Multi-wing centrifugal fan

Abstract

The utility model belongs to the technical field of centrifugal fans, and discloses a multi-wing centrifugal fan. The multi-wing centrifugal fan comprises an impeller, a volute and a radial partition plate. The impeller comprises a rotating disc, a fixing ring and a plurality of blades, the rotating disc sleeves the rotating shaft, the blades are distributed at intervals in the peripheral direction of the rotating disc, and the fixing ring and the rotating disc are oppositely arranged to fix the two axial ends of the blades and the rotating shaft respectively. A containing cavity and an air outlet cavity which are communicated are formed in the volute, the impeller is located in the containing cavity, and the radial partition plate is located in the air outlet cavity and divides the air outlet cavity into an inner cavity facing the impeller and an outer cavity deviating from the impeller. The multi-wing centrifugal fan is good in performance and low in noise.

Description

Technical Field

[0001] This utility model relates to the field of centrifugal fan technology, and in particular to a multi-blade centrifugal fan. Background Technology

[0002] Multi-blade centrifugal fans are a specially designed type of centrifugal fan, typically employing a dense impeller structure composed of multiple forward-curved short blades. Multi-blade centrifugal fans can provide a large air volume and moderate air pressure at low speeds while maintaining low noise levels, making them widely used in ventilation and cooling applications, such as in automotive air conditioning power components.

[0003] Existing multi-blade centrifugal fans suffer from complex volute structures due to limitations in space, design, and performance. This leads to uneven airflow from the impeller into the volute, and even abnormal rotation or backflow within the volute. For example, after the airflow exits the impeller, two opposing airflows may form inside the volute, influencing each other and creating vortices. Figure 1 The flow field diagram inside the volute shows the vortices formed inside the volute within the dashed box, which leads to a decrease in fan performance and an increase in noise, ultimately resulting in high energy consumption and high noise during fan operation.

[0004] Therefore, there is an urgent need to develop a multi-blade centrifugal fan to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a multi-blade centrifugal fan that has good performance and low noise.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] Multi-blade centrifugal fans, including:

[0008] An impeller, comprising a turntable, a fixed ring, and multiple blades, wherein the turntable is sleeved on a rotating shaft, and the multiple blades are spaced apart along the outer circumference of the turntable, and the fixed ring and the turntable are arranged opposite to each other to fix the blades at both ends along the axial direction of the rotating shaft respectively;

[0009] The volute has a communicating receiving cavity and an air outlet cavity, and the impeller is located in the receiving cavity;

[0010] A radial baffle, located in the air outlet cavity, divides the air outlet cavity into an inner cavity facing the impeller and an outer cavity facing away from the impeller.

[0011] As an optional technical solution for multi-blade centrifugal fans, the rotating shaft, the turntable, and the fixed ring are all coaxially arranged, and the multiple blades are evenly distributed along the outer circumference of the turntable.

[0012] As an optional technical solution for a multi-blade centrifugal fan, the radial baffle extends from the starting point toward the outlet of the volute to the end point, the end point being beyond the outlet of the volute; or, the end point being flush with the outlet of the volute; or, the end point being located within the air outlet cavity and spaced apart from the outlet of the volute.

[0013] As an optional technical solution for a multi-blade centrifugal fan, on the cross-section of the volute perpendicular to the rotating shaft, the center point of the rotating shaft is point O, and the location of the volute tongue is point A. With the distance OA between point O and point A as the radius, the blade rotates along the rotation direction by a preset angle α to reach point B. The extension line connecting point O and point B intersects the volute at point C. The starting point is located between points B and C, and 150°≤α≤270°.

[0014] As an optional technical solution for multi-blade centrifugal fans, the cross-section of the outer cavity is of uniform cross-section along the airflow direction in the outlet cavity; or,

[0015] Along the direction of airflow in the air outlet cavity, the cross-section of the outer cavity gradually narrows; or;

[0016] Along the direction of airflow in the air outlet cavity, the cross-section of the outer cavity gradually expands; or,

[0017] Along the flow direction of the airflow in the air outlet cavity, the cross-section of the outer cavity exhibits a shape that first expands and then contracts; or,

[0018] Along the flow direction of the airflow in the air outlet cavity, the cross-section of the outer cavity first narrows and then expands.

[0019] As an optional technical solution for multi-blade centrifugal fans, the ratio of the radial width of the outer cavity to the radial width of the outlet cavity is in the range of 0-0.9 along the airflow direction in the outlet cavity.

[0020] As an optional technical solution for multi-blade centrifugal fans, the radial baffle abuts against the inner wall of the volute at both ends along the axial direction of the rotating shaft.

[0021] As an optional technical solution for multi-blade centrifugal fans, the surface of the radial baffle is arranged parallel to the rotating shaft; or,

[0022] The surface of the radial partition is inclined to the rotating shaft.

[0023] As an optional technical solution for multi-blade centrifugal fans, along the axial direction of the rotating shaft, the distance from the side surface of the turntable facing the fixed ring to the fixed ring is a first distance, and the value of the first distance gradually increases along the radial direction of the turntable from the rotating shaft to the outer peripheral edge of the turntable.

[0024] As an optional technical solution for multi-blade centrifugal fans, the number of radial baffles is multiple, and the multiple radial baffles are spaced apart along a direction perpendicular to the airflow direction to separate the air outlet cavity.

[0025] The beneficial effects of this utility model are:

[0026] The multi-blade centrifugal fan provided by this utility model includes an impeller, a volute, and radial baffles. The impeller includes a rotating disk, a fixed ring, and multiple blades. The rotating disk is sleeved on the rotating shaft, and the multiple blades are spaced apart along the outer circumference of the rotating disk. The fixed ring and the rotating disk are arranged opposite each other to fix the two ends of the blades respectively. The volute has a connected receiving cavity and an air outlet cavity. The impeller is located in the receiving cavity. Airflow can enter the impeller from the fixed ring side along the axial direction of the rotating shaft, and then be thrown out from the blade side (impeller), and enter the air outlet cavity from the receiving cavity. Because the radial baffle is located in the outlet cavity, it divides the outlet cavity into an inner cavity facing the impeller and an outer cavity facing away from the impeller. This causes the airflow in the outlet cavity to be split into two streams by the radial baffle, which enter the inner cavity and the outer cavity respectively, and then blow out of the volute. On the one hand, the radial baffle plays the role of guiding and splitting the flow, improving the flow field inside the volute, that is, confining the vortices formed inside the volute to the inner cavity, limiting their influence range, making the airflow distribution in the outer cavity of the volute more uniform, reducing the loss caused by the mixing of the two airflows in the inner and outer cavities, thereby improving the performance of the multi-blade centrifugal fan. On the other hand, the radial baffle inside the volute can reduce the aerodynamic noise generated by the multi-blade centrifugal fan during operation, and can also block some of the noise from propagating outward, thereby achieving the effect of noise reduction. Attached Figure Description

[0027] Figure 1 This is a flow field diagram inside the volute of a wind turbine in the background technology;

[0028] Figure 2 A schematic diagram of the multi-blade centrifugal fan structure provided in this embodiment of the utility model;

[0029] Figure 3 This is a schematic diagram of the airflow domain within the impeller and volute provided in an embodiment of the present invention;

[0030] Figure 4 This is a diagram showing the positions of the starting and ending points of the radial partition provided in this embodiment of the utility model;

[0031] Figure 5 This is a schematic diagram of the first structure of the impeller provided in this embodiment of the utility model;

[0032] Figure 6 This is a schematic diagram of the second structure of the impeller provided in this embodiment of the utility model;

[0033] Figure 7This is an assembly drawing of the volute and radial partition provided in this utility model embodiment;

[0034] Figure 8 This utility model embodiment provides a flow field diagram inside a multi-blade centrifugal fan.

[0035] In the picture:

[0036] 10. First airflow; 20. Second airflow;

[0037] 100 Impeller; 110 Turntable; 120 Fixed ring; 130 Blade; 140 Shaft; 200 Volute; 210 Receiving cavity; 220 Air outlet cavity; 221 Inner cavity; 222 Outer cavity; 230 Volute tongue; 300 Radial baffle; 310 Starting point. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0039] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0040] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0041] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0042] This embodiment provides a multi-blade centrifugal fan, which has good performance and low noise.

[0043] Specifically, such as Figures 2 to 8 As shown, the multi-blade centrifugal fan includes an impeller 100, a volute 200, and radial baffles 300. The impeller 100 includes a rotating disk 110, a fixing ring 120, and multiple blades 130. The rotating disk 110 is fitted onto a rotating shaft 140, which drives the rotating disk 110 to rotate. The multiple blades 130 are spaced apart along the outer circumference of the rotating disk 110. The fixing ring 120 and the rotating disk 110 are arranged opposite each other to fix the blades 130 at both ends of the axial direction of the rotating shaft 140. Typically, there are dozens of blades 130, forming a densely packed impeller 100. The volute 200 is shaped like a snail shell (spiral) and serves as the outer casing of the impeller 100. It guides the centrifugal airflow generated by the rotation of the impeller 100 along a spiral path, avoiding airflow turbulence and energy loss. At the same time, by gradually increasing the cross-sectional area, it reduces the airflow velocity and converts dynamic pressure (kinetic energy) into static pressure (potential energy). The volute 200 has a connected receiving cavity 210 and an air outlet cavity 220. The impeller 100 is located in the receiving cavity 210, and the airflow thrown out by the impeller 100 is blown out of the volute 200 through the air outlet cavity 220. The radial baffle 300 is located in the air outlet cavity 220 and divides the air outlet cavity 220 into an inner cavity 221 facing the impeller 100 and an outer cavity 222 facing away from the impeller 100.

[0044] Based on the above design, the volute 200 has a connected receiving cavity 210 and an air outlet cavity 220. The impeller 100 is located in the receiving cavity 210. Airflow can enter the impeller 100 from the side of the fixed ring 120 along the axial direction of the rotating shaft 140, and then be thrown out from the side of the blades 130 (impeller 100), entering the air outlet cavity 220 from the receiving cavity 210. The radial baffle 300 is located in the air outlet cavity 220, dividing the air outlet cavity 220 into an inner cavity 221 facing the impeller 100 and an outer cavity 222 away from the impeller 100. Thus, the airflow in the air outlet cavity 220 is divided into two airflows by the radial baffle 300, which enter the inner cavity 221 and the outer cavity 222 respectively, and then blow out of the volute 200. On the one hand, the radial baffle 300 plays a role in guiding and splitting the flow, improving the internal flow field of the volute 200, that is, confining the vortices generated in the volute 200 to the inner cavity 221. Figure 8Within the dashed box (in the image), the influence range is limited, making the airflow distribution in the outer cavity 222 of the volute 200 more uniform. This reduces the loss caused by the mixing of the two airflows in the inner cavity 221 and the outer cavity 222, thereby improving the performance of the multi-blade centrifugal fan. On the other hand, the radial baffle 300 inside the volute 200 can reduce the noise generated during the operation of the multi-blade centrifugal fan and can also block some of the noise from propagating outward, thereby achieving the effect of noise reduction.

[0045] Figure 3 The diagram shows the airflow domains within the impeller 100 and the volute 200. Here, the airflow entering the inner cavity 221 is referred to as the first airflow 10, and the airflow entering the outer cavity 222 is referred to as the second airflow 20.

[0046] It should be noted that the working principle of the multi-blade centrifugal fan and the flow field distribution principle inside the volute 200 of the multi-blade centrifugal fan are existing technologies in the field and will not be described in detail here. The specific installation method of the blades 130 and the installation method of the impeller 100 and the volute 200 are also existing technologies in the field and will not be described in detail here.

[0047] Optionally, continue as follows Figure 5 and Figure 6 As shown, along the axial direction of the rotating shaft 140, the distance from the side surface of the turntable 110 facing the fixed ring 120 to the fixed ring 120 is the first distance. The value of the first distance gradually increases along the radial direction of the turntable 110 from the rotating shaft 140 to the outer peripheral edge of the turntable 110. That is, the side surface of the turntable 110 facing the fixed ring 120 protrudes towards the fixed ring 120, which facilitates the rapid diffusion of the airflow entering along the axial direction of the rotating shaft 140 to the blades 130 at the outer peripheral edge of the turntable 110.

[0048] Furthermore, the distance from the side surface of the turntable 110 away from the fixed ring 120 to the fixed ring 120 is the second distance. The value of the second distance gradually increases along the radial direction of the turntable 110 from the rotating shaft 140 to the outer peripheral edge of the turntable 110, that is, the side surface of the turntable 110 away from the fixed ring 120 is concave towards the fixed ring 120.

[0049] In this embodiment, the two sides of the turntable 110 along the axial direction of the rotating shaft 140 have the same shape, which improves the thickness uniformity of the turntable 110 in the circumferential direction, facilitates the rotation of the turntable 110, and thus improves the performance of the impeller 100.

[0050] Optionally, the rotating shaft 140, the turntable 110 and the fixing ring 120 are all coaxially arranged, and multiple blades 130 are evenly distributed along the outer circumference of the turntable 110 to further improve the uniformity and stability of the airflow inside the volute 200.

[0051] In this embodiment, the rotating shaft 140 is cylindrical, the cross-section of the turntable 110 (perpendicular to the rotating shaft 140) is circular, the fixing ring 120 is circular, the cross-section of the turntable 110 and the fixing ring 120 have the same radius, and the blade 130 is set perpendicular to the cross-section of the turntable and the fixing ring 120.

[0052] Furthermore, the radial diaphragm 300 extends from the starting point 310 toward the outlet direction of the volute 200 to the ending point.

[0053] In some embodiments, the endpoint of the radial baffle 300 is located inside the air outlet cavity 220 and spaced apart from the outlet of the volute 200, meaning the radial baffle 300 does not reach the outlet of the volute 200. In other embodiments, the endpoint of the radial baffle 300 is located at the outlet of the volute 200, i.e., flush with the outlet of the volute 200, making the airflow velocity at the outlet of the volute 200 more uniform and reducing pipeline losses in the subsequent pipeline network. Of course, in yet another embodiment, the endpoint of the radial baffle 300 can be located outside the volute 200, i.e., the endpoint of the radial baffle 300 extends beyond the outlet of the volute 200.

[0054] When the radial baffle 300 is actually set, the conditions for the starting point 310 to be met are as follows: Figure 4 and Figure 7 As shown, on the cross-section of the volute 200 perpendicular to the rotating shaft 140, the center point of the rotating shaft 140 is point O, and the location of the volute tongue 230 of the volute 200 is point A. Using the distance OA between point O and point A as the radius, the blade 130 is rotated counterclockwise by a preset angle α to reach point B. The extension of the line connecting point O and point B intersects the volute 200 at point C. The starting point 310 is located between points B and C, and 150°≤α≤270°. For example, α can be 150°, 180°, 210°, 230°, 250°, or 270°, etc. That is, the arc angle between the volute tongue 230 and the starting point 310 is the preset angle α.

[0055] It should be noted that the starting point 310 can coincide with point B, but not with point C. If it coincides with point C, the airflow will not be able to enter the outer cavity 222.

[0056] In this embodiment, α = 210°. Of course, in other embodiments, α can be other angles, depending on the required airflow.

[0057] It should be noted that the volute tongue 230 is a key structural component in the volute fan. It is usually located near the outlet of the volute 200 and is tongue-shaped, hence the name volute tongue 230. The specific location design is existing technology in this field and will not be described in detail here.

[0058] In some embodiments, the radial baffle 300 has the same spiral profile as the volute 200, meaning that the cross-section of the outer cavity 222 is of uniform cross-section along the airflow direction in the outlet cavity 220, thus allowing the second airflow 20 within the outer cavity 222 to flow out with a uniform cross-section. Of course, in other embodiments, the radial baffle 300 can be adjusted according to the actual flow conditions. For example, the cross-section of the outer cavity 222 may be gradually narrowing along the airflow direction in the outlet cavity 220; or, the cross-section of the outer cavity 222 may be gradually expanding along the airflow direction in the outlet cavity 220; or, the cross-section of the outer cavity 222 may first expand and then narrow along the airflow direction in the outlet cavity 220; or, the cross-section of the outer cavity 222 may first narrow and then expand along the airflow direction in the outlet cavity 220.

[0059] Along the airflow direction in the air outlet cavity 220, the ratio of the radial width of the outer cavity 222 to the radial width of the air outlet cavity 220 ranges from 0 to 0.9. For example, it can be 0.1, 0.3, 0.6, or 0.8. In this embodiment, the cross-section of the outer cavity 222 is of uniform cross-section shape, and the ratio of the radial width of the outer cavity 222 at the end of the radial baffle 300 to the radial width of the air outlet cavity is 0.5. That is, the end of the radial baffle 300 is located in the middle of the outlet of the volute 200, which roughly evenly distributes the airflow at the outlet of the volute 200.

[0060] Optionally, the radial partition 300 is integrally formed with the volute 200.

[0061] Furthermore, both ends of the radial partition 300 along the axial direction of the rotating shaft 140 abut against the inner wall of the volute 200 to prevent the airflow (first airflow 10) in the inner cavity 221 and the airflow (second airflow 20) in the outer cavity 222 from passing through the gap and mixing with each other, thus affecting the isolation effect of the radial partition 300.

[0062] In some embodiments, the surface of the radial partition 300 may be arranged parallel to the rotating shaft 140. In other embodiments, the surface of the radial partition 300 may also be arranged at an angle to the rotating shaft 140.

[0063] Optionally, the number of radial baffles 300 can be multiple. These radial baffles 300 are spaced apart along a direction perpendicular to the airflow direction to divide the air outlet cavity 220. For example, the number of radial baffles 300 can be two, three, or four, dividing the air outlet cavity 220 into three, four, or five chambers. For ease of understanding, assume there are three radial baffles 300, named the first radial baffle, the second radial baffle, and the third radial baffle, respectively. The first radial baffle divides the air outlet cavity 220 into an inner cavity 221 and an outer cavity 222; the second radial baffle is located within the inner cavity 221 and further divides the inner cavity 221 into two chambers; the third radial baffle is located within the outer cavity 222 and further divides the outer cavity 222 into two chambers, resulting in a total of four chambers. Therefore, the airflow in the outlet chamber 220 is divided into multiple airflows by multiple radial baffles 300, which enter each chamber separately and are then blown out of the volute 200, further reducing the aerodynamic noise generated during the operation of the multi-blade centrifugal fan. It can also further block some of the noise from propagating outward, thereby achieving the effect of noise reduction.

[0064] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A multi-blade centrifugal fan, characterized in that, include: An impeller (100) includes a turntable (110), a fixing ring (120), and a plurality of blades (130). The turntable (110) is sleeved on a rotating shaft (140). The plurality of blades (130) are distributed at intervals along the outer circumference of the turntable (110). The fixing ring (120) and the turntable (110) are arranged opposite to each other to fix the blades (130) at both ends along the axial direction of the rotating shaft (140). A volute (200) is provided with a communicating receiving cavity (210) and an air outlet cavity (220) inside the volute (200), and the impeller (100) is located in the receiving cavity (210); A radial baffle (300) is located in the air outlet cavity (220) and divides the air outlet cavity (220) into an inner cavity (221) facing the impeller (100) and an outer cavity (222) facing away from the impeller (100).

2. The multi-blade centrifugal fan according to claim 1, characterized in that, The rotating shaft (140), the turntable (110) and the fixing ring (120) are all coaxially arranged, and the multiple blades (130) are evenly distributed along the outer circumference of the turntable (110).

3. The multi-blade centrifugal fan according to claim 2, characterized in that, The radial baffle (300) extends from the starting point (310) toward the outlet of the volute (200) to the ending point, the ending point being beyond the outlet of the volute (200); or, the ending point being flush with the outlet of the volute (200); or, the ending point being located within the air outlet cavity (220) and spaced apart from the outlet of the volute (200).

4. The multi-blade centrifugal fan according to claim 3, characterized in that, On the cross-section of the volute (200) perpendicular to the rotating shaft (140), the center point of the rotating shaft (140) is point O, and the location of the volute tongue (230) of the volute (200) is point A. With the distance OA between point O and point A as the radius, the blade (130) is rotated by a preset angle α along the rotation direction to reach point B. The extension line of the line connecting point O and point B intersects the volute (200) at point C. The starting point (310) is located between point B and point C, and 150°≤α≤270°.

5. The multi-blade centrifugal fan according to claim 4, characterized in that, Along the airflow direction in the air outlet cavity (220), the cross-section of the outer cavity (222) is of uniform cross-sectional shape; or, Along the airflow direction in the air outlet cavity (220), the cross-section of the outer cavity (222) is gradually narrowing; or, Along the airflow direction in the air outlet cavity (220), the cross-section of the outer cavity (222) gradually expands; or, Along the airflow direction in the air outlet cavity (220), the cross-section of the outer cavity (222) has an expanding-then-contracting shape; or, Along the airflow direction in the air outlet cavity (220), the cross-section of the outer cavity (222) is in the form of first narrowing and then expanding.

6. The multi-blade centrifugal fan according to claim 5, characterized in that, Along the airflow direction in the air outlet cavity (220), the ratio of the radial width of the outer cavity (222) to the radial width of the air outlet cavity (220) ranges from 0 to 0.

9.

7. The multi-blade centrifugal fan according to claim 5, characterized in that, The radial partition (300) abuts against the inner wall of the volute (200) at both ends along the axial direction of the rotating shaft (140).

8. The multi-blade centrifugal fan according to claim 5, characterized in that, The surface of the radial partition (300) is arranged parallel to the rotating shaft (140); or, the surface of the radial partition (300) is arranged obliquely to the rotating shaft (140).

9. The multi-blade centrifugal fan according to claim 1, characterized in that, Along the axial direction of the rotating shaft (140), the distance from the side surface of the turntable (110) facing the fixed ring (120) to the fixed ring (120) is a first distance, and the value of the first distance gradually increases along the radial direction of the turntable (110) from the rotating shaft (140) to the outer peripheral edge of the turntable (110).

10. The multi-blade centrifugal fan according to claim 1, characterized in that, The radial baffles (300) are multiple in number and are spaced apart along a direction perpendicular to the airflow direction to separate the air outlet cavity (220).

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