CN219220826U

CN219220826U - Blade for centrifugal fan impeller, centrifugal fan impeller and multi-wing centrifugal fan

Info

Publication number: CN219220826U
Application number: CN202222784462.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: 2022-10-21
Filing date: 2022-10-21
Publication date: 2023-06-20
Anticipated expiration: 2032-10-21

Abstract

The utility model relates to a blade for a centrifugal fan impeller, a centrifugal fan impeller and a multi-wing centrifugal fan, wherein the blade comprises a blade body, two side edges extending in the length direction of the blade body are respectively marked as a first side edge and a second side edge, the first side edge corresponds to an air inlet edge of the blade body, the second side edge corresponds to an air outlet edge of the blade body, the cross section of the blade body is an arc, and at least one side edge of the first side edge and the second side edge of the blade body is provided with a rectifying part which is smoothly connected with the blade body, and the cross section of the rectifying part is a straight line. According to the blade, the traditional single-arc blade is provided with the rectifying part with the straight cross section at the air inlet edge or the air outlet edge, so that the pneumatic performance is effectively improved, and the noise is reduced.

Description

Blade for centrifugal fan impeller, centrifugal fan impeller and multi-wing 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, the centrifugal fan impeller and a multi-wing centrifugal fan.

Background

Centrifugal fans, such as multi-wing centrifugal fans, are an important power device and are commonly applied to products such as range hoods, air conditioners and the like. Centrifugal fans typically include a volute and an impeller disposed within the volute, the impeller being a rotating component in the centrifugal fan that plays an important role in energy conversion and transfer in the fan. The inlet and outlet mounting angles of the blades are sensitive parameters affecting the performance of the fan. If the design of the inlet mounting angle of the blade is too small, an acceleration flow channel can not be obtained, and if the design is too large, the impact loss of the inlet of the blade can be increased; the increase of the outlet mounting angle of the blades can achieve the purposes of increasing the flow rate of the fan and improving the wind pressure, but on the other hand, the increase of the outlet mounting angle can increase the diffusion degree of the flow channel, thereby leading to the separation of an airflow boundary layer, increasing the diffusion loss and reducing the efficiency of the fan, so the outlet mounting angle of the blades is generally designed between 160 degrees and 175 degrees, and most of the blades only adopt single-arc straight blades which inevitably produce flow separation at She Daona and the outlet of the blade channel.

As the multi-wing centrifugal fan for the range hood operates in multiple gears and multiple working modes, the inlet mounting angle of the blades is designed to be 50-70 degrees according to different flowing states. However, since the gas flow inside the centrifugal fan does not have symmetry, it is impossible to eliminate all of such impact of She Daona. In order to solve the problem, under the condition of not increasing the outline dimension of the impeller, the blade profile of the multi-wing centrifugal fan is usually required to be designed, for example, chinese patent application No. CN202122811572.6 (issued to date: CN 216199226U) discloses a double-layer multi-wing centrifugal fan impeller, the section of the blade of the impeller comprises a first section of circular arc and a second section of circular arc, the first section of circular arc and the second section of circular arc are integrally formed, the inlet installation angle of the first section of circular arc is 40-60 degrees, and the outlet installation angle of the second section of circular arc is 150-170 degrees. By adopting the two-section arc design, the design of excessive arc sections can be reduced, unreasonable flow passages among blades are avoided, the separation loss generated by the attack angle is well inhibited, the effective flow area is increased, and the noise of the multi-wing centrifugal fan is reduced.

However, the middle blade of the above patent application has a certain disadvantage, because the multi-wing centrifugal fan blade generally has the characteristics of short flow channel and large curvature, and the blade structure adopting the two-section arc design also inevitably generates flow separation vortex and wake vortex at the tail edge of the outlet, especially the wake vortex falling off will affect the flow state in the downstream volute, so that the working efficiency of the multi-wing centrifugal fan is reduced, the noise is increased, and therefore, how to eliminate or weaken the vortex and separation in the flow state, further improving the working efficiency of the multi-wing centrifugal fan and reducing the noise are technical problems that need to be solved by those skilled in the art.

Disclosure of Invention

The first technical problem to be solved by the utility model is to provide a blade for a centrifugal fan impeller, which can effectively improve the fluid state of the front edge and/or the tail edge of the blade, reduce flow separation, improve the working efficiency of the centrifugal fan and reduce noise.

The second technical problem to be solved by the utility model is to provide a centrifugal fan impeller applying the blade aiming at the current state of the art.

The utility model aims to solve the third technical problem and provides a multi-wing centrifugal fan applying the impeller aiming at the current state of the art.

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

the utility model provides a blade for centrifugal fan impeller, includes the blade body, marks as first side and second side respectively at two sides that extend on this blade body length direction, first side corresponds the edge of admitting air of blade body, the second side corresponds the edge of giving vent to anger of blade body, the cross section of blade body is the circular arc, have the rectification portion that meets with this blade body smoothness on at least one side in first side and the second side of blade body, the cross section of rectification portion is the straight line.

On the basis of a single circular arc blade, a tangent straight line section (namely a drainage part) is additionally arranged at the air inlet edge, so that the flow coefficient can be improved within a certain range, the air quantity is increased, however, the application effect cannot be achieved due to the fact that the straight line section of the front edge drainage part is too short, the inner diameter of an impeller can be reduced again when the straight line section of the front edge drainage part is too long, and the air quantity is influenced.

The tangent straight line section (namely the supercharging part) is additionally arranged at the air outlet edge, so that the pressure coefficient can be improved within a certain range, the air pressure is improved, and when the straight line section of the supercharging part is too short, the application supercharging effect cannot be achieved; when the straight line section of the supercharging part is overlong, the cross section area of the outlet of the lobule passageway can be reduced, and the air quantity is influenced, so that the length of the cross section of the straight line section of the supercharging part should be reasonably valued, the rectifying part extending outwards from the second side edge of the blade body is recorded as a tail edge supercharging part, and the length m of the straight line section corresponding to the cross section of the tail edge supercharging part is more than or equal to 2mm and less than or equal to 5mm.

In order to better improve the working efficiency of the fan, the radius of the circle section corresponding to the cross section of the blade body is R, wherein R is more than or equal to 11mm and less than or equal to 15mm.

Preferably, the inlet mounting angle of the blade body is denoted as β1, and the outlet mounting angle is denoted as β2, wherein β1 is greater than or equal to 50 ° and less than or equal to 70 °; beta 2 is more than or equal to 160 degrees and less than or equal to 175 degrees.

In order to facilitate processing and reduce production cost, the thickness of the blade body is equal to that of the rectifying part. Preferably, the blade body and the rectifying part are integrated,

the utility model solves the second technical problem by adopting the technical proposal that:

the centrifugal fan impeller comprises a front disc, a rear disc and blades, wherein the front disc and the rear disc are arranged in a relative mode, the blades are distributed between the front disc and the rear disc at intervals along the circumferential direction, and the blades adopt the blades.

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

the multi-wing centrifugal fan comprises a volute and an impeller arranged in the volute, wherein the impeller adopts the centrifugal fan impeller.

Compared with the prior art, the utility model has the advantages that: according to the blade, the traditional single-arc blade is provided with the rectifying part with the straight cross section at the air inlet edge or the air outlet edge, so that the pneumatic performance is effectively improved, the noise is reduced, wherein the pressure pulsation generated by the airflow impact at the front edge of the blade can be reduced after the rectifying part is arranged at the front edge of the blade, the generation and development of swirling flow in the inter-blade flow channel are effectively inhibited, and the separation flow of the blade channel outlet is reduced; and the rectification part arranged at the rear edge of the blade can reduce the unsteady interaction between the tail flow and the volute, so that the performance of the centrifugal fan with the impeller is improved, and the noise is reduced. The blade is different from the traditional single-arc blade which is bent and extended along the curvature of the front edge and the tail edge, so that the inlet angle and the outlet angle of the blade are not caused, the central angle of the blade is not changed, and particularly, the outlet mounting angle of the blade is not increased due to the extension of the tail edge, the blocking coefficient of a blade path and the outlet is increased, the pulsation of airflow wake is enhanced, and the efficiency of a fan is deteriorated under a low-resistance working condition.

Drawings

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

FIG. 2 is a top view of the blade shown in FIG. 1;

FIG. 3 is a front view of the blade shown in FIG. 1;

FIG. 4 is a schematic perspective view of a centrifugal fan impeller according to an embodiment of the present utility model;

FIG. 5 is a schematic perspective view of a multi-wing centrifugal fan according to an embodiment of the present utility model;

FIG. 6 is a graph comparing simulated pressure clouds of a conventional single arc blade and a blade employing an embodiment of the present utility model; (the left side is a traditional single arc blade, and the right side is a blade of the embodiment);

FIG. 7 is a flow chart comparing a conventional single arc blade and an impeller flow path using a blade according to an embodiment of the present utility model; (the left side is a traditional single arc blade, and the right side is a blade of the embodiment);

fig. 8 is a graph comparing performance curves of a range hood using a conventional single circular arc blade and using an embodiment of the present utility model.

Detailed Description

The utility model is described in further detail below with reference to the embodiments of the drawings.

In the description and claims of the present utility model, terms indicating directions, such as "front", "rear", "upper", "lower", "left", "right", "side", "top", "bottom", etc., are used to describe various example structural parts and elements of the present utility model, but these terms are used herein for convenience of description only and are determined based on the example orientations shown in the drawings. Because the disclosed embodiments of the utility model may be arranged in a variety of orientations, the directional terminology is used for purposes of illustration and is in no way limiting, such as "upper" and "lower" are not necessarily limited to being in a direction opposite or coincident with the direction of gravity.

Referring to fig. 1 to 3, there is shown a blade for a centrifugal fan impeller, the blade comprising a blade body 10, the blade body 10 being an arc blade of equal thickness, i.e. the cross section of the blade body 10 being an arc. Two sides extending in the length direction of the blade body 10 are respectively denoted as a first side 11 and a second side 12, wherein the first side 11 corresponds to an inlet edge of the blade body 10 and the second side 12 corresponds to an outlet edge of the blade body 10.

The first side 11 and the second side 12 of the blade body 10 of the present embodiment each have a rectifying portion smoothly connected to the blade body 10, specifically, the rectifying portion extending outward from the first side 11 of the blade body 10 is denoted as a leading edge drainage portion 13, and the rectifying portion extending outward from the second side 12 of the blade body 10 is denoted as a trailing edge supercharging portion 14. The cross sections of the leading edge drainage portion 13 and the trailing edge increasing portion of this embodiment are straight lines, which are tangent to both ends of the circular arc corresponding to the cross section of the blade body 10. The leading edge flow guiding portion 13 and the trailing edge pressure increasing portion 14 of the present embodiment are also of a sheet structure with equal thickness, wherein the thickness of the blade body 10, the thickness of the leading edge flow guiding portion 13 and the thickness of the trailing edge pressure increasing portion 14 are all equal, and in a preferred embodiment, the blade body 10, the leading edge flow guiding portion 13 and the trailing edge pressure increasing portion 14 are integrally formed as a single piece.

The radius of the circle segment corresponding to the cross section of the blade body 10 of the present embodiment is R, where R is 11mm or less and 15mm or less, the length n of the straight line segment corresponding to the cross section of the leading edge drainage portion 13 is 1mm or less and 3mm or less, and the length m of the straight line segment corresponding to the cross section of the trailing edge supercharging portion 14 is 2mm or less and 5mm or less. The inlet mounting angle of the blade body 10 is denoted as β1 and the outlet mounting angle is denoted as β2, wherein 50 ° - β1-70 °,160 ° - β2-175 °, preferably 65 ° - β1-70 °,165 ° - β2-173 °.

The common single-arc blade profile is determined by 6 parameters, namely an impeller inner diameter D1, an impeller outer diameter D2, an inlet mounting angle beta 1, an outlet mounting angle beta 2, a blade arc radius R and a blade arc center angle alpha, wherein the 6 parameters are mutually related, and a unique blade profile can be determined through 4 parameters. In general, in the actual design process of the blade profile of the multi-wing centrifugal fan, the circular arc radius R is not a decisive parameter and can be determined by other parameters, so that in order to reduce the variable and facilitate the same ratio, in the embodiment, when the blade is designed, the impeller outer diameter parameter D2 can be fixed, the influence of the impeller outer diameter dimension D2 on the performance of the fan is eliminated, on the basis, the blade inlet mounting angle β1 and the impeller inner diameter D1 are selected as design parameters, the circular arc radius R of the blade is determined by the sectional design of the blade profile, and finally the blade profile is drawn.

In the embodiment, the blade is provided with a rectifying part with a straight cross section at the front edge (i.e. an air inlet edge) or the rear edge (i.e. an air outlet edge) of the traditional single-arc blade, so that the aerodynamic performance is effectively improved, the noise is reduced, the pressure pulsation generated by the airflow impact at the front edge of the blade can be reduced, the generation and development of swirling flow in the flow channels between the blades are effectively inhibited, and the separation flow of the outlet of the blade channels is reduced; the rectifying part arranged at the rear edge of the blade can reduce unsteady interaction between the tail flow and the volute 30, so that the performance of the centrifugal fan with the impeller is improved, and noise is reduced.

As shown in fig. 4, the present embodiment also relates to a centrifugal fan impeller using the above-mentioned blades 1, which impeller comprises a front disk 21 and a rear disk 22 arranged opposite to each other, and the above-mentioned blades related in sections are circumferentially spaced between the front disk 21 and the rear disk 22. As further shown in fig. 5, the present utility model also relates to a multi-wing centrifugal fan, which comprises a volute 30 and an impeller 2 disposed in the volute 30, wherein the impeller 2 adopts the impeller structure shown in fig. 4.

From the basic theory of aeroacoustics, it can be known that the intensity of the aerodynamic sound source mainly depends on the static pressure pulsation intensity of the fluid and the solid wall surface, and therefore, the intensity of the aerodynamic noise source can be known by analyzing the static pressure pulsation intensity in the flow field. The volute tongue is one of the main parts of the fan aerodynamic noise, particularly discrete noise. As can be seen from fig. 6, compared with the centrifugal fan with the vane designed by the embodiment in a sectional manner, the centrifugal fan with the conventional single circular arc vane on the left side has a larger static pressure gradient at the wall surface of the volute tongue (the position where the oval mark is located in the figure) and has the highest static pressure value near the top of the volute tongue, so that it can be considered that the reduction of the static pressure pulsation can reduce the aerodynamic noise of the centrifugal fan.

The volute tongue mainly plays a role in gas diversion in the centrifugal fan structure, most of gas is discharged from the outlet of the volute 30, and the small part of gas flows back into the volute 30. When the range hood operates in a pipe network, the high resistance can reduce the flow rate of the outlet of the volute 30, so that the gas flowing back into the volute 30 is increased. As can be seen from fig. 7, the centrifugal fan using the vane of the present embodiment on the right side has reduced backflow of air in the impeller flow passage compared to the conventional vane on the left side. Wherein, part of the air flows back in the flow passage area of the left mark 1, and no air flows back in the flow passage area of the right mark 1, so that the resistance of the impeller is improved, and the air quantity of the range hood is improved within a certain range.

As can be seen from fig. 8, compared with a range hood using a conventional vane, the range hood using the vane of the present embodiment has pneumatic performance improved by about 0.5% to 1% under different resistance conditions, and full-pressure internal efficiency improved by about 1% to 2%. In addition, the range hood using the blade of the embodiment is compared with the range hood using the traditional blade, the rotating speed can be reduced by 15-30 rpm under different resistance working conditions, and the noise can be reduced by 0.2-0.5 dB.

It is conceivable that the fluid state of the blade leading edge and/or trailing edge can be improved to a certain extent, flow separation can be reduced, the working efficiency of the centrifugal fan can be improved, and noise can be reduced by providing the leading edge drainage portion 13 with a straight corresponding cross section only at the inlet edge of the blade body 10, or providing the trailing edge addition portion with a straight corresponding cross section only at the outlet edge of the blade body 10. Of course, the preferred scheme is to adopt the preferred blade structure that sets up the rectification portion at the inlet edge and the edge of giving vent to anger of blade body 10, can reduce the pressure pulsation that the blade leading edge produced because of the air current impact behind the rectification portion that the blade leading edge set up, effectively restrain the generation and the development of the interior vortex flow of inter-leaf runner to reduce the separation flow of blade way export, on this basis, the rectification portion that the blade trailing edge set up can reduce the unsteady interact of tail flow and spiral case 30, thereby make the centrifugal fan performance that is used with the impeller promote, and the noise reduces.

Claims

1. The utility model provides a blade for centrifugal fan impeller, includes blade body (10), marks as first side (11) and second side (12) respectively at two sides that extend in this blade body (10) length direction, first side (11) correspond the edge of admitting air of blade body (10), second side (12) correspond the edge of giving vent to anger of blade body (10), its characterized in that: the cross section of the blade body (10) is an arc, at least one side edge of the first side edge (11) and the second side edge (12) of the blade body (10) is provided with a rectifying part which is smoothly connected with the blade body (10), and the cross section of the rectifying part is a straight line.

2. The blade for a centrifugal fan impeller according to claim 1, wherein: the rectifying part extending outwards from the first side edge (11) of the blade body (10) is named as a front edge drainage part (13), and the length n of a straight line section corresponding to the cross section of the front edge drainage part (13) is more than or equal to 1mm and less than or equal to 3mm.

3. The blade for a centrifugal fan impeller according to claim 1 or 2, wherein: the rectifying part extending outwards from the second side edge (12) of the blade body (10) is called a tail edge pressurizing part (14), and the length m of a straight line section corresponding to the cross section of the tail edge pressurizing part (14) is more than or equal to 2mm and less than or equal to 5mm.

4. A centrifugal fan impeller blade according to claim 3, wherein: the radius of the circle segment corresponding to the cross section of the blade body (10) is R, wherein R is more than or equal to 11mm and less than or equal to 15mm.

5. The blade for a centrifugal fan impeller according to claim 4, wherein: the inlet mounting angle of the blade body (10) is denoted as beta 1, and the outlet mounting angle is denoted as beta 2, wherein beta 1 is more than or equal to 50 degrees and less than or equal to 70 degrees; beta 2 is more than or equal to 160 degrees and less than or equal to 175 degrees.

6. A centrifugal fan impeller blade according to claim 3, wherein: the thickness of the blade body (10) is equal to the thickness of the rectifying part.

7. The blade for a centrifugal fan impeller according to claim 6, wherein: the blade body (10) and the rectifying part are integrated.

8. A centrifugal fan impeller comprising a front disc (21) and a rear disc (22) which are arranged in opposition and blades which are distributed between the front disc (21) and the rear disc (22) at intervals along the circumferential direction, characterized in that: the blade according to any one of claims 1 to 7.

9. The utility model provides a many wings centrifugal fan, includes spiral case (30) and locates impeller in spiral case (30), its characterized in that: the impeller employs the centrifugal fan impeller of claim 8.