A guide vane assembly, an axial flow fan and a control method

Abstract

The application provides a guide vane assembly, an axial flow fan and a control method, wherein the guide vane assembly comprises a hub, a guide vane blade group and an outer ring, the hub is located on the inner side of the outer ring; the guide vane blade group has a first section and a second section connected in sequence along the axial direction of the hub, the guide vane blade group is connected with the hub through one end of the first section in the radial direction, and is connected with the outer ring through the other end of the first section in the radial direction; the second section can be telescoped relative to the first section along the axial direction of the hub to adjust the axial height of the guide vane blade group. According to the technical scheme of the application, the telescoping amount of the second section can be adjusted according to the optimal axial height of the guide vane blade group under different static pressure conditions, so that the guide vane blade group is adjusted to the optimal axial height, and the axial flow fan has the optimal aerodynamic performance.

Description

Technical Field

[0001] This invention belongs to the field of axial flow fan technology, specifically relating to a guide vane assembly, an axial flow fan, and a control method. Background Technology

[0002] Axial flow fans are characterized by high flow rate and high efficiency, and are widely used in various ventilation systems. However, axial flow fans have relatively low static pressure. When the system resistance increases, the outlet airflow direction of the axial flow fan presents a large angle along the axial direction, and even backflow occurs near the blade root, causing a sharp decline in the aerodynamic performance of the axial flow fan. In this case, adding guide vanes downstream of the fan blades in the airflow direction can significantly improve this situation, where the axial height of the guide vanes remains constant.

[0003] Guide vanes have functions such as recovering the outlet kinetic energy of axial flow fans, improving the outlet airflow structure of axial flow fans, and enhancing the ability of axial flow fans to overcome static pressure. Among these functions, the aerodynamic performance of axial flow fans will change under different static pressure conditions, and ensuring that axial flow fans have optimal aerodynamic performance under different static pressure conditions is a problem that those skilled in the art need to solve. Summary of the Invention

[0004] Therefore, the present invention provides a guide vane assembly, an axial flow fan, and a control method. The main technical problem to be solved is: how to enable the axial flow fan to have better aerodynamic performance under different static pressure conditions.

[0005] To address the aforementioned problems, the present invention provides a guide vane assembly, which includes a hub, a guide vane blade assembly, and an outer ring, wherein the hub is located inside the outer ring;

[0006] The guide vane assembly has a first section and a second section connected sequentially along the axial direction of the hub. The guide vane assembly is connected to the hub through one radial end of the first section and to the outer ring through the other radial end of the first section. The second section can extend and retract relative to the first section along the axial direction of the hub to adjust the axial height of the guide vane assembly.

[0007] In some embodiments, the first segment and the second segment are inserted into each other along the axial direction of the hub, so that the second segment can extend or retract relative to the first segment along the axial direction of the hub.

[0008] In some embodiments, the hub has a first hub segment and a second hub segment connected sequentially along the axial direction, the first hub segment and the second hub segment being inserted into each other along the axial direction of the hub; the hub is connected to one radial end of the first hub segment through the first hub segment;

[0009] The end of the second segment that is away from the outer ring is connected to the second hub segment.

[0010] In some embodiments, the guide vane assembly further includes a drive mechanism for driving the second section to extend or retract relative to the first section along the axial direction of the hub.

[0011] In some embodiments, the driving mechanism includes an electromagnet, an elastic element, and a magnetic attractor, one of which is disposed on the first segment and the other on the second segment; the electromagnet is used to attract the magnetic attractor to drive the second segment to retract relative to the first segment along the axial direction of the hub; the elastic element is used to drive the second segment to extend relative to the first segment along the axial direction of the hub.

[0012] In some embodiments, when the wheel hub has a first hub segment and a second hub segment connected sequentially along the axial direction,

[0013] One of the electromagnet and the magnetic attractor is disposed on the first hub section to connect with the first segment via the first hub section; the other of the electromagnet and the magnetic attractor is disposed on the second hub section to connect with the second segment via the second hub section.

[0014] In some embodiments, the axial height of the guide vane blade assembly is H, and the outer diameter is D, wherein H is greater than or equal to 0.08 * D.

[0015] In some implementations, H = a * D, 0.08 ≤ a ≤ 1.

[0016] In some embodiments, the first segment has a first sub-segment and a second sub-segment connected sequentially along the axial direction, and the first segment is connected to the second segment through the second sub-segment; wherein, the second sub-segment and the second segment are both straight segments extending along the axial direction of the hub, and the portion of each guide vane in the guide vane blade group located in the first sub-segment is the first blade portion;

[0017] Each of the first blade sections is twisted circumferentially along the hub, and the exit geometry angle of each first blade section is 90 degrees. The inlet geometry angle α of each first blade section at different positions in the radial direction of the hub satisfies: α=tan -1 (v z / v T ), v z v is the axial velocity of the airflow. T The circumferential velocity of the airflow; and / or, each of the first blade portions is bent radially along the hub at an angle of 50°-70°.

[0018] In some embodiments, the outer ring has an arc-shaped diffuser section on the air outlet side.

[0019] The present invention also provides an axial flow fan, which may include the guide vane assembly described in any one of the above.

[0020] In some embodiments, the axial flow fan further includes fan blades; the guide vane assembly is located downstream of the fan blades in the air outlet direction.

[0021] The number of guide vanes in the guide vane blade group is not an integer multiple of the number of wind turbine blades.

[0022] The present invention also provides a control method for the above-mentioned axial flow fan. When the axial flow fan includes a drive mechanism, and the drive mechanism includes an electromagnet, an elastic element, and a magnetic attracting element, one of the electromagnet and the magnetic attracting element is disposed on the first segment, and the other is disposed on the second segment; the electromagnet is used to attract the magnetic attracting element to drive the second segment to retract relative to the first segment along the axial direction of the hub; the elastic element is used to drive the second segment to extend relative to the first segment along the axial direction of the hub, the control method includes the following steps:

[0023] Detect the static pressure at the air inlet of the axial flow fan;

[0024] The optimal axial height of the guide vane blade assembly is determined based on the static pressure. Then, the magnetic force of the electromagnet is adjusted to cause the elastic element to extend and retract, driving the second section to move along the axial direction of the hub, thereby adjusting the axial height of the guide vane blade assembly to the optimal axial height.

[0025] The guide vane assembly, axial flow fan, and control method provided by this invention have the following beneficial effects:

[0026] The extension and retraction of the second section can be adjusted according to the optimal axial height of the guide vane blade assembly under different static pressure conditions, so as to adjust the guide vane blade assembly to the optimal axial height and give the axial flow fan the best aerodynamic performance. Attached Figure Description

[0027] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of the guide vane assembly of the present invention when the second section extends relative to the first section;

[0029] Figure 2 This is a schematic diagram of the structure of the second section of the guide vane assembly of the present invention when it is retracted relative to the first section;

[0030] Figure 3 This is a schematic diagram showing the connection between the first sub-segment of the guide vane blade assembly and the first hub segment and outer ring.

[0031] Figure 4 This is a schematic diagram showing the connection between the second sub-segment of the guide vane blade assembly and the first hub segment;

[0032] Figure 5 This is a schematic diagram showing the connection between the second section of the guide vane blade assembly and the second hub section;

[0033] Figure 6 This is a schematic diagram of the structure of an axial flow fan;

[0034] Figure 7 yes Figure 6 Enlarged view of point A in the middle;

[0035] Figure 8 yes Figure 6 Enlarged view of point B in the middle;

[0036] Figure 9 This is an exploded view of an axial flow fan;

[0037] Figure 10 This is a schematic diagram of the wind turbine blades;

[0038] Figure 11 This is a schematic diagram of the air guide ring structure;

[0039] Figure 12 It is a schematic diagram reflecting the bending angle of the first blade and its different radial height positions;

[0040] Figure 13 It is a schematic diagram reflecting the inlet and outlet geometry of the first blade section;

[0041] Figure 14 A flow rate-static pressure curve for an axial flow fan is provided.

[0042] Figure 15 A flow rate-static pressure efficiency curve for an axial flow fan is provided.

[0043] The attached figures are labeled as follows:

[0044] 1. Hub; 2. Outer ring; 3. Guide vane assembly; 4. First limiting component; 5. Second limiting component; 6. Fan blade; 7. Electromagnet; 8. Magnetic component; 9. Guide ring; 10. Elastic component; 11. First hub section; 12. Second hub section; 91. Reinforcing rib; b. Exit geometry angle; c. Bending angle; 31. First section; 32. Second section; 301. First blade section; 302. Second blade section; 303. Third blade section; 311. First sub-section; 312. Second sub-section; 320. Insertion hole; 100. Guide vane assembly; 31a. One radial end of the first section; 31b. The other radial end of the first section. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms 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 on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0047] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0048] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0049] See also Figure 1-8 As shown, according to an embodiment of the present invention, a guide vane assembly 100 is provided, which includes a hub 1, a guide vane blade assembly 3 and an outer ring 2, wherein the hub 1 is located inside the outer ring 2.

[0050] The guide vane blade assembly 3 has a first section 31 and a second section 32 connected sequentially along the axial direction of the hub 1. The guide vane blade assembly 3 has two or more guide vane blades, each guide vane blade having a portion located on the first section 31 and a portion located on the second section 32. Specifically, the portions of each guide vane blade on the first section 31 cooperate to form the first section 31, and the portions of each guide vane blade on the second section 32 cooperate to form the second section 32. In a specific application example, the number of guide vane blades is 13.

[0051] The aforementioned guide vane blade assembly 3 is connected to the hub 1 via one radial end 31a of the first section and to the outer ring 2 via the other radial end 31b of the first section. The aforementioned second section 32 can extend and retract relative to the first section 31 along the axial direction of the hub 1 to adjust the axial height of the guide vane blade assembly 3. Specifically, when the second section 32 retracts relative to the first section 31 along the axial direction of the hub 1, the axial height of the guide vane blade assembly 3 can be reduced; when the second section 32 extends relative to the first section 31 along the axial direction of the hub 1, the axial height of the guide vane blade assembly 3 can be increased.

[0052] In the above example, since the second segment 32 can extend and retract relative to the first segment 31 along the axial direction of the hub 1, the axial height of the guide vane assembly 3 can be adjusted. Experiments have shown that under different static pressure conditions, the guide vane assembly 3 has different optimal axial heights to ensure the axial flow fan has optimal aerodynamic performance. Therefore, the extension and retraction of the second segment 32 can be adjusted according to the optimal axial height of the guide vane assembly 3 under different static pressure conditions to adjust the guide vane assembly 3 to the optimal axial height, thus ensuring the axial flow fan has optimal aerodynamic performance. Table 1 provides a performance parameter table for an axial flow fan. Figure 14 A flow rate-static pressure curve for an axial flow fan is provided. Figure 15 A flow rate-static pressure efficiency curve for an axial flow fan is provided.

[0053] Table 1

[0054]

[0055] like Figure 14 , Figure 15 As shown in Table 1, with a static pressure in the range of 50-80 Pa, compared with axial flow fans without guide vanes or with fixed guide vanes, the axial flow fan of the present invention with an axial height adjustable guide vane assembly 100 can always maintain high flow rate and high efficiency operation, and has excellent aerodynamic performance.

[0056] The optimal axial height range of the guide vane blade assembly 3 of the present invention is applicable to working conditions with static pressure below 80 Pa. When the static pressure increases, the axial height of the guide vane blade assembly 3 needs to be increased.

[0057] The technical solution of this invention significantly improves the aerodynamic performance of the axial flow fan under high static pressure conditions and enhances the compatibility between the fan blades 6 and the guide vane assembly 100. In a specific application example, the axial height of the guide vane blade assembly 3 can be adjusted within the range of 35 mm to 45 mm.

[0058] In some embodiments, the first segment 31 and the second segment 32 are inserted into each other along the axial direction of the hub 1 so that the second segment 32 can extend and retract relative to the first segment 31 along the axial direction of the hub 1.

[0059] In the example above, such as Figure 7 As shown, one of the first segment 31 and the second segment 32 may be provided with a insertion hole 320, and the other segment may be inserted into the insertion hole 320. This allows the first segment 31 and the second segment 32 to be inserted into each other along the axial direction of the hub 1. The insertion hole 320 can guide the insertion of the first segment 31 and the second segment 32, thereby improving the extension and retraction accuracy of the second segment 32.

[0060] In some implementations, such as Figure 8 As shown, the aforementioned hub 1 has a first hub segment 11 and a second hub segment 12 connected sequentially along the axial direction. The first hub segment 11 and the second hub segment 12 are inserted into each other along the axial direction of the hub 1. The hub 1 is connected to the radial end 31a of the aforementioned first segment through the first hub segment 11. The end of the aforementioned second segment 32 facing away from the outer ring 2 is connected to the second hub segment 12. The second segment 32 and the second hub segment 12 form a whole, and the end of the second segment 32 near the outer ring 2 is a free end. The second hub 1 can drive the portion of each guide vane on the second segment 32 to move synchronously, so that each guide vane extends and retracts synchronously.

[0061] In some embodiments, the aforementioned guide vane assembly 100 may further include a drive mechanism for driving the second section 32 to extend and retract relative to the first section 31 along the axial direction of the hub 1. This drive mechanism allows for automated control of the extension and retraction of the second section 32, offering the advantage of saving manpower.

[0062] To achieve the functions of the aforementioned drive mechanism, in some embodiments, such as Figure 6 As shown, the aforementioned driving mechanism may include an electromagnet 7, an elastic element 10, and a magnetic attractor 8. One of the electromagnet 7 and the magnetic attractor 8 is disposed on the first segment 31, and the other is disposed on the second segment 32. The electromagnet 7 is used to attract the magnetic attractor 8, thereby causing the second segment 32 to retract relative to the first segment 31 along the axial direction of the hub 1. The elastic element 10 is used to drive the second segment 32 to extend relative to the first segment 31 along the axial direction of the hub 1.

[0063] The magnetic attraction element 8 mentioned above can be a metal part, etc. The elastic element 10 can be a spring, etc.

[0064] In the above example, when the system wind resistance increases or decreases, the magnetism of the electromagnet 7 can be adjusted to cause the elastic element 10, such as a spring, to extend or retract, thereby driving the second section 32 to extend or retract axially, so as to adjust the axial height of the guide vane assembly 3 to the optimal level, thereby improving the matching between the fan blades 6 and the guide vane assembly 3 of the axial flow fan.

[0065] In some embodiments, when the aforementioned hub 1 has a first hub segment 11 and a second hub segment 12 connected sequentially along the axial direction, one of the electromagnet 7 and the magnetic attractor 8 is disposed on the first hub segment 11 to connect with the first segment 31 via the first hub segment 11. The other of the electromagnet 7 and the magnetic attractor 8 is disposed on the second hub segment 12 to connect with the second segment 32 via the second hub segment 12.

[0066] By respectively arranging the electromagnet 7 and the magnetic attractor 8 on the first hub section 11 and the second hub section 12, interference with the airflow of the guide vane assembly 3 can be avoided. Preferably, one of the electromagnet 7 and the magnetic attractor 8 is located inside the first hub section 11, and the other of the electromagnet 7 and the magnetic attractor 8 is located inside the second hub section 12.

[0067] In some implementations, such as Figure 1 and Figure 2 As shown, the aforementioned drive mechanism may further include a first limiting member 4 and a second limiting member 5. Both the first limiting member 4 and the second limiting member 5 may be rod-shaped, and their center lines coincide, and their center lines are parallel to the axial direction of the hub 1. One of the first limiting member 4 and the second limiting member 5 is disposed on the first hub segment 11, and the other is disposed on the second hub segment 12. When the electromagnet 7 is de-energized, there is a gap between the first limiting member 4 and the second limiting member 5. When the second segment 32 retracts to its limit position relative to the first segment 31, the first limiting member 4 and the second limiting member 5 abut against each other to provide limiting protection and prevent the second segment 32 from over-retracting.

[0068] In some embodiments, one of the aforementioned electromagnet 7 and magnetic attractor 8 can be fixed to the first limiting member 4, and the other can be fixed to the second limiting member 5. Alternatively, one end of the elastic member 10 can be fixed to the first limiting member 4, and the other end of the elastic member 10 can be fixed to the second limiting member 5.

[0069] In some embodiments, the axial height of the aforementioned guide vane blade assembly 3 is H, and the outer diameter of the guide vane blade assembly 3 is D. Wherein, H is greater than or equal to 0.08 * D.

[0070] In the example above, the flow guiding effect can be improved by making H greater than or equal to 0.08*D. Considering the axial dimension limitation, preferably, H = a*D, 0.08 ≤ a ≤ 1.

[0071] In some implementations, such as Figure 1 As shown, the aforementioned first segment 31 has a first sub-segment 311 and a second sub-segment 312 connected sequentially along the axial direction. The first sub-segment 311 and the second sub-segment 312 remain relatively fixed. The first segment 31 is connected to the aforementioned second segment 32 via the second sub-segment 312. Both the second sub-segment 312 and the second segment 32 are straight segments extending along the axial direction of the hub 1, facilitating the sliding of the second segment 32 on the second sub-segment 312 along the axial direction of the hub 1, thereby achieving the purpose of the second segment 32 extending and retracting relative to the first segment 31 along the axial direction of the hub 1.

[0072] like Figure 3 As shown, the portion of each guide vane blade in the aforementioned guide vane blade assembly 3 located in the first sub-segment 311 is the first blade section 301. Each first blade section 301 is twisted circumferentially along the hub 1, and the exit geometry angle b of each first blade section 301 is 90 degrees. The inlet geometry angle α of each first blade section 301 at different radial positions in the hub 1 satisfies: α = tan(tg ... -1 (v z / v T ), v z v is the axial velocity of the airflow. T This represents the circumferential velocity of the airflow.

[0073] In the above example, by setting the inlet geometry angle α = tan of each first blade portion 301 along the axial direction of the hub 1... -1 (v z / v T This ensures that the inlet geometry of the guide vane is consistent with the airflow direction at the fan outlet, reducing speed loss.

[0074] Wherein, according to the above formula α=tg -1 (v z / v TAccording to the principle of equal circulation design, the axial velocity at the fan outlet remains constant along the radial direction, while the circumferential velocity increases radially. Therefore, the larger the radial height of the first blade section 301, the smaller the inlet geometry angle of the first blade section 301. In a specific application example, such as... Figure 12 As shown, the inlet geometric angles of the first blade section 301 at the radial height sections of 0%, 20%, 40%, 60%, and 80% are 49°, 43°, 39°, 37°, and 34°, respectively. That is, as the radial height of the first blade section 301 increases, the inlet geometric angle of the first blade section 301 decreases. This ensures that the inlet geometric angle of the first blade section 301 is consistent with the outlet airflow direction of the fan.

[0075] like Figure 13 As shown, the outlet geometric angle b of each of the aforementioned first blade sections 301 is 90 degrees, that is, each of the first blade sections 301 directs the airflow at the fan outlet along the axial direction, which is beneficial to improving the flow field structure at the fan outlet.

[0076] like Figure 4 and Figure 5 As shown, the portion of each guide vane blade in the aforementioned guide vane blade group 3 located in the second sub-segment 312 is a second blade portion 302, and the portion of each guide vane blade in the aforementioned guide vane blade group 3 located in the second segment 32 is a third blade portion 303. The number of second blade portions 302 and third blade portions 303 are equal, and they are inserted and fitted in a one-to-one correspondence. The inlet geometric angle of each second blade portion 302 is equal to the outlet geometric angle b of each third blade portion 303, ensuring a smooth transition at the connection between the second blade portion 302 and the corresponding third blade portion 303.

[0077] In some implementations, such as Figure 12 As shown, each of the aforementioned first blade sections 301 is bent radially along the hub 1, with a bending angle c of 50°-70°. This allows each first blade section 301 to concentrate the airflow that diffuses outwards into the central region. Furthermore, the design of the outlet geometry angle b of each first blade section 301 being 90 degrees converts the circumferential motion of the airflow into axial motion, thereby significantly improving the aerodynamic performance of the axial flow fan. Preferably, the bending angle c of each first blade section 301 is 65°.

[0078] In some embodiments, the outer ring 2 has an arc-shaped diffuser section on the outlet side, which reduces the vortex generated at the outlet.

[0079] like Figure 6 and Figure 9As shown, the present invention also provides an axial flow fan, which may include the guide vane assembly 100 of any of the above-mentioned components. Because the axial flow fan uses the guide vane assembly 100, the extension and retraction of the second section 32 can be adjusted according to the optimal axial height of the guide vane blade assembly 3 under different static pressure conditions, so as to adjust the guide vane blade assembly 3 to the optimal axial height, thereby giving the axial flow fan optimal aerodynamic performance.

[0080] In some implementations, such as Figure 6 As shown, the aforementioned axial flow fan may further include a fan blade 6. The aforementioned guide vane assembly 100 is located downstream of the fan blade 6 in the air outlet direction. The number of guide vane blades in the guide vane blade assembly 3 is not an integer multiple of the number of blades in the fan blade 6, to avoid generating multi-harmonic vibrations at the blade passage frequency.

[0081] In some implementations, such as Figure 6 and Figure 9 As shown, the aforementioned axial flow fan also includes a guide ring 9, which is nested within the aforementioned outer ring 2. The guide ring 9 and the outer ring 2 can be fixedly connected by bolts. The inner diameter of the outer ring 2 is equal to the inner diameter of the guide ring 9, so that there is no gap at the connection between the inner sides of the outer ring 2 and the guide ring 9. A reinforcing rib 91 may be provided on the outer side of the guide ring 9.

[0082] In this process, air enters the guide ring 9 under the action of the fan blade 6, and flows out along the axial direction after being guided by the guide blade assembly 3.

[0083] The present invention also provides a control method for the above-mentioned axial flow fan. When the axial flow fan includes a drive mechanism, and the drive mechanism includes an electromagnet 7, an elastic element 10, and a magnetic attractor 8, one of the electromagnet 7 and the magnetic attractor 8 is disposed on the first segment 31, and the other is disposed on the second segment 32; the electromagnet 7 is used to attract the magnetic attractor 8 to drive the second segment 32 to retract relative to the first segment 31 along the axial direction of the hub 1; the elastic element 10 is used to drive the second segment 32 to extend relative to the first segment 31 along the axial direction of the hub 1, the above-mentioned control method includes the following steps:

[0084] Step S1: Detect the static pressure at the air inlet of the axial flow fan. Specifically, a sensor can be used to detect the static pressure at the air inlet of the axial flow fan.

[0085] Step S2: Determine the optimal axial height of the guide vane blade assembly 3 based on the above static pressure, and then adjust the magnetic force of the electromagnet 7 to make the elastic element 10 extend and retract, driving the second section 32 to move along the axial direction of the hub 1, so as to adjust the axial height of the guide vane blade assembly 3 to the optimal axial height.

[0086] In step S2 above, the magnetic force of electromagnet 7 can be adjusted by adjusting the current in the electromagnet coil.

[0087] For ease of understanding, the overall structure of the present invention will be described below, and its working principle will be explained.

[0088] The optimal axial height of the guide vane assembly 3 varies under different static pressure conditions. In traditional axial flow fans, the axial height of the guide vane assembly 3 remains constant during operation. Changes in system resistance can reduce the performance enhancement effect of the guide vane assembly 3. However, the axial height of the guide vane assembly 3 in this invention is adjustable. When system resistance increases or decreases, the magnetism of the electromagnet 7 can be adjusted to cause the elastic element 10 to extend or retract, thereby causing the second section 32 to extend or retract axially. This adjusts the axial height of the guide vane assembly 3 to the optimal level, improving the matching between the fan blades 6 and the guide vane assembly 3.

[0089] The present invention can automatically adjust the axial height of the guide vane blade assembly 3. When the sensor detects a change in static pressure at the air inlet of the axial flow fan, the magnetic force of the electromagnet 7 is adjusted to cause the elastic element 10 to extend and retract, driving the second section 32 to move along the axial direction of the hub 1, thereby achieving the purpose of automatically adjusting the axial height of the guide vane blade assembly 3, which can improve the air volume and efficiency of the axial flow fan.

[0090] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0091] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A guide vane assembly, characterized in that: It includes a hub (1), a guide vane assembly (3), and an outer ring (2), wherein the hub (1) is located inside the outer ring (2); The guide vane blade assembly (3) has a first section (31) and a second section (32) connected sequentially along the axial direction of the hub (1). The guide vane blade assembly (3) is connected to the hub (1) through one radial end (31a) of the first section and to the outer ring (2) through the other radial end (31b) of the first section. The second section (32) can extend and retract relative to the first section (31) along the axial direction of the hub (1) to adjust the axial height of the guide vane blade assembly (3). The guide vane assembly further includes a drive mechanism for driving the second segment (32) to extend and retract relative to the first segment (31) along the axial direction of the hub (1); the drive mechanism includes an electromagnet (7), an elastic element (10), and a magnetic element (8), one of the electromagnet (7) and the magnetic element (8) being disposed on the first segment (31) and the other being disposed on the second segment (32); the electromagnet (7) is used to attract the magnetic element (8) to drive the second segment (32) to retract relative to the first segment (31) along the axial direction of the hub (1); the elastic element (10) is used to drive the second segment (32) to extend relative to the first segment (31) along the axial direction of the hub (1).

2. The guide vane assembly according to claim 1, characterized in that: The first segment (31) and the second segment (32) are inserted into each other along the axial direction of the hub (1) so that the second segment (32) can extend and retract relative to the first segment (31) along the axial direction of the hub (1).

3. The guide vane assembly according to claim 2, characterized in that: The hub (1) has a first hub segment (11) and a second hub segment (12) connected sequentially along the axial direction. The first hub segment (11) and the second hub segment (12) are inserted into each other along the axial direction of the hub (1). The hub (1) is connected to one radial end (31a) of the first segment through the first hub segment (11). The end of the second segment (32) that is away from the outer ring (2) is connected to the second hub segment (12).

4. The guide vane assembly according to claim 1, characterized in that: When the hub (1) has a first hub segment (11) and a second hub segment (12) connected sequentially along the axial direction, One of the electromagnet (7) and the magnetic attractor (8) is disposed on the first hub section (11) to be connected to the first section (31) through the first hub section (11); the other of the electromagnet (7) and the magnetic attractor (8) is disposed on the second hub section (12) to be connected to the second section (32) through the second hub section (12).

5. The guide vane assembly according to any one of claims 1 to 4, characterized in that: The axial height of the guide vane blade assembly (3) is H, and the outer diameter is D, wherein H is greater than or equal to 0.08*D.

6. The guide vane assembly according to claim 5, characterized in that: H = a * D, 0.08 ≤ a ≤ 1.

7. The guide vane assembly according to any one of claims 1 to 4 and 6, characterized in that: The first segment (31) has a first sub-segment (311) and a second sub-segment (312) connected sequentially along the axial direction. The first segment (31) is connected to the second segment (32) through the second sub-segment (312). The second sub-segment (312) and the second segment (32) are both straight segments extending along the axial direction of the hub (1). The portion of each guide vane in the guide vane blade group (3) located in the first sub-segment (311) is the first blade portion (301). Each of the first blade sections (301) is twisted circumferentially along the hub (1), and the exit geometry angle (b) of each first blade section (301) is 90 degrees. The inlet geometry angle α of each first blade section (301) at different positions in the radial direction of the hub (1) satisfies: α = tan -1 (v) z / v T ), v z v is the axial velocity of the airflow. T The circumferential velocity of the airflow; and / or, each of the first blade portions (301) is bent radially along the hub (1) with a bending angle (c) of 50°-70°.

8. The guide vane assembly according to any one of claims 1 to 4 and 6, characterized in that: The outer ring (2) has an arc-shaped diffuser section on the air outlet side.

9. An axial flow fan, characterized in that: Includes the guide vane assembly (100) according to any one of claims 1-8.

10. The axial flow fan according to claim 9, characterized in that: It also includes a fan blade (6); the guide vane assembly (100) is located downstream of the fan blade (6) in the air outlet direction; The number of guide vanes in the guide vane blade group (3) is not an integer multiple of the number of blades in the wind vane (6).

11. A control method for the axial flow fan of claim 9 or 10, characterized in that: When the axial flow fan includes a drive mechanism, and the drive mechanism includes an electromagnet (7), an elastic element (10), and a magnetic attractor (8), one of the electromagnet (7) and the magnetic attractor (8) is disposed on the first segment (31), and the other is disposed on the second segment (32); the electromagnet (7) is used to attract the magnetic attractor (8) to drive the second segment (32) to retract relative to the first segment (31) along the axial direction of the hub (1); the elastic element (10) is used to drive the second segment (32) to extend relative to the first segment (31) along the axial direction of the hub (1), the control method includes the following steps: Detect the static pressure at the air inlet of the axial flow fan; The optimal axial height of the guide vane blade assembly (3) is determined based on the static pressure. Then, the magnetic force of the electromagnet (7) is adjusted to cause the elastic element (10) to extend and retract, thereby driving the second segment (32) to move along the axial direction of the hub (1) to adjust the axial height of the guide vane blade assembly (3) to the optimal axial height.

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