CN215927827U - Noise-reduction axial flow fan - Google Patents

Abstract

The utility model relates to a noise-reducing axial flow fan which comprises a cylindrical shell, wherein one end of the shell is provided with a fan inlet, the other end of the shell is provided with a fan outlet, a movable impeller and a fixed impeller which are connected through a rotating shaft are arranged in the shell, and the fixed impeller faces the fan outlet; the outer sides of the shell corresponding to the four positions of the fan inlet, the fan outlet, the movable impeller and the stationary impeller are provided with porous noise reduction materials, and the porous noise reduction materials comprise at least one of polyurethane foam, glass fibers and cotton felt. The noise reduction materials with different types and thicknesses can be flexibly selected at the outer sides of four different positions of a bell mouth, a movable impeller, a stationary impeller and a diffuser of the fan according to the requirements of noise reduction amount of the fan, running environment of the fan, economic cost and the like, and optimal combination is obtained for noise reduction of the fan, so that the production work requirement is met.

Description

Noise-reduction axial flow fan

Technical Field

The utility model relates to the technical field of ventilators, in particular to a noise-reducing axial flow fan.

Background

The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.

The thermal power plant uses large-scale axial-flow fan as the equipment in production, can radiate the industrial noise of well high intensity to the surrounding environment when operation, influences the surrounding environment, causes very big health hazard for the staff simultaneously.

The noise component of the axial flow fan mainly comprises: aerodynamic noise, vibration noise, and electromagnetic noise. The progress of modern technology makes the electromagnetic noise generated by the motor power-on and periodic excitation of electromagnetic field during the motor driving impeller motion be negligible, and the aerodynamic noise caused by pressure pulsation generated by high-speed operation of the fan and the vibration noise radiated to the surroundings by the vibration sources such as the air flow excitation blade, the volute, the motor and the inlet and outlet pipeline are difficult to eliminate or reduce.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems, the noise reduction axial flow fan provided by the utility model flexibly selects noise reduction materials with different types and thicknesses at the outer sides of four different positions of a bell mouth, a movable impeller, a stationary impeller and a diffuser of the fan to obtain an optimal combination for fan noise reduction so as to meet the production work requirement.

In order to achieve the purpose, the utility model adopts the following technical scheme:

the utility model provides a noise reduction axial flow fan, which comprises a cylindrical shell, wherein one end of the shell is provided with a fan inlet, the other end of the shell is provided with a fan outlet, a movable impeller and a fixed impeller which are connected through a rotating shaft are arranged in the shell, and the fixed impeller faces the fan outlet; the outer sides of the shell corresponding to the four positions of the fan inlet, the fan outlet, the movable impeller and the stationary impeller are provided with porous noise reduction materials, and the porous noise reduction materials comprise at least one of polyurethane foam, glass fibers and cotton felt.

The fan inlet is in a horn shape with gradually reduced diameter, and one end with smaller diameter is connected with the shell.

The outlet of the fan is provided with a diffusion cylinder which is connected with one end of the shell; the diameter of one end of the diffuser, which is connected with the shell, is not larger than that of the end far away from the shell.

The movable impeller is connected with the motor, air enters from the inlet of the fan, is pressurized by the movable impeller driven by the motor, and is blown out from the diffuser at the outlet of the fan after being guided by the stationary impeller.

The polyurethane foam has a thickness in the range of 125mm to 150 mm.

The thickness of the glass fiber ranges from 100mm to 150 mm.

The thickness of the cotton felt ranges from 200mm to 250 mm.

Compared with the prior art, the above one or more technical schemes have the following beneficial effects:

the noise reduction materials with different types and thicknesses can be flexibly selected at the outer sides of four different positions of a bell mouth, a movable impeller, a stationary impeller and a diffuser of the fan according to the requirements of noise reduction amount of the fan, running environment of the fan, economic cost and the like, and optimal combination is obtained for noise reduction of the fan, so that the production work requirement is met.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the utility model, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the utility model and together with the description serve to explain the utility model and not to limit the utility model.

FIG. 1 is a schematic diagram of the overall structure provided by one or more embodiments of the present invention;

FIG. 2 is a schematic diagram of a side-view structure provided by one or more embodiments of the present invention;

FIG. 3 is a schematic cross-sectional overall structure provided by one or more embodiments of the present invention;

FIG. 4 is a schematic structural diagram of a sound field calculation model provided by one or more embodiments of the present invention;

fig. 5(a) is a schematic diagram of a noise reduction curve at the bell mouth 1 according to one or more embodiments of the present invention;

FIG. 5(b) is a graph illustrating a noise reduction curve at the moving impeller 2 according to one or more embodiments of the present invention;

fig. 5(c) is a graph illustrating a noise reduction amount at the stationary vane 3 according to one or more embodiments of the present invention;

FIG. 5(d) is a graphical illustration of the noise reduction at the diffuser 4 provided by one or more embodiments of the present invention;

in the figure: 1. a bell mouth; 2. a movable impeller; 3. a stationary impeller; 4. a pressure expansion cylinder; 11. a shell 12, a porous noise reduction material 13, a sound field calculation domain 14 and an ideal matching layer.

Detailed Description

The utility model is further described with reference to the following figures and examples.

It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the utility model as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the utility model. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The noise component of the axial flow fan mainly comprises: aerodynamic noise, vibration noise, and electromagnetic noise. The pneumatic noise is caused by pressure pulsation generated by high-speed operation of the fan, and the pulsation source mainly has periodic action of the rotating blades and surrounding gas and vortex splitting and shedding on the surfaces of the blades. The vibration noise is mainly radiated to the periphery by vibration sources such as airflow exciting vanes, a volute, a motor, inlet and outlet pipelines and the like. The improvement of modern technology enables electromagnetic noise generated by periodic excitation of an electromagnetic field to be ignored, meanwhile, the shell of the axial flow fan has a sound insulation effect to a certain degree, pneumatic noise mainly radiates to the outside along the axial direction of the fan, and vibration noise becomes an important component of noise of a large-scale axial flow fan of a generator set of an actual power plant.

The first embodiment is as follows:

as shown in fig. 1-5, a noise reduction axial flow fan comprises a cylindrical housing, one end of the housing is provided with a fan inlet, the other end of the housing is provided with a fan outlet, a movable impeller 2 and a stationary impeller 3 connected through a rotating shaft are arranged in the housing, and the movable impeller 2 is connected with a motor; the outer side of the shell is positioned at a fan inlet and a fan outlet, and porous noise reduction materials are arranged at the positions of the movable impeller 2 and the stationary impeller 3 and comprise at least one of polyurethane foam, glass fiber and cotton felt.

In this embodiment, the diameter of the fan inlet is gradually reduced, the end with the smaller diameter is connected to the housing, and the fan inlet forms the bell mouth 1 in fig. 1-2.

The fan outlet is provided with a diffusion cylinder 4, and the diameter of one end, connected with the shell, of the diffusion cylinder 4 is not more than that of the end far away from the shell.

Air enters from the inlet of the fan, is pressurized by the movable impeller 2 driven by the motor, is blown out from the diffuser 4 at the outlet of the fan after being guided by the fixed impeller 3, and the fixed impeller 3 twists the rotating airflow flowing out from the driven impeller 2, so that part of the kinetic energy of the deflected airflow is changed into static pressure energy, and meanwhile, the resistance loss caused by the rotation of the airflow is reduced, thereby reducing the noise of the fan.

The type and the thickness of the porous noise reduction material are obtained according to a calculation model of a sound field where the fan is located, the four parts of the bell mouth 1, the movable impeller 2, the stationary impeller 3 and the diffuser 4 of the fan shell wrap the porous noise reduction materials of different types according to the noise reduction requirement, and the radiation vibration noise of the machine shell to the periphery is reduced through the sound absorption and noise reduction effects of the porous noise reduction materials.

In this embodiment, the used material of fan shell is 18mm steel sheet integral welding, and the wheel hub is first both ends and is applyed fixed restraint. As shown in fig. 4, a porous noise reduction material 12 is wrapped outside a casing 11, a rectangular parallelepiped wrapping region of 1.5m is created outside the casing to serve as a sound field calculation region 13, and an outermost ideal matching layer 14 is used for wave absorption, so that vibration noise calculation of a target axial flow fan is performed on the basis of an acoustic calculation model, and noise reduction materials of various parts of the fan can be flexibly combined by changing evaluation parameters and material thicknesses of the porous noise reduction material 12, so that an optimal noise reduction scheme is obtained on the basis of meeting noise reduction quantity.

As shown in fig. 5(a) - (d), the polyurethane foam, the glass fiber and the cotton felt have noise reduction effects to different degrees at four different positions of the bell mouth 1, the movable impeller 2, the stationary impeller 3 and the diffuser 4 of the target axial flow fan. Different noise reduction materials can be flexibly selected at the four different positions of the fan according to the requirements of the fan on noise reduction quantity, fan operation environment, economic cost and the like, and optimal combination is obtained for fan noise reduction so as to meet the production work requirement.

For example, the noise reduction effect of the glass fiber at the bell mouth 1 (fan inlet) is better than that of polyurethane foam and cotton felt at the thickness of 0-400mm, so the noise reduction material outside the bell mouth 1 (fan inlet) is preferably the glass fiber.

For example, when the total noise of the fan is 136dB, the requirement of the fan operating environment is 110dB, and the total noise reduction requirement of the fan is 26dB, then:

the bell mouth 1 is made of glass fiber, and the thickness of the bell mouth is 100mm-150 mm;

the movable impeller 2 is made of polyurethane foam, and the selectable thickness is 125mm-150 mm;

the stationary impeller 3 is made of cotton felt, and the selectable thickness is 200mm-250 mm;

the material glass fiber is selected for the pressure expansion cylinder 4, and the selectable thickness is 100mm-150 mm;

according to the noise superposition principle, the combination is the optimal noise reduction material combination under the scene that the total noise is 136dB, the requirement of the running environment of the fan is 110dB and the requirement of the total noise reduction amount of the fan is 26dB when the fan runs.

The four different positions of the bell mouth 1, the movable impeller 2, the stationary impeller 3 and the diffuser 4 of the fan respectively select one of polyurethane foam, glass fiber and cotton felt as a noise reduction material according to the different noise reduction requirements.

According to the noise reduction fan with the structure, noise reduction materials of different types and thicknesses can be flexibly selected at the outer sides of the horn mouth, the movable impeller, the stationary impeller and the diffuser of the fan at four different positions according to requirements of noise reduction amount, fan operation environment, economic cost and the like of the fan, optimal combination is obtained, and noise reduction of the fan is carried out, so that production work requirements are met.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The utility model provides an axial fan that makes an uproar falls which characterized in that: the fan comprises a cylindrical shell, wherein one end of the shell is provided with a fan inlet, the other end of the shell is provided with a fan outlet, a movable impeller and a fixed impeller which are connected through a rotating shaft are arranged in the shell, and the fixed impeller faces the fan outlet; the outer sides of the shell corresponding to the four positions of the fan inlet, the fan outlet, the movable impeller and the stationary impeller are provided with porous noise reduction materials, and the porous noise reduction materials comprise at least one of polyurethane foam, glass fibers and cotton felt.

2. A noise-reducing axial flow fan according to claim 1, wherein: the fan inlet is in a horn shape with the diameter gradually reduced.

3. A noise-reducing axial flow fan according to claim 2, wherein: and the end with the smaller diameter of the fan inlet is connected with the shell.

4. A noise-reducing axial flow fan according to claim 1, wherein: the fan outlet has a diffuser.

5. The noise-reducing axial flow fan according to claim 4, wherein: the diffusion cylinder is connected with one end of the shell.

6. A noise-reducing axial flow fan according to claim 5, wherein: the diameter of one end, connected with the shell, of the diffuser is not larger than that of the end far away from the shell.

7. A noise-reducing axial flow fan according to claim 1, wherein: the movable impeller is connected with the motor, air enters from the inlet of the fan, is pressurized by the movable impeller driven by the motor, and is blown out from the diffuser at the outlet of the fan after being guided by the stationary impeller.

8. A noise-reducing axial flow fan according to claim 1, wherein: the polyurethane foam has a thickness in the range of 125mm to 150 mm.

9. A noise-reducing axial flow fan according to claim 1, wherein: the thickness range of the glass fiber is 100mm-150 mm.

10. A noise-reducing axial flow fan according to claim 1, wherein: the thickness range of the cotton felt is 200mm-250 mm.

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