A centrifugal fan

Abstract

The application provides a centrifugal fan, comprising an impeller, wherein a blade one is arranged on the impeller, the blade one is a wing type blade, an outlet angle alpha of the blade one is 45-55 DEG, an inlet side of the blade one is an inclined structure, and an included angle beta between the inlet side and an axis is 8-10 DEG. The centrifugal fan further comprises a volute, the volute is a narrow volute structure, an axial dimension of the volute is 340-350 mm, and the width of the volute is 25-30% narrower than that of a conventional volute; the volute comprises a double-layer volute top plate and front and rear side plates oppositely arranged on both sides of the double-layer volute top plate; the double-layer volute top plate comprises an outer layer volute top plate and an inner layer volute top plate; and sound absorbing material is arranged between the outer layer volute top plate and the inner layer volute top plate. Through the above arrangement, the centrifugal fan meets the use requirements of large flow, high efficiency, low noise and compact space.

Description

Technical Field

[0001] This invention relates to the field of cooling systems for locomotives, and more specifically to a centrifugal fan. Background Technology

[0002] When a locomotive is in operation, it needs to use fans to cool its motors. One fan needs to cool three traction motors and one main generator at the same time. When the fans are used on the locomotive, they are limited by the space and layout of the locomotive. Therefore, these fans usually require large flow rate, high efficiency, low noise and compact space.

[0003] The existing locomotive converter cooling system fan design has problems such as low flow coefficient, high noise, limited axial dimension and low efficiency, which are difficult to meet the application requirements of locomotives. Specifically: (1) The noise of similar fans is greater than 109dB; (2) The efficiency of similar fans is usually between 65% and 70%, which is relatively low and the energy consumption is high during long-term operation; (3) When the flow rate of similar fans is 8.0m^3 / s, the fan pressure is difficult to reach 6000Pa; (4) The axial dimension is limited and the axial dimension of the fan exceeds the limit, making it difficult to meet the installation requirements.

[0004] In summary, there is an urgent need for a centrifugal fan with a large flow coefficient, high efficiency, low noise, and compact space to solve the problems existing in the current technology. Summary of the Invention

[0005] The purpose of this invention is to provide a centrifugal fan to solve the technical problems existing in the prior art. The specific technical solution is as follows: A centrifugal fan includes an impeller, the impeller includes a wheel body and a wheel core, and the wheel body and the wheel core are connected;

[0006] The wheel body includes a front wheel disc, a rear wheel disc, and multiple blades disposed between the front wheel disc and the rear wheel disc. The rear wheel disc is connected to the wheel core. The exit angle α of the blades is 45°-55°.

[0007] Furthermore, the first blade is an airfoil-type blade with an inclined structure on its inlet side, and the angle β between the inlet side and the axis is 8°-10°.

[0008] Furthermore, the number of blades is 12.

[0009] Furthermore, it also includes a volute, which includes a double-layer volute top plate and a front side plate and a rear side plate disposed opposite to each other on both sides of the double-layer volute top plate;

[0010] The double-layer volute top plate includes an outer volute top plate and an inner volute top plate; sound-absorbing material is provided between the outer volute top plate and the inner volute top plate.

[0011] Furthermore, the outer volute top plate is a solid plate, and the inner volute top plate is a porous mesh plate.

[0012] Furthermore, an air inlet is provided on the front side plate, and the radial clearance between the air inlet and the impeller is 3mm-5mm.

[0013] Furthermore, the volute is a narrow volute structure with an axial dimension of 340-350 mm.

[0014] Furthermore, it also includes an electric motor for driving the impeller to rotate; the electric motor is mounted on a mounting bracket, and the front end cover of the electric motor extends into the volute.

[0015] Furthermore, the rear wheel disc has an inclined structure within a diameter range of 80mm, with an inclination angle γ of 8°-12°; blades for cooling the front end of the motor are provided in the inclined area of ​​the rear wheel disc, and a liquid circulation mechanism for cooling the motor body and rear end are connected to the motor body.

[0016] The application of the technical solution of the present invention has the following beneficial effects:

[0017] (1) The present invention provides a centrifugal fan that optimizes the internal flow field of the impeller by using airfoil-type blades on the impeller and making reasonable selection of the inlet and outlet angles of the blades, thereby reducing separation and impeller outlet losses and improving flow rate and fan efficiency.

[0018] (2) In this invention, the blade inlet side is inclined to reduce airflow impact, and the airflow flows smoothly in the impeller channel, reducing vortex noise.

[0019] (3) In this invention, the volute includes a double-layer volute top plate and front and rear side plates disposed opposite to each other on both sides of the double-layer volute top plate; the double-layer volute top plate includes an outer volute top plate and an inner volute top plate; sound-absorbing material is provided between the outer volute top plate and the inner volute top plate. By providing a double-layer volute top plate and sound-absorbing material, the airflow noise flowing through the volute channel can be better absorbed, thereby achieving the purpose of noise reduction.

[0020] (4) In this invention, the volute is a narrow volute structure with an axial dimension of 340-350mm, which is 25%-30% narrower than the width of a conventional volute. On the one hand, it can reduce the vortex noise in the part of the volute near the front side plate, thereby solving the problem of high noise in existing fans; on the other hand, due to the limitations of locomotive space and layout, the narrow volute structure can better meet the installation requirements.

[0021] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0022] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0023] Figure 1 This is a schematic diagram of the centrifugal fan of the present invention;

[0024] Figure 2 This is a schematic diagram of the cross-sectional structure of the impeller;

[0025] Figure 3 yes Figure 1 Side view;

[0026] Figure 4 This is a schematic diagram of the impeller and volute assembled together;

[0027] Among them, 1. Impeller, 1.1. Wheel body, 1.1.1. Front impeller, 1.1.2. Rear impeller, 1.1.3. Blade 1, 1.1.4. Blade 2, 1.2. Wheel core, 2. Volute, 2.1. Outer volute top plate, 2.2. Inner volute top plate, 2.3. Sound-absorbing material, 2.4. Front side plate, 2.5. Rear side plate, 3. Air inlet, 4. Motor, 5. Mounting bracket. Detailed Implementation

[0028] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.

[0029] Example:

[0030] See Figure 1 and Figure 2 A centrifugal fan includes an impeller 1, the impeller 1 including a wheel body 1.1 and a wheel core 1.2, the wheel body 1.1 and the wheel core 1.2 being connected;

[0031] The wheel body 1.1 includes a front wheel disc 1.1.1, a rear wheel disc 1.1.2, and multiple blades 1.1.3 disposed between the front wheel disc 1.1.1 and the rear wheel disc 1.1.2. The rear wheel disc 1.1.2 is connected to the wheel core 1.2. (See also...) Figure 4 The exit angle α of the blade 1.1.3 is 45°-55°, and in this embodiment, α is preferably 55°.

[0032] In this embodiment, preferably, the blade 1.1.3 is an airfoil blade with an inclined structure on its inlet side and an angle β between the inlet side and the axis of rotation of 10°.

[0033] Preferably, the number of leaves 1.1.3 is 12.

[0034] By using airfoil-type blades on impeller 1 and making reasonable selections for the inlet and outlet angles of the blades (1.1.3), the internal flow field of impeller 1 is further optimized, reducing separation and outlet losses of impeller 1, and improving flow rate and fan efficiency.

[0035] See Figure 1 and Figure 3 In this embodiment, the centrifugal fan also includes a volute 2, which includes a double-layer volute top plate and a front side plate 2.4 and a rear side plate 2.5 disposed opposite to each other on both sides of the double-layer volute top plate;

[0036] The double-layer volute top plate includes an outer volute top plate 2.1 and an inner volute top plate 2.2; a sound-absorbing material 2.3 is disposed between the outer volute top plate 2.1 and the inner volute top plate 2.2. In this embodiment, the sound-absorbing material 2.3 is detachably installed between the outer volute top plate 2.1 and the inner volute top plate 2.2; the sound-absorbing material 2.3 is polyester fiber.

[0037] By setting a double-layer volute top plate and sound-absorbing material 2.3, the noise of the airflow passing through the volute channel can be better absorbed, thereby achieving the purpose of noise reduction.

[0038] Preferably, the outer volute top plate 2.1 is a solid plate, and the inner volute top plate 2.2 is a perforated mesh plate. This arrangement allows more airflow noise to pass through the inner volute top plate 2.2 and be filtered by the sound-absorbing material 2.3, achieving a better noise reduction effect.

[0039] In this embodiment, an air inlet 3 is provided on the front side plate 2.4, and the radial gap between the air inlet 3 and the impeller 1 is 3mm-5mm.

[0040] In this embodiment, the volute 2 is a narrow volute structure with an axial dimension of 340-350mm, which is 25%-30% narrower than the width of a conventional volute. Setting the volute 2 as a narrow volute structure reduces eddy current noise near the front side plate 2.4 inside the volute 2, thus solving the problem of excessive noise in existing fans. Furthermore, due to space and layout limitations of the locomotive, the narrow volute structure better meets installation requirements.

[0041] See Figure 1 and Figure 2In this embodiment, the centrifugal fan also includes a motor 4 for driving the impeller 1 to rotate; the motor 4 is mounted on a mounting bracket 5, and the front end cover of the motor 4 extends into the volute 2. The rear impeller 1.1.2 has an inclined structure within a diameter range of 80mm, with an inclination angle γ of 8°-12°; blades 1.1.4 for cooling the front end of the motor 4 are provided in the inclined area of ​​the rear impeller 1.1.2, and the main body and rear end of the motor 4 are connected to a liquid circulation mechanism for cooling it. In this embodiment, the number of blades 1.1.4 is 8, and the liquid circulation mechanism is a water cooling circulation mechanism.

[0042] Comparative Example 1:

[0043] Unlike the embodiments, no sound-absorbing material was used in this comparative example.

[0044] Comparative Example 2:

[0045] The difference from the embodiment is that the impeller does not use airfoil blades.

[0046] Comparative Example 3:

[0047] The difference from the embodiment is that the volute is 25%-30% wider than that of the embodiment.

[0048] Comparative Example 4: Commercially available centrifugal fans.

[0049] The centrifugal fan in this embodiment and the fan in the comparative example were subjected to total pressure efficiency tests, noise tests, and pressure tests, respectively. The total pressure efficiency test used the ratio of impeller power to motor shaft power as the total pressure efficiency. The noise test used the 9-point method required by GB3767 to measure the fan noise power. The pressure test used an outlet test according to GB1236 to measure the pressure at the rated flow rate. The test results are shown in the table below under a flow rate of 8 m³ / s.

[0050] Full pressure 6800Pa 6800Pa 6000Pa 5800 5800Pa Total pressure efficiency 80％ 80％ 72％ 74％ 70％ noise 109dB 111dB 112dB 110dB 113dB

[0051] As shown in the table above, under the condition of a flow rate of 8 m³ / s, the centrifugal fan provided in this embodiment can reach a pressure of 6800 Pa, exceeding 6000 Pa, and its efficiency is improved to 80%, while the noise is also reduced and controlled within the range of 109 dB. In summary, the centrifugal fan provided by this invention can meet the requirements for locomotive use.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A centrifugal fan, characterized in that it includes an impeller (1), the impeller (1) including a wheel body (1.1) and a wheel core (1.2), the wheel body (1.1) and the wheel core (1.2) being connected; The wheel body (1.1) includes a front wheel disc disposed opposite to the wheel. 1.1.1), a rear wheel disc (1.1.2), and a multi-blade assembly (1.1.3) disposed between the front wheel disc (1.1.1) and the rear wheel disc (1.1.2), wherein the rear wheel disc (1.1.2) is connected to the wheel core (1.2); the exit angle α of the multi-blade assembly (1.1.3) is 45°-55°; The first blade (1.1.3) is an airfoil blade with an inclined structure on its inlet side and an angle β between the inlet side and the axis of rotation of 8°-10°. It also includes a volute (2), which is a narrow volute structure with an axial dimension of 340-350 mm; The volute (2) includes a double-layer volute top plate and a front side plate (2.4) and a rear side plate (2.5) disposed opposite to each other on both sides of the double-layer volute top plate. The double-layer volute top plate includes an outer volute top plate (2.1) and an inner volute top plate (2.2); a sound-absorbing material (2.3) is provided between the outer volute top plate (2.1) and the inner volute top plate (2.2). The outer volute top plate (2.1) is a solid plate, and the inner volute top plate (2.2) is a perforated mesh plate.

2. The centrifugal fan according to claim 1, characterized in that, The number of blades (1.1.3) is 12.

3. The centrifugal fan according to claim 1, characterized in that, An air inlet (3) is provided on the front side plate (2.4), and the radial gap between the air inlet (3) and the impeller (1) is 3mm-5mm.

4. The centrifugal fan according to claim 1, characterized in that, It also includes an electric motor (4) for driving the impeller (1) to rotate; the electric motor (4) is mounted on a mounting bracket (5), and the front end cover of the electric motor (4) extends into the volute (2).

5. The centrifugal fan according to claim 4, characterized in that, The rear wheel disc (1.1.2) is inclined within a diameter range of 80mm, with an inclination angle γ of 8°-12°; a blade (1.1.4) is provided in the inclined area of ​​the rear wheel disc (1.1.2) for cooling the front end of the motor (4), and the main body and rear end of the motor (4) are connected to a liquid circulation mechanism for cooling it.

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