Multi-wing centrifugal impeller and multi-wing centrifugal fan

Abstract

The utility model belongs to the technical field of centrifugal fans, and discloses a multi-wing centrifugal impeller and a multi-wing centrifugal fan, the multi-wing centrifugal impeller comprises an impeller disc, a plurality of blades and an impeller circular ring, the impeller disc and the impeller circular ring are connected to the two ends of the plurality of blades, each blade extends towards the circle center of the impeller disc, and the impeller circular ring is connected with the impeller disc. Each blade is provided with a front end and a rear end which are arranged at intervals in the radial direction of the impeller disc and a pressure face and a suction face which are arranged at intervals in the circumferential direction of the impeller disc, the front ends are arranged close to the circle center of the impeller disc, and sand dune type protrusions protruding towards the suction face are formed on the portions, close to the front ends, of the blades. The flow field uniformity and stability of the multi-wing centrifugal impeller are high, the flow channel shrinkage coefficient of the impeller is increased, and therefore the problem that the aerodynamic performance is poor when inlet impact loss and blade tail edge separation loss of airflow of an existing multi-wing centrifugal fan are large is solved.

Description

Technical Field

[0001] This utility model relates to the field of fan technology, and in particular to a multi-blade centrifugal impeller and a multi-blade centrifugal fan. Background Technology

[0002] Multi-blade forward-curved centrifugal fans are widely used in HVAC, electronic equipment cooling, and industrial ventilation systems due to their advantages such as high pressure coefficient, large flow coefficient, low noise, and compact structure. However, their aerodynamic performance still faces significant technical bottlenecks. A marked asymmetric flow phenomenon exists within the impeller channel. On the pressure side, the fluid exhibits stable, adherent flow along the profile, while on the suction side, flow separation occurs due to the excessive inlet angle of attack. Approximately 70% of the channel area forms large-scale separation vortices at the blade leading edge, resulting in significant flow losses.

[0003] Aerodynamic noise studies show that the shedding of separation vortices from the suction surface in the impeller back disk region is the main broadband noise source, and its sound pressure level is positively correlated with the flow field pulsation intensity. Numerical simulations show that when the separation vortex intensity is reduced by 30%, the 500Hz-2000Hz frequency band in the noise spectrum can be attenuated by 5dB-8dB. This indicates that optimizing flow field stability has both aeroacoustic and acoustic benefits.

[0004] Current designs generally employ uniform-thickness circular arc blade technology, which offers advantages such as low processing costs and flexible profile parameters. However, it suffers from significant aerodynamic drawbacks, including large inlet impact losses and severe blade trailing-edge separation losses, making it difficult to achieve optimal aerodynamic performance. While airfoil blade structures can reduce inlet impact losses and trailing-edge separation losses, the excessive camber and significant structural changes required to meet inlet and outlet angle requirements make it difficult to achieve optimal aerodynamic performance. Utility Model Content

[0005] The first objective of this invention is to provide a multi-bladed centrifugal impeller with high flow field uniformity and stability, which improves the flow channel contraction coefficient of the impeller, thereby improving the problem of poor aerodynamic performance caused by large airflow in existing multi-bladed centrifugal fans when the airflow has large inlet impact loss and blade trailing edge separation loss.

[0006] The second objective of this invention is to provide a multi-blade centrifugal fan, which has relatively small inlet impact loss and blade trailing edge separation loss, high flow field uniformity and stability, and superior aerodynamic performance.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] This utility model discloses a multi-blade centrifugal impeller, including an impeller disk, multiple blades, and an impeller ring. The impeller disk and the impeller ring are connected to both ends of the multiple blades. Each blade extends toward the center of the impeller disk. Each blade has a front end and a rear end spaced radially along the impeller disk, and a pressure surface and a suction surface spaced circumferentially along the impeller disk. The front end is located near the center of the impeller disk. The portion of the blade near the front end forms a dune-shaped protrusion protruding toward the suction surface. The dune-shaped protrusion is used to reduce the vortex formed by the airflow at the front end.

[0009] In some embodiments, in the direction from the front end toward the rear end, the dune-shaped protrusion includes a gradually widening segment and a gradually narrowing segment, with the larger end of the gradually widening segment facing the larger end of the gradually narrowing segment.

[0010] In some embodiments, the front end of the blade is formed with a tapered structure that gradually decreases in width.

[0011] In some embodiments, the maximum width of the dune-shaped protrusion is greater than the maximum width of the rear end, and the maximum width of the rear end is greater than the maximum width of the front end.

[0012] In some embodiments, the outer peripheral wall of the impeller ring is provided with a reinforcing structure extending axially along the impeller disk.

[0013] In some embodiments, the vertex of the front end is a, the highest point of the dune-shaped protrusion is b, the vertex of the rear end is c, the line connecting the vertex a of the front end and the vertex c of the rear end is the blade chord, the length of the blade chord is L1, and the distance between the highest point b of the dune-shaped protrusion and the vertex a of the front end along the length direction of the blade chord is L2. L1 and L2 satisfy the relationship: 1 / 8 ≤ L2 / L1 ≤ 1 / 2.

[0014] In some embodiments, the vertex of the front end is a, the highest point of the dune-shaped protrusion is b, the vertex of the rear end is c, the line connecting the vertex a of the front end and the vertex c of the rear end is the blade chord, the length of the blade chord is L1, and the distance between the highest point b of the dune-shaped protrusion and the vertex a of the front end is H1 in a direction perpendicular to the length of the blade chord. L1 and H1 satisfy the relationship: 1 / 6 ≤ H1 / L1 ≤ 3 / 4.

[0015] In some embodiments, the vertex of the front end is a, the highest point of the pressure surface is d, the vertex of the rear end is c, the line connecting the vertex a of the front end and the vertex c of the rear end is the blade chord, the length of the blade chord is L1, and the distance between the highest point d of the pressure surface and the vertex a of the front end along the length direction of the blade chord is L3. L1 and L3 satisfy the relationship: 1 / 5 ≤ L3 / L1 ≤ 1 / 2.

[0016] In some embodiments, the vertex of the front end is a, the highest point of the pressure surface is d, the vertex of the rear end is c, the line connecting the vertex a of the front end and the vertex c of the rear end is the blade chord, the length of the blade chord is L1, and the distance between the highest point d of the pressure surface and the vertex a of the front end is H2 in a direction perpendicular to the length of the blade chord. L1 and H2 satisfy the relationship: 1 / 10≤H2 / L1≤3 / 4.

[0017] This utility model discloses a multi-blade centrifugal fan, including the multi-blade centrifugal impeller and volute described above, wherein the multi-blade centrifugal impeller is installed inside the volute.

[0018] The beneficial effects of this multi-blade centrifugal impeller are as follows: Because a dune-shaped protrusion protruding towards the suction surface is provided near the front end of the blade, the structure of the dune-shaped protrusion has a good airflow guiding effect. Moreover, the position of the dune-shaped protrusion occupies the position where separation vortices are most likely to occur at the inlet. After the airflow flows in from the blade inlet, under the guiding effect of the dune-shaped protrusion, the uniformity and stability of the flow field can be improved. At the same time, it also improves the flow channel contraction coefficient of the impeller, thereby improving the problem of poor aerodynamic performance caused by the large airflow inlet impact loss and blade trailing edge separation loss in existing multi-blade centrifugal fans.

[0019] The beneficial effects of this multi-blade centrifugal fan are as follows: Due to the multi-blade centrifugal impeller mentioned above, after the airflow enters from the blade inlet, under the guidance of the dune-shaped protrusions, the uniformity and stability of the flow field can be improved. At the same time, the flow channel contraction coefficient of the impeller is also improved, thereby improving the problem of poor aerodynamic performance caused by the large airflow inlet impact loss and blade trailing edge separation loss in existing multi-blade centrifugal fans.

[0020] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the multi-blade centrifugal impeller structure according to an embodiment of the present invention;

[0022] Figure 2This is a partial structural schematic diagram of the multi-blade centrifugal impeller according to an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of the blades of the multi-blade centrifugal impeller according to an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the multi-blade centrifugal impeller from another direction according to an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of the structure of another type of blade of the multi-bladed centrifugal impeller according to an embodiment of the present invention.

[0026] Figure label:

[0027] 100. Impeller disk; 110. Shaft;

[0028] 200, blade; 210, front end; 220, rear end; 230, pressure surface; 240, suction surface; 250, dune-shaped protrusion; 260, blade chord;

[0029] 300. Impeller ring; 310. Reinforced structure. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0031] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0032] In the description of this embodiment, the terms "upper," "lower," "left," "right," "front," and "rear," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0033] This utility model discloses a multi-blade centrifugal impeller, referenced... Figure 1 , Figure 2 and Figure 4 As shown, the impeller includes an impeller disk 100, multiple blades 200, and an impeller ring 300. The impeller disk 100 and the impeller ring 300 are connected to the two ends of the multiple blades 200. Each blade 200 extends toward the center of the impeller disk 100. Each blade 200 has a front end 210 and a rear end 220 spaced radially along the impeller disk 100, and a pressure surface 230 and a suction surface 240 spaced circumferentially along the impeller disk 100. The front end 210 is positioned close to the center of the impeller disk 100. (Refer to...) Figure 3 As shown, the portion of blade 200 near the front end 210 has a dune-shaped protrusion 250 that bulges towards the suction surface 240. The dune-shaped protrusion 250 can cover part of the separation zone formed by the airflow at the front end 210. Understandably, simulation and experimental verification of the optimized model show that the blade structure in the prior art is very prone to forming separation vortices at the inlet, thereby reducing the aerodynamic performance of the entire impeller. In this embodiment, the multi-blade centrifugal impeller has a dune-shaped protrusion 250 protruding towards the suction surface 240 near the front end 210 of the blade 200. The dune-shaped protrusion 250 structure has a good airflow guiding effect, and the position of the dune-shaped protrusion 250 occupies the position where separation vortices are most likely to occur at the inlet. After the airflow flows in from the inlet of the blade 200, under the guiding effect of the dune-shaped protrusion 250, the uniformity and stability of the flow field can be improved. At the same time, it also improves the flow channel contraction coefficient of the impeller, thereby improving the problem of poor aerodynamic performance caused by the large airflow impact loss at the inlet and the separation loss at the trailing edge of the blade 200 in existing multi-blade centrifugal fans.

[0034] In addition, it should be noted that one end of the blade 200 is connected to the impeller disk 100, and the other end is fixed by the impeller ring 300. The fixed-end method can improve the installation stability of the blade 200, reduce the probability of the blade 200 deforming during operation, and thus extend the service life of the multi-blade centrifugal impeller.

[0035] Optional, see reference Figure 3 , Figure 5As shown, from the front end 210 to the rear end 220, the dune-shaped protrusion 250 includes a gradually widening section and a gradually narrowing section, with the larger end of the widening section facing the larger end of the narrowing section. It is understood that simulations and experimental verifications based on the optimization model show that the larger the width of the dune-shaped protrusion 250, the better the effect of reducing impact loss and separation loss. However, a larger dune-shaped protrusion 250 results in a relatively large size of the blade 200 near the front end, increasing the manufacturing difficulty of the blade 200 and making it prone to delamination during manufacturing, thus reducing the manufacturing yield of the blade 200. In this embodiment, the dune-shaped protrusion 250 is divided into two parts: a gradually widening section and a gradually narrowing section. This structure ensures the effectiveness of the dune-shaped protrusion 250 in reducing impact loss and separation loss, while also facilitating the manufacturing of the blade 200, avoiding delamination during manufacturing, and improving the manufacturing yield of the blade 200.

[0036] Optional, see reference Figure 3 , Figure 5 As shown, the front end 210 of the blade 200 forms a tapered structure with a gradually decreasing width. It can be understood that by forming a tapered structure at the front end 210 of the blade 200, the airflow enters the flow channel from the front end 210 of the blade 200. This tapered structure effectively guides the airflow and reduces airflow impact losses at the inlet. Optionally, the end of the tapered structure is an arc-shaped surface. Compared to a sharp-angled structure, an arc-shaped end face simplifies the manufacturing process, facilitates the manufacturing of the blade 200, and reduces the probability of blade 200 damage, thereby extending the service life of the blade 200. It should be further noted that in other embodiments of this invention, the shape of the front end 210 of the blade 200 can be selected from other shapes based on simulation and experimental verification of the optimization model, and is not limited to the tapered structure of this embodiment.

[0037] Optionally, the maximum width of the dune-shaped protrusion 250 is greater than the maximum width of the rear end 220, and the maximum width of the rear end 220 is greater than the maximum width of the front end 210. This further improves the uniformity and stability of the flow field, while also increasing the impeller's flow channel contraction coefficient, thereby addressing the problem of poor aerodynamic performance in existing multi-blade centrifugal fans caused by significant inlet impact losses and blade trailing edge separation losses.

[0038] Further optional, see reference Figure 1 and Figure 2As shown, a reinforcing structure 310 extending axially along the impeller disk 100 is provided on the outer peripheral wall of the impeller ring 300. It can be understood that the added reinforcing structure 310 can improve the strength of the entire multi-blade centrifugal impeller, further reduce the probability of blade deformation during operation, and thus extend the service life of the multi-blade centrifugal impeller.

[0039] Optionally, the blades 200, impeller ring 300, impeller disk 100, and reinforcing structure 310 are integrally molded parts. It is understood that having the blades 200, impeller ring 300, impeller disk 100, and reinforcing structure 310 integrally molded parts can, on the one hand, improve the overall strength of the multi-blade centrifugal impeller and further reduce the probability of blade 200 deformation during operation, thereby extending the service life of the multi-blade centrifugal impeller; on the other hand, it simplifies the manufacturing process of the multi-blade centrifugal impeller, which helps to reduce the manufacturing cost.

[0040] Optional, see reference Figure 1 As shown, a rotating shaft 110 extending circumferentially from the center of the impeller disk 100 is provided. It is understood that the added rotating shaft 110 facilitates the connection between the multi-bladed centrifugal impeller and the drive motor, thereby simplifying the use of the multi-bladed centrifugal impeller. Optionally, the rotating shaft 110 and the impeller disk 100 are integrally formed, which simplifies the manufacturing process of the multi-bladed centrifugal impeller and helps reduce its manufacturing cost.

[0041] refer to Figure 3 As shown, the vertex of the front end 210 is a, the highest point of the dune-shaped protrusion 250 is b, the vertex of the rear end 220 is c, and the highest point of the pressure surface 230 is d. The parameter range of the blade 200 in this embodiment is as follows:

[0042] Along the length of the blade chord 260, the distance between the highest point b of the dune-shaped protrusion 250 and the vertex a of the front end 210 is L2. L1 and L2 satisfy the relationship: 1 / 8 ≤ L2 / L1 ≤ 1 / 2. Specifically, the ratio of L2 / L1 can be 1 / 8, 1 / 7, 1 / 6, 1 / 5, 1 / 4, 1 / 3, 1 / 2, or other values ​​within the range of 1 / 8 to 1 / 2.

[0043] In the direction perpendicular to the length of the blade chord 260, the distance between the highest point b of the dune-shaped protrusion 250 and the vertex a of the front end 210 is H1. L1 and H1 satisfy the relationship: 1 / 6 ≤ H1 / L1 ≤ 3 / 4. Specifically, the ratio of H1 / L1 can be 1 / 6, 1 / 5, 1 / 4, 1 / 3, 1 / 2, 3 / 4, or other values ​​between 1 / 6 and 3 / 4.

[0044] Along the length of the blade chord 260, the distance between the highest point d of the pressure surface 230 and the vertex a of the front end 210 is L3. L1 and L3 satisfy the relationship: 1 / 5 ≤ L3 / L1 ≤ 1 / 2. Specifically, the ratio of L6 / L1 can be 1 / 5, 1 / 4, 1 / 3, 1 / 2, or other values ​​within the range of 1 / 5 to 1 / 2.

[0045] In the direction perpendicular to the length of the blade chord 260, the distance between the highest point d of the pressure surface 230 and the vertex a of the front end 210 is H2. L1 and H2 satisfy the relationship: 1 / 10 ≤ H2 / L1 ≤ 3 / 4. Specifically, the ratio of H5 / L1 can be 1 / 10, 1 / 9, 1 / 8, 1 / 7, 1 / 6, 1 / 5, 1 / 4, 1 / 3, 1 / 2, 3 / 4, or other values ​​between 1 / 10 and 3 / 4.

[0046] Simulation and experimental verification based on the optimization model show that the multi-blade centrifugal impeller in this embodiment has the following advantages:

[0047] First, compared with existing technologies, the separation area of ​​the suction surface 240 of blade 200 is significantly reduced;

[0048] Second, the gas flow channel contraction coefficient increases, and the flow field uniformity of the multi-bladed centrifugal impeller is greatly improved.

[0049] Third, static pressure efficiency is significantly improved, static pressure increases significantly under rated operating conditions and the flow-pressure curve is widened;

[0050] Fourth: Under the same air volume conditions, the speed of the multi-blade centrifugal impeller is greatly reduced, which can significantly reduce the operating noise of the multi-blade centrifugal fan.

[0051] This utility model discloses a multi-blade centrifugal fan, including the aforementioned multi-blade centrifugal impeller and volute, with the multi-blade centrifugal impeller installed inside the volute. Because this embodiment of the multi-blade centrifugal fan has the aforementioned multi-blade centrifugal impeller, the airflow entering from the inlet of blade 200, guided by the dune-shaped protrusion 250, can improve the uniformity and stability of the flow field. It also increases the impeller's flow channel contraction coefficient, thereby improving the problem of poor aerodynamic performance in existing multi-blade centrifugal fans when the airflow experiences significant inlet impact loss and blade trailing edge separation loss.

[0052] It should be noted that the structure of the volute of the multi-blade centrifugal fan can be selected according to actual needs. The connection method between the multi-blade centrifugal impeller and the volute is existing technology, and no specific limitation is made here on the connection method between the multi-blade centrifugal impeller and the volute.

[0053] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0054] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A multi-blade centrifugal impeller, characterized in that, The impeller includes an impeller disk (100), a plurality of blades (200), and an impeller ring (300). The impeller disk (100) and the impeller ring (300) are connected to both ends of the plurality of blades (200). Each blade (200) extends toward the center of the impeller disk (100), and each blade (200) has a front end (210) and a rear end (220) that are radially spaced along the impeller disk (100). The impeller disk (100) has pressure surfaces (230) and suction surfaces (240) spaced circumferentially along its front end (210) near the center of the impeller disk (100). The blade (200) near the front end (210) has dune-shaped protrusions (250) protruding toward the suction surface (240). The dune-shaped protrusions (250) are used to reduce the eddies formed by the airflow at the front end (210).

2. The multi-blade centrifugal impeller according to claim 1, characterized in that, From the front end (210) toward the rear end (220), the dune-shaped protrusion (250) includes a gradually widening section and a gradually narrowing section, with the larger end of the gradually widening section facing the larger end of the gradually narrowing section.

3. The multi-blade centrifugal impeller according to claim 1, characterized in that, The front end (210) of the blade (200) is formed with a tapered structure whose width gradually decreases.

4. The multi-blade centrifugal impeller according to claim 1, characterized in that, The maximum width of the dune-shaped protrusion (250) is greater than the maximum width of the rear end (220), and the maximum width of the rear end (220) is greater than the maximum width of the front end (210).

5. The multi-blade centrifugal impeller according to claim 1, characterized in that, The outer peripheral wall of the impeller ring (300) is provided with a reinforcing structure (310) extending axially along the impeller disk (100).

6. The multi-blade centrifugal impeller according to claim 1, characterized in that, The vertex of the front end (210) is a, the highest point of the dune-shaped protrusion (250) is b, the vertex of the rear end (220) is c, the line connecting the vertex a of the front end (210) and the vertex c of the rear end (220) is the blade chord (260) of the blade (200), the length of the blade chord (260) is L1, and the distance between the highest point b of the dune-shaped protrusion (250) and the vertex a of the front end (210) along the length direction of the blade chord (260) is L2. L1 and L2 satisfy the relationship: 1 / 8≤L2 / L1≤1 / 2.

7. The multi-blade centrifugal impeller according to claim 1, characterized in that, The vertex of the front end (210) is a, the highest point of the dune-shaped protrusion (250) is b, the vertex of the rear end (220) is c, the line connecting the vertex a of the front end (210) and the vertex c of the rear end (220) is the blade chord (260) of the blade (200), the length of the blade chord (260) is L1, and the distance between the highest point b of the dune-shaped protrusion (250) and the vertex a of the front end (210) is H1 in a direction perpendicular to the length of the blade chord (260). L1 and H1 satisfy the relationship: 1 / 6≤H1 / L1≤3 / 4.

8. The multi-blade centrifugal impeller according to claim 1, characterized in that, The vertex of the front end (210) is a, the highest point of the pressure surface (230) is d, the vertex of the rear end (220) is c, the line connecting the vertex a of the front end (210) and the vertex c of the rear end (220) is the blade chord (260) of the blade (200), the length of the blade chord (260) is L1, and the distance between the highest point d of the pressure surface (230) and the vertex a of the front end (210) along the length direction of the blade chord (260) is L3. L1 and L3 satisfy the relationship: 1 / 5≤L3 / L1≤1 / 2.

9. The multi-blade centrifugal impeller according to claim 1, characterized in that, The vertex of the front end (210) is a, the highest point of the pressure surface (230) is d, the vertex of the rear end (220) is c, the line connecting the vertex a of the front end (210) and the vertex c of the rear end (220) is the blade chord (260) of the blade (200), the length of the blade chord (260) is L1, and the distance between the highest point d of the pressure surface (230) and the vertex a of the front end (210) is H2, along the direction perpendicular to the length of the blade chord (260). L1 and H2 satisfy the relationship: 1 / 10≤H2 / L1≤3 / 4.

10. A multi-blade centrifugal fan, characterized in that, Includes the multi-bladed centrifugal impeller and volute as described in any one of claims 1-9, wherein the multi-bladed centrifugal impeller is installed inside the volute.

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