Centrifugal fan and range hood comprising same
By optimizing the volute shape and the position of the oil leakage holes, the problems of aerodynamic performance loss and noise increase caused by the oil leakage holes of the centrifugal fan were solved, and the fan performance was improved and the noise was reduced.
Patent Information
- Application Number
- CN202421503052.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-27
- Publication Date
- 2025-03-18
- Estimated Expiration
- 2034-06-27
AI Technical Summary
The oil leakage holes of existing centrifugal fans will generate high-pressure gas jets during operation, resulting in a loss of aerodynamic performance and increased noise.
By changing the shape of the volute and the position of the oil leakage hole, the oil leakage hole can avoid the direct impact of the high-pressure gas. The outward expansion area and inclined surface design are adopted to reduce the airflow impact and optimize the flow channel structure.
Effectively improve fan performance, reduce airflow impact at the oil leakage hole, and reduce fan operation noise.
Smart Images
Figure CN222633505U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of range hoods. Background Art
[0002] Existing range hoods generally suck out oil smoke through fans. There are various types of fans. Centrifugal fans, such as multi-blade centrifugal fans, are widely used in various household appliances such as air conditioners, range hoods, air purifiers, and ventilation fans due to their compact structure, high pressure coefficient, large flow coefficient, and low noise.
[0003] When a centrifugal fan is used in a range hood, an oil leakage hole needs to be opened on the fan volute to discharge the grease (liquid) separated from the smoke during the exhaust process. However, during the operation of the centrifugal fan, the opening of the existing oil leakage hole on the volute will bring adverse effects. The high-pressure gas generated by the impeller of the centrifugal fan will be ejected outward from the oil leakage hole, which will lose the aerodynamic performance of the fan and increase the fan noise, but the oil leakage hole is indispensable. Utility Model Content
[0004] The technical problem to be solved by the utility model is to overcome the defects in the prior art that the oil leakage hole of the centrifugal fan will generate high-pressure gas to spray outward, which will lose the aerodynamic performance and make high noise, and provide a centrifugal fan and a range hood including the same.
[0005] The utility model solves the above technical problems through the following technical solutions:
[0006] A centrifugal fan comprises a volute and an impeller, wherein the volute comprises an annular wall arranged along the circumference of the impeller and an end cover arranged along the axial direction of the impeller, a portion of the annular wall extends at least along the axial direction of the impeller and forms an extended area that exceeds the end face of the impeller in the axial direction of the impeller, an oil leakage hole is arranged on the extended area, and the oil leakage hole connects the inside and the outside of the volute.
[0007] In this solution, by changing the shape of the volute and the position of the oil leakage hole, the oil leakage hole can avoid the direct impact of the high-pressure gas during the operation of the centrifugal fan, which is conducive to reducing noise. The change of the shape of the volute is easy to achieve, and the space inside the volute will not be occupied, thereby ensuring the performance of the fan.
[0008] Preferably, the area of the end cover connected to the extension area is an outward expansion area, wherein, in the process of extending from the side of the outward expansion area close to the impeller to the side of the outward expansion area away from the impeller, the distance of the outward expansion area relative to the end face of the impeller in the axial direction increases. The outward expansion area causes a corresponding change in the shape of the local flow channel inside the volute, and the outward expansion area increases the flow area of the local flow channel, which is conducive to improving the performance of the fan.
[0009] Preferably, the outward expansion area is an inclined surface, and the outward expansion area and the end surface of the impeller form an outward expansion angle. The outward expansion area in the form of an inclined surface is simple to process, and through the gradual outward expansion of the inclined surface, the smooth flow of the internal airflow can be ensured, and the generation of noise can be reduced.
[0010] Preferably, the angle of the expansion angle is 5-15 degrees. The expansion angle should not be too large to avoid causing flow separation, inducing stagnation vortex, and hindering the continuity of flow in the flow channel in the volute, nor should it be too small to avoid insufficient weakening of the impact of high-speed airflow at the oil leakage hole. The expansion angle of 5-15 degrees can balance the internal airflow performance and the impact on the oil leakage hole.
[0011] Preferably, the side of the outward expansion area close to the impeller does not exceed the area corresponding to the diameter of the impeller, thereby avoiding an increase in the leakage gap in the front disk area of the impeller.
[0012] Preferably, the radial distance from the outer diameter of the impeller to the annular wall at the position corresponding to the extension area is the first distance, and the radial distance from the side of the expansion area close to the impeller to the annular wall at the position corresponding to the extension area is the second distance, and the second distance is 0.5-0.96 times the first distance. When expanding outward, in order to avoid the formation of stagnant flow in the expansion area, which causes increased noise and poor connection between the local flow channel and the front and rear flow channels, the second distance should be as large as possible. Of course, the second distance should not exceed the area corresponding to the impeller diameter to avoid increasing the leakage gap in the impeller front disk area.
[0013] Preferably, the intersection boundary between the other areas of the end cap and the outward expansion area is a straight line, the annular wall where the extension area is located is a plane wall, and the intersection boundary is parallel to the plane wall. The straight intersection boundary and the parallel plane wall are easy to process.
[0014] Preferably, the centrifugal fan includes an air inlet ring, the air inlet ring is located at the periphery of the air inlet of the volute, and the air inlet ring is connected to the volute, wherein the inner ring side of the air inlet ring is formed with an upwardly raised guide surface, the outer ring side is formed with an outer ring surface that fits the volute, and the portion of the outer ring surface close to the outward expansion area fits with the intersection boundary. The guide surface can smoothly guide the wind into the air inlet ring, and by fitting with the intersection boundary, the distance between the outward expansion area and the air inlet can be made closer.
[0015] Preferably, the volute comprises an air outlet, and the oil leakage hole and the extension area are arranged on an annular wall on a side opposite to the air outlet.
[0016] A range hood comprises the centrifugal fan.
[0017] The positive progressive effect of the utility model is that the utility model can effectively improve the performance of the fan, reduce the impact of the airflow at the oil leakage hole, and thus reduce the running noise of the fan. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 The figure is a schematic diagram of the three-dimensional structure of a centrifugal fan according to a preferred embodiment of the utility model.
[0019] Figure 2 This is a front view structural schematic diagram of a centrifugal fan according to a preferred embodiment of the utility model.
[0020] Figure 3 The figure is a schematic side view of the centrifugal fan according to a preferred embodiment of the utility model.
[0021] Figure 4 The figure is a bottom view structural diagram of a centrifugal fan according to a preferred embodiment of the utility model.
[0022] Figure 5 for Figure 4 AA direction cross-sectional view.
[0023] Figure 6 It is a partial enlarged schematic diagram of the interior of the volute of a preferred embodiment of the utility model. DETAILED DESCRIPTION
[0024] The present invention is further described below by way of embodiments, but the present invention is not limited to the scope of the embodiments.
[0025] like Figure 1-Figure 6 As shown, this preferred embodiment discloses a centrifugal fan, such as Figure 1-Figure 3 As shown, this embodiment includes a volute 100 and an impeller 200. The volute 100 includes an annular wall 110 arranged along the circumference of the impeller 200 and an end cover 120 arranged along the axial direction x of the impeller 200. A portion of the annular wall 110 extends at least along the axial direction x of the impeller 200, and forms an extended area 111 that exceeds the end surface of the impeller 200 in the axial direction x of the impeller 200. An oil leakage hole 130 is arranged on the extended area 111, and the oil leakage hole 130 connects the inside and the outside of the volute 100.
[0026] In this embodiment, by changing the shape of the volute 100 and the position of the oil leakage hole 130, the oil leakage hole 130 can avoid the direct impact of the high-pressure gas during the operation of the centrifugal fan, which is conducive to reducing noise. The shape change of the volute 100 is easy to achieve, and the space inside the volute 100 will not be occupied, thereby ensuring the performance of the fan.
[0027] like Figure 1-Figure 3As shown, in this embodiment, the area of the end cover 120 connected to the extension area 111 is preferably the expansion area 121, wherein, in the process of extending from the side of the expansion area 121 close to the impeller 200 to the side of the expansion area 121 away from the impeller 200, the distance of the expansion area 121 relative to the end face of the impeller 200 in the axial direction x increases. The expansion area 121 causes a corresponding change in the shape of the local flow channel inside the volute 100, and the expansion area 121 increases the flow area of the local flow channel, which is conducive to improving the performance of the fan.
[0028] like Figure 6 As shown, in this embodiment, the outward expansion area 121 is preferably an inclined surface, and the outward expansion area 121 forms an outward expansion angle d with the end surface of the impeller 200. The outward expansion area 121 in the form of an inclined surface is simple to process, and the gradual outward expansion of the inclined surface can ensure the smooth flow of the internal airflow and reduce the generation of noise.
[0029] like Figure 6 As shown, in this embodiment, the preferred angle of the expansion angle d is 5-15 degrees. The expansion angle d should not be too large to avoid causing flow separation, inducing stagnation vortex, and hindering the continuity of the flow in the flow channel in the volute 100, nor should it be too small to avoid insufficient weakening of the impact of the high-speed airflow at the position of the oil leakage hole 130. The expansion angle d of 5-15 degrees can balance the internal airflow performance and the impact on the oil leakage hole 130.
[0030] like Figure 6 As shown, in this embodiment, the side of the outward expansion area 121 close to the impeller 200 preferably does not exceed the area corresponding to the diameter of the impeller 200. This can avoid the increase of the leakage gap in the front disk area of the impeller 200.
[0031] like Figure 6 As shown, in a further preferred embodiment of the present invention, the radial distance from the outer diameter of the impeller 200 to the annular wall 110 at the position corresponding to the extension area 111 is the first distance b, and the radial distance from the side of the expansion area 121 close to the impeller 200 to the annular wall 110 at the position corresponding to the extension area 111 is the second distance c, and the second distance c is 0.5-0.96 times the first distance b. When expanding outward, in order to avoid the formation of stagnant flow in the expansion area 121, which causes increased noise and poor connection between the local flow channel and the front and rear flow channels, the second distance c should be as large as possible. Of course, the second distance c should not exceed the area corresponding to the diameter of the impeller 200 to avoid increasing the leakage gap in the front disk area of the impeller 200. In a more specific embodiment, the first distance b=101.1 mm, the second distance c=96.12 mm, and the outward expansion angle d=13.36°. Compared with conventional centrifugal fans, with the same air volume, the centrifugal fan of the utility model can reduce noise by 0.7 dB under maximum air volume conditions and by 0.5 dB under working air volume conditions.
[0032] like Figure 2 As shown, in this embodiment, the intersection boundary 122 between the other areas of the end cap 120 and the expanded area 121 is preferably a straight line, the annular wall 110 where the extended area 111 is located is a plane wall, and the intersection boundary 122 is parallel to the plane wall. The straight intersection boundary 122 and the parallel plane wall are easy to process.
[0033] like Figure 2 As shown, in this embodiment, the centrifugal fan includes an air inlet ring 300, which is located at the periphery of the air inlet 140 of the volute 100, and the air inlet ring 300 is connected to the volute 100, wherein the inner ring side of the air inlet ring 300 is formed with an upwardly raised guide surface 310, and the outer ring side is formed with an outer ring surface that fits the volute 100, and the portion of the outer ring surface close to the outward expansion area 121 fits with the intersection boundary 122. The guide surface 310 can smoothly guide the wind into the air inlet ring 300, and by fitting with the intersection boundary 122, the distance between the outward expansion area 121 and the air inlet 140 can be made closer.
[0034] like Figure 2 As shown, in this embodiment, the volute 100 includes an air outlet 150 , and the oil leakage hole 130 and the extension area 111 are arranged on the annular wall 110 on a side opposite to the air outlet 150 .
[0035] The centrifugal fan of this embodiment can be applied to various range hoods using centrifugal fans. The utility model can effectively improve the fan performance, reduce the airflow impact at the oil leakage hole 130, and thus reduce the fan operation noise.
[0036] Although the specific implementations of the utility model are described above, those skilled in the art should understand that this is only an example, and the protection scope of the utility model is defined by the attached claims. Those skilled in the art can make various changes or modifications to these implementations without departing from the principle and essence of the utility model, but these changes and modifications fall within the protection scope of the utility model.
Claims
1. A centrifugal fan, comprising a volute and an impeller, wherein the volute comprises an annular wall arranged along the circumference of the impeller and an end cover arranged along the axial direction of the impeller, characterized in that: A portion of the annular wall extends at least along the axial direction of the impeller and forms an extended area beyond the end surface of the impeller in the axial direction of the impeller. An oil leakage hole is provided in the extended area, and the oil leakage hole connects the inside and the outside of the volute.
2. The centrifugal fan according to claim 1, characterized in that: The area of the end cover connected to the extension area is an outward expansion area, wherein during the extension process from the side of the outward expansion area close to the impeller to the side of the outward expansion area away from the impeller, the distance of the outward expansion area relative to the end face of the impeller in the axial direction increases.
3. The centrifugal fan according to claim 2, characterized in that: The outward expansion area is an inclined surface, and the outward expansion area and the end surface of the impeller form an outward expansion angle.
4. The centrifugal fan according to claim 3, characterized in that: The angle of the outward expansion angle is 5-15 degrees.
5. The centrifugal fan according to claim 2, characterized in that: The side of the outward expansion area close to the impeller does not exceed the area corresponding to the diameter of the impeller.
6. The centrifugal fan according to claim 5, characterized in that: The radial distance from the outer diameter of the impeller to the annular wall at the position corresponding to the extended area is a first distance, and the radial distance from the side of the expanded area close to the impeller to the annular wall at the position corresponding to the extended area is a second distance, and the second distance is 0.5-0.96 times the first distance.
7. The centrifugal fan according to claim 2, characterized in that: The intersection boundary between the other areas of the end cover and the outward expansion area is a straight line, the annular wall where the extension area is located is a plane wall, and the intersection boundary is parallel to the plane wall.
8. The centrifugal fan according to claim 7, characterized in that: The centrifugal fan includes an air inlet ring, which is located at the periphery of the air inlet of the volute and is connected to the volute, wherein an inner ring side of the air inlet ring is formed with an upwardly raised guide surface, and an outer ring side is formed with an outer ring surface that fits the volute, and a portion of the outer ring surface close to the outward expansion area is in contact with the intersection boundary.
9. The centrifugal fan according to any one of claims 1 to 8, characterized in that: The volute comprises an air outlet, and the oil leakage hole and the extension area are arranged on an annular wall on a side opposite to the air outlet.
10. A range hood, characterized in that: The range hood comprises the centrifugal fan as claimed in any one of claims 1 to 9.