Fan blade, fan and range hood

Abstract

The utility model provides a fan blade, fan and range hood, the fan blade comprises a blade body and a shunt structure, the blade body has a suction surface and a pressure surface, the shunt structure is arranged on the peripheral side of the suction surface, and the shunt structure is arranged on the edge of one side of the blade body close to an impeller middle disc. In the section direction, the arc length of the flow dividing structure is 1 / 6-1 / 4 of the arc length of the blade body, the flow dividing structure and the blade body are coaxially arranged, the gap between the flow dividing structure and the blade body is delta, and the value range of delta is 1 / 10-1 / 5 of the gap between every two adjacent blade bodies in the fan. By arranging the shunting structure and limiting the size of the shunting structure and the gap between the shunting structure and the blade body, the working efficiency of the fan blade is improved, the performance loss of a fan is reduced, and the noise of the fan is reduced.

Description

Technical Field

[0001] The utility model particularly relates to a fan blade, a fan and a range hood. Background Art

[0002] The multi-wing centrifugal fan is the core component of the range hood fan system, which is characterized by large flow rate, high pressure coefficient and relatively low noise. Therefore, the multi-wing centrifugal fan is widely used in electrical appliances such as air conditioners, range hoods and exhaust fans. However, with the improvement of people's living standards and the development of science and technology, higher technical requirements are put forward for the multi-wing centrifugal fan. That is, to increase the flow rate of the multi-wing centrifugal fan, reduce energy consumption and improve the noise quality.

[0003] Research has found that when the multi-wing centrifugal fan is working, large flow separation will occur in the inner flow channel of the impeller. The main reason is that the pressure on the pressure surface of the blade is high and the speed is low, while the pressure on the suction surface is low and the speed is high. This pressure gradient causes the fluid to be subjected to a force pointing to the suction surface, resulting in the generation of vortices. In traditional methods, some researchers design the front and rear edges of the blade into a wavy or serrated structure, which can make the laminar boundary layer of the air flow turn into turbulent flow as early as possible, thus avoiding the flow separation caused by the unstable fluid micro-elements in the laminar boundary layer, and then reducing the performance loss of the fan and the fan noise. Other researchers open holes in the middle of the blade, which can make the gas on the pressure surface flow to the suction surface along the small holes during operation, balance the pressure difference on both sides, and then solve the vortex problem on the suction surface. However, the above methods reduce the work capacity of the corresponding area of the blade, and then the air volume and efficiency of the fan system. Summary of the Utility Model

[0004] The technical problem to be solved by the utility model is to overcome the defects that the existing blade has eddy current and low work efficiency, and to provide a fan blade, a fan and a range hood.

[0005] The utility model solves the above technical problem through the following technical solutions:

[0006] A fan blade, the fan blade includes a blade body and a flow splitting structure. The blade body has a suction surface and a pressure surface. The flow splitting structure is arranged on the outer peripheral side of the suction surface and is located at one side edge of the blade body close to the impeller middle disc. In the cross-sectional direction, the arc length of the flow splitting structure is 1 / 6 - 1 / 4 of the arc length of the blade body. The flow splitting structure is coaxially arranged with the blade body. The gap between the flow splitting structure and the blade body is δ, and the value range of δ is 1 / 10 - 1 / 5 of the gap between two adjacent blade bodies in the fan.

[0007] In this solution, by setting up a flow splitting structure and restricting the size of the flow splitting structure and the gap with the blade body, the vortex of the air flow is broken and split at the edge of the blade body close to the impeller middle disk, avoiding the formation of low-speed vortices on the suction surface, balancing the pressure difference between the pressure surface and the suction surface, so that when the air flow enters the area between the flow splitting structure and the blade body, the fluid flow velocity will increase due to the smaller cross-sectional area of this area, thus reducing the probability of vortex generation; a small pressure surface and suction surface area is formed between the flow splitting structure and the blade body, and the fluid passing through this area will shift towards the suction surface of the blade body under the action of inertia force and the pressure of the pressure surface of the flow splitting structure on the suction surface of the blade body, and then it will be closer to the suction surface boundary layer and is not easy to generate vortices; the mutual interference between the wake vortex generated by the flow splitting structure and the boundary layer on the upper boundary of the suction surface of the blade body can also achieve the purpose of suppressing flow separation to a certain extent, thereby improving the work efficiency of the fan blade, reducing the performance loss of the fan, and reducing the fan noise.

[0008] Preferably, one side edge of both ends of the blade body close to the impeller middle disk is the first side edge of the blade body, and the first side edge of the blade body is chamfered.

[0009] In this solution, through the above settings, the vortex breaking effect of the blade body is improved.

[0010] Preferably, two vertices are formed at the end of the chamfer away from the blade body, and the length of the flow splitting structure is the distance between the two vertices.

[0011] In this solution, through the above settings, the vortex breaking effect of the flow splitting structure is ensured.

[0012] Preferably, the first side edge of the flow splitting structure is flush with the first side edge of the blade body, and the second side edge of the flow splitting structure extends towards the second side edge of the blade body.

[0013] In this solution, through the above settings, it is ensured that the gas at the impeller inlet can play a flow splitting role when the impeller rotates and will not be blocked by the blade body for the inlet gas.

[0014] Preferably, the second side edge of the flow splitting structure is flush with the first side edge of the blade body, and the first side edge of the flow splitting structure extends along the direction away from the first side edge of the blade body.

[0015] In this solution, through the above settings, it is ensured that the gas flowing out from the inner flow channels of the flow splitting structure and the blade body can maintain a relatively high flow velocity on the suction surface of the blade body, so the flow splitting structure should not have a large position offset from the blade body.

[0016] Preferably, the first side edge of the blade body is located between the first side and the second side edges of the flow splitting structure.

[0017] In this solution, through the above settings, the interaction between the wake vortex generated by the flow splitting structure and the boundary layer on the suction surface of the blade body is realized, so as to achieve the purpose of suppressing flow separation.

[0018] Preferably, the flow splitting structure is provided with an installation groove corresponding to the impeller middle disc, and the installation groove penetrates through the flow splitting structure.

[0019] In this solution, through the above settings, interference between the flow splitting structure and the impeller middle disc is avoided.

[0020] Preferably, the second side edge of the blade body away from the flow splitting structure has a wavy structure, and the wavy structure extends along the length direction of the blade body.

[0021] In this solution, through the above settings, the flow velocity of the boundary layer fluid is increased to improve the noise quality of the fan.

[0022] A fan, the fan includes the fan blade as described above.

[0023] In this solution, the fan includes the above-mentioned fan blade, so that the noise of the fan is smaller than that of the traditional fan. In addition, through the above-mentioned fan blade, vortex breaking and flow splitting are carried out to reduce the generation probability of low-speed vortices, and at the same time, the purpose of suppressing flow separation can be achieved, which is beneficial to improving the work capacity of the fan blade, thereby reducing the flow loss of the fan, increasing the air volume and efficiency of the fan system, and correspondingly reducing the noise of the fan.

[0024] An oil fume extractor, the oil fume extractor includes the fan as described above.

[0025] In this solution, the oil fume extractor includes the above-mentioned fan, so that the oil fume extractor has less noise and higher oil fume extraction efficiency during use.

[0026] The positive and progressive effects of the present utility model are as follows: By setting a flow splitting structure and restricting the size of the flow splitting structure and the gap between the flow splitting structure and the blade body, the present utility model breaks the vortex and splits the airflow at the edge of the blade body close to the impeller middle disc, avoiding the formation of low-speed vortices on the suction surface, balancing the pressure difference between the pressure surface and the suction surface, so that when the airflow enters the area between the flow splitting structure and the blade body, the fluid flow velocity will increase because the cross-sectional area of this area is small, thus reducing the probability of vortex generation; A small pressure surface and suction surface area is formed between the flow splitting structure and the blade body. The fluid passing through this area will shift towards the suction surface of the blade body under the action of inertial force and the pressure of the pressure surface of the flow splitting structure on the suction surface of the blade body, and then adhere more closely to the suction surface boundary layer, making it not easy to generate vortices; The mutual interference between the wake vortex generated by the flow splitting structure and the upper boundary layer on the suction surface of the blade body can also achieve the purpose of suppressing flow separation to a certain extent, thereby improving the work efficiency of the fan blade, reducing the performance loss of the fan, and reducing the fan noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a diagram showing the positional relationship between the fan blade and the impeller middle disc of a preferred embodiment of the present utility model.

[0028] Figure 2 It is a perspective view of the fan blade of a preferred embodiment of the present utility model.

[0029] Figure 3 It is a schematic diagram showing the alignment of the first side of the flow splitting structure with the first side edge of the blade body in a preferred embodiment of the present utility model.

[0030] Figure 4 It is a schematic diagram showing the alignment of the second side of the flow splitting structure with the first side edge of the blade body in a preferred embodiment of the present utility model.

[0031] Figure 5 It is a schematic diagram showing the structure of the first side and the second side of the flow splitting structure located between the first side edges of the blade body in a preferred embodiment of the present utility model.

[0032] Figure 6 It is a schematic diagram of the fan flow field of the present utility model.

[0033] DESCRIPTION OF REFERENCE NUMERALS:

[0034] Blade body 10

[0035] Suction surface 11

[0036] Pressure surface 12

[0037] Vertex 13

[0038] Flow splitting structure 20

[0039] Installation groove 21

[0040] Support member 22

[0041] Impeller middle plate 30

[0042] Wave-shaped structure 40

[0043] Volute 50

[0044] Volute tongue 51 Specific implementation mode

[0045] The following is a preferred embodiment, and the accompanying drawings are used to more clearly and completely illustrate the present invention.

[0046] This embodiment provides a fan blade, and the specific structure is as Figure 1 and Figure 2 shown. The fan blade includes a blade body 10 and a flow splitting structure 20. The blade body 10 has a suction surface 11 and a pressure surface 12. The flow splitting structure 20 is arranged on the outer peripheral side of the suction surface 11, and the flow splitting structure 20 is located at one side edge of the blade body 10 close to the impeller middle plate 30. In the cross-sectional direction, the arc length of the flow splitting structure 20 is 1 / 6 - 1 / 4 of the arc length of the blade body 10. The flow splitting structure 20 is coaxially arranged with the blade body 10. The gap between the flow splitting structure 20 and the blade body 10 is δ, and the value range of δ is 1 / 10 - 1 / 5 of the gap between two adjacent blade bodies 10 in the fan.

[0047] Specifically, the blade body 10 is a sheet metal, and the cross-section of the blade body 10 is an arc structure. The blade body 10 is made by sheet metal processing. The side of the blade body 10 away from the opening of the arc structure is the suction surface 11, and the side facing the opening of the arc structure is the pressure surface 12, that is, the side of the blade body 10 facing the impeller hub 30 is the pressure surface 12. A plurality of blade bodies 10 are arranged at intervals around the axis of the impeller hub 30. This is the prior art and will not be elaborated here. Among them, the flow splitting structure 20 is also a sheet metal with an arc-shaped cross-section. The center of the flow splitting structure 20 is the same as that of the blade body 10. Taking the radius of the blade body 10 as R, the radius of the flow splitting structure 20 is R + δ, and the value range of δ is 1 / 10 to 1 / 5 of the gap between two adjacent blade bodies 10 in the fan. The gap between two adjacent blade bodies 10 in the fan can be determined according to the actual fan model. This is the prior art and will not be elaborated here. The flow splitting structure 20 is located on the outer peripheral side of the blade body 10 and is arranged on the edge of the suction surface 11 close to the impeller hub 30, that is, the first side edge of the blade body 10. By arranging the flow splitting structure 20 on the blade body 10, the edge of the blade body 10 close to the impeller hub 30 can break the vortex and split the airflow, avoiding the formation of low-speed vortices on the suction surface 11 and balancing the pressure difference between the pressure surface 12 and the suction surface 11. Compared with the method of opening holes on the blade body 10 to balance the pressure difference, it will not damage the blade body 10 and at the same time prevent the work capacity of the fan blade on the gas from becoming weak.

[0048] Furthermore, the arc length of the flow splitting structure 20 is 1 / 6 to 1 / 4 of the arc length of the blade body 10. By restricting the arc length of the flow splitting structure 20, when the airflow enters the area between the flow splitting structure 20 and the blade body 10, due to the small cross-sectional area of this area, the fluid flow velocity will increase, so the probability of vortex generation will be reduced; a small pressure surface and suction surface area is formed between the flow splitting structure 20 and the blade body 10. The fluid passing through this area will shift towards the suction surface 11 of the blade body 10 under the action of inertia force and the pressure of the pressure surface of the flow splitting structure 20 on the suction surface 11 of the blade body 10, and thus get closer to the boundary layer of the suction surface 11 and is not easy to generate vortices; the mutual interference between the wake vortex generated by the flow splitting structure 20 and the boundary layer on the suction surface 11 of the blade body 10 can also achieve the purpose of suppressing flow separation to a certain extent, thereby improving the work efficiency of the fan blade, reducing the performance loss of the fan, and reducing the fan noise. It can be understood that in this embodiment, the curvature of the flow splitting structure 20 is the same as that of the blade body 10. The arc length of the blade body 10 can be determined according to the actual fan model. This is the prior art and will not be elaborated here.

[0049] In this embodiment, the edges of both ends of the blade body 10 close to the impeller hub 30 are the first side edges of the blade body 10, and chamfering treatment is performed on the first side edges of the blade body 10.

[0050] Specifically, the chamfer is a chamfering process in the prior art to add a chamfer to the first side edge of the blade body 10, so as to accelerate the fluid flow velocity of the boundary layer at this position and cooperate with the flow splitting structure 20 to improve the vortex breaking effect of the blade body 10.

[0051] In this embodiment, two vertices 13 are formed at the end of the chamfer away from the blade body 10, and the length of the flow splitting structure 20 is the distance between the two vertices 13.

[0052] Specifically, chamfers are provided at both ends of the blade body 10 corresponding to the first side edge of the blade body 10. The vertex 13 of the chamfer is away from the second side edge of the blade body 10. The blade body 10 has two ends, and the number of corresponding vertices 13 is two. The length of the flow splitting structure 20 is the distance between the two vertices 13 to limit the length of the flow splitting structure 20 to ensure the vortex breaking effect of the flow splitting structure 20. It can be understood that the limitation of the length of the flow splitting structure 20 can also avoid the structural interference between the flow splitting structure 20 and the front and rear discs of the impeller. The distance between the two vertices 13 can be determined according to the actual fan model, which is the prior art and will not be elaborated here.

[0053] As Figure 3 shown, in this embodiment, the first side edge of the flow splitting structure 20 is flush with the first side edge of the blade body 10, and the second side edge of the flow splitting structure 20 extends toward the second side edge of the blade body 10.

[0054] Specifically, taking the center of the blade body 10 as O, the radius of the blade body 10 as R, and the radius of the flow splitting structure 20 as R + δ, and taking the first side edge of the flow splitting structure 20 as b, the second side edge as c, and the first side edge of the blade body 10 as a as an example. From the cross-section, when the first side edge of the flow splitting structure 20 is flush with the first side edge of the blade body 10, O, a, and b are on the same straight line, and the second side edge c of the flow splitting structure 20 extends from the first side edge of the blade body 10 toward the second side edge of the blade body 10, that is, the flow splitting structure 20 does not protrude from the first side edge of the blade body 10, so as to ensure that the gas at the impeller inlet can play a flow splitting role when the impeller rotates and will not be blocked by the blade body 10 for the inlet gas. It can be understood that this is the relative position of the flow splitting structure 20 and the blade body 10 under the extreme working condition to facilitate improving the flow splitting effect on the air flow.

[0055] As Figure 4 shown, in another embodiment, the second side edge of the flow splitting structure 20 is flush with the first side edge of the blade body 10, and the first side edge of the flow splitting structure 20 extends along the direction away from the first side edge of the blade body 10.

[0056] Specifically, taking the first side edge of the flow splitting structure 20 as b, the second side edge as c, and the first side edge of the blade body 10 as a as an example for illustration. Among them, when viewed from the cross-section, when the second side edge of the flow splitting structure 20 is flush with the first side edge of the blade body 10, O, a, and c are on the same straight line, while the first side edge c of the flow splitting structure 20 extends along the direction away from the first side edge of the blade body 10, that is, the flow splitting structure 20 protrudes from the first side edge of the blade body 10. Furthermore, it can ensure that the gas flowing out from the inner flow channels of the flow splitting structure 20 and the blade body 10 can maintain a relatively high flow velocity on the suction surface 11 of the blade body 10. Therefore, the flow splitting structure 20 should not have a large position offset from the blade body 10. It can be understood that this is the relative position of the flow splitting structure 20 and the blade body 10 under the extreme working condition, so as to improve the air flow velocity on the suction surface 11.

[0057] As Figure 5 shown, in other embodiments, the first side edge of the blade body 10 is located between the first side edge and the second side edge of the flow splitting structure 20.

[0058] Specifically, taking the first side edge of the flow splitting structure 20 as b, the second side edge as c, and the first side edge of the blade body 10 as a as an example for illustration. Among them, when viewed from the cross-section, when the first side edge of the blade body 10 is located between the first side edge and the second side edge of the flow splitting structure 20, the connection line Oa is located between the connection lines Ob and Oc, that is, the flow splitting structure 20 protrudes from the first side edge of the blade body 10 and is not in the setting position under the extreme working condition. Furthermore, the interaction between the wake vortex generated by the flow splitting structure 20 and the boundary layer on the upper boundary of the suction surface 11 of the blade body 10 is realized, so as to achieve the purpose of suppressing flow separation. It should be noted that the setting positions of the flow splitting structure 20 and the blade body 10 are obtained through analysis and tests using finite element software in the prior art. This is the prior art and will not be elaborated here.

[0059] In this embodiment, the flow splitting structure 20 is provided with an installation groove 21 corresponding to the impeller middle disk 30, and the installation groove 21 penetrates through the flow splitting structure 20.

[0060] Specifically, the installation groove 21 has the same edge shape as the impeller middle disk 30, and the installation groove 21 penetrates along the chord length direction of the flow splitting structure 20 to divide the flow splitting structure 20 into two parts. Each part of the flow splitting structure 20 is connected to the suction surface 11 of the blade body 10 through a support member 22 to prevent the flow splitting structure 20 from separating from the blade body 10. By providing the installation groove 21, interference between the flow splitting structure 20 and the impeller middle disk 30 can be avoided.

[0061] In this embodiment, the second side edge of the blade body 10 away from the flow splitting structure 20 has a wavy structure 40, and the wavy structure 40 extends along the length direction of the blade body 10.

[0062] Specifically, the wavy structure 40 is arranged on the second side edge of the blade body 10 and is integrally formed with the blade body 10. The wavy structure 40 is a structure on a fan blade in the prior art, so as to cooperate with the flow splitting structure 20 to increase the fluid flow velocity of the boundary layer and improve the noise quality of the fan.

[0063] As Figure 6 shown, this embodiment also provides a fan, and the fan includes the above-mentioned fan blade.

[0064] Specifically, the fan includes an impeller and a volute 50. The impeller is arranged inside the volute 50. The volute 50 has a volute tongue 51. An impeller middle disc 30 and a blade body 10 are arranged on the impeller. A flow splitting structure 20 is arranged on one side edge of the blade body 10 close to the impeller middle disc 30. Compared with the blade body 10 of the traditional one without the flow splitting structure 20, after the air flow enters from the inlet of the fan, there are fewer low-speed vortices on the suction surface 11, the air flow in the fan flow field is more uniform, the work efficiency of the fan blade is higher, and after the fluid is vortex broken and flow split by the fan blade, the flow field flow in the volute 50 is more uniform, achieving the purpose of suppressing flow separation. Correspondingly, the noise of the fan is smaller than that of the traditional fan, reducing the flow loss of the fan, and the air volume and efficiency of the fan system are correspondingly improved.

[0065] This embodiment also provides a range hood, and the range hood includes the above-mentioned fan. The range hood includes the above-mentioned fan, so that the range hood has less noise and higher oil fume suction efficiency during use.

[0066] Although the specific implementation manners of the present invention have been described above, those skilled in the art should understand that this is only for illustration purposes. The protection scope of the present invention is defined by the appended claims. Without departing from the principle and essence of the present invention, those skilled in the art can make various changes or modifications to these implementation manners, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A fan blade, characterized in that: The fan blade includes a blade body and a diverter structure, the blade body has a suction surface and a pressure surface, the diverter structure is arranged on the outer peripheral side of the suction surface, and the diverter structure is arranged at the edge of one side of the blade body close to the impeller center disk, along the cross-sectional direction, the arc length of the diverter structure is 1 / 6 to 1 / 4 of the arc length of the blade body, the diverter structure is coaxially arranged with the blade body, the gap between the diverter structure and the blade body is δ, and the value range of δ is 1 / 10 to 1 / 5 of the gap between two adjacent blade bodies in the fan.

2. The fan blade according to claim 1, characterized in that: One side edge of the two ends of the blade body close to the impeller center disk is the first side edge of the blade body, and the first side edge of the blade body is chamfered.

3. The fan blade according to claim 2, characterized in that: The end of the cut angle away from the blade body forms two vertices, and the length of the flow splitting structure is the distance between the two vertices.

4. The fan blade according to claim 3, characterized in that: The first side edge of the flow splitting structure is arranged flush with the first side edge of the blade body, and the second side edge of the flow splitting structure extends toward the second side edge of the blade body.

5. The fan blade according to claim 3, characterized in that: The second side edge of the flow splitting structure is arranged flush with the first side edge of the blade body, and the first side edge of the flow splitting structure extends in a direction away from the first side edge of the blade body.

6. The fan blade according to claim 3, characterized in that: The first side edge of the blade body is located between the first side and the second side edge of the flow dividing structure.

7. The fan blade according to claim 1, characterized in that: The flow-dividing structure is provided with a mounting groove corresponding to the impeller center disk, and the mounting groove runs through the flow-dividing structure.

8. The fan blade according to claim 1, characterized in that: The second side edge of the blade body away from the diverter structure has a wavy structure, and the wavy structure extends along the length direction of the blade body.

9. A fan, characterized in that: The wind fan comprises the wind fan blade according to any one of claims 1-8.

10. A range hood, characterized in that: The range hood comprises the fan as claimed in claim 9.

Images