Centrifugal impeller, centrifugal fan, air conditioner and household appliance

Abstract

The present invention provides a centrifugal impeller, a centrifugal fan, an air conditioner and a household appliance. The centrifugal impeller includes a hub and at least two blade groups. The multiple blade groups are evenly distributed in the circumferential direction of the hub on an axial end face of the hub. Each blade group includes a first blade and a second blade. A first air inlet end of the first blade protrudes axially of the hub from a second air inlet end of the second blade. The first air inlet end is the end of the first blade away from the hub in the axial direction of the hub, and the second air inlet end is the end of the second blade away from the hub in the axial direction of the hub. The centrifugal impeller of the present invention can make the flow field in the volute more uniform, thereby effectively reducing the rotational noise and the jet noise, and effectively improving the surge problem of the centrifugal fan.

Description

Technical Field

[0001] The present invention relates to the technical field of centrifugal fans, and in particular to a centrifugal impeller of a centrifugal fan, a centrifugal fan having the centrifugal impeller, an air conditioner having the centrifugal fan, and a household appliance having the centrifugal fan. Background Art

[0002] A centrifugal fan is a machine that relies on the input mechanical energy to pressurize the air flow from the axial inlet and discharge it radially, thereby increasing the gas pressure and discharging the gas. Centrifugal fans are widely used in ventilation, dust removal, and cooling in factories, mines, tunnels, cooling towers, vehicles, ships, and buildings; ventilation and induced draft in boilers and industrial furnaces; cooling and ventilation in air conditioning equipment and household electrical appliances; drying and selection of grains; air sources in wind tunnels and inflation and propulsion of hovercrafts, etc.

[0003] The main structure of a centrifugal fan includes an impeller, a volute, a collector, etc. The impeller, as the core component of the centrifugal fan, is driven by a prime mover to rotate. When the impeller rotates, it transfers the mechanical energy of the prime mover to the gas, causing the gas pressure to increase.

[0004] See Figure 1 , in the existing centrifugal impeller 1, a plurality of blades 12 are evenly distributed on the hub 11 of the centrifugal impeller 1 in the circumferential direction of the centrifugal impeller 1, and the air inlet ends 13 of the plurality of blades 12 away from the hub 11 in the axial direction of the centrifugal impeller 1 are flush with each other, that is, the heights of the plurality of blades 12 in the axial direction of the centrifugal impeller 1 are equal. During the process of the prime mover driving the centrifugal impeller 1 to drive the blades 12 to rotate, the air inlet ends 13 of the blades 12 rotate and disturb the axial air flow entering the volute. Since the air inlet ends 13 of the plurality of blades 12 of the existing centrifugal impeller 1 are flush with each other, the disturbance to the air flow axially entering the volute is not uniform enough, especially the air flow distribution in the axial direction of the volute is more uneven, resulting in an uneven flow field in the volute, and thus causing the generation of rotational noise and jet noise. Among them, the rotational noise belongs to a dipole source and is discrete frequency noise. In addition to the uneven air flow in the vortex shedding area, the noise is also generated by the pressure pulsation of the air caused by the blades 12 hitting the air, while the jet noise is the noise generated when the air flow in the volute is ejected from the outlet of the volute at a high speed. Summary of the Invention

[0005] The first object of the present invention is to provide a centrifugal impeller that can make the flow field in the volute more uniform, thereby effectively reducing the rotational noise and jet noise, and effectively improving the surge problem of the centrifugal fan.

[0006] The second object of the present invention is to provide a centrifugal fan having the above centrifugal impeller.

[0007] The third object of the present invention is to provide an air conditioner having the above centrifugal fan.

[0008] The fourth object of the present invention is to provide a household appliance having the above centrifugal fan.

[0009] In order to achieve the first object of the present invention, the present invention provides a centrifugal impeller, including a hub and at least two blade groups. The multiple blade groups are evenly distributed in the circumferential direction of the hub on an axial end surface of the hub. Each blade group includes a first blade and a second blade. The first air inlet end of the first blade protrudes from the second air inlet end of the second blade in the axial direction of the hub. The first air inlet end is the end of the first blade away from the hub in the axial direction of the hub, and the second air inlet end is the end of the second blade away from the hub in the axial direction of the hub.

[0010] As can be seen from the above solution, there is a height difference in the axial direction of the hub between the first air inlet end of the first blade and the second air inlet end of the second blade of the centrifugal impeller of the present invention, which can effectively improve the uniformity of the air flow distribution in the axial direction of the volute, make the flow field in the volute more uniform, thereby effectively reducing the rotational noise. At the same time, the non-uniformity in the axial direction of the hub between the first air inlet end of the first blade and the second air inlet end of the second blade causes the jet noise sound wave to be reflected on the rotating blade, thereby effectively reducing the jet noise, and can reduce the air flow pulsation degree in the volute, effectively improving the surge problem of the centrifugal fan.

[0011] A preferred solution is that each blade group further includes a third blade, and the second air inlet end protrudes from the third air inlet end of the third blade in the axial direction of the hub. The third air inlet end is the end of the third blade away from the hub in the axial direction of the hub.

[0012] A further solution is that the first height difference between the first air inlet end and the second air inlet end in the axial direction of the hub is less than 25% - 35% of the height of the first blade in the axial direction of the hub; and / or, the second height difference between the second air inlet end and the third air inlet end in the axial direction of the hub is less than 25% - 35% of the height of the first blade in the axial direction of the hub.

[0013] A further solution is that the first height difference and the second height difference are equal.

[0014] A further solution is that the outer peripheral diameter of the hub is 130 mm - 150 mm.

[0015] A further solution is that the wrap angle of the first blade is 2° - 8°; and / or, the wrap angle of the second blade is 2° - 8°; and / or, the wrap angle of the third blade is 2° - 8°.

[0016] A further solution is that the inlet angle of the first blade is between 40° and 60°; and / or, the inlet angle of the second blade is between 40° and 60°; and / or, the inlet angle of the third blade is between 40° and 60°.

[0017] In a further embodiment, the outlet angle of the first blade is 20° to 50°; and / or, the outlet angle of the second blade is 20° to 50°; and / or, the outlet angle of the third blade is 20° to 50°.

[0018] In an even further embodiment, the first inlet diameter of the first blade is smaller than the second inlet diameter of the second blade, and the second inlet diameter is smaller than the third inlet diameter of the third blade.

[0019] In an even further embodiment, the first difference between the first inlet diameter and the second inlet diameter is equal to the second difference between the second inlet diameter and the third inlet diameter.

[0020] In an even further embodiment, the first inlet diameter is 0.63 times the outer peripheral diameter of the hub; and / or, the second inlet diameter is 0.7 times the outer peripheral diameter of the hub; and / or, the third inlet diameter is 0.77 times the outer peripheral diameter of the hub.

[0021] To achieve the second object of the present invention, the present invention provides a centrifugal fan, including a centrifugal impeller, and the centrifugal impeller is the above-mentioned centrifugal impeller.

[0022] To achieve the third object of the present invention, the present invention provides an air conditioner, including a centrifugal fan, and the centrifugal fan is the above-mentioned centrifugal fan.

[0023] To achieve the fourth object of the present invention, the present invention provides a household appliance, including a centrifugal fan, and the centrifugal fan is the above-mentioned centrifugal fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a structural diagram of an existing centrifugal impeller.

[0025] Figure 2 is a radial sectional view of an embodiment of the centrifugal fan of the present invention.

[0026] Figure 3 is a side view of an embodiment of the centrifugal fan of the present invention.

[0027] Figure 4 is an axial sectional view of an embodiment of the centrifugal fan of the present invention.

[0028] Figure 5 is an exploded view of the structure of an embodiment of the centrifugal fan of the present invention.

[0029] Figure 6 is a structural diagram of the centrifugal impeller in an embodiment of the centrifugal fan of the present invention.

[0030] Figure 7 is a schematic diagram of the blade group of the centrifugal impeller in an embodiment of the centrifugal fan of the present invention

[0031] Figure 8 This is the front view of the centrifugal impeller in the centrifugal fan embodiment of the present invention.

[0032] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. Specific embodiments

[0033] See Figures 2 to 8 , in this centrifugal fan embodiment, it includes a motor (not labeled), a volute 21, an air inlet collector (not labeled), and a centrifugal impeller 25. The volute 21 is a hollow annular housing. A volute tongue 22 is convexly provided on the outer circumferential side wall of the volute 21. A square air outlet 24 communicating with the hollow inner cavity 23 of the volute 21 is provided at one end of the volute tongue 22 away from the volute 21. A circular air inlet 26 communicating with the hollow inner cavity 23 of the volute 21 is penetrated and opened on the first axial end face of the volute 21. The centrifugal impeller 25 is eccentrically arranged in the hollow inner cavity 23 of the volute 21. The motor is arranged on the second axial end face of the volute 21, and the drive shaft of the motor is axially connected to the hub 251 of the centrifugal impeller 25 to drive the centrifugal impeller 25 to rotate. The air inlet collector is arranged on the first axial end face of the volute 21 and corresponds to the air inlet 26. The air inlet collector is an annular structure for guiding external air flow through the air inlet 26 axially into the hollow inner cavity 23 of the volute 21, and then discharging from the air outlet 24 of the volute tongue 22 under the rotational disturbance of the centrifugal impeller 25.

[0034] In this embodiment, the centrifugal impeller 25 includes a hub 251 and at least two blade groups 252. The multiple blade groups 252 are evenly distributed in the circumferential direction of the hub 251 on an axial end face of the hub 251. Each blade group 252 includes a first blade 2521 and a second blade 2522. The first air inlet end 25211 of the first blade 2521 protrudes axially from the second air inlet end 25221 of the second blade 2522. The first air inlet end 25211 of the first blade 2521 is the end of the first blade 2521 that is axially away from the hub 251 relative to the hub 251, and the second air inlet end 25221 of the second blade 2522 is the end of the second blade 2522 that is axially away from the hub 251 relative to the hub 251. That is, the first air inlet end 25211 of the first blade 2521 is the end of the first blade 2521 that is axially closer to the air inlet 26 of the volute 21 relative to the hub 251, and the second air inlet end 25221 of the second blade 2522 is the end of the second blade 2522 that is axially closer to the air inlet 26 of the volute 21 relative to the hub 251. There is a height difference in the axial direction of the hub 251 between the first air inlet end 25211 of the first blade 2521 and the second air inlet end 25221 of the second blade 2522 of the centrifugal impeller 25 in this embodiment, which can effectively improve the uniformity of the air flow distribution in the axial direction of the volute 21, make the flow field in the volute 21 more uniform, thereby effectively reducing the rotational noise. At the same time, the non-uniformity in the axial direction of the hub 251 between the first air inlet end 25211 of the first blade 2521 and the second air inlet end 25221 of the second blade 2522 causes the jet noise sound wave to be reflected on the rotating blade, thereby effectively reducing the jet noise, and can reduce the pulsation degree of the air flow in the volute 21 and effectively improve the surging problem of the centrifugal fan.

[0035] In order to further reduce the rotational noise and jet noise and improve the surge problem of the centrifugal fan, each blade group 252 in this embodiment further includes a third blade 2523. The second air inlet end 25221 protrudes axially of the hub 251 and is arranged at the third air inlet end 25231 of the third blade 2523. The third air inlet end 25231 of the third blade 2523 is the end of the third blade 2523 that is axially away from the hub 251 in the hub 251, that is, the third air inlet end 25231 of the third blade 2523 is the end of the third blade 2523 that is axially close to the air inlet 26 of the volute 21 in the hub 251. As a result, the third air inlet end 25231 of the third blade 2523, the second air inlet end 25221 of the second blade 2522, and the first air inlet end 25211 of the first blade 2521 are unevenly distributed in a rising step shape axially of the hub 251. Among them, the first height difference H4 axially of the hub 251 between the first air inlet end 25211 of the first blade 2521 and the second air inlet end 25221 of the second blade 2522 is less than 25% - 35% of the height H1 of the first blade 2521 axially of the hub 251, and the second height difference H5 axially of the hub 251 between the second air inlet end 25221 of the second blade 2522 and the third air inlet end 25231 of the third blade 2523 is less than 25% - 35% of the height H1 of the first blade 2521 axially of the hub 251, thereby ensuring the structural strength of the first blade 2521, the second blade 2522, and the third blade 2523. Specifically, in this embodiment, the first height difference H4 axially of the hub 251 between the first air inlet end 25211 of the first blade 2521 and the second air inlet end 25221 of the second blade 2522 is less than 30% of the height H1 of the first blade 2521 axially of the hub 251, and the second height difference H5 axially of the hub 251 between the second air inlet end 25221 of the second blade 2522 and the third air inlet end 25231 of the third blade 2523 is less than 30% of the height H1 of the first blade 2521 axially of the hub 251. Preferably, the first height difference H4 and the second height difference H5 are equal, that is, both the first height difference H4 and the second height difference H5 are 5 mm. Specifically, in this embodiment, the height H1 of the first blade 2521 axially of the hub 251 is 40 mm, the height H2 of the second blade 2522 axially of the hub 251 is 35 mm, and the height H3 of the third blade 2523 axially of the hub 251 is 30 mm.

[0036] In this embodiment, the first inlet diameter D1 of the first blade 2521 is smaller than the second inlet diameter D2 of the second blade 2522, and the second inlet diameter D2 of the second blade 2522 is smaller than the third inlet diameter D3 of the third blade 2523. The first inlet diameter D1 of the first blade 2521 is the diameter of the first ring 253 formed between the first air inlet edges of multiple first blades 2521 that are closer to the axis of the hub 251 in the radial direction of the hub 251. The second inlet diameter D2 of the second blade 2522 is the diameter of the second ring 254 formed between the second air inlet edges of multiple second blades 2522 that are closer to the axis of the hub 251 in the radial direction of the hub 251. The third inlet diameter D3 of the third blade 2523 is the diameter of the third ring 256 formed between the third air inlet edges of multiple third blades 2523 that are closer to the axis of the hub 251 in the radial direction of the hub 251. Since the first inlet diameter D1 of the first blade 2521 in this embodiment is smaller than the second inlet diameter D2 of the second blade 2522, and the second inlet diameter D2 of the second blade 2522 is smaller than the third inlet diameter D3 of the third blade 2523, the third air inlet edge of the third blade 2523, the second air inlet edge of the second blade 2522, and the first air inlet edge of the first blade 2521 are unevenly distributed in a rising step shape in the radial direction of the hub 251, thereby forming a two-stage supercharging effect, which can effectively increase the air volume of the centrifugal fan by 15% compared with the conventional centrifugal fan at the same rotational speed. If the air volume is the same, it can make the power of the centrifugal fan lower and more efficient.

[0037] Specifically, the first difference between the first inlet diameter D1 of the first blade 2521 and the second inlet diameter D2 of the second blade 2522 in this embodiment is equal to the second difference between the second inlet diameter D2 of the second blade 2522 and the third inlet diameter D3 of the third blade 2523. Preferably, the first inlet diameter D1 of the first blade 2521 is 0.63 times the outer peripheral diameter D of the hub 251, the second inlet diameter D2 of the second blade 2522 is 0.7 times the outer peripheral diameter D of the hub 251, and the third inlet diameter D3 of the third blade 2523 is 0.77 times the outer peripheral diameter D of the hub 251. Among them, the outer peripheral diameter D of the hub 251 in this embodiment is 130 mm to 150 mm. Preferably, the outer peripheral diameter D of the hub 251 in this embodiment is 140 mm. In addition, the wrap angle of the first blade 2521 in this embodiment is 2° to 8°, the wrap angle of the second blade 2522 is 2° to 8°, and the wrap angle of the third blade 2523 is 2° to 8°. Preferably, the wrap angle of the first blade 2521 in this embodiment is 4°, the wrap angle of the second blade 2522 is 4°, and the wrap angle of the third blade 2523 is 4°. The wrap angle θ of the blade is the angle passing through the axis of the hub 251 between the root of the blade radially away from the axis of the hub 251 and the tangent of the arc of the blade radially close to the axis of the hub 251. The inlet angle of the first blade 2521 in this embodiment is between 40° and 60°, the inlet angle of the second blade 2522 is between 40° and 60°, and the inlet angle of the third blade 2523 is between 40° and 60°. The inlet angle γ of the blade is the angle between the tangent of the arc of the blade radially close to the axis of the hub 251 and the plane passing through the axis of the hub 251 at the intersection point between the tangent and the arc of the blade. In addition, the outlet angle of the first blade 2521 in this embodiment is 20° to 50°, the outlet angle of the second blade 2522 is 20° to 50°, and the outlet angle of the third blade 2523 is 20° to 50°. Preferably, the outlet angle of the first blade 2521 in this embodiment is 30°, the outlet angle of the second blade 2522 is 30°, and the outlet angle of the third blade 2523 is 30°. The outlet angle β of the blade is the angle between the tangent of the arc of the blade radially away from the axis of the hub 251 and the outer peripheral tangent of the hub 251. Thus, the centrifugal impeller 25 in this embodiment can effectively improve the air flow distribution at the position of the hub 251, reduce the average pressure of the hub 251, and can disturb more air flow into the hollow inner cavity 23 of the volute 21, thereby increasing the air volume.

[0038] The centrifugal fan equipped with the centrifugal impeller 25 of the present invention can be applied to air conditioners and other household appliances. The household appliances also include electric fans, air purifiers, humidifiers, etc.

[0039] The above embodiments are only preferred examples of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, any equivalent changes or modifications made according to the structure, features, and principles of the scope of the patent application of the present invention should be included within the scope of the patent application of the present invention.

Claims

1. The centrifugal impeller includes a hub, and is characterized in that, It further includes at least two blade groups, and a plurality of the blade groups are evenly distributed in the circumferential direction of the hub on an axial end face of the hub; Each of the blade groups includes a first blade and a second blade, and a first air inlet end of the first blade protrudes from a second air inlet end of the second blade in the axial direction of the hub; The first air inlet end is the end of the first blade away from the hub in the axial direction of the hub, and the second air inlet end is the end of the second blade away from the hub in the axial direction of the hub; Each of the blade groups further includes a third blade, and the second air inlet end protrudes from a third air inlet end of the third blade in the axial direction of the hub, and the third air inlet end is the end of the third blade away from the hub in the axial direction of the hub; A first inlet diameter of the first blade is smaller than a second inlet diameter of the second blade, and the second inlet diameter is smaller than a third inlet diameter of the third blade; A first difference between the first inlet diameter and the second inlet diameter is equal to a second difference between the second inlet diameter and the third inlet diameter.

2. The centrifugal impeller according to claim 1, is characterized in that: A first height difference between the first air inlet end and the second air inlet end in the axial direction of the hub is less than 25% - 35% of the height of the first blade in the axial direction of the hub; and / or, a second height difference between the second air inlet end and the third air inlet end in the axial direction of the hub is less than 25% - 35% of the height of the first blade in the axial direction of the hub.

3. The centrifugal impeller according to claim 2, is characterized in that: The first height difference and the second height difference are equal.

4. The centrifugal impeller according to claim 1, is characterized in that: The outer peripheral diameter of the hub is 130 mm - 150 mm.

5. The centrifugal impeller according to claim 1, is characterized in that: The included angle of the first blade is 2° - 8°; and / or, the included angle of the second blade is 2° - 8°; and / or, the included angle of the third blade is 2° - 8°.

6. The centrifugal impeller according to claim 1, is characterized in that: The inlet angle of the first blade is between 40° and 60°; and / or, the inlet angle of the second blade is between 40° and 60°; and / or, the inlet angle of the third blade is between 40° and 60°.

7. The centrifugal impeller according to claim 1, is characterized in that: The outlet angle of the first blade is 20° - 50°; and / or, the outlet angle of the second blade is 20° - 50°; and / or, the outlet angle of the third blade is 20° - 50°.

8. The centrifugal impeller according to claim 1, is characterized in that: The first inlet diameter is 0.63 times the outer peripheral diameter of the hub; and / or, the second inlet diameter is 0.7 times the outer peripheral diameter of the hub; and / or, the third inlet diameter is 0.77 times the outer peripheral diameter of the hub.

9. The centrifugal fan includes a centrifugal impeller, and is characterized in that: The centrifugal impeller is the centrifugal impeller according to any one of claims 1 to 8 above.

10. The air conditioner includes a centrifugal fan, and is characterized in that: The centrifugal fan is the centrifugal fan according to claim 9 above.

11. The household appliance includes a centrifugal fan, and is characterized in that: The centrifugal fan is the centrifugal fan according to claim 9 above.

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