Impeller, fan with impeller and range hood with impeller

Abstract

The impeller comprises a front disc, a rear disc and blades arranged between the front disc and the rear disc, the tops of the blades are fixed to the front disc, the bottoms of the blades are fixed to the rear disc, and each blade is provided with a front edge and a tail edge; at least two holes are formed in the positions, close to the tops of the blades, of the blades, and the holes are formed between the front edges and the tail edges of the blades at intervals. Compared with the prior art, the impeller has the advantages that the holes are formed in the positions close to the tops of the blades, pressure difference of the two sides of the blades is formed, flow vortexes are generated, the flow vortexes suck main flow in and interact with a wake shear layer, large-scale vortex structures in wakes are broken, shedding of the vortexes on the tops of the blades is reduced, and the impeller is more stable in performance. The total pressure higher than that of a prototype fan can be obtained, and better aerodynamic performance is achieved.

Description

Technical Field

[0001] The utility model relates to a power device, in particular to an impeller, a fan using the impeller, and a range hood using the fan. Background Art

[0002] In the new generation of thin range hoods, the air inlet space is relatively narrow. The existence of the air inlet panel causes more turbulence. The distance between the fan air inlet and the panel is close, which blocks part of the air inlet circle, weakening the overall guide effect of the air inlet circle and causing more vortices in the impeller part.

[0003] In the prior art, serrations are usually provided on the leading edge of the blade to solve the problem. For example, the Chinese patent application number 201820922809.3 discloses a serrated blade for a centrifugal fan, in which a serrated structure is formed on the leading edge of the blade body. In the case of poor air intake in a thin fan, the instability in the impeller flow will develop and increase in the boundary layer and radiate sound at the trailing edge. When simply using blade serrations, the amplitude and phase of the velocity loss of the front blade wake will produce obvious oscillations along the span of the rotor, which will produce a roaring sound.

[0004] When the air intake section is blocked, the comb-like structure of the blades can reduce the noise in the low-frequency range of the airfoil, while the noise in the high-frequency range will increase. Therefore, when the air intake is blocked, the control effect of the leading edge serration structure will be weakened, and the simple and small leading edge serration is not suitable for thin range hoods. Utility Model Content

[0005] The first technical problem to be solved by the utility model is to provide an impeller capable of breaking large vortices into small vortices and reducing aerodynamic noise in view of the deficiencies in the above-mentioned prior art.

[0006] The second technical problem to be solved by the utility model is to provide a fan using the above impeller.

[0007] The third technical problem to be solved by the utility model is to provide a range hood using the above-mentioned fan.

[0008] The technical solution adopted by the utility model to solve the first technical problem is: an impeller, comprising a front disc, a rear disc and a blade arranged between the front disc and the rear disc, the top of the blade is fixed to the front disc, the bottom of the blade is fixed to the rear disc, and the blade has a leading edge and a trailing edge; the characteristics are:

[0009] A hole is formed on the blade near the top of the blade. There are at least two holes which are arranged at intervals between the leading edge and the trailing edge of the blade.

[0010] By opening a hole near the top of the blade, a pressure difference is formed on both sides of the blade, generating a streamwise vortex. The streamwise vortex draws in the mainstream and interacts with the wake shear layer, breaking up the large-scale vortex structure in the wake. The vortex shedding at the top of the blade is reduced, and a higher total pressure than the prototype fan can be obtained, with better aerodynamic performance.

[0011] Furthermore, the hole is elliptical, the major axis of the ellipse extends between the leading edge and the trailing edge of the blade, and the minor axis of the ellipse extends in the axial direction of the impeller. Thus, the elliptical hole can be used to suppress the development of vorticity along the normal direction of the blade surface and accelerate the energy attenuation of the trailing edge along the flow direction.

[0012] Furthermore, a first sawtooth is formed on the leading edge of the blade, and the first sawtooth is located between the hole and the top of the blade, thereby further breaking the large vortex into small vortices.

[0013] Furthermore, a second sawtooth is provided at the root of the first sawtooth, and the size of the first sawtooth is larger than that of the second sawtooth. The second sawtooth within the first sawtooth accelerates the flow velocity of the fluid, can better weaken the energy of the separation vortex, and the large-scale vortex is gradually broken into small-scale vortices, and the vortex system structure is more compact.

[0014] Preferably, the first sawtooth and the second sawtooth are both triangular sawtooth.

[0015] Furthermore, a groove is formed at the trailing edge of the blade near the bottom of the blade, thereby reducing turbulence at the trailing edge of the blade.

[0016] Preferably, the groove is in an arc shape that is recessed from the trailing edge of the blade toward the leading edge.

[0017] Furthermore, the grooves have at least two arranged along the axial direction, and the radii of at least two grooves are different, thereby making the reaction time of the incoming flow vortex at different positions inconsistent, weakening the response of the blade to the incoming flow turbulence, thereby reducing the pressure pulsation on the blade surface and reducing the aerodynamic noise.

[0018] The technical solution adopted by the utility model to solve the second technical problem is: a fan, characterized in that: an impeller as described above is applied.

[0019] The technical solution adopted by the utility model to solve the third technical problem is: a range hood, characterized in that: the fan as described above is applied.

[0020] Compared with the prior art, the utility model has the following advantages: by opening a hole near the top of the blade, a pressure difference is formed on both sides of the blade, generating a stream vortex, which draws in the mainstream and interacts with the wake shear layer to break up the large-scale vortex structure in the wake, and the vortex shedding at the top of the blade is reduced, so that a higher total pressure than the prototype fan can be obtained, and the utility model has better aerodynamic performance; by using the first serration and the second serration arranged at the root of the first serration, the fluid flow velocity is accelerated, the energy of the separation vortex can be better weakened, the large-scale vortex is gradually broken into small-scale vortices, and the vortex system structure is more compact; grooves with different radii are arranged on the trailing edge of the blade, so that the reaction time of the incoming flow vortex at different positions is inconsistent, the response of the blade to the incoming flow turbulence is weakened, thereby reducing the pressure pulsation on the blade surface and reducing the aerodynamic noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of a range hood according to an embodiment of the utility model;

[0022] Figure 2 It is a schematic diagram of an impeller with a hidden front disc according to an embodiment of the utility model;

[0023] Figure 3 A schematic diagram of the blades of the impeller of an embodiment of the utility model;

[0024] Figure 4 for Figure 3 A schematic diagram of the partial enlargement of Ⅰ;

[0025] Figure 5 for Figure 3 A partial II enlarged schematic diagram of

[0026] Figure 6 This is a surface acoustic power simulation diagram of the impeller of the utility model;

[0027] Figure 7 is the vortex diagram of the impeller of the utility model;

[0028] Figure 8 This is a surface acoustic power simulation diagram of the impeller of the utility model (the bottom of the impeller);

[0029] Fig. 9 It is a surface acoustic power simulation diagram of an impeller in the prior art;

[0030] Fig.10 This is a surface acoustic power simulation diagram of an impeller in the prior art (bottom of the impeller). DETAILED DESCRIPTION

[0031] Embodiments of the present utility model are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions.

[0032] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Since the embodiments disclosed in the present utility model can be set in different directions, these terms indicating directions are only for illustration and should not be regarded as limitations. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features.

[0033] See also Figure 1 to Figure 5 A range hood includes a housing 1 and a fan 2 disposed in the housing 1. The fan 2 is a centrifugal fan, including a volute 21, an impeller 22 disposed in the volute 21, and a motor (not shown) for driving the impeller 22. The impeller 22 includes a front disc 221, a rear disc 222, and a plurality of blades 223 disposed between the front disc 221 and the rear disc 222. When the fan 2 is a single air inlet, the front disc 221 is located at the air inlet side. When the fan 2 is a double air inlet, the front disc 221 is located at the main air inlet side. The above structure is a prior art and will not be described in detail here.

[0034] The blade 223 has a leading edge and a trailing edge, the leading edge is the air inlet side of the blade 223, and the trailing edge is the air outlet side of the blade 223. A hole 224 is provided on the blade 223 near the top of the blade (the end where the blade 223 is connected to the front disk 221). Under the condition of small flow, the setting of the hole 224 can obtain a higher total pressure than the prototype fan, and has better aerodynamic performance. The number of holes 224 is at least two, and they are arranged at intervals between the leading edge and the trailing edge of the blade 223. Preferably, the hole 224 is elliptical, the long axis of the ellipse extends between the leading edge and the trailing edge of the blade 223, and the short axis of the ellipse extends in the axial direction (the blade height direction) of the impeller 22. As a result, the elliptical hole 224 suppresses the development of the vortex along the normal direction of the surface of the blade 221, and accelerates the energy attenuation of the trailing edge vortex along the flow direction. At the same time, the jet of the elliptical hole 224 breaks the large vortex into small vortices, so that the aerodynamic noise is reduced.

[0035] The hole 224 reduces the vortex shedding at the top of the blade and the vortex shedding position is closer to the top of the blade. In this case, the position between the hole 224 and the top of the blade on the blade 221 is used, and the first sawtooth 225 and the second sawtooth 226 are formed on the leading edge, wherein the size of the first sawtooth 225 is larger than the second sawtooth 226, which is more conducive to vortex breaking, and the second sawtooth 226 is located at the root of the first sawtooth 225. The first sawtooth 225 and the second sawtooth 226 are triangular sawtooths.

[0036] In addition, the pressure difference on both sides of the blade formed by the hole 224 generates a stream vortex, which draws the mainstream in and interacts with the wake shear layer to break up the large-scale vortex structure in the wake. The broken small vortices gather at the top of the blade, and the second sawtooth 226 in the first sawtooth 225 accelerates the fluid flow speed, which can better weaken the energy of the separation vortex, and the large-scale vortex is gradually broken into small-scale vortices, and the vortex system structure is more compact.

[0037] See also Figure 6 and Fig. 9 By using the hole 224, the first sawtooth 225 and the second sawtooth 226, the acoustic power on the impeller surface is reduced from 99.4db in the prior art to 95.4db. Figure 6 ,It can be seen from the vorticity diagram that the impeller of the ,utility invention has fewer and more dispersed large-scale vortices at the top and the bottom of the impeller, indicating that most of

[0038] The trailing edge of the blade 223 is formed with at least two axially arranged grooves 227 near the bottom of the blade (the end where the blade 223 is connected to the rear disk 222). The grooves 227 are in the shape of an arc that is recessed from the trailing edge to the leading edge of the blade 223. The radii of at least two grooves 227 are different, so that the reaction time of the incoming flow vortex at different positions is inconsistent, which weakens the response of the blade to the incoming flow turbulence, thereby reducing the pressure pulsation on the blade surface and reducing the aerodynamic noise.

[0039] See also Fig.10 , the existing impeller bottom surface acoustic power is large, and the blade surface pressure pulsation is large. Figure 8 By setting the above groove 227, the surface acoustic power at the trailing edge of the bottom of the impeller of the utility model is relatively small, indicating that the arc feature weakens the influence of the incoming flow turbulence and reduces the pressure pulsation on the blade surface.

Claims

1. An impeller, comprising a front disk (221), a rear disk (222), and a blade (223) arranged between the front disk (221) and the rear disk (222), wherein the top of the blade (223) is fixed to the front disk (221), the bottom of the blade (223) is fixed to the rear disk (222), and the blade (223) has a leading edge and a trailing edge; characterized in that: A hole (224) is provided on the blade (223) at a position close to the top of the blade. There are at least two holes (224) which are arranged at intervals between the leading edge and the trailing edge of the blade (223).

2. The impeller according to claim 1, characterized in that: The hole (224) is elliptical in shape, with the major axis of the ellipse extending between the leading edge and the trailing edge of the blade (223), and the minor axis of the ellipse extending in the axial direction of the impeller.

3. The impeller according to claim 1, characterized in that: A first sawtooth (225) is formed on the leading edge of the blade (223), and the first sawtooth (225) is located between the hole (224) and the top of the blade (223).

4. The impeller according to claim 3, characterized in that: A second saw tooth (226) is provided at the root of the first saw tooth (225), and the size of the first saw tooth (225) is larger than that of the second saw tooth (226).

5. The impeller according to claim 4, characterized in that: The first saw teeth (225) and the second saw teeth (226) are both triangular saw teeth.

6. The impeller according to claim 1, characterized in that: A groove (227) is formed on the trailing edge of the blade (223) near the bottom of the blade.

7. The impeller according to claim 6, characterized in that: The groove (227) is in the shape of an arc that is recessed from the trailing edge to the leading edge of the blade (223).

8. The impeller according to claim 7, characterized in that: The grooves (227) have at least two grooves arranged along the axial direction, and the radii of at least the two grooves (227) are different.

9. A fan, characterized in that: The impeller according to any one of claims 1 to 8 is used.

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

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