Fan impeller with noise reduction function

Abstract

The centrifugal fan impeller with the noise reduction function comprises a bottom plate and a face plate, a circular wheel disc is arranged on the bottom plate, a plurality of first blades and second blades are fixed between the bottom plate and the face plate, the first ends of the first blades are fixed on the bottom plate, the second ends of the first blades are fixed on the face plate, and the second ends of the second blades are fixed on the face plate. The multiple first blades are distributed between the bottom plate and the panel around the wheel disc, the multiple first blades are distributed on the periphery of the wheel disc in an annular array mode, the outer side ends of the multiple first blades all fall on the round edge of the same circular ring, the second blades are located between every two adjacent first blades, and the length of the first blades is larger than that of the second blades.

Description

Technical Field

[0001] The utility model relates to the field of centrifugal fans, in particular to a fan impeller with a noise reduction function. Background Art

[0002] Centrifugal fan, a machine that relies on input mechanical energy to increase gas pressure and discharge gas, is a driven fluid machine. Centrifugal fans are widely used in industry. Centrifugal fans are widely used in factories, mines, tunnels, cooling towers, vehicles, ships and buildings for ventilation, dust removal and cooling; ventilation and air induction of boilers and industrial furnaces; cooling and ventilation in air conditioning equipment and household appliances; drying and selection of grains; wind tunnel wind source and inflation and propulsion of hovercraft, etc.

[0003] Centrifugal fans are based on the principle of converting kinetic energy into potential energy. They use a high-speed rotating impeller to accelerate the gas, then decelerate and change the flow direction, so that the kinetic energy is converted into potential energy, that is, pressure. In a single-stage centrifugal fan, the gas enters the impeller from the axial direction, changes to the radial direction when passing through the impeller, and then enters the diffuser. In the diffuser, the gas changes the flow direction and the cross-sectional area of ​​the pipe increases, which slows down the airflow. This deceleration effect converts kinetic energy into pressure energy. The pressure increase mainly occurs in the impeller, and secondly in the expansion process. In a multi-stage centrifugal fan, a return flow device is used to allow the airflow to enter the next impeller, generating higher pressure.

[0004] The existing 4-72 series centrifugal fans have the characteristics of moderate total pressure and high efficiency, and are widely used in places where the resistance of the air duct system is not high and a large air volume is required. However, for the sake of manufacturing convenience, cost control and wear reduction, most manufacturers have modified the original backward airfoil impeller blades to backward straight plate type. This change also makes the existing centrifugal fans very noisy, making it difficult to use them in places with noise restrictions, greatly limiting their application scenarios. Utility Model Content

[0005] Based on this, it is necessary to provide a fan impeller with a noise reduction function.

[0006] To solve the above technical problems, the utility model provides a fan impeller with a noise reduction function, comprising a base plate and a panel, a circular wheel disc is arranged on the base plate, a plurality of first blades and a second blade are fixed between the base plate and the panel, a first end of the first blade is fixed on the base plate, and a second end of the first blade is fixed on the panel, a plurality of the first blades are distributed between the base plate and the panel around the wheel disc, a plurality of the first blades are distributed around the wheel disc in a circular array, the outer ends of the plurality of the first blades all fall on the circular edge of the same circular ring, the second blade is located between two adjacent first blades, and the length of the first blade is greater than the length of the second blade.

[0007] Preferably, the number of the second blades corresponds to the number of the first blades, the second blades are distributed around the wheel disc between the base plate and the panel, the first ends of the second blades are fixed to the base plate, and the second ends of the second blades are fixed to the panel.

[0008] Preferably, both the first blade and the second blade are flat blades.

[0009] Preferably, the ratio of the length of the first blade to the length of the second blade is (3.5-4.2):1.

[0010] Preferably, the outer ends of the plurality of second blades all fall on the circular edge of the same circular ring, and the circular ring where the outer ends of the first blades are located is the same as the circular ring where the outer ends of the second blades are located.

[0011] Preferably, there is an angle between the plane where the second blade is located and the plane where the first blade is located, and the value range of the angle is 35-50 degrees.

[0012] Preferably, a plurality of the first blades are evenly distributed around the wheel disc, and a plurality of the second blades are evenly distributed around the wheel disc.

[0013] Preferably, the number of the first blades is ten.

[0014] Preferably, the angle between the plane where the first blade is located and the tangent line of the circular ring is 40 degrees.

[0015] The beneficial effects of the utility model are as follows: the utility model changes the outlet angle of the impeller blades of the fan, so that the vortex existing near the impeller blades is greatly reduced in size, thereby reducing the sound emitted in the form of sound waves when the vortex dissipates energy, thereby achieving a noise reduction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other purposes, features and advantages of the present invention will become more apparent through a more specific description of the preferred embodiments of the present invention shown in the accompanying drawings. The same reference numerals in all the accompanying drawings indicate the same parts, and the drawings are not intentionally scaled to the actual size, but the focus is on illustrating the subject matter of the present invention.

[0017] Figure 1 It is a schematic diagram of the overall structure of a preferred embodiment of the utility model;

[0018] In the figure: a first blade 1; a second blade 2; a ring 3; a shell 4; and a wheel 5. DETAILED DESCRIPTION

[0019] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings.

[0020] It should be noted that when an element is considered to be "connected" to another element, it may be directly connected to another element and integrated therewith, or there may be an intermediate element at the same time. The terms "installed", "one end", "the other end" and similar expressions used herein are for illustrative purposes only.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art. The terms used in the specification herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0022] refer to Figure 1 The utility model provides a centrifugal fan impeller with noise reduction function, including a bottom plate and a panel located in the housing 4, a circular wheel disc is arranged on the bottom plate, a plurality of first blades 1 and a first blade 2 are fixed between the bottom plate and the panel, a first end of the first blade 1 is fixed on the bottom plate, a second end of the first blade 1 is fixed on the panel, a plurality of the first blades 1 are distributed between the bottom plate and the panel around the wheel disc, the outer ends of the plurality of the first blades 1 all fall on the circular edge of the same ring 3, a plurality of the first blades 1 are distributed around the wheel disc in an annular array, the first blade 2 is located between two adjacent first blades 1, and the length of the first blade 1 is greater than the length of the first blade 2. The centrifugal fan impeller of the present application is a backward straight plate type. The present scheme adjusts the angle of the impeller blade by adding the first blade 2 on the basis of the first blade 1, so that the angle of the blade and the outflowing airflow tends to be consistent, that is, the streamline of the blade and the outflowing airflow tends to be consistent, so that the number and scale of the vortex generated by the airflow are greatly reduced, so that the noise generated will be greatly reduced.

[0023] In a preferred embodiment, the number of the first blades 2 corresponds to the number of the first blades 1, the first blades 2 are distributed around the wheel disc between the base plate and the panel, the first ends of the first blades 2 are fixed to the base plate, and the second ends of the first blades 2 are fixed to the panel.

[0024] In a preferred embodiment, both the first blade 1 and the first blade 2 are flat blades.

[0025] In a preferred embodiment, the ratio of the length of the first blade 1 to the length of the first blade 2 is (3.5-4.2):1. Optimally, when the ratio of the length of the first blade 1 to the length of the first blade 2 is 4:1, the combination of the first blade 1 and the first blade 2 has the best effect and the best noise reduction effect. If the length of the first blade 2 is too long, the friction resistance will increase and the wind volume and wind pressure will be reduced. If the length of the first blade 2 is too short, it will not be able to do work on the outflowing airflow and cannot increase the wind volume and wind pressure. When the length of the first blade 2 is 25% of the length of the first blade 1 and is located at the outermost edge of the impeller, the wind volume and wind pressure are the highest, thereby forming a layout of 10 main long blades and 10 secondary short blades of the impeller. When the length of the first blade 2 is 25% of the length of the first blade 1 and is located at the outermost edge of the impeller, numerical simulation of CFD computational fluid dynamics software is performed, and the results show that the vortex at the working point is greatly reduced, the scale is greatly reduced (turbulence intensity, turbulent kinetic energy, turbulence dissipation rate), and the acoustic noise value is significantly reduced.

[0026] like Figure 1 As shown, the first blade 2 is located at the outermost edge of the impeller, that is, the circular ring 3 where the outer end of the first blade 1 is located is the same as the circular ring 3 where the outer end of the first blade 2 is located, that is, on the basis that the length of the first blade 1 is greater than the length of the first blade 2, the inner end of the first blade 2 is not flush with the inner end of the first blade 1. The circular ring 3 here is a circular ring in which the outer ends of multiple first blades 1 all fall on the circular edge of the same circular ring 3, and at the same time, the outer ends of multiple second blades 2 all fall on the circular edge of the same circular ring 3; at this time, the condition that the second blade is located at the outermost edge of the impeller is met.

[0027] In a preferred embodiment, the outer ends of the plurality of first blades 2 all fall on the circular edge of the same circular ring 3 , and the circular ring 3 where the outer end of the first blade 1 is located is the same as the circular ring 3 where the outer end of the first blade 2 is located.

[0028] In a preferred embodiment, there is an angle between the plane where the first blade 2 is located and the plane where the first blade 1 is located, and the value range of the angle is 35-50 degrees.

[0029] In a preferred embodiment, a plurality of the first blades 1 are evenly distributed around the wheel disc, and a plurality of the first blades 2 are evenly distributed around the wheel disc.

[0030] like Figure 1 As shown, in a preferred embodiment, the angle between the plane where the first blade 1 is located and the tangent line of the ring 3 is 40 degrees. Optionally, the first blade 1 is a straight impeller blade, and the angle between the plane where the first blade 1 is located and the tangent line of the ring 3 is the outlet angle of the airflow. Under the condition near the highest efficiency point of the fan, that is, when the fan is at 7500m 3 Under the working condition near the working point of / h, the outlet angle is adjusted to 40° to make it consistent with the angle of the outflowing airflow, and the vortex is greatly reduced.

[0031] In a preferred embodiment, the number of the first blades 1 is 10. The first blade 1 is the main blade of the centrifugal fan, and the first blade 2 is the auxiliary blade of the centrifugal fan. Since the outlet angle of the first blade 1 affects the aerodynamic performance of the fan, the air volume and air pressure will be reduced. In order to compensate and improve the air volume and air pressure, one more first blade 2 is inserted between the 10 first blades 1.

[0032] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0033] In the description of this specification, the description with reference to the terms "preferred embodiment", "further embodiment", "other embodiments" or "specific example" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0034] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A fan impeller with noise reduction function, characterized in that: It includes a base plate and a panel, a circular wheel disc is arranged on the base plate, a plurality of first blades and a second blade are fixed between the base plate and the panel, a first end of the first blade is fixed on the base plate, a second end of the first blade is fixed on the panel, a plurality of the first blades surround the wheel disc and are distributed between the base plate and the panel, a plurality of the first blades are distributed around the wheel disc in a ring array, the outer ends of the plurality of the first blades all fall on the circular edge of the same ring, the second blade is located between two adjacent first blades, the length of the first blade is greater than the length of the second blade; there is an angle between the plane where the second blade is located and the plane where the first blade is located, and the value range of the angle is 35-50 degrees; the angle between the plane where the first blade is located and the tangent of the ring is 40 degrees.

2. The fan impeller according to claim 1, characterized in that: The number of the second blades corresponds to the number of the first blades. The second blades surround the wheel and are distributed between the bottom plate and the panel. The first ends of the second blades are fixed to the bottom plate, and the second ends of the second blades are fixed to the panel.

3. The fan impeller according to claim 1, characterized in that: The first blade and the second blade are both flat blades.

4. The fan impeller according to claim 3, characterized in that: The ratio of the length of the first blade to the length of the second blade is (3.5-4.2):

1.

5. The fan impeller according to claim 4, characterized in that: The outer ends of the second blades both fall on the circular edge of the same circular ring, and the circular ring where the outer ends of the first blades are located is the same as the circular ring where the outer ends of the second blades are located.

6. The fan impeller according to claim 1, characterized in that: A plurality of the first blades are evenly distributed around the wheel disc, and a plurality of the second blades are evenly distributed around the wheel disc.

7. The fan impeller according to claim 6, characterized in that: The number of the first blades is 10.

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