Efficient centrifugal wind wheel with C-shaped outlet

Abstract

The utility model relates to the field of centrifugal wind wheels, and discloses an efficient centrifugal wind wheel with a C-shaped outlet. The molded surface of the blade is a three-dimensional curved surface, the edge contour line of the inner side of the blade is the front edge of the blade, the outer side of the blade is the tail edge of the blade, and the contour of the tail edge of the blade is C-shaped. The connecting point of the blade tail edge and the lower disc is a point A, the connecting point of the blade tail edge and the upper disc is a point B, the tangent line of the lower end root of the blade tail edge is a line A, the tangent line of the upper end root of the blade tail edge is a line B, the included angle between the line A and the first axis passing through the lower end point of the blade tail edge is beta 2, and the included angle between the line B and the second axis passing through the upper end point of the blade tail edge is beta 1. The first axis and the second axis are both parallel to the center line of the centrifugal wind wheel, and beta1 is larger than beta2. The centrifugal wind wheel has the advantages of high efficiency and low wind noise.

Description

Technical Field

[0001] The utility model relates to the technical field of fan wheels, in particular to an efficient centrifugal fan wheel with a C-shaped outlet. Background Art

[0002] At present, the trailing edges of the blades of backward centrifugal fan wheels mostly adopt an equal-diameter design. This design easily causes the air flow in the fan wheel to concentrate on the side of the hub in the air passage, resulting in too high local wind speed, exacerbating the unevenness of the air flow out of the fan wheel, and further inducing noise problems; there are also some backward centrifugal fan wheels with a variable trailing-edge diameter design, but most of their designs are based on two-dimensional blade expansion, and their aerodynamic performance and low-noise characteristics are not excellent enough. Chinese Patent Application No. 202110806245.3 discloses a backward centrifugal fan wheel, a centrifugal fan and an air conditioner. By adopting a variable-diameter design for the blade trailing edge, with a larger diameter at the blade tip side and a smaller diameter at the blade root side, and modulating and balancing the work input of the blade profiles at different blade heights, the unevenness and mixing degree of the air flow at the outlet of the fan wheel can be appropriately reduced, which helps to suppress noise. The blade design of this structure is relatively complex, and it cannot eliminate the air flow wake and vortices. Summary of the Utility Model

[0003] Aiming at the deficiencies in the prior art, the utility model provides an efficient centrifugal fan wheel with a C-shaped outlet.

[0004] To solve the above technical problems, the utility model is solved by the following technical solutions:

[0005] An efficient centrifugal fan wheel with a C-shaped outlet, comprising an upper disk and a lower disk arranged in parallel. The upper disk and the lower disk are connected by a plurality of blades, and air ducts are formed between adjacent blades; the profile of the blade is a three-dimensional curved surface. The edge contour line of the blade on the inner side is the blade leading edge, and the outer side is the blade trailing edge. The contour of the blade trailing edge is C-shaped; the point where the blade trailing edge is connected to the lower disk is point A, and the point where it is connected to the upper disk is point B. The tangent line at the root of the lower end of the blade trailing edge is line A, and the tangent line at the root of the upper end of the blade trailing edge is line B. The included angle between line A and axis 1 passing through the lower end point of the blade trailing edge is β2, and the included angle between line B and axis 2 passing through the upper end point of the blade trailing edge is β1. Both axis 1 and axis 2 are parallel to the center line of the centrifugal fan wheel, and β1 is greater than β2.

[0006] Preferably, the point where the blade leading edge is connected to the lower disk is point C, and the point where it is connected to the upper disk is point D. The tangent line at the root of the lower end of the blade leading edge is line C, and the tangent line at the root of the upper end of the blade leading edge is line D. The included angle between line C and axis 3 passing through the lower end point of the blade leading edge is δ2, and the included angle between line D and axis 4 passing through the upper end point of the blade leading edge is δ1. Both axis 3 and axis 4 are parallel to the center line of the centrifugal fan wheel, and δ1 is greater than δ2.

[0007] Preferably, the upper part is the air inlet, and the diameter of the air inlet gradually increases in the air flow direction.

[0008] Preferably, the diameter of the lower disk of the impeller increases from the air inlet towards the outlet in the axial section.

[0009] Preferably, the included angle α1 between the tangent of the generatrix of the upper disk of the impeller and the perpendicular line of the axis gradually decreases from the air inlet towards the outlet. This design of the curve angle is beneficial to achieving high efficiency and low noise of the wind wheel.

[0010] Preferably, the included angle α2 between the tangent of the generatrix of the lower disk of the impeller and the perpendicular line of the axis gradually decreases from the air inlet towards the outlet. This design of the curve angle is beneficial to achieving high efficiency and low noise of the wind wheel.

[0011] Preferably, the blade is a sheet-like part with equal thickness, and the blade is a metal blade or a plastic blade.

[0012] Preferably, the upper disk and the lower disk are of an integral structure, and the blade is fixed to the upper and lower disks by welding or riveting.

[0013] Preferably, the outer side surface of the upper disk is a frustum-shaped outer ring surface that is smaller at the upper part and larger at the lower part.

[0014] Preferably, chamfers are provided at both the leading edge and the trailing edge of the blade. The chamfer at the leading edge of the blade can inhibit the separation of the oncoming airflow at the leading edge of the blade, thereby improving the efficiency of the impeller, and the chamfer at the trailing edge can eliminate the airflow wake and vortices, reducing the noise of the impeller.

[0015] This solution has the following advantages compared with the prior art. By designing the angle, the wind noise of the airflow can be reduced, the noise can be reduced by 2 dB, and the efficiency can be improved, especially more significantly when the flow rate is large. At the same time, the eddy current between the upper and lower disks can be reduced, thereby improving the efficiency of the impeller. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the wind wheel.

[0017] Figure 2 It is a sectional view of the wind wheel.

[0018] Figure 3 It is a sectional view of the wind wheel.

[0019] Figure 4 It is a noise comparison diagram.

[0020] Figure 5 It is an efficiency comparison diagram.

[0021] Figure 6 It is a flow field diagram of the traditional blade.

[0022] Figure 7 It is a flow field diagram of this solution.

[0023] The technical names of the reference numerals in the figure are: 1 - upper disc, 2 - lower disc, 3 - blade, 31 - leading edge of the blade, 32 - trailing edge of the blade, 4 - line A, 5 - line B, 6 - line C, 7 - line D, 11 - bus bar of the upper disc, 12 - bus bar of the lower disc. Detailed implementation mode

[0024] The present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0025] Embodiment 1

[0026] An efficient centrifugal wind wheel with a C-shaped outlet includes a parallel upper disc 1 and a lower disc 2. The upper disc 1 and the lower disc 2 are connected by a plurality of blades 3, and air ducts are formed between adjacent blades 3. The profile of the blade 3 is a three-dimensional curved surface. The edge contour line of the blade 3 on the inner side is the leading edge 31 of the blade, and the outer side is the trailing edge 32 of the blade. The contour of the trailing edge 32 of the blade is C-shaped. The point where the trailing edge 32 of the blade is connected to the lower disc 2 is point A, and the point where it is connected to the upper disc 1 is point B. The tangent line at the lower root of the trailing edge 32 of the blade is line A 4, and the tangent line at the upper root of the trailing edge 32 of the blade is line B 5. The included angle between line A 4 and axis 1 passing through the lower end point of the trailing edge 32 of the blade is β2, and the included angle between line B 5 and axis 2 passing through the upper end point of the trailing edge 32 of the blade is β1. Both axis 1 and axis 2 are parallel to the center line of the centrifugal wind wheel, and β1 is greater than β2. Among them, both axis 1 and axis 2 are auxiliary lines used to express the angle positions. Since the tangent included angle at the upper end is greater than the tangent included angle at the lower end, through experimental verification, this structure can significantly reduce the airflow noise. At the same time, in cooperation with the design of the α angle at the upper end, the eddy current at the tail is reduced, and the efficiency of the wind wheel is improved. Among them, the air flow enters the wind wheel from the inlet in the middle of the upper disc 1, and then passes through the guiding of the blade 3 and flows out from the air ducts between the blades 3 to the outside.

[0027] For the convenience of description, it is defined that the point where the leading edge 31 of the blade is connected to the lower disc 2 is point C, and the point where it is connected to the upper disc 1 is point D. The tangent line at the lower root of the leading edge 31 of the blade is line C 6, and the tangent line at the upper root of the leading edge 31 of the blade is line D 7. The included angle between line C 6 and axis 3 passing through the lower end point of the leading edge 31 of the blade is δ2, and the included angle between line D 7 and axis 4 passing through the upper end point of the leading edge 31 of the blade is δ1. Both axis 3 and axis 4 are parallel to the center line of the centrifugal wind wheel, and δ1 is greater than δ2.

[0028] In this embodiment, the angles of β1 and β2 range from 20° to 50°, and the angles of δ1 and δ2 are from 0° to 60°.

[0029] In this embodiment, the upper piece is the air inlet, and the diameter of the air inlet gradually increases in the air flow direction. The diameter of the lower disc 2 of the impeller increases from the air inlet towards the outlet in the axial section.

[0030] The included angle α1 between the tangent of the bus bar 11 on the upper disk of the impeller and the vertical line of the axis gradually decreases from the air inlet towards the outlet. This design of the curve angle is beneficial to achieving high efficiency and low noise of the wind wheel. The included angle α2 between the tangent of the bus bar 12 on the lower disk of the impeller and the vertical line of the axis gradually decreases from the air inlet towards the outlet. The bus bar represents the contour line of the edge of the section. This design of the curve angle is beneficial to achieving high efficiency and low noise of the wind wheel. This design of the curve angle is beneficial to the forming of the upper and lower disks 2, and can reduce the eddy current of the upper and lower disks 2, thereby improving the impeller efficiency.

[0031] For the convenience of forming and the design of the space air duct, the blade 3 is a sheet-like part with equal thickness. The blade 3 is a metal blade 3 or a plastic blade 3. In this embodiment, the metal blade 3 is selected. In order to minimize noise and make the air flow smoother, the upper disk 1 and the lower disk 2 are of an integral structure. The blade 3 is fixedly connected to the upper disk 1 and the lower disk 2 by welding or riveting. In this embodiment, welding fixation is selected.

[0032] Chamfers are provided at the edges of the leading edge 31 and the trailing edge 32 of the blade. The chamfer at the leading edge 31 of the blade can inhibit the separation of the oncoming air flow at the leading edge 31, thereby improving the impeller efficiency. The chamfer at the trailing edge can eliminate the air flow wake and vortices, reducing the impeller noise.

[0033] This solution has the following advantages compared with the prior art. Through the angle design, the wind noise of the air flow can be reduced, the noise can be reduced by 2 dB, and the efficiency can be improved. Especially when the flow rate is large, the efficiency improvement is more significant. At the same time, the eddy current of the upper and lower disks 2 can be reduced, thereby improving the efficiency of the impeller.

[0034] Embodiment 2

[0035] The difference between this embodiment and Embodiment 1 is that: the blade 3 is fixedly connected to the upper disk 1 and the lower disk 2 by riveting.

[0036] Embodiment 3

[0037] The difference between this embodiment and Embodiment 1 is that: the outer side surface of the upper disk 1 is a frustum-shaped outer ring surface with a smaller upper part and a larger lower part.

Claims

1. A high-efficiency centrifugal impeller with a C-shaped outlet, comprising an upper plate and a lower plate arranged in parallel, the upper plate and the lower plate being connected by a plurality of blades, characterized in that: An air duct is formed between adjacent blades; the profile of the blade is a three-dimensional curved surface, the inner edge contour line of the blade is the leading edge of the blade, the outer side is the trailing edge of the blade, and the contour of the trailing edge of the blade is C-shaped; the point where the trailing edge of the blade connects with the lower plate is point A, and the point where it connects with the upper plate is point B, the root tangent of the lower end of the trailing edge of the blade is line A, the root tangent of the upper end of the trailing edge of the blade is line B, the angle between line A and the axis one passing through the lower end point of the trailing edge of the blade is β2, the angle between line B and the axis two passing through the upper end point of the trailing edge of the blade is β1, both axis one and axis two are parallel to the center line of the centrifugal wind wheel, and β1 is greater than β2.

2. The high-efficiency centrifugal impeller with a C-shaped outlet according to claim 1, characterized in that: The point where the leading edge of the blade connects with the lower plate is point C, and the point where it connects with the upper plate is point D. The tangent line at the root of the lower end of the leading edge of the blade is line C, and the tangent line at the root of the upper end of the leading edge of the blade is line D. The angle between line C and axis three passing through the lower end of the leading edge of the blade is δ2, and the angle between line D and axis four passing through the upper end of the leading edge of the blade is δ1. Axis three and axis four are both parallel to the center line of the centrifugal wind wheel, and δ1 is greater than δ2.

3. The high-efficiency centrifugal impeller with a C-shaped outlet according to claim 1, characterized in that: The upper piece is an air inlet, and the diameter of the air inlet gradually increases in the direction of air flow.

4. The high-efficiency centrifugal impeller with a C-shaped outlet according to claim 3, characterized in that: The diameter of the impeller lower plate in the axial section increases from the air inlet toward the outlet.

5. The high-efficiency centrifugal impeller with a C-shaped outlet according to claim 3, characterized in that: The angle α1 between the tangent line of the impeller upper disk generatrix and the perpendicular line of the axis gradually decreases from the air inlet to the outlet.

6. The high-efficiency centrifugal impeller with a C-shaped outlet according to claim 1, characterized in that: The angle α2 between the tangent line of the impeller lower disc generatrix and the perpendicular line of the axis gradually decreases from the air inlet to the outlet.

7. The high-efficiency centrifugal impeller with a C-shaped outlet according to claim 1, characterized in that: The blades are sheet-like pieces with equal thickness, and are metal blades or plastic blades; the upper plate and the lower plate are an integrated structure, and the blades and the upper plate and the lower plate are fixed by welding or riveting.

8. The high-efficiency centrifugal impeller with a C-shaped outlet according to claim 1, characterized in that: The angle range of β1 and β2 is 20° to 50°, and the outer side surface of the upper plate is a truncated cone-shaped outer ring surface with a small upper portion and a large lower portion.

9. The high-efficiency centrifugal impeller with a C-shaped outlet according to claim 2, characterized in that: The angles of δ1 and δ2 are 0° to 60°.

10. The high-efficiency centrifugal impeller with a C-shaped outlet according to claim 1, characterized in that: The leading edge of the blade and the trailing edge of the blade are both provided with chamfers.

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