Centrifugal fan and volute assembly

Abstract

The disclosure provides a centrifugal fan and a volute assembly, the volute assembly comprising a volute and an impeller mounted inside the volute; a diffuser passage is arranged in the volute, the bottom disc angle of the impeller is the same as the diffuser angle of the diffuser passage; the first end of the diffuser passage is communicated with the bottom disc of the impeller, the second end of the diffuser passage is communicated with the outside of the volute, the airflow enters the diffuser passage from the first end, the ratio of the height increment of the diffuser passage from the first end to the second end to the arc length increment of the diffuser passage along the center line corresponds to the tangent value of the diffuser angle, by arranging the diffuser passage in the volute assembly, when the centrifugal fan is applied to small household appliances which cannot adopt spiral type line design, the diffuser passage in the volute assembly effectively improves the static pressure capacity and air volume of the centrifugal fan, and reduces the air noise of the centrifugal fan.

Description

Technical Field

[0001] This disclosure relates to the field of household appliance technology, and in particular to a centrifugal fan and volute assembly. Background Technology

[0002] Centrifugal fans are frequently used in various home appliances, such as the air pumps in range hoods, dishwashers' bubble wash function, and robot vacuum motors. However, the volutes of most commercially available centrifugal fans typically employ a spiral design. Airflow passes through the impeller, is collected and pressurized by the volute, and then guided outside the centrifugal fan. However, when centrifugal fans are used in smaller appliances, the compact design often limits space, preventing the use of a spiral design in the centrifugal fan's volute. This results in higher aerodynamic noise within the centrifugal fan. Summary of the Invention

[0003] The technical problem to be solved by this disclosure is to overcome the defect that the spiral design of the volute of small household appliances in the prior art cannot be adopted, resulting in large aerodynamic noise in the centrifugal fan, and to provide a centrifugal fan and volute assembly.

[0004] This disclosure solves the above-mentioned technical problems through the following technical solution:

[0005] In a first aspect, embodiments of this disclosure provide a volute assembly, the volute assembly including a volute and an impeller installed inside the volute;

[0006] The volute is provided with a diffuser channel, and the chassis tilt angle of the impeller is the same as the diffuser angle of the diffuser channel.

[0007] The first end of the diffuser channel is connected to the chassis of the impeller, and the second end of the diffuser channel is connected to the outside of the volute. The airflow enters the diffuser channel from the first end. The ratio of the height increment of the diffuser channel from the first end to the second end to the arc length increment of the diffuser channel along the center line is equivalent to the tangent of the diffuser angle.

[0008] Optionally, the height increment of the diffuser channel from the first end to the second end is determined based on the radial velocity of the airflow propagating in the diffuser channel.

[0009] Optionally, the height increment of the diffuser channel from the first end to the second end satisfies:

[0010] ΔH=v r ·Δt;

[0011] Wherein, ΔH is the height increment of the diffusion channel from the first end to the second end, and v r The radial velocity of the airflow is given, and Δt is the propagation time of the airflow in the diffuser channel.

[0012] Optionally, the radial velocity of the airflow is determined based on the chassis tilt angle, including:

[0013] v r =v out sinα;

[0014] Wherein, the v r The radial velocity of the airflow, v out The velocity of the airflow entering the diffuser channel from the first end is α, and the chassis tilt angle is α.

[0015] Optionally, the increment of the diffuser channel along the centerline arc length is determined based on the propagation of the airflow tangentially within the diffuser channel.

[0016] Optionally, the incremental length of the diffuser channel along the centerline arc direction satisfies:

[0017] ΔL=v θ ·Δt;

[0018] Wherein, ΔH is the height increment of the diffusion channel from the first end to the second end, and v θ The tangential velocity of the airflow is given, and Δt is the propagation time of the airflow in the diffuser channel.

[0019] Optionally, the tangential velocity of the airflow is determined based on the chassis tilt angle, including:

[0020] v θ =v out ·cosα;

[0021] Wherein, the v θ v is the tangential velocity of the airflow. out The velocity of the airflow entering the diffuser channel from the first end is α, and the chassis tilt angle is α.

[0022] Optionally, the diffusion angle is within the range of 5° to 12°.

[0023] Optionally, the profile of the volute can be a circular profile or a spiral profile.

[0024] In a second aspect, embodiments of this disclosure provide a centrifugal fan, the centrifugal fan including the volute assembly as described in the first aspect.

[0025] Optionally, the centrifugal fan further includes a motor for driving the impeller to rotate and generate airflow.

[0026] Thirdly, embodiments of this disclosure provide a smart appliance, which includes a centrifugal fan as described in the second aspect.

[0027] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of this disclosure.

[0028] The positive improvements of this disclosure are as follows: By incorporating a diffuser channel within the volute assembly, when a centrifugal fan is used in small household appliances where a spiral design is not feasible, the diffuser channel effectively controls the velocity distribution of the airflow discharged from the volute, mitigating the potential for excessive velocity at the volute outlet, recovering the dynamic pressure at the volute outlet, enhancing the centrifugal fan's static pressure carrying capacity and airflow, and reducing fan noise. Furthermore, in the design of the diffuser channel, the ratio of the height increment from the first end to the second end to the arc length increment along the centerline is equivalent to the tangent of the diffuser angle. Since the velocity component of the airflow within the diffuser channel is affected by the chassis tilt angle, coupling the impeller's chassis tilt angle with the diffuser channel's diffuser angle in the design yields a scheme where the chassis tilt angle and diffuser angle are identical, further reducing aerodynamic efficiency loss and aerodynamic noise. Attached Figure Description

[0029] Figure 1 A top cross-sectional view of a volute assembly provided for an exemplary embodiment of this disclosure;

[0030] Figure 2 A front cross-sectional view of a volute assembly provided for an exemplary embodiment of this disclosure;

[0031] Figure 3 A partially enlarged view of a volute assembly provided for an exemplary embodiment of this disclosure;

[0032] Figure 4 Rear view of a volute assembly provided for an exemplary embodiment of this disclosure. Detailed Implementation

[0033] The present disclosure is further illustrated below by way of embodiments, but the present disclosure is not limited to the scope of the embodiments described herein.

[0034] The prefixes such as "first" and "second" used in this disclosure are merely for distinguishing different descriptive objects and do not limit the position, order, priority, quantity, or content of the described objects. The use of ordinal numbers and other prefixes used to distinguish descriptive objects in this disclosure does not constitute a limitation on the described objects. The description of the described objects is given in the claims or the context of the embodiments, and should not be construed as an unnecessary limitation. Furthermore, in the description of this embodiment, unless otherwise stated, "multiple" means two or more.

[0035] In this embodiment of the disclosure, the collection, storage, use, processing, transmission, provision, and disclosure of user personal information comply with relevant laws and regulations and do not violate public order and good morals.

[0036] An exemplary embodiment of this disclosure provides a volute assembly, such as Figure 1-4 As shown, the volute assembly includes a volute 10 and an impeller 20 installed inside the volute 10.

[0037] Specifically, the volute 10 serves to concentrate and guide the gas leaving the impeller 20 and further convert some of the kinetic energy into static pressure. The design of the volute 10 typically includes two parts: the diffuser channel 11 and the volute tongue.

[0038] The diffuser channel 11 is disposed on the volute 10 and is connected to the outlet of the impeller 20. The first end of the diffuser channel 11 is connected to the chassis 22 of the impeller 20, and the second end of the diffuser channel 11 is connected to the outside of the volute 10.

[0039] The blades 21 of the impeller 20 are distributed circumferentially on the chassis 22 of the impeller 20. An air inlet is provided on the volute 10 at the position opposite to the blades 21. Under the action of the impeller 20, the airflow enters the volute 10. The airflow generated by the impeller 20 enters the diffuser channel 11 from the first end of the diffuser channel 11, and then exits the fan through the diffuser channel 11. The height of the diffuser channel 11 increases from the first end to the second end. The port at the second end of the diffuser channel 11 is equivalent to the outlet of the volute assembly.

[0040] Under normal circumstances, the speed distribution of the airflow discharged from the volute 10 can be effectively controlled by the height design and diffusion degree of the diffusion channel 11, which solves the hidden danger of excessive airflow velocity at the outlet of the volute 10, recovers the outlet dynamic pressure of the volute 10, improves the static pressure carrying capacity and air volume of the fan, and reduces wind noise.

[0041] However, if the parameters of the diffuser channel 11 in the volute 10 are not coupled and designed, the effect of the diffuser channel 11 cannot be maximized, and a small amount of aerodynamic loss and wind noise will still be generated.

[0042] Therefore, in this embodiment, the following design is further specified: the tilt angle of the impeller 20's chassis 22 is the same as the diffusion angle of the diffusion channel 11, and the ratio of the height increment of the diffusion channel 11 from the first end to the second end to the arc length increment of the diffusion channel 11 along the centerline is equivalent to the tangent of the diffusion angle. The tilt angle of the chassis 22 is the angle between the plane of the chassis 22 and the horizontal plane.

[0043] The design process of the diffuser channel 11 will be further elaborated below. The design of the diffuser channel 11 takes into account the diffusion rate of the diffuser channel 11 and the changes of each velocity component of the airflow in the diffuser channel 11:

[0044] When the airflow enters the diffuser 11 from the first end of the diffuser 11, considering the influence of the chassis 22 tilt angle on the tangential and radial velocities of the airflow entering the diffuser 11, we can obtain:

[0045] v θ =v out ·cosα (1)

[0046] v r =v out ·sinα (2)

[0047] Among them, v out v is the velocity of the airflow entering the diffuser channel 11 from the first end. r v is the radial velocity of the airflow. θ Let α be the tangential velocity of the airflow, and α be the chassis tilt angle 22.

[0048] Meanwhile, the height increment ΔH from the first end to the second end of the diffuser channel 11, and the increment ΔL along the arc length of the centerline of the diffuser channel 11, usually determine the diffusion rate of the diffuser channel 11. In the design of the diffuser channel 11, the diffuser channel 11 must satisfy the law of flow conservation and the optimal diffusion angle constraint to avoid boundary layer separation of the airflow due to excessively fast diffusion.

[0049] According to the law of conservation of flow rate, under conditions of incompressible fluid (such as air at room temperature), the flow volume within a certain section of the duct must be conserved. That is, the flow volume entering diffuser channel 11 is the same as the flow volume exiting diffuser channel 11. Therefore:

[0050] v out ·H in =v exit ·(H in +ΔH) (3)

[0051] Among them, H in H represents the height of the channel at the first end. in +ΔH is the channel height at the second end, v exit The velocity of the airflow exiting the diffuser channel 11 from the second end.

[0052] Based on the diffusion angle constraint, the height increment gradient of the diffusion channel 11 (which can be understood as the ratio of the height increment of the diffusion channel 11 from the first end to the second end in this embodiment to the increment along the arc length of the diffusion channel 11 along the centerline, i.e., ΔH / ΔL) satisfies the diffusion angle constraint, thus avoiding airflow loss due to excessive expansion within the volute 10. Therefore, we can obtain:

[0053] ΔH / ΔL=tanθ opt (4)

[0054] In one embodiment, θ opt The optimal diffusion angle is within the range of 5° to 12°.

[0055] The height increment of the diffuser channel 11 from the first end to the second end is determined based on the radial velocity of the airflow propagation in the diffuser channel 11, from which we can obtain:

[0056] ΔH=v r ·Δt (5)

[0057] Where ΔH is the height increment of the diffusion channel 11 from the first end to the second end, v r Δt is the radial velocity of the airflow, and Δt is the propagation time of the airflow in the diffuser channel 11.

[0058] The increment of the diffuser channel 11 along the centerline arc length is determined based on the propagation of the tangential velocity of the airflow in the diffuser channel 11, from which we can obtain:

[0059] ΔL=v θ ·Δt (6)

[0060] Where ΔH is the height increment of the diffusion channel 11 from the first end to the second end, v θ Δt is the tangential velocity of the airflow, and Δt is the propagation time of the airflow in the diffuser channel 11.

[0061] By simultaneously solving equations (1) to (6), we can obtain: α = θ opt (That is, the tilt angle of the chassis 22 of the impeller 20 is the same as the diffusion angle of the diffuser channel 11), and H out =H in +ΔL·tanθ opt (That is, the ratio of the height increment of the diffuser channel 11 from the first end to the second end to the increment of the diffuser channel 11 along the arc length of the center line is equivalent to the tangent of the diffuser angle).

[0062] Finally, the rationality of the diffuser channel 11 obtained in the above design is verified again by the law of conservation of flow, and the following results are obtained:

[0063] v out ·H in =v exit ·H out (7)

[0064] Among them, H out v represents the height of the channel at the second end. exit The velocity of the airflow exiting the diffuser channel 11 from the second end.

[0065] At the second end of the diffuser channel 11, the total energy of the airflow includes: kinetic energy (related to velocity vexit), target static pressure, etc. According to the law of conservation of energy, the energy at the first and second ends of the diffuser channel 11 is the same, that is, for v... exit satisfy:

[0066] P s +0.5·ρ·v exit 2 =v out 2 (8)

[0067] Among them, P s ρ is the target static pressure that the airflow needs to reach after passing through the diffuser channel 11, and ρ is the air density.

[0068] The volute assembly obtained through the above design has a static pressure uniformity at the outlet of the second end σP≤5% and a volute tongue pressure pulsation ΔP≤0.2Ps.

[0069] In one embodiment, the profile of the volute 10 is either a circular or a spiral. In this embodiment, no specific application scenario is set for the volute assembly. In some larger household appliances, a spiral profile can be used to further meet the requirements of reducing aerodynamic losses and aerodynamic noise of the centrifugal fan, while in some smaller household appliances, a circular profile can be used to reduce the size of the centrifugal fan.

[0070] In one embodiment, a guide vane is also provided inside the volute 10. The guide vane is disposed on the annular wall of the volute 10 and spaced apart on the outer periphery of the impeller 20, and preferably the whole can be arc-shaped. By providing the guide vane, the development of secondary flow when the impeller airflow flows out of the impeller 20 and the losses caused by flow channel diffusion during the expansion of the volute 10 can be reduced.

[0071] In this embodiment, by setting a diffuser channel in the volute assembly, when the centrifugal fan is used in small household appliances where a spiral design cannot be adopted, the diffuser channel in the volute assembly effectively controls the velocity distribution of the airflow discharged from the volute, solving the hidden danger of excessive airflow velocity at the volute outlet, recovering the outlet dynamic pressure of the volute, improving the centrifugal fan's static pressure carrying capacity and airflow, and reducing the centrifugal fan's wind noise. Simultaneously, in the design of the diffuser channel, the ratio of the height increment of the diffuser channel 11 from the first end to the second end to the increment along the arc length of the diffuser channel along the centerline is equivalent to the tangent of the diffuser angle. Furthermore, since the velocity component of the airflow within the diffuser channel is affected by the chassis tilt angle, the chassis tilt angle of the impeller is coupled with the diffuser angle of the diffuser channel, resulting in a scheme where the chassis tilt angle and the diffuser angle are the same, further reducing aerodynamic efficiency loss and aerodynamic noise.

[0072] An exemplary embodiment of this disclosure also provides a centrifugal fan, which includes the volute assembly as described in the above embodiments.

[0073] Specifically, the centrifugal fan also includes a motor, which is located outside the volute assembly and connected to the impeller 20 located inside the volute 10 through an opening on the volute 10. The motor is used to drive the impeller 20 to rotate and generate airflow.

[0074] An exemplary embodiment of this disclosure also provides a smart appliance, which includes the centrifugal fan as described in the above embodiments. The smart appliance may include, but is not limited to, any electrical device such as a range hood, air conditioner, or blower.

[0075] Specifically, the smart appliance equipped with a centrifugal fan has a smart voice control module. The smart voice control module includes a controller, a voice receiving module, and a voice parsing module. The voice receiving module receives user commands, and the voice parsing module parses the commands. Based on the parsed commands, the controller is electrically connected to the motor of the centrifugal fan. The controller controls the airflow through the motor, thereby realizing intelligent regulation of the airflow of the smart appliance and improving the user experience of using the smart appliance.

Claims

1. A volute assembly, characterized in that, The volute assembly includes a volute and an impeller installed inside the volute; The volute is provided with a diffuser channel, and the chassis tilt angle of the impeller is the same as the diffuser angle of the diffuser channel. The first end of the diffuser channel is connected to the chassis of the impeller, and the second end of the diffuser channel is connected to the outside of the volute. The airflow enters the diffuser channel from the first end. The ratio of the height increment of the diffuser channel from the first end to the second end to the height increment of the diffuser channel along the arc length of the center line is equivalent to the tangent of the diffuser angle. The height increment of the diffuser channel from the first end to the second end is determined based on the radial velocity of the airflow propagating in the diffuser channel; The radial velocity of the airflow is determined based on the chassis tilt angle, including: v r =v out ·sinα; Wherein, the v r The radial velocity of the airflow, v out The velocity of the airflow entering the diffuser channel from the first end is α, and the chassis tilt angle is α. The increment of the diffuser channel along the centerline arc length is determined based on the propagation of the airflow at the tangential velocity within the diffuser channel; The tangential velocity of the airflow is determined based on the chassis tilt angle, including: v θ =v out ·cosα; Wherein, the v θ v is the tangential velocity of the airflow. out The velocity of the airflow entering the diffuser channel from the first end is α, and the chassis tilt angle is α.

2. The volute assembly as described in claim 1, characterized in that, The height increment of the diffusion channel from the first end to the second end satisfies: ΔH=v r ·Δt; Wherein, ΔH is the height increment of the diffusion channel from the first end to the second end, and v r The radial velocity of the airflow is given, and Δt is the propagation time of the airflow in the diffuser channel.

3. The volute assembly as described in claim 1, characterized in that, The incremental length of the diffusion channel along the centerline arc direction satisfies: ΔL=v θ ·Δt; Wherein, ΔH is the height increment of the diffusion channel from the first end to the second end, and v θ The tangential velocity of the airflow is given, and Δt is the propagation time of the airflow in the diffuser channel.

4. The volute assembly as claimed in claim 1, characterized in that, The diffusion angle is within the range of 5° to 12°. And / or, the profile of the volute is a circular profile or a spiral profile.

5. A centrifugal fan, characterized in that, The centrifugal fan includes the volute assembly as described in any one of claims 1-4.

6. The centrifugal fan as described in claim 5, characterized in that, The centrifugal fan also includes a motor, which drives the impeller to rotate and generate airflow.

Images