Air inlet deflector and fan system

Abstract

The invention discloses an air inlet fluid director and a fan system. The air inlet fluid director is used for being matched with a fan. The air inlet fluid director comprises a fixing part and blades. A plurality of blades are circumferentially arranged at intervals on the fixed part, one end of each blade close to the fixed part forms a root, and one end of each blade far away from the fixed part forms an outer edge. Wherein the air inlet fluid director is provided with a reference axis corresponding to the rotating axis of the fan; in the direction of the reference axis, the blade is provided with a tail edge close to the fan, in the circumferential direction of the air inlet fluid director, the tangential direction of the tail edge of the blade corresponds to the air inlet direction of the fan, and an obtuse angle is formed between the tangential direction of the tail edge of the blade and the rotating direction of the position, corresponding to the blade, of the wind wheel in the fan; the included angle formed by the tangent line of the trailing edge of the root part and the reference axis is larger than the included angle formed by the tangent line of the trailing edge of the outer edge and the reference axis. In this way, airflow can be rectified, and therefore the power capability of the draught fan is improved.

Description

Technical Field

[0001] This application relates to the field of wind turbines, and in particular to air intake guides and wind turbine systems. Background Technology

[0002] In electrical appliances such as air conditioners and refrigerators, fans are typically used to drive airflow to achieve various functions. Airflow entering the fan from the outside usually follows the rotation axis of the impeller. In related technologies, airflow can be deflected by setting up an air intake deflector; however, because the airflow direction does not match the impeller's rotation direction, the impeller's ability to perform work on the airflow is relatively poor. Summary of the Invention

[0003] Embodiments of this application provide an air intake guide and a fan system capable of rectifying airflow, thereby improving the working capacity of the fan.

[0004] This application provides an air intake guide. The air intake guide is used in conjunction with a fan. The air intake guide includes a fixed part and blades. A plurality of blades are arranged circumferentially at intervals on the fixed part, with the end of the blade near the fixed part forming a root and the end of the blade away from the fixed part forming an outer edge. The air intake guide has a reference axis corresponding to the rotation axis of the fan; in the direction of the reference axis, the blades have a trailing edge near the fan; circumferentially, the tangent direction at the trailing edge of the blade corresponds to the air intake direction of the fan, and the tangent direction at the trailing edge of the blade forms an obtuse angle with the rotation direction of the impeller and the corresponding blade in the fan; the angle formed by the tangent at the trailing edge of the root and the reference axis is greater than the angle formed by the tangent at the trailing edge of the outer edge and the reference axis.

[0005] Optionally, from the root to the outer edge, the angle between the tangent direction at the trailing edge of the leaf and the reference axis gradually decreases uniformly.

[0006] Optionally, the angle between the tangent at the tail edge of the root and the reference axis is between 20 and 30 degrees, and the angle between the tangent at the tail edge of the outer edge and the reference axis is between 0 and 15 degrees.

[0007] Optionally, the difference between the angle formed by the tangent at the tail edge of the root and the reference axis and the angle formed by the tangent at the tail edge of the outer edge and the reference axis is between 15 degrees and 20 degrees.

[0008] Optionally, the density of the intake diffuser at the radius corresponding to the root is between 0.8 and 1.5.

[0009] Optionally, the density of the intake diffuser at the corresponding radius on the outer edge is between 0.2 and 0.4.

[0010] Optionally, the number of blades can be between 5 and 17.

[0011] Optionally, the angle between the line connecting the tail edge of the root to the axis of rotation and the line connecting the tail edge of the outer edge to the axis of rotation is the envelope angle, which is between 0 degrees and 40 degrees.

[0012] This application provides a fan system. The fan system includes a fan and the aforementioned air inlet deflector. The air inlet deflector is located upstream of the fan and is configured to deflect the airflow in the opposite direction to the rotation of the impeller in the fan.

[0013] The thickness of the air intake guide is L, and the shortest distance between the impeller and the air intake guide on the rotation axis of the fan is between 0.4L and 0.6L.

[0014] The beneficial effects of this application are as follows: Unlike existing technologies, the embodiments of this application, by setting the tangent direction at the trailing edge of the blades in the circumferential direction of the air inlet guide vane to correspond to the air inlet direction of the fan, and setting the tangent direction at the trailing edge of the blades to an obtuse angle with the rotation direction of the impeller and the corresponding blade in the fan, can pre-swirl the airflow. Since the airflow deflected in the above manner has a component opposite to the rotation direction of the impeller, this method can be called negative pre-swirl. Through this method, the airflow can be negatively pre-swirled at a suitable angle, thereby matching the airflow direction with the rotation direction of the impeller, thus improving the impeller's work capacity on the airflow. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of an embodiment of the fan system of this application; Figure 2 This is a schematic diagram of the structure of an embodiment of the air intake guide of this application; Figure 3 yes Figure 2 A schematic diagram of the root cross-section of the blades of the intake guide vane shown; Figure 4 yes Figure 2 A schematic diagram of the middle section of the blades of the intake guide vane shown; Figure 5 yes Figure 2 A schematic diagram of the outer edge cross-section of the blades of the intake guide vane shown; Figure 6 This is a schematic diagram showing insufficient pre-swirl angle of the airflow for a wind turbine; Figure 7 This is a schematic diagram of the pre-swirl airflow and the wind turbine in this application; Figure 8 This is a schematic diagram showing that the pre-swirl angle of the airflow is too large for the wind turbine; Figure 9 This is a schematic diagram of the envelope angle of an embodiment of the air intake guide in this application; Figure 10 This is a curve showing the relationship between noise and airflow of the air intake guide of this application compared to related technologies; Figure 11 This is a curve showing the relationship between the power and airflow of the air intake guide in this application compared to related technologies. Detailed Implementation

[0016] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are only for explaining this application and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, not all structures. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0017] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, 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, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0018] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0019] In this application, unless otherwise expressly 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 being 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 being 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.

[0020] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0021] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0022] Combination Figure 1This application provides a fan system 1. The fan system 1 includes a fan 20 and an air inlet guide vane 10. The air inlet guide vane 10 is located upstream of the fan 20. Airflow from upstream or the atmosphere may contain irregularities; the air inlet guide vane 10 can rectify the airflow to reduce impact on the fan 20 and reduce uneven loads on the fan 20. Furthermore, the air inlet guide vane 10 can also generate a velocity component in the circumferential direction of the airflow entering the fan 20 by setting the installation angle of the blades 12. In the embodiments of this application, the air inlet guide vane 10 is configured to deflect the airflow in the opposite direction to the rotation direction of the impeller 21 in the fan 20. In other words, the air inlet guide vane 10 of this application adopts a negative pre-swirl technique, that is, the air inlet guide vane 10 can deflect the airflow, generating a velocity component in the circumferential direction opposite to the rotation direction of the impeller 21. Negative pre-swirl can significantly improve the work capacity of the impeller 21 under the same conditions, which is beneficial for increasing aerodynamic efficiency and increasing air volume.

[0023] In some embodiments, the thickness of the air intake guide 10 is L, and the shortest distance between the impeller 21 and the air intake guide 10 on the rotation axis of the fan 20 is between 0.4L and 0.6L. If this size is too small, it can easily cause interference between the rotation of the impeller 21 and the air intake guide 10. If this size is too large, the rectified airflow of the air intake guide 10 will have to travel a longer path before being pushed by the impeller 21, resulting in a decrease in actual performance. Optionally, the extension direction of the blades 12 in the air intake guide 10 can be perpendicular to the rotation axis of the impeller 21. Optionally, the extension direction of the blades 12 in the air intake guide 10 can be inclined, specifically, the blades 12 can be inclined away from the impeller 21 in a direction radially away from the rotation center of the impeller 21.

[0024] Combination Figure 2 This application provides an air intake guide 10. The air intake guide 10 is used in conjunction with a fan 20. The air intake guide 10 includes a fixing part 11 and blades 12. The fixing part 11 can fix the blades 12, and the end of the fixing part 11 near the upstream can be tapered to guide the airflow. A plurality of blades 12 are arranged circumferentially at intervals on the fixing part 11, with the end of the blade 12 near the fixing part 11 forming a root and the end of the blade 12 away from the fixing part 11 forming an outer edge.

[0025] Combination Figure 3The inlet guide vane 10 has a reference axis corresponding to the rotation axis of the fan 20. In the direction of the reference axis, the blade 12 has a trailing edge close to the fan 20. In the circumferential direction of the inlet guide vane 10, the tangent direction at the trailing edge of the blade 12 corresponds to the air intake direction of the fan 20. Specifically, the angle formed between the tangent of the trailing edge of the blade 12 on the side close to the impeller 21 and the rotation axis is greater than the angle formed between the side of the blade 12 away from the impeller 21 and the rotation axis. This allows the airflow to be gradually radially guided and deflected by the blade 12 as it blows towards it, thus generating a circumferential component. The direction of the tangent at the trailing edge of the blade 12 reflects the direction that deflects the airflow, and this direction corresponds to the air intake direction. In other words, the tangent direction at the trailing edge of the blade 12 all have a component pointing towards the impeller 21.

[0026] In this embodiment, the tangential direction at the trailing edge of the blade 12 is set at an obtuse angle to the rotation direction of the impeller 21 and the corresponding blade 12 in the fan 20. That is, the tangential direction at the trailing edge of the blade 12 has an airflow in the circumferential direction opposite to the rotation direction of the impeller 21, and the blade 12 can generate a negative pre-swirl effect on the airflow.

[0027] Combination Figures 2 to 5 In the diagram, A1 is the base of leaf 12, A2 is the middle of the leaf, and A3 is the outer edge of the leaf. Figures 3 to 5 The shapes of the blades at points A1, A2, and A3 are shown respectively. θ in the figure represents the angle between the tangent at the trailing edge and the reference axis. Specifically, the angle between the tangent at the trailing edge of the root of blade 12 and the reference axis is greater than the angle between the tangent at the trailing edge of the outer edge and the reference axis. The airflow can be pre-swirled by the inlet guide 10. Since the airflow deflected in this manner has a component opposite to the rotation direction of the impeller 21, this method can be called negative pre-swirl. Through this method, the airflow can be negatively pre-swirled by a suitable angle, thereby matching the airflow direction with the rotation direction of the impeller 21, thus improving the work capacity of the impeller 21.

[0028] In some embodiments, from the root to the outer edge, the angle between the tangent direction of the blade 12 at its trailing edge and the reference axis gradually decreases uniformly. In this way, the pre-swirl angle of the airflow gradually decreases in the direction of increasing radius. The installation angle of the impeller 21 generally decreases gradually from the blade root to the blade tip. By setting the angle between the tangent direction of the trailing edge of the blade 12 and the rotation axis to gradually decrease, the direction of airflow deflection can be matched with the distribution of the impeller 21's installation angle. This ensures that the angle between different radial sections of the impeller 21 and the direction of the pre-swirled airflow is essentially consistent, thereby optimizing the airflow direction distribution in the radial direction of the impeller 21 and improving the work capacity of the impeller 21.

[0029] Combination Figures 6 to 8The figure shows the relationship between blade 12 and the direction of the airflow after deflection. Figure 6 This illustrates the case of insufficient pre-spin angle. Figure 7 This illustrates the case where the pre-spin angle is appropriate. Figure 8 The diagram illustrates a case where the pre-spin angle is too large. In some embodiments, the angle between the tangent at the trailing edge of the root and the reference axis is between 20 and 30 degrees, for example, 22, 25, or 27 degrees. The angle between the tangent at the trailing edge of the outer edge and the reference axis is between 0 and 15 degrees, for example, 3, 5, or 7 degrees. Wherein, combined with... Figure 8 If the negative pre-spin angle is too large, it will cause new separation flow after the airflow blows towards the impeller 21, which will lead to a decrease in the work capacity of the impeller 21. Figure 6 If the negative pre-swirl angle is too small, the airflow direction will not be properly matched with the rotor 21, failing to increase the rotor 21's work capacity. A large negative pre-swirl angle will also cause the blade 12 to stall easily, leading to increased drag. A small negative pre-swirl angle will result in insufficient load on the rotor 21, making it unable to effectively drive the airflow.

[0030] In some embodiments, the difference between the angle formed by the tangent at the trailing edge of the blade root and the reference axis and the angle formed by the tangent at the trailing edge of the outer edge and the reference axis is between 15 and 20 degrees. The angle formed by the tangent at the trailing edge of the blade 12 and the reference axis gradually decreases from its root to its outer edge. The difference between the angle formed by the tangent at the trailing edge of the blade root and the reference axis and the angle formed by the tangent at the trailing edge of the outer edge and the reference axis needs to be sufficient. If the difference is too large or too small, the direction of airflow deflection will not be suitable for the impeller 21, resulting in only localized airflow matching with the impeller 21, failing to achieve a significant effect.

[0031] In some embodiments, the density of the blades 12 at the root radius of the intake deflector 10 is between 0.8 and 1.5, for example, 1 or 1.2. The density of the blades 12 at the outer edge radius of the intake deflector 10 is between 0.2 and 0.4, for example, 0.3. The density of the blades 12 refers to the ratio of the actual distance between the blades 12 at the selected radius to the arc distance between two adjacent blades 12. The density of the blades 12 is also one of the important parameters affecting airflow guidance. Lower density weakens the actual negative pre-rotation angle of the airflow, that is, there is an angle difference between the actual deflection angle of the airflow after passing through the blades 12 and the negative pre-rotation angle set by the blades 12, and this angle difference is inversely proportional to the density. On the other hand, higher density increases the blockage of the inlet, leading to an increase in noise sources (e.g., by increasing the number of blades 12 to increase density) or leading to a larger axial space occupation (by increasing the chord length to increase density), both of which are not conducive to improving efficiency and reducing noise.

[0032] In some embodiments, the number of blades 12 is between 5 and 17, such as 7, 10, 12, or 14. A smaller number of blades 12 results in insufficient deflection of the airflow, failing to achieve the desired effect. A larger number of blades 12 increases intake resistance, hindering work capacity and generating noise. On the other hand, in this application, the multiple blades 12 are arranged radially. Besides deflecting the airflow, the blades 12 also serve to connect to the external support and support the fixing part 11. Too few blades 12 reduce the strength of the intake guide 10, making the blades prone to unintended bending.

[0033] In some embodiments, combined with Figure 9 The angle between the line connecting the trailing edge of the root to the axis of rotation and the line connecting the trailing edge of the outer edge to the axis of rotation is the envelope angle (in conjunction with...). Figure 9 The envelope angle (α) is between 0 and 40 degrees. If the envelope angle is too large, the airflow on the surface of blade 12 will be more prone to flow separation, which will reduce the stable operating range of the fan 20 and make it prone to stall.

[0034] The blade shape of the blade 12 in this embodiment can be either a conventional airfoil or an equal-thickness blade, and there is no specific limitation.

[0035] In summary, referring to the table below, IGV-25°-5°-B11 in the table refers to the negative pre-rotation angle of blade 12 decreasing from 25 degrees to 5 degrees from the root to the outer edge, and the number of blades 12 being 11. Other descriptions are similar and will not be repeated. Compared to related technologies that do not employ the inlet guide vane 10, this embodiment of the application, at the same rotational speed, effectively increases the airflow by increasing power. Static pressure efficiency is effectively improved, and the total sound power is significantly reduced.

[0036]

[0037] Further integration Figure 10 and Figure 11 The air intake guide 10 in this embodiment of the application, compared to the case where the air intake guide 10 is not provided in the related art, has lower noise under the same air volume. Furthermore, it can generate a higher air volume under the same power.

[0038] The above are merely embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. An air intake guide for use with a fan, characterized in that, include: Fixing part; The blades are arranged circumferentially at intervals on the fixing part, with the blades forming a root at the end near the fixing part and an outer edge at the end away from the fixing part; The air intake guide has a reference axis corresponding to the rotation axis of the fan; in the direction of the reference axis, the blade has a trailing edge close to the fan; in the circumferential direction of the air intake guide, the tangent direction at the trailing edge of the blade corresponds to the air intake direction of the fan; the tangent direction at the trailing edge of the blade is set at an obtuse angle to the rotation direction of the impeller and the corresponding blade in the fan; the angle formed by the tangent at the trailing edge of the root and the reference axis is greater than the angle formed by the tangent at the trailing edge of the outer edge and the reference axis.

2. The air intake guide according to claim 1, characterized in that: From the root to the outer edge, the angle between the tangent direction of the blade at the trailing edge and the reference axis gradually and uniformly decreases.

3. The air intake guide according to claim 2, characterized in that: The angle between the tangent at the tail edge of the root and the reference axis is between 20 and 30 degrees, and the angle between the tangent at the tail edge of the outer edge and the reference axis is between 0 and 15 degrees.

4. The air intake guide according to claim 3, characterized in that: The difference between the angle formed by the tangent at the tail edge of the root and the reference axis and the angle formed by the tangent at the tail edge of the outer edge and the reference axis is between 15 degrees and 20 degrees.

5. The intake guide according to claim 1, characterized in that: The air intake deflector has a blade density between 0.8 and 1.5 at the radius corresponding to the root.

6. The intake guide according to claim 1, characterized in that: The density of the blades of the air intake deflector at the radius corresponding to the outer edge is between 0.2 and 0.

4.

7. The intake guide according to claim 1, characterized in that: The number of blades is between 5 and 17.

8. The intake guide according to claim 1, characterized in that: The angle between the line connecting the tail edge of the root to the axis of rotation and the line connecting the tail edge of the outer edge to the axis of rotation is the envelope angle, which is between 0 degrees and 40 degrees.

9. A fan system, characterized in that: Fan; The intake deflector as described in any one of claims 1-8; The air intake deflector is located upstream of the fan, and the air intake deflector is configured to deflect the airflow in the opposite direction to the rotation direction of the impeller in the fan.

10. The fan system 1 according to claim 9, characterized in that: The thickness of the air intake guide is L, and the shortest distance between the impeller and the air intake guide on the rotation axis of the fan is between 0.4L and 0.6L.

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