The centrifugal fan blade structure in the patent also has certain disadvantages, firstly, for the blade of the centrifugal fan, the front edge part of the blade adjacent to the air inlet is the place with the most serious impact of the air inlet flow, although the convex structure in the patent plays a role of guiding flow to a certain extent and reduces the air inlet resistance, when the blade is impacted by the high speed of the air flow, the acceleration in the boundary layer of the convex part is still high, the flowing of the boundary layer is not constant, and the boundary layer is easy to separate from the blade, thereby leading to the larger noise of the air flow; secondly, the blade in this patent designs into the structure of indent for blade leading edge root, and it has saved blade material to a certain extent, nevertheless, also because the structure of indent of blade root for the deflection ability of blade leading edge root portion air current reduces, produces the separation vortex easily, has increased the flow loss of air current here.

SUMMERY OF THE UTILITY MODEL

The first technical problem to be solved by the utility model is to provide a centrifugal fan impeller which can effectively reduce air inlet resistance, avoid separation vortex from being generated at the front edge of a blade and further reduce aerodynamic noise, aiming at the current situation of the prior art.

The second technical problem to be solved by the utility model is to provide a centrifugal fan impeller which can effectively ensure the airflow deflection capability of the root part of the front edge of the blade so as to reduce the airflow flow loss, aiming at the current situation of the prior art.

The third technical problem to be solved by the present invention is to provide an impeller of a centrifugal fan and a centrifugal fan using the same, which are directed to the current situation of the prior art.

The technical solution adopted by the present invention to solve any one of the first technical problem and the second technical problem is: a centrifugal fan impeller comprising:

the front disc is provided with an air inlet;

a rear disc disposed opposite to the front disc;

the blades are arranged between the front disc and the rear disc and are distributed at intervals along the circumferential direction of the front disc, and each blade is provided with an air inlet edge close to the air inlet in the radial direction of the impeller and an air outlet edge far away from the air inlet;

the air inlet edge of blade has at length direction relative first end and second end, the first end on air inlet edge with the head disk is connected, the second end on air inlet edge with the back disk is connected, the contour line on air inlet edge is concave earlier the protruding spline curve in back to the second end from the first end.

As an improvement, the contour line of the air inlet edge comprises an inner concave section and an outer convex section which are sequentially connected from a first end to a second end, the arc length of the inner concave section is smaller than that of the outer convex section, and the curvature of the outer convex section is larger than that of the inner concave section. The structure design enables the air flow to obviously accelerate flow in the concave section, reduces local static pressure, and then decelerates flow after flowing through the large-area convex section, the branch of the horseshoe vortex pressure surface is obviously stretched, so that the development of the branch of the horseshoe vortex pressure surface is delayed, the branch of the pressure surface is promoted to flow downstream, the acting time of the branch on a regeneration boundary layer is reduced, the boundary layer cannot be separated under the high-speed impact of the air inflow and is attached to the front edge, the boundary layer is transited to a turbulent flow state from a laminar flow state, the generation of a separation vortex is effectively inhibited, and the noise reduction effect is achieved.

The concave section can adopt various concave curve structures, and preferably, in order to better guide airflow and reduce airflow impact, the concave section is a parabola or an elliptic arc line.

In order to ensure that the airflow smoothly enters the blade channel at the air inlet front edge, the height of the blade is gradually reduced from the air inlet edge to the air outlet edge.

In order to be connected with preceding dish and back plate, the blade has first side and second side in the direction of height, the outline line of first side includes certainly first straight line segment and arc segment that air inlet edge to air-out edge connected gradually, the first straight line segment of first side with preceding dish is connected, the outline line of second side is the second straightway, and with the back plate is connected.

For better flow guidance, the cross section of the blades in the radial direction of the impeller is arc-shaped.

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

Compared with the prior art, the utility model has the advantages that: the air inlet edge of the blade of the centrifugal fan impeller adopts a concave-convex structure, in the running process of the impeller, the concave part close to the air inlet accelerates airflow flow firstly, so that airflow shock waves are attached to the air inlet front edge, the initial laminar boundary flow is rapidly converted into turbulent boundary flow within a short distance from the air inlet front edge of the blade, the acceleration of the boundary layer flow is kept low, the flow of the turbulent boundary layer is constant, the blade is not easy to separate, and the airflow noise is reduced. On the other hand, the design of the upper convex part of the front edge of the blade ensures that the root part (the connecting position with the rear disc) of the blade has a certain upper convex area, so that the branch of the pressure surface of the horseshoe vortex is obviously stretched, the development of the branch of the pressure surface of the horseshoe vortex is delayed, the branch has stronger separation resistance, and the generation of separation vortex is effectively inhibited, so that the deflection capability of airflow in the root area of the blade is improved, the mutual friction and mixing between the branch and a main flow are reduced, the separation vortex in a channel is obviously eliminated, the flow field in the whole area is effectively improved, and the flow loss in the root area of the blade is reduced.

Drawings

FIG. 1 is a schematic perspective view of an embodiment of the present invention;

FIG. 2 is a schematic perspective view of the front panel of FIG. 1 with the front panel hidden;

FIG. 3 is a schematic perspective view of a blade according to an embodiment of the present invention;

FIG. 4 is a schematic perspective view of another angle of a blade according to an embodiment of the present invention;

FIG. 5 is a front view of a blade of an embodiment of the present invention.

Detailed Description

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

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present invention and to simplify the description, but are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and that the directional terms are used for purposes of illustration and are not to be construed as limiting, for example, because the disclosed embodiments of the present invention may be oriented in different directions, "lower" is not necessarily limited to a direction opposite to or coincident with the direction of gravity. Furthermore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

Referring to fig. 1 to 5, a centrifugal fan impeller includes a front disk 10, a rear disk 11, and blades 20, wherein an air inlet 100 is formed in a middle region of the front disk 10, and the rear disk 11 is disposed opposite to the front disk 10. The blades 20 are plural and are spaced apart in the circumferential direction of the front disk 10. The gap between any adjacent two of the blades 20 forms a vane passage for the airflow to flow out radially. The external air flow enters through the air inlet 100 along the axial direction of the impeller, and enters the blade channel under the centrifugal action of the blades 20, and is thrown out along the radial direction of the impeller.

Referring to fig. 3 to 5, each of the blades 20 of the present embodiment has an air inlet edge 21 adjacent to the air inlet 100 and an air outlet edge 22 distant from the air inlet 100 in a radial direction of the impeller. The air inlet edge 21 of the vane 20 has a first end 211 and a second end 212 opposite to each other in a length direction, wherein the first end 211 of the air inlet edge 21 is connected to the front plate 10, the second end 212 of the air inlet edge 21 is connected to the rear plate 11, and a contour line of the air inlet edge 21 is a spline curve which is concave first and convex second from the first end 211 to the second end 212. Specifically, the contour line of the air intake edge 21 includes an inner concave section 213 and an outer convex section 214 connected in sequence from the first end 211 to the second end 212, wherein the arc length of the inner concave section 213 is smaller than the arc length of the outer convex section 214, specifically, the inner concave section 213 may be a parabola or an elliptic arc, and when the inner concave section 213 is an elliptic arc, the ratio of the semi-short axis to the semi-long axis of the blade 20 is less than or equal to 1/4. More specifically, the curvature of the convex section 214 is larger than that of the concave section 213, that is, the convex section 214 is more gentle than the concave section 213. The structural design enables the air flow to obviously accelerate flow in the concave section 213, reduces local static pressure, and then decelerates flow after flowing through the large-area convex section 214, the pressure surface branch of the horseshoe vortex is obviously stretched, so that the development of the pressure surface branch of the horseshoe vortex is delayed, the pressure surface branch is promoted to flow downstream, the acting time of the pressure surface branch on a regeneration boundary layer is reduced, the boundary layer cannot be separated under the high-speed impact of the air inflow and is attached to the front edge, the boundary layer is transited from a laminar flow state to a turbulent flow state, the generation of a separation vortex is effectively inhibited, and the noise reduction effect is achieved. In addition, the radial cross-section of blade 20 is the arc, and, the incline direction of each blade 20 is unanimous, makes the blade path that forms between two adjacent blades 20 also be the arc correspondingly from this, has made things convenient for the air current to carry out the water conservancy diversion better, has effectively improved the static pressure.

Referring to fig. 4, the blade 20 of the present embodiment has a first side 23 and a second side 24 in the height direction, wherein the height H of the blade 20 gradually decreases from the air inlet edge 21 to the air outlet edge 22, that is, the distance between the first side 23 and the second side 24 of the blade 20 gradually decreases from the air inlet edge 21 to the air outlet edge 22, so that the height (that is, the size in the front-back direction) of the blade duct formed between two adjacent blades 20 can be gradually reduced, and the airflow can be ensured to smoothly enter the blade duct at the air inlet front edge. More specifically, the contour line of the first side 23 includes a first straight line segment 231 and an arc line segment 232 which are sequentially connected from the air inlet edge 21 to the air outlet edge 22, the first straight line segment 231 of the first side 23 is connected with the front disk 10, and the contour line of the second side 24 is a second straight line segment 241 and is connected with the rear disk 11.

The air inlet edge of the blade 20 of the centrifugal fan impeller of the embodiment adopts a concave-convex structure, and the concave part close to the air inlet 100 is arranged, so that the air flow is accelerated firstly in the running process of the impeller, the air impact wave is attached to the air inlet front edge, the initial laminar boundary flow is rapidly converted into turbulent boundary flow in a short distance from the air inlet front edge of the blade 20, the acceleration of the boundary layer flow is kept low, the flow of the turbulent boundary layer is constant, the turbulent boundary layer is not easy to separate from the blade 20, and the air flow noise is reduced. On the other hand, the design of the upper convex part on the front edge of the blade 20 enables the root of the blade 20 (the connecting position with the rear disc 11) to have a certain upper convex area, so that the branch of the horseshoe vortex pressure surface is obviously stretched, the development of the branch of the horseshoe vortex pressure surface is delayed, the horseshoe vortex pressure surface has stronger separation resistance, the generation of separation vortex is effectively inhibited, the deflection capability of airflow in the root area of the blade 20 is improved, the mutual friction and mixing between the horseshoe vortex pressure surface and a main flow are reduced, the separation vortex in a channel is obviously eliminated, the flow field in the whole area is effectively improved, and the flow loss in the root area of the blade 20 is reduced.

Claims (7)

1. A centrifugal fan impeller comprising:

a front plate (10) having an air inlet (100);

a rear disc (11) arranged opposite to the front disc (10);

the blades (20) are arranged between the front disc (10) and the rear disc (11) and are distributed at intervals along the circumferential direction of the front disc (10), and each blade (20) is provided with an air inlet edge (21) close to the air inlet (100) in the radial direction of the impeller and an air outlet edge (22) far away from the air inlet (100);

the method is characterized in that: the air inlet edge (21) of blade (20) has at length direction relative first end (211) and second end (212), the first end (211) of air inlet edge (21) with front disc (10) are connected, the second end (212) of air inlet edge (21) with back dish (11) are connected, the contour line of air inlet edge (21) is concave-convex spline curve after first from first end (211) to second end (212).

2. The centrifugal fan impeller of claim 1, wherein: the contour line of air inlet edge (21) includes from first end (211) to second end (212) interior concave section (213) and convex section (214) that connect gradually, the arc length of interior concave section (213) is less than the arc length of convex section (214), and the camber of convex section (214) is greater than the camber of interior concave section (213).

3. The centrifugal fan impeller of claim 2, wherein: the concave section (213) is a parabola or an elliptic arc line.

4. The centrifugal fan impeller according to any one of claims 1-3, wherein: the height (H) of the blade (20) is gradually reduced from the air inlet edge (21) to the air outlet edge (22).

5. The centrifugal fan impeller of claim 4, wherein: blade (20) have first side (23) and second side (24) on the direction of height, the contour line of first side (23) includes certainly first straight line section (231) and the arc section (232) of evagination that air inlet edge (21) to air-out edge (22) connected gradually, first straight line section (231) of first side (23) with preceding dish (10) are connected, the contour line of second side (24) is second straightway (241), and with back dish (11) are connected.

6. The centrifugal fan impeller of claim 4, wherein: the section of the blade (20) in the radial direction of the impeller is arc-shaped.

7. A centrifugal fan applying a centrifugal fan impeller according to any one of claims 1-6.

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