A centrifugal fan impeller, a centrifugal fan and a sanitation vehicle

Abstract

The present application discloses a centrifugal fan impeller, the blade profile of the blade of the centrifugal fan impeller includes three arcs that are tangentially connected in sequence from the impeller inlet to the impeller outlet. The first arc is connected to the second arc in an inward transition, and the second arc is connected to the third arc in an outward transition. The relationship between the radius R1 of the first arc and the radius R2 of the second arc is: 5.4R1<R2<5.8R1; the relationship between the radius R1 of the first arc and the radius R3 of the third arc is: 1.8R1<R3<2.2R1; the range of the inlet angle is 23°~30°, and the outlet angle is 87°~93°. This solution uses three arcs with better transition to construct the blade profile, ensuring a larger impeller outlet angle and a suitable inlet angle, and the blade inlet and outlet form a smooth transition, which advantageously ensures the smoothness of the airflow channel, thereby achieving the purpose of reducing noise and increasing efficiency. The present application also discloses a centrifugal fan and a sanitation vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of fans, and in particular to a centrifugal fan impeller, a centrifugal fan and a sanitation vehicle. Background Art

[0002] Sanitation vehicles for cleaning operations include road sweepers, washers, and vacuum trucks. These specialized vehicles rely on high-pressure centrifugal fans to create negative pressure, sucking debris from the ground into a trash container for effective cleaning. Currently, specialized centrifugal fans in use in the industry face challenges such as low efficiency and high noise levels. With the increasing adoption of electric vehicles, more and more companies are investing heavily in the development of all-electric sanitation vehicles. Due to current limitations such as battery capacity, the operating time per charge is a key competitive technical indicator. Longer operating times indicate higher efficiency, while lower operating times indicate lower efficiency. Improving overall efficiency is a key focus of sanitation vehicle technology research and development. Due to their electric motor drive, sanitation vehicles' chassis and other components generate very low operating noise, with the primary source of noise coming from the centrifugal fans. Sanitation vehicles are most commonly used on urban arterial roads, operating in the early morning hours when traffic is light and most residents are resting. Therefore, noise nuisance is a key consideration for sanitation vehicle purchasers. Therefore, reducing noise and increasing efficiency of centrifugal fans in sanitation vehicles is crucial for enhancing their overall competitiveness.

[0003] Centrifugal fans are a type of fan with a history of over a hundred years. A lot of work has been done by our predecessors to improve their efficiency. However, the centrifugal fans currently used in sanitation vehicles still generally have low operating efficiency. Some have an efficiency of less than 60%, and the aerodynamic efficiency of centrifugal fans in most complete vehicle products does not exceed 75%.

[0004] In the prior art, there are centrifugal fans with different blade shapes, such as backward centrifugal fans, forward centrifugal fans, and straight-blade centrifugal fans.

[0005] Traditional forward-facing centrifugal fans feature a linear and arc-shaped impeller profile, with a straight line at the inlet and a combination of an arc and straight line at the outlet. While forward-facing centrifugal fans can provide high pressure, their inherent drawbacks (large outlet angles and the tendency for flow separation at the impeller outlet) result in low efficiency and high noise. While these fans were widely used in sanitation vehicles during their early stages of development, they have since been replaced by other types.

[0006] Existing backward-facing centrifugal fans typically utilize a single arc from the impeller inlet to the outlet, with blades designed at varying inlet and outlet angles. Overall, this type of blade shape offers improved efficiency compared to forward-facing centrifugal fans, reaching approximately 80% aerodynamic efficiency. However, the fan pressure provided is relatively low, often failing to reach its peak efficiency when used on sanitation vehicles. This results in the fan itself being highly efficient but operating inefficiently.

[0007] Therefore, how to solve the problem of low efficiency and high noise of existing centrifugal fans is a technical problem that those skilled in the art currently need to solve. Summary of the Invention

[0008] In view of this, an object of the present invention is to provide a centrifugal fan impeller having the effect of reducing noise and increasing efficiency. Another object of the present invention is to provide a centrifugal fan including the centrifugal fan impeller and a sanitation vehicle including the centrifugal fan.

[0009] In order to achieve the above object, the present invention provides the following technical solutions:

[0010] A centrifugal fan impeller includes a front disk, blades and a rear disk, the blade profile of the blades including a first arc, a second arc and a third arc that are tangentially connected in sequence from the impeller inlet to the impeller outlet, the first arc is inscribed in the second arc and transitionally connected, the second arc is inscribed in the third arc and transitionally connected, the relationship between the radius R1 of the first arc and the radius R2 of the second arc is: 5.4R1<R2<5.8R1; the relationship between the radius R1 of the first arc and the radius R3 of the third arc is: 1.8R1<R3<2.2R1; the inlet angle of the impeller inlet ranges from 23° to 30°, and the outlet angle of the impeller outlet ranges from 87° to 93°.

[0011] Preferably, the relationship between the radius R1 of the first arc and the radius R2 of the second arc is: R2=5.572R1, and the relationship between the radius R1 of the first arc and the radius R3 of the third arc is: R3=1.985R1; the inlet angle of the impeller inlet is 27°, and the outlet angle of the impeller outlet is 90°.

[0012] Optionally, the relationship between the diameter D1 of the impeller inlet and the radius R3 of the third arc is: 0.90R3 <D1<0.96R3。

[0013] Preferably, the relationship between the diameter D1 of the impeller inlet and the radius R3 of the third arc is: D1 = 0.933R3.

[0014] Optionally, the relationship between the diameter D2 of the impeller outlet and the radius R2 of the second arc is: 0.95R2<D2<1.05R2.

[0015] Preferably, the relationship between the diameter D2 of the impeller outlet and the radius R2 of the second arc is: D2 = 0.99R2.

[0016] Optionally, the front disk is provided with a fan inlet, and the relationship between the diameter d of the fan inlet and the radius R1 of the first arc is: 2.8R1<d<3R1.

[0017] Preferably, the relationship between the diameter d of the fan inlet and the radius R1 of the first arc is: d=2.818R1.

[0018] The centrifugal fan impeller provided by the present invention includes a front disk, blades and a rear disk. The blade profile of the blade includes a first arc, a second arc and a third arc that are tangentially connected in sequence from the impeller inlet to the impeller outlet. The first arc is inscribed in the second arc and transitionally connected, and the second arc is inscribed in the third arc and transitionally connected. The relationship between the radius R1 of the first arc and the radius R2 of the second arc is: 5.4R1<R2<5.8R1; the relationship between the radius R1 of the first arc and the radius R3 of the third arc is: 1.8R1<R3<2.2R1; the inlet angle of the impeller inlet ranges from 23° to 30°, and the outlet angle of the impeller outlet ranges from 87° to 93°.

[0019] This solution uses three arc segments with better transitions to construct the blade profile, which not only ensures a larger impeller outlet angle but also a suitable inlet angle. The blade inlet and outlet form a smooth transition, which advantageously ensures the smoothness of the airflow channel, thereby achieving the purpose of noise reduction and efficiency improvement. This solution enables the centrifugal fan to achieve an efficiency of over 89% at the highest efficiency point under the same speed conditions, which is a significant improvement over the efficiency of the existing more efficient backward-facing centrifugal fans (up to 82%). The noise is reduced by about 2dB under the same flow and pressure conditions, which has a significant noise reduction and efficiency improvement effect. Under the same flow conditions, the fan pressure can be increased by more than 10%, which can form an optimal match with the pneumatic pipeline of the road sweeper.

[0020] The present invention further provides a centrifugal fan including the centrifugal fan impeller. The derivation process of the beneficial effects produced by the centrifugal fan is substantially similar to the derivation process of the beneficial effects produced by the centrifugal fan impeller, and thus will not be repeated herein.

[0021] The present invention further provides a sanitation vehicle including the centrifugal fan. The derivation process of the beneficial effects of the sanitation vehicle is generally similar to the derivation process of the beneficial effects brought about by the centrifugal fan, so it will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 Schematic diagram of the structure of a centrifugal fan impeller in a specific embodiment of the present invention;

[0024] Figure 2 Schematic diagram of the blade profile structure of a centrifugal fan impeller in a specific embodiment of the present invention;

[0025] Figure 3 It is a cross-sectional streamline view of the impeller flow channel of the centrifugal fan impeller in a specific embodiment of the present invention.

[0026] Figures 1 to 3 middle:

[0027] 1-Front disc, 2-Blades, 3-Rear disc, 4-Impeller inlet, 5-Impeller outlet, 6-Fan inlet. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] Please refer to Figures 1 to 3 , Figure 1 Schematic diagram of the structure of a centrifugal fan impeller in a specific embodiment of the present invention; Figure 2 Schematic diagram of the blade profile structure of a centrifugal fan impeller in a specific embodiment of the present invention; Figure 3 It is a cross-sectional streamline view of the impeller flow channel of the centrifugal fan impeller in a specific embodiment of the present invention.

[0030] The present invention provides a centrifugal fan impeller, such as Figure 1 As shown, the centrifugal fan impeller includes a front disc 1, blades 2 and a rear disc 3. Figure 2As shown, the blade profile of the blade 2 includes a first arc, a second arc and a third arc that are sequentially tangentially connected from the impeller inlet 4 to the impeller outlet 5. The first arc is inscribed in the second arc and transitionally connected, and the second arc is inscribed in the third arc and transitionally connected. The relationship between the radius R1 of the first arc and the radius R2 of the second arc is: 5.4R1<R2<5.8R1; the relationship between the radius R1 of the first arc and the radius R3 of the third arc is: 1.8R1<R3<2.2R1; the inlet angle of the impeller inlet 4 ( Figure 2 The range of the middle angle α) is 23°~30°, and the outlet angle of the impeller outlet 5 ( Figure 2 The median angle β) is 87°~93°.

[0031] Further preferably, the relationship between the radius R1 of the first arc and the radius R2 of the second arc is: R2 = 5.572R1, and the relationship between the radius R1 of the first arc and the radius R3 of the third arc is: R3 = 1.985R1; the inlet angle α of the impeller inlet 4 is 27°, and the outlet angle β of the impeller outlet 5 is 90°. These preferred values ​​can ensure the highest fan operating efficiency (above 89%).

[0032] Optionally, the relationship between the diameter D1 of the impeller inlet 4 and the radius R3 of the third arc is: 0.90R3 <D1<0.96R3。

[0033] Preferably, the relationship between the diameter D1 of the impeller inlet 4 and the radius R3 of the third arc is: D1 = 0.933R3.

[0034] Optionally, the relationship between the diameter D2 of the impeller outlet 5 and the radius R2 of the second arc is: 0.95R2<D2<1.05R2.

[0035] Preferably, the relationship between the diameter D2 of the impeller outlet 5 and the radius R2 of the second arc is: D2 = 0.99R2.

[0036] Optionally, the front disk 1 is provided with a fan inlet 6 , and the relationship between the diameter d of the fan inlet 6 and the radius R1 of the first arc is: 2.8R1<d<3R1.

[0037] Preferably, the relationship between the diameter d of the fan inlet 6 and the radius R1 of the first arc is: d=2.818R1.

[0038] It should be noted that fan impellers with different impeller outlet diameters D2 designed using the fan similarity principle all fall within the protection scope of this solution, that is, centrifugal fan impellers of different actual sizes that meet the dimensional constraints described above all fall within the protection scope of this solution.

[0039] It should be noted that the size of the impeller outlet angle is closely related to the fan pressure. The larger the outlet angle β is within a reasonable range, the higher the fan pressure is. The smaller the outlet angle is, the lower the pressure the fan can provide under the same speed conditions. The inlet angle α of the impeller inlet is closely related to the inlet noise and fan rotational stall. A too small inlet angle will result in a too small impeller inlet area, which is prone to rotational stall and emits a harsh and sharp noise. At the same time, the fan flow will be seriously insufficient. An excessively large inlet angle will cause secondary flow at the impeller inlet, which also leads to increased noise and decreased aerodynamic efficiency. This solution uses three arcs with better transition to construct the blade profile, which not only ensures a larger impeller outlet angle (87° to 93°) but also ensures a suitable impeller inlet angle (23° to 30°). The blade inlet and outlet form a smooth transition, which effectively ensures the smoothness of the airflow channel, thereby achieving the purpose of reducing noise and increasing efficiency.

[0040] Please refer to Figure 3 It can be seen from the CFD simulation analysis that the airflow in the impeller flow channel of this solution is very smooth, there is no obvious vortex, and there is no obvious vortex or secondary flow at the impeller outlet. The flow efficiency is high, which effectively improves the operating efficiency of the fan and reduces the aerodynamic noise of the fan. According to CFD analysis, this solution enables the centrifugal fan to achieve a maximum efficiency point efficiency of more than 89% under the same speed conditions, which is a significant improvement compared to the existing high-efficiency backward centrifugal fan efficiency (up to 82%); under the same flow and pressure conditions, the noise is reduced by about 2dB, which has a significant noise reduction and efficiency improvement effect. Under the same flow conditions, the fan pressure can be increased by more than 10%, which can form an optimal match with the pneumatic pipeline of the road sweeper.

[0041] The present invention further provides a centrifugal fan including the centrifugal fan impeller. The derivation process of the beneficial effects produced by the centrifugal fan is substantially similar to the derivation process of the beneficial effects produced by the centrifugal fan impeller, and thus will not be repeated herein.

[0042] The present invention further provides a sanitation vehicle including the centrifugal fan. The derivation process of the beneficial effects of the sanitation vehicle is generally similar to the derivation process of the beneficial effects brought about by the centrifugal fan, so it will not be repeated here.

[0043] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A centrifugal fan impeller, comprising a front disc (1), blades (2) and a rear disc (3), characterized in that: The blade profile of the blade (2) includes a first arc, a second arc, and a third arc that are tangentially connected in sequence from the impeller inlet (4) to the impeller outlet (5). The first arc is connected to the second arc by an internal tangent transition, and the second arc is connected to the third arc by an external tangent transition. The relationship between the radius R1 of the first arc and the radius R2 of the second arc is: 5.4R1 < R2 < 5.8R1; the relationship between the radius R1 of the first arc and the radius R3 of the third arc is: 1.8R1 < R3 < 2.2R1; the range of the inlet angle of the impeller inlet (4) is 23° - 30°, and the outlet angle of the impeller outlet (5) is 87° - 93°; The relationship between the diameter D1 of the impeller inlet (4) and the radius R3 of the third arc is: 0.90R3 < D1 < 0.96R3; the relationship between the diameter D2 of the impeller outlet (5) and the radius R2 of the second arc is: 0.95R2 < D2 < 1.05R2; The front disc is provided with a fan inlet (6). The relationship between the diameter d of the fan inlet (6) and the radius R1 of the first arc is: 2.8R1 < d < 3R1.

2. The centrifugal fan impeller according to claim 1, characterized in that: The relationship between the radius R1 of the first arc and the radius R2 of the second arc is: R2 = 5.572R1, and the relationship between the radius R1 of the first arc and the radius R3 of the third arc is: R3 = 1.985R1; the inlet angle of the impeller inlet (4) is 27°, and the outlet angle of the impeller outlet (5) is 90°.

3. The centrifugal fan impeller according to claim 1, characterized in that: The relationship between the diameter D1 of the impeller inlet (4) and the radius R3 of the third arc is: D1 = 0.933R3.

4. The centrifugal fan impeller according to claim 1, characterized in that: The relationship between the diameter D2 of the impeller outlet (5) and the radius R2 of the second arc is: D2 = 0.99R2.

5. The centrifugal fan impeller according to claim 1, characterized in that: The relationship between the diameter d of the fan inlet (6) and the radius R1 of the first arc is: d = 2.818R1.

6. A centrifugal fan, characterized in that: It includes the centrifugal fan impeller according to any one of claims 1 to 5.

7. A sanitation vehicle, characterized in that: It includes the centrifugal fan according to claim 6.

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